Overflow glue is a common abnormal quality phenomenon in FPC flexible circuit board bonding process. Overflow glue refers to the glue system flowing in COVERLAY due to the increase of temperature in the bonding process, which leads to glue problems similar to EXPORY series on the PAD bit of FPC flexible circuit board. There are many reasons for FPC flexible circuit board glue overflow, so we should put forward different solutions according to the specific situation.

　　1. Glue overflow is formed in the process of COVERLAY production.

　　Then, FPC flexible circuit board manufacturers should strictly inspect the incoming materials. If the glue overruns in the incoming sampling inspection, contact the supplier to return the goods. Otherwise, it is difficult to control the glue overruns in the production process.

　　2. Glue spill is formed by storage environment

　　FPC manufacturers of flexible circuit boards should set up special refrigerators to preserve the protective film. If the CL adhesive system is damp due to unsatisfactory storage conditions, low temperature pre-drying of CL can improve the overflow of CL to a large extent. In addition, for the demand of CL not used up on that day, it should be put back into the refrigerator in time for preservation.

　　3. Partial glue overflow caused by small independent PAD sites

　　This phenomenon is one of the most common quality abnormalities encountered by most FPC flexible circuit board manufacturers in China. If the process parameters are changed simply to solve the problem of rubber spill, it will bring new problems such as bubbles or insufficient peeling strength, so the process parameters can only be adjusted reasonably.

　　4. Glue overflow caused by operation method

　　When FPC flexible circuit board super fake connection, it is necessary to seek accurate alignment of employees, proofread alignment fixture, and increase the inspection of alignment to avoid glue spill due to alignment prohibition. At the same time, "5S" operation should be done well when pressing false joints. Before alignment, it is necessary to check whether the protective film CL is contaminated and whether there are any fur edges.

　　5. Rubber spill caused by FPC flexible circuit board plant process

　　If fast press is used in pressing, proper extension of pre-pressing time, reduction of pressure, reduction of temperature and reduction of pressing time are beneficial to reducing overflow. If the pressure of the press is not uniform, can use induction paper to test whether the pressure of the press is uniform, can contact the fast press supplier to adjust the machine equipment.

The article originated from Jiangmen single-sided and double-sided circuit boards. http://www.yonghongpcb.com/