Abstract:
With increasing miniaturization and complex features of modern electronic products, there is a growing demand for highly integrated printed circuit boards. Small passive ...Show MoreMetadata
Abstract:
With increasing miniaturization and complex features of modern electronic products, there is a growing demand for highly integrated printed circuit boards. Small passive parts such as the component size 01005 (0402 metric) provide smaller assemblies for mobile consumer products, sensor devices as well as medical applications. Based on literature, the solder paste printing process is considered to be the most critical process step in the Surface Mount Technology. Solder Paste Inspection (SPI) offers opportunities for monitoring this process step. Furthermore closed loop applications using SPI data are highly offered in the industry, e.g. for the correction of a measured print offset or the specific execution of an internal understencil cleaning process of the printer. The introduction of micro passive parts does however have its drawbacks especially in an assembly with heterogeneous components. On the process side, the paste printing with a wide spectrum of components often induces critical values for the aspect ratio on the stencils used. Furthermore, the micro passive parts place high demands on the inspection processes by SPI and Automatic Optical Inspection (AOI) and Automatic X-ray Inspection (AXI). Beside the machine capability for high quality inspection the correlation of all inspection data and the cause of defects is still not fully understood and offers enormous potential. This study is a holistic approach for evaluation of inspection data of the process steps for acquisition of knowledge about the development and avoidance of real defects. For the investigations, a 4-layer-PCB (FR4) is developed with dimensions of 180 mm by 110 mm in size and a thickness of 1.0 mm. Over 20 different kinds of packages (e.g. BGA, QFN, SOT, etc.) and passives of the component size 0603 and 01005 provide a mixed assembly with about 1,250 components on each PCB. Design of experiments is used for the study for statistical analyses of a wide range of influencing factors. In the ...
Date of Conference: 25-28 January 2016
Date Added to IEEE Xplore: 10 March 2016
ISBN Information: