Application Study Of Six Sigma In Electronic Package Capacitor Solder Bridging Failure

As increasing market for various types of consumer electronics,the demand for electronic packaging is growing very fast.To meet the needs,semiconductor company needs to develop a variety of more advanced electronic package products.With the silicon wafer polishing technology getting more mature,it is able to build times more than the number of chips compared to previous in electronic package.So that is possible to encapsulate more advanced chips to meet the needs of customers.Higher electronic package cost and higher reliability performance are required as well.Therefore,in order to increase the capacity and performance of electronic package,overcoming any customer returned failure has become the most important task in quality management.This thesis majorly introduces the electronic packaging assembly process and multiple chips package,including the function of capacitor and structure of the package.The problem occurred repeatedly and also happened in a very low failure rate,there is no clue to find out process abnormality by routine analysis methods.By physical failure analysis methods like: electrical analysis and cross-section analysis,SEM/EDX analysis and other analysis methods,it is able to confirm the problem happened during the IR reflow.Its high temperature condition leads to capacitor solder bridging between its two terminals.Because of very low failure rate,Six Sigma based analysis method is introduced to solve the problem.First of all,MSA(measuring system analysis)and material analysis methods are used to study the production process and packaging material parameters.According to the fishbone analysis;the solder volume is suspected to be the biggest factor.Through sampling comparison for solder sizes of different batches of package capacitor: solder heights of affecting batches are much higher than the normal batches.Simulating the stress and temperature condition indicates that the distribution of different solder shape will promote capacitance solder bridging.Full DOE analysis is conducted to compare the results from different solder conditions,it is conclude d that a large amount of solder capacitor is the root cause of the solder bridging failure.Improvement measures and control measures focus on reducing the amount of solder and improving the formed shape of the solder.Finally to the follow-up effectivity of corrective actions,OQRM(ongoing quality monitoring)test conditions are enhanced.It confirms that the improvement actions have very effectively eliminated the defect rate to zero dppm.Finally,the client shows no return with the capacitor bridge failure after all improvement actions implemented.