On Clustering of Defects and Yield of Smt Assemblies

SMT assembly yield modeling is an important part of Design for Manufacturing (DFM) and of Design for Test (DFT) of electronic products. If the yield can be estimated accurately, the manufacturing cost, the capacity of the manufacturing line, the procurement of material, and the on–time–delivery of the product can be properly managed . On the other hand, if yield predictions are inaccurate, the effects will be felt in the manufacturing process and also in the profit margin of the product. An accurate yield model is particularly needed when the product is in the design stage and trade–offs in DFM and testability can still be made.