Chuang Wan-Chun, Huang Yi, Chen Po-En
Department of Mechanical and Electromechanical Engineering, Engineering Technology Research & Promotion Center, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
Materials (Basel). 2023 Apr 30;16(9):3482. doi: 10.3390/ma16093482.
This study investigated the impact of material properties of epoxy molding compounds on wafer warpage in fan-out wafer-level packaging. As there is currently a lack of comprehensive discussion on the various material property parameters of EMC materials, it is essential to identify the critical influencing factors and quantify the effects of each parameter on wafer warpage. The material properties include Young's modulus of the epoxy molding compound before and after the glass transition temperature (Tg) range of 25-35 °C (E) and 235-260 °C (E), coefficient of thermal expansion (α1, α2), and the temperature change (∆T) between E and E. Results show that, within the range of extreme values of material properties, E and α1 are the critical factors that affect wafer warpage during the decarrier process in fan-out packaging. α1 has a more significant impact on wafer warpage compared with E. E, α2, Tg, and ∆T have little influence on wafer warpage. Additionally, the study identified the optimized material property of the epoxy molding compound that can reduce the maximum wafer warpage in the X and Y directions from initial values of 7.34 mm and 7.189 mm to 0.545 mm and 0.45 mm, respectively, resulting in a reduction of wafer warpage of 92.58% (X direction) and 93.74% (Y direction). Thus, this study proposes an approach for evaluating the impact of material properties of epoxy molding compounds on wafer warpage in fan-out wafer-level packaging. The approach aims to address the issue of excessive wafer warpage due to material variation and to provide criteria for selecting appropriate epoxy molding compounds to enhance process yield in packaging production lines.
本研究调查了环氧模塑料的材料特性对扇出型晶圆级封装中晶圆翘曲的影响。由于目前缺乏对环氧模塑料各种材料特性参数的全面讨论，因此确定关键影响因素并量化每个参数对晶圆翘曲的影响至关重要。材料特性包括玻璃化转变温度（Tg）范围为25 - 35°C（E）和235 - 260°C（E）前后环氧模塑料的杨氏模量、热膨胀系数（α1、α2）以及E和E之间的温度变化（∆T）。结果表明，在材料特性的极值范围内，E和α1是影响扇出型封装去载过程中晶圆翘曲的关键因素。与E相比，α1对晶圆翘曲的影响更大。E、α2、Tg和∆T对晶圆翘曲影响较小。此外，该研究确定了环氧模塑料的优化材料特性，可将晶圆在X和Y方向上的最大翘曲量分别从初始值7.34 mm和7.189 mm降低至0.545 mm和0.45 mm，使晶圆翘曲分别减少92.58%（X方向）和93.74%（Y方向）。因此，本研究提出了一种评估环氧模塑料材料特性对扇出型晶圆级封装中晶圆翘曲影响的方法。该方法旨在解决因材料变化导致的晶圆过度翘曲问题，并为选择合适的环氧模塑料提供标准，以提高封装生产线的工艺良率。
