Method for removing photoresist with solvent and ultrasonic agitation
AssigneeThe Boeing Company
InventorPatrisha A. Doscher
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Abstract
Liquid solvents having superior cleaning power include at least one polar compound having at least one strongly electronegative oxygen, such as ethylene diacetate, and at least one alicyclic carbonate, such as ethylene carbonate, with or without other additives. The solvents exhibit low toxicity; are nonflammable, pH neutral, essentially nonvolatile, and aprotic; and have other chemical and physical properties that reduce the risk of exposing the user unnecessarily to hazardous conditions. Solvents comprising ethylene carbonate, ethylene diacetate, and, optionally, triethanolamine and/or N-methyl-2-pyrrolidone are superior cleaners for a wide range of residues and are environmentally and physiologically safe.
Claims7
A method for removing photoresist comprising the step of contacting a part that is coated with photoresist with an effective amount of a solvent to remove the photoresist while ultrasonically agitating the solvent,
- wherein the solvent comprises:
- (a) 40-50 vol % of at least one aprotic, alicyclic carbonate, the carbonate including ethylene carbonate;
- and
- (b) an effective amount of at least one aprotic polar compound selected from the group consisting of alkyl diesters, alkyl diethers, alkyl compounds containing both ester and ether groups, and mixtures thereof, the solvent being effective at removing photoresist by immersion of the photoresist-coated part in an ultrasonically agitated bath;
- the polar compound including ethylene diacetate, ethylene dibutyrate, or mixtures thereof;
- and
- the solvent including N-methyl-2-pyrrolidone and triethanolamine.
Dependencies are inferred from the claim text.