Accompanying quality assurance for high level processing of advanced packages

In current electronics production, the quality of the final product is still assured by expensive 100% tests of the finished sub-assemblies. Due to the increasing costs for assembly and test of electronic products and the trends towards miniaturization and higher functionality, this kind of quality control must be replaced by integrated test strategies already in the assembly process and by quality assurance of components and materials. This problem is becoming more important due to the assembly of new and more highly integrated components such as bare dice or chip size packages. The processing of these components is in fact a combination of capable processes and intelligent in-line tools to assure the manufacturing quality. Furthermore, the assembled components themselves must fulfil a higher level of quality. Both misunderstanding and ignorance of these correlations can easily lead to complex failure mechanisms (i.e. solder beading, voiding, popcorning), that are very costly and difficult to handle. At the FAPS, a method has been pursued to shift quality assurance from the test panel into production and to prepare a basis for fast process controls. The target is to decrease testing costs and to lower the scrap rate by installing an in-process quality assurance system. In this paper, the principles of such an accompanying quality system are presented. The two basic assumptions, capable processes and intelligent tools for in-process inspection, are introduced and their realization in the Institute´s laboratory is presented