The total thickness and number of layers of the PCB multilayer board are limited by the characteristics of the PCB board. Special boards are limited in the thickness of the board that can be provided, so the designer must consider the board characteristics of the PCB design process and the limitations of PCB processing technology.
Multi-layer compaction process precautions
Laminating is the process of bonding each layer of the circuit board into a whole. The whole process includes kiss pressure, full pressure and cold pressure. During the kiss pressing stage, the resin penetrates the bonding surface and fills the voids in the line, then enters full pressing to bond all the voids. The so-called cold pressing is to cool the circuit board quickly and keep the size stable.
Laminating process needs to pay attention to matters, first of all in the design, must meet the requirements of the inner core board, mainly thickness, shape size, positioning hole, etc., need to be designed in accordance with the specific requirements, the overall inner core board requirements no open, short, open, no oxidation, no residual film.
Secondly, when laminating multilayer boards, the inner core boards need to be treated. 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 brown treatment is to form an organic film on the inner copper foil.
Finally, when 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 of the heating rate. These parameters need attention. As for pressure, the basic principle is to fill the interlayer cavity with resin to expel the interlayer gases and volatiles. The time parameters are mainly controlled by pressure time, heating time and gel time.
Post time: Feb-19-2024
