Effect of Halogen Freeing on Fatigue Properties of Electronics Printed Plasitic Board Masashi NAKAMURA1, Hideto SUZUKI1, Tetsuo MATSUMOTO2 and Tomonari OHTSUKI2 1 Ibaraki University, 4-12-1, Nakanarusawa, Hitachi-City, Ibaraki, 316-8511 JAPAN 2 DDK Ltd., 14, Matsuyama, Mooka-city, Tochigi, 321-4393, JAPAN ABSTRACT Recently, it is important to develop new packaging technology that is gentle for environment and human body in electronic packaging fields. The printed circuit board of electronic equipment will be developed using materials for substrates without halide fire retarding material (that is halogen-free material) as dioxin does not arise. However, reliability assurance becomes an important problem for substrates using halogen-free fire retarding material, since there are fears that strength and heat-resistance are inferior to conventional circuit materials. In this study, fatigue reliability of halogen-free substrate noticed as an environmental harmony type printed circuit board material was evaluated. The difference of fracture mechanism between halogen-free material and halogen material in fatigue fracture was demonstratively examined from mesoscopic viewpoint. Fatigue life of halogen-free material was longer than that of halogen material, though mechanical property of halogen-free material was almost equal to it of halogen material. From fractography using by SEM, it was indicated that the difference of fatigue life in halogen-free material and halogen material was controlled by the difference of a size of characteristic destruction pattern named “Unit Fracture Area”. It was thought that difference of resinoid type between halogen-free material and halogen material appears in the difference in fatigue life, since matrix resin was a weakest link in fatigue fracture, on the other hand, strength of halogen material and halogen-free material was equal in static fracture, since the glass fiber was a strongest link. KEYWORDS Fatigue Reliability, Halogen-free- Electronics Substrate, Fractography, Reinforced Plastics INTRODUCTION Recently, the miniaturization is required in electronic equipment products. As the result, high-density packaging technologies such as buildup substrate have rapidly advanced. In the meantime, the environmental problem becomes serious, and they worry about the effect of pollution to environment and to human body. Therefore, it is important to develop the gentle packaging technology for environment, namely ecological design technology in electronic packaging fields. There have been a series of research of fatigue reliability assurance of recycling engineering plastic material by authors, as it is shown in Fig.1 and Table 1. As the result, it was shown that the control of mesoscopic factor could improve the reliability of recycling engineering plastic materials. At present, the use of halide fire retardant that is included in printed circuit board has been controlled. This is
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