After the parts were cleaned and rinsed, cleaning effectiveness was determined visual. Each cleaner was compared to the others as well as to the beads cleaned from the previous trial. Table 1 lists the rankings from this trial and how they initially and finally compared to the previous trial.
Table 1 Cleaning Efficiency and Comparison
| CLEANER
|
RANKING
|
INITIAL COMPARISON
|
FINAL COMPARISON
|
| Inpro-Clean
|
2
|
temp³ w/o temp
|
temp£ w/o temp
|
| De-Ox
|
3
|
temp < w/o temp
|
temp£ w/o temp
|
| Daraclean
|
1
|
temp³ w/o temp
|
temp£ w/o temp
|
| ND-17
|
4
|
temp > w/o temp
|
temp£ w/o temp
|
Initially it appeared that De-Ox was the only cleaner negatively impacted by temperature increases. However, after a final examination of the beads, it was noted that all of the cleaners were less effective at the elevated temperatures. It was speculated that the results may have been due to inadequate rinsing instead. It was noted during rinsing of other cleaners that the pressure at which the rinse DI water was delivered had effects on rinsing quality. The greater the pressure the better the rinsing.
Even though the rinsing of the parts raised questions about the effectiveness of some cleaners, Daraclean was by far the most effective chemistry selected. This cleaner along with Inpro-Clean 3800, will be used in the next phase of testing using ultrasonics. (The Inpro-Clean will be used because of wide range of substrate compatibility.)