Heavy Copper Printed Circuit Board sheets, their benefits, Production
Heavy Copper Printed Circuit Board sheets, their benefits, Production, and Applications Printed Circuit Board (PCB) industry has continued to grow giving rise to an increased number of PEPs (Power Electronic Products). The circuit boards that are copper printed may either be termed as extreme or heavy copper PCBs. Most PCBs that are available commercially are made for application of low voltage, with copper traces made of copper weighing from between A oz/ft2 to 3 oz/ft2. A circuit made of heavy copper contains copper weighing between 4 oz/ft2 to 20 oz/ft2. On the other hand, extreme copper PCBs are made of copper weighing more than 20 oz/ft2 and 200 oz/ft2. The manufacturing of PCBs with heavy copper endows the sheets with various benefits including v Higher endurance to strains caused by heat v Higher capacity of current transmitted
Higher mechanical strength in the PTH holes and at the connector sites v Subjection to high temperatures without the circuit failing
Small product size: the product size can be reduced by using several copper weights on a single layer of the circuit
Products made of heavy copper PCBs are widely used in power supply systems and electronic devices. The extra copper that is found in the heavy copper PCBs ensures the board can achieve excellent thermal distribution, conduct higher current, and install several switches that are complex in nature within a space that is limited.
Heavy copper PCBs whether multilayer or double-sided, are made through copper plating and etching processes. Circuit layers begin as copper foil sheets, which are etched in a bid to remove any excess copper, and before being platted to increase the copper thickness to the pads, planes, and traces. For the heavy copper PCB, specialized plating and etching techniques are used, and they include differential etching and high-speed plating. Once that step is completed, the entire circuit is laminated using a substrate that is epoxy-based, e.g., polyimide or FR4. The advancement of the plating technology has enabled the heavy copper features to form by combining etching and plating leading to negligible undercut and straight sidewalls.
Heavy copper PCB sheets are used in the manufacture of military applications. The use of heavy copper in making high current circuits coupled with heavy copper plating within the vias, and further plated through the holes eliminates the relevance of adding parallel duplicate layers. Hence, this eliminates the risk of load sharing within multiple layers. The temperature rise as a result of board losses can be ascertained with greater accuracy and certainty, while failures emanating from thermal stress are reduced by the thick copper plating present in the holes. The heavy copper PCB sheets are used in different military applications including the power distribution panels, radar systems power supply, weapons control systems, monitoring systems, battery charger, and the windings of planar transformers containing high voltage power. Heavy Copper PCB sheets have been for a long time been used in the military, as well as the aerospace industry, and are currently gaining momentum in other industrial applications.