Flexible Encapsulant Materials For Micro-Fluid Ejection Heads And Methods Relating Thereto

Abstract

Thermally curable encapsulant compositions, micro-fluid ejection devices, and methods for protecting micro-fluid ejection heads. One such encapsulant composition may include one having from about 50.0 to about 95.0 percent by weight of at least one cross-linkable resin having a flexible backbone; from about 0.1 to about 20.0 percent by weight of at least one thermal curative agent; and from about 0.0 to about 50.0 percent by weight filler, and exhibits a relatively low shear modulus upon curing (e.g., less than about 10.0 MPa at 25° C.).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the disclosed embodiments may become apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale, wherein like reference numbers indicate like elements through the several views, and wherein:

FIG. 1 is a perspective view of a micro-fluid ejection device according to an exemplary embodiment of the disclosure;

FIG. 2 is a perspective view, not to scale, of an ink jet printer capable of controlling a micro-fluid ejection device according to the disclosure;

FIG. 3 is a cross-sectional view, not to scale, of a portion of a micro-fluid ejection device according to an embodiment of the disclosure;

FIGS. 4-5 are exploded perspective views, not to scale, of a micro-fluid ejection device according to an exemplary embodiment of the disclosure;

FIG. 6 is an exploded perspective view of a micro-fluid ejection head assembly and encapsulant material according to an embodiment of the disclosure;

FIG. 7 is a perspective view of the micro-fluid ejection head assembly of FIG. 6;

FIG. 8 an exploded perspective view of a micro-fluid ejection head assembly and encapsulant material according to another embodiment of the disclosure;

FIG. 9 is a cross-sectional view, not to scale, of a micro-fluid ejection device incorporating a prior art encapsulant material; and

FIG. 10 is a cross-sectional cutaway side view, not to scale, of a portion of a micro-fluid ejection device according to an embodiment of the disclosure.

Claims

1. A thermally curable encapsulant composition for a micro-fluid ejection head, the encapsulant composition comprising: from about 50.0 to about 95.0 percent by weight of at least one cross-linkable epoxy resin having a flexible backbone;from about 0.1 to about 20.0 percent by weight of at least one thermal curative agent; andfrom about 0.0 to about 50.0 percent by weight filler,

2. The encapsulant composition of claim 1 wherein the at least one thermal curative agent comprises a curative agent selected from the group consisting of imidazoles, amines, peroxides, organic accelerators, and sulfur.

3. The encapsulant composition of claim 1, further comprising from about 0.0 to about 10.0 percent by weight silane coupling agent.

4. The encapsulant composition of claim 1, wherein the filler comprises from about 0.0 to about 50.0 percent by weight fumed silica.

5. The encapsulant composition of claim 1, further comprising from about 0.0 to about 50.0 percent by weight phenolic cross-linking agent.

6. The encapsulant composition of claim 5, wherein the phenolic cross-linking agent is selected from the group consisting of bisphenol-F and bisphenol-M.

7. The encapsulant composition of claim 1, wherein the at least one thermal curative agent comprises an imidazole catalyst.

8. The encapsulant composition of claim 1, wherein the at least one thermal curative agent comprises an epoxy adduct of an aliphatic polyamine containing a primary amino group.

9. The encapsulant composition of claim 1, wherein the flexible backbone of the epoxy resin is selected from the group consisting of polyglycol, polybutadiene, and polysilsoxane structures.

10. A micro-fluid ejection head comprising a thermally curable encapsulant disposed adjacent to a fluid ejection surface thereof, the encapsulant having a shear modulus of less than about 10.0 MPa at 25° C.

11. The micro-fluid ejection head of claim 10, wherein the encapsulant comprises an encapsulant material having a shear modulus of less than about 5.0 MPa at 25° C.

12. A micro-fluid ejection head comprising a thermally curable encapsulant disposed adjacent to a fluid ejection surface thereof, the encapsulant having a glass transition temperature of less than about 90° C.

13. The micro-fluid ejection head of claim 12, wherein the encapsulant comprises and encapsulant material having a glass transition temperature of less than about 60° C.

14. A method for protecting a micro-fluid ejection head comprising applying a thermally curable encapsulant material adjacent to a fluid ejection surface of the ejection head, the encapsulant material comprising: from about 50.0 to about 95.0 percent by weight of at least one cross-linkable epoxy resin having a flexible backbone;from about 0.1 to about 2.0 percent by weight of at least one thermal curative agent; andfrom about 0.0 to about 5.0 percent by weight filler,wherein the composition exhibits a relatively low shear modulus upon curing,curing the adhesive composition to provide a micro-fluid ejection device.

15. The method of claim 14 wherein applying an encapsulant material comprises applying an encapsulant material comprising a mixture having a shear modulus of less than 10.0 MPa at 25° C.

16. The method of claim 14 wherein applying an encapsulant material comprises applying an encapsulant material comprising a mixture having a shear modulus of less than 3.0 MPa at 25° C.

17. The method of claim 14 wherein applying an encapsulant material comprises applying an encapsulant material comprising a mixture having a shear modulus of less than 1.0 MPa at 25° C.

18. The method of claim 14 wherein applying an encapsulant material comprises applying an encapsulant material comprising a mixture having a glass transition temperature of less than 65° C.

19. The method of claim 14 wherein applying an encapsulant material comprises applying an encapsulant material comprising a mixture having a glass transition temperature of less than 25° C.