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20 Oz Copper PCB

Jarnistech > Heavy Copper PCB > 20 Oz Copper PCB
20 Oz Copper PCB

With the increasing power densities observed in advanced electronics, there is a growing trend towards adopting thicker copper printed circuit boards (PCBs) that surpass 10 oz. Achieving exceptional performance necessitates the use of 20 oz copper PCBs, which boast an extreme foil thickness of 700 μm (0.7 mm). Nonetheless, the process of reliably manufacturing multilayer PCBs with 20 oz copper poses significant fabrication challenges. In this article, we delve into the advantages offered by 20 oz copper boards, the exacting manufacturing capabilities they demand, potential applications for this cutting-edge PCB technology, as well as key considerations to bear in mind when implementing it.

What is a 20 oz Extreme PCB?

The copper thickness of PCBs is typically measured in ounces per square foot (oz/ft2), indicating the weight of copper foil in one square foot of board area, excluding the dielectric substrate. Common copper weights include 1 oz (35 μm), 2 oz (70 μm), 10 oz (350 μm), and 20 oz (700 μm) options.

A 20 oz PCB refers to a printed circuit board with a substantial thickness of 20 oz copper. Such PCBs possess significant thermal energy capacity and are capable of handling large current values. To determine the thickness of a 20 oz PCB, we need to understand the thickness of a 1 oz PCB and multiply it by 20. A 1 oz PCB typically has a thickness of 1.37 mils or 0.00137 inches. Hence, a 20 oz metal core PCB would have a thickness of 20 multiplied by 1.37 mils, resulting in 27.4 mils or 0.0274 inches.

Essentially, a 20 oz copper PCB contains 20 ounces of copper foil per square foot on each metal layer. In terms of thickness, 20 oz copper translates to approximately 700 μm (0.7 mm) or 28 mils. This substantial foil thickness allows for exceptional power handling and enhances overall reliability capabilities.

Benefits of 20 oz Copper PCBs

The utilization of 20 oz copper PCB technology offers several significant advantages, including:

Highest current capacity: The substantial copper cross-section enables 20 oz copper PCBs to handle extremely high current loads without overheating, ensuring reliable performance.

Lowest losses: With minimal resistive losses, these PCBs facilitate highly efficient power transfer and conversion, reducing energy wastage.

Finest thermal performance: The thick copper layers act as effective heat spreaders, efficiently dissipating heat and contributing to optimal component temperature management.

Superior shielding: 20 oz copper PCBs feature thick and uninterrupted copper planes that provide exceptional electromagnetic interference (EMI) isolation, ensuring reliable signal integrity.

Extreme reliability: These PCBs exhibit high resistance to challenges such as thermal cycling, electromigration, and physical stresses over prolonged periods, enhancing overall reliability and longevity.

Low voltage drop: The minimal resistivity of the thick copper enables negligible voltage loss along power distribution paths, ensuring proper power delivery.

High power density: 20 oz copper PCBs offer the maximum power delivery potential within a given PCB footprint, making them suitable for applications requiring high power densities.

Component integration: The presence of 20 oz copper inner planes allows for the embedding of heavy power components, facilitating efficient and compact PCB designs.

The utilization of 20 oz copper represents the forefront of PCB material technology, meeting the demands of extreme electrical and thermal requirements in various applications.

Design Process of the 20 oz PCB

Before proceeding with the design of a 20 oz PCB, it is crucial to consider certain parameters such as spacing, ideal dimension, and parts type. These parameters will guide you in the following steps:

Pay attention to copper fill levels in the inner layers to prevent excessively low resin levels. Insufficient resin can lead to voids between the board’s layers, potentially causing delamination.

Utilize software tools to assist in determining the types and quantities of prepregs required for achieving multilayer designs effectively.

Give due consideration to the galvanic coating aspect. Working with 20 oz PCBs necessitates the use of more galvanic copper compared to other copper thicknesses.

Ensure the layers of solder resist are applied with adequate thickness. This will provide sufficient protection for the mosaic edges on the PCB. For example, the end circumferential thickness should be at least 0.25mm thicker than the initial thickness.

By factoring in these considerations and taking the necessary precautions during the design process, you can ensure optimal performance and reliability of your 20 oz PCB.

Manufacturing Challenges with 20 oz Copper

The fabrication of 20 oz copper multilayer PCBs presents significant challenges due to various factors:

Registration: The cumulative tolerance across the 0.7 mm thickness of copper can lead to layer misalignments and difficulties in achieving precise registration.

Aspect Ratios: Plating holes with extremely high aspect ratios, such as 28:1, poses a considerable challenge in maintaining uniform plating throughout the hole.

Lamination Voids: It is crucial to prevent any areas of filler starvation or voids during the bonding process, requiring meticulous precision and control.

Surface Finish: Attaining uniform plating on coarse high copper weight foils is a complex task due to the surface characteristics of the 20 oz copper.

Fine Lines: Defining very fine traces on rough 20 oz foil surfaces presents difficulties in achieving the desired line precision and quality.

Layer Peel Strength: Establishing a very high adhesion level between layers is essential to mitigate the risk of delamination.

Via Filling: Copper plating high aspect ratio holes without any pore formation demands specialized processes to ensure pore-free via filling.

Hole Wall Quality: Smooth and resin-rich hole walls are critical to enable proper copper plating and ensure the integrity of the plated vias.

Drilling: Achieving straight vertical through holes without taper or breakage requires the use of specialized drill bits and rigs.

Panel Stress: Minimizing cumulative stresses, as well as addressing issues like bowing and twisting during fabrication, is crucial to maintain the integrity and reliability of the PCB.

These factors necessitate the utilization of highly mature manufacturing capabilities, stringent controls, and advanced techniques to consistently produce high-quality 20 oz PCBs.

Methods for Making 20 Oz PCB

The production of 20 oz PCBs presents specific challenges compared to the manufacturing of regular boards. These difficulties primarily involve drilling processes, laminated structures, solder mask printing, and etching accuracy. Currently, three methods are commonly employed in the production of heavy copper PCBs:


Due to the limited availability of thick copper foils in the market, manufacturers typically start with 5 oz copper foils. Higher thickness orders are processed by electroplating to increase the copper thickness. However, this method poses challenges in terms of plating time, electroplating equipment capacity, overall cost, and ensuring uniformity in both plating and etching processes.


This method involves laminating one layer of heavy copper foil onto the board. While this approach offers better uniformity in copper thickness compared to electroplating, it still requires multiple etching steps to achieve the desired pattern.


In this method, both sides of the copper foil are etched. Initially, one side of the copper foil is etched with a pattern at half-depth. This etched pattern is then pressed onto the board and processed further in alignment with the regular production process after lamination. The second side of the copper foil is etched subsequently, along with the remaining copper thickness and the substrate, leaving the initial pattern pressed into the substrate.

These methods, though challenging, are employed to overcome limitations in the availability of thick copper foils. Each approach has its specific considerations, including cost, uniformity, etching accuracy, and the overall production process. Manufacturers carefully evaluate these factors to determine the most suitable method for producing 20 oz PCBs.

Applications of 20oz Printed Circuit Boards

A 20oz PCB refers to a printed circuit board with a copper weight of 20 ounces per square foot (oz/ft²) or approximately 6.93 kilograms per square meter (kg/m²). The copper weight indicates the thickness or amount of copper present on the PCB’s surface.

PCBs with a higher copper weight, such as 20oz, are typically used in applications that require high current carrying capacity, low resistance, and efficient heat dissipation. Here are a few examples of applications where a 20oz PCB might be suitable:

Power Electronics:

In power electronics applications, such as motor drives, power inverters, or high-power amplifiers, where high currents flow through the PCB, a 20oz copper weight can handle substantial power transmission while minimizing resistance and voltage drops.

High-Current Applications:

PCBs with 20oz copper are also suitable for applications involving high-current circuits or power distribution, such as electric vehicle (EV) charging stations, industrial machinery, or large-scale power supplies.

LED Lighting:

LED lighting systems, particularly those used in commercial or industrial settings, often require efficient heat dissipation due to the high power levels involved. A 20oz PCB can provide excellent thermal conductivity, helping to dissipate heat generated by the LEDs and prolonging their lifespan.

RF/Microwave Applications:

Radio frequency (RF) and microwave circuits often require specific impedance matching and controlled transmission line properties. A 20oz PCB can be used to design RF/microwave components like filters, amplifiers, or antennas that need low-loss characteristics and precise signal integrity.

High-Frequency Applications:

For applications involving high-frequency signals, such as wireless communication systems or radar systems, a 20oz PCB can help maintain signal integrity, reduce signal loss, and minimize impedance variations.

It’s important to note that PCBs with higher copper weights are generally more expensive and may require specialized fabrication techniques. The design and manufacturing of such PCBs usually involve factors like thicker copper plating, wider traces, and appropriate thermal management considerations.

When considering a 20oz PCB, it is recommended to consult with a professional PCB manufacturer or engineer who can provide specific guidance based on your application requirements, budget, and manufacturing capabilities.

20 oz Extreme PCB Manufacturer – JarnisTech

When it comes to 20 oz PCBs, their heavy copper composition necessitates specialized technologies to ensure optimal outcomes. It is crucial to collaborate with a reputable PCB manufacturer who can deliver high-quality results despite the challenges involved in fabricating such thick copper boards. One such exceptional manufacturer is JarnisTech, with years of experience in this field.

JarnisTech possesses the necessary expertise and knowledge to design and produce top-quality PCBs that meet your specific requirements. Our team understands the intricacies of working with 20 oz copper thickness and can leverage our experience to deliver reliable and cost-effective solutions for your printed circuit board needs.

By choosing to work with JarnisTech, you can benefit from our expertise and dedication to delivering superior results in the realm of 20 oz PCBs. Trusting their proven experience, you can have confidence in receiving a high-quality PCB design tailored to your precise specifications.

The Importance of 20 oz Copper Thickness in Heavy Copper PCBs

Printed Circuit Boards (PCBs) are a critical component in electronic devices. They provide the physical infrastructure for arranging electronic components and conductive pathways for electrical signals. The thickness of the copper layers on a PCB plays a significant role in its performance and durability, especially in high-power or high-current applications. A “heavy copper” PCB refers to boards with a copper thickness of 3 oz/ft^2 to 20 oz/ft^2. Let’s explore the importance of 20 oz copper thickness in heavy copper PCBs.

Enhanced Current Carrying Capacity

The thickness of copper on a PCB directly impacts how much current it can carry without overheating. A 20 oz copper PCB can handle significantly higher current loads compared to a standard PCB. This makes it an ideal choice for applications that require high power or high-current loads, such as power converters or automotive systems.

Superior Thermal Management

Heavy copper PCBs with a thickness of 20 oz have a greater ability to dissipate heat. This leads to better thermal management, which is crucial for high-power electronics and systems that operate in high-temperature environments. Better thermal management can increase the lifespan of the components and the PCB itself.

Increased Mechanical Strength

A 20 oz copper thickness provides added mechanical strength to the PCB. This increased strength is beneficial in applications where the PCB may be subjected to physical stress, such as in industrial or automotive applications. The additional copper thickness can help resist damage from vibrations, collisions, and other physical impacts.

Improved Reliability

The higher the copper thickness, the more reliable the PCB. Heavy copper PCBs are less likely to fail under high stress or high-power conditions, making them ideal for critical applications where failure is not an option.

Cost-Effective for High-Power Applications

While the cost of manufacturing heavy copper PCBs is higher than standard PCBs, they can be more cost-effective in the long run for high-power applications. The increased durability, reliability, and superior thermal management of heavy copper PCBs can reduce maintenance costs and increase the lifespan of the device, leading to overall cost savings.

In conclusion, the use of 20 oz copper thickness in heavy copper PCBs is crucial in specific applications. It allows for enhanced current carrying capacity, superior thermal management, increased mechanical strength, and improved reliability, making them an ideal choice for high-power, high-stress applications.


As electronic systems strive for greater performance and power densities, the utilization of 20 oz copper PCBs with 0.7mm thick copper has emerged as the cutting-edge solution in PCB fabrication. These advanced PCBs offer unparalleled capabilities in terms of current capacity, thermal management, and reliability. However, achieving flawless quality and high yield rates necessitates overcoming substantial manufacturing challenges on a large scale.

To mitigate risks and ensure successful implementation of state-of-the-art 20 oz copper PCB technology, it is crucial to establish a partnership with an esteemed PCB company that possesses proven expertise in this highly specialized arena. Selecting an elite PCB company with deep knowledge and experience in manufacturing 20 oz copper PCBs is instrumental in overcoming complexities and ensuring optimal results.

By collaborating with such a reputable company, you can access invaluable support, guidance, and resources that are vital for navigating the intricacies of 20 oz copper PCB fabrication. This strategic partnership minimizes risks, maximizes efficiency, and enhances the overall success of your implementation of leading-edge 20 oz copper PCB technology.

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