What are the most common problems when SMT patches are processed
SMT processing has become an essential technology of modern electronic industry, but continue to use the SMT technology in the electronics industry at the same time, often encounter problems can not be ignored, so when SMT processing the most frequently encountered problem what? Today we have a good understanding of up.
1, wire or trailing
Drawing or tailing is one of the most common defects of dispensing, the main reasons for these defects are produced because the dispensing pressure is too high, the PCB mud glue nozzle spacing is too large, too small diameter rubber mouth, patch delivery or quality of the adhesive patch is not good, the viscosity is too good, take out from the ice box after no return to room temperature began to use etc..
2. Plugging of glue mouth
The main block of this phenomenon is the glue glue mouth glue quantity is less, or no glue points out, most of the reasons for this situation is because the needle mouth is not completely clean or combination of incompatible glue, adhesive mixed with impurities are plugging etc..
3. Empty play
Playing mainly refers to only dispensing action, but not a coach, this is mainly because there are air patch glue, especially glue the situation pretended to more serious, in addition to replace the rubber mouth may be into the air, which is one of the main causes of air.
4. Displacement of components
One is the main components, the solid gel shift after the patch element, if the situation is serious situation, there may be no corner element on the pad, which is, the main reason is because when a mobile element or patch patch glue initial stick force is relatively low, or because the adhesive glue is not uniform, resulting in even a little glue a few cases, there is a little thick PCB if placed too long, will also appear solid glue gel caused by displacement of the element.
5. After curing, the pin is floating or shifted.
The main phenomenon is PC after curing, a pin float or displacement, but also serious circumstances such as open circuit short circuit, the main reason is because of the uneven distribution of patch glue, adhesive patch is too much or when already let the element displacement.
These five questions are in the process of SMT chip processing which is often seen, but this problem can be more than five, it also has several other small problems, but they also have to deal with their own means, if you are interested, you can continue to pay attention to this station, we will update from time to time at a later time, and related content.