Cream Solder Inspection Technology By Projecting Phase-shifted Fringes

The solder bonding is one of the most important elements of the high-density PUB mounting (packaging) process. As a result of the recent shift to surface mounting and further increase of mounting (packaging) density, being stimulated by the trend toward reduction of dimensions and weight of electronic devices, it is becoming more and more difficult to modify the solder joint after reflow process. Therefore strict quality control must be performed upstream in the production process. In order to ensure strict quality control in the cream solder print process the authors have developed a system which executes high-speed 3-dimensional contactless measurement of cream solder paste print profile and the in-line inspection of volume, profile, etc.