PCB material appearance defects common measures and industry analysis of commonly used terms
The reason PND (Pits and Dents) pits and depressions occur: fish any fines particles adsorbed by the edges due to static electricity, the upper plate residual water Material of the active air drop of dust and debris attached to the copper plate. Solution: identify the problem immediately to re-grind plate and, after washing on the line of the most fundamental solution to reduce staff contact and exposure to air time, to complete the clean room stacked combination of cutting and automatic installation of devices to eliminate static electricity.
SLP (Slippage) slip occurs: piece of content R / C high and flow R / F is greater than the pressure is too easy to produce timely, and every pot temperature is too large and cause uneven flow substrate per pot Chan will lead to poor positioning piece slip responses: Chan piece R / C, R / F high vertical machine (or water Liquidation machine) can also alter the conditions on Chan laminated CYCLE such as reduced heating rate as amended, postponed the pressure, reduce stress, if a larger temperature difference between each pot can reduce tension lowering capacity to overcome the poor pay more attention to improving the positioning operation.
Dry (Dried Laminate) board dry Analysis: Poor glass cloth coupling agent compatibility with resin resulting in poor wetting. Or piece over so that timely pressure hardening resin flow is bad if found to have low flow pcb board that will produce dry, this condition at the time of solder measured prone stratification. Solution: glass cloth surface finish problems, please materials manufacturers improved low traffic reduces varnish water of time or improve piece flow of time and, if not serious Dry Lamination may amend conditions such as increased temperature rate, the pressure on early, increasing pressure.