IPA can be only dissolved with small amounts in KOH. Most times a saturated
solution
will be produced by floating IPA on the top of KOH. However, a smaller
undercutting
we could not notice. We have determinated the etch rate for 27% KOH
saturaded
with IPA by 70°C for our simulation tool SIMODE (please see
http://gemac.c.ntg.de/mst_eng.htm).

With kind regards
D. Zielke
GEMAC mbH
Germany