Copper Thickness FAQ

Copper thickness, which is the amount of copper a PCB contains, is usually expressed in ounces (oz), which is the most common unit of measure for copper. But how thick is that? It’s the thickness that results when 1 oz of copper is flattened and distributed over an area of one square foot. That comes out to 1.37 mils (1.37 thousandths of an inch). Not everyone thinks in mils but check the chart below to convert to whichever unit of measure you prefer.

1 oz Copper Thickness Conversi

1 oz copper thickness is the most common type of PCB. Unless there are specific specs provided to us, we will always assume 1 oz quoted and built at PCB Universe. If you have decided that your design requires more current than 1 oz is capable of handling, you will either need to increase the copper weight or widen your traces.

The thicker the copper the more expensive of course but quite often this is a must. That is welcome news, because not only are costs for raw materials increasing but it takes longer and is a little more tricky to process thicker copper weights. When you design your board, keep the following chart in mind. The more room at all you can give between copper features the better. It is harder to etch the spaces (air gap) between your traces, than it is to etch a space that is as wide as your trace.