Glue overflow is a relatively common quality anomaly in the FPC soft plate pressing process. Glue overflow refers to the problem that the glue system in COVERLAY flows due to the rise of temperature in the pressing process, resulting in glue stains similar to EXPORY series at the PAD position. There are many reasons for the overflow. What are the specific reasons? Let's talk about it in detail.

Reasons for glue overflow

1. Glue overflow is caused by COVERLAY manufacturing process

Then, the FPC FPC manufacturer should strictly inspect the incoming materials. If the overflow exceeds the standard during the sampling inspection of incoming materials, contact the supplier to return and replace the goods. Otherwise, it is difficult to control the overflow during the production process.

2. Glue overflow is caused by storage environment

FPC flexible circuit board manufacturers should establish special refrigerators to store the protective film. If the CL glue system is affected by moisture due to unsatisfactory storage conditions, low temperature can be used to pre-bake the CL to greatly improve the CL glue overflow. In addition, CL that is not used up on the same day should be put back in the freezer for storage in time.

3. Local glue overflow caused by independent small PAD position

This phenomenon is one of the most common quality abnormalities encountered by most FPC FPC manufacturers at present. If the process parameters are changed simply to solve the overflow, 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 mode

When the FPC flexible circuit board is falsely connected, it is required to require the staff to accurately align, correct the alignment fixture, and increase the inspection of alignment to avoid glue overflow due to inaccurate alignment. At the same time, do a good job of "5S" during crimping and false connection. Before alignment, check whether the protective film CL is contaminated and whether there are burrs.

5. Glue overflow caused by plate factory process

If the fast press is used for pressing, properly extending the pre-pressing time, reducing the pressure, reducing the temperature, and reducing the pressing time will help to reduce the amount of glue overflow. If the pressure of the press is uneven, you can use the induction paper to test whether the pressure of the press is uniform, and you can contact the fast press supplier to debug the machine equipment.