Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
1999-01-20
2001-03-06
Picard, Leo (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S692000, C361S702000, C361S707000, C361S709000, C257S718000, C174S034000, C174S016300, C165S080300
Reexamination Certificate
active
06198630
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to a method and apparatus for integrated circuit assembly. More particularly, the present invention relates to a method and apparatus for assembling a high speed, high density VLSI module that enables attachment, support, electromagnetic interference containment, and thermal management of the VLSI module.
1. Description of Related Art
The following applications are related to the present application, U.S. patent application entitled “METHOD AND APPARATUS FOR A MODULAR INTEGRATED APPARATUS FOR HEAT DISSIPATION, PROCESSOR INTEGRATION, ELECTRICAL INTERFACE, AND ELECTROMAGNETIC INTERFERENCE MANAGEMENT,” Ser. No. 09/195256, naming inventor S. Daniel Cromwell, et al., assigned to the assignee of the present invention; and U.S. Patent Application entitled “METHOD AND APPARATUS FOR PRECISE ALIGNMENT OF A CERAMIC MODULE TO A TEST APPARATUS,” Ser. No. 08/898327, naming inventors Rajendra D. Pendse, et al., assigned to the assignee of the present invention.
2. Background of the Invention
The use of increasingly high speed very large scale integrated circuit (VLSI) modules in computer systems has given rise to new assembly challenges related to their attachment, support, electromagnetic interference containment, and thermal management. For example high speed VLSI modules have input/output counts of 2000.
Often, due to the large thermally induced stresses that impact the long term reliability of solder joints, these high speed, high density VLSI module assemblies cannot employ standard solder techniques for connecting the VLSI modules to a circuit board. Therefore, there has been the emergence of interposer socket assembly techniques including a land grid array configuration of a VLSI module.
Another problem with high density, high speed VLSI modules is the difficulty of aligning the circuit board and an interposer socket assembly, and aligning the interposer socket assembly and the VLSI module. That is, as the pitch of a land grid array is reduced, the alignment becomes more difficult. It will be appreciated that the “pitch” of a land grid array refers to the distance from pad to pad, and that a “pad” refers to the individual contacts or connections in an interposer configuration.
Further, assembly space for high speed VLSI modules is limited. Also, high speed VLSI modules emit electromagnetic interference and heat that requires management. Therefore an efficient, high speed VLSI assembly should also include a tight Faraday Cage and a high performance heat dissipation device in the same package.
Further, improvements in high speed VLSI assemblies have been hindered by the difficulty of upgrading and handling of the VLSI module outside of a manufacturing or assembly environment.
Also, the difficulty of scaling high speed VLSI assemblies to large or small configurations has hindered improvements in high speed, high density VLSI module assembly.
SUMMARY OF THE INVENTION
The present invention is a method and apparatus for assembling a high speed, high density VLSI module in a computer system that enables attachment, support, electromagnetic interference containment, and thermal management of the VLSI module.
Accordingly it is an object of the invention to package a high speed, high density VLSI module within a limited space and in a single assembly that attaches, aligns, and manages electromagnetic interference and heat dissipation of the VLSI module, thereby efficiently using minimal space for the VLSI module assembly.
The VLSI module may include any general purpose application specific integrated circuit (ASIC) such as an area grid array or a socket-based VLSI module. However, as the I/O count has increased the ASIC package size has become too large for solder-attachment techniques and presents special problems that are solved by the present invention. Therefore, it is another object of the invention to align a land grid array of a circuit board and an interposer socket assembly, and to align the interposer socket assembly and a land grid array of the VLSI module in the single VLSI module assembly.
It is also an object of the invention to enable an alignment mechanism for the interposer socket assembly that is easy to manufacture and that supports tight tolerances that are required between the interposer socket assembly and the VLSI module. Therefore, the present embodiment employs the use of a solder ball and socket configuration between the VLSI module and the interposer socket assembly to manage the tight tolerance and close alignment requirements of the VLSI module.
It is also an object of the invention to enable ease-of-use in upgrading and handling of the VLSI module. For example in the present embodiment, due to the management of the alignment and orientation of the elements of the VLSI module assembly it is difficult to assemble the elements incorrectly.
It is another object of the invention to ensure that an even, controlled load is placed on the interposer socket interface thereby reducing the risk of damage to the interposer socket from overloaded connections between the land grid array of the VLSI module, the interposer socket assembly, and the land grid array of the circuit board. For instance the present embodiment may include the use of an overhead clamp and a single heat sink screw for a single load point that ensures an even load on the VLSI module. That is, by pressure from the overhead load clamp, the single heat sink screw applies load to a heat sink that is connected to the VLSI module. Therefore even loading may be accomplished by reusing the heat sink as a load spreader. It will be appreciated that the term “connect” refers to an element being held in proximity to another element while not bolting the elements together.
It is yet another object of the present invention to enable scaling of the VLSI module assembly to large or small configurations. For instance, the present invention novelly employs the overhead clamp that may be configured for large or small VLSI assemblies while maintaining an even load on the VLSI module.
It is another object of the invention to include a heat dissipation device in the VLSI module assembly. Therefore, the present embodiment includes a heat sink having heat fins and a heat sink base. The heat sink base is in optimal thermal proximity to the VLSI module to absorb heat, and to transfer the heat to the heat fins for efficient heat dissipation.
It is another object of the invention to integrate a Faraday Cage in the VLSI module assembly. Therefore, the present embodiment includes a Faraday Cage having the circuit board, an electromagnetic interference frame including a compliant electrically conductive electromagnetic interference gasket, and the heat sink base.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
REFERENCES:
patent: 4067237 (1978-01-01), Arcella
patent: 4120019 (1978-10-01), Arii et al.
patent: 4167031 (1979-09-01), Patel
patent: 4342069 (1982-07-01), Link
patent: 4376560 (1983-03-01), Olsson et al.
patent: 4506938 (1985-03-01), Madden
patent: 4540226 (1985-09-01), Thompson et al.
patent: 4563383 (1986-01-01), Kuneman et al.
patent: 4589716 (1986-05-01), Williams
patent: 4638854 (1987-01-01), Noren
patent: 4652973 (1987-03-01), Baker et al.
patent: 4675783 (1987-06-01), Murase et al.
patent: 4707726 (1987-11-01), Tinder
patent: 4829432 (1989-05-01), Hershberger et al.
patent: 4858093 (1989-08-01), Sturgeon
patent: 4874318 (1989-10-01), Spencer
patent: 4951740 (1990-08-01), Peterson et al.
patent: 4961633 (1990-10-01), Ibrahim et al.
patent: 4975825 (1990-12-01), Huss et al.
patent: 4978638 (1990-12-01), Buller et al.
patent: 5010292 (1991-04-01), Lyle, Jr.
patent: 5060112 (1991-10-01), Cocconi
patent: 5078622 (1992-01-01), Hunt et al.
patent: 5118925 (1992-06-01), Mims et al.
patent: 5131859 (1992-07-01), Bowen et al.
patent: 5136119 (1992-08-01), Leyland
patent: 5162974 (1992-1
Datskovsky Michael
Hewlett--Packard Company
Picard Leo
Smith Christine H.
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