Copper-based circuit boards are said to be the most durable. Why? Well, you can find the answer here!
Copper is the most common material used in circuit boards because it’s both affordable and durable. However, what if the copper content of a PCB exceeds the standard percentage of copper on one?
In this article, we’ll be explaining heavy copper PCB and its effectiveness as a heavy-duty circuit, Also, we will explain how they are used to build some of the most reliable electronics where electricity flux is high.
What is heavy copper PCB?
We know PCBs are made of non-substrate and copper material where copper works by conducting electricity through the circuit. In thick or heavy copper PCB, a higher concentration of copper (not like copper-clad where layers of copper are used) is used, which makes it an ideal PCB type to use in heavy electrical devices.
Usually, the standard PCB has a copper thickness of around 1-1.4 ounces/square foot, which is enough to supply the current efficiently from circuit to standard applications (not heavy-duty). Whereas, in copper thickness of a heavy copper PCB the copper percentage is 3 ounces or more per square foot which is known as extreme copper, making it used in many different high-electricity supply applications to prevent damage to electric appliances from sudden electricity collapse that’s usually a thing with thin film PCBs.
A brief look at heavy copper PCB characteristic
Some prominent characteristics of heavy copper PCB that make it different from other PCBs include:
- Long-term toughness: Higher copper content provides added strength and support to the circuit board and makes it exceptional for heavy tasks.
- Heat dissipation: The high level of copper in a heavy copper PCB can help dissipate heat, making them suitable for use in high-temperature environments.
- Increased current-carrying capacity: Making it suitable for use in high-power applications.
- Improved signal integrity: Help improve signal integrity by reducing crosstalk and other forms of interference.
Design considerations for thick-copper boards
Designing thick-copper boards requires careful consideration to ensure optimal performance and reliability.
1.Thermal Management: Thick-copper boards are often used for high-current or high-power applications where effective heat dissipation is crucial. Ensure that the design includes adequate thermal pathways and heat sinks to prevent overheating and maintain performance.
2.Current Carrying Capacity: The thicker copper layers enhance the board’s ability to handle higher currents without excessive heating. Design trace widths and spacing according to the expected current loads and ensure they meet industry standards for safe operation.
3.Thermal Expansion: Thick copper can expand and contract with temperature changes, potentially causing stress on solder joints and components. Design the board to accommodate thermal expansion, including the use of appropriate soldering techniques and materials to minimize thermal stress.
4.Mechanical Strength: The increased thickness of the copper adds mechanical strength to the board, which can be beneficial for rugged applications. Ensure that the board’s mechanical design supports the additional stress and strain, especially around mounting holes and connectors.
5.Fabrication Considerations: Manufacturing thick-copper boards requires specialized processes and equipment. Work closely with your PCB manufacturer to ensure that the design can be fabricated according to their capabilities and that all design rules are followed.
6.Signal Integrity: For high-frequency or high-speed applications, thick copper can affect signal integrity. Proper design practices, such as careful routing and impedance control, are necessary to maintain signal quality.
When designing thick-copper boards, focus on managing thermal performance, ensuring current capacity, accommodating thermal expansion, maintaining mechanical strength, and considering fabrication and signal integrity requirements.
PCBs with heavy copper have several advantages
- A more conductive and current-carrying PCB than other types.
- Can be used in applications that require a lot of stress on the circuit board.
- Resistant to electrical corrosion and oxidation, which means that it won’t corrode or oxidize as easily as other types of PCBs do over time
- Better thermal conductivity, which means the heat will move through it faster and keep your device cool during use
Applications of heavy copper PCB
It has been observed that compact design, rich copper content, and seamless characteristics make heavy copper PCB used in heavy-duty applications, including:
- For rail traction systems, the goal is to provide a stable supply of power for the train motors and increase train speed.
- In solar power converters to handle high current loads and provide a stable power supply to increase efficiency, reduce cost, and improve reliability.
- In nuclear power industries to reduce costs, improve safety, and increase safety standards.
- In automotive industries to improve efficiency and reduce operating costs by reducing friction between parts that come into contact during normal operation such as wheels and tires.
How to choose the right copper thickness
Choosing the right copper thickness for a PCB is crucial to ensure its performance, reliability, and cost-effectiveness. Here’s a streamlined guide to making the right choice:
1.Current Carrying Requirements: Determine the amount of current the PCB needs to handle. Thicker copper layers can carry higher currents without excessive heating. Use current-carrying capacity charts or guidelines to match the copper thickness with your current requirements.
2.Thermal Management: Consider the thermal demands of your application. For high-power or high-heat applications, thicker copper helps with heat dissipation and thermal conductivity, reducing the risk of overheating.
3.Mechanical Strength: Thicker copper enhances the mechanical strength of the PCB, which can be beneficial for boards subject to physical stress. Evaluate if additional mechanical strength is needed for your specific application.
4.Signal Integrity: For high-frequency or high-speed designs, the thickness of the copper can impact signal integrity. Ensure that the chosen thickness does not negatively affect the impedance and signal performance.
5.Cost Considerations: Thicker copper increases manufacturing costs. Balance performance needs with budget constraints to choose an appropriate thickness that meets your requirements without overspending.
6.Design and Fabrication Constraints: Check with your PCB manufacturer about their capabilities and recommendations for copper thickness. Ensure that your design aligns with their fabrication processes and tolerances.
By evaluating these factors—current needs, thermal management, mechanical strength, signal integrity, cost, and manufacturing capabilities—you can select the optimal copper thickness for your PCB, ensuring it performs reliably and efficiently for your specific application.
Differences between copper PCB and heavy copper PCB
You don’t need to confuse copper PCB with heavy copper PCB, as both of them are different in many aspects, like:
List of features | Copper PCB | Heavy copper PCB |
Layer of copper foil | Thinner layer of copper foil | Thicker layer of copper foil |
Copper percentage | 1 oz or 1.4 oz per square foot | 3 oz or more per square foot |
Usage in applications | Used in a wide range of applications in which flux of electricity is not a concern | Used in applications that require higher power handling or higher current density |
Efficiency | Can be efficient for most standard applications | More efficient in high-current or high-power applications |
Cost | Less expensive than heavy copper | More expensive due to heavy copper used |
What is the relationship among current and copper thickness and line width?
To understand this relationship, let’s first understand what is copper thickness and line width.- Copper thickness represents the copper proportion used.
- Line width is the distance between lines on a printout.
4 steps manufacturing process of heavy copper PCB
- Design and layout: This includes determining the size and shape of the PCB, as well as the placement of components and trace patterns.
- Photolithography: It involves exposing the film to light and then developing it, creating a negative image of the PCB layout.
- Etching: Copper is applied to the PCB substrate, followed by selective removal of copper using a film.
- Plating: It is for the thickness of copper and involves electroless plating, electroplating, or a combination of both.
PCBs made of heavy copper: Important Considerations!
A manufacturer’s quality is the most important consideration when making copper PCBs.
It’s important that you find a manufacturer with a good reputation for quality and customer service, as well as the ability to meet your needs. It is essential considering that they are capable of producing large quantities of copper PCBs at a reasonable cost for you.
- Long-term toughness: Higher copper content provides added strength and support to the circuit board and makes it exceptional for heavy tasks.
- Heat dissipation: The high level of copper in a heavy copper PCB can help dissipate heat, making them suitable for use in high-temperature environments.
- Increased current-carrying capacity: Making it suitable for use in high-power applications.
- Improved signal integrity: Help improve signal integrity by reducing crosstalk and other forms of interference.
Copper thickness and line width have a relationship because they affect how much current flows through a wire, affecting how quickly heat can be transferred to ink or toner particles in a printer head.
Yes, it is possible to make a heavy copper PCB with two layers. In fact, it is possible to make this with any number of layers as far as the proper design is made accurately.
In general, it is safe to use a heavy copper PCB in an electronics project as long as the PCB is designed and manufactured correctly and the PCB is used within its specified operating parameters.
The maximum thickness of copper on a PCB typically ranges from 1 ounce per square foot (about 35 micrometers) to 6 ounces per square foot (about 210 micrometers). The choice of copper thickness depends on the specific requirements of the application:
Standard Thickness: Most PCBs use standard copper thicknesses of 1 or 2 ounces per square foot, suitable for general applications.
Heavy Copper: For high-power applications where greater current carrying capacity and enhanced thermal management are needed, copper thicknesses up to 6 ounces per square foot can be used.
Specialized Applications: In some cases, particularly in specialized or high-performance applications, even thicker copper layers can be required. However, these are less common and usually involve custom manufacturing processes.
The choice of maximum copper thickness should be guided by the PCB’s electrical and thermal requirements, mechanical considerations, and the capabilities of the PCB manufacturer.
The weight of copper on a PCB is commonly expressed as ounces per square foot. This measurement indicates the thickness of the copper layer:
Standard Weight: The most common copper weight used in PCBs is 1 ounce per square foot, which corresponds to a thickness of approximately 35 micrometers (1.4 mils). This is suitable for general electronic applications.
Heavy Copper: For applications requiring higher current carrying capacity or improved thermal performance, heavier copper weights are used. These can range from 2 ounces to 6 ounces per square foot, translating to thicknesses of around 70 micrometers to 210 micrometers (2.8 to 8.3 mils).
Specialized Needs: In certain high-power or specialized designs, copper weights beyond 6 ounces per square foot may be used, but these are less common and typically involve custom manufacturing processes.
Final words
If you’ve been searching for a reliable heavy copper PCB manufacturer, we suggest checking out IBE for all types of PCB manufacturing, specifically if you aim to design efficient circuits for use in heavy-duty applications. This China-based company is in business since 2005 and based on experience, can provide best out of best!
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Last updated on September 2nd, 2024 at 01:03 am