Issue link: https://iconnect007.uberflip.com/i/1010078
36 SMT007 MAGAZINE I AUGUST 2018 Alcohol-based Fluxes with Rosin, RO-class (High Rosin) All of the fluxes in this category (Fluxes 10–13) passed J-STD-004B SIR testing. Localized cleanliness testing reports a dirty result for all fluxes in the comb-down configuration, and for Flux 11 in the comb-up configuration, to the Class 2/3 limit provided by the test. RMA Fluxes Both of the RMA fluxes tested (Fluxes 14 and 15) pass J-STD-004B SIR testing. Localized cleanliness testing reports a clean result for both fluxes under all conditions. Corrosivity Index The CI values were calculated for each local- ized cleanliness test performed using the Class 2/3 limit of 250 µA. The values were averaged for the four tests performed for each combi- nation of flux and comb configuration. The final log SIR values recorded at 168 h for each configuration of flux and comb configuration were averaged for each of the twelve combs tested. These values were plotted and are shown in Figure 3. Note that CI values below 2.08 for an individual test indicate a clean condition and log SIR values above 8.0 for an individual comb would pass J-STD-004B SIR testing. The values show a large grouping of data points in the upper left portion of the graph, with log SIR values above 9.5 and CI values below 2.08. These data points correlate well, since high SIR and low CI are the desired values. However, there are three data points that present relatively low log SIR values (lower than 9) along with low CI values (below 2.08). These values tend to be contradictory, where a preferred low CI is reported by fluxes with marginal or failing SIR performance. In addition, there are a number of data points with log SIR values above 9.0 that report CI values above 2.08. These SIR values are one or more orders of magnitude higher than the established minimum limits for SIR but show high, undesirable CI values. These values Table 5: Alcohol-based rosin-bearing flux test results summary, RO-class fluxes. Table 6: RMA flux test results summary. Comb Up Comb Down Comb Up Comb Down Comb Up Comb Down Flux 10 PASS PASS CLEAN CLEAN CLEAN DIRTY Flux 11 PASS PASS CLEAN CLEAN DIRTY DIRTY Flux 12 PASS PASS CLEAN CLEAN CLEAN DIRTY Flux 13 PASS PASS CLEAN CLEAN CLEAN DIRTY Localized Cleanliness Test Class 2/ 3 (250/ 120) J-STD-004B SIR Test Results Localized Cleanliness Test Class 1 (500/ 60) Comb Up Comb Down Comb Up Comb Down Comb Up Comb Down Flux 14 PASS PASS CLEAN CLEAN CLEAN CLEAN Flux 15 PASS PASS CLEAN CLEAN CLEAN CLEAN Localized Cleanliness Test Class 2/ 3 (250/ 120) J-STD-004B SIR Test Results Localized Cleanliness Test Class 1 (500/ 60)