Methods and Apparatuses for Applying a Protective Material to an Interconnect Associated with a Component

Abstract

Methods and apparatuses for applying a protective material to an interconnect associated with a component. One such method involves placing a stencil in close proximity to an interconnect that extends over a cavity. An amount of protective material is placed on the stencil. A wiper is passed across the stencil. The wiper has an angle of attack of less than 50 degrees. At least a desired thickness of protective material is applied to the interconnect.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a representational view of a stencil application of a protective material to printhead electronic chip leads;

FIG. 2 shows a representational view of a prior art stencil application of a protective material to printhead electronic chip leads;

FIG. 3 shows a representational view of a squeegee for use in applying a protective material to printhead electronic chip leads in accordance with an exemplary embodiment of the present invention;

FIG. 4 shows a representational view of a prior art squeegee for use in applying a protective material to electronic chip leads;

FIG. 5 shows a representational view of a squeegee for use in applying a protective material to electronic chip leads in accordance with an exemplary embodiment of the present invention;

FIG. 6 shows a representational view of a squeegee with a rigid backer for use in applying a protective material to electronic chip leads in accordance with an exemplary embodiment of the present invention;

FIG. 7 shows a representational view of a first pass squeegee for use in applying a protective material to electronic chip leads in accordance with an exemplary embodiment of the present invention;

FIG. 8 shows a representational view of a second pass squeegee for use in applying a protective material to electronic chip leads in accordance with an exemplary embodiment of the present invention;

FIG. 9 shows a representational view of dual squeegees for use in applying a protective material to electronic chip leads in accordance with an exemplary embodiment of the present invention;

FIG. 10 shows a partial cross-sectional view of a prior art TAB assembly with the chip in a chip pocket, prior to application of a protective material; and

FIG. 11 shows a partial cross-sectional view of an exemplary TAB assembly with the chip in a chip pocket and protective material applied in accordance with an exemplary embodiment of the present invention.

Claims

1. A method for applying a protective material to an interconnect associated with a component comprising: placing a stencil in close proximity to an interconnect that extends over a cavity;placing an amount of protective material on the stencil; andpassing a wiper across the stencil, the wiper having an angle of attack of less than 50 degrees,

2. The method of claim 1 wherein the angle of attack is between about 10 degrees and about 40 degrees.

3. The method of claim 1 wherein the angle of attack is between about 15 degrees and about 35 degrees.

4. The method of claim 1 wherein the wiper has a hardness of less than about 90 durometer on a Shore D scale.

5. The method of claim 1 wherein the wiper has a rigid backing.

6. The method of claim 1 wherein the interconnect is a TAB beam extending from a TAB circuit to an ink jet printhead chip, the chip being received in a recessed area having at least one wall, wherein the cavity has a width defined by the distance between an edge of the chip and the at least one wall, and wherein the TAB circuit overhangs the cavity by less than about 0.6 mm.

7. The method of claim 6 wherein the width of the cavity is between about 0.2 to about 0.6 mm.

8. The method of claim 7 wherein the TAB circuit overhangs the cavity by between about 0.2 to about 0.4 mm.

9. The method of claim 8 wherein the cavity has a depth of between about 0.4 mm to about 0.66 mm.

10. The method of claim 6, further comprising applying an adhesive into the recessed cavity area prior to the chip being received in the recessed area, wherein the protective material and the adhesive are cured at substantially the same time.

11. The method of claim 10 wherein the protective material comprises an epoxy.

12. The method of claim 10, wherein the protective material has a viscosity of between about 30,000 cps and about 240,000 cps.

13. The method of claim 12, further comprising applying a force on the wiper, the force creating a pressure of less than about 160 psi on the protective material in contact with the wiper.

14. The method of claim 12, wherein the pressure is between about 40 to about 80 psi.

15. The method of claim 1, wherein the act of passing the wiper across the stencil comprises passing the wiper across the stencil at a speed of between about 25 mm/s to about 125 mm/s.

16. The method of claim 1, further comprising passing a second wiper across the stencil, the second wiper having an angle of attack that is greater than the angle of attack of the first wiper.

17. The method of claim 16 wherein the first and second wipers are mechanically connected.

18. The method of claim 17 wherein the first and second wipers are mounted in a force-feedback loop.

19. A method for applying a protective material to an interconnect associated with a component comprising: placing a stencil in close proximity to an interconnect that extends over a cavity;placing an amount of protective material on the stencil; andpassing a wiper across the stencil, the wiper having an angle of attack of less than 50 degrees and a hardness of less than about 90 durometer on a Shore D scale.

20. A method for applying a protective material to an interconnect associated with a component comprising: placing a stencil in close proximity to an interconnect that extends over a cavity;placing an amount of protective material on the stencil, the protective material having a viscosity of between about 30,000 cps and about 240,000 cps; andpassing a wiper across the stencil, the wiper having an angle of attack of less than 50 degrees and a hardness of less than about 70 durometer on a Shore D scale, and wherein a pressure is applied to the protective material by the wiper while it is passing across the stencil, the pressure being between about 0 to about 160 psi,