近年來，隨著消費者對電子產品於便利、輕量及高效率之要求越來越高，三維封裝技術之研發漸趨重要，而按此發展趨勢，矽晶片之厚度將受一定範圍之限制，必要時需經過研磨、拋光等製程將之變薄。但當矽晶片厚度變薄時，可能導致電子產品於製造過程中產生矽晶片破壞之現象。故為了電子產品之可靠度以及良好之設計，矽晶片之應力強度測量是需要受到重視的。
矽晶片之強度可經由不同實驗方法進行量測，包含三點彎折（Three-Point Bending, 3PB）、四點彎折（Four-Point Bending, 4PB）與球型壓痕實驗（Ball-Breaker Test）等。但其中三點彎折與四點彎折實驗之載具架設對實驗結果具有明顯之影響性，例如載具與試片間之水平度等，除此之外，其矽晶片之準備也需相當注意，因為試片之邊緣缺陷（Edge Chipping）對實驗結果也具有一定程度之影響。而為了以較便利之方法求得矽晶片之應力強度，本研究選用球型壓痕實驗並搭配音射系統（Acoustic Emission, AE）進行測量矽晶片於初始破壞產生時所承受之接觸力量值，並且觀察矽晶片在承受不同接觸力量時之破壞情形。另一方面，本研究也將以商業之有限單元分析軟體ANSYS/LS-DYNA3DR進行球型探針、矽晶片與基板間接觸行為之數值模擬分析，並以赫茲接觸理論驗證該有限單元模型之正確性，接而將實驗結果與模擬結果兩方面比對以得到矽晶片之應力強度。
本研究利用上述之研究方法針對不同厚度及晶格排列之矽晶片進行應力強度之量測。另外，本研究也針對實驗之影響因子進行探討，其結果顯示矽晶片之表面積大小與邊緣缺陷對矽晶片應力強度之量測結果並無明顯影響性。然而矽晶片之表面粗糙度對實驗結果則有一定程度之影響，當表面粗糙度越大時，由於該粗糙部分與球型探針接觸時會造成應力集中現象而容易產生破壞情形，故所得之矽晶片應力強度較低。除此之外，本研究以各厚度之矽晶片應力強度為基準，藉由模擬方式探討基板材料對實驗結果之影響性，發現當矽晶片放置於較軟之基板上時，由於其緩衝力量之效果較佳，故可承受較高之接觸力量。然而對於厚度較薄之矽晶片而言，將之放置於越軟之基板時，由於彎曲行為對矽晶片之應力分佈影響將更為顯著，因此所能承受之力量反而較低。但總體而言，基板材料對實驗結果之影響將隨矽晶片之厚度增厚而變小。

3D or stacked-die packages are becoming increasingly popular in the electronic packaging industry because of the current market demand for cheaper and smaller products with high performance characteristics. As the result, the IC silicon wafers should be thinned through wafer-thinning processes to achieve greater packaging density, such as etching, grinding and polishing. However, it is possible to induce crack of the chips during manufacturing process. Therefore, this study aims to determine the strength of silicon die which can provide a design guideline to prevent the silicon die failure problem.
Several methods have already been adopted to determine the strength of silicon die. These methods include three-point bending test (3PB), four-point bending test (4PB) and ball-breaker test. However, 3PB and 4PB have difficulty for application not only in experiment set ups and silicon dies preparation but also in actual use because both edge and surface defects will influence the stability of strength evaluation. Therefore, the ball-breaker test is then proposed with the acoustic emission system (AE system) in this study to measure the allowable force of silicon die as the initial crack occurs. Besides, the failure modes of silicon die under different contact forces are also discussed in the study. Meanwhile, comparing with experiment data, the finite element method (FEM) analysis using commercial software ANSYS/LS-DYNA3DR are introduced to determine the silicon die strength. Moreover, the 3D model of the ball-breaker test is verified through the Hertzian contact theory.
The strength of silicon die with different thickness and crystal orientation are determined through the methodology of this study. Moreover, the factors that influence the experiment results through ball-breaker test are also investigated. The results show that the area and the edge defect of silicon die have no effect on the strength determination. However, the roughness of silicon die influences the results. As the roughness increases, the die strength decreases because stress concentration at the rough part on the surface will cause the die failure. Furthermore, based on the strength of silicon die with different thickness in this research, the simulation results show that the allowable force of silicon dies increases as the softer foundation material is applied due to the softer foundation has better capacity for absorbing the contact force. However, the failure of the thinner test die placed on the softer foundation is much easier to happen. This is because the tensile stress on the bottom surface of thinner die resulting from the bending behavior increases rapidly and significantly influences the die breakage. Overall, the influence of the foundation material decreases as the silicon die thickness increases.

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