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RISS 인기검색어
- 검색키워드
- 학과정보 : 金屬工學科 物理治金學專攻 (검색결과 2 건)
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Toughness and wear resistance of Cr cast iron have been studied at room temperature. Toughness has been investigated by bending test. And Wear resistance teat has been done by high speed wear machine. The results are as follow; 1. Ms, and Mf temperatures of 12%Cr cast iron ate in the range of 100∼205℃ 2. From the result of bending test, it results in lower toughness of 12%Cr cast iron than that of 17% due to lower Cr content. 3. Wear resistance of 12%Cr cast iron is superior to that of 17%Cr cast iron, because it is thought that hardness of 12%Cr cast iron is higher than that of 17%Cr iron to the 4∼5 extent. 4. To improve the wear resistance of cast iron, it is important to control the amout and distribution of K₂carbide in the martrix.
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Taguchi 통계적 실험 방법을 통한 semiconductor micro packaging用 raw material의 계면확산 방지
HTS is an Jedec reliability method of detecting heat crack or other fails when semiconductor stores high temperature. Temperature condition of experiment is 120, 150, 180℃, annealing time condition is 0hr, 100hr, 200hr in oven. HTS samples which was encapsulated EMC is decapsulated by nitric acid and samples exposure inner wire and chip pad. Because decapsulation used nitric acid is dangerous, Experiment must be progress laboratory prepared air venturation and safety outfites. Wire and chip pad decapsulated shear strength measures cutting force with hook tweezer tester when wire cut. Because of intermetallic compound brittleness which was wire open, wire shear strength result displays critical weak point with temperature and annealing time. After micro package cut cross section using by grinding and polishing machine, wire and chip pad boundary component be analyzed by SEM and EDX machine. This pupose is that boundary condition confirms correctly. All DOE(Disign of Experiment) was fundamental to taguchi statistics theory. When EMC keep high temperature, chemical gases appear various shapes because EMC was combined by many chemical components. This experiment analyzes EMC main chemical factor of HTS conditions, and confirms the alternation of intermetallic compound and EMC resin. The last conclusion is that diffusion mechanism examine and prevent intermetallic compound. Intermetallic compound and void happens Al-Au boundary at high temperature. Wire ball strength makes weak to intermetallic compound and void, and pad open will occur. Intermetallic compound and void will accelates diffusion rate by Br gas emitted from EMC at high temperature. When 2N gold wire involved 1wt% of Pd contacts Al pad, intermetallic compound and void will be prevent by small grain size and more fast reation of Pd-Al than Al-Au.
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