Requirements for lamination technology of PCB multilayer boards

The design of a multi-layer PCB is different from that of a single-layer or double-layer board. It involves laminating multiple PP layers together, and also includes inner layer circuitry and etching. There are requirements for the line width and spacing of the inner layers, especially as the number of layers increases and the circuitry becomes denser, which in turn places higher demands on the processing capabilities of the manufacturing enterprise.

Lamination is the process of bonding each layer of a circuit board into a single unit. The entire process includes kiss lamination, full lamination, and cold lamination. During the kiss lamination stage, resin penetrates the bonding surface and fills the gaps in the circuit, followed by full lamination to bond all gaps. Cold lamination refers to rapidly cooling the circuit board to maintain dimensional stability.

Regarding the considerations for the lamination process, firstly, in terms of design, the inner core board must meet the lamination requirements, mainly regarding thickness, overall dimensions, positioning holes, routing, etc. The manufacturing enterprise should also strictly adhere to the customer's production needs.

Meanwhile, when we are laminating, we need to pay attention to three issues: temperature, pressure, and time. Temperature mainly refers to the melting temperature and curing temperature of the resin, the set temperature of the hot plate, the actual temperature of the material, and the change in heating rate. These parameters need to be paid attention to. As for pressure, the basic principle is to fill the interlayer cavities with resin and discharge the interlayer gas and volatiles. The time parameters are mainly controlled by the pressurization time, heating time, and gel time.