플립칩의 미세화에 따른 열 특성 연구 = Study on the thermal perfermance of fine flip-chip package

다국어 초록 (Multilingual Abstract)

According to the trends of electronic package to be smaller, thinner and more integrative, Flip Chip Ball Grid Array (FCBGA) become more used for mobile phone. However, the flip chip necessarily generate the heat by the electrical resistance and generated heat is increased due to reduced distribution area of the heat in accordance with the miniaturization trend of the package. Thermal issues can result in problems of devices that are sensitive to temperature and stress. Then the heat can generate problemsto the system. In this paper, in order to improve the thermal issues of FCBGA, thermal characteristics of FCBGA was analyzed qualitatively by
using the general heat transfer module of Comsol 4.2a and Recently, by the trends of electronic package to be smaller, thinner and more integrative, fine bump is required. but It can result in the electrical short by reduced cross-section of UBM and diameter of bump. Especially, the formation of IMCs and KV can have a significant affects about electrical and mechanical properties. In this paper, we analyzed the thermal deformation of flip-chip bump by using FEM. Through Thermal Cycling Test (TCT) of flip-chip package, We analyzed the properties of the thermal deformation. and We confirmed that the thermal deformation of the bump can have a significant impact on the driving system. So we selected IMCs thickness and bump diameter as variable which is expected to have implications for characteristics of thermal deformation. and we performed analysis of temperature, thermal stress and thermal deformation. Then we investigated the cause of the IMC's effects. and In order to solve thermal issues, flip chip with thermal design is proposed by the simulation. and the improvement of heat dissipation characteristics about 48% was confirmed.

목차 (Table of Contents)

• 1. 서 론 1
• 1.1 연구배경 1
• 1.2 연구동향 3
• 1.3 연구목적 9
• 2. 플립칩 패키지의 열 특성 분석 11
• 2.1 플립칩 패키지의 열해석 모델링 11
• 2.2 플립칩 패키지의 발열 특성 및 열변형 특성 18
• 3. IMC층의 영향에 따른 플립칩 범프의 열변형 해석 32
• 3.1 IMC층의 유무에 따른 열변형 해석 32
• 3.2 IMC층의 두께와 범프의 직경에 따른 열변형 해석 45
• 3.3 범프의 열변형에 미치는 Void의 영향 54
• 3.4 IMC층의 종류에 따른 범프의 열변형 해석 57
• 4. 플립칩 패키지의 열소산 구조 최적화 62
• 4.1 마이크로 패턴을 이용한 열구조 설계 및 해석 62
• 4.2 Semi-Embedded를 이용한 열구조 설계 및 해석 74
• 4.3 플립칩 패키지의 최적 열소산 구조 설계 78
• 5. 결 론 82
• 참고문헌 83
• Abstract 88