Cart 0

Sculptor, artist, and inventor

Georjia Motta

Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

Publication number US4801992 A
Publication type Grant
Application number US 06/936,570
Publication date Jan 31, 1989
Filing date Dec 1, 1986
Priority date Dec 1, 1986
Fee status Lapsed
Inventors Theodore R. Golubic
Original Assignee Motorola Inc.
Export Citation BiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Three dimensional interconnected integrated circuit
US 4801992 A
ABSTRACT
A three dimensional interconnected modular integrated circuit and method of manufacturing same are provided wherein the modular circuit comprises individual planar integrated circuits which are connected together and to an interconnect chip for mounting on a lead line package resulting in an increase in available integrated circuit surface area for a given footprint area.
IMAGES(2)
CLAIMS(16)
I claim:
1. A modular integrated circuit comprising a plurality of planar integrated circuits, each having at least two edges, joined at adjacent edges thereof wherein each of said planar integrated circuits contains a plurality of conductors formed therein and extending to at least one of said edges thereof for connecting said conductors of each of said planar integrated circuits to the conductors of at least one adjacent planar integrated circuit.
2. The modular integrated circuit of claim 1 wherein said planar integrated circuits are rectangular shaped
3. The modular integrated circuit of claim 2 comprising four of said planar integrated circuits connected to form a four-sided rectangular box.
4. The modular integrated circuit of claim 1 further comprising interconnect means for coupling at least one of the conductors from at least one edge of one of said planar integrated circuits to a lead package.
5. The modular integrated circuit of claim 4 wherein said interconnect means comprises a bumped chip.
6. The modular integrated circuit of claim 5 wherein said interconnect means further comprises a laminated area array tape.
7. The modular integrated circuit of claim 4 further comprising a lead package coupled to said interconnect means.
8. The modular integrated circuit of claim 7 further comprising a heat sink coupled to said planar integrated circuits.
9. A method for manufacturing a modular integrated circuit comprising the steps of:
forming a plurality of planar integrated circuits, each having a plurality of conductors extending to at least one edge thereof, on a plurality of wafers;
cutting said wafers into individual planar integrated circuits; and
connecting adjacent edges, and the conductors which extend thereto, of at least two of said planar integrated circuits to form a modular integrated circuit.
10. The method of claim 9 wherein said cutting step comprises sawing said wafers with a saw blade having an edge shaped to form cut edges on said planar integrated circuits such that when adjacent edges of said planar integrated circuits are joined a bevel joint is formed.
11. The method of claim 9 further comprising the step of connecting at least one edge of an interconnect chip, having at least one edge and a plurality of conductors extending to said at least one edge thereof, to at least one edge of at least one of said planar integrated circuits such that said conductors of said interconnect chip are connected to conductors of said at least one planar integrated circuit.
12. The method of claim 11 further comprising the step of connecting a lead package to said interconnect chip.
13. A method for manufacturing a modular integrated circuit comprising the steps of:
forming a plurality of adjacent planar integrated circuits, having at least one common edge and at least two other edges thereof, on a single wafer wherein each of said planar integrated circuits contains a plurality of conductors extending across said at least one common edge thereof to connect to an adjacent planar integrated circuit;
cutting said wafer along said at least one common edge and along said at least two other edges of said plurality of planar integrated circuits such that said plurality of conductors remains intact across said at least one common edge;
folding said plurality of planar integrated circuits along said at least one common edge; and
connecting said at least two other edges to form a modular integrated circuit.
14. The method of claim 13 wherein said cutting step comprises sawing with a saw blade having an edge shaped to form cut edges on said planar integrated circuits such that when said fold is made along said common edge and when said at least two other edges are connected, bevel joints are formed.
15. The method of claim 13 further comprising the step of connecting at least one edge of an interconnect chip, having at least one edge and a plurality of conductors extending to said at least one edge thereof, to at least one edge of at least one of said planar integrated circuits such that said conductors of said interconnect chip are connected to conductors of said at least one planar integrated circuit.
16. The method of claim 15 further comprising the step of connecting a lead package to said interconnect chip.
DESCRIPTION
BACKGROUND OF THE INVENTION

This invention relates, in general, to three dimensional integrated circuits. More particularly, the present invention relates to a specific configuration for three dimensional integrated circuits and a method of constructing same. In order to increase circuit density, semiconductor manufacturers have continued to reduce the size of various integrated circuit elements and interconnections to the point where the limits of current technology are being reached. In order to decrease run length and increase circuit density, various methods have been explored to interconnect a plurality of integrated circuit chips without the use of a circuit board. Some of the methods proposed to date include wafer scale integration, stacking individual devices horizontally and stacking individual devices vertically.

It would, therefore, be advantageous to combine a number of integrated circuits in a three dimensional interconnected module such that for a given device footprint the total integrated circuit surface area would increase by a factor of 2, 3, 4 or more. This increased circuit area could be used to either add additional functions to a given circuit or provide redundancy in areas where desired. It would be desirable to accomplish this increase in integrated circuit area while at least retaining, if not improving, the heat dissipation capability of the original circuit. In addition, a method should be provided wherein the individual circuit elements may be easily interconnected among themselves and to any external circuits. Such an arrangement would also decrease the run length between the individual circuit chips thereby reducing both the power required for transmitting signals between the individual chips and the time required for such signals to be transmitted between such chips. In those devices where run lengths are not critical, expanding the formats of existing devices would restore greater line widths and therefore result in greater yields.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a three dimensional interconnected modular integrated circuit.

It is a further object of the present invention to provide a modular integrated circuit having increased circuit density for a given available mounting surface area.

A still further object of the present invention is to provide a modular integrated circuit having a cooling capacity at least equal to that of a flat integrated circuit having the same mounting surface area.

Yet another object of the present invention is to provide a method for interconnecting a number of separate or combined discrete and/or integrated circuit chips which results in increased circuit density, reduced interconnect lengths, improved heat dissipation, and reduced board count or size.

The foregoing and other objects are achieved in the present invention wherein there is provided a method of constructing a three dimensional modular integrated circuit on a wafer, forming moat regions between individual integrated circuits and filling said moat regions with isolation regions. Conductive material is applied to each individual integrated circuit in specific patterns in order to bring interconnection lines across said moat regions.

The wafers containing the individual circuits are then cut along the surface opposite the moat regions with a saw blade having a 90 degree included angle in order to form 45 degree beveled edges on the edges of the individual integrated circuit chips. The individual chips are then assembled on a hollow core such that the 45 degree beveled edges of adjacent chips are aligned.

The individual chips are bonded to the hollow core and the conductive lines are connected at adjacent corners. A fifth chip having bumped connections is connected to the cube resulting from interconnecting four of the individual circuit chips around the hollow core. The edges of the bumped chip are beveled at a 45 degree angle to mate with the four integrated circuit chips and their corresponding conductive lines. The resultant cube shaped integrated circuit has a circuit surface area four times that of one of the individual circuit chips but has the same footprint area as one individual chip.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and objects of the present invention and the manner of obtaining them will become apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an enlarged cross-sectional view illustrating a portion of a wafer having integrated circuits and moat regions used in accordance with the present invention;

FIG. 2 is an enlarged cross-sectional view illustrating the sawing of the substrate at the moat region;

FIG. 3 is an isometric view of a hollow core used to support the individual integrated circuit chips;

FIG. 4 is an isometric view of the hollow core and the attached integrated circuit chips;

FIG. 5 is an isometric view of a portion of an assembled cube module showing the bumped chip;

FIG. 6 illustrates tape automated bonding as a method for assembling the integrated circuit module;

FIG. 7 is a cross-sectional view illustrating the integrated circuit cube bonded to a package; and

FIG. 8 is an isometric view of a completed cube integrated circuit module.

DESCRIPTION OF A PREFERRED EMBODIMENT

The three dimensional integrated circuit of the present invention comprises individual integrated circuit chips which are formed and assembled in the following manner:

As shown in FIG. 1, individual integrated circuit chips are formed on substrate 10 of wafer 11 in a manner known to those skilled in the art. Integrated circuit region 12, while shown as a single layer, may consist of multiple layers as required to produce the desired integrated circuit. It is also contemplated that integrated circuit region 12 may consist of a single discrete device. Moat regions 13 are formed in substrate 10 by conventional means such as etching. Moat region 13 is then filled with isolation material to form isolation region 14. Once the individual integrated circuits 12 have been formed, conductive material is applied in specific patterns as desired in order to bring interconnection lines across moat region 13. This conductive material is shown, for example as metal line 16 in FIG. 1.

Once the individual integrated chips have been formed on wafer 11, as shown in FIG. 1, the wafer is inverted and may be attached to a mylar layer 18 in order to facilitate handling. Individual circuit chips 19 are then formed by cutting the wafer 11 along moat regions 13 which were created as described above. The included angle of the edge of the saw blade 20 should be as required to form the appropriate miter angle between adjacent circuit chips when they have been mounted into the cube. In the case of a four sided cubic arrangement as shown in FIG. 4, the angle of this edge of the saw blade should be 90° to produce a 45° angle on the adjoining edges of each of the adjacent individual circuit chips.

The individual circuit chips 19 thus produced are then assembled together over a hollow core such as that shown in FIG. 3. This core may provide both a mounting surface for the individual circuit chips and a heat transfer device for dissipating heat from the individual circuit chips. As shown in FIG. 4, the individual chips 19 are mounted such that the 45° bevelled edges contact each other and the conducting lines of adjacent individual circuit chips are aligned.

As illustrated in FIG. 4, the individual chips 19 are bonded to the hollow core using epoxy or the like. While the individual chips 19 need not be identical the mating edges along corner 40 should be of the same length and the conducting lines 16 should be arranged to align with those of an adjacent chip. The conductive lines 16 from each chip may be connected at adjacent corners using conductive paste, laser fusion, arc spot weld or ultrasonic weld. In an alternative embodiment the individual circuit chips 19 are simply attached to each other at adjacent corners using an adhesive means and the hollow core 30 is not used. In yet another embodiment, first, second, third and fourth individual circuit elements 19 are laid out in a linear fashion along wafer 11 and the cut illustrated in FIG. 2 is made to extend only through isolation layer 14 and not through metal line layer 16. Thus, adjacent circuit elements 19 may be connected simply by folding into the cube shape using intact metal lines 16 as a hinge at three adjacent corners. The remaining fourth corner must then be fastened as indicated above using any conventional adhesive means.

The four integrated circuit chips 19 thus assembled are now attached to a fifth side of a cube which comprises a bumped chip with various interconnect lines to the other four integrated circuit chips. Again the conducting lines 16 on each of the four integrated circuits chips are connected to the bumped chip using conductive paste, laser fusion, arc spot weld or ultrasonic weld. The resultant integrated circuit cube 45 comprises four separate integrated circuit chips which are interconnected both among themselves and to the bumped chip which forms the fifth side of a modular integrated circuit.

FIG. 6 illustrates tape automated bonding as one method for assembling the thus assembled integrated circuit module to a conventional lead package. Integrated circuit cube 45 is bump mounted to a laminated area array tape 46 which is in turn mounted to lead line package 48. In the alternative integrated circuit cube 45 could be surface mounted to a lead line area array integrated into a board or hybrid-like layered substrate.

In FIG. 7 there is shown the assembled integrated circuit cube 45 mounted to lead line package 48. In addition there is shown cap 42 which contacts core 30 and package seal ring 47 and provides a heat conduction path to lead line package 48. The opening of core 30 remains as an additional method for cooling of integrated circuit cube 45. In addition to providing a heat conduction path, cap 42 may also provide a method of physically and hermetically protecting the integrated circuits mounted on cube 45. The completed circuit module is as shown in FIG. 8. This completed circuit module will provide four times the circuit area of a flat integrated circuit mounted on the same package.

Alternative embodiments could be utilized to provide either two or three times the circuit area of a footprint by altering the geometric configuration. For example, a tent-shaped configuration could be utilized wherein the two sides of the tent would be separate integrated circuit chips 19 and the floor of the tent would be a bumped chip. In a similar fashion the four sided box, similar to that of FIG. 4, could be utilized wherein three of the sides of the box are separate integrated circuit elements 19 and the fourth side of the box is a bumped chip which is mounted to the lead line package. Likewise, there could be alternative embodiments with five or more separate integrated circuit elements arranged in various geometric configurations.

The above description is given by way of example only. Changes in form and details may be made by one skilled in the art without departing from scope of the invention.

PATENT CITATIONS
Cited Patent Filing date Publication date Applicant Title
US3880493 * Dec 28, 1973 Apr 29, 1975 Burroughs Corp Capacitor socket for a dual-in-line package
US4295924 * Dec 17, 1979 Oct 20, 1981 International Business Machines Corporation Method for providing self-aligned conductor in a V-groove device
REFERENCED BY
Citing Patent Filing date Publication date Applicant Title
US5025306 * Aug 9, 1988 Jun 18, 1991 Texas Instruments Incorporated Assembly of semiconductor chips
US5218515 * Mar 13, 1992 Jun 8, 1993 The United States Of America As Represented By The United States Department Of Energy Microchannel cooling of face down bonded chips
US5241450 * Mar 13, 1992 Aug 31, 1993 The United States Of America As Represented By The United States Department Of Energy Three dimensional, multi-chip module
US5362986 * Aug 19, 1993 Nov 8, 1994 International Business Machines Corporation Vertical chip mount memory package with packaging substrate and memory chip pairs
US5393705 * Feb 22, 1994 Feb 28, 1995 Nec Corporation Molded semiconductor device using intermediate lead pattern on film carrier formed from lattice pattern commonly available for devices and process of fabrication thereof
US5426563 * Nov 22, 1993 Jun 20, 1995 Fujitsu Limited Three-dimensional multichip module
US5426566 * Jan 4, 1993 Jun 20, 1995 International Business Machines Corporation Multichip integrated circuit packages and systems
US5454160 * Dec 3, 1993 Oct 3, 1995 Ncr Corporation Apparatus and method for stacking integrated circuit devices
US5481133 * Dec 29, 1994 Jan 2, 1996 United Microelectronics Corporation Three-dimensional multichip package
US5502667 * Sep 13, 1993 Mar 26, 1996 International Business Machines Corporation Integrated multichip memory module structure
US5561622 * Sep 13, 1993 Oct 1, 1996 International Business Machines Corporation Integrated memory cube structure
US5567654 * Sep 28, 1994 Oct 22, 1996 International Business Machines Corporation Method and workpiece for connecting a thin layer to a monolithic electronic module's surface and associated module packaging
US5637912 * May 31, 1996 Jun 10, 1997 International Business Machines Corporation Three-dimensional monolithic electronic module having stacked planar arrays of integrated circuit chips
US5648684 * Jul 26, 1995 Jul 15, 1997 International Business Machines Corporation Endcap chip with conductive, monolithic L-connect for multichip stack
US5655290 * Jan 30, 1995 Aug 12, 1997 Fujitsu Limited Method for making a three-dimensional multichip module
US5656553 * May 30, 1996 Aug 12, 1997 International Business Machines Corporation Method for forming a monolithic electronic module by dicing wafer stacks
US5657206 * Jan 19, 1995 Aug 12, 1997 Cubic Memory, Inc. Conductive epoxy flip-chip package and method
US5661087 * Jun 7, 1995 Aug 26, 1997 Cubic Memory, Inc. Vertical interconnect process for silicon segments
US5698895 * Jan 20, 1995 Dec 16, 1997 Cubic Memory, Inc. Silicon segment programming method and apparatus
US5702984 * Nov 14, 1996 Dec 30, 1997 International Business Machines Corporation Integrated mulitchip memory module, structure and fabrication
US5715144 * May 24, 1996 Feb 3, 1998 International Business Machines Corporation Multi-layer, multi-chip pyramid and circuit board structure
US5767580 * Dec 18, 1995 Jun 16, 1998 Lsi Logic Corporation Systems having shaped, self-aligning micro-bump structures
US5781031 * Nov 21, 1995 Jul 14, 1998 International Business Machines Corporation Programmable logic array
US5786237 * Aug 16, 1995 Jul 28, 1998 International Business Machines Corporation Method for forming a monolithic electronic module by stacking planar arrays of integrated circuit chips
US5818748 * Nov 21, 1995 Oct 6, 1998 International Business Machines Corporation Chip function separation onto separate stacked chips
US5837566 * Apr 24, 1997 Nov 17, 1998 Cubic Memory, Inc. Vertical interconnect process for silicon segments
US5854534 * Nov 16, 1995 Dec 29, 1998 Fujitsu Limited Controlled impedence interposer substrate
US5891761 * Aug 22, 1997 Apr 6, 1999 Cubic Memory, Inc. Method for forming vertical interconnect process for silicon segments with thermally conductive epoxy preform
US5903059 * Nov 21, 1995 May 11, 1999 International Business Machines Corporation Microconnectors
US5907903 * Jan 8, 1998 Jun 1, 1999 International Business Machines Corporation Multi-layer-multi-chip pyramid and circuit board structure and method of forming same
US5953214 * May 24, 1996 Sep 14, 1999 International Business Machines Corporation Dual substrate package assembly coupled to a conducting member
US5953276 * Dec 18, 1997 Sep 14, 1999 Micron Technology, Inc. Fully-differential amplifier
US5978298 * Sep 17, 1998 Nov 2, 1999 Micron Technology, Inc. Shared pull-up and selection circuitry for programmable cells such as antifuse cells
US5994170 * Apr 25, 1997 Nov 30, 1999 Cubic Memory, Inc. Silicon segment programming method
US6011742 * Aug 20, 1997 Jan 4, 2000 Micron Technology, Inc. Shared pull-up and selection circuitry for programmable cells such as antifuse cells
US6046911 * Feb 19, 1997 Apr 4, 2000 International Business Machines Corporation Dual substrate package assembly having dielectric member engaging contacts at only three locations
US6080596 * Aug 22, 1997 Jun 27, 2000 Cubic Memory Inc. Method for forming vertical interconnect process for silicon segments with dielectric isolation
US6102710 * Apr 30, 1998 Aug 15, 2000 Fujitsu Limited Controlled impedance interposer substrate and method of making
US6104209 * Aug 27, 1998 Aug 15, 2000 Micron Technology, Inc. Low skew differential receiver with disable feature
US6124633 * Aug 22, 1997 Sep 26, 2000 Cubic Memory Vertical interconnect process for silicon segments with thermally conductive epoxy preform
US6137691 * Sep 10, 1998 Oct 24, 2000 Samsung Electronics Co., Ltd. Three dimensional composite circuit board
US6188126 Apr 24, 1997 Feb 13, 2001 Cubic Memory Inc. Vertical interconnect process for silicon segments
US6255726 Aug 21, 1997 Jul 3, 2001 Cubic Memory, Inc. Vertical interconnect process for silicon segments with dielectric isolation
US6256234 May 23, 2000 Jul 3, 2001 Micron Technology, Inc. Low skew differential receiver with disable feature
US6372527 Sep 8, 1999 Apr 16, 2002 Tessera, Inc. Methods of making semiconductor chip assemblies
US6393378 Jan 16, 2001 May 21, 2002 Micron Technology, Inc. Circuit and method for specifying performance parameters in integrated circuits
US6465893 Oct 19, 2000 Oct 15, 2002 Tessera, Inc. Stacked chip assembly
US6486528 Aug 23, 1999 Nov 26, 2002 Vertical Circuits, Inc. Silicon segment programming apparatus and three terminal fuse configuration
US6710435 Jul 24, 2002 Mar 23, 2004 Denso Corporation Semiconductor device arrangement and method of fabricating the same
US7098078 Nov 21, 2002 Aug 29, 2006 Tessera, Inc. Microelectronic component and assembly having leads with offset portions
US7198969 Sep 7, 2000 Apr 3, 2007 Tessera, Inc. Semiconductor chip assemblies, methods of making same and components for same
US7215018 Mar 25, 2005 May 8, 2007 Vertical Circuits, Inc. Stacked die BGA or LGA component assembly
US7271481 May 26, 2006 Sep 18, 2007 Tessera, Inc. Microelectronic component and assembly having leads with offset portions
US7291910 Jun 5, 2002 Nov 6, 2007 Tessera, Inc. Semiconductor chip assemblies, methods of making same and components for same
US7705432 Dec 17, 2004 Apr 27, 2010 Vertical Circuits, Inc. Three dimensional six surface conformal die coating
US8729690 Dec 27, 2012 May 20, 2014 Invensas Corporation Assembly having stacked die mounted on substrate
US20010030370 * Apr 6, 2001 Oct 18, 2001 Khandros Igor Y. Microelectronic assembly having encapsulated wire bonding leads
US20020155728 * Jun 5, 2002 Oct 24, 2002 Tessera, Inc. Semiconductor chip assemblies, methods of making same and components for same
US20030168253 * Nov 21, 2002 Sep 11, 2003 Tessera, Inc. Microelectronic component and assembly having leads with offset portions
US20040105244 * Aug 6, 2003 Jun 3, 2004 Ilyas Mohammed Lead assemblies with offset portions and microelectronic assemblies with leads having offset portions
US20050087855 * Nov 16, 2004 Apr 28, 2005 Tessera, Inc. Microelectronic component and assembly having leads with offset portions
US20050224952 * Dec 17, 2004 Oct 13, 2005 Al Vindasius Three dimensional six surface conformal die coating
US20070138607 * Dec 28, 2006 Jun 21, 2007 Tessera, Inc. Lead assemblies with offset portions and microelectronic assemblies with leads having offset portions
US20070290377 * Aug 31, 2007 Dec 20, 2007 Vertical Circuits, Inc. Three Dimensional Six Surface Conformal Die Coating
US20140160692 * Dec 5, 2013 Jun 12, 2014 Pc Concepts Limited Method for surface decoration of an object with 3-dimensional geometry and the object obtained therefrom
DE4239857A1 * Nov 27, 1992 Jun 1, 1994 Abb Research Ltd Power semiconductor module with semiconductor chip having two main surfaces - has conductive tracks contacted by terminals on second main surfaces via flat contact strips
Three dimensional interconnected integrated circuit
US 4801992 A
ABSTRACT
A three dimensional interconnected modular integrated circuit and method of manufacturing same are provided wherein the modular circuit comprises individual planar integrated circuits which are connected together and to an interconnect chip for mounting on a lead line package resulting in an increase in available integrated circuit surface area for a given footprint area.
IMAGES(2)


Older Post