Aqueous developable photoimageable compositions for use in photo-patterning methods

1. A photo-imageable precursor composition comprising:

finely divided particles of inorganic material comprising:

(a) electrically functional powders selected from electrically conductive, resistive, and dielectric particles; and

(b) inorganic binder having a glass transition temperature in the range of from 325 to 600° C.;

dispersed in:

an organic medium comprising;

(c) an aqueous developable, non-photosensitive polymer which is a copolymner, interpolymer or mixture thereof, wherein each copolymer or interpolymer comprises (1) a nonacidic comonomer comprising a C 1-10 alkyl acrylate, C 1-10 alkyl methacrylate, styrenes, substituted styrenes or combinations thereof and (2) an acidic comonomer comprising ethylenically unsaturated carboxylic acid containing moiety; and

(d) a bi-functional UV-curable monomer having a first and second functional unit, wherein the first functional unit is a vinyl group and the second functional unit is capable of forming a chemical bond by reaction with the carboxylic acid containing moiety, and

(e) further comprising an epoxide monomer.

2. A photo-imageable composition comprising the precursor composition of claim 1 and a photo-initiation system.

3. The photo-imageable composition of claim 2 further comprising organic solvent and wherein the photo-imageable composition is in the form of a paste suitable for screen-printing.

4. A tape comprising the photo-imageable composition of claim 2 .

5. A method of photo-patterning comprising the steps of:

(a) depositing the composition of claim 2 onto a substrate;

(b) initiating the reaction of the developable nonphoto-imageable polymer and the bi-functional monomer to form a photosensitive polymer and photo-patternable composition;

(c) exposing the photo-patternable composition of (b) and substrate of (a) to actinic radiation to form an exposed part;

(d) developing the exposed part of (b) to form a developed part; and

(e) firing the developed part of (c) to substantially remove the organic medium and substantially sinter the inorganic material.

6. The precursor composition of claim 1 further comprising an acrylic or methacrylic photo-hardenable monomer.

7. The precursor composition of claim 1 further comprising a catalyst.

8. The precursor composition of claim 1 wherein the vinyl group of the bi-functional UV-curable monomer is selected from a methacrylate, acrylate group and mixtures thereof.

9. The precursor composition of claim 1 wherein said electrically functional powders are selected from (i) Au, Ag, Pd, Pt, or Cu, (ii) RuO 2 , (iii) ruthenium-based polynary oxides, and (v) mixtures thereof.

10. The method of claim 5 wherein following step (a) there is a drying step to remove organic solvent present in the composition.

11. The method of claim 5 wherein the initiation step (b) occurs simultaneously with step (c).

12. The method of claim 10 wherein the initiation step (b) occurs simultaneously with drying step.

13. A photo-imageable precursor composition comprising:

finely divided particles of inorganic material comprising:

(a) electrically functional powders selected from electrically conductive, resistive, and dielectric particles; and

(b) inorganic binder having a glass transition temperature in the range of from 325 to 600° C.;

dispersed in:

an organic medium comprising;

(a) an aqueous developable, non-photosensitive polymer which is a copolymer, interpolymer or mixture thereof, wherein each copolymer or interpolymer comprises (1) a nonacidic comonomer comprising a C 1-10 alkyl acrylate, C 1-10 alkyl methacrylate, styrenes, substituted styrenes or combinations thereof and (2) an acidic comonomer comprising ethylenically unsaturated carboxylic acid containing moiety; and

(b) a bi-functional UV-curable monomer having a first and second functional unit, wherein the first functional unit is a vinyl group and the second functional unit is capable of forming a chemical bond by reaction with the carboxylic acid containing moiety and wherein the second functional unit of the bi-functional UV-curable monomer is selected from an epoxide, amine and mixtures thereof.

14. The precursor composition of claim 13 further comprising an acrylic or methacrylic photo-hardenable monomer.

15. The precursor composition of claim 13 further comprising a catalyst.

16. The precursor composition of claim 13 wherein the vinyl group of the bi-functional UV-curable monomer is selected from a methacrylate, acrylate group and mixtures thereof.

17. The precursor composition of claim 13 wherein said electrically functional powders are selected from (i) Au, Ag, Pd, Pt, or Cu, (ii) RuO 2 , (iii) ruthenium-based polynary oxides, and (v) mixtures thereof.

18. A photo-imageable composition comprising the precursor composition of claim 13 and a photo-initiation system.

19. The photo-imageable composition of claim 18 further comprising organic solvent and wherein the photo-imageable composition is in the form of a paste suitable for screen-printing.