James B Lance

US Patent:

56971486, Dec 16, 1997

Filed:

Aug 22, 1995

Appl. No.:

8/517977

Inventors:

James George Lance - Lake Worth FL
Robert Kenneth Doot - Boynton Beach FL
Karl Marcus Wahlfrid - Delray Beach FL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H05K 334

US Classification:

29840

Abstract:

A method for dispensing underfill material between a flip chip bonded to substrate. The method requires an underfill injection port to be drilled through the substrate prior to reflow such that underfill material can be dispensed between the flip chip and substrate through the port. After reflow is completed, a pressurized pump delivers a predetermined amount of underfill under hydraulic pressure through the underfill injection port between the flip chip and substrate. Once injected, the underfill migrates between the flip chip and substrate via capillary action pushing out any air around the joints.

US Patent:

56471238, Jul 15, 1997

Filed:

Oct 16, 1995

Appl. No.:

8/543543

Inventors:

Jonathon G. Greenwood - Boynton Beach FL
James G. Lance - Lake Worth FL
Robert Kenneth Doot - Boynton Beach FL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H05K 334

US Classification:

29840

Abstract:

A method and apparatus improves a distribution of an underfill material (504) applied between a flip chip die (202) and a circuit board (310) at a flip chip site (302) having a solder mask (308). An aperture (304) is formed (806) in the solder mask (308) by removing a predetermined majority of the solder mask (308) from the circuit board (310) within the flip chip site (302) before mounting the flip chip die (202). Then the flip chip die (202) is mounted (810) to the flip chip site (302). The underfill material (504) is then applied (812, 814, 816) such that the underfill material (504) flows into the aperture (304), thus improving the distribution of the underfill material (504).