After the customer's plug-in test, it is found that the via hole (via hole) is not connected. The test can be carried out normally before the plug-in, and the appearance has no drilling deviation phenomenon, which is mainly caused by the following five reasons:

First: the hole copper is not enough;

Second: the roughness of the hole wall is too large

Third: Drilling dust plug holes

Fourth: drilling broken knife to make up holes

Fifth: poor solder mask plug hole

 In terms of controlling the problem of through-hole failure, the hole copper is the most important link. The automatic sinking copper line of our Honglian circuit is not small:

Detection: The detection method of immersion copper wire is mainly backlight series detection. The number of series is more than 9 to be qualified to ensure the quality of copper immersion and hole formation.

 The detection methods include deposition speed force detection (copper layer thickness in standard time); glue removal speed force (this is mainly for multi-layer boards that need glue removal); hole wall roughness detection