Common problems and solutions during UV glue dispensing process
2021-07-19 3525
In the actual operation of UV glue, the quality of dispensing directly affects the effectiveness of UV glue use.
1. Drawing/Trailing
Wire drawing/trailing is a common defect in UV glue dispensing, which can be caused by small inner diameter of the nozzle, high dispensing pressure, large distance between the nozzle and the PCB, expired or poor quality of the adhesive, high viscosity of the adhesive, and excessive dispensing volume.
Solution: Replace the rubber nozzle with a larger inner diameter; Reduce dispensing pressure; Adjust the "stop" height; Change the adhesive and choose a UV adhesive with appropriate viscosity; Adjust the dispensing amount.
2. Air strike
The phenomenon of empty tapping is that there is only a dispensing action, but no glue output. The reason for this is that UV glue mixed with bubbles; The glue nozzle is blocked.
Solution: The UV glue in the injection cylinder should undergo defoaming treatment; Replace the glue nozzle.
3. Glue nozzle blockage
The fault phenomenon is that the amount of glue produced by the nozzle is insufficient or there are no glue points produced. The general reason for this is that the needle hole is not completely cleaned; Impurities mixed in the glue, resulting in clogging of holes; Mixing insoluble glue.
Solution: Replace with a clean needle; Replace with high-quality UV glue.
4. Components float/shift after solidification
The phenomenon of this fault is that the components float or shift after solidification, and in severe cases, short circuits or open circuits may occur. The main reasons for this are uneven glue and excessive amount of glue.
Solution: Adjust the dispensing process parameters; Control the amount of glue applied.
Yue Gong Wang An Bei No. 4419002005671