A kind of electroless copper backlight test method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NO 771 INST OF NO 9 RES INST CHINA AEROSPACE SCI & TECH
- Publication Date
- 2016-08-24
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Abstract
Description
technical field
[0001] The invention relates to hole metallization of printed circuit boards, in particular to a method for testing chemical immersion copper backlight. Background technique
[0002] The backlight test is used to test the coverage of chemical copper on the hole wall. It is a destructive test. It is necessary to cut the through hole from the section, pass a strong light through the back of the hole, and observe it from the front under a low magnification glass. The deposition of the copper layer on the hole wall, the place where the copper has been deposited will not transmit light, and the area where the copper is not deposited will have light passing through, so it can be graded by the number of bright areas seen to identify chemical The quality of copper deposition.
[0003] 4.2.3 of QJ2860-96 "Technical Requirements for Metallization of Printed Circuit Board Holes" stipulates the backlight inspection method: drill no less than 3 process holes with a diame...