PMA - Propylene Glycol Monomethyl Ether Acetate — Frequently Asked Questions

It dissolves the novolac and chemically amplified resins used in photoresists, wets silicon wafers uniformly so the spin-coated film is even, and evaporates cleanly without leaving residue. Its favourable toxicological profile compared with the ethylene-series acetates also matters in a cleanroom. It is used both as the resist carrier and as an edge-bead removal and cleaning solvent.

By orders of magnitude in purity specification. Electronics grade controls metal ions at parts per billion and specifies particle counts, because a single metal ion or particle in the wrong place will ruin a wafer worth far more than the solvent. Coatings grade has no such requirements. The two are not interchangeable and the grade must be stated at enquiry.

Yes, and that is one of its main coatings applications. Because the hydroxyl is esterified there is no active hydrogen to react with isocyanate, so the solvent is inert to the crosslinking chemistry. Its moderate evaporation rate suits both spray and baking finishes, making it a general-purpose choice in that system.

Yes. PGMEA is the common technical abbreviation, particularly in electronics, and both refer to propylene glycol monomethyl ether acetate, CAS 108-65-6. The CAS number together with the grade specification is the reliable way to order, since trade and technical names vary.