In the highly competitive field of PCB manufacturing, with two decades of in – depth experience, we have a profound understanding of various circuit boards. Today, we’d like to introduce you to Heavy Copper PCB, which plays an irreplaceable role in high – power and high – current electronic devices. A Heavy Copper PCB refers to a printed circuit board with a copper foil thickness of 3 ounces (about 105 microns) or more. By thickening the copper layer, it achieves excellent current – carrying and heat – dissipation capabilities, and is widely used in key areas such as new energy vehicles, industrial power supplies, and aerospace.

What is heavy copper PCB?

What exactly is a Heavy Copper PCB? Simply put, it’s like the “strongman” in electronic devices. When facing high currents, ordinary PCBs often struggle, much like a small water pipe that can’t handle a sudden large flow of water, leading to problems such as overheating and ablation. However, Heavy Copper PCBs are different. Take new energy vehicles as an example. The motor controller of a new energy vehicle can generate currents of hundreds of amperes during startup. Ordinary PCBs can’t meet this demand at all, but Heavy Copper PCBs, with their thick copper layers, can steadily carry high currents, ensuring the stable operation of the motor and a smooth ride for the vehicle.

Heavy Copper PCB definition

The core of the Heavy Copper PCB definition lies in “thick copper”. It breaks through the limitations of the copper foil thickness of conventional PCBs and thickens the copper foil through special processes. This is similar to electrical wires – thin wires can only transmit small currents, while thickened cables are capable of handling large – current transmission. Moreover, its thick copper layer also has excellent heat – dissipation functions, just like a powerful radiator equipped for the circuit board. For electronic devices with strict requirements for current and power, it is an essential key component.

Heavy Copper PCB stackup?

Designing the stackup of a Heavy Copper PCB is like building a complex and sturdy building. The selection of the thickness of the thick copper conductive layer, the most crucial part, needs to be based on the actual current demand. For example, in charging pile projects, considering the high currents during charging, we usually use 10 – ounce copper foil. Coupled with highly thermally conductive aluminum – based or ceramic substrates, heat can be quickly conducted away. The large – area ground/power layers not only reduce impedance but also form efficient heat – dissipation channels. Every time our engineers design, they will combine specific application scenarios, adjust and optimize repeatedly to ensure that the stackup structure achieves the best performance.

Heavy Copper PCB Manufacturers

As an established manufacturer with 20 years of experience in the Heavy Copper PCB manufacturing field, we have witnessed the entire process of the industry’s development from its infancy to prosperity. From the difficult exploration in the early days when technology was not mature to the ability to provide comprehensive high – quality services to customers today, every step reflects the hard work and dedication of our team.

Heavy Copper PCB design

Our design team consists of more than 20 experienced “veterans”, each with nearly 20 years of design experience. The design process is far more than just drawing a circuit diagram. We conduct Power Integrity (PI) analysis, which is like a comprehensive “physical examination” for the circuit board, ensuring voltage stability under high currents. We also use thermal simulation technology to predict heat distribution in advance and plan heat – dissipation paths. In addition, our free Design for Manufacturability (DFM) inspection once helped a customer discover that the drilling process for the thick copper layer in their design was difficult to implement. After timely adjustments, a lot of time and costs were saved.

Heavy Copper PCB prototyping

We understand how important time is to our customers, so we’ve set up an urgent prototyping channel. The fastest delivery time for samples is 24 hours. Advanced processes such as laser drilling and electroplating via filling are used during prototyping to ensure reliable connections between thick copper layers. We can also fully meet customers’ special material requirements, such as Rogers and DuPont materials. Once, for a scientific research project, we coordinated resources overnight to deliver samples of Heavy Copper PCBs made of special materials on time, winning high praise from the customer.

Mass production

Our factory covers an area of 8,000 square meters, with complete equipment and standardized management. The monthly production capacity can reach 260,000 square feet (about 28,900 square meters). We have obtained multiple international certifications, including ISO13085, IATF16949, etc. Each batch of products undergoes strict quality inspections from raw materials to the finished product to ensure reliable quality.

Heavy Copper PCB assembly

With more than 10 SMT production lines operating simultaneously, even tiny components like 01005 can be precisely mounted. We also provide some passive components for free. From pasting, soldering to the final full – process inspection, including X – RAY, AOI, and ICT functional tests, we offer customers worry – free Turnkey services.

Why Choose Us

On-Time Delivery

On – time delivery is our solemn commitment to customers. Over the past 20 years, through cooperation with numerous customers, we deeply understand the importance of project schedules. Therefore, we have established a complete production management system, strictly controlling every time node from raw material procurement to finished product delivery. Customers can check the production progress of their orders in real – time through the online WIP system. Our on – time delivery rate is as high as 98%. For an urgent order, our entire team worked overtime and optimized the production process to deliver the goods to the customer one day ahead of schedule, winning the customer’s trust.

Turnkey Service

Our Turnkey service is designed to save customers time and effort. We cover everything from design, prototyping to production and assembly. Once a project starts, a dedicated project manager will follow up throughout the process, responding to customers’ technical questions and other needs within 24 hours. We also provide detailed DFM/DFA reports to help customers optimize their products and shorten the project cycle. There was a customer who simply put forward a requirement, and we took care of everything. Eventually, the product was successfully launched, and this customer even introduced many new customers to us.

Competitive Pricing

To help customers save costs, we constantly optimize production processes and negotiate with suppliers to reduce raw material prices. For example, the price of our 10 – ounce copper – thick PCB is 18% lower than the industry average, while maintaining uncompromised quality, attracting many customers to become our long – term partners.

Quality Assurance

Quality is our top priority. When raw materials enter the factory, each batch of copper foil undergoes ductility testing, and the substrate is tested for glass transition temperature (Tg value). Any unqualified materials are rejected. During the production process, 7 quality inspection procedures are set up, with dedicated personnel responsible for each link. Before the finished product leaves the factory, 100% electrical testing is carried out, and the defect rate is controlled below 0.3%. Once we find any product problems, we will not hesitate to rework to ensure quality and reputation.

What are the advantages of Heavy Copper PCB

Strong Current – Carrying Capacity

One of the most remarkable advantages of Heavy Copper PCBs is their strong current – carrying capacity. A 10 – ounce copper foil can carry more than 50A of current under a 10℃ temperature rise, which is more than 5 times that of a 1 – ounce copper foil. In industrial power supply equipment, it can easily handle high – current transmission, ensuring stable equipment operation.

Efficient Heat – Dissipation Performance

Its thick copper layer has excellent heat – dissipation effects, just like a “mini air conditioner” for electronic components. In the battery management system of new energy vehicles, it can effectively reduce the temperature of the battery pack and extend battery life. Some customers have reported an increase in battery range after using our Heavy Copper PCBs.

High Reliability

Through actual testing, during 2000 thermal cycle tests (- 40℃ – 125℃), the failure probability of solder joints of Heavy Copper PCBs is 80% lower than that of ordinary PCBs. In the aerospace field, which has extremely high requirements for reliability, it can operate stably in extreme environments.

How to choose pcb copper thickness

Choosing the copper thickness of a PCB requires considering multiple factors:

Current – Carrying Requirements

According to the IPC – 2152 standard, a 1 – ounce copper foil can carry 1A of current per 1mm of line width under a 10℃ temperature rise. You can calculate the required copper foil thickness based on this, but the actual situation still needs specific analysis.

Heat – Dissipation Requirements

For every additional 1 ounce of copper thickness, the thermal conductivity increases by approximately 12%. For high – power devices such as IGBTs, to ensure good heat dissipation, it is recommended to choose a copper thickness of 5 ounces or more.

Mechanical Strength

Although thick copper layers have excellent performance, they will make the PCB harder. In scenarios where bending is required, the bending stress of the board needs to be considered. Generally, a copper thickness of less than 10 ounces is more suitable for conventional applications, but the specific choice still depends on the design requirements.

Heavy Copper PCB manufacturing process

Every step in the manufacturing process of Heavy Copper PCBs is crucial

Step 1: Substrate Pretreatment
First, the substrate is roughened to enhance the adhesion between the copper foil and the substrate. At the same time, a substrate with a high glass transition temperature (Tg≥170℃) is selected to prevent deformation of the substrate during subsequent high – temperature electroplating, which could affect dimensional accuracy.

Step 2: Pattern Transfer
The Laser – Direct – Imaging (LDI) technology is used to control the line width accuracy within ±5μm. To prevent excessive corrosion of the copper foil during electroplating, the dry film thickness is increased to 50μm to ensure accurate circuit patterns.

Step 3: Thickening Electroplating
This is a key step! A high – acid and low – copper electroplating solution is used, and the current density is increased to 30ASF. The electroplating time is 3 – 5 times that of ordinary PCBs to plate a thick copper layer of 10 ounces or more and ensure uniform copper layer thickness.

Step 4: Drilling and Via Metallization
Special hard alloy drills are used, and the rotational speed is reduced to 20,000rpm to avoid drill breakage. After drilling, secondary electroplating via filling is carried out to ensure that the uniformity of the copper thickness inside the via is controlled within ±10%, which requires extremely high – level craftsmanship.

Step 5: Surface Treatment
Whether it is Electroless Nickel Immersion Gold (ENIG), controlling the thickness to ≥3μm to improve solderability, or Hot Air Solder Leveling (HASL), controlling the temperature to ≤260℃ to prevent oxidation of the thick copper, every detail is related to the quality and performance of the PCB.

What problems can Heavy Copper PCB solve?

High – Current Heating Problem
In industrial power supply equipment, ordinary PCBs often suffer from severe overheating or even burnout due to high currents. Our Heavy Copper PCB can reduce the temperature rise by 60% compared with 1 – ounce copper thickness, effectively solving the heating problem and ensuring the safe operation of the equipment.

Uneven Heat – Dissipation Problem
In IGBT modules, poor heat dissipation of ordinary PCBs can lead to a decline in module performance. The thick copper layer of Heavy Copper PCBs, serving as a heat – dissipation plane, can reduce the temperature difference of the module hotspots from 30℃ to within 10℃, improving equipment stability.

Unstable Impedance Problem
In automotive motor controllers, voltage fluctuations can affect motor performance. The large – area thick copper power layer of Heavy Copper PCBs can reduce loop impedance and control voltage fluctuations within ≤1%, making the motor run more smoothly.

What is the difference between Heavy Copper PCB and FR4?

Comparison Dimension	Heavy Copper PCB	FR – 4 PCB
Copper Foil Thickness	≥3oz (usually 3 – 20oz)	0.5 – 2oz
Current – Carrying Capacity	10oz copper can carry 50A + current	1oz copper can only carry about 10A current
Heat – Dissipation Performance	Thermal conductivity increases with copper thickness	Thermal conductivity is about 0.22W/m·K
Application Scenarios	High – power and high – current devices	Consumer electronics, low – power scenarios
Manufacturing Process	Requires special thickening electroplating and drilling processes	Conventional processes are sufficient
Cost	30% – 80% higher than FR – 4	Lower cost

Heavy Copper PCB application

New Energy Vehicle Field
From motor controllers, battery management systems to on – board chargers, Heavy Copper PCBs are essential. It carries high currents to drive the motor in the motor controller, balances the current of the battery pack in the battery management system, and reduces heat loss and improves charging efficiency in the on – board charger. Our products have been recognized by many new energy vehicle manufacturers.

Industrial Equipment
When industrial equipment such as servo drives, solar inverters, and UPS uninterruptible power supplies operate at high power, Heavy Copper PCBs can stably transmit electricity, reduce failures, and improve equipment operation speed and accuracy.

Medical Equipment
In medical equipment such as magnetic resonance imaging (MRI) devices, high – frequency electric knives, and medical power supplies, Heavy Copper PCBs provide reliable power connections and stable performance, meeting the extremely high reliability requirements of medical equipment.

Aerospace
In aerospace equipment such as satellite power systems, radar transmitters, and aircraft engine controllers, Heavy Copper PCBs can operate stably in extreme environments due to their high reliability and strong performance.

Twenty years of industry experience is a testament to our strength. If you are looking for a reliable Heavy Copper PCB manufacturer, whether it’s a complex project or an urgent need, we are confident in providing you with high – quality products and services. Contact us now at [email protected] and let’s work together to create more powerful and reliable electronic devices!