Posts Tagged ‘high frequency circuit board’

What is high frequency circuit board? Let’s discover its material, technical parameter, design guideline, production processes and recommended manufacturer.

What Is High Frequency Circuit Board?

High Frequency Circuit Board is a printed circuit board specifically designed to handle high-frequency signals (such as RF, microwave, and high-speed digital signals). Its core features include the use of low dielectric loss materials (e.g., PTFE, ceramic-filled substrates) and optimized layout design to achieve low signal attenuation, high signal integrity, and stable electromagnetic performance. This meets the stringent requirements of high-speed transmission and low noise in high-frequency scenarios such as 5G communications, radar systems, and satellite equipment.

What is the Best Material for High Frequency Circuit Board?

PTFE-Based Composites (e.g., Rogers 4350B, RO4003C)

• Features: Low dielectric constant (Dk ≈ 3.38–3.48), ultra-low dissipation factor (Df ≈ 0.002–0.0037), stable performance across GHz frequencies.
• Applications: Ideal for microwave/millimeter-wave systems (5G antennas, radar modules)
• Trade-offs: Higher cost and processing complexity (such as specialized drilling/etching techniques required).

Ceramic-Filled Substrates (e.g., Rogers RO4000 Series, Nelco N4000-13)

• Features: Enhanced thermal conductivity (0.6–0.7 W/m·K), low moisture absorption, and mechanical robustness.
• Applications: High-power RF amplifiers, automotive electronics (harsh environment resistance), and hybrid stack-ups with FR4 for cost optimization.
• Trade-offs: Stiffer than PTFE, may require thermal management design adjustments.

Hydrocarbon/Ceramic Blends (e.g., Isola IS680, Panasonic Megtron Series)

• Features: Balanced Dk (≈3.0–3.66) and Df (≈0.001–0.008), compatible with standard PCB fabrication processes.
• Applications: High-speed digital/RF co-design (e.g., 5G base stations, satellite comms), offering a cost-performance compromise.
• Trade-offs: Slightly higher Df than pure PTFE, limiting use in ultra-high-frequency (>50GHz) scenarios.

Liquid Crystal Polymer (LCP)

• Features: Ultra-low Dk (≈3.0), minimal moisture absorption, and flexible/rigid-flex compatibility.
• Applications: Miniaturized wearables, millimeter-wave modules (e.g., 28/39GHz 5G front-ends), and aerospace systems.
• Trade-offs: Premium pricing and limited availability for large-format boards.

High-Performance FR4 Variants (e.g., FR408HR)

• Features: Improved Dk (≈3.66) and Df (≈0.008) over standard FR4, cost-effective for mid-range frequencies.
• Applications: Budget-sensitive projects (e.g., IoT devices, low-tier RF systems) where FR4’s limitations are acceptable.
• Trade-offs: Unsuitable for >10GHz applications due to signal attenuation and impedance mismatches.How to Make a High Frequency Circuit Board?

High Frequency Printed Circuit Board Technical Parameter

‌Parameter Category‌	‌Design Requirements‌
‌Substrate Material‌	PTFE/Ceramic-filled Hydrocarbon/Modified PPO
‌Dielectric Constant (Dk)‌	2.2~3.5 (±0.05 tolerance)
‌Dissipation Factor (Df)‌	≤0.002 (@10GHz)
‌Trace Width/Spacing‌	3mil/3mil (minimum)
‌Impedance Control‌	±5% (100% impedance testing)
‌Copper Foil Type‌	RTF/VLP (roughness ≤1.5μm)
‌Layer Alignment Tolerance‌	±25μm
‌Surface Finish‌	ENEPIG (Ni layer >0.1μm)
‌Insertion Loss‌	≤0.5dB/inch (@40GHz)
‌Phase Consistency‌	±2° (@25GHz differential pairs)

How to Design a High-Frequency PCB?

1. Requirement Analysis & Specification Definition

• Frequency Range: 2.4GHz (Wi-Fi routers), 5GHz (5G base stations), millimeter wave (radar/satellite communications), different frequency bands correspond to different transmission characteristics;
• Signal Type: Digital signals (e.g., DDR5 clock lines require precise timing), RF signals (5G antennas require low-loss transmission), mixed signals (AD/DA interfaces require noise immunity);
• Power Level: High-power scenarios (>10W PA modules) require enhanced thermal design using metal substrates or thermal via arrays;
• Interface Standard: PCIe 4.0 (16GT/s data rate), HDMI 2.1 (48Gbps bandwidth), USB 3.2 (20Gbps rate), ensuring interface compatibility and signal integrity;

2. Material Selection & Stackup Design

• Material Type: PTFE substrate (Dk≈2.2, Df≈0.002, suitable for high-frequency), ceramic-filled substrate (Dk≈3.0-10, Df≤0.001, high-power scenarios), high-speed FR4 (Dk≈3.66, Df≈0.008, cost-sensitive);
• Stackup Design: Signal layer-ground layer-power layer alternating arrangement, high-frequency signal layers adjacent to ground layers to reduce crosstalk, ground layers must be continuous without splits;
• Dielectric Thickness: Thin dielectrics (3-5mil) for high-frequency bands (>10GHz, e.g., RO4350B), 8-12mil for mid/low-frequency;
• Copper Thickness: ≥1oz (35μm) for high-frequency signal layers to reduce loss, ≥2oz (70μm) for ground layers to enhance heat dissipation, power layers adjusted based on current requirements.

3. Layout Planning & Component Placement

• Components: RF modules (e.g., LNA, PA) placed near antennas to minimize transmission loss, high-speed chips (e.g., FPGA, CPU) placed near connectors to shorten signal paths;
• Signal Path: Minimize length of high-frequency signal lines, avoid 90-degree corners (use 135-degree or curved routing), serpentine routing compensates DDR clock line timing deviations (length matching error ≤5mil);
• Thermal Management: Thermal vias (≥10mil diameter) under high-power components or metal substrates (e.g., Aluminum PCB) to prevent hotspots;
• EMC: Sensitive components (e.g., crystals) kept away from noise sources (e.g., switching power supplies), high-frequency regions isolated with dedicated power supplies and filtering capacitors.

4. Routing Design & Impedance Control

• Differential Pair: Impedance strictly controlled at 100Ω (e.g., USB 3.0/PCIe), trace width/spacing ratio 1:1 (e.g., 5mil/5mil), length matching error ≤5mil;
• Microstrip/Stripline: 50Ω RF signal lines (trace width ≈8mil, dielectric thickness ≈5mil), 75Ω video signal lines (trace width ≈12mil), high-frequency lines avoid crossing split planes;
• Minimum Trace Spacing: ≥3× trace width (e.g., 5mil trace width requires ≥15mil spacing) to suppress crosstalk, high-frequency line spacing ≥λ/10 (e.g., 5GHz signal λ=60mm, spacing ≥6mm);
• Crossing Split Planes: High-frequency signal lines crossing split planes bridged via capacitors or vias to reduce reflections/radiation.

5. EMC Optimization

• Ground Via: Array spacing ≤λ/10 (e.g., 5GHz signal λ=60mm, via spacing ≤6mm) for low-impedance ground paths;
• Shielding Structure: Metal cavities (thickness ≥0.2mm) or shielding layers (copper foil + conductive adhesive) to suppress resonances and electromagnetic radiation, high-frequency regions shielded independently;
• Decoupling Capacitor: 0.1μF (high-frequency) + 10μF (low-frequency) paralleled near power pins (≤5mm) to reduce power noise;
• Filter: LC filters (e.g., π-network) suppress power noise, ferrite beads absorb high-frequency noise for signal purity.

6. Simulation Verification & Iteration

• Frequency Domain Simulation: ADS/HFSS analyze S-parameters (return loss ≤-10dB, insertion loss ≤1dB), radiation patterns (antenna optimization);
• Time Domain Simulation: SIwave/Altium verify signal integrity (eye diagram openness ≥80%, crosstalk ≤5%) for high-speed digital signals;
• 3D EM Simulation: CST Microwave Studio evaluates antenna performance, radiation leakage, and coupling effects to optimize layout/shielding;
• Iteration: Adjust layout/routing (e.g., add shielding, optimize impedance) based on simulation results until performance metrics are met.

7. Manufacturing Process Control & Testing

• Lamination Process: Precise control of dielectric thickness (tolerance ≤±5%) to avoid delamination and bubbles;
• Drilling Process: Microvia (0.15mm) copper plating uniformity (thickness variation ≤10%) to prevent via wall fractures and conductivity issues;
• Impedance Testing: TDR verifies impedance matching (error ≤±5%) for signal quality;
• Eye Diagram Testing: High-speed digital signal eye diagram analysis (eye height ≥800mV, eye width ≥80%UI), radiation scanning (anechoic chamber) confirms EMI compliance to regulatory standards.

How to Make a High Frequency Circuit Board?

1. Material Cutting & Selection: Select low-loss substrates (e.g., PTFE, ceramic-filled substrates), cut panels to design specifications, ensure clean edges without burrs to prevent stress cracks or signal transmission loss in subsequent processes.

2. Inner Layer Pattern Transfer: Use high-precision exposure machine (resolution ≤5μm) for inner layer pattern transfer, precisely remove excess copper with alkaline etching solution, control line width/spacing tolerance within ±10μm to ensure high-frequency signal path accuracy.

3. Lamination & Stacking: Stack multilayer boards and perform vacuum lamination, strictly control temperature (180-200℃) and pressure (300-500PSI) profiles to avoid interlayer bubbles or uneven dielectric thickness, ensuring impedance stability for high-frequency signal transmission.

4. Drilling & Plating: Use precision drill bit (hole diameter tolerance ±2μm) for through-hole/blind via drilling, control copper plating uniformity (thickness variation ≤10%) to prevent via cracking or conductivity issues, ensuring high-quality vertical interconnection for high-frequency signals.

5. Outer Layer Pattern Transfer: After copper plating thickening, transfer outer layer patterns, optimize line width/spacing (e.g., 50Ω microstrip requires precise matching of dielectric thickness and copper thickness) using impedance calculation software to ensure consistent impedance for high-frequency signal transmission.

6. Solder Mask Application: Apply liquid photo-imageable solder mask ink, form protective layer through exposure/development, reduce signal transmission loss and surface contamination, avoid excessive solder mask thickness affecting high-frequency signal radiation efficiency.

7. Surface Finish: Apply ENIG (Electroless Nickel Immersion Gold) or OSP (Organic Solderability Preservative) surface finish to enhance solderability and long-term reliability, prevent oxidation affecting high-frequency signal conductivity, ensuring solder joint quality and product longevity.

8. Testing & Verification: Perform TDR (Time Domain Reflectometry) for impedance matching (error ≤±5%), eye diagram analysis (eye height/width meets standards), radiation scanning (anechoic chamber testing for EMI compliance) to ensure high-frequency signal integrity and regulatory adherence.

9. Packaging & Shipping: Vacuum-pack for moisture/dust protection, include quality inspection report and material certificate (e.g., Dk/Df test data), ensure safe transportation and traceability, maintaining high-frequency PCB performance stability in real-world applications.

Why Choose Best Technology as High Frequency Circuit Board Manufacturer?

Reasons why choose us as high frequency circuit board manufacturer:

• 19-Year High Frequency PCB Manufacturing Expertise – Specialized in PTFE/hydrocarbon processing with core technologies (microvias, buried blind holes, hybrid pressing). Completed 5,000+ High Frequency PCB projects across 5G/radar/satellite.
• Certified Quality System – ISO 9001/14001/IATF 16949 certified, RoHS/REACH compliant. Regular customer/third-party audits maintain system effectiveness.
• Transparent Pricing & Cost Optimization – Leverage bulk procurement for raw material savings and lean production to minimize waste. Tiered pricing ensures industry-leading competitiveness with no hidden fees.
• 48-72 Hours Rapid Prototyping – Mature production lines + smart scheduling enable 7-10 day standard delivery, with urgent orders achievable in 2-3 days. Optimized supply chain ensures project timelines.
• Full-Cycle Technical Support – Free DFM analysis, in-process optimization, and post-sales troubleshooting. 24/7 engineer team resolves issues within 48 hours.
• Strict Quality Control – Raw material inspection, in-process IPQC, final AOI, environmental testing, impedance microsection, and third-party audits. Defect rate <0.3% surpasses industry norms.
• Customization Flexibility – Supports any-layer HDI design, custom impedance (50Ω±2%), finishes (ENIG/OSP), and thicknesses (0.1-3.0mm) for tailored solutions.
• Experience-Driven Problem Solving – 19-year fault database enables rapid diagnosis of common issues (e.g., signal loss, layer misalignment) with solutions to accelerate time-to-market.

Below is a photo of high frequency high frequency circuit board we made before:

Our High Frequency PCB Capabilities

Base material:	Rogers/Telfon
Board Thickness:	0.5mm~3.0mm(0.02″~0.12″)
Copper thickness:	0.5 OZ, 1.0 OZ, 2.0 OZ, 3.0 OZ
Outline:	Routing, punching, V-Cut
Soldermask:	White/Black/Blue/Green/Red Oil
Legend/Silkscreen Color:	Black/White
Surface finishing:	Immersion Gold, HASL, OSP
Max Panel size:	600*500mm(23.62″*19.68″)
Packing:	Vacuum/Plastic bag
Samples L/T:	7~9 Days
MP L/T:	8~10 Days

How to Get a Quote for Your Project?

List of materials required for quotation:

• Gerber files: Complete hierarchical data to ensure the design is complete.
• Design files: Original files in Altium/OrCAD format, reproducing layout details.
• BOM: Clearly specify component model, package, quantity, and supplier.
• Technical parameters: Dimensions, number of layers, line width/space, aperture, and board thickness.
• Material and process: Substrate type (e.g., PTFE), surface finish (ENIG), and copper thickness.
• Impedance requirements: Target value (e.g., 50Ω) and signal integrity indicators.
• Testing standards: Acceptance criteria such as impedance, eye diagrams, and radiation scans.
• Quantity and delivery: Order size and expected delivery time.
• Certification standards: Quality (e.g., IPC) and environmental (e.g., RoHS) compliance certifications.

Welcome to submit your files to get a quote via this email: sales@bestpcbs.com.