Issue link: https://iconnect007.uberflip.com/i/239245
characteristics of epig deposits for fine-line applications continues Figure 2: Wire bonding conditions. 150°C. The oven (high-temp oven PHH-101/ ESPEC) was used for heat treatment. The cross section image of IMC after mounting the solder ball was observed by FE-SEM (Ultra55/Carl Zeiss) after polishing by cross section polisher (CP) (SM-09010 /JEOL). The intermetallic (IMC) layer was analyzed by EDS (AXS/ Bruker). WBR was evaluated by wire bonding (HB16/ TPT) and pull test (Dage 4000/Dage) as shown in Figure 2. The condition of heat treatment for WBR was done for 16 hours at 175°C. The element analysis for each film was measured by Auger electron spectroscopy (AES) (9500F/JEOL). The condition of AES was shown in Table 4. The plasma test after heat treatment was performed by plasma cleaner (PC-1100/SAMCO). The condition of the plasma treatment was shown in Table 5. Figure 3: Over-plating of EPIG and ENEPIG. Pattern Ability for EPIG Deposits Figure 3 shows the comparison of pattern ability between ENEPIG process and EPIG process when using the substrate with15 µm as the space of wiring lines. Although ENEPIG process had over-plating in the space of the wiring line, no over-plating was observed for the EPIG process. Solder Joint Reliability For EPIG process and ENEPIG process, SJR with the film as plated (As-plated) and with heat treatment after mounting the solder ball (300 hrs HT) were evaluated by HSS test as shown in Figure 4. In this figure, M705 was used as the solder ball. The influence of Pd thickness was not confirmed within 0.05–0.2 µm. When comparing the film of as-plated, the broken energies of ENEPIG film were better Table 4: AES Conditions. Table 3: HSS Test Conditions. Table 5: Plasma Conditions. January 2014 • The PCB Magazine 15