This month we seem to have more patent activity than usual in the area of quats with epoxides used in the semiconductor industry.
This publication, Matsuura, Y.; Sato, A.; Yamazawa, T. (Namics Corporation) US Patent Application Publication No 2024/0132714, 25-Apr-2024, describes the use of a variety of quat salts in a system that I will attempt to explain according to my novice understanding that may be incorrect.
If I understand correctly (which might not be the case), the goal of this technology is to ensure that the electrode “bump” of a semiconductor is accessible while protecting the rest of the semiconductor surface. For this purpose, a cured epoxy resin and a “filler” (like silica) is used to coat the semiconductor with the electrode protruding for connection to another component.
The epoxy resin is cured with a curing agent, typically containing an amine.
The patent claims that the presence of an ionic compound (chosen from a group with many quat salts) is crucial to ensure uniform distribution of the epoxy resin and filler but the patent does not explain why the ionic compound works. I speculate that the anion of the ionic compound serves as an initiator for the curing of the epoxy resin by the amine-based curing agent.
Regardless of whether this speculative explanation is correct, the ionic compounds that are explicitly claimed in Claim 8 contain quat cations familiar to us as PTC practitioners and they are:
• Methyltrioctylammonium tosylate
• Methyltrioctylammonium hexafluorophosphate
• Methyltrioctylammonium imidodisulfuryl fluoride
• Methyltrioctylammonium bis(trifluoromethanesulfonyl)imide
• Tributyldodecylphosphonium tosylate
• Tributyldodecylphosphonium dodecylbenzenesulfonate
• Tributylmethylammonium bis(trifluoromethanesulfonyl)imide
• Tetrabutylammonium hexafluorophosphate
• 1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide
• Tributyldodecylphosphonium bis(trifluoromethanesulfonyl)imide
• 1-Hexyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide
• Trimethylpropylammonium bis(trifluoromethanesulfonyl)imide
• 4-(2-Ethoxyethyl)-4-methylmorpholinium bis(trifluoromethanesulfonyl)imide
• 1-Butyl-3-dodecylimidazolium bis(trifluoromethanesulfonyl)imide
• N-Oleyl-N,N-di(2-hydroxyethyl)-N-methylammonium bis(trifluoromethanesulfonyl)imide
• Tributyl[3-(trimethoxysilyl)propyl]phosphonium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide
