Keywords: screen printing, pcb
Pre-treatment of specific operations and Notes (1) pre-soaking water, the purpose is to wash away the copper impregnated on the surface impurities and wetting of copper levels in order to accelerate the speed of pickling time, should we do control the transmission speed of the machine, too slow for the transmission of the machine, will over-lapping copper surface.
(2) pickling acid is a 5 ~ 10% sulfuric acid solution for spraying, the time limit of 1 minute. Acid to remove the board, the main chemical impurities
And make minor micro-etching of copper surface. Check before operating the nozzle is blocked, so as not to spray in some places not affect the acid effect. After the pickling solution with the city of water will wash.
(3) brush scrubbing brush plate machine mesh is divided into two 300 mesh and 500 mesh. Purpose of using the 300 brush first, coarse, thick brush of the brush roller pressure to control at 2.2 below, it is not to make the surface of the substrate and the copper layer can not be accepted by the scratch, which will affect the appearance of PCB surface. 500 purposes then fine brush,
At this point the brush roller to control the pressure between 2.4 and 2.5, thin brush to make the Shuahen density board, so to make solder and mechanical action between board increase. Brush board's role is mechanical scratch plate surface dirt while coarse copper surface. Before the operation to open water fountain, but also regular inspection nozzle, spray pressure to ensure that, this reduces the nylon on the board and the hole of the pollution, while extending the life of nylon brush rollers.
(4) high-pressure washing pressure washing pressure to keep 12.5bar above, the pressure gauge can be seen in the actual operation that is not enough
Nozzle flow will directly affect the role and the actual pressure plate surface. There are high-pressure washing water is not circulating water, circulating water to yield good results. High-pressure washing is to wash away after the copper brush plate to avoid plate surface insulation resistance not affect the board's conductive properties, the operator in the next plate to check whether the copper plate surface, we go to solve as soon as possible.
(5) squeeze rollers squeeze water brush water generally used three sets of trigger squeeze the water roll, squeeze roll is the role of water through the high-pressure water washing after the printing plate board surface water drain, through the crowd with water (6) cold dry cold dry main role is to blow out the water hole, in order to avoid hot air drying section to form a new oxide board points. Board should be the upper hand after cold dry air knife on the board first blown, it avoids the formation of the plate hole oxidation drop points, but also to prevent the card board
It does not affect the production schedule.
(7) hot air drying in the drying section of the temperature control between 75 ~ 85 ℃, hot air dryer to dry surfaces and holes to the water vapor, in order to avoid solder screen printing, the ink adhesion is not enough.
This carried over: http://database.texnet.com.cn/db-technology/detail--308.html