A Design Method of Text Missing and Anti-fooling Test Points

Abstract

The invention provides a method for designing text skip printing fool proof test points. The method comprises the following steps: 1) making two copper pad test points on the copper layer of the outer layer circuit of a circuit board, with the two copper pad test points connected by wires; 2) etching off the copper around the two copper pad test points and the wires linking the two copper pad test points to form an isolation ring; 3) conducting solder mask treatment on the circuit board, and conducting solder mask and opening windows above the two copper pad test points and the wires, with the two copper pad test points covered by no solder mask ink; 4) processing text on the circuit board, and opening text windows above the two copper pad test points, with the two copper pad test points fully covered by text printing ink. The method can completely solve the problem that the characters of the test points are virtually printed to uncover copper due to the small pressure at screen printing, so that marketing of PCBs with text skip printing is completely eradicated, the effective use of fool proof test points is guaranteed, and the reject ratio of products is reduced.

Description

technical field [0001] The invention relates to the technical field of circuit board detection, in particular to a method for designing a text missing-print proof test point. Background technique [0002] At present, the industry detects the problem of missing text in silk screen printing, and generally adds fool-proof test points to the production board for detection, and confirms whether there is a short circuit between the test points through electrical testing to determine whether the production board has missing text, thereby avoiding missing printing The production board of the text flows into the client; [0003] With the development of precision products, the spacing between characters and fonts are getting smaller and smaller. In order to avoid blurred silk screen text, the screen printing pressure is also reduced. At this time, due to the small screen printing pressure and the copper The pad area is affected by the height difference (generally in the range of 15um...

AI Technical Summary

Problems solved by technology

[0003] With the development of precision products, the spacing between characters and fonts are getting smaller and smaller. In order to avoid blurred silk screen text, the screen printing pressure is also reduced. At this time, due to the small screen printing pressure and the copper The pad area is affected by the height difference (generally in the range of 15um-25um), the test point cannot be fully covered by the text ink, resulting in virtual printing, which leads to the short circuit of the test point during electrical testing. leak purpose

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