지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
이용수10
국 문 초 록 v영 문 초 록 vii목 차 ixList of Figures xiList of Tables xiii1. 서 론 12. 이론적 배경 32.1 솔더 접합부의 취성파괴 32.2 PCB 표면처리 52.3 금속간화합물 (Intermetallic compound) 72.3.1 Sn / Ni 시스템 72.3.2 Sn / Cu 시스템 82.3.3 Sn-3.0Ag-0.5Cu based 솔더와 무전해 Ni 계면반응 92.4 솔더 접합부 파괴 (Fracture) 102.4.1 Black pad 112.4.2 취성파괴에 영향을 주는 인자 122.4.2.1 전단 속도 (Shear Speed) 122.4.2.1 전단 높이 (Shear Height) 132.4.2.1 솔더 부피 (Solder Volume) 132.4.2.1 표면처리 (Surface Finish) 132.4.2.1 등온 시효 (Aging) 142.4.2.1 Ni-P 층 두께 (Thickness of Ni-P Layer) 142.4.2.1 P 함량 (Phosphorus Content) 143. 실험 방법 233.1 Test vehicle board 디자인 233.2 솔더 접합부 충격 특성 평가 243.2.1 고속전단시험 (High Speed Shear Test) 243.2.2 낙하충격시험 (Drop Test) 243.2.3 취성파괴율 평가 지표 244. 결과 및 고찰 334.1 전단강도 (Shear Strength) 평가 334.2 취성파괴 (Brittle Fracture) 평가 344.2.1 파괴모드 (Fracture Mode)분석 344.2.2 취성파괴율 (Brittle Fracture rate) 분석 374.3 낙하충격 신뢰성 분석 394.4 무전해 Ni/Sn 취성파괴 메커니즘 414.4.1 금속간 화합물 & 미세구조 414.4.2 NiSnP 금속간 화합물 및 Nano-void 영향 435. 결 론 476. 참고 문헌 48List of FiguresFig. 2-1. Phase diagram of Sn-Ni. 16Fig. 2-2. Phase diagram of Sn-Cu. 17Fig. 2-3. IMC formation process of ENIG/Sn. 18Fig. 2-4. Correlation of Fracture mode & shear strength. 20Fig. 2-5. Fracture mode of solder joint(ductile & brittle fracture). 21Fig. 2-6. Black pad. 22Fig. 3-1. Test vehicle board design. 26Fig. 3-2. Condition of reflow process. 27Fig. 3-3. Schematic of ball shear test. 28Fig. 3-4. Schematic view of a test vehicle for a drop test. 30Fig. 3-5. Schematic of drop tester. 31Fig. 3-6. Fracture mode determination by the percentage of the brittle fracture region on the fracture surface. 32Fig. 4-1. Comparison of shear strength(ENIG Vs ENEPIG). 33Fig. 4-2. Fracture comparision on ductile & brittle area. 34Fig. 4-3. EDS results on ductile & brittle area. 35Fig. 4-4. Fracture mod variation with strain rate of HSS test: (a)ENIG, (b)ENEPIG. 36Fig. 4-5. Comparision of brittle fracture rate. 38Fig. 4-6. Drop reliability results: (a)ENIG, (b)ENEPIG. 39Fig. 4-7. Cross-section SEM image of BGA package after drop test (x 10k). 40Fig. 4-8. Cross section point of Ni-Sn-P layer. 41Fig. 4-9. Microstructure comparision in the solder: (a)ENIG, (b)ENEPIG. 42Fig. 4-10. IMC thickness ans shape of solder joints: (a)ENIG, (b)ENEPIG. 42Fig. 4-11. The TEM results of the (Cu, Ni)6Sn5 IMC/ Ni(P) interfaces. Thickness of P-rich Ni layer and size of nano-void formed in NiSnP layer vary with the type of surface finishing: (a)ENIG, (b)ENEPIG. 44Fig. 4-12. The TEM micrographs of the (Cu, Ni)6Sn5 IMC/Ni(P) interfaces: (a)ENIG, (b)ENEPIG. 45Fig. 4-13. EDX results: (1)(Cu, Ni)6Sn5 (2)NiSnP, (3) P-rich Ni layer. 46List of TablesTable 2-1. Application of PCB surface finish. 15Table 2-2. Interfacial reation layers formed between Sn-3.0Ag-0.5Cu solder, and OSP Cu, Ni-P base metalsFormulations of epoxy adhesive samples. 19Table 3-1. Schematic view of BGA package for a drop test. 29Table 4-1. Comparison of vrittle fracture rate(rate data). 38
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