Shaw Ming Lee

US Patent:

6396135, May 28, 2002

Filed:

Dec 21, 2000

Appl. No.:

09/748309

Inventors:

Glenn C. Narvaez - Redwood City CA
Shaw Wei Lee - Cupertino CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 2302

US Classification:

257678, 257783, 438106

Abstract:

A number of techniques and substrate arrangements are described that working individually and in common have been found to significantly improve the environmental resistance of the resulting package. In one aspect, conductive pads (referred to herein as landing pads) on the top surface of a substrate are slightly undercut. This permits molding material applied during later packaging to flow into the undercut regions to help improve adhesion between the substrate and the molding material. In another aspect, metallic die attach pads formed on the substrate are patterned to provide better adhesion between the substrate and a solder mask that covers the die attach pads. More specifically, the metallic die attach pads are patterned to have a number of opening defined therein that leave corresponding portions of the substrate exposed. In substrates where a solder mask is applied over the die attach pad, the openings permit the solder mask to adhere directly to the substrate panel in the openings thereby strengthening the attachment of the solder mask to the substrate. In still another aspect, elongated slots are provided in the solder mask such that the slots expose one or more rows of adjacent landing pads instead of simply the landing pads themselves.

US Patent:

6475596, Nov 5, 2002

Filed:

Nov 30, 2000

Appl. No.:

09/726940

Inventors:

Hao-Ming Hsiao - San Ramon CA
Shaw Ming Lee - Danville CA
Robert Albert Buyny - Clayton CA
Cary Joseph Martin - Dublin CA

Assignee:

Hexcel Corporation - Pleasanton CA

International Classification:

B32B 502

US Classification:

428116, 428119, 428219, 428208, 428220, 442179, 442195

Abstract:

A core crush resistant prepreg for use in making a fiber reinforced composite panel structure is provided. The prepreg comprises a woven fabric consisting essentially of carbon fiber tow strands impregnated with a hardenable polymeric resin composition. Typically the fabric has an areal weight of from about 180 to about 205 grams per square meter. The prepreg has an average fiber tow aspect ratio of less than about 15. 4, a prepreg thickness of at least about 0. 245 mm, and a prepreg openness of at least about 1. 2 percent but less than about 6. 0 percent. Preferably, the resin composition is predominantly viscous in nature and has a tan value of between 0. 9 and 2. 0 at an elevated temperature between 70Â C. and 140Â C. , and an average epoxy functionality of greater than 2.

US Patent:

6663737, Dec 16, 2003

Filed:

Jun 7, 2001

Appl. No.:

09/876310

Inventors:

Hao-Ming Hsiao - San Ramon CA
Shaw Ming Lee - Danville CA
Robert Albert Buyny - Clayton CA
Cary Joseph Martin - Dublin CA

Assignee:

Hexcel Corporation - Dublin CA

International Classification:

B32B 312

US Classification:

156160, 156161, 427445, 428116, 442195, 442179, 442181

Abstract:

A core crush resistant prepreg for use in making a fiber reinforced composite panel structure is provided. The prepreg comprises a woven fabric consisting essentially of carbon fiber tow strands impregnated with a hardenable polymeric resin composition. Typically the fabric has an areal weight of from about 180 to about 205 grams per square meter. The prepreg has an average fiber tow aspect ratio of less than about 15. 4, a prepreg thickness of at least about 0. 245 mm, and a prepreg openness of at least about 1. 2 percent but less than about 6. 0 percent. Preferably, the resin composition is predominantly viscous in nature and has a tan value of between 0. 9 and 2. 0 at an elevated temperature between 70Â C. and 140Â C. , and an average epoxy functionality of greater than 2.

US Patent:

7087986, Aug 8, 2006

Filed:

Jun 18, 2004

Appl. No.:

10/871313

Inventors:

Jaime A. Bayan - Palo Alto CA, US
Ashok S. Prabhu - San Jose CA, US
Shaw Wei Lee - Cupertino CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 23/495
H01L 23/04

US Classification:

257676, 257698, 257E23037

Abstract:

A solder pad configuration for use in an IC package is described. Various embodiments of the invention describe IC packages, lead-frames, or substrate panels configured with generally noncircular solder pads at their bottom surfaces. The noncircular shapes allow for greater surface area than circular solder pads having diameters equal to a major dimension of the noncircular shapes, while maintaining the same metal-to-metal clearance between the pads and adjacent leads. This increased surface area provides for stronger and more reliable solder joints.

US Patent:

62616757, Jul 17, 2001

Filed:

Mar 23, 1999

Appl. No.:

9/273637

Inventors:

Hao-Ming Hsiao - San Ramon CA
Shaw Ming Lee - Danville CA
Robert Albert Buyny - Clayton CA
Cary Joseph Martin - Dublin CA

Assignee:

Hexcel Corporation - Pleasanton CA

International Classification:

B32B 502

US Classification:

428219

Abstract:

A core crush resistant prepreg for use in making a fiber reinforced composite panel structure is provided. The prepreg comprises a woven fabric consisting essentially of carbon fiber tow strands impregnated with a hardenable polymeric resin composition. Typically the fabric has an areal weight of from about 180 to about 205 grams per square meter. The prepreg has an average fiber tow aspect ratio of less than about 15. 4, a prepreg thickness of at least about 0. 245 mm, and a prepreg openness of at least about 1. 2 percent but less than about 6. 0 percent. Preferably, the resin composition is predominantly viscous in nature and has a tan. delta. value of between 0. 9 and 2. 0 at an elevated temperature between 70. degree. C. and 140. degree. C. , and an average epoxy functionality of greater than 2. A method for evaluating core crush resistance properties of a prepreg is also provided.