PCB copy board common obstacles
A net, etching is not caused by the PCB short circuit 1, etching liquid parameter control is good or bad directly affect the quality of etching. Second, visual PCB micro short circuit, exposure machine Myra 1 film scratch lines caused by micro short circuit; 2, exposure plate glass scratch lines caused by micro short circuit. Three, run tin the PCB short circuit 1, retired film cause run tin plate stacked together; 2, in the medicine tank back membrane improper operation caused run tin. PCBA SMT four, fixed position of PCB circuit have scratches or short circuit the main reason is that film coated on the screen with junk clogging, the coating resistance coating fixed dew copper cause a short-circuit. Five, the invisible invisible micro short circuit PCB micro short circuit for our company, is the most long used to be the hardest problem to solve, also in the finished product plate of the problems in the test, about 50% is belongs to the problem of this kind of micro short circuit, the main reason is the line spacing exists within the naked eye cannot see wire or metal particles. Six, the capsule PCB short circuit 1, resistance of coating layer is too thin, electroplating for coating is beyond the film thickness, forming film, especially the smaller spacing between easy to cause the capsule short circuit; 2, uneven distribution of graphic panel, isolated a couple of lines in a graphical electroplating process, due to the high potential, coating beyond film thickness, the formation of membrane caused by short circuit. Seven, scratch PCB short circuit 1, developing machine export board hands are full plate and plate collision between scratch; 2, coated wet film scratches, after the matchups improper operation cause scratches at the membrane surface; 3, plating board is undeserved, splint on improper operation, manual processing line before the board improper operation and cause scratch.