What is the Difference Between Solder Mask Ink and Cover Film?

Have you ever encountered difficulties in choosing solder mask ink and cover film when designing PCB? Both the solder mask ink and the cover film have the function of protection and insulation. Do you know the difference between solder mask ink and cover layer?

Solder mask inks are generally green, black, white, red, yellow, blue, etc. Cover film are generally yellow, black and white. Compared with the cover film, the solder mask ink can have more choices in color, which can meet the color requirements. Black has good shading properties and white has high reflectivity. White solder mask ink is used for LED backlight, which is more common in flexible boards.

The solder mask ink has thin thickness, low insulation strength and poor bending performance. It is suitable for PCBs that require thinness and low flexibility. The cover film has thick thicker, good bending performance, high protection and insulation strength, and is suitable for PCBs with high insulation strength and high flexibility requirements.

Solder mask ink does not have the problem of glue overflow, which is suitable for small pitch pads. However, the cover film with glue will overflow when pressing, which is not suitable for small pads. The printing method adopted by the solder mask ink is simple to process and low in cost. The solder mask opening of the solder pad is generally done by drilling method. To realize the window opening of right angle, square and so on, it needs extra mould opening or laser cutting, which is more difficult and the total cost is higher.

HOYOGO is an international, professional and reliable PCB Manufacturer. We have a PCB design team with more than 12 years of work experience. The products we produce are rigid PCBs from 2 to 56 layers. At the same time, we can also provide FPC, HDI, and all other special PCBs. With our rich experience and technical understanding, as well as our own production capacity and local centralized resources, we can provide you with one-stop service from small, medium to mass production.