The present invention relates to a module and a method for manufacturing such a module.
Conventionally, a volatile memory (RAM) such as a dynamic random access memory (DRAM) has been known as a storage device. The DRAM is required to have a large capacity such that it can support high performance of an arithmetic unit (hereinafter referred to as a logic chip) and an increase in an amount of data. For this reason, attempts have been made to increase the capacity by way of miniaturization of the memory (memory cell array, memory chip) and planar addition of cells. On the other hand, this type of increase in capacity is reaching its limit because of the miniaturization resulting in feebleness to noise, an increase in chip area, and other factors.
Therefore, in recent years, a technique for achieving a large capacity by way of a three-dimensional (3D) structure that is formed by stacking a plurality of planar memories has been developed. In addition, as the amount of data increases, the speed of data communication between chips (a logic chip and a memory chip) has been increased (for example, see Patent Documents 1 and 2).
Patent Document 1 discloses a semiconductor module having a configuration in which bridge connection is established between two chips. The semiconductor module of Patent Document 1 includes an additional chip such as a stacked memory connected via an additional wiring structure. The entirety of the semiconductor module of Patent Document 1 is sealed with a molding material while forming a build-up wiring layer, and has bumps on its surface which are for connection to a package substrate.
Patent Document 2 discloses a semiconductor module having a configuration in which a logic chip and a memory chip are arranged on a carrier substrate and sealed with a molding material. According to Patent Document 2, a redistribution layer and a through via are formed on the molding material. The semiconductor module of Patent Document 2 includes an interposer disposed so as to straddle the logic chip and the memory chip. Furthermore, a further redistribution layer and bumps are sequentially formed on the interposer of the semiconductor module of Patent Document 2.
The semiconductor module of Patent Document 1 tends to increase in cost due to an I/O connection structure for the bridge connection and the build-up wiring for connection to the bumps. The semiconductor module of Patent Document 2 also tends to increase in cost because it requires formation of the further redistribution layer and the through via, resulting in an increase in the number of process steps. It is favorable to reduce the cost for manufacturing a module including a plurality of chips.
The present invention has been achieved in view of the disadvantages described above, and it is an object of the present invention to provide a module including a plurality of chips and manufactured at a reduced cost and a method for manufacturing such a module.
The present invention relates to method for manufacturing a module including a predetermined number of stacked memories. The method includes: a stacked wafer forming step of forming a stacked wafer by stacking a plurality of memory wafers in a bump-less manner; a dicing step of dicing the stacked wafer into the stacked memories as individual pieces; a rearrangement step of rearranging a plurality of the stacked memories in a predetermined shape; a molding step of molding the stacked memories that have been rearranged; a wiring forming step of forming external wiring on the stacked memories; and a separation step of separating a resultant semifinished product into memory modules each including a predetermined number of the stacked memories that have been molded.
Preferably, the method for manufacturing the module further includes, after the rearrangement step and before the molding step, an external through electrode forming step of forming an external through electrode that extends in a stacking direction of the stacked memories. It is preferable that in the rearrangement step, the stacked memories as the individual pieces are disposed on each other and rearranged in a predetermined shape, and in the molding step, the stacked memories that have been rearranged and the external through electrode are molded.
It is preferable that in the rearrangement step, the stacked memories and a logic chip are rearranged in a predetermined shape, and in the molding step, the stacked memories and the logic chip are molded.
It is preferable that in the rearrangement step, the logic chip is stacked on the plurality of stacked memories.
It is preferable that in the rearrangement step, the logic chip is stacked on the plurality of stacked memories so as to straddle the plurality of stacked memories.
It is preferable that in the rearrangement step, the stacked memories are stacked on the logic chip.
The present invention relates to a method for manufacturing a module including a predetermined number of stacked memories. The method including: a stacked wafer forming step of forming a stacked wafer by stacking a plurality of memory wafers in a bump-less manner; a rearrangement step of stacking a logic chip such that the logic chip straddles a plurality of stacked memories included in the stacked wafer; and a separation step of separating the stacked wafer having the logic chip stacked thereon into memory modules each including a predetermined number of the stacked memories.
It is preferable that in the rearrangement step, the logic chip is stacked on a control chip that is exposed on one surface of the stacked wafer in a stacking direction and that controls the operation of the stacked memories.
The present invention relates to a module provided with a predetermined number of stacked memories. The module including: the predetermined number of stacked memories each including memory chips stacked by bump-less connection; a packaging part that packages the predetermined number of stacked memories; and an external wiring disposed on one surface of the stacked memories in a stacking direction.
Preferably, the module further includes a logic chip stacked on the stacked memories, and the packaging part packages the logic chip and the stacked memories.
Preferably, the module further includes a logic chip juxtaposed to the stacked memories in a direction intersecting with a stacking direction of the stacked memories, and the packaging part packages the logic chip and the predetermined number of memories.
Preferably, the module further includes an external through electrode that extends in a stacking direction of the stacked memories. It is preferable that a plurality of the stacked memories are stacked in the stacking direction, the packaging part further packages the external through electrode, and the external wiring is disposed on one surface of the stacked memory, the one surface being exposed from the packaging part.
The present invention relates to a module provided with a plurality of stacked memories. The module includes: the plurality of stacked memories each including memory chips stacked by bump-less connection; and a logic chip stacked on the stacked memories that are juxtaposed to each other in a direction intersecting with a stacking direction of the stacked memories in such a manner that the logic chip straddles the stacked memories.
It is preferable that each stacked memory comprises the memory chips, and a control chip that is exposed on one surface in a stacking direction and controls operation of the memory chips.
The present invention provides a module including a plurality of chips and manufactured at a reduced cost, and a method for manufacturing such a module.
In the following, a module 1 according to each embodiment of the present invention and a manufacturing method thereof will be described with reference to
The module 1 according to each embodiment is manufactured using the fan out wafer level package (FOWLP) technology, without a Si interposer or a Si bridge. Thus, the module 1, which does not have to include a package substrate or the like, can be manufactured inexpensively. The module 1 of each embodiment is a multichip module (MCM) 1 including a plurality of stacked memories 11 or a logic chip 20. In particular, the module 1 of each embodiment is produced by modularizing memory chips 110, which are individual pieces obtained by dicing a stacked memory including wafers stacked in a bump-less manner, using the FOWLP technology. As a result, a thin MCM with a low height can be manufactured.
Next, the module 1 according to a first embodiment of the present invention and a manufacturing method thereof will be described with reference to
Each stacked memory 11 includes memory chips 110 stacked together by bump-less connection. Each stacked memory 11 is formed by stacking, by bump-less connection, the memory chips 110 each having an Si layer 112 constituting one surface thereof and a wiring layer 111 constituting the other surface thereof, for example. Specifically, a pair of memory chips 110 are connected to each other by bump-less connection with their wiring layers facing each other, and two or more pairs of memory chips 110 are stacked on each other by bump-less connection, whereby the stacked memory 11 is formed. In the present embodiment, each stacked memory 11 includes four memory chips 110 stacked together. The memory chips 110 stacked to form each stacked memory 11 have a rectangular shape of the same size when viewed in plan view along the stacking direction d.
Each internal through electrode 12 is an electrode penetrating the stacked memory 11. For example, each internal through electrode 12 penetrates the stacked memory chips 110 in the stacking direction d, from one surface of the stacked memory 11. In the present embodiment, each internal through electrode 12 penetrates the wiring layers 111 of all the memory chips 110 included in one stacked memory 11 from one surface of the one stacked memory 11. Four internal through electrodes 12 are arranged in the cross section taken along the line A-A in
The internal redistribution layer 13 is stacked on one surface of one set of the stacked memories 11 in the stacking direction d. The internal redistribution layer 13 is electrically connected to the internal through electrodes 12 of an adjacent one of the stacked memories 11 included in the one set of stacked memories 11. When viewed in plan view, the internal redistribution layer 13 has a rectangular shape of larger dimensions than the rectangular stacked memory 11. In other words, the internal redistribution layer 13 is disposed with its side edges protruding with respect to the edges of the stacked memory 11 in the direction intersecting with the stacking direction d.
The external through electrodes 14 extend in the stacking direction d of the stacked memories 11. Each external through electrode 14 is, for example, a Cu pillar. One end of each external through electrode 14 is electrically connected to the internal redistribution layer 13. In the present embodiment, a pair of the external through electrodes 14 are arranged while sandwiching the stacked memories 11 therebetween in the cross section taken along the line A-A.
The packaging part 15 packages a predetermined number of stacked memories 11. The packaging part 15 is formed of, for example, a molding material such as resin. For example, as illustrated in
The external wiring 16 is disposed on one surface of the assemblage of the stacked memories 11 in the stacking direction d. Specifically, the external wiring 16 is disposed on the one surface of the assemblage of the stacked memories 11 that is exposed from the packaging part 15. The external wiring 16 includes an external redistribution layer 161 and solder balls 162.
The external redistribution layer 161 is provided on the one surface of the assemblage of the stacked memories 11 that is exposed from the packaging part 15. The external wiring 16 has a rectangular shape of the same dimensions as those of the internal redistribution layer 13 when viewed in plan view. The external redistribution layer 161 is electrically connected to the internal through electrodes 12 of an adjacent one of the stacked memories 11 included in one set of stacked memories 11. The external redistribution layer 161 is electrically connected to the other end of each external through electrode 14.
The solder balls 162 are arranged on an exposed surface of the external redistribution layer 161. The solder balls 162 are electrically connected to the external redistribution layer 161. In this embodiment, the plural solder balls 162 are arranged along the exposed surface of the external redistribution layer 161.
Next, an operation of the module 1 will be described. The module 1 is electrically connected to another substrate or the like via the solder balls 162. The stacked memories 11 adjacent to the external redistribution layer in the stacking direction d are capable of transmitting and receiving data via the internal through electrodes 12, the external redistribution layer 161, and the solder balls 162. The stacked memories 11 adjacent to the internal redistribution layer 13 in the stacking direction d are capable of transmitting and receiving data via the internal through electrodes 12, the internal redistribution layer 13, the external through electrodes 14, the external redistribution layer 161, and the solder balls 162.
Next, a method for manufacturing the module 1 will be described. The method is for manufacturing the module 1 including a predetermined number of stacked memories 11. The method for manufacturing the module 1 includes a stacked wafer forming step, a dicing step, a rearrangement step, an external through electrode forming step, a molding step, an internal redistribution layer forming step, a wiring forming step, and a separation step.
First, the stacked wafer forming step is performed to form a stacked wafer including a plurality of memory wafers 100 stacked in a bump-less manner. In the stacked wafer forming step, as illustrated in
Next, the dicing step is performed. In the dicing step, the stacked wafer is diced into the stacked memories 11 as individual pieces. As illustrated in
Next, the rearrangement step is performed. In the rearrangement step, the plurality of stacked memories 11 are rearranged in a predetermined shape on a carrier substrate 200. The carrier substrate 200 is made of silicon, glass, or the like. The carrier substrate 200 typically has a circular or rectangular plate shape. Furthermore, in the rearrangement step, the stacked memories 11 as individual pieces are disposed on each other into a predetermined shape. In the rearrangement step, for example, a plurality of stacked memories 11 are stacked in the stacking direction d, thereby forming one set. A plurality of sets of stacked memories 11 are juxtaposed to each other in a direction intersecting with the stacking direction d. In the rearrangement step of the present embodiment, as illustrated in
Next, the external through electrode forming step is performed. As illustrated in
Next, the molding step is performed. In the molding step, as illustrated in
Next, the internal redistribution layer forming step is performed. In the internal redistribution layer forming step, an internal redistribution layer 13 is formed adjacent to one end of each external through electrode 14 and one surface in the stacking direction d of the stacked memory 11. In the internal redistribution layer forming step, the molding material is polished from one side in the stacking direction d, whereby the external through electrodes 14 and one surface in the stacking direction d of the stacked memories 11 are exposed. Subsequently, the internal redistribution layer 13 is formed. The internal redistribution layer 13 is then molded with a molding material.
Next, the wiring forming step is performed. In the wiring forming step, external wiring 16 is formed on the stacked memories 11. In the wiring forming step, solder balls 162 are arranged on the exposed surface of the external redistribution layer 161.
Next, the separation step is performed. In the separation step, the resultant semifinished product is separated into memory modules 1 each including a predetermined number of molded stacked memories 11. In the separation step, the resultant semifinished product is separated into pieces each including two sets of stacked memories 11, so that the modules 1 illustrated in
The above-described module 1 and manufacturing method thereof according to the first embodiment exert the following effects.
(1) A method for manufacturing the module 1 including a predetermined number of stacked memories 11 includes: a stacked wafer forming step of forming a stacked wafer by stacking a plurality of memory wafers 100 in a bump-less manner; a dicing step of dicing the stacked wafer into the stacked memories 11 as individual pieces; a rearrangement step of rearranging a plurality of stacked memories 11 in a predetermined shape; a molding step of molding the stacked memories 11 that have been rearranged; a wiring forming step of forming the external wiring 16 on the stacked memories 11; and a separation step of separating a resultant semifinished product into the memory modules 1 each including the predetermined number of molded stacked memories 11. The module 1 includes the predetermined number of stacked memories 11 each including a predetermined number of memory chips 110 stacked by bump-less connection, the packaging part 15 that packages the predetermined number of stacked memories 11, and the external wiring 16 disposed on one surface of the stacked memories 11 in the stacking direction d. As a result, the module 1 including a plurality of chips can be manufactured without using a package substrate or the like, whereby the module 1 can be manufactured inexpensively. The stacked memories 11 are modularized into the module 1 by the FOWLP technology. As a result, a thin MCM with a low height can be manufactured. At this time, since each stacked memory 11 is formed by stacking the memory chips in a bump-less manner, the thickness of the stacked memory 11 in the stacking direction d is as small as about ½ to ⅙ of the thickness of a typical stacked memory including pumps in a case where the stacked memory 11 and the typical stacked memory have the same number of layers of memory chips. Thus, a thin MCM including a large number of memory chips 110 and having a low height can be manufactured. Furthermore, it is possible to obtain a memory chip 110 whose height (thickness in the stacking direction d) is the same as the height of a memory chip included in another stacked memory 11. As a result, the heights after the rearrangement can be made uniform in a FOWLP process, whereby the yield of a step of forming a redistribution layer (RDL) and a step of arranging the solder balls 162 can be improved. Moreover, the memory chips 110 as individual pieces are stacked to be modularized into the module 1 by the FOWLP technology, whereby the small-area module 1 with a reduced footprint can be produced.
(2) The method for manufacturing the module 1 further includes: after the rearrangement step and before the molding step, and in the rearrangement step, the external through electrode forming step of forming the external through electrodes 14 that extends in the stacking direction d of the stacked memories 11. In the rearrangement step, the stacked memories 11 as individual pieces are disposed on each other and rearranged in a predetermined shape, and in the molding step, the rearranged stacked memories 11 and the external through electrodes 14 are molded. The module 1 further includes the external through electrodes 14 extending in the stacking direction d of the stacked memories 11, the plurality of stacked memories 11 are stacked in the stacking direction d, the packaging part 15 further packages the external through electrodes 14, and the external wiring 16 is disposed on one surface of the stacked memories 11 exposed from the packaging part 15. This configuration makes it possible to easily transmit power and a signal even between the stacked memories 11 disposed on each other, thereby improving the flexibility of arrangement.
Next, a module 1 according to a second embodiment of the present invention and a manufacturing method thereof will be described with reference to
The above-described module 1 and manufacturing method thereof according to the second embodiment exert the following effects.
(3) In the rearrangement step, the stacked memories 11 and the logic chip 20 are rearranged in a predetermined shape, in the molding step, the stacked memories 11 and the logic chip 20 are molded, and in the separation step, the resultant semifinished product is separated into memory modules 1 each including a predetermined number of the stacked memories 11 and the logic chip 20. The module 1 further includes the logic chip 20 juxtaposed in a direction intersecting with the stacking direction d of the stacked memories 11, and the packaging part 15 packages the logic chip 20 and the predetermined number of the memories. Thus, the manufacturing cost of the module 1 including the logic chip 20 can also be reduced.
Next, a module 1 according to a third embodiment of the present invention will be described with reference to
An external redistribution layer 161 is formed on one surface of the logic chip 20. The stacked memories 11 are arranged over the other surface of the logic chip 20. An internal redistribution layer 13 and an external redistribution layer 161 each have a rectangular shape in plan view, which is larger than the size the outer shape of the rectangular logic chip 20.
The above-described module 1 and manufacturing method thereof according to the third embodiment exert the following effects.
(4) In the rearrangement step, the logic chip 20 is stacked to the plurality of stacked memories 11. The module 1 further includes the logic chip 20 stacked to the stacked memories 11, and the packaging part 15 packages the logic chip 20 and the stacked memories 11. Due to this configuration, the module 1 can have a reduced size in plan view in comparison with a case where a logic chip 20 is juxtaposed to the stacked memories 11 in a direction intersecting with the stacking direction d of the stacked memories 11.
Next, a module 1 according to a fourth embodiment of the present invention will be described with reference to
The above-described module 1 and manufacturing method thereof according to the fourth embodiment make it possible to reduce the height at which the internal redistribution layer 13 is positioned and shorten the length of the external through electrodes 14, thereby facilitating the manufacture of the module 1.
Next, a module 1 according to a fifth embodiment of the present invention and a manufacturing method thereof will be described with reference to
The above-described module 1 and manufacturing method thereof according to the fifth embodiment make it possible to produce a module 1 having a lager capacity.
Next, a module 1 according to a sixth embodiment of the present invention and a manufacturing method thereof will be described with reference to
The above-described module 1 and manufacturing method thereof according to the sixth embodiment makes it easier to manufacture the modules 1 having a large capacity by repeating the steps.
Next, a module 1 according to a seventh embodiment of the present invention and a manufacturing method thereof will be described with reference to
The above-described module 1 and manufacturing method thereof according to the seventh embodiment make it easy to manufacture the module 1 having a larger capacity. Furthermore, the seventh embodiment makes it possible to reduce the manufacturing cost of the module 1.
Next, a module 1 according to an eighth embodiment of the present invention and a manufacturing method thereof will be described with reference to
Each control chip 30 is disposed adjacent to the internal redistribution layer 13 in the stacking direction d of the stacked memories 11. Each control chip 30 includes, for example, a memory controller, a memory interface, an arbiter circuit, a router, a switch, etc. In the eighth embodiment, the bidirectional arrows crossing the connection surface between the control chip 30 and the logic chip 20 indicate communication paths between the control chip 30 and the logic chip 20, and a non-contact communication means such as magnetic field communication or capacitive coupling communication may be used as a communication method. Alternatively, hybrid connection or connection using micro bumps may be used. In this case, the internal redistribution layer 13 do not have to be provided. On a lower surface of the packaging part 15 that covers a surface of the stacked memory 11 (chip) opposite in the stacking direction d to a surface on which the control chip 30 is disposed, external wiring 16 (not shown) including an external redistribution layer 161 and solder balls 162 may be provided.
The above-described module 1 and manufacturing method thereof according to the eighth embodiment make it possible to stack the logic chips 20 on the stacked memories 11 after rearrangement of selecting non-defective stacked memories 11, thereby enabling improvement of the yield. Furthermore, since the separated pieces can include an arbitrary number of logic chips 20, MCMs can be manufactured in a scalable manner.
Next, a module 1 and a manufacturing method thereof according to a ninth embodiment of the present invention will be described with reference to
The above-described module 1 and manufacturing method thereof according to the ninth embodiment exert the following effects.
(5) The module 1 includes a plurality of stacked memories 11 each including memory chips 110 stacked by bump-less connection, and the logic chip 20 disposed on the stacked memories 11 juxtaposed to each other in a direction intersecting with the stacking direction d such that the logic chip 20 straddles the stacked memories 11. The method for manufacturing the module 1 including a predetermined number of stacked memories 11 includes: a stacked wafer forming step of forming a stacked wafer by stacking a plurality of memory wafers 100 in a bump-less manner; a rearrangement step of arranging the logic chips 20 such that each logic chip 20 straddles a plurality of stacked memories 11 included in the stacked wafer; and a separation step of separating the stacked wafer having the logic chips 20 arranged thereon into a memory modules 1 each including the predetermined number of the stacked memories 11. Thus, the logic chips 20 are arranged on the stacked wafer including wafers stacked in a bump-less manner, or on a panel formed by rearranging individual pieces obtained by dicing the stacked wafer, and thereafter the resultant semifinished product is diced into the modules 1 as individual pieces. This feature makes it easier to align the chips as the individual pieces with each other, in comparison with a case where chips as individual pieces are arranged one-by-one and connected to each other. In addition, since the logic chips 20 are arranged on the stacked wafer including wafers stacked in a bump-less manner, or on a panel formed by rearranging individual pieces obtained by dicing the stacked wafer, the degree of freedom of arrangement of the logic chips and density of the logic chips can be increased. Furthermore, each logic chip can be arranged so as to straddle a plurality of memories, and the number of logic chips and the number of memories can be determined in a scalable manner.
In the foregoing, some preferred embodiments of the module of the present invention and the manufacturing method thereof have been described. It should be noted that the present invention is not limited to the above-described embodiments and can be appropriately modified.
For example, in the ninth embodiment, the size of the logic chip 20 can be appropriately changed as illustrated in in
In the ninth embodiment, as illustrated in
In the eighth embodiment and the ninth embodiment, after the logic chips 20 are disposed, the entirety of the resultant semifinished product may be molded and then separated into the modules 1.
According to the above-described embodiment and the second embodiment, in a case where the stacked memories 11 or the logic chip 20 are/is juxtaposed in a direction intersecting with the stacking direction d, it is not necessary to stack the stacked memories 11 or the logic chip 20. In this case, the external through electrode 14 may be omitted from the module 1.
In addition, among the internal through electrodes 12 of the stacked memory 11, one or more that transmit a signal may use a non-contact communication means such as magnetic field communication or capacitive coupling communication. The internal through electrodes 12 may have a structure in which electrodes penetrate the respective memory chips and the electrodes are hybrid-connected to each other at connection surfaces. These are examples of electrical connection means for bump-less connection.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/014944 | 4/8/2021 | WO |