The increase in PCB circuit density brings many benefits. In terms of circuit performance, the increase in circuit speed, the reduction in transmission distance, and the reduction in the space occupied by a single device shorten the time it takes for information to pass through the chip. This faster performance makes Nazhai once wait for the computer to complete a People who work simply can benefit a lot. The increase in circuit density also makes the chip or circuit consume less power. The ENIAC, which requires a small power station to maintain operation, has been replaced by a battery-powered, powerful portable computer.

There are basically three ways to increase the density of printed circuits:

1. Reduce the conductor line width and the spacing between them.

2. Increase the number of circuit layers in the PCB.

3. Reduce the size of vias and pads and the spacing of vias.

Reducing the conductor line width requires a very thin copper foil to obtain high yields in the circuit etching process. However, under other conditions being equal, the lower profile leads to reduced adhesion of the foil to the dielectric.

It is important to balance the copper surface profile to adhere to the dielectric and have the ability to etch fine circuit features, not to mention the effect of surface roughness on high-frequency electrical performance.

Consider that copper foil manufacturers continue to research methods to improve the chemical adhesion between the foil and the various dielectric materials used, while relying on mechanical surfaces less and strong adhesion, and allows extremely low profile circuits for circuits Etch and reduce conductor loss at high frequencies.

The increase in the number of PCB circuit boards leads to an increase in the overall multilayer thickness and a thinner thickness of a single dielectric, so thickness control and thermal reliability are more important than ever. Also adding layers to the PCB requires improved registration functions. A key variable that controls registration is the dimensional stability of the laminate material. As the number of layers increases, the dimensional stability of the laminate becomes more challenging. Reducing the size of the orifice and the spacers also needs to improve the dimensional stability of the laminate to match the high-level circuits, while the smaller the distance between the orifice and the orifice requires stronger thermally stable materials.