Adhesive Compositions, Micro-Fluid Ejection Devices, and Methods for Attaching Micro-Fluid Ejection Heads

Abstract

Adhesive compositions, micro-fluid ejection devices, and methods for attaching micro-fluid ejection heads to devices. One such adhesive composition is provided for use in attaching a micro-fluid ejection head to a device, such as to reduce chip bowing and/or to decrease chip fragility upon curing of the adhesive. Such an exemplary composition may include one having from about 50.0 to about 95.0 percent by weight of at least one cross-linkable resin selected from the group consisting of epoxy resins, siloxane resins, urethane resins, and functionalized olefin resins; from about 0.1 to about 25.0 percent by weight of at least one thermal curative agent; and from about 0.0 to about 30.0 percent by weight filler, and exhibit a relatively low shear modulus upon curing (e.g., less than about 10.0 MPa at 25° C.).

Description

RELATED APPLICATIONS [0001] This application is a continuation of provisional application Ser. No. 60 / 743,920, filed Mar. 29, 2006.TECHNICAL FIELD [0002] The disclosure relates to adhesive compositions, and in one particular embodiment, to flexible compounds that can be cured for use as adhesives in micro-fluid ejection devices. BACKGROUND AND SUMMARY [0003] Micro-fluid ejection heads are useful for ejecting a variety of fluids including inks, cooling fluids, pharmaceuticals, lubricants and the like. A widely used micro-fluid ejection head is an inkjet print head used in an ink jet printer. Ink jet printers continue to be improved as the technology for making their micro-fluid ejection heads continues to advance. [0004] In the production of conventional thermal ink jet print cartridges for use in ink jet printers, one or more micro-fluid ejection heads are typically bonded to one or more chip pockets of an ejection device structure. A micro-fluid ejection head typically includes a f...

AI Technical Summary

Benefits of technology

[0012] Advantages of the exemplary embodiments may include, but are not limited to, a reduction in ejector chip substrate bow, an increase in ejector head durability, increased planarity of the ejector head, and the like. Other advantages might include the provision of adhesives having improved mechanical, adhesive, and ink resistive properties. Reduced stresses may be present in the ejector head substrates due to the presence of improved adhesives according to the disclosed embodiments.

Problems solved by technology

However, the micro-fluid ejection head and the ejection device structure typically have dissimilar coefficients of thermal expansion.

Conventional adhesive materials tend to be non-flexible and brittle after curing due to high temperatures required for curing and relatively high shear modulus of the adhesive materials upon curing.

Such properties may cause the adhesive materials to chip or crack.

It may also cause the components (e.g., micro-fluid ejection head and / or ejection device structure) to bow, chip, crack, or otherwise separate from one another, or to be less resilient to external forces (e.g., chips may be more prone to crack when dropped).

Upon cooling the device structure, the device structure contracts and, with a rigid, cured diebond material, induces high stress onto the ejection head to cause the aforementioned bowing, chipping, cracking, separating, etc.

Among other problems, such events can result in fluid leakage and poor adhesion as well as malfunctioning of the micro-fluid ejection heads, such as misdirected nozzles.

Moreover, attempts to make adhesive materials more flexible after curing often lead to adhesive materials that are less resistant to chemical degradation by the fluids being ejected.

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