Posts Tagged ‘HDI PCB’

HDI PCB, HDI PCB Board for AI Server Motherboard

Tuesday, June 17th, 2025

Why choose HDI PCB for AI server motherboards? This guide explores HDI PCB technology from design to manufacturing, addressing signal integrity, reliability, and cost optimization for AI applications.

As a HDI PCB manufacturer, Best Technology delivers superior HDI PCB solutions for AI server motherboards through advanced manufacturing capabilities, rapid turnaround, and uncompromising quality. Our state-of-the-art facilities support ultra-fine 25/25μm trace/spacing and microvias with 50μm laser drilling precision, ensuring optimal signal integrity for high-speed AI workloads. We maintain a 98% first-pass yield rate through stringent process controls including automated optical inspection and impedance testing. Clients benefit from our optimized production flow achieving 15 to 20 percent faster lead times versus industry standards without sacrificing reliability. All boards undergo 100 percent electrical testing and thermal cycle validation. With dedicated engineering support from design to delivery, we help AI hardware developers accelerate time-to-market while meeting stringent IPC Class 3 standards. Our competitive pricing structure scales efficiently from prototyping to mass production. Contact our team today for a customized quotation tailored to your AI server PCB requirements: sales@bestpcbs.com.

What Is HDI PCB?

HDI PCB, short for High-Density Interconnect Printed Circuit Board, is a specialized type of circuit board designed to accommodate complex electronic designs with densely packed components and fine-line circuitry. HDI PCB achieves this through advanced manufacturing techniques like microvias, sequential lamination, and laser drilling, enabling higher signal integrity and reduced size compared to traditional PCBs. In AI server motherboards, HDI PCB technology becomes essential for handling high-speed data transmission and thermal management while maintaining compact form factors. The precision and reliability of HDI PCB make it ideal for applications requiring miniaturization without sacrificing performance, particularly in cutting-edge fields like artificial intelligence infrastructure. By integrating finer traces and tighter spacing, HDI PCB boards effectively address the escalating demands of modern AI server designs.

What Are Technical Parameters of HDI PCBs?

Technical parameters of HDI PCBs for AI server motherboards:

Minimum Aperture and Drilling Technology: HDI PCBs utilize laser-drilled microvias with diameters typically ≤150μm, enabling precise layer interconnections in compact spaces. Traditional PCBs rely on mechanical drilling for ≥200μm holes, limiting routing density.
Trace Width and Spacing: HDI PCBs achieve ultra-fine line widths and spacings of ≤75μm, allowing for tighter circuit routing and improved signal integrity. Traditional PCBs use ≥100μm traces, which occupy more surface area and restrict component density.
Pad Density and Component Integration: With pad densities exceeding 20 pads per cm², HDI PCBs accommodate high-pin-count components like BGAs and fine-pitch connectors. Traditional PCBs, with densities below 10 pads per cm², struggle to support modern AI hardware requiring dense I/O interfaces.
Interlayer Connection Methods: HDI PCBs employ advanced interlayer connections, including blind vias, buried vias, and stacked microvias, to optimize space and reduce signal path lengths. Traditional PCBs primarily use through-hole vias, which consume more board real estate and limit routing flexibility.
Material and Thermal Performance: HDI PCBs for AI servers incorporate high-Tg laminates and low-loss dielectric materials to withstand thermal stresses from high-power components. Traditional PCBs often use standard FR-4 materials with lower thermal stability, risking deformation under prolonged operation.
Signal Integrity and High-Speed Design: HDI PCBs are engineered for controlled impedance and low dielectric loss, critical for supporting multi-gigabit data rates in AI servers. Traditional PCBs, with their looser tolerances, may struggle with signal degradation at high frequencies.

How to Achieve 25Gbps Signal Integrity in Your HDI PCB Design?

Below are methods about how to achieve 25 Gbps signal integrity in your HDI PCB design:

Material Selection for Low-Loss Performance: Prioritize high-frequency laminates with low dielectric constants (DK) and dissipation factors (DF), such as Megtron 6 or Panasonic R5775. These materials minimize signal attenuation and skew at 25Gbps, ensuring cleaner data transmission across long traces. Avoid standard FR-4 for high-speed layers to prevent excessive insertion loss.
Layer Stack-Up Optimization: Design a symmetric layer stack-up with tightly coupled power and ground planes to reduce electromagnetic interference (EMI). Dedicate specific layers for high-speed differential pairs, isolating them from noisy power domains. Use sequential lamination to embed microvias close to signal layers, shortening return paths and improving impedance control.
Controlled Impedance Routing: Maintain precise trace widths and dielectric thicknesses to achieve 50Ω or 100Ω differential impedance. For 25Gbps signals, target 6-8mil trace widths with 4-5mil spacing for microstrip or stripline geometries. Leverage impedance calculation tools to validate designs before fabrication, ensuring consistency across the board.
Via Design for Minimal Stub Effects: Employ blind vias or backdrilled through-hole vias to eliminate via stubs, which cause reflections at high frequencies. Laser-drilled microvias (≤150μm diameter) reduce parasitics and enable denser routing. Avoid excess via counts in high-speed channels to prevent impedance discontinuities.
Differential Pair Routing: Route 25Gbps differential pairs with matched lengths (≤5mil mismatch) and consistent spacing (≥3x trace width) to minimize skew and crosstalk. Avoid sharp bends (use 45° angles) and maintain isolation from adjacent signals by ≥5x trace width. Implement length tuning with serpentine patterns only when necessary, keeping amplitudes minimal to preserve signal quality.
Power Integrity and Decoupling: Place low-ESL decoupling capacitors (0402 or 0201 packages) close to high-speed IC power pins. Use stitched ground planes and isolated power islands to reduce noise coupling. For AI server motherboards, distribute power via multiple low-inductance planes to handle transient currents from AI accelerators.
Thermal Management: Integrate thermal vias beneath high-power components (e.g., SerDes chips) to conduct heat to inner or outer layers. Use heavy copper planes (≥2oz) for power-hungry regions and ensure adequate airflow around the HDI PCB. Excessive heat can degrade signal integrity by altering dielectric properties.
Pre-Layout Simulation and Post-Layout Verification: Perform SI/PI simulations using tools like Ansys SIwave or Keysight ADS to model channel loss, reflections, and EMI. Validate designs with eye diagram analysis and compliance testing for standards like IEEE 802.3bj or CEI-25G-LR. Iterate on layouts based on simulation results to mitigate risks before prototyping.
Fabrication Tolerances and Documentation: Specify tight manufacturing tolerances (e.g., ±10% for impedance, ±2mil for trace/space) in your fab notes. Collaborate with PCB vendors experienced in HDI processes to ensure laser drilling accuracy and lamination consistency. Provide clear documentation on stack-up, via types, and controlled impedance requirements to avoid misinterpretation.

How to Optimize HDI Blind and Buried Design For High Precision Interconnects?

Here are methods about how to optimize HDI blind and buried design for high precision interconnects:

Prioritize Layer Stack-Up Symmetry: Design your HDI PCB with balanced layer counts above and below the core to minimize warpage and improve signal integrity. Symmetric stack-ups reduce residual stress during lamination, ensuring consistent via registration and reliability for blind and buried vias.
Optimize Blind Via Placement: Position blind vias near high-speed components to shorten signal paths and reduce parasitic capacitance. Avoid clustering blind vias in dense regions to prevent etching or drilling inaccuracies. Use staggered arrangements to maintain adequate spacing between adjacent vias.
Leverage Buried Vias for Density: Integrate buried vias to connect inner layers without occupying surface space, freeing up routing channels for critical signals. This approach is particularly effective for AI server motherboards requiring dense power distribution networks and high-speed interconnects.
Control Aspect Ratios: Limit blind via aspect ratios (depth-to-diameter) to ≤1:1 to ensure reliable plating and avoid voids. For buried vias, maintain aspect ratios ≤0.8:1 to prevent misregistration during sequential lamination cycles.
Use Laser Drilling for Precision: Employ UV or CO2 laser drilling for blind vias to achieve diameters as small as 50μm. This enhances routing flexibility in high-density BGA and fine-pitch connector areas. Verify laser drilling accuracy with microsection analysis before mass production.
Implement Backdrilling for Stub Reduction: Apply controlled-depth backdrilling to remove via stubs from through-hole vias used in high-speed channels. This technique reduces signal reflections and improves impedance continuity at 25Gbps and beyond.
Isolate Power and Ground Planes: Dedicate specific layers to power and ground planes near blind via regions to minimize noise coupling. Use stitched connections between planes to create low-impedance return paths for high-frequency signals.
Validate with Thermal Simulation: Simulate heat dissipation around blind and buried via areas using thermal analysis tools. Ensure copper fill and thermal vias are strategically placed to prevent hotspots near high-power components like AI accelerators.
Collaborate with Fabricators Early: Engage HDI PCB manufacturers during the design phase to align on capabilities such as laser drilling accuracy, lamination cycles, and plating uniformity. Provide detailed documentation on via types, stack-up requirements, and impedance targets.
Test for Signal Integrity: Perform time-domain reflectometry (TDR) and eye diagram testing on prototype boards to validate via performance. Focus on blind via transitions and buried via interconnections to identify potential impedance discontinuities.

Why Choose HDI PCB Board for AI Server Motherboard?

Reasons for why choose HDI PCB board for AI server motherboard:

Maximize Component Density: HDI PCBs enable tighter placement of high-pin-count components like BGAs and AI accelerators, freeing space for additional memory modules or cooling solutions. This density reduces the board footprint while supporting cutting-edge silicon.
Ensure Signal Integrity at High Speeds: With controlled impedance traces and low-loss materials, HDI PCBs minimize signal degradation in 25Gbps+ channels. This prevents data errors in AI workloads, where split-second precision drives real-time inference and training.
Reduce Power Consumption: Shorter signal paths and optimized via structures lower switching losses in high-frequency circuits. For AI servers operating 24/7, this efficiency translates to measurable savings in energy costs and thermal management expenses.
Improve Thermal Performance: HDI PCBs integrate thermal vias and heavy copper layers to dissipate heat from power-hungry AI chips. This prevents thermal throttling, ensuring consistent performance during peak computation periods like model training or large-scale simulations.
Enhance Reliability in Harsh Environments: Advanced HDI manufacturing processes, including laser drilling and sequential lamination, improve via reliability and reduce solder joint fatigue. For data centers with strict uptime requirements, this means fewer maintenance cycles and longer service life.
Support Future-Proof Scalability: HDI PCBs accommodate emerging interface standards like PCIe 5.0 and CXL without redesigns. Their modular layer stack-ups allow easy integration of next-gen AI accelerators, protecting your investment as technology evolves.
Streamline Supply Chain Efficiency: Partnering with HDI PCB specialists ensures access to advanced capabilities like microvia filling and embedded capacitance. This reduces reliance on multiple vendors, simplifying procurement and accelerating time-to-market for AI server products.

How to Improve HDI PCB Reliability for AI servers under Heavy Loads?

Here are tips about how to improve HDI PCB reliability for AI servers under heavy loads:

Select High-Performance Materials: Use laminates with high glass transition temperatures (TG ≥ 170°C) and low dielectric loss to resist thermal degradation during prolonged AI workloads. Incorporate ceramic-filled prepregs to enhance thermal conductivity and reduce z-axis expansion.
Optimize Layer Stack-Up for Thermal Management: Design symmetric layer stacks with embedded ground/power planes near high-speed layers to dissipate heat efficiently. Dedicate inner layers to heavy copper fills (≥2oz) for power distribution, minimizing voltage drop and heat buildup.
Implement Robust Via Structures: Strengthen via reliability with laser-drilled microvias filled with conductive paste or copper plating. Use staggered blind via arrays to reduce stress concentrations and prevent barrel cracking under thermal cycling.
Enhance Solder Joint Fatigue Resistance: Apply ENEPIG (Electroless Nickel Electroless Palladium Immersion Gold) surface finish to improve solderability and resist corrosion in high-temperature environments. Optimize BGA pad designs with non-solder mask defined (NSMD) geometries for better stress relief.
Control Impedance and Crosstalk: Maintain tight impedance tolerance (±5%) across differential pairs using coupled stripline geometries. Isolate high-speed channels from noisy domains with guard traces and stitched ground planes, reducing crosstalk in dense AI accelerator regions.
Incorporate Thermal Vias and Heat Slugs: Place arrays of thermal vias (≥0.2mm diameter) under power-hungry components like GPUs or HBM modules. Integrate copper heat slugs directly into the PCB stack-up to conduct heat to external heat sinks or liquid cooling systems.
Validate with Accelerated Stress Testing: Subject prototypes to thermal cycling (-55°C to +125°C, 1,000 cycles) and power temperature cycling (PTC) to simulate years of AI server operation. Use scanning acoustic microscopy (SAM) to detect delamination in hidden via structures.
Leverage Advanced Manufacturing Techniques: Partner with fabricators using plasma etching for via desmear, ensuring clean sidewalls for reliable plating. Require automated optical inspection (AOI) and X-ray systems to validate microvia integrity and layer registration.
Design for Manufacturability (DFM): Provide clear DFM guidelines to fabricators, including minimum annular ring (≥50μm for blind vias) and solder mask dam specifications (≥75μm). Avoid hairline traces (≤50μm) in high-stress areas to prevent etching undercut.
Monitor In-Field Performance: Implement built-in temperature sensors and current monitors on the PCB to track hotspots during AI training sessions. Use edge computing platforms to analyze real-time thermal data and trigger predictive maintenance alerts.

How to Improve Manufacturing Yield and Reduce Costs for AI Server Motherboard?

Below are methods about how to improve manufacturing yield and reduce costs for AI server motherboard:

Simplify Layer Stack-Up Design: Reduce unnecessary layers by consolidating power/ground planes and using buried vias to route inner signals. Fewer layers lower lamination cycles and material costs while simplifying impedance control for consistent yields.
Standardize Component Placement: Reuse proven BGA footprints and connector positions across AI server motherboard revisions. Standardization minimizes custom stencil and fixture costs while accelerating assembly line setup.
Optimize Panel Utilization: Maximize PCB panel space by arranging multiple motherboard designs with common outlines. Use edge-to-edge routing and shared coupons to reduce wasted material during etching and drilling.
Implement Design for Manufacturing (DFM) Rules: Enforce minimum trace/space (≥50μm) and annular ring (≥60μm) rules compatible with standard HDI processes. Avoid hairline features that require costly specialty equipment or yield-sapping etch compensation.
Adopt Plated-Through-Hole (PTH) Alternatives: Replace through-hole connectors with press-fit pins or surface-mount alternatives to eliminate costly PTH drilling and plating steps. This reduces cycle time and improves hole wall quality.
Leverage Automated Optical Inspection (AOI): Deploy AOI systems post-etch and post-soldermask to detect defects like under-etching or mask misalignment. Early detection prevents costly rework at later stages like assembly.
Negotiate Volume Contracts with Suppliers: Secure discounts on laminates, copper foil, and dry film by committing to annual usage volumes. Bundle orders for AI server motherboards with other products to leverage economies of scale.
Outsource Non-Core Processes: Partner with specialists for laser drilling, sequential lamination, and heavy copper plating instead of investing in in-house capacity. Focus internal resources on high-value design and testing.
Reduce Prototype Iterations: Use virtual prototyping tools to simulate via reliability, thermal performance, and signal integrity before fabrication. Fewer physical prototypes lower engineering costs and speed time-to-market.
Implement Lean Inventory Practices: Adopt just-in-time (JIT) delivery for raw materials and finished PCBs to minimize warehousing costs. Use kanban systems to align production with AI server assembly schedules.
Train Engineering Teams on Yield Fundamentals: Invest in training programs to teach designers about HDI process limitations, such as aspect ratio constraints or microvia plating challenges. Better-informed designs reduce scrap rates.
Recycle Scrap Material: Partner with recyclers to reclaim copper from etched-off panels and rejected boards. Revenue from recycled materials offsets raw material costs over time.

How to Solve Micro-Via and Fine-Line Production Challenges in HDI PCBs for AI servers?

Use Advanced Laser Drilling Systems: Invest in UV or CO2 laser drilling machines with high pulse frequency and beam steering capabilities. These systems achieve ≤25μm microvia diameters with minimal taper, ensuring precision for fine-pitch AI components.
Optimize Electroless Copper Plating: Implement direct metallization processes to eliminate traditional drill debris and improve via wall adhesion. This reduces voids in blind microvias, a common failure point in high-density AI server boards.
Control Etching Uniformity: Use alternating spray etchers with precise nozzle spacing and chemical concentration monitoring. This maintains consistent trace profiles (≥40μm lines/spaces) across large AI motherboard panels, preventing over-etching in fine-line regions.
Adopt Semi-Additive Process (SAP) for Fine Lines: Replace subtractive etching with SAP to build 35μm traces using pattern plating and flash etching. This method reduces sidewall undercut and improves yield in dense BGA breakout areas.
Improve Laminate Registration: Select laminates with low coefficient of thermal expansion (CTE ≤12ppm/°C) to minimize layer misalignment during sequential lamination. This ensures microvia-to-trace alignment within 25μm tolerance for AI accelerator interfaces.
Implement Automated Optical Shaping (AOS): Deploy AOS systems post-etch to repair neckdowns and open circuits in fine-line areas. This reduces scrap rates by addressing defects before layer stacking in complex HDI builds.
Partner with Process-Specialized Fabricators: Select PCB manufacturers with expertise in via-in-pad plating and laser ablation for buried microvias. Their experience reduces trial-and-error cycles, accelerating time-to-market for AI server motherboards.

Conclusion

In summary, HDI PCB technology is revolutionizing AI server motherboards with its high-density interconnects, superior signal integrity, and enhanced thermal management capabilities. From advanced micro-via designs to optimized blind/buried vias, these boards deliver the performance and reliability required for heavy AI workloads. For manufacturers seeking cutting-edge HDI solutions with cost-efficient production, Best Technology offers industry-leading expertise in ultra-fine 25/25μm trace designs and high-yield fabrication. Contact our team today for customized HDI PCB solutions that power your AI infrastructure with uncompromising quality and accelerated delivery: sales@bestpcbs.com.

Tags:HDI PCB, HDI PCB Board
Posted in best pcb, bestpcb, Special PCB | No Comments »

HDI PCB Design and Prototyping: 20-Year Experienced HDI PCB Manufacturer

Wednesday, May 28th, 2025

In the ever-evolving landscape of modern electronics, High Density Interconnect (HDI) PCBs have emerged as the cornerstone of advanced technological devices. From 5G communication hubs and artificial intelligence servers to intricate Internet of Things (IoT) devices, HDI PCBs play an indispensable role. As a seasoned HDI PCB manufacturer with two decades of industry experience, we take pride in offering end-to-end professional services, spanning from meticulous design to rapid prototyping, enabling our clients to gain a competitive edge in the market.

What is HDI PCB?

What is HDI PCB?The term “HDI PCB” stands for High Density Interconnect Printed Circuit Board, which succinctly captures its essence. When exploring the HDI PCB meaning and HDI PCB definition, we find that it represents a revolutionary advancement in printed circuit board technology. Unlike traditional PCBs, an HDI PCB board is engineered to achieve a significantly higher density of circuit connections within a limited space.

At the heart of an HDI PCB lies the High Density Interconnect technology. This technology leverages advanced manufacturing techniques such as laser drilling to create micro blind vias and buried vias. Micro blind vias connect the outer layers of the PCB to internal layers, while buried vias link internal layers without reaching the surface. These precise via structures enable a much denser routing of electrical traces, allowing for the integration of more components onto a single board.
For instance, in modern smartphones, where space is at an absolute premium, HDI PCBs play a crucial role. They allow manufacturers to pack components like processors, cameras, and wireless communication modules into a compact device while ensuring high – speed signal transmission between them. This is made possible by the high – density nature of HDI PCBs, which can handle complex electrical pathways with ease.
The full form of HDI PCB, High Density Interconnect Printed Circuit Board, emphasizes its dual focus on high – density interconnections and its role as a printed circuit board. By enabling more components to be placed in a smaller area, HDI PCBs not only contribute to the miniaturization of electronic devices but also enhance their performance. Faster signal speeds and reduced interference are additional benefits that come with the optimized design of HDI PCBs, making them indispensable in high – tech applications such as 5G base stations, high – performance computing servers, and advanced medical imaging equipment.
In summary, an HDI PCB is a cutting – edge printed circuit board solution that, through its high – density interconnect technology, meets the growing demands of modern electronics for smaller size, higher integration, and superior performance.

HDI PCB Manufacturer in China

HDI PCB Manufacturer in China, a global hub for electronics manufacturing, we have established ourselves as a leading HDI PCB manufacturer over the past 20 years. Our comprehensive service portfolio covers every aspect of the HDI PCB lifecycle.

Design
Our team consists of over 20 highly experienced engineers, each boasting nearly two decades of expertise in the field. Leveraging state-of-the-art EDA (Electronic Design Automation) tools, we conduct in-depth High-Speed Signal Integrity (SI) analysis and Power Integrity (PI) optimization. We offer free Design for Manufacturability (DFM) checks, ensuring that every design we create is not only innovative but also practical for production. Whether it’s planning the intricate stackup structure or precisely laying out blind and buried vias, we tailor high-precision and high-density PCB design solutions to meet the unique and complex functional requirements of our clients.
Prototyping
Recognizing the importance of speed in the product development cycle, we have set up a dedicated rapid prototyping production line. Employing advanced processes like laser drilling, mechanical drilling, and electroplating via filling, we can fulfill urgent prototyping requests within as little as 24 hours. Our stringent quality control measures include AOI (Automated Optical Inspection) and X-Ray non-destructive testing, guaranteeing that every prototype PCB adheres to the highest quality standards and is consistent with the design specifications.
Mass Production
Our 8,000-square-meter factory is equipped with fully automated production equipment and intelligent management systems, enabling us to achieve a monthly production capacity of up to 260,000 square feet (approx. 24,155 square meters) of HDI PCBs. From the procurement of high-quality raw materials to the delivery of finished products, we strictly comply with international quality system standards such as ISO 9001, IATF 16949, AS9100D, RoHS, Reach, and UL, ensuring the stability and efficiency of mass production.
Assembly
We provide one-stop PCB assembly services, covering a wide range of processes including SMT (Surface Mount Technology) pasting, through-hole soldering, and BGA (Ball Grid Array) packaging. With more than 10 SMT production lines, we offer free passive components and conduct comprehensive inspections, including DFM/DFA (Design for Assembly) checks, functional/ICT (In-Circuit Test) testing, X-Ray inspection, and online double AOI. Regardless of the order size, we offer turnkey PCB assembly services, delivering finished components that are fully functional and highly reliable.

Why Choose Us?

Advanced Design Capabilities
We utilize industry-leading EDA tools, which support any-order HDI design, making it possible for us to handle even the most complex wiring requirements. Our engineers stay updated with the latest industry trends and technologies, ensuring that our designs are always at the forefront of innovation.
Fast Prototyping Response
Our rapid prototyping service is designed to accelerate your product research and development cycle. With the shortest turnaround time of just 3 working days from design confirmation to sample delivery, you can quickly test and refine your product concepts.
Strict Quality Control
Quality is our top priority. With multiple international certifications, we have a comprehensive quality control system in place that monitors every stage of the manufacturing process, from raw materials to the final product. This ensures that every HDI PCB we produce meets the highest quality standards.

HDI Technology in PCB

The HDI technology in PCB is the key to unlocking their superior performance. Laser drilling, for instance, allows for the creation of extremely small and precise blind and buried vias. This not only reduces the number of board layers and overall size but also improves signal integrity and power integrity. As a result, HDI PCBs are the go-to choice for high-speed, high-frequency applications, such as 5G base stations, data centers, and high-performance computing servers.

HDI Flex PCB

HDI Flex PCB combine the best of both worlds – the high-density interconnection capabilities of HDI technology and the flexibility of traditional flex circuits. This makes them ideal for applications where space is at a premium and flexibility is required, such as in wearable devices (like smartwatches and fitness trackers), foldable smartphones, and medical devices with complex geometries.

HDI PCB Stackup

The stackup design of an HDI PCB is a critical aspect that significantly impacts its performance. When designing the stackup, our engineers carefully consider factors such as signal frequency, current magnitude, and heat dissipation requirements. For high-frequency signals, precise interlayer spacing and selection of appropriate dielectric materials are essential to minimize signal loss. In cases where high current flows, increasing the copper foil thickness of the power and ground layers ensures efficient power delivery. By carefully coordinating these factors, we can design stackups that enable HDI PCBs to operate stably and efficiently under various conditions.

Advantages and Disadvantages of HDI PCB

Core Advantages
High Integration: HDI PCBs can pack a large number of components into a small footprint, enabling the creation of thin and lightweight electronic devices, which are highly sought after by consumers.
High-Speed Transmission: Thanks to their optimized layout and shorter traces, HDI PCBs significantly reduce signal delay and interference, making them suitable for high-speed data transfer applications.
Reliability: With our mature manufacturing processes and strict quality control measures, the HDI PCBs we produce are highly reliable and can withstand the rigors of long-term use.
Existing Challenges
High Cost: The complex manufacturing processes, along with the need for specialized equipment and advanced technologies, contribute to a higher production cost compared to traditional PCBs.
Difficult Maintenance: In the event of a malfunction, repairing HDI PCBs requires specialized equipment and experienced technicians due to their intricate design and small component size.

HDI vs PCB

When compared to traditional PCBs, HDI PCBs offer several distinct advantages. In terms of physical structure, HDI PCBs have a much higher wiring density and can be up to 50% thinner than double-sided traditional PCBs. Electrically, they exhibit lower signal loss and can support high-speed interfaces like 5G and PCIe 5.0. However, traditional PCBs still have their place in the market. For products with lower performance requirements, traditional PCBs are preferred due to their lower cost and faster delivery times.

HDI PCB Manufacturing Process

Step 1: Raw Material Preparation
We carefully select high-quality copper-clad laminates and other essential raw materials. Each batch undergoes rigorous inspection to ensure that it meets our strict quality standards before being used in production.
Step 2: Laser Drilling
Using high-precision laser equipment, we create micro blind vias and buried vias, which are crucial for achieving the high-density interconnections characteristic of HDI PCBs.
Step 3: Electroplating Process
A uniform conductive layer is applied to the via walls and traces through an electroplating process, ensuring reliable electrical connectivity throughout the PCB.
Step 4: Pattern Transfer
The designed circuit pattern is transferred onto the PCB with high precision using advanced imaging techniques.
Step 5: Etching
Unnecessary copper layers are removed through an etching process, leaving behind the desired circuit traces.
Step 6: Solder Mask Application
A solder mask layer is applied to areas where soldering is not required, protecting the PCB from short circuits and environmental damage.
Step 7: Legend Printing
Various markings and characters are printed on the PCB to facilitate assembly, installation, and maintenance.
Step 8: Surface Treatment
The PCB surface undergoes treatment to enhance its solderability and resistance to oxidation, ensuring a reliable connection during the assembly process.

HDI PCB Design Guide

Designing an HDI PCB requires careful consideration of several key factors. Firstly, meticulous circuit layout planning is essential. Signal flow and component placement should be carefully arranged to minimize signal interference. Secondly, when designing blind and buried vias, the appropriate via diameter and depth must be determined based on the specific signal and current requirements of the project. Thirdly, power and ground design play a crucial role in ensuring the stability of the PCB. A well-designed power and ground plane can reduce noise and improve overall performance. Finally, it is vital to integrate the design with the manufacturing process, taking into account both performance requirements and manufacturing feasibility and cost.

HDI PCB Application

HDI PCBs have found widespread applications across various industries. In the consumer electronics sector, they are used in smartphones, tablets, smartwatches, and other portable devices, enabling manufacturers to create sleek and powerful products. In the communication industry, HDI PCBs are integral to 5G base stations, routers, and other network equipment, facilitating high-speed data transmission. In the medical field, HDI PCBs are used in precision medical instruments such as electrocardiographs, CT scanners, and surgical robots, where reliability and accuracy are of utmost importance.

If you’re in the market for high-quality HDI PCBs, look no further. Whether you need custom design services, rapid prototyping, or mass production, we have the expertise and capabilities to meet your requirements. For inquiries or to discuss your project, please feel free to email us at sales@bestpcbs.com. We are eager to collaborate with you and bring your innovative electronic products to life!

Tags:HDI PCB
Posted in best pcb, bestpcb, FR4 PCB, HDI PCB | No Comments »

What is pcb sbu technology? HDI PCB manufacturer

Friday, February 14th, 2025

What is pcb sbu technology? SBU technology in PCB refers to “Sequential Build Up”, which is a technology used to manufacture high-density interconnect (HDI) multi-layer PCBs. It achieves higher wiring density and smaller board size by stacking additional conductive and insulating layers layer by layer on the basis of traditional multi-layer boards and using micro-vias (blind or buried vias) to achieve inter-layer connections.

What is pcb sbu technology?

PCB SBU technology stands for Sequential Build Up technology. It is an advanced process used in the manufacturing of high-density interconnect (HDI) PCBs.

This technique involves building up multiple layers of a PCB in a sequential manner, typically starting from the inner layer and adding layers progressively.

Each layer is added using specialized processes that make it possible to create smaller vias, more complex routing, and finer features compared to traditional PCB manufacturing.

SBU technology is essential in HDI PCB production, which is commonly used in devices that require high performance in a compact form factor, such as smartphones, medical devices, automotive electronics, and other modern electronic systems.

By using SBU technology, multiple layers can be stacked with precision while maintaining the electrical performance and signal integrity required by these applications.

What is HDI PCB?

An HDI PCB (High-Density Interconnect PCB) is a type of printed circuit board that offers higher density and more compact designs.

HDI PCBs are designed to handle fine-pitch components, high-frequency signals, and miniaturized electronic devices. They use advanced manufacturing techniques such as microvias, blind vias, and buried vias, making them the preferred choice for high-performance applications.

HDI boards are typically characterized by:

Smaller and finer traces – Supporting higher component density.

Microvias – Very small holes used to connect different layers in the PCB.

Blind and buried vias – Vias that only connect specific layers, improving space utilization.

Stacked or staggered via construction – For reducing board size and increasing routing flexibility.

By leveraging HDI technology, manufacturers can create more compact and efficient PCBs that perform exceptionally well in the most demanding electronic applications.

What is a buried hole?

A buried hole is a via that connects two inner layers of a PCB but does not go through the entire thickness of the board. These vias are entirely enclosed within the PCB layers and are not visible on the outer surfaces.

Buried holes are commonly used in HDI designs to enable multi-layer connections while optimizing the space on the outer layers for components and routing.

How Buried Holes Benefit PCB Design:

Maximized board space – Since they don’t take up space on the outer layers.

Reduced signal interference – By isolating inner-layer connections from the external surface.

Improved electrical performance – Essential for high-speed, high-frequency designs.

Buried holes are particularly beneficial in high-performance electronic devices that require dense component placement without compromising the integrity of the signal paths.

What is a blind hole?

A blind hole is a via that connects an outer layer to one or more inner layers of the PCB, but does not extend all the way through the board.

It is “blind” because it doesn’t go all the way through the PCB like a through-hole. These types of vias are often used when connections need to be made between surface components and inner layers without occupying precious outer-layer space.

Benefits of Blind Holes:

Space-saving – No need for holes that go all the way through the board.

Enhanced routing flexibility – Allows for more efficient use of the board’s surface.

Reduced component size – Perfect for designs with high-density components that need a compact form.

Blind vias help ensure that HDI boards can be designed with multiple layers, allowing for more complex circuits without increasing board size. They are ideal for devices with multi-functional, high-density circuit layouts.

What is a microvia?

A microvia is a very small via used in HDI PCB designs to create electrical connections between the layers. Microvias are typically laser-drilled, allowing for precise and tiny holes that are ideal for high-density applications.

They generally have a diameter of less than 150 microns, making them perfect for high-frequency, high-speed circuits that need to minimize space without sacrificing performance.

Key Advantages of Microvias:

Reduced board size – Enables more compact designs without compromising performance.

Improved electrical performance – Allows for shorter signal paths and fewer signal losses.

Better signal integrity – Minimizes the risk of signal interference and distortion.

Enhanced routing flexibility – Provides designers with more options for creating high-density, complex circuits.

Microvias are indispensable for modern PCB designs that demand high performance, miniaturization, and advanced electrical features.

What are the advantages of Sbu technology?

Sequential Build-Up (SBU) technology offers several key advantages, especially in the production of HDI PCBs.

By allowing for the precise construction of multi-layered boards with intricate features, SBU technology helps manufacturers achieve designs that would be impossible with traditional PCB technologies.

Key Benefits of SBU Technology:

Enhanced Performance in Smaller Footprints – By using fine-pitch components, microvias, and blind or buried vias, SBU technology enables the creation of small, highly efficient circuits.

Faster Production Cycle – The sequential build-up process reduces the overall time required to produce multi-layer boards compared to conventional methods.

Cost-Effective for Prototyping – Ideal for low to medium-volume runs, where modifications can be made quickly without the need for large-scale tooling changes.

Better Signal Integrity – The small via sizes and precise routing make SBU technology particularly effective for high-speed, high-frequency designs.

Flexibility in Layer Design – SBU allows for a more flexible design process, offering greater options in terms of layer stack-ups and via types.

Overall, SBU technology empowers PCB designers to achieve advanced, high-performance circuits while maintaining cost-effectiveness and design flexibility.

What is the difference between PCB substrate and laminate?

The terms substrate and laminate are often used interchangeably in the context of PCB manufacturing, but they refer to different parts of the PCB construction process.

Substrate – The substrate is the core material of the PCB. It is typically made of fiberglass (FR4) or ceramic and provides the foundational structure on which the circuit layers are built.

Laminate – A laminate refers to the outer layer material that is bonded to the substrate. It is often a combination of resins and copper foil.

Key Differences:

Substrate is the primary base material, while laminate is used to build up the layers on top of the substrate.

Substrate provides mechanical support, whereas laminate contributes to the board’s electrical properties.

Both are crucial components in the production of HDI PCBs and other advanced circuit boards, ensuring strength, reliability, and functionality.

What is the difference between PCB and package substrate?

The main difference between a PCB substrate and a package substrate lies in their intended function and design:

PCB Substrate – Primarily used for circuit boards, these substrates provide structural support for the PCB’s electrical connections.

Package Substrate – This is used in chip packaging and provides connections between the chip and the external circuit.

The PCB substrate is mainly concerned with signal routing and electrical connections, while the package substrate focuses more on chip integration and interfacing with external systems.

Conclusion:

PCB SBU technology has revolutionized the way high-density interconnect (HDI) PCBs are designed and manufactured.

At Best Technology, we leverage our extensive expertise and advanced manufacturing capabilities to produce top-tier HDI PCBs with SBU technology. For inquiries, contact us at: sales@bestpcbs.com

Tags:HDI PCB, pcb sbu, sbu pcb
Posted in best pcb, bestpcb, FAQ, HDI PCB, PCB Technology | No Comments »

What are the stack-ups in HDI PCB?

Monday, November 11th, 2024

In the field of modern electronic manufacturing, high-density interconnect (HDI) technology has become a key factor driving the development of electronic products towards miniaturization and higher performance. The core of HDI technology lies in its unique stacked design, which not only greatly improves the space utilization of circuit boards, but also significantly enhances electrical performance and signal integrity.

The stacked-up design of HDI PCB allows multiple circuit layers to be connected through precisely controlled blind and buried holes, which have much smaller diameters than traditional PCB through holes. This connect method not only reduces the volume of the circuit board, but also increases the trace density, so that more and more electronic components can be integrated into a limited space.

In addition, the stacked design of HDI also optimizes the path of signal transmission. Due to the shorter signal transmission distance and the avoidance of unnecessary bends and corners, signal delay and loss have been effectively controlled. This is crucial for high-speed electronic devices as they require fast and accurate processing of large amounts of data.

In the manufacturing process, the stacked design of HDI also brings many challenges. In order to achieve high-precision buried/blind hole machining and interlayer registration, manufacturers must adopt advanced laser drilling technology and precision etching equipment. At the same time, in order to ensure the reliability and stability of the circuit board, strictly testing and verification of materials and processes are also required.

So what are the HDI stacking structures? This article will take you into an incredibly wonderful world…

1+N+1 Stack Up

1. Here, “1” (including the following “1”) refers to the layer number of blind holes (Blind via/ micro-via). And one layer blind hole always called a first step.

N refers to the number of non-blind hole layers in the inner layer (not necessarily just the Core), such as 4 layers, combined with 1, which is a 1-4-1 stacked structure. At the same time, if the N-layer is laminated, then this 1-4-1 laminated structure is called first-step-second-lamination (1 times N-layer lamination + 1 times outer layer lamination = 2 times, so it is called second lamination).

Does it make sense? If you have any questions, feel freely to leave a message or contact us at sales@bestpcbs.com.

2. Typical 1+N+1 stack-up

This kind of stack up shown as following is made by laminate a CCL sheet into 4 layers firstly and then laminate into 6 layers. It is also a common product on the market at present.

2+N+2 Stack Up

1. Here, 2 and N have the same meaning as 1-N-1, it will not be repeated again.

2. Typical 2+N+2 stack-up:

There are two types of second-step stack-up: stacked via and staggered via, which have different levels in difficulty, cost, and process.

2.1 Staggered via

Here is a stack-up of a staggered vias, this kind of structure has relatively lower cost and good reliability.

2.2 Stacked via

From the stack-up, it is not difficult to see the difference with staggered vias. This stacking structure requires drilling another blind hole on top of the blind hole, and the previous blind hole needs to be filled with copper or a material that can conduct electricity and resist laser drilling. This gives a rise to another technology, we will introduce in the later HDI electroplating process.

N+N Stack Up

1. Here, the “N” and the “N” in 1-N-1 or 2-N-2 have the same meaning.

2. Typical N+N stack-up

Although N+N stacking may not have blind holes, due to the special process and strict registration requirements, the actual production difficulty is no less than HDI technology.

Anylayer for Any Interconnection

1. The Any-layer means it can conduct at any layer, so how to achieve it?

2. Typical stack-up of Any-layer

From the section of the PCB as following, it can also be seen that how to stack each layer together to form a straight line is also a challenge, so the Anylayer process good or not depends on the registration ability of the manufacturer. Of course, the circuit uses this technology will definitely be very dense and fine, which gives rise to an advanced PCB process called MSAP.

So in summary, despite facing many challenges, HDI’s stacked design has become a key part of high-end electronic products. From smartphones to wearable devices, from high-performance computers to advanced communication systems, HDI technology is playing a crucial role. With the continuous advancement of technology and the increasing demand from consumers, we have reason to believe that HDI’s stacking will continue to lead the innovation trend in the field of electronic manufacturing.

Tags:HDI PCB
Posted in best pcb, bestpcb | No Comments »

What is the HDI PCB core thickness?

Wednesday, October 23rd, 2024

The core thickness range of HDI PCB (High Density Interconnect Circuit Board) mainly depends on its design and application requirements. According to different processes and application scenarios, the core thickness of HDI PCB can vary from 0.6mm to 1.0mm.

What is the standard thickness of a PCB core?

The standard thickness of PCB core boards usually includes the following specifications: 0.5mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.6mm, 2.0mm, 2.4mm, 3.2mm, 6.4mm. These thickness specifications are widely used in different electronic products and circuit board designs.

The thickness of PCB includes not only the thickness of the core board, but also the total thickness of all layers such as copper layer, solder mask layer and silk screen. The standard thickness ranges widely, from thinner 0.5mm to thicker 6.4mm, suitable for different application requirements.

Choosing the right PCB thickness is essential to ensure the performance and reliability of the circuit board. Thicker PCBs have higher mechanical strength and load-bearing capacity, and are suitable for products with high power and large electronic components, such as industrial, automotive, aerospace and military applications.

Ultra-thin PCBs are suitable for small electronic products such as smartphones, smart wearable devices and laptops due to their lightweight characteristics.

What is the thickness tolerance of a PCB core?

The thickness tolerance of a PCB core varies according to different thickness ranges.

For PCBs with a thickness of less than or equal to 1mm, the board thickness tolerance is ±10% of the board thickness. For example, a PCB with a thickness of 0.5mm has a tolerance of ±0.05mm; a PCB with a thickness of 0.8mm has a tolerance of ±0.08mm.

For PCBs with a thickness greater than 1mm and less than or equal to 1.6mm, the tolerance is ±0.14mm.

For PCBs with a thickness greater than 1.6mm and less than or equal to 2.0mm, the tolerance is ±0.18mm.

For PCBs with a thickness greater than 2.0mm and less than or equal to 2.4mm, the tolerance is ±0.22mm.

For PCBs with a thickness greater than 2.4mm and less than or equal to 3.0mm, the tolerance is ±0.25mm.

For PCBs with a thickness greater than 3.0mm, the tolerance is ±10%.

These tolerance standards apply to most PCB manufacturing processes, ensuring the stability and reliability of the PCB.

What is the difference between HDI and non-HDI PCB?

The main differences between HDI PCB and non-HDI PCB are their line density, size, production process and electrical performance. HDI PCB (High Density Interconnect PCB) has higher line density, smaller size and better electrical performance, while ordinary PCBs are lacking in these aspects.

First of all, the design and structure of HDI PCB are significantly different from ordinary PCBs. HDI PCB adopts higher line density and more complex circuit layout, which enables smaller size and lighter design. In contrast, ordinary PCBs have lower line density and are suitable for some application scenarios that do not require high line density.

In terms of production process, the manufacturing process of HDI PCB is relatively complex, including laser drilling, stacked copper plates, etching technology, etc., to achieve high-density interconnection and complex circuit wiring. The manufacturing process of ordinary PCB is relatively simple, generally using photolithography, etching process, etc.

In terms of electrical performance, HDI PCB uses technologies such as blind holes and buried holes to reduce signal transmission paths and improve the transmission rate and stability of electrical signals. In addition, HDI PCB also has better radio frequency interference, electromagnetic wave interference, electrostatic discharge and thermal conductivity performance.

Finally, the cost of HDI PCB is relatively high, mainly due to its complex manufacturing process and high technical requirements. The manufacturing cost of ordinary PCB is low, which is suitable for some application scenarios with low requirements for line density and technology.

How thick is a 2 layer PCB core?

The thickness of a 2-layer PCB core is usually 0.4mm.

PCB core is a base material composed of copper foil, solid resin material and glass fiber, with a certain hardness and thickness. Common PCB core thickness specifications include 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.6mm, 2.0mm, 2.4mm, etc.

Among the common specifications of Shengyi core boards, the thickness of 0.4mm is widely used. In addition, the performance of multi-layer PCBs does not directly depend on the number of layers, but more reflects the space requirements during design.

Are HDI PCB reliable?

HDI PCBs are reliable. HDI PCBs are manufactured using high-density and high-reliability interconnection technology, with higher line density and more complex circuit layout, which can achieve smaller and lighter electronic devices.

Compared with ordinary PCBs, HDI PCBs perform well in anti-interference ability and electromagnetic compatibility, and can effectively reduce the impact of external interference on signal transmission, while having higher reliability and longer service life.

The reliability of HDI PCBs is due to the high-quality substrates, solder mask and copper foil materials used, as well as strict manufacturing processes and quality control. These characteristics enable HDI PCBs to maintain stable performance and quality in various harsh environments.

In addition, the development trend of HDI PCBs is towards higher integration, higher signal transmission rate, better electromagnetic compatibility and optimized thermal management capabilities, which further enhances its application value in high-performance and high-density integration requirements.

What are the benefits of HDI PCB?

The main benefits of HDI PCB include high-density wiring, high-performance signal transmission, adaptability to high-frequency applications, miniaturization, and thinness. These characteristics make HDI PCB play a vital role in electronic devices, especially in high-end electronic products such as smartphones, tablets, and high-end computers.

First, HDI PCB has the characteristics of high-density wiring, which can achieve more circuit connections in a smaller space. This allows the design of electronic products to be more compact and meet application scenarios with extremely high space requirements.

Secondly, HDI PCB excels in high-performance signal transmission, can provide better signal transmission quality and electrical performance, and is particularly suitable for processing high-speed and high-frequency signals.

In addition, HDI PCB also has the advantages of miniaturization and thinness, which contributes to the thinness and miniaturization of electronic products, making the equipment more portable while maintaining high performance.

These benefits of HDI PCB are due to its advanced manufacturing process and technology. By adopting finer line widths and smaller apertures, HDI PCB achieves higher wiring density and signal transmission speed.

At the same time, by optimizing material selection and circuit design, HDI PCB can reduce the loss and reflection during signal transmission and improve the integrity and accuracy of the signal. In addition, HDI PCB also has better anti-interference ability and electromagnetic compatibility, which can effectively reduce the impact of external interference on signal transmission.

The application range of HDI PCB is very wide, including smart phones, tablets, laptops, medical equipment and communication equipment. Due to its high-density interconnection and excellent electrical performance, HDI PCB plays an important role in these fields, promoting the development of the PCB industry, so that more dense components can be arranged more closely on HDI boards.

What are the disadvantages of HDI PCB?

The main disadvantages of HDI PCB include high cost, complex production process, environmental sensitivity and possible quality problems.

First, the cost of HDI PCB is relatively high. This is because high-precision manufacturing technology and special materials are required in its manufacturing process, which all lead to its cost increase.

In addition, HDI PCB is usually used in high-performance equipment, and the value of these equipment itself is also high, which further pushes up the price of HDI PCB.

Second, the production process of HDI PCB is very complicated. Due to its high density of lines and components, the manufacturing of HDI PCB requires highly precise processes and equipment. This not only increases the difficulty of production, but may also lead to a longer production cycle, further increasing costs.

In addition, HDI PCB has certain requirements for the environment. Due to its delicate structure, HDI PCB is very sensitive to humidity and temperature changes in the environment. Improper storage or transportation conditions may cause the PCB to become damp or deformed, affecting its performance and reliability.

Finally, HDI PCB may have some quality problems. Due to the complexity of the production process, HDI PCB may have problems such as poor solderability, delamination, short circuit, open circuit, etc. These problems may need to be avoided through strict quality control and testing.

The core thickness of HDI PCB is an important parameter, which is directly related to the performance and application of PCB. When choosing the core thickness of HDI PCB, factors such as application requirements, design requirements and manufacturing process need to be considered comprehensively to select the appropriate core thickness.

Tags:HDI PCB, PCB, PCBA
Posted in best pcb, bestpcb, HDI PCB | No Comments »

High Density Interconnect PCB: Everything You Should Know

Friday, September 27th, 2024

What is High Density Interconnect PCB?

High density Interconnect (HDI) PCB is a printed circuit board designed to meet the growing needs of modern electronic products. It allows for higher component density due to the use of thinner lines, smaller through-holes, and precise component placement. These boards are particularly popular in industries where miniaturization is key, such as smartphones, medical devices, and military equipment.

The HDI board uses the micro-blind hole technology to realize the circuit board design with high line distribution density, which is especially suitable for applications requiring high performance and high reliability. Compared with traditional PCBs, HDI boards have significant advantages in terms of volume, weight, wiring density and electrical performance, which can meet the electrical requirements of high-speed signals, provide impedance control of alternating current characteristics, high-frequency transmission capacity and reduce unnecessary radiation (EMI).

HDI PCBs use a combination of advanced technologies such as laser drilling and sequential lamination to enable denser wiring without compromising performance. By integrating smaller, more efficient through-holes, HDI boards offer greater functionality on a smaller footprint than traditional PCBs.

What is the Difference Between Connect and Interconnect?

The terms “connect” and “interconnect” may seem similar but serve distinct functions in electronics. “Connect” typically refers to the linking of two points, components, or circuits. This could be as simple as joining a wire to a terminal.

On the other hand, “interconnect” deals with more complex connections, usually involving the linking of multiple circuits or components within a system. In the context of HDI PCBs, interconnectivity is crucial because it defines how different layers and components of the board communicate. HDI technology optimizes these interconnections to make the board more efficient in terms of space and performance.

What is HDI PCB Stackup?

The stackup in HDI PCBs refers to how the multiple layers of the board are arranged. Stackups are critical in determining the board’s performance, particularly when it comes to signal integrity, power delivery, and heat dissipation. HDI stackups often involve intricate configurations that vary depending on the design’s complexity and purpose. Here are the most common types:

HDI PCB (1+N+1)

This is one of the simplest forms of HDI stackups, where “1+N+1” means there are two layers of high-density interconnect (one on each side) sandwiching N layers of traditional PCB. This structure is often used in applications where moderate complexity is required, providing a balance between performance and cost.

HDI PCB (2+N+2)

In this configuration, there are two HDI layers on each side of the N traditional layers. This setup allows for greater flexibility in routing, especially for complex designs requiring more components. The additional HDI layers enhance the board’s ability to manage signal transmission efficiently, making it suitable for high-performance applications.

ELIC (Every Layer Interconnection): Most Complex HDI

ELIC takes HDI technology to the next level. In this configuration, every layer of the PCB can interconnect directly with any other layer. This is the most advanced form of HDI stackup, offering unparalleled design flexibility and performance. However, it is also the most complex and expensive option. ELIC is often used in cutting-edge technology applications such as aerospace and military equipment.

Other HDI Stackups

What are the Advantages of HDI PCB?

The main advantage of the HDI board is its high-density interconnect design, through the use of micro lines and highly compact layout, can achieve higher interconnection density, thereby accommodating more electronic components in a limited space, improving the performance and function of the board. This design makes HDI boards particularly suitable for applications requiring high performance and high functional density, such as high performance computing, data centers, and mobile communication equipment, to support high-speed data transmission and processing.

The design of the HDI board also focuses on improving the anti-interference ability and reliability of the circuit board, by using better signal integrity and power management technology, effectively reduce the impact of electromagnetic interference and power noise on the circuit.

However, HDI boards also have some limitations. First of all, compared with other advanced boards, the cost of HDI boards is usually lower, because HDI manufacturing technology helps to use advanced packaging technology, but its processing is more difficult, higher requirements for technology and equipment, which may increase a certain cost. In addition, the material choice of HDI board will also affect its performance and cost, such as FR4, PI and BT materials have advantages and disadvantages, need to be weighed according to the specific application needs.

5 Types of Vias in HDI PCB

HDI PCBs rely on several types of vias to achieve their high-density interconnections. Each type of via has its specific role in the design and manufacturing process.

Blind Vias

Blind vias connect an outer layer of the PCB to one or more inner layers but do not extend through the entire board. These vias allow for complex routing without using unnecessary space on the PCB’s inner layers.

Buried Vias

Buried vias are located entirely within the board, connecting internal layers without appearing on the outer surfaces. This is ideal for designs where surface area needs to be preserved for components, while still allowing inter-layer connectivity.

Microvias

Microvias are tiny vias, typically created using laser drilling, that connect adjacent layers of the PCB. These are essential for HDI designs as they save space while maintaining high-density connections. They can be used in stacked or staggered configurations to optimize space and signal flow.

Staggered Vias

Staggered vias are microvias that are offset from each other across layers. This design allows for more flexibility in routing and avoids overlapping, making it a popular choice for HDI PCBs that require complex routing.

Through Hole Vias

Though not exclusive to HDI designs, through-hole vias extend through the entire PCB, connecting all layers. While these vias occupy more space, they are sometimes necessary for power connections or when working with thicker boards.

What is the Difference Between PCB and HDI PCB?

The key difference between a traditional PCB and an HDI PCB lies in the design and manufacturing process. Traditional PCBs use through-hole technology and thicker traces, limiting the board’s ability to accommodate high-density components. HDI PCBs, by contrast, use finer lines, smaller vias, and advanced interconnect techniques to maximize component density. Here are some key differences between them:

Manufacturing Processes

The embedded via and blind via technologies used in the manufacturing process of HDI (High-Density Interconnect) boards allow for the addition of more layers without increasing the thickness of the board, thereby improving space utilization. In contrast, the drilling process for standard PCBs is relatively simple, but as the number of layers increases, the board thickness also increases accordingly. This difference means that HDI boards require more advanced equipment and higher technical requirements during production.

Space Constraints

In space-constrained devices, such as smartphones and portable electronics, HDI boards are the ideal choice because they can integrate more functions within a smaller size. HDI boards can achieve a line width of 2/2 mil and a 10-layer board thickness of below 0.8mm. Standard PCBs, due to their larger size and lower integration, may not be suitable for these applications. The line width and spacing of regular PCBs are generally limited to 3/3 mil, and their thickness also has certain restrictions.

Performance Requirements

For high-end electronic products that require high-speed signal processing and complex circuit designs, HDI boards offer better performance. Due to their high density and efficiency, HDI boards can meet the high-performance demands of modern electronic devices. Standard PCBs, on the other hand, may not be suitable for these applications because of their lower signal transmission quality and higher latency.

Different Layering Methods

HDI boards are created through continuous stacking and lamination, resulting in advantages such as being “light, thin, short, and small.” Electrical interconnections between layers are achieved through conductive vias, embedded vias, and blind vias, making the structure different from standard multilayer boards. Most HDI boards are laminated two or more times (except for special structures), while standard boards are typically laminated once.

PTH vs. HDI PCB

Plated Through Hole (PTH) technology is commonly used in traditional PCBs and involves drilling holes through the entire board to connect different layers. This method, while reliable, is limited in terms of design flexibility and component density.

HDI PCBs, on the other hand, use smaller vias such as microvias, blind vias, and buried vias. These allow for more efficient use of space, making HDI technology the go-to solution for high-density, multi-layer designs.

High Density Interconnect PCB Applications

Communication equipment
Computers and servers
Automotive electronics
Medical equipment
Industrial control equipment
Consumer electronics
ADAS system
Wireless connection module

For nearly 20 years, Best Technology have always been committed to providing overseas customers High Mixed, Low Volume products with Reliable Quality and Quick Delivery, and are determined to become one of most trusted partners in the field of printed circuit boards and PCBA. As an expert of HDI PCB manufacturer, we are so confident that we can provide the highest quality product that highly meet your specifications.

Tags:HDI PCB, high density interconnect pcb
Posted in best pcb, bestpcb, HDI PCB | No Comments »

hdi printed circuit board,hdi pcb manufacturer

Wednesday, August 14th, 2024

What is hdi pcb?

HDI stands for High Density Interconnect, which refers to high-density interconnect technology. HDI circuit board is a high-end printed circuit board with very high circuit density and complexity, which can achieve high-speed signal transmission and reliability design. The main features of HDI circuit board are multi-layer circuit, thin plate, small aperture, dense wiring and fine circuit. It is widely used in mobile phones, computers, network communications, automotive electronics and other fields. Bestpcb is a professional HDI manufacturer with 18 years of HDI manufacturing experience.

What are the advantages of hdi pcb

Higher line density: HDI PCB can support more circuit tracks, arrange more electronic components in a limited space, and achieve high-density interconnection.
Smaller device spacing: The micro-hole technology of HDI PCB allows smaller spacing between components, which is suitable for compact design.
Improve signal integrity: The advanced stacking layer structure is adopted to provide better signal transmission quality and reduce signal interference.
Improve reliability: The manufacturing process of HDI PCB improves the mechanical strength of the board, making it more durable and suitable for demanding application environments.
Improve circuit integration: More line connections and component arrangements are achieved in a limited circuit board space to meet the needs of modern products that are thin and compact.
Enhance signal transmission efficiency: The use of advanced wires and connection methods can increase the operating speed of electronic devices and reduce energy consumption.
Support more complex system design: High-density connection capabilities provide support for complex system design and give full play to the performance of electronic devices. ‌
Promote innovation in the electronics industry: The application of HDI technology has promoted the innovation and development of the electronics industry, making electronic equipment more intelligent and efficient. ‌
Smaller size: It can complete a large number of circuit connections in a smaller space, meeting the needs of electronic products for lightness and portability. ‌
Higher signal transmission speed: The high-density line design allows signals to be transmitted quickly in a short time, improving the system operation speed and response speed.

Why does HDI PCB need via filling and plating?

‌Via filling plating plays a vital role in ‌HDI PCB manufacturing, with the main purpose of improving ‌electrical performance, connection reliability, operating frequency, and avoiding electromagnetic interference. This technology fills the blind holes of HDI PCB with conductive materials through the electroplating process to form a conductive path, which improves the performance and reliability of electronic equipment.

Improve electrical performance: Via filling plating can improve the electrical performance of HDI PCB, especially in high-frequency circuit board design, which is crucial for improving connection reliability, operating frequency and avoiding electromagnetic interference.
Via plugging and electrical interconnection in one step: Via filling plating technology combines via plugging and electrical interconnection, avoiding the defects caused by resin via filling, and also avoiding the CTE difference caused by other materials via filling.
Improve efficiency: Compared with resin via filling or other materials via filling, via filling plating has a simpler process and higher efficiency.
Process flow and technical challenges of via filling plating
Process flow: including steps such as tank preparation, setting of electroplating process control parameters, and analysis of potion addition.
Technical challenges: including positioning accuracy issues and electroplating quality issues, which need to be solved by strictly controlling parameters such as electroplating time and current density.

Application scenarios of hole filling electroplating

First-order HDI: Suitable for electronic devices with less complex circuits.
Second-order and above blind hole electroplating copper filling: Suitable for more complex electronic devices, such as mobile phones, laptops, etc.
Comparison between hole filling electroplating and full-board electroplating
Full-board electroplating: Although it can provide a uniform surface copper thickness distribution, it may encounter the problem of residual dry film on the board surface or in the hole during pre-treatment, resulting in some areas unable to be plated with copper. In addition, the etching process after full-board electroplating may cause quality defects such as side etching and fine lines.
Hole filling electroplating: Compared with full-board electroplating, hole filling electroplating is more accurate in filling blind holes, avoiding the problems that may be encountered in full-board electroplating, while simplifying the process and improving efficiency.

Materials of HDI PCB

The materials of HDI PCB mainly include coated copper foil (RCC), prepreg, copper foil, etc.

Resin-coated copper foil (RCC): This is a material that coats a special resin film layer on electroplated copper foil, used for HDI insulation layer. The characteristics of RCC include no glass dielectric layer, easy laser and plasma micro-hole forming, extremely high peel strength and good toughness, suitable for micro-narrow line etching. Laser drilling is performed on RCC, and the aperture shape formed is an inverted trapezoid, and the general aperture size is 0.076-0.10 mm. The use of RCC makes HDI PCB more widely used in small portable products, such as mobile phones, digital cameras, laptops, etc.

Prepreg and copper foil: These are basic materials in HDI PCB manufacturing, there are no special requirements, and they are suitable for different types of HDI PCB structures. The inner layer circuits are generally 1 ounce copper thick, while the outer layer circuits are plated with half an ounce of base copper to 1 ounce of finished copper thickness. The thickness of the board is usually thinner to meet the miniaturization requirements of HDI PCB.

Other materials: In addition to the main materials mentioned above, the manufacture of HDI PCBs may also involve other materials, such as FR4, PI (polyimide), BT, etc. These materials are selected according to specific application requirements. For example, FR4 has good electrical and mechanical properties and is suitable for most general applications; PI has higher heat resistance and chemical corrosion resistance, and is suitable for high temperature, high humidity and strong acid and alkali environments, but it is more expensive and difficult to process; BT combines good electrical properties, mechanical properties and thermal stability, and is suitable for application scenarios that require higher heat resistance.

Classification of HDI circuit boards

HDI circuit boards are mainly divided into first-order, second-order, third-order, high-order (including fourth-order and above) and Anylayer HDI. ‌

First-order HDI circuit boards mainly include single-sided or double-sided micro-hole processes, and the circuit layer has only one layer. ‌This type of HDI circuit board is suitable for applications with high requirements on cost and space, such as consumer electronics. ‌
Second-order HDI circuit boards contain two circuit layers, which are more complex but also more powerful than first-order HDI circuit boards. They can handle higher signal frequencies and are suitable for applications that require high performance, such as high-end communication equipment and computer hardware. ‌
Third-order HDI circuit boards contain three circuit layers. They are the most complex type at present. They can handle the highest signal frequency and the maximum data transmission rate. They are usually used in applications that require the highest performance, such as aerospace and military equipment. ‌
High-order HDI (including fourth-order and above) The applications of third-order or fourth-order HDI in electronic terminal products are more, while those above fourth-order are mostly converted to Anylayer structure. ‌
Anylayer HDI refers to HDI of any order/any layer. Compared with PCB boards with traditional lamination processes, HDI can reduce costs to a lower level when the stacking density exceeds eight layers. It also has higher electrical performance and signal accuracy, and significantly improves the performance of electromagnetic waves and radio frequency interference, electrostatic discharge and heat conduction in interconnection and relay transmission.

HDI PCB Process Flow

The process flow standards of HDI PCB mainly involve the application and processing technology of high-density interconnection technology (High Density Interconnection Technology, HDI for short), including first-order, second-order and third-order processes. Specifically, the HDI PCB process flow includes the following key steps and characteristics:

First-order process (1+N+1): This is a basic high-density interconnection technology that manufactures multi-layer boards through build-up and micro-blind via technology.

Second-order process (2+N+2): Further development on the basic technology, adding more layers and complexity.

Third-order process (3+N+3): Represents the highest stage of HDI technology, with extremely high layers and interconnection density

Differences between HDI PCB and ordinary PCBs

Differences in circuit design:
HDI PCB adopts a more sophisticated circuit design, with smaller line width and spacing, and smaller aperture, which can integrate more electronic components and realize more complex circuit functions. ‌
The blind, buried and stacked hole designs of HDI PCB greatly improve the utilization rate and signal transmission performance of the circuit board.
Differences in manufacturing process:
The manufacturing process of HDI PCB is more complicated, requiring high-precision processes such as laser drilling technology, hole filling electroplating technology and photolithography technology.
The manufacturing cost of HDI PCB is relatively high, but the performance and reliability are also higher. ‌
Differences in application:
Due to its high density and high performance, HDI PCB is widely used in high-end electronic products, such as smartphones, tablets, high-end communication equipment, etc.
Ordinary PCB is mainly used in low-end electronic products and general electronic equipment.
Characteristics and application scenarios of HDI PCB:
HDI PCB has high-density wiring, multi-layer structure, high-precision manufacturing process and excellent electrical performance, which can meet the extremely high requirements of high-end electronic products for size, weight, performance and reliability.
HDI PCB is widely used in smart phones, tablet computers, high-end communication equipment and other fields, promoting the continuous development and upgrading of electronic products.

Application of HDI PCB

HDI PCB (High Density Interconnection Printed Circuit Board) is widely used in multiple industries, including medical equipment, mobile phones, laptops, automotive electronics, computer industry, and future 5G technology fields

Medical equipment: The application of HDI PCB in medical equipment, such as sphygmomanometers and ultrasonic imaging systems, achieves accurate measurement of blood pressure and high-definition imaging of the internal structure of the body, providing patients with timely and accurate diagnosis and treatment information. ‌
Mobile phone industry: With the increasingly miniaturized design of mobile phones, HDI PCB is widely used in transceiver modules, motherboards, SIM card interfaces, fingerprint recognition modules and other parts of mobile phones due to its high density, high quality and high reliability. ‌
Computer industry: In the computer industry, the application of HDI PCB improves the performance of computers, especially in the fields of high-speed algorithms and multimedia applications, and adapts to the miniaturization trend of computer equipment2. ‌
Automotive electronics: HDI PCB has broad application prospects in the field of automotive electronics. In addition to the dominant mobile phone market, it also involves multiple fields such as automobiles, modules and artificial intelligence, demonstrating its key role in complex electronic systems. ‌
Future development trends: With the advent of 5G technology, the demand for HDI PCB will continue to increase, requiring higher speeds and frequencies while adapting to smaller and thinner device designs. Research new micro HDI PCB boards to adapt to future development trends. ‌

Tags:HDI circuit boards, HDI PCB, PCB
Posted in best pcb, bestpcb, FR4 PCB, HDI PCB | No Comments »

Do You Know What Is HDI Board?

Thursday, August 10th, 2023

HDI boards are a type of printed circuit board (PCB) technology that enables higher circuit density and smaller form factors compared to traditional PCBs. HDI boards are commonly used in applications where space is limited, such as mobile devices, wearables, and aerospace systems.

Best Technology has rich experience in HDI rigid flex pcb manufacturing, below is one of our 7 layers HDI rigid flex pcb.

In Best Technology, our HDI board usually has the blind holes or buried holes, and the minimum hole size usually is 0.1mm. This board has the blind and buried holes, and the minimum hole size is 0.1mm. 100 ohm differential impedance control with 50 single ended impedance control. It’s surface finish is ENIG, 1oz copper for outer layers, 1/2oz copper for inner layers, green solder mask with white silkscreen. total thickness is 1.4mm.

Here are some key features and aspects of HDI boards:

High Density: HDI boards are designed to accommodate a large number of densely packed components and interconnections. They typically have multiple layers with high routing density, allowing for more complex circuitry in a smaller footprint.

Microvias: HDI boards extensively use microvias, which are very small holes drilled into the board to create electrical connections between different layers. Microvias are smaller in size compared to traditional vias, allowing for increased routing density.

Staggered and Stacked Microvias: HDI boards employ different types of microvias, including staggered and stacked microvias. Staggered microvias connect adjacent layers, while stacked microvias connect non-adjacent layers, providing even higher routing density.

Blind and Buried Vias: HDI boards often utilize blind and buried vias, which are vias that do not extend through the entire board. Blind vias connect an outer layer with one or more inner layers, while buried vias connect inner layers only. These vias help optimize space and increase routing capabilities.

Fine Pitch Components: HDI boards support the use of fine pitch components, such as microcontrollers, ball grid array (BGA) packages, and small surface-mount devices (SMDs). The high routing density and smaller features of HDI boards make them suitable for accommodating these tiny components.
Increased Signal Integrity: HDI boards can provide improved signal integrity due to shorter trace lengths and reduced noise interference. The compact design minimizes signal loss and impedance mismatches, allowing for better performance in high-frequency applications.
Design Considerations: Designing HDI boards requires expertise in factors such as layer stacking, via types, trace widths, and clearances. Advanced design software and manufacturing techniques are often employed to ensure precise alignment and reliability of the intricate interconnections.
Manufacturing Challenges: HDI boards can be more challenging to manufacture compared to standard PCBs. The use of smaller features and complex layer structures requires specialized fabrication techniques, such as laser drilling, sequential lamination, and precise registration control.

HDI technology has become increasingly prevalent in the electronics industry, enabling the development of smaller, lighter, and more sophisticated devices. It offers enhanced electrical performance, improved reliability, and greater design flexibility. If you have any comments about the HDI board, please feel free to contact Best Technology Team e-mail: sales@bestfpc.com.

Tags:flex circuit, HDI PCB
Posted in best pcb, bestpcb, HDI PCB, PCB News, PCB Technology, Rigid Flex Circuit | No Comments »

Do You Ever Know High Density Interconnect PCBs?

Tuesday, December 31st, 2019

HDI PCB (High Density Interconnector PCB), is a printed circuit board having a relatively high line distribution density using the micro-blind and buried hole technology.

It is a process that includes an inner layer line and an outer layer line, then uses a hole and a metallization in the hole to realize a joint function between the inner layers of each layer.

With the development of high-density, high-precision electronic products, the requirementsÂ of high-density and high precision are imposed on printed circuit boards. The most effective way to increase the density of pcb is to reduce the number of through holes, and to accurately set the blind holes and buried holes to achieve this requirement, thereby an HDI PCBÂ came into being.

HDI PCBs are finding their way into a growing number of products:

Military communications devices and other strategic equipment

Aerospace â€“ smaller space requirements and light weight are ideal for such applications

Computers and smartphones â€“ phones and computers are taking full advantage of smaller profiles, reduced weight, and increased functionality, made possible through the integration of HDI circuits.

Medical equipment â€“ diagnostic and monitoring equipment has become more reliable and expanded with technical features that aid medical teams with patient treatment, and all of this is powered by HDI PCBs and advanced software.

Benefits of HDI PCB

HDI PCB utilizes buried or blind vias, or a combination, and may also incorporate microvias with an incredibly small diameter. This facilitates the incorporation of more technology in less space, with fewer layers. Multi-layer HDI PCB are also in common use, with many layers being accommodated through various construction methods utilizing blind, buried, stacked, and staggered vias.

With smaller components and blind via in pad technology, components may be placed closer together, resulting in faster signal transmission rates while also reducing crossing delays and signal loss. These are key considerations that generate improved performance of HDI PCBs.

HDI PCBs are preferred for applications where space, performance, reliability, and weight are concerns. This makes them more suitable for nearly every application related to electronics, consumer products, computers, and aeronautics.

Multi-layer HDI PCB can provide strong interconnection of stacked vias, resulting in high levels of reliability, even in more extreme environments.

Considering this, do you ever think about choosing HDI PCB on your next project?

Tags:HDI PCB
Posted in FAQ, Our News, PCB News, PCB Technology, Uncategorized | No Comments »