There have been a lot of improvements and advancements in the printed circuit board technology. From manufacturing a PCB to deciding its board density, PCBs have seen a lot of developments, but the one thing that remains unchanged is the basic construction of a PCB. A printed circuit board can have a single layer, or it may vary from 1 to 20 depending upon the application for which it is designed. Twisted Traces is a leading manufacturer of PCBs, which provides PCBs in 1-20 layers (FR- 4, FR- 406, 370 HR), and in 1- 2 Layers (Rogers, Aluminum/Copper Base, Teflon). There are two main layers on any PCB. They are as follows:
- Inner Layers: Also referred to as internal layers in multilayer PCBs, the inner layers can be fabricated with a positive or negative polarity. Sometimes, inner layers employ copper pour technique, which helps a lot in layer to layer bonding process. The copper pour helps reduce the etchant during the PCB manufacturing process. The copper weight and thickness is customizable and depends on the application requirements. The weight of copper in the layer determines the minimum trace width and spacing that can be manufactured.
- Outer Layers: Outer layers are also known as external copper layers of a printed circuit board. These layers are used to attach electronic components either by surface mounting technique or soldering into the through holes. The outer layer consists of a copper foil, which is electroplated with copper. This is basically done to increase the thickness and add copper to the through-hole barrels. The thickness of the finished copper is customizable depending upon the application requirements.