High temperature storage reliability of palladium coated copper wire in different EFO current settings

Research Progress of Palladium-Plated Copper Bonding Wire in Microelectronic Packaging

“…The dark gray area in Figure 9 is the Pd coverage area. Cheng et al [38] studied the effect of different EFO discharge currents (50, 70, and 90 mA) on the distribution of Pd on FAB using 18 µm PdCu wire (99.99 wt. % purity of copper, 0.1 µm thickness of Pd layer).…”

“…Stephan et al [20] used a 15 µm PdCu wire to test under different EFO discharge currents (40, 60, and 80 mA), and then studied the distribution of Pd on the FAB surface by optical imaging of the FAB surface through the bright field imaging technique. From Figure 10, it can be seen that as the EFO discharge current increases, the Pd coverage on the FAB projection surface Cheng et al [38] studied the effect of different EFO discharge currents (50, 70, and 90 mA) on the distribution of Pd on FAB using 18 µm PdCu wire (99.99 wt. % purity of copper, 0.1 µm thickness of Pd layer).…”

“…In the Pressure Cook Test (PCT) and unbias Highly Accelerated Stress Test (uHAST), EX1 wire has a better performance in bonding strength, tensile strain, and life extension, and the life of EX1 in uHAST is longer than that in PCT, and the shear strength after uHAST is more stable. Cheng et al [16,38] observed the distribution of Pd on FAB by setting high, medium, and low EFO discharge currents, and then studied the effect of Pd distribution on bonding reliability. The results show that under low EFO discharge current, Pd was unevenly distributed in FAB (Figure In addition, the "apple bite mark" indicating partial Pd coating on FAB also appeared (Figure 27a-1).…”

“… Pd distribution seen at the FAB cross-section with EPMA. ( a – c ) show the results for the FABs at low, medium, and high EFO current settings, respectively [ 38 ]. Copyright, 2018, Elsevier.…”

“… External corrosion of bonded balls after 500 h of HTST at 200 °C, as observed using SEM. ( a – c ) correspond to the low, medium, and high EFO current settings, respectively [ 38 ]. Copyright, 2018, Elsevier.…”