Complicated double-layer PCB manufacturing process
Double panels are usually made of epoxy glass cloth. Unlike the single-layer printed circuit board manufacturing process, the double layer PCB manufacturing process is a more complex process, and SMOBC is a typical process in the double layer PCB manufacturing process. The process is as follows:
Double-sided copper-clad laminate → blanking → stacking plate → CNC drill through-hole → inspection, deburring brushing → electroless plating (via metallization) → (full plate electroplated thin copper) → inspection, brushing → screen printing negative circuit Graphics, curing (dry film or wet film, exposure, development) → inspection, repairing → line pattern plating → electroplating tin (resistance nickel/gold) → de-printing (photosensitive film) → etching copper → (returning tin) → Cleaning and brushing → Screen printing solder resist pattern (adhesive dry film or wet film, exposure, development, heat curing, commonly used photothermal curing green oil) → cleaning, drying → screen printing character graphics, curing → (spray tin or organic insurance Solder film) → shape processing → cleaning, drying → electrical continuity test → inspection packaging → finished product delivery.
The key process description of double-layer PCB manufacturing process is as follows: 1 CNC drilling, 2 plated hole process, 3 imaging: Screen printing can also be used in double-layer PCB manufacturing process, its low cost can be mass-produced, but it is difficult to make low Fine wire and fine-distance double-panel below 0.2mm, so now the double layer PCB manufacturing process uses dry film imaging in one step, 4 electroplated tin-lead alloy: the typical process currently in PCB processing – double layer PCB manufacturing process It is a “graphic plating method”, 5 etching, 6 heat fusion hot air leveling, gold plating. The double-layer PCB manufacturing process is very strict in controlling the etching coefficient during the etching process. Usually, the double layer PCB manufacturing process uses a vertical jet type or a lateral protective agent to increase the etching coefficient at the etching stage.