Pan Cheng-Tang, Wang Shao-Yu, Yen Chung-Kun, Ho Chien-Kai, Yen Jhan-Foug, Chen Shi-Wei, Fu Fan-Rui, Lin Yi-Tzu, Lin Cing-Hao, Kumar Ajay, Shiue Yow-Ling
Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
Institute of Medical Science and Technology, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
Polymers (Basel). 2019 May 30;11(6):940. doi: 10.3390/polym11060940.
The electronic package interconnects electronic signals from one area to another and package delamination is a serious problem in the configuration of materials. This study focused on decreasing the delamination of the low-profile fine pitch ball grid array (LFBGA) and plastic ball grid array (PBGA) packages in terms of polymer thermal issue, metal bonding and bonding mechanisms. PBGA and LFBGA are a very common type of packaging processes in the electronics industry. The present study dealt first with delamination of the LFBGA packaging, through characterization and determination of physical and chemical properties such as surface roughness, surface energy, and contact angle. The relationship between surface roughness and delamination was verified through various roughness bonding experiments. In addition, the surface energy was determined by measuring the contact angle after cleaning the metal surface of Cu, Ni and Cr with Ar + O gas, and, this gas plasma treatment was applied to enhance the adhesive properties. The compositions of the surface were analyzed through an X-ray photoelectron spectroscopy (XPS). Also, the delamination issue between the corner of the heat sink cap and the epoxy resin was observed for delamination of the LFBGA packaging. Further, this study analyzed the PBGA packaging process through the finite element analysis simulation software ANSYS. To improve the heat sink cap delamination issue of the PBGA, a new chamfer design of the corner seat was streamlined to decrease the stress value and delamination. Besides, the simulation results demonstrated that the stress value reduced after increasing the shoulder length. The results implicate that the stress value is inversely proportional to the shoulder width and the chamfer radius. This study demonstrated that the optimization in design was able reduce the delamination phenomena in configuration material.
电子封装将电子信号从一个区域互连到另一个区域，而封装分层是材料配置中的一个严重问题。本研究聚焦于从聚合物热问题、金属键合及键合机制方面减少薄型细间距球栅阵列（LFBGA）和塑料球栅阵列（PBGA）封装的分层现象。PBGA和LFBGA是电子行业中非常常见的封装工艺类型。本研究首先通过表征和测定诸如表面粗糙度、表面能和接触角等物理和化学性质来处理LFBGA封装的分层问题。通过各种粗糙度键合实验验证了表面粗糙度与分层之间的关系。此外，通过用Ar + O气体清洁Cu、Ni和Cr的金属表面后测量接触角来确定表面能，并且应用这种气体等离子体处理来增强粘附性能。通过X射线光电子能谱（XPS）分析表面的成分。另外，观察了LFBGA封装中散热片帽角与环氧树脂之间的分层问题。此外，本研究通过有限元分析模拟软件ANSYS分析了PBGA封装工艺。为改善PBGA的散热片帽分层问题，对角座进行了新的倒角设计以降低应力值和分层现象。此外，模拟结果表明增加肩部长度后应力值降低。结果表明应力值与肩部宽度和倒角半径成反比。本研究表明设计优化能够减少配置材料中的分层现象。
