Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package – For plural devices
Reexamination Certificate
2000-07-12
2001-05-15
Chaudhuri, Olik (Department: 2814)
Active solid-state devices (e.g., transistors, solid-state diode
Housing or package
For plural devices
C257S723000, C257S726000
Reexamination Certificate
active
06232659
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to means for encapsulating microelectronic devices. More specifically, the present invention provides an improved module which significantly increases the packaging density of microelectronic components.
BACKGROUND
The electronics industry has a continuing goal of increasing component packaging density in an effort to obtain increased functionality and consequent performance in smaller volumetric size. The principal roadblocks in meeting this goal have been the lack of industry standards for form factors and a flexible design which can be adapted to differing device types. Another significant impediment to increased packaging density has been the lack of an efficient means for dissipation of thermal energy generated by the devices.
One of the largest microelectronic device module markets is that related to dynamic random access memories (DRAM's). Since its introduction in 1983, the Single In-Line Memory Module or SIMM, disclosed generally in U.S. Pat. No's. 4,656,605 and 4,727,513, has grown to become the preferred module configuration for the DRAM semiconductor market. Among the advantages offered by the SIMM are the following: (1) its significant packaging density increase achieved over prior chip mounting configurations, (2) the convenience for modular replacement or upgrade, and (3) availability of multiple, low-cost manufacturing sources.
A continuing industry trend towards increasing performance and smaller size, however, foreshadows the need for an even more compact module than the present SIMM is able to provide. The quest for ever faster data processing and more compact, lightweight, thin, portable, hand-held electronic products necessitates newer semiconductor packaging schemes that enable aggregate assemblages of bare silicon devices to be interconnected together and mechanically protected inside a thin, lightweight module. Because of the handling difficulty and expense associated with repairing or replacing bare silicon chip devices, there is an anticipated need for an adaptable multichip module which provides a means for increasing packaging density while maintaining minimum expense. This present invention, described in greater detail below, seeks to satisfy this need within the electronic industry.
Though semiconductor memory devices occupy the vast majority of the module market today, there is also a growing requirement to modularize other semiconductor components including, but not limited to, microprocessor, application specific integrated circuits, telecommunication and other device types. Accordingly, the present invention provides an upgrade path for a greater number of interconnect pins/pads and improves the thermal dissipation characteristics over present day microelectronic device modules.
SUMMARY OF THE INVENTION
The present invention comprises various embodiments of an improved semiconductor module that houses a considerably larger number of semiconductor devices in a given volume. The module preferably is adapted for insertion into a mating socket and is removable for replacement, repair, configuration changes, or recycling. The preferred embodiments of the semiconductor module of the present invention are also backward compatible with existing SIMM sockets. Other embodiments are compatible with other standards, such as the PCMCIA (Personal Computer Memory Card International Association).
In one embodiment of the present invention, the module is broadly comprised of a molded module frame and a composite semiconductor substrate subassembly (abbreviated: “subassembly” or “subassembly(s)” or “subassemblies”) received in a cavity in the frame. The composite semiconductor substrate subassembly, or subassembly, comprises a plurality of semiconductor devices which are connected to electrical contacts on an edge of the molded module frame by a variety of configurations described herein.
In one embodiment of the invention, the subassembly includes a composite substrate which comprises a thin metal cover plate and thin laminate circuit which is bonded to the metal cover plate by a film adhesive. The composite substrate provides a mounting surface for the placement of semiconductor devices and their associated passive components. In some of the embodiments disclosed herein, the subassembly is permanently attached to the molded module frame by a rectangular ring formed from an anisotropic, electrically conductive adhesive material. In other embodiments, thin laminate circuits are applied to either side of a cover plate, and semiconductor devices are applied to the laminate circuits. A protective overcoat can be applied over the semiconductor devices, as desired. Other embodiments include folded or U-shaped laminate circuits with semiconductor devices and heat dissipating cover plates applied to respective surfaces, as desired. The various embodiments of the subassembly employed in the present invention also provides for a more efficient means for conducting thermal energy from the semiconductor devices.
REFERENCES:
patent: 4709300 (1987-11-01), Landis
patent: 5397916 (1995-03-01), Normington
patent: 5600178 (1997-02-01), Russell
patent: 5714802 (1998-02-01), Cloud et al.
patent: 5963427 (1999-10-01), Bollesen
Akin Gump Strauss Hauer & Feld L.L.P.
Cao Phat X.
Chaudhuri Olik
LandOfFree
Thin multichip module does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thin multichip module, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thin multichip module will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2563902