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Advanced Multilayer PCB & Rigid Flex PCB manufacturer in China

We have more than 20 years of experience in the circuit board field


Heavy copper PCB – 4 layers board applied to new energy vehicles

Number of layers:4L

Type:Thick Copper PCB

Material requirements:TG170, CTI>600V

Laminated structure:FR4+PP



Copper thickness:5/3/3/5 oz

Minimum aperture:0.5mm

Minimum line width/line spacing:10/10 mil

Aspect ratio:4:1

Solder mask color:Green

Surface treatment:HASL

Application:Communication base station motherboard

Manufacturing difficulties:High multi-layer structure

  • Product Detail
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  • Packing & Delivery

2 layers heavy copper circuit board plated with a copper thickness of 8oz. It is applied to the power supply system of new energy vehicles. RCY’s automotive electronics PCB accounted for more than 40% of the total turnover.

1.Production process:

Cutting → first drilling → outer layer→ outer etching → outer QC inspection → outer AOI inspection → immersion Copper → panel plating → Resin plug hole → Secondary drilling → immersion copper → outer layer → outer layer etching → outer layer QC inspection → outer layer AOI → solder mask pretreatment → solder mask → characters → immersion gold → routing → flying probe test → FQC → packaging

2. Manufacturing difficulties

Because of the large copper thickness, the heavy copper board brings a series of processing difficulties to PCB processing, such as the need for multiple etchings, insufficient filling of the pressing, cracking of the inner layer of the drilled hole, and difficulty in guaranteeing the quality of the hole wall.

a.Difficulties in etching

As the copper thickness increases, due to the increasing difficulty of potion exchange, the amount of side erosion measured will become larger and larger; in order to reduce the amount of side erosion caused by potion exchange as much as possible, multiple rapid etchings are required. The method solves the problem. As the amount of side erosion increases, it is necessary to increase the etching compensation coefficient to compensate for the side erosion.

b.Difficulties in lamination

With the increase of copper thickness, the line gap is deeper. In the case of the same copper residual rate, the required amount of resin filling needs to be increased. You need to use multiple prepregs to meet the filling problem; because you need to use resin to maximize The filling line gap and other parts, the glue content is high, and the prepreg with good resin fluidity is the first choice for heavy copper boards. The commonly used prepregs are 1080 and 106. In the inner layer design, copper points and copper blocks are laid in the copper-free area or the final milled area to increase the residual copper rate and reduce the pressure of filling.

The increase in the amount of prepreg used will increase the risk of sliding, and the method of adding rivets can be used to strengthen the degree of fixation between the core boards. Under the trend of increasing copper thickness, resins have also begun to fill the blank areas between patterns. Since the total copper thickness of heavy copper boards is generally above 205.8um (6 oz), the CTE matching between the materials is particularly important (for example, the CTE of copper is 0.0017% (17ppm), and the glass fiber cloth is 0.0006%-0.0007% (6ppm). -7ppm), the resin is 0.02%]. Therefore, in the PCB processing process, the choice of fillers, low CTE, and high Td boards is the basis for ensuring the quality of heavy copper (power) boards.

As the copper is thicker than the board thickness, more heat is required for lamination. The actual heating rate will be slower, and the actual duration of the high-temperature section will be shorter, which will result in insufficient resin curing of the prepreg, which will affect the reliability of the board; therefore, it is necessary to increase the duration of the high-temperature section of the lamination to ensure The curing effect of the prepreg. For example, insufficient curing of the prepreg will result in a large amount of glue removal relative to the prepreg of the core board, forming a stepped shape, and then the hole copper will be broken due to stress.

c.Difficulties in drilling

As the copper thickness increases, the thickness of the heavy copper board also increases. Heavy copper boards usually have a thickness of more than 2.0mm. Due to the thicker board thickness and thicker copper thickness during drilling, it is more difficult to manufacture. In this regard, new tools are used to reduce the service life of the drill, and segmented drilling has become an effective solution for drilling heavy copper boards. In addition, the optimization of drilling-related parameters such as feed speed and retreat speed also have a greater impact on the quality of the hole.

The problem of milling target holes. When drilling, the energy of X-RAY gradually attenuates with the increase of copper thickness, and its penetrating ability will reach the upper limit. Therefore, for heavy copper PCBs, the first board cannot be confirmed when drilling. In this regard, you can set offset confirmation targets at different positions on the edge of the board, and mill out the offset confirmation target line on the copper foil according to the target position on the data when cutting the material. When lamination, the target hole and inner hole on the copper foil are milled out. The layer target hole corresponds to the production.

The problem of cracking of inner heavy copper pads (mainly for large holes above 2.5mm). There is more and more need for heavy copper boards, and the inner pads are getting smaller and smaller, and the problem of pad cracks often occurs during PCB drilling.

There is little room for improvement in this type of problem material. The traditional improvement method is to increase the pad, increase the peel strength of the material, and reduce the drilling speed of the drill.

Analyze the PCB processing design and technology, and propose an improvement plan: copper out processing (that is, when the inner layer of the pad is etched, the concentric circles smaller than the hole diameter are etched) to reduce the pulling force of the drilled copper.

The first drill will get a pilot hole smaller than the hole diameter of 1.0mm and then performs normal drilling (that is, perform secondary drilling) to solve the problem of cracking of the inner heavy copper pad.

3. Application areas:

This heavy copper PCB is used in the field of new energy vehicles. The heavy copper PCB is a power supply board for vehicles. It can carry large currents, with good heat dissipation capabilities, and can provide continuous power for new energy vehicles.

With the rapid promotion of new energy vehicles, heavy copper boards will increasingly play an important role.

But at the same time, the increasingly high requirements of customers have also brought great challenges to PCB manufacturers. We believe that with the advancement of materials, we and other PCB manufacturers continue to encounter problems during the production process, and solve the problems, many problems will be solved.


RCY PCB is a professional PCB manufacturer with more than 20 years of professional experience leading process capability in the field of Rigid PCBFlex PCBRigid-flex PCB, etc. If you have any PCB/PCBA demands, feel free to contact us. Email: Sales@szrcypcb.com

Rich industry experience

RCY was founded in 2000 and hasmore than 20 years of experience in circuit board manufacturing. Our products are widely recognized by customers, and we have accumulated rich industry experience. ThePCB, rigid-flex PCB and flex PCB are used in automotive electronics, security monitoring, industrial control, current sources, communication equipment, smart wearables, medical equipment, aerospace and other fields.

Leading process capability

Reliable quality

The project strictly implements ISO9001, IATF16949, UL and other internationally certified management standards, builds and perfects a quality monitoring and prevention system to ensure the stability of product quality.

Delivery capability

We have a flexible delivery time, in order to help our customers to deliver quickly and win market opportunities.

The lead time for conventional PCB samples is 7 to 12 days, while the lead time for mass production is 12 to 20 days. For special PCBs, we will provide the corresponding delivery date according to the difficulty.

Of course, the specific delivery date depends on the specific product.

Advantage production equipment

RCY has invested more than 50 million US dollars in equipment. Except for a few special processes, all manufacturing processes are completed in-production, which further improves product stability.

Competitive price

Providing customers with competitive prices is an important part of helping customers succeed. However, we firmly believe that competitive prices are not obtained by sacrificing product quality. We reduce production costs by optimizing product design, introducing more advanced and automated equipment, reducing the scrap rate, and reaching closer cooperation with the supply chain.

Q: Who is RCY?
A:RCY (RenChuangYi) is a professional circuit board factory established in 2000. Currently, there are more than 400 employees, and the circuit board production capacity is 35,000 square meters per month. We have honored a high-tech enterprise in China, and one of the top 100 circuit board manufacturers in China.

Q:What circuit board is your advantage?
A: RCY spares no efforts to provide customers with high-quality, high-precision circuit boards. We can undertake orders from samples, small batches, medium batches to large batches. We can fabricate 2 to 36 layers of PCB, HDI boards, flexible PCB, rigid-flex PCB, high-frequencyand high-speed boards, etc.

Q:Is your circuit board quality reliable?
A: RCY has passed ISO9001, IS014001, IATF16949, UL, CUL, and CQC certifications. We have a complete quality control system. All products shipped are in line with IPC-2 and above standards. Our product quality is stable and trustworthy.

Q: Do your products meet the environmental protection requirements of ROSH and REACH?
A:Yes, all the products we produce are in line with ROSH2.0 and REACH2.0 standards. At the same time, we can also provide halogen-free circuit boards to meet customers’ requirements.

Q: How can I ask for a quotation?
A:Please provide your Gerber files and board-making requirements, and send them to our official Email address: sales@szrcypcb.com. For regular PCBs, we will reply within 8 hours. The quotation time for special PCBs may be extended.

Q: If the business conditions are confirmed to be no problem, how can I place an order for you?
A: Firstly, you need to provide the business license of your company, the delivery address and the billing address (we will also send our information back for your record).
Secondly, youneed to place the order and send it to our sales Email, which will be sealed by both parties.After the order is confirmed, we will provide EQ to you and ask for confirmation.
In the next step, we will place the order in our system, and the production will be arranged.
Lastly, the production is finished, after which the information needs to be verified and the circuit boards will be shipped to your delivery address.

Q: How long is your delivery time in general?
A: Sample delivery time: 7-10 days for hard boards; 10-12 days for soft boards; 16-20 days for flexible and hard boards; special circuit boards, according to the difficulty of individual response to the delivery date.
Batch delivery time: 12-20 days for hard boards; 15-20 days for soft boards; 20-30 days for flexible and hard boards; special circuit boards, according to the difficulty of the delivery.

Q: What are your shipping methods?
A: a. Express delivery: the companies we work with are UPS, FedEx, DHL, and SF.
b. Shipping method: FCA HK and FOB HK

Q: If there is a quality problem, how to solve it?
A: Please contact us timely if there is a quality problem. We will have dedicated specialists to analyze the problems that arise. If it is true that the problem is caused by the abnormal quality of the circuit board, we will assist the customer to deal with it and bear the corresponding loss.

Q: Regarding product privacy issues?
A: We respect the privacy of all customers. We promise that we will never share customers’ personal or product information with any third party without the customer’s permission.

All of our fiber optic cable package are with export wooden drum. Indoor FTTH cable’s wooden dimension is 50x50x32cm, delivery length 3km/drum, Outdoor fiber optic cable’s wooden dimension is 110cm*110cm*70cm, 0.85CBM, can be load about 33 drums for a 20GP.Also accept custom cable drum from customers. welcome to contact us!

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