National Semiconductor Corporation

Seshadri Vikram

Ranjan J Mathew

Inderjit Singh

William Jeffrey Schaefer

An improved arrangement for attaching a heat sink to a flip chip type die is disclosed. More specifically, the heat sink is attached to the back surface of the flip chip die by a metallic solder material. Such an arrangement provides a good thermal conductivity between the die and the heat sink. In some embodiments, the die is mounted on a grid array type substrate in a flip chip arrangement such that the die contacts are coupled to adjacent I/O pads on the substrate. In another aspect, one or more metallic intermediate die attach layers are deposited over the back surface of the die to form a solderable die surface. The heat sink is then attached to the solderable die surface. This approach works well when the chosen solder does not adhere well to the semiconductor die material. In one preferred implementation the intermediate metallic layers include a barrier layer that is deposited over the back surface of the die and a solderable metallic layer that is deposited over the barrier layer. In a method aspect, the barrier and metallic layers may be deposited on the back side of a wafer during fabrication which provides the desired structure after dicing.

Thermally enhanced flip chip packaging arrangement

Apparatus are disclosed for Liquid Crystal Display (LCD) assemblies having a display device that is attached to a support substrate. The display device includes a die having a pixel array, and a transparent plate positioned over the die. An adhesive seal couples the die to the transparent plate. The seal together with the transparent plate and the die cooperate to define a sealed volume therebetween encompassing the pixel array. A liquid crystal material is disposed within the sealed volume. A support substrate is coupled to the transparent plate for support of the display device such that the die is substantially insulated from transmission of residual stresses induced by or acting upon the support substrate. Methods of reducing residual stresses in LCD assemblies are also provided.

Liquid crystal display assembly and method for reducing residual stresses

A wire bonding apparatus has a first support arrangement for supporting a first integrated circuit package component. A second support arrangement is configured to supporting a second integrated circuit package component. The second support arrangement includes at least a portion of a heating arrangement for heating certain portions of the second component. At least portions of the first support arrangement are thermally insulated from the second support arrangement such that at least certain portions of the first component may be maintained at a temperature substantially lower than the temperature of the heated portions of the second component. The apparatus may be used in method of forming a bonding wire for electrically connecting a first contact on a first integrated circuit package component to a second contact on a second integrated circuit package component. The method includes the steps of supporting and holding the first component and the second component in a desired position. Certain regions of the second component, including the second contact, are heated to a desired temperature while maintaining the temperature of at least certain portions of the first component, including the first contact, at a temperature substantially lower than the heated regions of the second component. A bonding wire is formed that electrically connects the first contact on the first component to the second contact on the second component.

Wire bonding methods and apparatus for heat sensitive metallization

A single gauge lead frame having a second support pad which is substantially a mirror image of a first support pad is disclosed. The second support pad is capable of being placed upon the first support pad. In this manner, the structural and thermally conductive advantages of a dual gauge lead frame is realized at a cost near a single gauge lead frame.

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Fremont, CA, United States of America

Seshadri Vikram