The circuit board sheet in aluminum can perfectly solve the problem of heat dissipation of a PCB with various thicknesses. When punching entry sheet for printed circuit board, it must be remembered that these materials are elastic and this tendency to spring back will make the punched holes slightly smaller than the punch. Aluminum entry sheet is a metal-based copper clad laminate with good heat dissipation function. Generally, a single-sided panel consists of three-layer structure, which are circuit layer (copper foil), insulating layer and metal base layer. For high-end use, there are also double-sided designs with a structure of circuit layer, insulating layer, aluminum base, insulating layer, and circuit layer. Very few applications are multi-layer boards, which can be made by laminating ordinary multi-layer boards with insulating layers and aluminum bases.
The heat dissipation and thermal conductivity of aluminum circuit board sheet are high, and the heat generated by the PCB aluminum substrate chip can be quickly conducted outward through the aluminum substrate. Both the aluminum entry sheet substrate and the chip substrate are made of AL2O3 material, with similar expansion coefficients, and will not cause die welding due to temperature changes, resulting in attenuation and dead lights, ensuring the stability of the chip.
With the development trend of PCB multi-layer, multi-layer, functional, integrated and light, thin and short, the hole diameter of PCB drilling is getting smaller and smaller, the density is getting higher and higher, and the drilling accuracy and requirements are getting higher and higher. The functional assistance of the circuit board sheet to the mechanical drilling will be more and more important, and it will gradually be recognized and accepted by everyone. At the same time, as the aperture becomes smaller, in addition to the hardness and density affecting the drilling performance, other properties of the backing plate such as warpage, apparent quality, surface roughness, thickness uniformity, etc. will also affect the drilling performance. Therefore, the quality and requirements of the backing plate will be higher and higher in the future.