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Quality Manufactory Page 1 Taguchi Method and SPC system in Semiconductor Manufacturing Chin-Yuan Chen Quality Manufactory Advance Semiconductor Engineering Manufacturing Company, Ltd Fisher_Chen@aseglobal.com April 30, 2010 Slide 2 Quality Manufactory Page 2 This presentation will cover the following topics, Taguchi Method Application in Assembly and Testing Site, SPC appliation system in Assembly process. Abstract: First, to present basic process introduction of semiconductor of assembly and testing. Taguchi Methodology and examples of assembly/test will be shown. To assist engineers to find root casue and enhance process capability, reduce variance, improve process capacity. Our company offer complete statistic training to new engineers. However, SPC methodology is most important tool for process control. To understand SPC concept, QC tools and OCAP(Out of Control Action Plan) become basic request of engineers. JMP software Slide 3 Quality Manufactory Page 3 The statistical software in ASE Slide 4 Quality Manufactory Page 4 The statistical software in ASE Slide 5 Quality Manufactory Page 5 1.Assembly/Test brief introduction 2. Taguchi Method in test site - Enhance wrinkle bump yield 3. Taguchi Method in Assembly site - Gold Wire Diameter Reduction Evaluation 4. SPC in Assembly site Content: Slide 6 Quality Manufactory Page 6 1. Assembly/Test brief introduction Slide 7 Quality Manufactory Page 7 What common point they had? What common point they had? Slide 8 Quality Manufactory Page 8 Slide 9 Quality Manufactory Page 9 Slide 10 Quality Manufactory Page 10 Slide 11 Quality Manufactory Page 11 Engineering Test Wafer Bumping/Probing Materials Assembly Final Test Module, Board Assembly & Test (DMS) Foundry Circuit Design ASE Vision:The Comprehensive Solution Slide 12 Quality Manufactory Page 12 Brief Assembly Process ( ) ............ Slide 13 Quality Manufactory Page 13 Brief Assembly Process ............ Slide 14 Quality Manufactory Page 14 Brief Assembly Process (20um) (40um) Slide 15 Quality Manufactory Page 15 Brief Assembly Process Slide 16 Quality Manufactory Page 16 Brief Test Process Slide 17 Quality Manufactory Page 17 Brief Test Process TESTER TEST HEAD Loadboard Contact pushor Contactblade Dutsocket Interface Handler Wafer Slide 18 Quality Manufactory Page 18 2. Taguchi Method in test site Slide 19 Quality Manufactory Page 19 Wrinkle bump issue Wrinkle bump Normal bump Bump Status Check Low Yield Slide 20 Quality Manufactory Page 20 Normal BumpWrinkle Bump Test Pin Slide 21 Quality Manufactory Page 21 If you are engineer, then what will you improve? Normal BumpWrinkle Bump Slide 22 Quality Manufactory Page 22 Good Contact Good Yield Hint Slide 23 Quality Manufactory Page 23 Contact deeper (Enhance Over Drive) Normal BumpWrinkle Bump Slide 24 Quality Manufactory Page 24 Taguchi Method Slide 25 Quality Manufactory Page 25 Taguchi Method - Analysis To choose L9 Taguchi experiment matrix and consider two response(y) as above table. Slide 26 Quality Manufactory Page 26 Taguchi Method- Analysis Slide 27 Quality Manufactory Page 27 3. Taguchi Method in Assembly site Slide 28 Quality Manufactory Page 28 1.Customer want cost saving with device, and to reduce gold wire diameter. 2.Current diameter is 25um, customer request to reduce as 20 um. 3.Current composition is Au, customer need to replace by Au-Pb. History Slide 29 Quality Manufactory Page 29 Structure 652 golden wire Slide 30 Quality Manufactory Page 30 Taguchi Matrix Slide 31 Quality Manufactory Page 31 Taguchi Analysis Result On Desirability Functions The desirability functions are smooth piecewise functions that are crafted to fit the control points. The minimize and maximize functions are three-part piecewise smooth functions that have exponential tails and a cubic middle. The target function is a piecewise function that is a scale multiple of a normal density on either side of the target (with different curves on each side), which is also piecewise smooth and fit to the control points. These choices give the functions good behavior as the desirability values switch between the maximize, target, and minimize values. For completeness, we implemented the upside-down target also. JMP doesn't use the Derringer and Suich functional forms. Since they are not smooth, they do not always work well with JMP's optimization algorithm. Slide 32 Quality Manufactory Page 32 4. SPC in Assembly site Slide 33 Quality Manufactory Page 33 Slide 34 Quality Manufactory Page 34 Slide 35 Quality Manufactory Page 35 Slide 36 Quality Manufactory Page 36 (Enhance wrinkle bump yield, Gold Wire Diameter Reduction Evaluation) Slide 37 Quality Manufactory Page 37 ( ) PBGA( ) PBGA