Measurement and Decapsulation of IC Molding Resin Using YAG Laser for Failure Analysis
Nagayoshi Kasashima and Tsuneo Kurita
Ingenious Micro-Manufacturing System Group, Advanced Manufacturing Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba East, 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564, Japan
We are now developing a laser decapsulation technique of IC molding resin for failure analysis. Laser machining shortens decapsulation process time and reduces adverse environment effects compared to conventional etching methods. However, pure laser decapsulation cannot avoid the damage of IC chips. Therefore, it is necessary to leave molding resin on the chip surface. In this paper, the decapsulation experiment results using a YAG laser are described. In addition, to estimate residual molding thickness, the method of measuring laser light-reflection intensity is proposed. The relation between molding thickness and light-reflection intensity was examined by irradiating a low-output processing laser. And the results of measurement and decapsulation experiments using an experimental system are also described.
-  D Corum and R. Chowdhury, “Practical applications of backside silicon etching,” In: ISTFA 95, 21st Int. Symp. for Testing and Failure Analysis, Santa Clara, CA, pp. 263-268, 1995.
-  C. K. Oh, Z. M.Wu, and S. Redkar, “A new deprocessing technique by selective wet-etch of passivation and inter metal dielectric layers for submicron devices,” In: ISTFA 2001, 27th Int. Symp. for Testing and Failure Analysis, Santa Clara, CA, pp. 319-322, 2001.
-  H. Suzuki and N. Yoshida, “The Decapsulation of IC/LSI with Fuming Nitric Acid as Etchant (in Japanese),” The 24th Symp. on Reliability and Maintainability, pp. 399-404, 1994.
-  M. Kruger, J. Krinke, K. Ritter, B. Zierle, and M. Weber, “Laserassisted decapsulation of plastic-encapsulated devices,” Microelectronics Reliability, Vol.43, pp. 1827-1831, 2003.
-  P. Schwindenhammer, H. Murray, P. Descams, and P. Poirier, “Determination of temperature change inside IC packages during laser ablation of molding compound,” Microelectronics Reliability, Vol.48, pp. 1263-1267, 2008.
-  A. Aubert, L. Dantas de Morais, and J. P. Rebrasse, “Laser decapsulation of plastic packages for failure analysis: Process control and artefact investigations,” Microelectronics Reliability, Vol.48, pp. 1144-1148, 2008.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 International License.