Why choose Heavy Copper PCB for your High Current Project?

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.

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.

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.

Tags: heavy copper pcb
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Can I Design Via Holes in Thick Film Ceramic Boards?

April 18th, 2023

May some engineers or designers who be interested in thick film ceramic circuit are curious about can thick film ceramic boards design with via holes like FR4 PCB? Herein, we will explore the feasibility of using thick film ceramic boards for via holes, including the materials and processes involved, as well as the advantages of this approach.

What is thick film ceramic board?

The “Thick Film” refers to the thickness of conductor layer on a Ceramic PCB. Normally the thickness will be at least 10um, around 10~13um, which is thicker than spurting technology in Thin Film Ceramic PCB. And of course thickness is less than DCB Ceramic board or FR4 board.

Thick film ceramic circuit enables to put resistor, electric capacitor, conductor, semi-conductor, and interchangeable conductor on ceramic board, after manufacturing steps of printing and high temperature sintering. The more important thing is by using thick film technology, we can make all the resistors with the same value, or different value for different resistor on the same board.

Materials and processes for via holes

In general, thick film ceramic circuit is not suitable for designing via holes. Because the characteristics of thick film ceramic board mainly depends on the insulation properties of its ceramic substrate, rather than conductive properties. The conductivity of thick film ceramic plate is not good than Metal Core PCB, or even we can say it has a very poor conductivity, usually can’t meet the requirements of the via hole.

But, designing via holes in thick film ceramics is available in Best Technology. Generally speaking, the fabrication of via holes in thick film ceramic boards typically involves several key materials and processes.

From the designer’s perspective, a conductive material is used to create a continuous conductive path from one side of the ceramic board to the other. Common conductive materials include gold paste, silver paste, and copper paste. These materials are usually screen printed onto the ceramic board in the desired pattern, and then fired at high temperatures to achieve sintering and form a conductive layer.

Once the conductive layer is formed, the via holes are created by drilling or punching small holes through the ceramic board at the desired locations. These holes are then filled with a conductive material, such as silver paste or copper paste, to establish electrical connections between the different layers of the circuit.

Finally, the via holes are fired again at high temperatures to achieve sintering and ensure good adhesion and electrical performance.

Advantages of Via Holes in Thick Film Ceramic Boards

These via holes offer several advantages in the design and fabrication of thick film ceramic boards, including as following:

Electrical connectivity

Via holes provide electrical connectivity between different layers of a thick film ceramic board. They allow for the interconnection of different circuitry or conductive layers, enabling the flow of electrical signals or power between different parts of the board. This allows for complex and multi-layered circuit designs, which can be highly beneficial in applications that require intricate circuitry or high-density interconnects.

Space-saving

Via holes can provide a means of vertical interconnection, allowing for more efficient use of board real estate. Instead of routing traces or conductors on the surface of the board, which can take up valuable space, via holes can be used to route connections through the board, freeing up surface area for other components or functions. This is especially advantageous in compact or miniaturized electronic devices where space is limited.

Thermal management

Via holes can aid in thermal management in thick film ceramics. They can be used to transfer heat from one layer of the board to another, helping to dissipate heat generated by components or circuits. This can be particularly important in high-power or high-heat applications, where efficient thermal management is crucial for preventing overheating and ensuring reliable performance.

Mechanical stability

Via holes provide additional support and reinforcement to the board, reducing the risk of warping, bending, or cracking. Via holes can also help improve the overall mechanical integrity of the board by reducing stress concentration points and enhancing its structural rigidity.

Design flexibility

Via holes offer design flexibility in thick film ceramic boards. They can be designed and placed according to the specific requirements of the circuit or system, allowing for customized and optimized designs. Via holes can be used to route traces, create vias for component mounting, or provide grounding or shielding, among other functionalities. This flexibility in design allows for more efficient and effective circuit layouts, which can lead to improved performance and reliability.

As previously mentioned, designing via holes in thick film ceramic boards offers various benefits. However, when it comes to choosing the appropriate paste for via holes, silver paste is often recommended to our customers. But why is that? Can I use gold or copper? In our upcoming article, we will delve into the reasons behind this recommendation and provide you with valuable insights. Stay tuned to uncover the answers!

Tags: ceramic PCB
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“Eight” Safety Spacings You Must Know In PCB Design

December 7th, 2022

There are many places in the Printed Circuit Board Design that need to consider the safety spacing, here we summarized Eight Safety Spacings in total to show you what spacing we should pay attention to when designing, they can be separated into two categories, one is Electrical-Related Safety Spacing, and another is Non-Electrical-Related Safety Spacing.

Electrical-Related Safety Spacings

Wire Spacing

As far as the processing capability of the mainstream PCB manufacturer is concerned, the spacing between the wires shall not be less than 0.075mm. The minimum line distance refers to line to line, line to pad space. From a production perspective, the larger the better, and the more common wire spacing is 0.25mm by far.

Diameter and Width of Pad

From the processing capability of mainstream PCB manufacturers, the minimum diameter shall not less than 0.15mm if the holes on pad requires mechanically drilled. If used laser drilling, then hole diameter must greater or equal than 0.10mm. At the same time, the tolerance of hole diameters varies slightly according to different substrates. Generally, it can be controlled within 0.05mm, and the minimum width of the pad should not be less than 0.2mm.

Spacing between Pad to Pad

The spacing between pads must be at least 0.2mm as far as the processing capacity of mainstream PCB manufacturers concerned.

Copper and Edge of the Board Spacing

The spacing between electronic copper and edge of the board should be no less than 0.30mm, and it can be set spacing rule on the “Design – Rules – Board outline” page.

If it requires a larger area of copper, it is generally needs to set 0.5mm as a retraction spacing from the edge of board. In the PCB design and manufacturing industries, engineers often shrink the large area of copper coating to the edge of the board by 20mil for mechanical considerations of the finished circuit board, or to avoid the occurrence of curling or electrical short circuit caused by the exposure of copper on the edge of the board, rather than coating whole copper to the edge of the board.

There are many methods to handle such shrink problems, such as drawing a keepout layer and then set a distance between copper and the keepout. As a professional PCB manufacturer that have rich experience over 16years, there is a much easy way to set different safety spacings for copper objects. For example, the safety spacing of the whole board set as 0.25mm, then we can set copper to 0.5mm, which can achieve a shrink distance of 0.5mm, and the dead copper that may cause in some devices also can be removed as well.

Non-Electrical-Related Safety Spacing

Width, Height and Spacing of Legends

We can’t make any changes during the processing of text legend film, except that the line width of legend with D-CODE less than 0.22mm (8.66mil) is enlarged to 0.22mm, that is, the line width of legends L=0.22mm (8.66mil).

The width of the whole charact legends W=1.0mm, the height of the whole legends H=1.2mm, the spacing between the legends D=0.2mm. When the text is less than the above standard, the text legends after printing will be blurred.

Spacing between Via to Via

The spacing between vias to vias is preferably not less than 8mil.

Spacing between Legend to Pad

Legends/Silkscreens are not allowed on the pads, otherwise, the covered area can’t be tinned and which will affect the assembly process finally. Generally, manufacturer requires a 8mil space to convenient for silkscreen printing, but if your PCB is small and limited in area, it is barely acceptable to leave a 4 mil safety space.

If some legends accidentally over the pads in your design, Best Technology will remove or move to another area when get your approval to ensure good tinned.

Of course, design on a case-by-case situation. Sometimes the screen printing is deliberately close to the pad, because when the two pads are very close, the screen printing in middle can effectively prevent the short circuit of the solder connection during soldering, and this is another case.

Mechanical 3D height and Horizontal Spacing

When mounting the components on the PCB surface, it is necessary to consider whether there will be conflicts with other mechanical structures in horizontal direction and spatial height. Therefore, in the PCB design, the compatibility between components, finished products and product outer house and spatial structure should be fully considered, and the safety spacing should be reserved for each target object to ensure there is no conflicts occur in space.

In summary, there are many data and key points should be pay highly attention to while in PCB designing, Best Technology manufactures varies of good quality PCBs for our customers, so please do not hesitate to contact us when you have PCB design, we can help to evaluate it freely for you.

Tags: FR4 PCB
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A Guideline about Legend on Printed Circuit Board

November 29th, 2022

Printed circuit board is used to power up the electronic devices, and the legend on its surface been known as legend text or silkscreen text to be aim at providing vital information to electronic manufacturers or end users. This post is a guideline to help you understand what information we can gain from those legends and what we need to pay attention to when design them.

A brief introduction about PCB legend

Though a printed circuit board doesn’t require any legend/text to function technically, the text provides key information to end users to test, assemble and troubleshoot, and generally we can obtain following information from the legends:

Branding information

This includes manufacturer’s information, serial numbers, date code and other information, which prevents the copying of design.

Part number provided

Part numbers are added on the circuit boards to enable replacement or design evolution whenever needed.

Version of product

Sometimes versions were updated, and the legend is added on the circuits to identify the specific version and backtrack the date.

Reference of components indicators

This may feature components information such as indicators, orientations and other information.

Safety Precautions

These are warning signals that are added to protect users from electric shocks. A few examples of these may include grounding, high voltage, and so on.

Circuit Identification

Users and designers can identify circuit names from legends to understand testing points, ground points, component interconnect, so forth.

Polarity indicator for certain components

Some components such as diodes, LED chips, electrolytic capacitors require to a distinguish of polarity when assembly, text legends help to indicate the right polarity to ensure assembled correctly and perform functionality when reach to consumers.

Authentication indication

Silkscreen text shows the boards are authenticated or conforms to certain security certification, such as RoHS, 94V-0, UL…

Test points and troubleshooting assistants

Help to correctly perform testing including resistance measurement, voltage measurement, function testing and so forth. In addition, text legend enables to troubleshoot while issues or debugs happened and repair is required.

Component outlines indicating where components should go

Legends provides a great help during assembly process, it helps the operator quickly find where each component should be, so it is recommended to add text legends when PCB need to be assembled.

General Parameters for PCB Legend in Best Technology

To understand the capabilities of legend printing of Best Technology, here we listing some general parameters for your reference:

Legend colors can be white, black, green, yellow or other colors depend on customer’s preferences.
Legend line width is range from 5mil to 7mil
Text height can set at 30mil
Maximum text width can be 17mil
Printing methods are screen printing, direct legend printing and Liquid photo imaging. (Direct legend printing is commonly used by far.)

Important factors need to be considered during designing

Although legends are easy to be printed, there are still some key points need to pay highly attention when you are designing.

Legend orientation: To maintain a good reading appearance for user, please make sure all legends throughout the board have a same orientation.
Choose a standard color and shapes for marking, this is a most economy way to save cost.
Avoid overlapping: Overlapping is one of the most common problems that manufacturer faced. Legend always be related to PCB layout, and components reference will be also designated when circuit board layout finished. So if the legend was overlapped, it must be moved to another place and that may cause component reference was located in a wrong position, so it is always recommend to double check all the legends, to make sure they are clear and in the correct position when the whole board layout was completed.

Do not place the silkscreen text on all four directions, this will lead to confusions when the circuit board is undergoing repair.

Leave a few mils space for some common potential printing errors, this will help manufacturer to reduce the possibility of errors.

Every PCB manufacturer has its unique style and pattern when it comes to legend printing, so working files confirmation plays an important role before circuit fabrication, Best Technology gives a great respect to the original files to our customers, we won’t start production until get approval of working files from customers, so please do not worry about it if you have such concerns. In addition, as a professional printed circuit board manufacturer in Asia, we are confident that we can provide you with high quality PCB, welcome to contact us if you have PCB needs.

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Why most of PCB boards are green?

August 24th, 2021

You may have found such a situation, most of the PCB boards are with green colors, while other colors are relatively rare to see, do you know why?

As we know that the Printed Circuits Board consists of Solder Mask Layer, Silk screen layer, solder PAD, Copper traces, surface finishing and other parts, etc.

Among them, the solder mask refers to the part of the PCB that is covered by oil. Since most PCB boards use green oil, the part of the green oil that can be seen on the board surface is the solder mask, which play an important role during the reflow soldering process.

Then why are most of the PCB boards green? The main reasons are as follows:

Green is less irritating to the eyes. We all know that green is good for the eyes and can resists fatigue. So when the PCB board with green solder mask, relative production and maintenance personnel are not prone to eye fatigue when staring at the PCB board for a long time, and it is less harmful to the eyes.

2. Cost for Green oil is lower. Since green is the mainstream in the production process, the purchase of natural green oil will be larger, and the purchase cost of green solder mask will be lower than other colors. At the same time, using the same color oil in mass production can also reduce the replacement cost.

When the board works on the SMT soldering process, it needs to go through the process from Tinning, post soldering and final AOI inspection. These processes all need to be optically positioned and calibrated. The green background color is better for the recognition of the instrument.

Okay, now, do you understand why most of PCB boards are with green colors?

Though we know green is the most common one, but other colors such as red, yellow, blue, purple, black or some other colors are okay for us to make.

If you have PCB board with a special color want to make, please contact us and we will try best effort to meet your request.

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