International Business Machines Corporation

Piyas Bal Chowdhury

Kamal Kumar Sikka

Alfred Grill

Charles Leon Arvin

Jeffrey Allen Zitz

Sushumna Iruvanti

Steven Lorenz Wright

James John Kelly

Shidong Li

Thomas Edward Lombardi

A flip chip device and methods for fabrication are provided. An interconnect layer for a device include a plurality of solder bumps arranged within the interconnect layer. A first subset of the plurality of solder bumps has a first cross-sectional area, where the first subset is arranged along a first position at a first edge of the interconnect layer. A second subset of the plurality of solder bumps has a second cross-sectional area, where the second subset is arranged at a second position of the interconnect layer. A third subset of the plurality of solder bumps is arranged between the first position and the second position, where the third subset has a plurality of cross-sectional areas.

Electronic package with varying interconnects

Structural combinations of TIMs and methods of combining these TIMs in semiconductor packages are disclosed. An embodiment forms the structures by selectively metallizing a backside of a semiconductor chip (chip) on chip hot spots, placing a higher performance thermal interface material (TIM) on the metallized hot spots, selectively metalizing an underside of a lid in one or more metalized lid locations, and assembling a lid over the backside of the chip to create an assembly so that metalized lid locations are in contact with the higher performance TIMs. A lower performance TIM fills the region surrounding the higher performance TIM on the underside of the lid enclosing the chips. Disclosed are methods of disposing both solid and dispensable TIMs, curing and not curing the thermal interface, and structures to keep the TIMs in place while assembly the package and compressing dispensable TIMs. Alternative method steps are disclosed, such as: injecting the lower performance TIM through injection holes in a pre-assembled assembly, using solid preform TIMs with cutouts, and using high performance TIM structures that have collapsible rails to prevent lower performance TIM from spilling onto the surface of the higher performance TIM to permit good/bonding.

Hybrid TIMs for electronic package cooling

Growing community of inventors

Mountain View, CA, United States of America

Piyas Bal Chowdhury