Printed circuit boards manufactured by the reduction process can be divided into the following two categories:

1. Non plated thick orifice plate

The printed circuit board is produced by screen printing, then etching the printed circuit board, or photochemical method. Perforated printed boards are mainly single boards, and there are a few double boards, which are mainly used for TV sets and radios. The following is the board production process:

Blanking of single-sided CCL, photochemical method/screen printing image transfer, removal of anti-corrosive printing materials, cleaning and drying, hole processing, contour processing, cleaning and drying, printing solder barrier coating, curing, printing mark symbols, curing, cleaning and drying, precoating flux, drying finished products.

2. Hole printed circuit board (electroplated through hole board)

Electroless plating and electroplating are used to connect conductive patterns between two or more layers on the drilled copper clad laminate. This kind of printed circuit board is called perforated printed circuit board. Perforated printed boards are mainly used for computers, program-controlled exchanges, mobile phones, etc. According to different electroplating methods, it can be divided into pattern electroplating and full plate electroplating.

(1) Pattern electroplating (Pattern. n, P'I'n) On the double-sided copper clad laminate, a conductive pattern is formed by screen printing or photochemical method, and the conductive pattern is plated with corrosion-resistant metals such as lead tin, tin cerium, tin nickel or gold, and then the corrosion inhibitor other than the circuit pattern is removed and etched. Pattern electroplating can be divided into pattern electroplating and etching processes and solder mask on copper (SMOBC). The process of using bare copper to cover solder mask to make double-sided printed boards is as follows:

Blanking, punching locating holes, CNC drilling, inspection, hair removal, thin copper electroless plating, thin copper electroplating, inspection, brushing, film pasting (or screen printing), exposure development (or curing), inspection, correction, copper pattern electroplating, tin lead alloy pattern electroplating, film removal (or printing material removal), inspection, correction, etching, lead and tin removal, open circuit test, cleaning, solder resistance pattern, plug nickel/gold plating, plug tape, hot air leveling Cleaning

(2) Full plate electroplating (panel) is carried out on the double-sided copper clad plate (CCL) to the specified thickness, and then the image is transferred through screen printing or photochemical method to obtain the corrosion resistant normal circuit image, and then the corrosion inhibitor is removed to make the printed board.

The whole electroplating method can be divided into plug hole method and masking method. The process flow of mask making double-sided printing plate is as follows:

Blanking, drilling, hole metallization, full plate electroplating thickening, surface treatment, pasting, mask dry film, making normal conductor pattern, etching, film removal, plug electroplating, contour processing, inspection, printing solder resistance coating, solder coating, hot air leveling, printing mark number, and finished products.

The printed circuit board method has the advantages of simple process and good uniformity of coating thickness. The disadvantage is that it wastes energy, and it is difficult to manufacture printed boards without via connection pads.