Introduction to the Process of Printed Circuit Board Reduction Method

Printed circuit boards manufactured through subtractive manufacturing can be divided into the following two categories:

1. Non coated thick hole plate

This type of printed circuit board is produced by screen printing, etching the printed circuit board, or by photochemical methods. Non porous printed circuit boards are mainly single boards, with a few double boards, mainly used for televisions and radios. The following is the single board production process:

Single sided copper-clad board cutting, photochemical method/screen printing image transfer, removal of corrosion-resistant printing materials, cleaning and drying, hole processing, contour processing, cleaning and drying, printing solder mask coating, curing, printing marking symbols, curing, cleaning and drying, pre coating flux, drying finished products.

2. Printed circuit board with holes (electroplated through-hole board)

Chemical plating and electroplating are used to electrically connect the conductive patterns between two or more layers on the copper coated laminated board drilled. This type of printed circuit board is called a perforated printed circuit board. Perforated printed circuit boards are mainly used in computers, program-controlled switches, mobile phones, etc. According to different electroplating methods, it can be divided into pattern electroplating and full board electroplating.

(1) Pattern electroplating (Pattern. n, P'i'n) is used to form conductive patterns on double-sided copper-clad laminates through screen printing or photochemical methods. The conductive patterns are coated with corrosion-resistant metals such as lead tin, tin cerium, tin nickel, or gold, and then the resist except for the circuit patterns is removed and etched. Pattern electroplating can be divided into pattern electroplating and etching processes, as well as copper solder mask layer (SMOBC). The process of manufacturing double-sided printed boards using bare copper covered solder mask is as follows:

Material dropping, punching positioning holes, CNC drilling, inspection, hair removal, thin copper chemical plating, thin copper electroplating, inspection, brushing, film sticking (or screen printing), exposure and 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 testing, cleaning, solder mask patterns, plug nickel/gold plating, plug tape pasting, hot air leveling, cleaning

(2) Perform full plate electroplating (panel) on double-sided copper-clad laminates, copper plating to the specified thickness, and then transfer the image through screen printing or photochemical methods to obtain a corrosion-resistant positive phase circuit image. Then remove the resist and make the printed board.

The entire electroplating method can be divided into plug hole method and masking method. The process flow for producing double-sided printed boards using mask printing is as follows:

Double sided copper-clad board cutting, drilling, hole metallization, full board electroplating thickening, surface treatment, pasting, photomask dry film, making positive phase conductor patterns, etching, film removal, plug electroplating, contour processing, inspection, printing solder mask coating, solder coating, hot air leveling, printing mark numbers, and finished products.