Multi-Electronic Device Package Comprising at Least Two Substrates and at Least Four Layers of Electrically Conductive Circuitry

This invention relates to electronic device packages for multiple electronic devices, such as integrated circuits, memory chips, or the like.

Multiple chip module (MM) designs have responded to the need for increasing the number of electronic devices, such as integrated circuits or memory chips, within smaller areas. Initially, MCM technology connected chips or dies in an unpackaged, bare form in an XY plane and not along a Z axis. MCM technology has now allowed the interconnection and stacking of bare chips along the Z axis. Three-dimensional MCM packaging of this type offers higher chip density and less required interconnect density than two-dimensional multiple chip substrates. For an example of one such three-dimensional multi-chip module, see U. S. Pat. No. 5,222,014. While such designs have greatly improved chip density, further refinements in such designs are needed to improve the management of heat and also to further reduce the profile of the multi-chip module, in other words, to further increase chip density while managing and dissipating the heat generated from the multiple chips.

Another disadvantage of two-dimensional MCMs occurs during burn-in. Burn-in is performed to screen out weak chips or dice and validate that each die in a MCM is a known good die (KGD). If a two-dimensional MCM fails during burn-in, the entire module must be discharged or repaired using a costly removal procedure wherein the defective die is removed and replaced with a known good die. Thus, as the number of dice in a two-dimensional MCM increases, the yield for functional modules decreases. By stacking two-dimensional MCMs to create a three-dimensional MCM, each two-dimensional MCM layer can be tested and burned in separately to validate that each two-dimensional MCM layer and dice there are known good. Thus, the resulting yields for functional three-dimensional modules are greater than two-dimensional modules having equivalent chip or circuit densities. Also, by performing burn-in at the MCM level, known good die testing of each die can be avoided.

Accordingly, the present invention is directed to a multi-electronic device package comprising a first substrate having a first surface and opposed second surface wherein the first substrate includes a first opening and a first layer of electrically conductive circuitry formed on the first surface of the first substrate. The electronic device package further includes a second substrate having a first surface and an opposed second surface wherein the second substrate includes a second opening and a second layer of electrically conductive circuitry formed on the second surface of the second suite. A thermally and electrically conductive plane having a first surface and an opposed second surface is included. The plane is positioned between the first substrate and the second substrate and covers the first and second openings. A first electronic device is secured to the first surface of the plane such that the first electronic device is positioned within the first opening and wherein the first electronic device is electrically coupled to the first layer of circuitry. The electronic device package further includes a second electronic device secured to the second surface of the plane such that the second electronic device is positioned within the second opening. The second electronic device is electrically coupled to the second layer of circuitry, and the first layer of circuitry is electrically coupled to the second layer of circuitry. The first layer of circuitry is adapted for electrical coupling to a second electronic device package, and the second layer of circuitry is adapted for electrical coupling to a third external circuitized substrate.

The present invention is also directed to multi-electronic device package comprising a first substrate having a first surface and an opposed second surface wherein the first surface includes a first cavity extending from the first surface partially into the first substrate. A first layer of electrically conductive circuitry is formed on the first surface of the first substrate, and a second layer of electrically conductive circuitry is formed on the second surface of the first substrate wherein the second layer of circuitry is electrically coupled to the first layer of the circuitry and wherein the second layer of circuitry is adapted for electrical coupling to a third external circuitized substrate. The electronic device package further includes a first electronic device secured to the first substrate such that the first electronic device is positioned within the first cavity. The first electronic device is electrically coupled to the first layer of circuitry. A second substrate having a first surface and an opposed second surface is included, and a third layer of electrically conductive circuitry is formed on the second surface of the second substrate. The electronic device package further includes a second electronic device coupled to the second substrate wherein the second electronic device is electrically coupled to the third layer of circuitry and wherein the first and second substrates are bonded together along a common interface such that the second electronic device and the second surface of the second substrate faces the first electronic device and the first surface of the first substrate and wherein said first layer of circuitry is electrically coupled to the third layer of circuitry.

The present invention is also directed to a multi-electronic device package comprising a first substrate having a first surface and an opposed second surface; a first layer of electrically conductive circuitry formed on the first surface of the first substrate; a second layer of electrically conductive circuitry formed on the second surface of the first substrate wherein the second layer of circuitry is electrically coupled to said first layer of circuitry and wherein the second layer of circuitry is adapted for electrical coupling to a third external circuitized substrate. The electronic device package further comprises an electronic device secured to the first substrate and electrically coupled to the first layer of circuitry; a second substrate having a first surface and an opposed second surface; a third layer of electrically conductive circuitry formed on the first surface of the second substrate; a second electronic device coupled to the second substrate wherein the second electronic device is electrically coupled to the third layer of circuitry; a fourth layer of electrically conductive circuitry formed on the second surface of the second substrate wherein the fourth layer of circuitry is electrically coupled to the third layer of circuitry; and a first encapsulant covering the first electronic device and a portion of the first layer of circuitry. The second substrate includes a cavity extending from the second surface of the second substrate partially into the second substrate wherein the first and second substrates are bonded together along a common interface such that the second surface of the second substrate faces the first surface of the first substrate and at least a portion of the encapsulant extends into the cavity to thereby decrease the distance between the second surface of the second substrate and the first surface of the first substrate.

The primary advantage of the present invention is an improved multi-electronic device package design having increased chip density, lower overall profile, and greater heat dissipation performance than prior art multi-chip module designs.

Also, the present invention provides the advantage of avoiding the need for known good die (KGD) to manufacture MCMs.

FIG. 1 is a perspective view of a multi-electronic device according to the present invention.

FIG. 2 is a cross-sectional view of the multi-electronic device package of FIG. 1.

FIG. 3 is a perspective view of an alternative embodiment of a multi-electronic device package according to the present invention.

FIG. 4 is a cross-sectional view of the multi-electronic device package of FIG. 3.

FIG. 5 is a perspective view of a second alternative embodiment of a multi-electronic device package according to the present invention.

FIG. 6 is a cross-sectional view of the multi-electronic device package of FIG. 5.

Referring to FIGS. 1 and 2, a multi-electronic device package 10 according to the invention is shown. Multi-electronic device package 10 is also known as a ball grid array (BGA) package. Multi-electronic device package 10 includes a first substrate 12 having a first surface 14 and an opposed second surface 16. Substrate 12 is a dielectric material, i.e., a non-electrically conductive material such as a pre-peg comprising epoxy resin impregnated with glass fabric. First substrate 12 includes a first opening 18. A first layer of electrically conductive circuitry 20 is formed on first surface 14 of first substrate 12. Multi-electronic device package 10 further includes a second substrate 22 having a first surface 24 and an opposed second surface 26. Second substrate 22 is preferably also made from pre-peg comprising epoxy resin impregnated with glass fabric. The second substrate 22 includes a second opening 28. A thermally and electrically conductive plane 30 having a first 32 and an opposed second surface 34 is provided. Plane 30 is positioned between first substrate 12 and second substrate 22 and covers first and second openings 18, 28. Plane 30 is preferably a copper foil sheet, but it will be appreciated that plane 30 may be constructed from other thermally and electrically conductive materials such as aluminum or the like. The first electronic device 36 is secured to first surface 32 of plane 30 such that first electronic device 36 is positioned within first opening 18. First electronic device 36 is electrically coupled to first layer of circuitry 20. First electronic device 36 may be any electrical based component, such as an integrated circuit, memory chip, and/or semiconductor die having contacts 38a, 38b.

A second electronic device 40 is secured to second surface 34 of plane 30 such that second electronic device 40 is positioned within second opening 28. Second electronic device 40 is electrically coupled to a second layer of circuitry 27 formed on second surface 34 of second substrate 22 via contacts 38c, 38d. First layer of circuitry 20 is electrically coupled to second layer of circuitry 27, and first layer of circuitry 20 is adapted for electrical coupling to a second electronic package 10'. Also, second layer of circuitry 27 is adapted for elected coupling to a third external circuitized substrate (not shown). It will be appreciated that although second electronic package 10' is shown in phantom as being identical to multi-electronic device package 10, second electronic package 10' can take on various other forms such as those designs already described in the prior art and/or those designs to be described in FIGS. 3-6.

Still referring to FIGS. 1 and 2, multi-electronic device package 10 further comprises a plurality of plated through holes 42, 44, 46, 48, 50, 52 extending through first and second substrates 12, 22 and plane 30 for electrically coupling first and second layers of circuitry 20, 27. Second layer of circuitry 27 includes a plurality of solder ball pads 54, 56, 58, 60, 62, 64. Solder balls 66, 68, 70, 72, 74, 76 are coupled to or soldered to solder ball pads 54, 56, 58, 60, 62, 64, respectively, to electrically couple second layer of circuitry 27 to the third external circuitized substrate (not shown) as well known in the art. Second electronic package 10' includes, at a minimum, the following parts: a fourth substrate 22' having a first surface 24' and a second surface 26' opposed to first surface 24'; a third layer of electrically conductive circuitry 27' formed on second surface 26' of fourth substrate 22'; and a third electronic device 40' coupled to fourth substrate 22' and electrically coupled to third layer of circuitry 27'. Second electronic device package 10' is stacked on top of multi-electronic device package 10 and attached thereto. Third layer of circuitry 27' includes a plurality of solder ball pads 54', 56', 58', 60', 62', and 64'. Few layer of circuitry 20 includes a corresponding solder ball pad 78, 80, 82, 84, 86, and 88 for each solder ball pad 54', 56', 58', 60', 62', and 64' of third layer of circuitry 27'. Solder balls 90, 92, 94, 96, 98, and 100 are coupled to each solder ball pad 54', 56', 58', 60', 62', and 64', respectively, and each corresponding solder ball pad 78, 80, 82, 84, 86, and 88 to attach multi-electronic package 10 to second electronic package 10' and to electrically couple first layer of circuitry 20 to third layer of circuitry 27'. Multi-electronic device package 10 further includes bond wires 102a, 102b, 102c, and 102d made of electrically conductive material, such as gold or copper. Bond wires 102a, 102b are coupled between contacts 38a, 38b of first electronic device 36 and first layer of circuitry 20 to electrically couple first electronic device 36 to first layer of circuitry 20. Bond wires 102c, 102d are coupled between contacts 38a, 38b of second electronic device 40 and second layer of circuitry 27 to electrically couple second electronic device 40 to the second layer of circuitry 27. Bond wires 102a, 102b, 102c, 102d may be coupled to contacts 38a, 38b, 38c, 39d and first and second layers of circuitry 20, 27 using known wire bonding techniques. Multi-electronic device package 10 further includes a first encapsulant 104 preferably made of epoxy resin for covering electronic device 36, bond wires 102a, 102b and a portion of first layer of circuitry 20 and a second encapsulant 106 preferably made of an epoxy resin for covering second electronic device 40, bond wires 102c, 102d, and a portion of second layer of circuitry 27. First encapsulant 104 may be bound to an encapsulant associated with second electronic package 10' to physically couple first electronic package 10 to second electronic package 10'. Although not shown, it will be appreciated that first and second encapsulant 104, 106 may take the form of a single integral encapsulant which wraps around first electronic package 10.

Referring now to FIGS. 3 and 4, a second alternative embodiment of a multi-electronic device package 300 according to the present invention is shown. Multi-electronic device package 300 includes a first substrate 312 having a first surface 314 and opposed second surface 316. First surface 314 includes a first cavity 318 extending from first surface 314 partially into first substrate 312. A first layer of electrically conductive circuitry 320 is formed on first surface 314 of first substrate 312. A second layer of electrically conductive circuitry 322 is formed on second surface 316 of first substrate 312, wherein second layer of circuitry 322 is electrically coupled to first layer of circuitry 320 via one or more plated through holes 324a, 324b. Second layer of circuitry 322 is adapted for electrical coupling to a third external circuitized substrate (not shown). A first electronic device 326 is secured to first substrate 312 such that first electronic device 326 is positioned within first cavity 318. First electronic device 326 is electrically coupled to first layer of circuitry 320 via contacts 327a, 327b. Multi-electronic device package 300 further includes a second subsume 328 having a first surface 330 and opposed second surface 332. As in multi-electronic device package 10 of FIGS. 1 and 2, first and second substrates 312, 328 are preferably pre-peg comprising epoxy resin impregnated with glass fabric. A third layer of electrically conductive circuitry 334 is formed on second surface 332 of second substrate 328. A second electronic device 336 having contacts 327c, 327d is coupled to second substrate 328. Second electronic device 336 is electrically coupled to third layer of electrically conductive circuitry 334. First and second substrate 312, 328 are bonded together along a common interface such that the second electronic device 336 and the second surface 332 of second substrate 328 face first electronic device 326 and first surface 314 of first substrate 312, and wherein first layer of circuitry 320 is electrically coupled to third layer of circuitry 334. Plated through holes 324a, 324b extend through first substrate 312 and electrically couple first and second layers of circuitry 320, 322. Second layer of circuitry 322 includes a plurality of solder ball pads 338, 340, 342, 344, 346, 348, and 350.

Multi-electronic device package 300 further comprises solder balls 352, 354, 356, 358, 360, 362, 364 coupled to each solder ball pad 338, 340, 342, 344, 346, 348, 350, respectively, for electrically coupling second layer of circuitry 322 to the third external circuitized substrate (not shown). First layer of circuitry 320 includes a plurality of solder ball pads 366, 368, 370, 372, 374, 376. Third layer of circuitry 334 includes corresponding solder ball pads 378, 380, 382, 384, 386, 388 for each solder ball pad 366, 368, 370, 372, 374, 376 of first layer of circuitry 320. Solder balls 390, 392, 394, 396, 398, and 400 are coupled to each solder ball pad 366, 368, 370, 372, 374, and 376 and corresponding solder ball pad 378, 380, 382, 384, 386, and 388, respectively, to attach first substrate 312 to second substrate 328 along a common interface and to electrically couple first layer of circuitry 320 to third layer of circuitry 334. Bond wires 402a, 402b are wire bonded between contacts 327a, 327b of first electronic device 326 and first layer of circuitry 320. Bond wires 402c, 402d are wire bonded between contacts 327c, 327d of second electronic device 336 and third layer of circuitry 334. In this manner, first electronic device 326 is electrically coupled to first layer of circuitry 320, and second electronic device 336 is electrically coupled to third layer of circuitry 334. Multi-electronic device package 300 further includes a first encapsulant 404, preferably made of epoxy resin, covering first electronic device 326, first cavity 318, bond wires 402a, 402b, and at least a portion of first circuitry 320, and a second encapsulant 406, preferably made from epoxy resin, covering second electronic device 336, bond wires 402c, 402d, and at least a portion of the third layer of circuitry 334. First encapsulant 404 is bonded to second encapsulant 406 to attach first substrate 312 to second substrate 328. Second substrate 328 further includes an opening 408 and a thermally conductive plane 410 coupled to first surface 330 of second substrate 328 and covering opening 408. Second electronic device 336 is attached to thermally conductive plane 410 within opening 408. In this manner, second electronic device 336 is coupled to second substrate 328 via plane 410. Plane 410 dissipates heat generated from first and second electronic devices 326, 336. Additionally, substrates 312, 328 may further include embedded thermally and/or electrically conductive plans.

Referring now to FIGS. 5 and 6, a second alternative embodiment of a multi-electronic device package 500 according to the present invention is shown. Multi-electronic device package 500 comprises a first substrate 512 having a first surface 514 and an opposed second surface 516. A first layer of electrically conductive circuitry 518 is formed on first surface 514 of first substrate 512. A second layer of electrically conductive circuitry 520 is formed on second surface 516 of first substrate 512, wherein second layer of circuitry 520 is electrically coupled to first layer of circuitry 518, and wherein second layer of circuitry 520 is adapted for electrical coupling to a third external circuitized substrate (not shown). A first electronic device 522 having contacts 523a, 523b is secured to first substrate 512 and electrically coupled to first layer of circuitry 518. A second substrate 524 having a first surface 526 and a second surface 528 is also included. A third layer of electrically conductive circuitry 530 is formed on first surface 526 of second substrate 524. The second electronic device 532 having contacts 523c, 523d is coupled to second substrate 524 and is electrically coupled to third layer of circuitry 530. A fourth layer of electrically conductive circuitry 534 is formed on second surface 528 of second substrate 524, wherein fourth layer of circuitry 534 is electrically coupled to third layer of circuitry 530. Multi-electronic device package 500 includes a first encapsulant 536, preferably made from epoxy resin, covering first electronic device 522 and a portion of first layer of circuitry 518. Second substrate 524 includes a cavity 538 extending from second surface 528 of second substrate 524 partially into second substrate 524. First and second substrates 512, 524 are bonded together along a common interface such that second surface 528 of second substrate 524 faces first surface 514 of first substrate 512. At least a portion of first encapsulant 536 extends into cavity 538 to thereby decrease the distance between second surface 528 of second substrate 524 and first surface 514 of first substrate 512.

Multi-electronic device package 500 further comprises at least one plated through hole 540a, 540b, 540c extending through first substrate 512 for electrically coupling first and second layers of circuitry 518, 520. Additionally, electronic device package 50 further comprises at least one plated through hole 542a, 542b extending through second substrate 524 for electrically coupling third and fourth layers of circuitry 530, 534. Second layer of circuitry 520 includes a plurality of solder ball pads 544, 546, 548, 550, 552, 554, 556. Solder balls 558, 560, 562, 564, 566, 568, 570 are coupled to each solder ball pad 544, 546, 548, 550, 552, 554, 556, respectively, for electrically coupling second layer of circuitry 520 to the third external circuitized substrate and for physically attaching multi-electronic device package 500 to the third external circuitized substrate. The first layer of circuitry 518 includes a plurality of solder ball pads 572, 574, 576, 578, 580, 582. Fourth layer of circuitry 534 includes a corresponding solder ball pad 584, 586, 588, 590, 600, 602 for each solder ball pad 572, 574, 576, 578, 580, 582 of first layer of circuitry 518. Solder balls 604, 606, 608, 610, 612, and 614 are coupled to each solder ball pad 572, 574, 576, 578, 580, 582 and corresponding solder ball pad 584, 586, 588, 590, 600, 602 to attach first substrate 512 to second substrate 524 along a common interface and to electrically couple first layer of circuitry 518 to fourth layer of circuitry 534.

First encapsulant 536 is bonded to second substrate 524 and specifically to cavity 538 such as at 700. Although not shown, first and second substrates 512, 524 include thermally conductive and electrically conductive planes encapsulated therein. These planes dissipate heat produced by first electronic device 522 and second electronic device 532. Bond wires 616a, 616b are wire bonded between contacts 523a, 523b of first electronic device 522 and first layer of circuitry 518 to electrically couple first electronic device 522 to first layer of circuitry 518. Also, bond wires 616c, 616d are wire bonded between contacts 523c, 523d of second electronic device 532 and third layer of circuitry 530 to electrically couple second electronic device 532 to first layer of circuitry 530. First encapsulant 536 additionally coves bond wires 616a, 616b connected between first electronic device 522 and first layer of circuitry 518. A second encapsulant 618, made from epoxy resin, covers second electronic device 532, at least a portion of third layer of circuitry 530, and those bond wires 616c, 616d electrically coupling second electronic device 532 to third layer of circuitry 530. Additionally, substrates 512, 524 may further include embedded thermally and electrically conductive planes 724.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit or scope of the invention as defined in the appended claims.