This application is directed, in general, integrated circuits and, more specifically, to three-dimensional integrated circuit packages.
The electronics revolution has been fueled by transitory scaling as the technology migrated from tens of micron dimensions to sub-tenths of micron dimensions and is aimed at sub-hundredths of micron dimensions. Although digital logic continues to benefit from technology scaling, other circuit blocks such as analog, memory, and input/output (i/o) blocks may not scale down as well or as fast. Furthermore, the physical limitations of atoms and the wavelength of light are beginning to be impinged upon. Thus the cost/performance curve that has been the basis of Moore's law is beginning to stall. Alternative procedures may facilitate continuation of this cost/performance curve.
To address the deficiencies of the prior art, the present disclosure provides, in one embodiment, an electronics package. The package comprises a substrate having a planar surface, a memory die and a logic die. The memory die has memory circuit components, the memory circuit components interconnected to memory die contacts located on an outer surface of a face of the memory die. The logic die has logic circuit components, the logic circuit components interconnected to logic die contacts located on an outer surface of a face of the logic die. The memory die contacts and the logic die contacts are interconnected such that the face of the memory die opposes the face of the logic die. The electronics package also comprises a plurality of bonds that interconnect input-output contacts on the planar surface of the substrate, to external die contacts on one of the face of the logic die or the face of the memory die. The one face of the logic or memory die opposes the planar surface and the other of the logic die face or said memory die face is not directly connected to the interconnect input-output contacts.
Another embodiment is a method of manufacturing an electronics package. The method comprises providing a memory die, and providing a logic die. The memory die has memory circuit components, the memory circuit components interconnected to memory die contacts located on an outer surface of a face of the memory die. The logic die has logic circuit components, the logic circuit components interconnected to logic die contacts located on an outer surface of a face of the logic die. The method also comprises interconnecting the memory die contacts and the logic die contacts such that the face of the memory die opposes the face of the logic die. The method further comprises interconnecting input-output contacts on a planar surface of a substrate to external die contacts on one of the face of the logic die or the face of the memory die, wherein the one face of the logic or memory die opposes the planar surface and the other of the logic die face or the memory die face is not directly connected to the interconnect input-output contacts.
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Embodiments of the present disclosure replace traditional two-dimensional horizontally interconnected logic and memory dies in favor of a three-dimensional vertically interconnected configuration. In particular, electronic packages of the present disclosure benefit from the use of three-dimensional stacked die configurations with an active face-to-active face vertical interconnection between memory and logic dies, in combination with one of the die faces having direct straight-line bonds to i/o contacts on the surface of the substrate opposing that face. This combination can provide a high density of short high-speed interconnections between dies and between the vertical stack of dies and the substrate.
Such package configurations are in contrast to electronic package configurations where logic and memory dies are configured side-by-side, where vertically stacked dies are connected back to front, or, where dies are connected face-to-face but then a back end of one die is used for connection to a substrate. All of these configurations are rejected because they have longer-than-desired interconnections between the logic and memory dies or between the dies and the substrate.
As part of the present disclosure, it was recognized that to provide a high density interconnections without sacrificing interconnection speed, it is very important to minimize the length of the bond interconnecting the i/o contacts on the substrate and the contacts on the face of the one die that is interconnected to the substrate. In particular, the length of the bond between the substrate and the die face was recognized, as part of the present disclosure, as a new result-effective variable that controls the speed and density of communications between the vertically stacked dies the substrate.
One embodiment of the disclosure is an electronics package.
With continuing reference to
The faces 118, 128 of the memory and logic dies 110, 120 can be referred to as active (e.g., active face 118 or active face 128) because the circuit components 112, 122 are routed to their respective surfaces 116, 126.
Additionally, the package 100 comprises a plurality of bonds 130 that interconnect input-output contacts 132, located on the planar surface 107 of the substrate 105, to external die contacts 135 located on one of the face 128 of logic die 120, or, the face 118 of the memory die 110, such that the one face 118 or face 128 (e.g., face 128 in the examples shown in
As further illustrated in
For the particular configuration depicted in
As further illustrated in
In still other embodiments, such as when the positions of the memory die 110 and logic die 120 are reversed, e.g., as compared to that depicted in
As illustrated in the detailed cross-sectional view presented in
When the dies 110, 120 are interconnected to form a vertical stack 153, the micro-bond's diameters 152 are equal to the gap distance 154 between the face 118 of the memory die 110 and the face 128 of the logic die 120. It is preferable to interconnect the dies 110, 120 using micro-bonds 150 because these short-length bonds allow configurations with a high number of interconnects per unit area (e.g., a high interconnect density). Smaller diameter 152 micro-bonds 150 are also preferred because the resulting smaller gap 154 between the memory die face 118 and logic die face 128, facilitates a faster communication of information between the memory die 110 and logic die 120, because the distance for an electrical signal to travel between the dies 110, 120 is shorter.
As illustrated in the detailed plan view presented in
The size of the micro-bond 150 interconnecting pairs of die contacts 118, 128, which is equal to the diameter 152, is an important variable which controls the maximum density interconnections that are possible between the dies 110, 120 as well as the speed of communication between individual pairs of contacts 118, 128. For example, if the desired number of interconnections per square millimeter equals about 400, then the desired pitch 157 equals about 50 microns, and therefore the desired micro-bond diameter 152 equals about 25 microns or less. For example, if the desired number of interconnections per square millimeter equals about 1000, then the desired pitch 157 equals about 30 microns, and therefore the desired micro-bond diameter 152 equals about 15 microns or less.
Similarly, the size of the bond 130 interconnecting the i/o contacts 132 and external die contacts 135 can be an important variable controlling the maximum density of interconnections that are possible between the vertical stack of dies 153 and substrate 105 as well as the speed of communication between individual pairs of contacts 132, 135. As further illustrated in
For example, in some embodiments, bonds 130 interconnecting the input-output contacts 132 and external die contacts 135 can be laid out in an array 167 (e.g., 1-dimensional or 2-dimensional array) having a pitch 165 between adjacent bonds 130 of about 200 microns or less. In such cases, the diameter 160 of the bonds 130 is preferably about 100 microns or less, which in turn, is equal to the gap 162 between the input-output contacts 132 and external contacts 135. For instance, in embodiments where the pitch 165 equals about 50 microns, the number of interconnections per square millimeter equals about 400, and at a pitch 165 of about 30 microns, the interconnections per square millimeter equals about 1000. The diameter 160 refers to a deformed bond 160 after the one die (e.g., one of the dies 110, 120) are interconnected to the input-output contacts 132 (e.g., a distance after a reflow or compression process to form the bond 160).
In some configurations of the package 100, the presence of the other die that is located between the die that is interconnected to the substrate, can interfere with the goals of having a high density of interconnections and/or short interconnection lengths. For instance, for the package 100 configuration depicted in
Accordingly, in some embodiments, it can be advantageous to reduce the memory die's thickness 170 because this helps to minimize the gap 162 that the bonds 130 have to bridge. For instance, in some embodiments, the memory die's thickness 170 can equal about 50 microns or less, and more preferably about 10 microns. In other package configurations, where the positions of the memory die 110 and logic die 120 are reversed (not shown), the thickness of the logic die could have a similar reduced thickness.
In still other embodiments, the location of one of the dies in a substrate cavity can help to minimize the distance separating the contacts on the substrate and die. An example of such an embodiment in illustrated in
As shown in
In some cases, achieving the desired density of i/o contacts 132 on the package substrate 105 may be difficult to achieve, e.g., because of the thickness of one of the dies (e.g., the the thickness 170 of the memory die 110 in
An example of such an embodiment is illustrated in
The use of an interposer body 305 of the present disclosure is in contrast to electronic packages where logic and memory dies are interconnected in a horizontally configuration on an interposer, or, where dies are vertically interconnected through an interposer that is located in between the dies. A problem with such package configurations is that they can introduce timing delays between die-to-die contacts or die-to-i/o contacts due to the presence of long horizontal or vertical routing traces in or on the interposer body.
In some embodiments, the through-body-vias 310 have a diameter 330 of about 50 microns or less, which in turn, can provide a pitch 335 of through-body-vias 310 of about 100 microns or less. In some cases, the diameter 330 is in a range of about 40 to 5 microns, providing a corresponding pitch 335 in a range of about 80 microns to 10 microns, respectively. In some cases, a density of the through-body-vias 310 corresponds to at least about 300 per square millimeter of the sides 317, 322 of the interposer body 310.
As further illustrated in
Embodiments of the package, such as the example packages depicted in
Another embodiment is a method of manufacturing an electronics package.
With continuing reference to
In some embodiments of the method 400, providing the memory die in step 405 includes a step 422 of forming the memory die 110, which in turn, can include a step 425 of forming the memory circuit components 112 on or in the face 118 of the memory die 110. Similarly, providing the logic die (step 410), can include a step 430 of forming the logic die 120, which in turn, can include a step 432 of forming the logic circuit components 122 on or in the face 128 of the logic die 120.
One skilled in the art would be familiar with the standard procedures in the semiconductor industry, which can be used as part of steps 422-432, in the manufacture of memory circuit and logic circuits in or on the dies, the formation of interlayer metal and dielectric layers, and, the formation of surface contacts on the dies (e.g., memory die contacts 114, logic die contacts 124, and external die contacts 135) to facilitate interconnection with other components outside of the die. The contacts 114, 124 can be formed so as to have the desired pitch (e.g., equal to the pitch 157 between micro-bonds 150) to facilitate forming the desired number of die-to-die interconnections per square millimeter, such as previously discussed in the context of
In some embodiments of the method 400, interconnecting the memory die contacts 114 and the logic die contacts 124 in step 415 can include a step 435 of forming micro-bonds 150 between the contacts 114, 124. The micro-bonds 150 can be formed to have the desired diameter 152 and pitch 155 to facilitate forming the desired number of die-to-die interconnections per square millimeter, such as previously discussed in the context of
In some cases, flip-chip bonding can be used to form the micro-bonds 150 as part of step 435. One skilled in the art would be familiar with the procedures, as part of step 435, to perform flip-chip bonding, including forming alignment structures on the faces 118, 128 of memory and logic dies 110, 120, to facilitate the proper alignment of the memory die contacts 114 with the logic die contacts 124. One skilled in the art would be familiar with procedures, also as part of step 415, to use micro-manipulators to flip one die onto the other die, and, to form the micro-bonds 150, e.g., by solder ball bonding, compression bonding, reflow bonding or thermocompression bonding.
In some embodiments of the method 400, interconnecting the input-output contacts 132 to the external die contacts 135 in step 420 can include forming bonds 130 between the contacts 132, 135. For instance, flip-chip bonding, similar to that described in the context of step 415, can be used as part of step 420 to form the bonds 130, e.g., such that solder balls, compression bonds, reflow bond or thermocompression bonds directly touch the contacts 132, 135.
Some embodiments of the method 400 further include a step 440 of filling a gap 154 between the memory die 110 and the logic die 120 with a dielectric material 137. In some preferred embodiments step 440 is conducted after the dies 110, 120 are interconnected in step 415. For instance, as part of step 440, a sufficient amount of dielectric material 137 such as an epoxy polymer, in liquid form, can be introduced into the gap 154 and then cured to form a solid polymer such that the memory die 110 and logic die 120 are at least in part held together by the dielectric material 137. In different embodiments, the dielectric material 137 can partially fill, or, entirely fill the gap 154.
Some embodiments of the method 400 further include a step 445 of forming a cavity 210 in the substrate 105. For instance, a portion of the substrate 105 at the planar surface 107 of the substrate 105 can be micromachined to form the cavity 210. Or in other embodiments, the cavity 210 could be formed in step 445 using wet chemical etching, plasma etching, or reactive ion etching processes to remove a portion of the substrate 105, such as a semiconductor substrate (e.g., a silicon substrate). In still other embodiments, such as when the substrate 105 includes a multilayered package substrate, portions of different layers 215, 220 (e.g., a solder mask layer 215 and metal layer 220 in the embodiment shown in
In cases whether there is a cavity 210 is formed in the substrate 105, the interconnecting step 420 can further include a step 450 of locating the other one of the memory die 110 or the logic die 120 (e.g., the memory die 110 for the embodiment shown in
Some embodiments of the method 400 further include a step 460 of providing an interposer body 305. As previously discussed in the context of
Some embodiments of the method 400 further include a step 470 of forming a cavity 340 in the interposer body 305 provided in step 440. The interposer cavity 340 can be formed by the same types of processes described for the formation of the substrate cavity 210 in step 445. In such embodiment, where a cavity 340 is formed in the interposer body 305, the step 420 of interconnecting the i/o contacts 132 and external die contacts 135 can include the step 450 of locating the other one of the memory die 110 or the logic die 120 that is not directly interconnected to the input-output contacts 132 (e.g., the memory die 110 shown in
In some embodiments, providing the interposer body 305 in step 465 further includes a step 475 includes etching a semiconductor layer 360 (e.g., a silicon layer) to form openings 365 through the semiconductor layer 360 for the through-body-vias 310. In preferred embodiments, where it is desirable to have a high density of interconnections to one of the dies 110, 120, the via openings 365 have a diameter 330 of 50 microns or less and a pitch 335 of about 100 microns or less. The via openings 365 can be filled with a metal (e.g., copper) in a step 477 using conventional chemical physical or vapor deposition or electrochemical deposition procedures.
Those skilled in the art to which this application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments.
This application claims the benefit of U.S. Provisional Application Ser. No. 61/211,004, filed by Burleson et al. on Mar. 25, 2009, entitled, “Micromachined Si interposer for 3D packaging,” commonly assigned with this application, and incorporated in its entirety herein.
Number | Date | Country | |
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61211004 | Mar 2009 | US |