Guide

What is Thick Copper PCB and its Applications?

As we all know, in a world full of electronics, how important PCBs are? It acts as the nerve centre, offering a platform for the interconnection of numerous electronic parts, allowing the development of sophisticated and compact electronic systems. PCBs enable the smooth flow of electrical impulses by linking diverse components and ensuring the functionality of electronic systems.

In today’s time, a special category known as Thick Copper PCBs has arisen, playing an important role in applications that require high performance, excellent heat dissipation, and effective power management.

1. What is a Thick Copper PCB

Speaking generally, the usual thickness of a PCB is around 35 μm (Micro Meter). We can call it a Thick copper PCB If the Thickness ranges from 100 to 500 μm (Micro Meter) or more. These PCBs can be double-sided or multi-layered.

Nowadays, the designs of circuits are so advanced that they can handle high currents. These high currents result in a decent heat output. Implementing thick copper PCBs in that type of situation can help in heat dissipation of the produced heat. This ensures that the circuit operates at its best. This is one of the main reasons why thick copper PCBs are very high in demand even though it has a high pricing.

PCB With Thick Copper

2. Applications of Thick Copper PCBs

Because of their excellent current carrying capacity, thermal conductivity, resistance to corrosion and remarkable mechanical performance, thick copper PCBs are widely used in a lot of industrial areas, such as automotive, power, energy, aerospace and defence, medical, automation., etc.,

  • 2.1 Automotive
    Thick copper PCBs are used in a range of applications in the automotive sector. They are implemented in the motor controllers, power sources, battery management systems, and interior electronic applications of EVs (Electrical Vehicles). It is used effectively in EVs because of the durability, higher efficiency and performance because of larger current loads and better thermal control of the boards.
  • 2.2 Power Electronics
    The ability to tolerate high current levels while dissipating heat effectively is one of the major reasons why thick copper PCBs are used in power electronics. Its common applications are in power supply, Converters, and inverters.
  • 2.3 Aerospace and Defense
    In the aerospace and defence industry, the materials used must have a high survival instinct because of the harsh environmental conditions its products have to go through. They must attain the ability to survive extreme weather conditions. So by using thick copper PCBs in this application can expand the lifetime and durability of electronics built into the devices. We can see its involvement of in avionics, wired and wireless communication systems, radar systems etc.
  • 2.4 Renewable Energy
    The ability to withstand high power levels and heat regulation makes thick copper PCBs an ideal choice for renewable energy systems such as solar inverters and wind turbine controllers.
  • 2.5 Medical Electronics
    Medical devices frequently have high reliability and performance requirements. The medical field utilizes thick copper PCBs Unique features in applications like medical imaging devices, patient monitoring systems (PMS), and in instruments used for diagnosing.
  • 2.6 High-Performance Computing
    In data centres, for computing itself, there is a requirement for devices that can dissipate heat. However, for high-performance computing, the heat dissipation will be extreme. So, by using thick copper PCBs, we can handle the critical heat because of the durability and thermal performance it can achieve by using this PCB.
  • 2.7 Industrial Automation
    Industrial Automation highly depend on high current and voltage for the working of heavy-duty machines. Thick copper PCBs will help to withstand the heavy current and voltage in the circuitry and help in the smooth running of industrial production.
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3. Manufacturing Process of Thick Copper PCB

The manufacturing process of thick copper PCB follows almost similar steps of standard PCBs and the only difference apart from the standard one is the thickness of copper used. Following is the step-by-step manufacturing process which is implemented:

  • Design: The design or layout of the PCB to be manufactured is drawn out of specific designing software according to the specific requirements of circuits. While designing, make sure that the design meets the electrical and thermal requirements as well as the thickness of the copper used.
  • Choosing the Substrate material: Substrate materials are usually selected based on their ability to handle a thick copper layer. For that reason, the material used is usually a high-temperature FR-4. By using electrodeposition or lamination techniques, a thick copper foil is applied to the substrate. The thickness of the copper layer here is usually greater than 2 oz (ounces) or 70 micrometres.
  • Lamination: It is the next step which involves copper layers pressing together using heat and pressure to build a strong board. This process assures good adhesion between the layers.
  • Drilling: Holes are drilled into the board according to the PCB design in particular locations. These holes allow the interconnection between layers and will hold the electronic components together.
  • Through-Hole Plating: For creating a strong and dependable circuit, this step is really important. This is the process of plating conductive material along the drilled holes in order to create electrical connections.
  • Circuit imaging: A photosensitive material called resist is enforced over the copper layer and it is then exposed to UV light through a mask which is of the PCB layout. This will form the circuit pattern of the PCB.
  • Etching: The exposed copper protected by the resist stays behind and the copper which is not protected by the resist is etched away using a particular chemical solution. Through this process, we can leave the intended copper traces on the PCB.
  • Surface Finish: This process will prevent PCBs from oxidation and improve the solderability of the exposed copper traces. There are some commonly used surface finishes such as Hot Air Solder Leveling (HASL), Organic Solderability Preservatives (OSP), Immersion Gold (ENIG)., etc.
  • Silkscreen and Solder mask: The solder mask serves to create openings for component placement in the board and protect the PCB. Component labelling and marking in the PCB is done by Silkscreen printing.
  • Testing and Final inspection: Various tests are done on the final PCBs before it is produced on the market. The electrical testing and quality control checks will ensure the overall quality of the finished PCB and ensure that it is defect-free.

Also read: The Comprehensive Guide to Estimating PCB Board Costs

4. The Advantages of Thick Copper PCB

Thick copper PCBs have many advantages, such as high current carrying capacity, high thermal conductivity, resistance to corrosion, excellent mechanical support., etc.

  • 4.1 Impressive current carrying capacity
    Thick copper PCBs offer higher current carrying capacity. The increased inner and outer layer thickness of the copper in the PCB is the main reason for that. It improves the current carrying ability of the circuit by increasing the area of conductivity of the board. Also, it makes use of the blind buried hole and distributed inductance technologies which will necessarily lower the current’s self–inductance and allows it to manage higher current.
  • 4.2 High Thermal Conductivity
    For thick copper PCBs, the copper thickness is more than 3oz (Ounce). Meanwhile, the thickness of ordinary PCBs is about 1 oz. So as we correlate with ordinary PCBs, the thick copper PCBs have more thickness and this has some strong applications including lowering line resistance, improving the thermal conductivity of the board, and extending the circuit’s lifetime and dependability.
  • 4.3 Excellent resistance to corrosion
    Copper has a high resistance to corrosion. In thick copper PCBs, copper is used abundantly and this will help the board to resist corrosion on a higher scale. This property will extend the service life and shelf life of the circuit Board.
  • 4.4 Improved Mechanical Performance
    The overall thickness of the board is comparatively high and because of that, these PCBs have greater mechanical strength. This will also help in protecting circuits in convoluted physical environments. Furthermore, it can be stacked in multiple layers and can be utilized for lots of practical applications. By stacking up, the overall structure of the PCB becomes more compact and durable.

Thick copper PCBs

5. Drawbacks of Thick Copper PCB

Although thickness copper PCBs have a lot of advantages, they also have some disadvantages, such as high cost, limitations in copper trace width and spaces, production difficulties., etc. Please refer to the following details.

  • 5.1 High Cost
    The major disadvantage of thick copper PCBs is the cost when compared with normal PCBs. The manufacturing techniques needed to attain thicker copper layers increase the overall cost.
  • 5.2 Specialized Design Consideration
    Designing circuits for thick copper PCBs requires specific care. Engineers must account for the increased copper thickness, which may impact impedance matching and signal integrity.
  • 5.3 Complex Manufacturing Process
    It has a more complex manufacturing process than normal PCBs require. To reach the necessary copper thickness, the etching and plating procedures must be precisely regulated, complicating the manufacturing process.
  • 5.4 Limitation of Layer Count
    While thick copper PCBs have lots of advantages, they can be an issue for certain complex electronic designs that require more layers and high-density copper traces.
  • 5.5 Limited Material Availability
    The availability of materials with the requisite thickness may be limited, making obtaining these materials difficult, particularly for highly specialized applications.

Also read: Electronics Product Development from Idea to Finished Device

Conclusion

As we conclude, Thick copper PCBs are an important component in the advanced world of electronic circuitry. It is mainly because of its ability to manage things such as high current, heat dissipation and reliability.

They are advanced and unique in their current carrying capacity, thermal conductivity, resistance to corrosion and remarkable mechanical performance. They also guarantee optimal performance, durability and good lifespan and can be used in oodles amount of applications such as automotive systems, power electronics, aerospace, defence, medical equipment etc. The demand for these PCBs is expected to remain high as more high-power electronic gadgets are manufactured.

In summary, thick copper PCBs are not just an improvement in PCB technology but also solutions for engineers and designers who want to push the limits of the electronic world.

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