PCB Technical - High-precision eight-layer pcb circuit board processing flow

Processing flow of high-precision eight-layer PCB circuit board:

Eight-layer copper-clad board blanking, drilling benchmark holes, CNC drilling via holes, inspection, deburring, brushing, electroless plating (through hole metallization), electroplating of thin copper on the whole board, inspection, brushing, and screen printing of negative circuit patterns, Curing (dry film or wet film, exposure, development), inspection, repairing, circuit pattern plating, tin electroplating (anti-corrosive nickel/gold), printing material (photosensitive film), copper etching, tin stripping, cleaning, brushing, and mesh Soldering resist graphics (sticking photosensitive dry film or wet film, exposure, development, thermal curing, commonly used photosensitive thermal curing green oil) ~ cleaning, drying-screen printing marking character graphics, curing-shape processing, cleaning, drying-electrical communication Break inspection, spray tin or organic solder mask, inspect packaging, and leave the finished product.

As far as the process is concerned, the high-precision eight-layer PCB circuit board: printed circuit boards with patterns that have been made - acid degreasing - scanning water washing - secondary countercurrent washing - micro-etching - scanning water washing - secondary countercurrent washing - copper plating Dipping - copper plating - scanning water washing - tinning prepreg - tin plating - secondary countercurrent washing - lower board

There are vias and blind vias above eight layers. Vias are opened from the top layer to the bottom layer. Blind holes are only visible in one of the top or bottom layers, and the other layer is invisible, that is, blind holes. The hole is drilled from the surface, but not through all layers. There is another kind called buried via. Buried vias refer to vias in the inner layer, and the surface and bottom layers are invisible. The advantage of making buried vias and blind vias is that it can increase the wiring space

Eight-layer PCB circuit board wiring method: Generally speaking, the eight-layer PCB circuit board can be divided into a top layer, a bottom layer and two middle layers. The top and bottom layers are routed with signal lines. The middle layer first adds INTERNALPLANE1 and INTERNALPLANE2 with ADDPLANE through the command DESIGN/LAYERSTACKMANAGER as the most used power layer such as VCC and ground layer such as GND (that is, connect the corresponding network label.

Be careful not to use ADDLAYER, this will increase MIDPLAYER, which is mainly used for multi-layer signal line placement),

In this way, PLNNE1 and PLANE2 are two layers of copper connecting the power supply VCC and the ground GND.