Displacement sensor The smoothness of the screen printed resistor (thick film resistor) is worse than that of the conductive plastic resistor made by pressing. Referring to the following pictures, we can see that the conductive plastic line produced by pressing process Displacement sensor The surface of the resistance film is smooth, but the surface of the resistance film of the displacement sensor printed by screen printing has fine particles. This is because the conductive plastic (DAP) of the pressing process is a thermosetting resin, and the carbon and graphite fuse after pressing at a certain temperature, so its surface is smooth, However, the carbon and graphite of the screen printed resistance film are solidified in the IR furnace, so sometimes some tiny particles on the surface can't be leveled, so the overall smoothness is not very good. But we can use the way of grinding the resistance film to remove the particles on the surface of the screen printed resistance film or the oxide layer formed on the surface of the resistance film during the curing in the IR furnace, It can make the surface of resistance film smoother and smoother, and also can improve the dynamic noise, as shown in the following picture
Conductive plastic resistance ruler resistor piece:
Screen printed potentiometer resistor:
Screen printed potentiometer resistor after grinding contrast picture:
Comparison of printed potentiometer resistor before grinding and after polishing
