Issue link: https://iconnect007.uberflip.com/i/1527952
OCTOBER 2024 I PCB007 MAGAZINE 31 nickel plating stacks. e demand for thin, low-porosity palladium deposits that produce an effective copper diffusion layer will be crit- ically important. Table 2 shows the reliabil- ity performance of EPIG aer stressing for 300 hours at 150°C. Figure 7 shows the wire bonding reliability at different palladium and gold thicknesses. Higher gold thicknesses, for example, allow for thinner palladium depos- ple soldering operations, as evidenced in the wetting balance graphs in Figure 6. DIG has important advantages as a high frequency final finish for less complex assembly processes. It is a good substitute for immersion silver and has demonstrated compatibility with wire bond- ing. DIG does not appear to be fully compat- ible with solderless assembly or contact resis- tance connector applications. Are there alternative PCB plating technolo- gies Uyemura is developing? With respect to final finish alternative pro- cesses, we have several products in our com- mercial portfolio. Most notable are EPIG, EPAG, and IGEPIG, two premium final fin- ish nickel-free electrolytes. ese processes are comprised of electroless palladium and immersion/RAIG gold. e drivers for the nickel-free systems are twofold. e removal of nickel from the stack reduces signal insertion loss and improves the performance of high-speed circuits. High fre- quency designs are moving well above the 100 GHz speed and preclude the use of magnetic metal deposits. e second driver is finer densities on trace spacing, which are incompatible with thick Figure 6: DIG wetting balance results after reflow simulation. No anti-tarnish used. Table 2: Solder joint formed with SAC305 solder