The aluminum substrate is a metal-based copper-clad plate with good heat dissipation function. Generally, the single-sided board is composed of a three-layer structure, which is a circuit layer (copper foil), an insulating layer, and a metal base layer. Aluminum substrates are rarely made into double-sided circuit boards, and double-sided circuit boards will affect its heat dissipation and other functions. Aluminum substrates are commonly used in LED lighting, such as: industrial led light boards, automotive car light boards, medical surgery LED light boards, display screen led light boards and so on. The aluminum substrate has both front and back sides. Usually the back side is unpackaged and presents the true color of aluminum. On the other side, the white side is soldered to the LED pins. Generally, the thermally conductive paste is applied to the thermally conductive part after contact. There are ceramic substrates and so on.