1. With the gradual development of electronic products, which are becoming shorter, smaller, lighter, and thinner, the advantages of FPC flexible boards are very obvious, and the market demand is also increasing. However, due to the mass production process of flexible boards, defects in the boards are often caused by improper operation. Here, I have compiled a list of 10 common problems. Let’s take a look.
10 Common Problems of FPC Flexible Board Surface Defects
1. Bubble
Bubbles appear on the FPC printed board between the lines or on a single line side after development. The main reason for this is that bubbles occur between two or more lines primarily due to the line spacing being too narrow and the lines being too high, which prevents the proper printing of the solder resist onto the substrate during screen printing. This results in the presence of air or moisture between the solder resist and the substrate, leading to gas expansion during curing and exposure to heat. Bubbles on single lines are mainly caused by the lines being too high. When the squeegee contacts the line, if the line is too high, the angle between the squeegee and the line increases, preventing the solder resist material from being properly printed to the root of the line. This causes the presence of gas between the side of the root of the line and the solder resist layer, resulting in bubbles during heating. The solution is as follows: during screen printing, visually inspect to ensure that the screen printing material is completely printed onto the substrate and the side wall of the line. During plating, strictly control the current.
10 Common Problems of FPC Flexible Board Surface Defects
1. Bubble
Bubbles appear on the FPC printed board between the lines or on a single line side after development. The main reason for this is that bubbles occur between two or more lines primarily due to the line spacing being too narrow and the lines being too high, which prevents the proper printing of the solder resist onto the substrate during screen printing. This results in the presence of air or moisture between the solder resist and the substrate, leading to gas expansion during curing and exposure to heat. Bubbles on single lines are mainly caused by the lines being too high. When the squeegee contacts the line, if the line is too high, the angle between the squeegee and the line increases, preventing the solder resist material from being properly printed to the root of the line. This causes the presence of gas between the side of the root of the line and the solder resist layer, resulting in bubbles during heating. The solution is as follows: during screen printing, visually inspect to ensure that the screen printing material is completely printed onto the substrate and the side wall of the line. During plating, strictly control the current.