Investigation and Methods Using Various Release and Thermoplastic Bonding Materials to Reduce Die Shift and Wafer Warpage for eWLB Chip-First Processes
Investigation and Methods Using Various Release and Thermoplastic Bonding Materials to Reduce Die Shift and Wafer Warpage for eWLB Chip-First Processes
复制标题
使用各种脱模和热塑性粘合材料来减少 eWLB 芯片优先工艺的芯片移位和晶圆翘曲的研究和方法
DOI：
10.1109/ectc.2019.00063
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
M. Wohrmann
中科院分区：
文献类型：
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作者：
M. Fowler;John P. Massey;T. Braun;S. Voges;R. Gernhardt;M. Wohrmann
当今的扇出晶圆级封装（FOWLP）工艺使用由环氧树脂模塑化合物（EMC）组成的有机基板，该环氧树脂模塑化合物（EMC）使用热压工艺形成。EMC晶圆是一种经济高效的方法，可以实现更小尺寸的封装，而无需使用无机基板，从而生产更薄、更快的芯片封装，而无需插入层或硅通孔（TSV）。使用用于FOWLP的嵌入式裸片技术（eWLB）的一种方法是在中间载体晶片上的面朝下配置中的芯片优先（模具优先）裸片组合件。理想的芯片附着方案应最大限度地减少包覆成型（芯片移位）期间芯片的横向移动，并最大限度地减少导致芯片突出（支座）的键合材料的垂直变形。理想的管芯附接材料应提供对EMC晶片的足够粘附力而不引起过度的衬底翘曲，同时允许合适的剥离工艺，包括完全去除残留物。附着方案还必须经受住在载体释放之前执行的任何热、机械和化学过程。粘结材料还必须对EMC材料具有足够的粘附力，以克服这种应力而不发生粘结失效。防止由于载体衬底与EMC材料之间的热膨胀系数（CTE）失配而导致的横向管芯移位和变形可以使用适当的接合材料来实现。使用芯片的第一个芯片贴装过程中，本调查将解决芯片移位和变形使用各种释放和热塑性粘接材料。还包括使用不同EMC产品和具有不同热膨胀系数（CTE）的载体的组合。然后，成功的对将使用机械释放或激光烧蚀释放技术进行载体释放。
Today's fan-out wafer-level packaging (FOWLP) processes use organic substrates composed of epoxy mold compound (EMC) created using a thermal compression process. EMC wafers are a cost-effective way to achieve lower profile packages without using an inorganic substrate to produce chip packages that are thinner and faster without the need for interposers or through-silicon-vias (TSVs). One approach using embedded die technology (eWLB) for FOWLP is a chipfirst (mold-first) die assembly in a face-down configuration on an intermediate carrier wafer. The ideal chip attachment scheme should minimize lateral movement of the die during over-mold (die shift) and also minimize vertical deformation of the bonding material which results in die protrusion (stand-off). An ideal die attach material should provide adequate adhesion to the EMC wafers without inducing excessive substrate warp, while permitting a suitable debonding process, including complete residue removal. The attachment scheme must also survive any thermal, mechanical, and chemical processes that are performed prior to carrier release. The bonding materials must also have sufficient adhesion to the EMC material to overcome such stress without bond failure. Preventing lateral die shift and deformation due to the coefficient of thermal expansion (CTE) mismatch between the carrier substrate and EMC material can be accomplished using an appropriate bonding material. Using a chip-first die attach process, this investigation will address die shift and deformation using various release and thermoplastic bonding materials. Combinations using different EMC products and carriers with various coefficient of thermal expansion (CTE) are also included. Successful pairs will then undergo carrier release using either mechanical release or laser ablation release technology.