Patent Number: 7,087,304

Title: Polysulfide-based toughening agents, compositions containing same and methods for the use thereof

Abstract: In accordance with the present invention, there are provided toughening agents which are useful for improving the performance properties of epoxy-based adhesive formulations. For example, epoxidized polysulfides have been found to be useful toughening agents of component level underfill adhesive compositions. Invention materials are liquid rubbers which provide improved fracture toughness while maintaining satisfactory capillary flow properties. Invention materials can be synthesized in neat (solventless) reactions from readily available low-cost raw materials and isolated in high yields. They have linear and branched telechelic structures with terminal epoxide functional groups, and are prepared without substantially increasing the molecular weight of the starting polysulfide materials. Invention materials are compatible with common epoxy formulations and may be used without purification. At low levels of incorporation, they provide adhesives that meet the minimum fracture toughness (Gq>2.0 lb/in) and capillary flow specifications (flow time<180 seconds) for many commercial underfill applications. In accordance with a further embodiment of the present invention, there are provided adhesive compositions comprising invention compounds and methods for use thereof. In additional embodiments of the present invention, there are provided methods for the preparation of invention toughening agents, methods for adhesively attaching a device to a substrate, and assemblies comprising first article(s) adhered to second article(s).

Inventors: Woods; John G. (Farmington, CT), Luh; Yuhshi (Orange, CT), Konarski; Mark M. (Old Saybrook, CT)

Assignee: Henkel Corporation

International Classification: B32B 27/38 (20060101); B32B 7/12 (20060101); C08L 63/00 (20060101); C09J 163/00 (20060101); H01L 21/56 (20060101)

Expiration Date: 8/08/02018