Photoimageable nozzle members and methods relating thereto
View Patent ↗Nozzle members, such as for a micro-fluid ejection head, micro-fluid ejection heads, and a method for making the same. One such nozzle member includes a negative photoresist composition derived from a first di-functional epoxy compound, a relatively high molecular weight polyhydroxy ether, a photoacid generator devoid of aryl sulfonium salts, an adhesion enhancer, and an aliphatic ketone solvent. The nozzle member has a thickness ranging from about 10 microns to about 30 microns.
1. A method for making an improved micro-fluid ejection head, the method comprising:
applying a first negative photoresist layer adjacent a device surface of a substrate, wherein the first negative photoresist layer is derived from a composition comprising a multi-functional epoxy compound, a first di-functional epoxy compound, a photoacid generator devoid of aryl sulfonium salts, an adhesion enhancer, and an aryl ketone solvent;
imaging a plurality of flow features in the first photoresist layer;
developing the imaged first photoresist layer to provide the plurality of flow features therein and a substantially planar thick film layer surface;
applying a second negative photoresist layer adjacent the thick film layer, the second negative photoresist layer being derived from a second photoresist formulation comprising a second di-functional epoxy compound, a polyhydroxy ether devoid of epoxy group, the photoacid generator devoid of aryl sulfonium salts, the adhesion enhancer, and an aliphatic ketone solvent;
imaging a plurality of nozzles in the second photoresist layer; and
developing the imaged second photoresist layer to provide a photoresist nozzle member adjacent the thick film layer.
2. The method of claim 1 , wherein the photo acid generator comprises a diaryliodonium hexafluoroantimonate.
3. The method of claim 1 , wherein the second di-functional epoxy compound comprises layer includes substantially equal parts of the first di-functional epoxy compound and a third di-functional epoxy compound having a weight average molecular weight less than a weight average molecular weight of the first di-functional epoxy compound.
4. The method of claim 1 , wherein the second photoresist layer is applied to the thick film layer by laminating the second photoresist layer to the thick film layer as a dry film laminate.
5. The method of claim 1 , wherein the aliphatic ketone solvent comprises cyclohexanone and, optionally, acetone.
6. The method of claim 1 , wherein the adhesion enhancer comprises an alkoxysilane compound.
7. The method of claim 6 , wherein the alkoxysilane compound comprises gamma-glycidoxypropyltrimethoxysilane.