Why Does The FPC Pressing Process Overflow Glue

1. First, let's understand what is overflow glue


Bubbles and glue overflow are a common quality anomaly in the flexible circuit board lamination process. The glue overflow refers to the temperature increase in the lamination process that causes the glue system to flow in the coverlay, resulting in the FPC line PDA There is a glue stain problem similar to EXPORY series.


2. Let's discuss the causes of underflow glue

 There are many reasons for the overflow of glue, and it is related to the processing process of the protective film (COVERLAY). It is related to the process parameters of the FPC process, the preservation environment, and the operation mode of the employees. Below, we will discuss from specific factors.


1) One of the specific factors that produce overflow glue: it is determined by the parameters in the COVERLAY manufacturing process.


2) When CL is coated (COATING) and then enters the drying stage, if the temperature, time and other parameters are not properly controlled, it will lead to excessive flow of the glue during the semi-curing process. In addition, if the distribution of the CL glue system is uneven, it is difficult to control the amount of glue spill during the lamination process.

When such products are shipped to the customer first, the amount of glue spilled during incoming inspection will be significantly higher than the indicated value on the product specification.