... 3)Good after-sale service Controllers for 1in1 Air conditioner pcba factoryPCBA specific instructionMaterial:FR-4Layer: 2 layersSurface ... Gold plating, Chemical silver, etc.The other solder mask type we could do are: Red, yellow, white, black ... OEM&ODMkinds of pcba manufacturedPCBA service: medical, instrument, environmental, industrial, networking, automotive, aeronautics, security and other ...