Before talking about the common problems of red glue, we can briefly understand red glue. Red glue (a single-component epoxy resin adhesive that cures quickly after being stored at room temperature and can be cured at low temperatures) is often used in patch processing and production because of its viscosity, fluidity, temperature characteristics, and wetting Features and other features can make the parts adhere firmly to the PCB board to prevent them from falling, so its usage rate is relatively high.

However, it is inevitable that you will often encounter some problems when using it. The following Sanjing will show you how to understand.

First of all, the first point is insufficient thrust. The reasons for insufficient thrust are mainly due to the following reasons: ①The amount of glue is too small or the glue is not completely cured; ②PCB boards or components are contaminated; ③The quality of the glue itself (no strength) .

The second is insufficient glue or leaks. The reason for this problem may be: ①The preheating temperature of the dispensing head is not enough; ②There are impurities or bubbles in the colloid; ③The opening of the screen is unreasonable, the aperture is too small or the dispensing pressure is too small; ④The dispensing head is blocked , The glue nozzle should be cleaned in time; ⑤ The screen used for printing is not cleaned regularly.

The third is the problem of wire drawing. The main reason for this problem is that the patch glue is not disconnected during dispensing, and the patch glue is connected in a thread when the dispensing head moves. If there are more wires, the patch glue covering the printed pads will cause poor soldering. This phenomenon is more likely to occur when using larger size dispensing nozzles. The wire drawing of the patch glue is mainly affected by the main component resin wire drawing. The influence of sex and the setting of dispensing conditions. The best solution at this time is to reduce the moving speed, and low viscosity, high thixotropy materials should also be selected in the selection of the patch adhesive, so that the wire drawing phenomenon is not easy to occur.

The above is about the common problems of red glue in SMT patch, I hope it can be helpful to everyone!