Matters Needing Attention In The Process Of PCB Lamination In Multilayer PCB

Matters needing attention in the process of PCB lamination in multilayer PCB

The total thickness and number of layers of a PCB multilayer board are limited by the characteristics of the PCB board. The boards with different thicknesses that can be provided by special boards are limited, so designers must consider the board characteristic parameters and the limitations of PCB processing technology in the PCB design process. Today, I will introduce the precautions for PCB multilayer lamination process, let's take a look!

Lamination is the process of bonding each layer of a circuit board into a whole. The whole process includes kiss press, full press and cold press. During the kiss press phase, the resin penetrates the bonding surface and fills the voids in the lines, before entering full press to bond all voids. The so-called cold pressing is to quickly cool the circuit board and keep the dimensions stable.

Matters needing attention in the lamination process, first of all, in terms of design, the inner core board that must meet the lamination requirements, mainly thickness, external dimensions, positioning holes, etc., needs to be designed according to specific requirements. In general, the inner core board Requires no open, short, open circuit, no oxidation, no residual film.

Secondly , in the design of the 8-layer circuit board , when laminating the multi-layer board, the inner core board needs to be processed. The treatment process includes black oxidation treatment and browning treatment. Oxidation treatment is to form a black oxide film on the inner copper foil, and browning treatment is to form an organic film on the inner copper foil.

In the final 8-layer circuit board design , we need to pay attention to three issues when laminating: temperature, pressure and time. The 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 of the heating rate. These parameters require attention. As for the pressure, the basic principle is to fill the interlayer cavity with resin and discharge the interlayer gas and volatiles. The time parameters are mainly controlled by pressurization time, heating time and gel time.

The above are the things we need to pay attention to in the process of laminating multi-layer PCB boards! Hope it can help you!