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3 Oz Copper PCB

Jarnistech > Heavy Copper PCB > 3 Oz Copper PCB
3 Oz Copper PCB

If you are considering enhancing the current carrying capacity of PCBs in your appliances or seeking a PCB that can efficiently handle high heat transfer, a 3 oz copper PCB could be an excellent choice. To provide clarity on this topic, the following guide presents a compilation of pertinent questions that will address any queries you may have about 3 oz thick copper PCBs. Let’s delve into the information below without delay.

What is 3 0Z Copper PCB?

A 3 oz copper PCB refers to a specific type of circuit board where the copper layers have a weight of approximately 3 oz. The arrangement of these copper layers follows a specific design to achieve a PCB with a weight of only 3 oz. It’s worth noting that there are various types of PCBs available with differing copper weights.

The design of the circuit board is influenced by the prescribed spacing of the copper around the PCB, which determines the specific layout of the board. The minimum thickness of the copper in 3 oz copper boards for PCB circuits is typically around 3.0mm, and the finished copper thickness in these PCBs is also 3 oz.

In 3 oz PCB circuits, the solder mask is typically white and serves to delineate the separation between the copper layers. The copper thickness in the PCB is a significant factor in determining both the thermal conductivity and the current carrying capacity of the board. As the copper thickness increases, so does the thermal and current conductivity of the PCBs.

Therefore, increasing the copper thickness in PCB circuits leads to improved thermal conductivity and higher current carrying capacity.

Main Features of 3 0Z Copper PCB

The specifications of a 3 oz Copper PCB are as follows:

Reinforcing Material:

The PCB is constructed using a combination of glass fiber and wood pulp as the reinforcing material. Additionally, it features a copper clad on both sides of the board, providing excellent conductivity.

Heat Dissipation:

The PCB is designed to enhance heat dissipation throughout the board, ensuring even distribution of heat and preventing potential damage caused by uneven heating.

International Standards:

The materials used in the PCB adhere to established guidelines and international standards, ensuring compliance, quality, and compatibility with industry requirements.


The PCB exhibits exceptional properties as both an electrical conductor and a heat conductor, enabling efficient transmission of electrical signals and effective heat transfer.

For further clarification or if you have any questions regarding these features, please feel free to reach out to us through our social media channels. We will be prompt in addressing your inquiries.

Benefits of 3 Oz Copper PCB

3 oz copper PCBs offer some benefits:

Increased Current Carrying Capacity: The thicker copper layers in a 3 oz copper PCB allow for higher current flow, making them suitable for applications requiring high power.

Reduced Power Loss: The lower resistance of thicker copper allows for reduced power loss and improved energy efficiency in the PCB.

Enhanced Thermal Management: The thicker copper layers can efficiently dissipate heat, helping to keep the PCB and components cool and preventing overheating issues.

Improved Signal Integrity: The lower resistance and reduced losses in 3 oz copper PCBs contribute to better signal integrity, minimizing signal attenuation and distortion.

Higher Reliability: Thicker copper layers provide increased durability and better resistance to thermal stress, enhancing the overall reliability and lifespan of the PCB.

Superior EMI/RFI Shielding: The increased copper thickness offers better electromagnetic interference (EMI) and radio frequency interference (RFI) shielding, ensuring improved performance in applications sensitive to electromagnetic interference.

Fine Trace and Space Capabilities: Despite their higher copper weight, 3 oz copper PCBs can maintain fine trace and space features, enabling high-density circuit design.

Future-Proofing: 3 oz copper PCBs can accommodate evolving technological requirements, making them suitable for advanced and high-performance electronic applications.

Applications Suited for 3 oz Copper PCBs

3 oz copper PCBs are well-suited for various applications that require high current capacity, efficient heat dissipation, and reliable performance. Some of the common applications where 3 oz copper PCBs are utilized include:

Power Electronics:

3 oz copper PCBs are ideal for power electronic devices such as inverters, motor drives, power supplies, and electric vehicle charging systems. They can handle high current levels without significant power loss, ensuring efficient power delivery while minimizing overheating risks.

Industrial Equipment:

3 oz copper PCBs are used in industrial equipment like robotics, automation systems, and heavy machinery controls. These applications often have demanding power requirements and benefit from the higher current-carrying capacity of 3 oz copper PCBs.

LED Lighting:

LED lighting fixtures require efficient heat dissipation to maintain optimal performance and prolong LED lifespan. 3 oz copper PCBs can effectively dissipate heat, making them suitable for high-power LED applications, including street lighting, commercial lighting, and stadium lighting.

Renewable Energy Systems:

Solar inverters, wind power converters, and other renewable energy systems necessitate PCBs capable of handling high currents and efficiently managing heat. 3 oz copper PCBs are well-suited for these applications due to their robust current-carrying capacity and thermal management capabilities.

Automotive Electronics:

Modern vehicles increasingly rely on advanced electronics and power-hungry components. 3 oz copper PCBs are employed in automotive applications like engine control units (ECUs), lighting systems, electric vehicle battery management systems, and high-power audio systems.

Aerospace and Defense:

The aerospace and defense sectors require PCBs that can endure harsh operating conditions, maintain stability, and handle high currents. 3 oz copper PCBs find application in avionics, satellite communication systems, military radar systems, and other electronic components for aerospace and defense applications.


Telecom infrastructure such as base stations, routers, and communication modules benefit from the reliable performance and high current capacity of 3 oz copper PCBs, ensuring efficient data transmission and signal integrity.

These are just a few examples of the applications where 3 oz copper PCBs are commonly used. Their ability to handle high currents, dissipate heat effectively, and provide reliable performance makes them valuable in various industries that rely on robust electronic systems.

What Materials Used in 3 Oz Copper PCB Manufacturing?

Manufacturers employ a variety of materials in the fabrication of 3 oz copper PCBs, and one such material is tin alloy. This component contributes to the overall thickness of the heavy copper PCB. Additionally, the 3 oz copper PCB incorporates other conductive materials to enhance its functionality.

Steel wood is commonly used in PCB circuits to provide robustness and stability to the board. Carbon steel is another material utilized in the production of heavy copper boards, and it is typically coated with resin.

Prepreg is an essential component incorporated into 3 oz PCBs to ensure the circuit can withstand extended temperature ranges. FR-4 materials are widely utilized for fabricating 3 oz PCBs, comprising epoxy reinforced fiberglass. FR-4 exhibits poor electrical conductivity, making it an effective insulator. Furthermore, FR-4 is lightweight while maintaining a rigid mechanical structure.

Key Factors to Consider When Selecting Materials for 3 oz Copper PCBs

When selecting materials for 3 oz copper boards, it is crucial to consider the following:

Thermal Conductivity: Assess the material’s ability to conduct heat effectively.

Impedance Control: Verify that the material meets the required impedance specifications.

Material Thickness: Ensure the chosen material meets the desired thickness requirements for the 3 oz copper PCB.

Dk (Dielectric Constant) of the Material: Examine the dielectric constant of the material as it impacts signal propagation and impedance control.

By carefully considering these factors during material selection, manufacturers can create reliable and high-performance 3 oz copper PCBs.

Design Considerations for 3 oz PCB Fabrication

Determining the thickness of the copper conductor trace is a crucial task for manufacturers prior to designing a 3 oz copper PCB. In the fabrication of such PCBs, there are several important design considerations to keep in mind:

Trace spacing:

It is essential to recognize that heavier copper PCBs require increased spacing. For 3 oz metal copper boards, a minimum spacing of 10 mils is recommended. The spacing between traces is determined by considerations of creepage and clearance, which are vital for minimizing the risk of flashover.

Connection points:

Clear and well-defined markings should be employed to indicate the locations of electronic components on the PCB. This facilitates the use of appropriate masking techniques during fabrication.

Trace width:

The width of the conductive trace on the board surface, known as trace width, is critical for establishing connections with components. The current-carrying capacity of the conductor path is determined by the trace width, making it an important factor to consider.

Hole placement:

The strategic placement of drilled holes is a key design consideration. Accurate hole placement is imperative to avoid interfering with the overall board design. Any misplacement of holes can result in financial costs and other manufacturing complications.

Overall, when designing a 3 oz copper PCB, manufacturers need to carefully consider trace spacing, connection points, trace width, and hole placement. Adhering to these design considerations ensures the fabrication of a high-quality PCB that meets the necessary electrical and functional requirements while minimizing the risk of issues during production.

Comparison of 3 oz to Standard 1 oz Copper

Parameter1 oz Copper3 oz Copper
Copper Thickness1 oz/ft2 (35 μm)3 oz/ft2 (105 μm)
Trace ResistanceHigher~65% lower
Current CapacityLower~2.5x higher
InductanceHigher~2x lower
Thermal ConductionModerateImproved
EMI ShieldingFairExcellent attenuation
Fine Line Capability3-4 mil lines/spaces2-3 mil lines/spaces
CostLowerModerately higher

In high-power, high-frequency, or mission-critical applications, utilizing 3 oz copper instead of the standard 1 oz foil yields significant performance enhancements. The increased copper thickness offers substantial improvements, making it the preferred choice for demanding applications.

How Thick is 3 oz Copper PCB?

The thickness of a 3 oz copper PCB is typically estimated to be up to 10 mil or 0.254mm, which is equivalent to 105 microns. This substantial thickness gives the PCB its “Heavy Copper PCB” designation. To create a multi-layer PCB, the heavy copper PCB is integrated with PCBs of different thickness levels.

During the manufacturing process, a high-quality solder mask is carefully applied to align the copper layers, achieving the desired thickness level for the PCB circuit board. Manufacturers like JarnisTech offer services to produce PCB circuit boards with various thickness levels to meet specific requirements.

To avail of such services, simply visit their website and inquire about the desired thickness level for the copper PCB circuit boards. They will provide you with high-quality PCB circuit boards to meet your needs.

How to Measure the Weight of 3 0Z Copper PCB?

The weight specifications of a 3 oz copper PCB are determined by estimating the thickness of the copper layers within the PCB. Typically, the weight of a copper PCB is measured in ounces per square foot. Alternatively, the minimum copper-covered area on the PCB can also be used to estimate its weight.

The weight of the copper PCB is directly linked to the thickness of the copper present in it. The greater the number of copper layers in the PCB, the heavier the PCB will be. The thickness of the copper PCB can be observed by examining the rolled-up PCB, unless it covers an area of one square foot.

Furthermore, the weight of a 3 oz copper PCB is influenced by several factors, such as the assembly of connectors on the board, component compatibility within the PCB circuit, and impedance control.

These factors collectively contribute to the overall weight of the thick copper PCB.

How to Choose the best 3 oz Copper PCB Manufacturer?

Choosing the best 3 oz copper PCB manufacturer involves considering several factors to ensure you receive high-quality products and reliable services. Here are some key aspects to consider:

Quality and Standards:

Look for a manufacturer that maintains high-quality standards. Check if they follow industry-standard manufacturing processes, adhere to international quality certifications (e.g., ISO 9001), and have a solid track record of delivering reliable products.

Experience and Expertise:

Assess the manufacturer’s experience in producing 3 oz copper PCBs. A manufacturer with extensive experience is more likely to have the technical expertise, advanced equipment, and skilled personnel to meet your specific requirements.

Capability and Capacity:

Evaluate the manufacturer’s capabilities and capacity to handle your project. Consider factors such as production volume, lead time, PCB layer count, and the ability to meet your customization needs. Make sure they have the necessary infrastructure and resources to fulfill your orders efficiently.

Pricing and Cost-effectiveness:

While cost shouldn’t be the sole deciding factor, it’s essential to evaluate the manufacturer’s pricing structure to ensure it aligns with your budget. Obtain quotes from multiple manufacturers and consider their pricing in conjunction with the quality of their products and services.

Customer Support and Communication:

A reliable manufacturer should provide excellent customer support and be responsive to your inquiries and concerns. Look for clear and open communication channels, prompt response times, and a commitment to understanding and meeting your specific requirements.

Additional Services:

Consider any additional value-added services offered by the manufacturer, such as design assistance, prototyping, PCB assembly, and testing. These services can streamline your PCB development process and reduce the need for multiple suppliers.

By carefully considering these factors, you can make an informed decision and choose the best 3 oz copper PCB manufacturer that aligns with your specific needs, ensuring high-quality products, timely delivery, and reliable support.


With three times the thickness of standard 1 oz foils, 3 oz copper provides a significant boost in current capacity, allows for finer features, reduces losses, improves thermal management, enhances reliability, and offers superior EMI control. These advantages position 3 oz copper as the material of choice for cutting-edge high-performance and high-reliability electronics.

To fully leverage the capabilities of 3 oz copper, engineers must employ disciplined layout and design practices tailored to the finer geometries and higher densities achievable. By adhering to proper design principles, 3 oz copper PCB technology empowers electronics to meet present demands and future requirements.

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