Multilayer PCB in today's electronics industry is also more and more widely used. Now, with the application of the computer gradually popular, because of the high functional demand, make the wiring capacity, transmission characteristics of FPC Multilayer board to focus on the demand.
It refers to the method of making multilayer PCB, it is usually done by the inner layer graphics first, then by printing etching method as single-sided or double-sided substrate, Multilayer PCB and into the designated Interlayer, then heated, pressurized and bonded. As a matter of fact, these basic production methods have not changed much from those of the 1960 's, but as materials and process technology become more mature, Multilayer PCB the characteristics of the attached multilayer board are becoming more diversified.
Compared to other forms of PCB, multilayer PCB can increase the number of wiring layer, thus increase the design flexibility, because of high assembly density, the connection between the components is reduced, thus improving the reliability. In addition, the device can also set up circuits, Multilayer PCB magnetic circuit shielding layer, as well as metal core heat dissipation layer to meet the shielding, heat and other special functions need. Of course, multilayer PCB is not completely without defects. High cost, long cycle, Multilayer PCB the need for high reliability of detection means, these costs above will require greater pay.
In short, with the development of electronic technology, especially the extensive and deep application of large scale and VLSI, multilayer PCB is rapidly developing to the high density, Multilayer PCB high precision and high level digital direction to meet the needs of the market, such as fine lines, small aperture penetration, blind hole buried hole and high plate thick aperture ratio.
The fabrication method of multilayer PCB includes steps: Providing copper foil formed on the surface of the off-type substrate and making the copper foil as a circuit, providing an insulating layer with a pass hole and metallization of the through hole. ; Multilayer PCB a plurality of circuits formed on the surface of the off-type substrate and a plurality of insulating layers with metallized through holes are alternately folded to form a predetermined layer of the pre-pressed circuit board, which makes the two relative surfaces of each insulating layer in the pre-compression circuit board combined with a single layer of wiring, Multilayer PCB And the two relative surface lines of the insulating layer are respectively covered by the metallization through hole in the insulating layer, and the pre compression circuit board is compacted to obtain multilayer PCB.