Heavy copper PCB is printed circuit board (PCB) that contains 3 ounces of copper or even more on the inner layers or the outer layers. It is normally produced using copper weights that lie in the range of 4 oz per ft2 up to 10 oz per ft2. The appropriate substrate, a thicker plating and improved copper weight can positively transform weak boards into dependable and long-lasting wiring platform. The main advantage of heavy copper PCB is their unique ability to survive the frequent exposure to recurring thermal cycling, elevated temperatures and excessive current.
Structure:
Printed Circuit Boards are mechanical assemblies that comprise of layers of fibreglass sheets laminated using etched copper patterns. Standard PCBs regardless of whether they are double-sided or multilayered are manufactured through the combination of metal plating and copper etching processes.
The two most common techniques used in the production of heavy copper PCB are differential etching and high speed plating.
Benefits:
Heavy copper PCB is associated with several added advantages, the notable ones include the following:
• Compact – It results in a product size that is compact because numerous copper weights are placed on one layer of circuitry.
• There is an increase in current carrying capacity.
• There is an increase in mechanical strength in PTH holes and at connector sites.
• It allows for on-board heatsinks to be plated directly on the board surface with 120-oz copper planes.
• Heavy copper PCB allows for the optimum use of exotic materials without risk of circuit failure.
• Elevated current can be passed through a PCB by a heavy copper-plated vias. This can assist in heat transfer to an external heat sink.
Conclusion:
Heavy copper PCB is a bit more expensive compared regular PCBs. However, this is a factor of special design, the more complicated a design, the higher the price. Heavy copper plating on high speed materials like Teflons, Polyimide, Ceramic is the reason why it cost more and it's for mission critical component/product that you have to consider the high level of quality consistency.