LEAPPCB will teach you how to distinguish the positive and negative of PCB

How to distinguish between positive and negative piece of PCB circuit board film usually (without the word) to give you a line (copper surface), or green oil film (resistance welding) PCB you are positive and negative points out, distinguish PCB film characters.Because the character one picked up, the word is positive it's positive, the word is negative, it's the opposite.

There are two ways of distinguishing between the line and the green oil

The first is to use the characters to make sure that there is a positioning hole in the PCB film, and the front of the character can be used to find the front and back of the line with the green oil.

Second, in the absence of PCB film characters, film cutter with PCB, the PCB film of large Angle of line above or online gently a bit, can see blew it to, if I could have to go to is positive, otherwise it is opposite.

So it's the same plane that separates the line from the oil.In the end, we need to find the character PCB film, or the sample data printed by the computer, or PCB film materials.