SMT Process Flow of FPC

Here we use the ordinary carrier board as an example to illustrate the Surface Mounted Technology (hereinafter referred to as the SMT ) points of flexible printed circuit (hereinafter referred to as the FPC). When using silica gel board or magnetic fixture, the fixing of FPC is much more convenient, no need to use tape, and the process points of printing, patching and welding are the same. 

1. FPC fixation:

Before performing SMT, it is first necessary to accurately fix the FPC on the carrier board. It is important to note that the shorter the storage time between printing, placement and soldering after the FPC is attached to the carrier, the better.

2. FPC solder paste printing:

FPC does not have any special requirements on the composition of the solder paste. The size and metal content of the solder ball are based on the fine pitch IC on the FPC. However, the FPC has high printing performance requirements for the solder paste, and the solder paste should have excellent properties. In terms of thixotropy, solder paste should be able to print off the mold easily and firmly adhere to the surface of the FPC, without the problem of poor mold release, clogging of the steel mesh, or collapse after printing. 

3. FPC patch:

According to the characteristics of the product, the number of components and the efficiency of the placement, it can be mounted by medium and high speed placement machines.

4. FPC reflow soldering:

A forced hot convection infrared reflow oven should be used so that the temperature on the FPC can be changed more evenly, reducing the occurrence of poor soldering.

1). Temperature curve test method: