Title :
Under bump metallurgies for a wafer level CSP with eutectic Pb-Sn solder ball
Author :
Cho, Soon-Jin ; Kim, Ji-Yon ; Park, Myung-Geun ; Park, Ik-Sung ; Chun, Heung-Sup
Author_Institution :
Module/Package Team, Hyundai Electron. Ind., Japan
Abstract :
Six types of under bump metallurgies (UBM) were investigated in terms of ball shear strength, fracture surface analysis, the adhesion of sputter-deposited metal to dielectric polymer, and microstructure observation to optimize the UBM of a wafer level chip size package (WLCSP) with Pb-Sn eutectic solder ball. UBMs investigated in this paper include Ti(0.2 μm)/Cu(1.0 μm), Ti(0.2 μm)/Cu(5.0 μm), Ti(0.2 μm)/Ni(0.2 μm)/Cu(1.0 μm), Al(0.2 μm)/Ni(0.2 μm)/Cu(1.0 μm), Ti(0.2 μm)/Ni(1.0 μm), Ni(0.2 μm)/Cu(1.0 μm). The purpose of this research is to investigate the effect of reflow cycle and two reliability stress, i.e., temperature cycling and pressure cooker soaking, on the ball shear strength as well as interface microstructure evolution of UBMs
Keywords :
adhesion; chip scale packaging; eutectic alloys; fracture; lead alloys; shear strength; soldering; tin alloys; Al-Ni-Cu; Ni-Cu; Pb-Sn; Ti-Cu; Ti-Ni; Ti-Ni-Cu; adhesion; eutectic Pb-Sn solder ball; fracture surface analysis; interface microstructure; pressure cooker soaking; reflow cycle; reliability stress; shear strength; temperature cycling; under bump metallurgy; wafer level chip size package; Costs; Dielectrics; Electronics industry; Packaging; Polymers; Random access memory; Temperature; Testing; Tin; Wafer scale integration;
Conference_Titel :
Electronic Components & Technology Conference, 2000. 2000 Proceedings. 50th
Conference_Location :
Las Vegas, NV
Print_ISBN :
0-7803-5908-9
DOI :
10.1109/ECTC.2000.853260
