Improving the Plastic Ball Grid Array Assembly Yield: A Case Study

Plastic Ball Grid Arrays電漿清洗製程良率改善之研究

10.29977/JCIIE.200607.0005

洪永祥(Y. H. Hung)；黃美玲( M. L. Huang)

PGBA組裝 ； 電漿清洗 ； 類神經網路 ； 基因演算法 ； PBGA assembly ； Plasma cleaning ； neural network ； genetic algorithm

工業工程學刊

23卷4期（2006 / 07 / 01）

311 - 318

英文

在半導體封裝PBGA製程中，電漿清洗是必要製程。主要負責封裝過程中所產生的污染源。特別在wire bonding及modling製程之前，若存在任何微小的有機污染物質，會使後製程組裝的不良率大幅提高。依據工廠數據顯示高階PBGA的重工成本高達3美金。因此之故，如何提升PBGA的製程良率降低生產成本，對封裝廠商而言是非常重要的品質課題。本研究，主要結合田口實驗方法及BPNN(back-propagation neural networks)神經網路與基因演算法(genetic algorithms)找尋最佳化的電漿清洗製程參數，藉以提升PGBA 的電漿清洗(plasma cleaning processes)製程品質與良率。

The plasma cleaning process cleaning the residual containments in the assembly processes is one of the major processes in the plastic ball grid arrays (PBGA) assembly processes. Especially, when there is any micron particle existed before wire bonding and molding, parts of nonconforming will increase. With the rapid growth in production, yield improvement to reduce the production cost is essential for PBGA industry. In fact, the plasma cleaning process before wire bonding and molding both enhances the PBGA yield and reduces the production cost effectively. This study combines neural network with Taguchi method to structure a well-trained prediction model, further searches for the optimal plasma cleaning parameter design through genetic algorithm, and finally enhances the process yield and production quality in a central Taiwan PBGA company.

1. Baranyi, A. D.,L. Seto,S. K. Chang(1998).Plasma cleaning to improve wire bonds.Electronic Packaging and Production,12-16.
2. Fairfield, C..Optimization of Ion and Electron Properties in IC Packaging Applications
3. Freeman, J.,D. Skapura(1991).Neural Networks
4. Ganesan G. S.,G. Lewis,H. M. Berg(1994).Characterizing organic contamination in IC package assembly.International Journal of Microcircuits Electronics Packaging,17(2),152-160.
5. Goldberg, D. E.(1989).Genetic algorithms in search, optimization, and machine learning
6. Harman, G. G.(1991).Reliability and Yield Problems of Wire Bonding in Microelectronics
7. Holland, J.(1975).Adaptation in natural and artificial systems
8. Kim, B.,D. W. Kim,G. T. Park(2005).Prediction of plasma-induced DC bias using polynomial neural network.Vacuum,79,111-118.
9. Kim, B.,S. Park(2003).Plasma diagnosis by recognizing in suit data using a modular backpropagation network.Chemometrics and Intelligent Laboratory Systems,65,231-240.
10. Kim, B.,S. Park(2001).An optimal neural network plasma molde: a casy study.Chemometrics and Intelligent Laboratory Systems,56,30-50.
11. Kim, S.(1991).The role of plastic adhesion in IC performance.Proceedings of the 41st Electronics and Computer Technology Conference,750-758.
12. Lee, C. F.,K. S. Pan(2003).Research in the Strength Improvement of Golden Wire Bonding in BGA by the Plasma Cleaning
13. Lee, C.,R. Gopalakrishnan,K. Nyunt,A. Wong, R. E.,Tan,,J. W. Ong(1999).Plasma cleaning of plastic ball grid array package.Microelectronic and Reliability,39,97-105.
14. Moser, E. M.,Ch. Faller,S. Pietrzko,F. Eggimann(1999).Modeling the function performance of plasma polymerized thin films.Thin Solid Films,355-356,49-54.
15. O''Kane D. F.,K.L. Mittal.(1974).Plasma cleaning metal surfaces.Journal of Vacuum Science and Technology,11(3),567-569.
16. Phadke, M. S.(1989).Quality Engineering Using Robust Design
17. Schrader, M. E.(1979).Surface contamination detection through wettability measurements. In: Surface Contamination: Its Genesis.Detection and Control,2,697-712.
18. Strobel, M.,C. S. Lyons,K. L. Mittal.Plasma Surface Modification of Polymers: Relevance to Adhesion.Adhesion Science and Technology
19. Su, C. T.,T. L. Chiang(2003).Optimizing the IC wire bonding process using a neural networks/genetic algorithms approach.Journal of Intelligent Manufacturing,14,229-238.
20. Tong, L. I.,C. T. Su,C. H. Wang(1997).The optimization of multi-response problems in Taguchi method.International Journal Quality Reliability Management,14,367-380.
21. White, M. L.(1970).The detection and control of organic contamination on surfaces
22. Wong, C. P.,R. McBride(1994).Pre-encapsulation cleaning methods and control for microelectronics packaging.Proceedings of the 44th Electronics and Computer Technology Conference,121-133.
23. Yang, Steve, L.,J. B. Bernstein,K. C. Leong(2002).Effect of The Plasma Cleaning Process on Plastic Ball Grid Array Package Assembly Reliability.IEEE Transactions on Ecectronics Packaging Manufacturing,25(2),91-99.
24. Yoshida, O.,N. Okabe,S. Nagayama,R. Yamagischi,G. Murakami(1989).Improvement of moisture resistance in plastic encapsulants MOS-IC by surface finishing copper leadframe.Proceedings of the 39th Electronics and Computers Conference,464-471.