Heavy Copper

Definition of Heavy Copper PCB

Heavy copper does not have a set definition per IPC. However, the industry generally accepts the definition to be the use of 3 ounce copper or higher in inner and/or outer layers of a printed circuit board.

Applications

Heavy copper can be used for a variety of purposes, including, but not limited to, high power distribution, heat dissipation, planar transformers, and power convertors.

Common Issues / Saturn Solutions

Cost

Saturn is one of the 50 largest PCB fabricators in North America, and is regularly in the top 5 in terms of heavy copper material usage, We have a history of producing heavy copper PCB for automotive and commercial applications. As a result, we are able to negotiate some of the most favorable materials pricing in the industry.

From a processing standpoint, we have optimized our processes through the installation of new etching and lamination lines that are ideal for etching and pressing heavy copper PCB's without severe impact to productivity and throughput.

Delamination

Throughout the years, we have tested and perfected stackups and calculators that are instrumental in helping us to achieve the best of both worlds � keeping within the maximum thickness allowance while still pressing with enough resin to fill all voids.

Furthermore, our lamination presses use hot oil platens to ensure heat is applied uniformly across the entire production panel. This helps to guarantee and even cure across the panel, which is key to avoiding delamination.

Inner Layer Alignment

Generally, heavy copper PCB's are produced using thin core materials. Thin core materials are known to require varying degrees of scale factors to account for material shrinkage during lamination. Heavy copper PCB's are more prone to alignment issues that manifest themselves in the form of exposed copper in cutouts for windgs and along the edges of the PCBs. This is due in part to the larger window of etch factor that is common for heavy copper PCBs.

We have avoided this issue in large part to studying varying core materials in combination with copper retention percentages. A key instrument in these studies is the use of the PerfecTest system and resulting knowledge database. We consult this database each time a new part number is produced.

As a result of our extensive experience with Heavy Copper PCBs, we have achieved UL certification of up to 76 ounce copper for inner and outer layers. For non-UL requirements, we have produced up to 20 ounce copper PCBs!

For more information on Heavy Copper PCB click here: http://www.saturnelectronics.com/heavycopperpcb.htm