Is there an underfill glue factory, can you talk about the general steps of using the product?

PCB board chip underfill dispensing process steps: baking - preheating - dispensing - curing - inspection.

PCB board chip underfill dispensing processing.

It is a kind of special underfill glue to underfill some chips on the PCB board, so as to achieve the purpose of bonding and stability, and enhance the drop resistance between the chip in BGA packaging mode and the PCBA (finished board).

PCB board chip underfill dispensing processing.

PCB board chip underfill dispensing processing is mainly used for the underfilling of CSP BGA of PCB board, the dispensing process has good operability, easy maintenance after dispensing processing, impact resistance, drop resistance, and seismic performance, which improves the stability and reliability of electronic products to a certain extent.

Underfill process steps: baking - preheating - dispensing - curing - inspection. Hans Chemical recommends that the underfill baking process be kept between 120-130°C, as too high a temperature will directly affect the quality of the solder balls.

The specific steps for using underfill are as follows:

1.During the setting of the equipment, ensure that no air is introduced into the product;

2.For best results, the substrate should be preheated (typically 40 for about 20 seconds) to speed up capillary flow and promote leveling;

3.at the right speed (sizing. Make sure that the distance between the tip and the edge of the substrate and chip is to ensure optimal flow of underfill;

4.The way of sizing is generally:"i"type along one side or"l"The type crosses at the corners along the two sides. The starting point of sizing should be as far away from the center of the chip as possible to ensure that there are no voids in the filling of the chip.

When sizing"i"type or"l"The length of each strip of glue should not exceed 80% of the chip;

Underfill glue is simply the meaning of underfilling, the conventional definition is a kind of chemical glue (the main ingredient is epoxy resin) to underfill the chip of BGA packaging mode, and use the curing form of heating to fill a large area of BGA bottom void (generally covering more than 80%), so as to achieve the purpose of reinforcement and enhance the drop resistance between the chip and PCBA in BGA packaging mode. There are also some unconventional uses of underfill, which is to use some cyanoacrylate or room temperature curing glue to fill the corners or parts of the corners of the BGA packaging mode chip, so as to achieve the purpose of reinforcement.

Underfill is a high-flow, high-purity, one-component epoxy potting material. It can fill the bottom of CSP and BGA chips through innovative capillary action, and form a firm filling layer after heating and curing, which reduces the stress impact caused by the difference in thermal expansion coefficient between the chip and the substrate, improves the structural strength and reliability of components, and enhances the drop resistance between the chip and the PCBA in BGA mode.

KY underfill, at room temperature that has good fluidity, small filling gap, fast filling speed, can be quickly cured at a lower heating temperature, can be compatible with most lead-free and tin-free solder paste, can be reworked operation, with excellent electrical and mechanical properties.

Underfill adhesive is generally used in mobile phones, Bluetooth devices, cameras, temperature measuring instruments, POS machines, etc.

The application principle of underfill glue is to use capillary action to make the glue flow quickly through the bottom of the BGA chip, and the minimum space for capillary flow is 10um.