Archive for the ‘Special PCB’ Category

Key Challenges in Solder Mask Printing for Heavy Copper PCBs

Tuesday, May 23rd, 2023

As the demand for higher power and miniaturization of electronics increases, so does the need for Heavy Copper Printed Circuit Boards (PCBs). From our last blog – Why choose Heavy Copper PCB for your High Current Project, we know the heavy copper PCBs are defined as those with copper thicknesses greater than 3 oz. These PCBs are designed to withstand high current and thermal loads, making them suitable for power electronics applications. However, the increased copper thickness also poses challenges during the solder mask printing process.

(16_layers_heavy_copper_PCB_with_10oz_each_layer)

Understanding solder mask

Solder mask (short for S/M in the industry) is a protective coating applied to PCBs to prevent solder bridges and improve solder joint quality. The solder mask is coated to the PCB surface using a screen-printing process, where the desired pattern is created using a stencil and the solder mask ink is then deposited onto the PCB. The ink is then cured, either through heat baking or UV light, to form a solid coating.

There are several types of solder mask materials available, including epoxy, acrylic, and liquid photo imageable (LPI) solder mask. Each type has its advantages and disadvantages, depending on the application requirements.

The benefits of using solder mask in PCB manufacturing include increased reliability, improved solderability, and reduced risk of short circuits and corrosion. The solder mask we usually use is Taiyo, which has high reliability and excellent heat resistance.

(Solder_mask_manually_printing)

Challenges in solder mask printing of heavy copper PCBs

While solder mask printing is a critical step in PCB manufacturing, the increased copper thickness in heavy copper PCBs presents several challenges for printing process as I mentioned before. It’s difficult to apply enough solder mask to cover thick copper pattern and base material with severe height difference.

1. The high copper thickness and thermal conductivity of heavy copper PCBs make it difficult for the solder mask ink to adhere properly to the surface. This can result in insufficient coverage and registration accuracy, which can affect the overall quality and reliability of the PCB.

2. The high copper thickness can cause stress on the solder mask, leading to mask cracking and peeling. The navigation mark on the substrate has specific ink thickness requirements due to limitations in the ink thickness that can be applied to the substrate. If the ink thickness on the substrate is too thick, it may result in solder resist cracks in the substrate position after the printed circuit board is soldered. This can occur during reflow soldering or thermal cycling, resulting in poor solder joint quality and reduced reliability.

3. The thick solder mask is also more difficult to exposure and develop. If the exposure energy is too weak or not enough, then some undercut problem may happen.

How to overcome this challenge?

To address these challenges, it is essential to choose the right solder mask materials and optimize the application process.

  • Choosing the right solder mask materials is crucial for ensuring proper adhesion and coverage on heavy copper PCBs. LPI solder mask is often preferred for heavy copper PCBs due to its excellent adhesion and thermal stability. However, epoxy and acrylic solder mask materials can also be used with proper surface preparation.
  • Optimizing the solder mask application process can also help address the challenges of heavy copper PCBs. This can include using a thinner stencil for improved registration accuracy and applying multiple coats of solder mask for better coverage. Advanced solder mask technology, such as laser direct imaging (LDI), can also help improve registration accuracy and reduce the risk of mask cracking and peeling.
  • Optimizing the printing process, now in Best Technology, we always make the substrate first, fill the substrate with the solder mask and then treat it as a normal PCB for normal printing solder mask.
(Solder_mask_printing)

If you are in the process of designing a complex multi-layer heavy copper PCB and are looking for a high-quality and experienced manufacturer, feel free to reach out to us at sales@bestpcbs.com, Best Technology can support you by OEM and ODM service to ensure your design is cost-effective and can be easily manufactured.

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Why choose Heavy Copper PCB for your High Current Project?

Tuesday, May 16th, 2023

In the world of electronics, printed circuit boards (PCBs) play a vital role in connecting and powering various components. They are the backbone of every electronic device, from smartphones to industrial machinery. When it comes to designing a PCB for a project, the thickness of the copper layer is an important consideration. Heavy Copper PCB, also known as Thick Copper PCB, has become increasingly popular in charging automotives due to their unique features and benefits. In this article, we will discuss why consider heavy copper PCBs for your high current project.

What a Heavy Copper PCB is?

A heavy copper PCB is a circuit board with an unusually thick copper layer, usually exceeding 3 ounces per square foot (oz/ft²). By comparison, standard PCBs typically have a copper layer thickness of 1 oz/ft². Heavy copper PCBs are used in applications where high current is needed, or the board needs to withstand mechanical and thermal stress.

(Heavy_copper_PCB)

Benefits of Heavy Copper PCBs

  • High Current Capacity

The thicker copper layer in a heavy copper PCB allows for a higher current capacity. This makes it ideal for high-power applications such as power supplies, motor controllers, and industrial equipment. Heavy copper PCBs can carry up to 20 amps or more, compared to the standard 5-10 amps of a regular PCB.

  • Thermal Management

Heavy copper PCBs are known for their excellent thermal management capabilities. The thicker copper layer allows for better heat dissipation, reducing the risk of overheating and component failure. So that they can generate a lot of heat for the end-application.

  • Durability

Heavy copper PCBs are more robust and durable than standard PCBs. The thicker copper layer provides better mechanical support, making them resistant to damage from vibration, shock, and bending. This makes them suitable for harsh environments and industrial applications.

  • Increased Flexibility

Heavy copper PCBs offer increased design flexibility compared to standard PCBs. The thicker copper layer allows for more complex and compact designs, reducing the overall size of the board. This makes them ideal for applications where space is limited, that means you can make a very heavy copper while the size is very small.

  • Better Signal Integrity

The thicker copper layer in heavy copper PCBs provides better signal integrity. This reduces the risk of signal loss and interference, resulting in more reliable and efficient circuit performance.

Copper thickness design for a Heavy Copper PCB?

Due to the thickness of copper in heavy copper PCB is thick then normal FR4 PCB, then it is easily to be warped if the copper thickness is not match each other in symmetrical layers. For example, if you are designing an 8 layers heavy copper PCB, then the copper thickness in each layer should follow L8=L1, L7=L2, L6=L3, L5=L4 standard.

Additionally, the relationship between minimum line space and minimum line width also should be considered, follow the design rule will help to smooth production and shorten the lead time. Below are the design rules between them, LS refers to line space and LW refers to line width.

(Heavy_copper_design_rule)

Drill hole rules for heavy copper board

A plated through hole (PTH) in printed circuit board is to connect top and bottom side to make them electricity. And when the PCB design has multi copper layers, the parameters of holes must be considered carefully, especially hole diameters.

In Best Technology, the minimum PTH diameter should be >=0.3mm while the copper ring annular should be 0.15mm at least. For wall copper thickness of PTH, 20um-25um as default, and maximum 2-5OZ (50-100um).

(16L_heavy_copper_PCB_with_35um_copper_in_via_holes)

Basic parameters of Heavy Copper PCB

Here are some basic parameters of heavy copper PCB, hope this can help you to understand Best Technology’s capability better.

  • Base material: FR4
  • Copper thickness: 4 OZ~30 OZ
  • Extreme Heavy Copper: 20~200 OZ
  • Outline: Routing, punching, V-Cut
  • Solder mask: White/Black/Blue/Green/Red Oil (Solder mask printing is not easy in heavy copper PCB.)
  • Surface finishing: Immersion Gold, HASL, OSP
  • Max Panel size: 580*480mm (22.8″*18.9″)

Applications of Heavy Copper PCBs

Heavy copper PCBs are used in a variety of applications, including:

  • Power supplies
  • Motor controllers
  • Industrial machinery
  • Automotive electronics
  • Aerospace and defense systems
  • Solar inverters
  • LED lighting
(Heavy_copper_PCB_for_high_power_supply)

Choosing the right PCB thickness is crucial for the success of any project. Heavy copper PCBs offer unique features and benefits that make them ideal for high-power and high-temperature applications. If you want to ensure the reliability and performance of your project, consider using heavy copper PCBs. Best Technology has more than 16 years manufacturing experience in heavy copper PCBs, so we are so confident that we can be your most reliable supplier in China. Welcome to contact us at any time for any questions or any queries about PCBs.

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Why Printed Circuit Boards are Important for Electronics?

Wednesday, December 7th, 2022

Printed Circuit Boards are the core of the electronics devices, and they exist in everywhere and be everything from your electronic equipment such as mobile phone, computers, so what are they? Let’s explore the secrets together and know why they become more common as technology advances.

What are Printed Circuit Boards?

A printed circuit board also known as PCB for short, is an electronic board for connecting metal circuits by mounting different electronic components in a device and have it do its functions.

PCB is made of fiberglass and laminate materials or a composite epoxy with conductive, it can be made to varies shapes and sizes depends on what applications it will be used for—some have many holes on it while some only have several pads or traces.

In most of devices, we can see there are many components or wires mounted or connected on the surface of PCB, which comes into two different pathways –surface mount and through-hole. Surface mount is a technology that can be abbreviated as SMT, it is a famous technical that mount electronic components (typically SMDs) attached on top of a pad by melted solder paste. Through-hole generally refers to components that have wires through the plated-through-holes that drilled into the circuit board. Both ways are commonly use, but currently with the fast development of the technology advance, surface mount is more popular than through-hole as it is more convenient for production.

What the Functions of Printed Circuit Boards?

The main functions of a PCB is to connect different components and achieve a communication between components and devices, that can be used for everywhere you can think of – Computer, phones, televisions, tablets, cameras, projectors, and so on….

For a simple example, a phone has a PCB that can connect screen, the buttons, cameras, and the circuits on the both sides. Without this board, those components wouldn’t be able to transmit signals and talk to each other and the phone would cease to function.

In addition, electronic equipment using printed board enable to avoid the error of manual wiring, and can realize the automatic insertion or installation of electronic components, automatic soldering, automatic detection by communicate with each other, to ensure the quality of electronic products, improve labor productivity, protect components from damaged, reduce costs, and easy to maintenance.

The advantages of Printed Circuit Boards

PCB performs a number of advantages in electronic industries, a most significant feature is they make products be smaller and more portable as its density circuits and components communication. The density circuits on PCB allows it take up much space for components so you can get a smaller product.

  • High density

Over the past decades, the high density of printed boards has been developed with the improvement of integrated circuits and the advancement of installation technology.

  • High reliability

Through a series of checks, tests and aging tests, the PCB can be guaranteed to work reliably for a long time (generally 20 years).

  • Designability

For various performance (electrical, physical, chemical, mechanical, etc.) requirements, can PCB be achieved to such requirements in short time and high efficiency according to design standard rules.

  • Maintainability

By means of standard PCB design rules, once the program or device failure, users fix the devices quickly.

  • Cooling abilities

Overheating is one of the biggest reasons of electronics failure, so by keeping them cool with a PCB, you can increase the lifetime of your product.

Types of Printed Circuit Boards

Best Technology provides different kinds of PCBs and PCBAs for our customers, for a quickly reviewing, we listing as below:

  • Rigid Printed Circuit Board (FR4-PCB)
  • Flex Printed Circuit Board (FPCB)
  • Rigid-Flex PCB
  • Metal Core Printed Circuit Board (MCPCB)
  • Ceramic Board
  • SinkPAD Board
  • Other special PCB such as heavy copper PCB, HDI PCB, RF PCB, and so forth
  • PCB assembly

In a word, with the development of electronics, it’s necessary to have a functional part like the PCB that can keep up with the demand. Next step, contact us if you have PCB demands.

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What is IPC standard for PCB?

Monday, June 28th, 2021

Do you know what is IPC standard for PCB?

IPC, it is a trade association whose goal is to standardize the assembly and production requirements of electronic devices and components.  It was established in 1957 as the Institute of Printed Circuits.  IPC has developed thousands of standards and specifications to regulate the electronics manufacturing industry

IPC standards are related to PCB design, production technology, electronic assembly, etc., in order to achieve high reliability, high quality, high performance, and meet user specifications.

For PCB manufacturing, do you know which IPC standards are commonly used?

multilayer pcb

Here I would like to share you some standards which we mainly use:

  1. 1. IPC-6011: General Performance Specification for Printed Boards
  2. 2. IPC-6012: Appraisal performance and specifications for Rigid printed boards
  3. 3. IPC-6013: Appraisal performance and specifications for Flexible printed boards
  4. 4. IPC-6016: Fixed performance and specification of HDI or printed circuit board of high density interconnection layer
  5. 5. IPC-SM-840: Appraisal and performance of permanent performance
  6. 6. IPC-HM-860: Multilayer Hybrid Circuit Specification
  7. 7. J-STD-003: Solderable test for printed boards
  8. 8. IPC-A-600F: Acceptance conditions for printed boards
  9. 9. IPC-A-61: Acceptability of electronic components
  10. IPC-4761: Design Guide for Protection of Printed Board Via Structures

One of the most widely used industry standards in the manufacturing of printed circuit boards is IPC-A-610C Acceptability of Electronic Assemblies and IPC-A-600 Acceptability of Printed Boards. This standard is used primarily for the incoming inspection of bare boards from a PCB fabricator.

In the IPC-A-610C document, electronic products are divided into level 1, level 2, and level 3. The higher the level, the stricter the quality inspection conditions. Here are how 3 levels divided:

Level 1 products: called general-purpose electronic products. Including consumer electronic products, certain computers and their peripherals, and products whose main purpose is to use functions.

Level 2 products: called dedicated service electronic products. Including communication equipment, complex industrial and commercial equipment and high-performance, long-life measuring instruments. Under normal use environment, this kind of product should not malfunction.

Level 3 products: called high-performance electronic products. Including high-reliability, long-life military and civilian equipment that can continue to operate. This kind of product must not allow any interruption failure during use, and at the same time, it is necessary to ensure the reliable startup and operation of the equipment in a harsh environment. Such as medical life-saving equipment and all military equipment systems.

resin filled production bpm20599

It is no problem for us to manufacture the PCB following the standard in IPC 6012 /6013 Class 2 and Class 3, as well as following to the standard listed above/

These acceptance conditions are the basis for the inspection of our company’s products, as well as the working standards of the employees at the production site, and also become an important part of the training of the employees for PCB production and assembly in our company.

Send us your PCB drawing, let’s help to make your PCB design into a real board.

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Interesting color matching – Silkscreen and Solder mask

Tuesday, March 23rd, 2021

In Best Technology, solder mask and silkscreen are available in a variety of colors. For example, common colors of solder mask are black, white, blue, green, red. Common silkscreen colors are black, white, yellow, red, blue. Generally according to the different needs of customers to use collocation, but sometimes if the color collocation is not appropriate will produce color difference.

The following is a list of common collocations that we recommend based on our experience for your future project design.

Solder maskRecommended Silkscreen
BlackWhite
WhiteBlack/Blue/Green/Red/Yellow
BlueWhite
GreenWhite
RedWhite

For the most part,the color of solder mask doesn’t have any effect on PCB’s

functionality.But if the color of the silk screen does not match properly,which may

Cause chromatic aberration(for example,a yellow silkscreen on a black solder mask,

The silkscreen visual may look green)or make reading the silk screen more difficult

To read(for example, a black silkscreen on a light black solder mask).The solder mask will also affect your ability to visually inspect the PCBs. Below are the solder mask comparison from the highest contrast to the lowest for your reference.

Green

Most customers will choose to use Green solder mask for their project since Green is easy on the eyes and allows for high contrast between traces, planes, and empty space on the PCB. Green solder mask has become an industry standard. High contrast allows technicians to most easily review for manufacturing defects.

green

Red

A Red solder mask will provide a bold and clean looking PCB, however the contrast between traces, planes, and empty space significantly lower than it is with a green solder mask. Magnification may be needed when inspecting fine traces on the board for defects with a Red mask. White silkscreen will be better than black silkscreen on a board with red solder mask.

red

 Blue

Blue solder masks have even lower contrast, and magnification becomes required when inspecting for manufacturing defects. These PCBs look visually pleasing and professional and are a good choice for fully-developed products that will not require trace visibility.

blue

Black

Black masks have almost no contrast between traces, planes and empty space. A Black mask will absorb heat, increasing the danger of overheating for sensitive components. Pay attention that in order to avoid the appearance of color difference as far as possible do not choose the silkscreen like yellow, green, red, or blue. White will be the better choice.

black

White

A white mask will be the hardest to clean, and also has the lowest contrast. If possible, we suggest that you avoid choosing white, especially in the prototyping stage. It’s the best choice to use white solder mask for LED board, following pictures for your reference.

whtite

If you have other questions about solder mask, welcome to contact us. (Email:sales@bestpcbs.com), we will prove you professional suggestions and solutions.

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What’s RT/duriod 5880?

Tuesday, December 1st, 2020

For PCB materials, you may have ever heard about many different kinds of materials such as the materials of FR4, Aluminum, Copper base and ceramic base.

But do you know what the duriod 5880 materials is?

Actually duriod 5880 is a kind of materials of the Rogers, it is the materials which is used for high frequency circuit board. RT 5880, which is famous for its low dielectric loss, low moisture absorption, and stable dielectric constant. The PCB made of duriod 5880 can be widely used in airborne and ground-based radar systems, millimeter wave applications, and space satellite transceivers.
Different with other kinds materials, the color of the RT 5880 materials is black.

Why this material can be used in such high end field? Let’s see below to know more information.

Excellent dielectric properties:
RT/duroid 5870/5880, as a new generation of high-frequency laminate, is made of polytetrafluoroethylene composite material (PTFE). At the same time, glass microfibers are randomly distributed in the material, which provides the greatest strength during the production and application of the circuit board.

High-frequency circuit design has strict requirements on the dielectric constant of the printed circuit board. RT/duroid 5880 has an ultra-low dielectric constant and remains the same in a very wide operating frequency range.

At 10GHz operating frequency, the measured dielectric constant is only 2.33/2.2, which is significantly lower than similar materials on the market. Therefore, from the perspective of performance parameters and production costs, the board is more suitable for high-frequency application design than similar products.

At the same time, under the same standard (f=10GHz), and the dielectric loss of the RT5880 is only 0.0012/0.0009. The extremely low dielectric loss makes it very suitable for high-frequency and the field of wide-band applications which requiring minimal dispersion and low loss.

In addition, the extremely low moisture absorption rate makes it an ideal choice for applications in high humidity environments. The moisture absorption rate of RT/duroid 5880 is only 0.02%, so it can meet the strict requirements of mechanical reliability and electrical stability in the complex microwave structure design, and it is also suitable for applications in high humidity environments.

With the continuous improvement of the operating frequency of high-frequency circuits, the requirements for the dielectric constant and dielectric loss of the circuit board are becoming more and more stringent. The excellent performance of RT/duroid 5880 in these two aspects can significantly improve the design of high-frequency circuits. Definity, improve circuit performance.

Easy to process and install
In this high-frequency design, in order to meet the requirements of electromagnetic shielding and compact design, printed circuit boards are often installed in various irregularly shaped cavity structures. Therefore, the PCB board must be designed in different shapes and suitable for production and Installation.

For RT/duroid 5880 laminate, which is easy to cut, trim and good for PCB manufacturing.

At the same time, it can resist all the solutions and chemical agents used in the process of etching and plating through holes, and it has a good performance of the cold and heat resistance.

The composite material RT/duroid 5880 can be covered with a laminated copper foil for some key electrical applications, and brass plates or copper can also be used as required.
Usually laminates of the RT/Duriod 5880, it can make double-sided copper clad with thicknesses ranging from 1/2 oz. to 2 oz./ft2 (8.5~70 μm) to meet most custome’s requirements for the thickness of copper foil.

Our company has focus on the PCB fabricationi for more than 15 years, we can make PCB with Rogers PCB with RT/Duriod 5880, as well as RO4003C and RO4350B with different thickness.
If you are interesting to know more and your PCB also want to made of RT/Duriod 5880, please feel freely to contact us for more information related.

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