Method for surface treatment by developing machine after electronic circuit board anti-soldering process

Abstract

The invention relates to a method for carrying out surface processing on an electronic circuit board (PCB) by a developing machine after welding prevention processing, which comprises the following procedures of processing by a first developing trough, primary wind pressure tube water prevention, processing by a second developing trough, secondary wind pressure tube water prevention, processing by a third developing trough, tertiary wind pressure tube water prevention, medium pressure washing, processing by a punching water jet scalpel, composite washing, processing by a sponge roller, cold air drying, hot air drying, inspection and the like. In the invention, after spray disks of the developing troughs are structurally regulated and the punching water jet scalpel is added, no residual ink is generated at the bottom of a blink hole and no phenomenon of poor hole blockage of a through hole is generated; by a wind pressure water prevention mode, the defect that after the ink is rolled by the roller, the copper surface of the PCB is stained with the ink can be improved and the amount of printing ink on pad can be reduced; the water using amount can be saved; the speed of the developing machine can be improved, the production efficiency is promoted, the scrappage is reduced and the yield rate of the PCB can be promoted.

Description

technical field [0001] The invention relates to a method for surface treatment of an electronic circuit board (PCB) after the anti-soldering process by using a developing machine, and specifically belongs to the technical field of PCB production and manufacturing. Background technique [0002] In the solder mask process of the circuit board (PCB) industry, it is necessary to print all the PCB boards with ink first. In the exposure process, the part of the ink used for the solder mask in the SMT process is exposed and polymerized by UV. In the SMT process, copper pads for welding parts are required. Or the hole ring of the inserted part does not do UV exposure. Through the principle that the ink without exposure polymerization can be dissolved into weak alkali, the exposed PCB is developed by the developing machine in the way of roller transmission, and through the principle that the ink can dissolve into weak alkali, the developing machine is equipped with 0.8-1.2% concentra...

AI Technical Summary

Problems solved by technology

[0019]1. There are a total of 19 nozzles arranged on the spray plate, and the height from the nozzle to the PCB surface is 19CM. The arrangement of the spray plate is unreasonable, and the spraying is uneven. The surface distance is too large and the spray pressure is insufficient, resulting in the ink at the bottom of the blind hole cannot be developed cleanly and the 13.8mils through hole is blocked, resulting in scrap

Insufficient developing nozzles, slow developing speed and insufficient efficiency

[0020] 2. The solid water blocking roller driven by the developing line will stain the developed ink chips on the copper surface, causing SM ON PAD on the copper surface

[0021] 3. The water washing pressure of the new developing solution is insufficient, and the residual sodium carbonate solution on the surface of the developing tank cannot be thoroughly cleaned, and a small amount of sodium carbonate solution will be brought into the high-pressure washing and composite washing sections of the rear section, resulting in crystallization in the washing section, resulting in Dirty PCB surface

[0022] 4. Due to the poor configuration of the developing machine, it will cause scrapping defects such as unclean copper surface, ink plugging, SM ON PAD, ink residue at the bottom of blind holes, etc., which will affect PCB yield

Slow developing speed and insufficient efficiency

[0023] 5. The pressure of the first water washing in the developing tank is insufficient, and a small amount of sodium carbonate solution will be brought into the high-pressure water washing and compound water washing sections of the rear section, which will cause water washing pollution. After washing pollution, it is necessary to increase the overflow flow of compound water washing and increase the amount of pure water