PACKAGED MEMORY DEVICE WITH FLIP CHIP AND WIRE BOND DIES
20220285316 · 2022-09-08
Inventors
- Rui YUAN (Shanghai, CN)
- Hope Chiu (Shanghai City, CN)
- Paul Qu (Shanghai, CN)
- Kevin Du (Shanghai, CN)
- Zengyu Zhou (Shanghai, CN)
- Yi Su (Shanghai, CN)
- Shixing Zhu (Shanghai, CN)
Cpc classification
H01L24/95
ELECTRICITY
H01L2225/06517
ELECTRICITY
H01L25/18
ELECTRICITY
H01L25/0652
ELECTRICITY
H01L2225/06506
ELECTRICITY
H01L2225/0651
ELECTRICITY
H01L2225/06558
ELECTRICITY
H01L2225/06562
ELECTRICITY
H10B43/27
ELECTRICITY
G11C5/06
PHYSICS
H10B41/27
ELECTRICITY
H01L23/4951
ELECTRICITY
International classification
H01L25/065
ELECTRICITY
G11C5/06
PHYSICS
H01L21/50
ELECTRICITY
Abstract
A memory device includes a substrate, a controller die, a flip chip die, first and second silicon dies, and bond wires. The controller and flip chip dies are attached to the substrate using connection balls and in electrical communication with each other. The first and second silicon dies include respective first and second contact pad surfaces. The bond wires electrically connect the contact pad surfaces to the substrate so the first and second silicon dies communicate with the controller die. The flip chip die and first and second silicon dies are NAND dies, the flip chip die is configured as SLC memory, and the silicon dies are configured as one of MLC memory, TLC memory, or QLC memory.
Claims
1. A memory device comprising: a substrate; a controller die attached to the substrate; a flip chip die attached to the substrate, adjacent to the controller die, and in electrical communication with the controller by way of the substrate; a first silicon die having a bottom surface attached to one of the substrate or a top surface of the flip chip die, the first silicon die including a first contact pad surface opposite to the bottom surface; a second silicon die attached to the first contact pad surface of the first silicon die, the second silicon die including a second contact pad surface; one or more bond wires that electrically connect the first and second contact pad surfaces to the substrate, thereby electrically connecting the first and second silicon dies to the controller die by way of the substrate.
2. The memory device of claim 1, wherein the flip chip die and the first and second silicon dies comprise memory dies.
3. The memory device of claim 2, wherein the flip chip die is configured as a single-level cell (SLC) memory and the first and second silicon dies are configured as one of a multi-level cell (MLC) memory, a triple-level cell (TLC) memory, and a quad-level cell (QLC) memory.
4. The memory device of claim 1, further comprising: a first adhesive layer attaching the bottom surface of the first silicon die to the top surface of the flip chip die, wherein at least a portion of the flip chip die is disposed between the substrate and the first silicon die.
5. The memory device of claim 4, further comprising: a second adhesive layer attaching a bottom surface of the second silicon die to the first contact pad surface of the first silicon die.
6. The memory device of claim 4, wherein top surfaces of the controller die and the flip chip die are substantially planar.
7. The memory device of claim 6, wherein one portion of the bottom surface of the first silicon die is attached to the top surface of the flip chip die and another portion of the bottom surface of the first silicon die is attached to the top surface of the controller die such that both the flip chip die and the controller die support the first silicon die.
8. The memory device of claim 1, wherein the bottom surface of the first silicon die is attached to the substrate and adjacent to the flip chip die.
9. The memory device of claim 1, further comprising: a third silicon die having a bottom surface attached to the second contact pad surface of the second silicon die, the third silicon die including a third contact pad surface; and the one or more bond wires electrically connect the third contact pad surface to the substrate, thereby electrically connecting the third silicon die to the controller die by way of the substrate.
10. The memory device of claim 1, wherein the two or more silicon dies are offset from each other.
11. The memory device of claim 1, further comprising: a first plurality of solder bumps that attach the controller die to the substrate; a second plurality of solder bumps that attach the flip chip die to the substrate; and underfill disposed beneath the controller die and the flip chip die and between the first plurality of solder bumps and the second plurality of solder bumps.
12. A memory device, comprising: a substrate; a controller die attached and electrically connected to the substrate with a plurality of first solder balls; a flip chip die attached and electrically connected to the substrate, adjacent to the controller die, with a second plurality of solder balls, such that the flip chip die is in communication with the controller die by way of the substrate; and a plurality of silicon dies stacked one atop another in an offset manner, wherein a bottom one of the silicon dies is attached to one of a top surface of the flip chip die and the substrate, and wherein the plurality of silicon dies are electrically connected to the substrate with bond wires such that the plurality of silicon dies are in communication with the controller die by way of the substrate, and wherein the flip chip die and the plurality of silicon dies comprise NAND dies.
13. The memory device of claim 12, wherein the flip chip die is configured as a single level cell (SLC) memory and the plurality of silicon dies are configured as one of multi-level cell (MLC), triple-level cell (TLC), and quad-level cell (QLC) memory.
14. The memory device of claim 13, wherein the plurality of silicon dies are attached to the top surface of the flip chip die.
15. A method of assembling a memory device, the method comprising: attaching a controller die to a substrate; attaching a flip chip die to the substrate and adjacent to the controller die, wherein the flip chip die is in communication with the controller die by way of the substrate; attaching a bottom surface of a first silicon die to a top surface of the flip chip die, the first silicon die including a first contact pad surface opposite to its bottom surface; attaching a bottom surface of a second silicon die to the first contact pad surface of the first silicon die, the second silicon die including a second contact pad surface opposite its bottom surface; electrically connecting the first and second contact pad surfaces to the substrate with bond wires such that the first and second silicon dies are in communication with the controller die by way of the substrate.
16. The method of claim 15, wherein attaching the controller die to the substrate and attaching the flip chip die to the substrate are performed substantially simultaneously.
17. The method of claim 15, wherein attaching the first silicon die to the flip chip die includes placing a first adhesive layer between the first silicon die and the flip chip die.
18. The method of claim 17, wherein attaching the second silicon die to the first silicon die includes placing a second adhesive layer between the second silicon die and the first silicon die and placing the second silicon die offset from the first silicon die to expose the first contact pad surface.
19. The method of claim 15, wherein attaching the controller die to the substrate and attaching the flip chip die to the substrate include soldering contacts of each of the controller die and the flip chip die to the substrate, and applying underfill between the controller die and the substrate and between the flip chip die and the substrate.
20. The method of claim 15, wherein the flip chip die is configured as a single-level cell (SLC) memory and the first and second silicon dies are configured as one of a multi-level cell (MLC) memory, a triple-level cell (TLC) memory, and a quad-level cell (QLC) memory.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0022] Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. It also will be understood by those of skill in the art that the drawings are not to scale, where some features are exaggerated in order to highlight such features.
[0023]
[0024] The storage system 100 includes the host device 104 that may store and/or retrieve data to and/or from the storage device 106. As illustrated in
[0025] As illustrated in
[0026] The interface 114 of the storage device 106 may include one or both of a data bus for exchanging data with the host device 104 and a control bus for exchanging commands with the host device 104. The interface 114 may operate in accordance with any suitable protocol. For example, the interface 114 may operate in accordance with one or more of the following protocols: advanced technology attachment (ATA) (e.g., serial-ATA (SATA) and parallel-ATA (PATA)), Fibre Channel Protocol (FCP), small computer system interface (SCSI), serially attached SCSI (SAS), PCI, and PCIe, non-volatile memory express (NVMe), OpenCAPI, GenZ, Cache Coherent Interface Accelerator (CCIX), or the like. The interface 114 is communicatively connected (e.g., a data bus, a control bus, or other suitable connection) to the controller 108, allowing data to be exchanged between the host device 104 and the controller 108. In some examples, the interface 114 may also permit the storage device 106 to receive power from the host device 104.
[0027] The NVM 110 may be part of a packaged integrated circuit (IC) or other packaged silicon device, such as a memory device. The NVM 110 may also include read/write circuitry that reads data from and writes data to another portion of the memory device. For instance, the read/write circuitry of the NVM 110 may receive data and a message from the controller 108 that instructs the read/write circuitry to store the data in the NVM 110. Similarly, the read/write circuitry of the NVM 110 may receive a message from the controller 108 that instructs the read/write circuitry to retrieve data from the NVM 110. In some examples, each die (i.e., the controller 108 and memory dies making up the NVM 110 of the memory device) may be individually referred to as a silicon die.
[0028] In some examples, the memory device may include any type of non-volatile memory. For example, the NVM 110 may include flash memory or any other suitable non-volatile memory. Flash memory may include NAND-based or NOR-based flash memory, and may store data based on a charge contained in a floating gate of a transistor for each flash memory cell. In NAND-based flash memory, the flash memory may be divided into a plurality of blocks that may divided into a plurality of pages. Each block of the plurality of blocks may include a plurality of NAND cells. Rows of NAND cells may be electrically connected using a word line to define a page of a plurality of pages. Respective cells in each of the plurality of pages may be electrically connected to respective bit lines. Furthermore, the NAND-based flash memory may be 2D or 3D, and may be configured as SLC, MLC, TLC, or QLC.
[0029] The volatile memory 112 may be used by the controller 108 to store information. The volatile memory 112 may be comprised of one or more volatile memory devices. In some examples, the controller 108 may use the volatile memory 112 as a cache. For instance, the controller 108 may store cached information in the volatile memory 112 until the cached information is written to the NVM 110. Examples of the volatile memory 112 include, but are not limited to, random-access memory (RAM), dynamic random access memory (DRAM), static RAM (SRAM), and synchronous dynamic RAM (SDRAM (e.g., DDR1, DDR2, DDR3, DDR3L, LPDDR3, DDR4, LPDDR4, and the like)).
[0030] The controller 108 manages one or more operations of the storage device 106. For instance, the controller 108 manages the reading of data from and/or the writing of data to the NVM 110. In some embodiments, when the storage device 106 receives a write command from the host device 104, the controller 108 may initiate a data storage command to store data to the NVM 110 and monitor the progress of the data storage command. In other embodiments, the controller 108 may determine at least one operational characteristic of the storage system 100 and store the at least one operational characteristic in the NVM 110.
[0031]
[0032] The packaged IC 200 includes a substrate 202. A flip chip die 204 is mounted on the substrate 202. The flip chip die 204 is attached to the substrate 202 with a plurality of solder bumps 206 disposed between the flip chip die 204 and the substrate 202 for electrically connecting the flip chip die 204 to the substrate 202 (e.g., electrically connecting the contacts of the flip chip die 204 to wires or traces on or embedded in the substrate 202). A controller die 208 also is attached to the substrate 202 with a plurality of the solder bumps 206 disposed between the controller die 208 and the substrate 202. The solder bumps 206 may be made entirely or partially of one or more metallic or other conductive materials such as, for instance, gold, silver, palladium, iridium, indium, silver/tin amalgams, one or more binary or ternary metal alloys, lead, and the like. As illustrated, an underfill 210 may be disposed between respective ones of the flip chip die 204 and the controller die 208 and the substrate 202. In some embodiments, this arrangement of the flip chip die 204 and the controller die 208 may be attached to the substrate 202 during the same or a parallel assembling phase and at approximately the same time.
[0033] Also shown in the illustrated embodiment of
[0034] Each silicon die 212 includes a contact pad surface 214 including a contact pad. Opposite from the contact pad surface 214, an adhesive (such as, for example, a die attach film) 216 is used to adhere an adjacent silicon die 212 to a non-active surface of the flip chip die 204. The adhesive 216 attaches the first silicon die 212 to the flip chip die 204. Similarly, each subsequent silicon die 212 is adhered to the previous silicon die 212 by a respective layer of adhesive 216. In some embodiments, the stack of silicon dies 212 may be adhered to each other prior to adhering the stack to the flip chip die 204. In other embodiments, the silicon dies 212 may be added one or more at a time after initially attaching the first silicon die 212 to the flip chip die 204.
[0035] The contact pad surface 214 of each silicon die 212 faces away from the flip chip die 204. This arrangement allows for electrical connectors (e.g., bond wires), such as one or more wires 218, to electrically couple the silicon dies 212 to the substrate 202 (e.g., to wires or traces on or embedded in the substrate 202) and, therefore, to other electrical components (such as the controller die 208, for instance). In some embodiments, the wires 218 may be made entirely or partially of one or more metallic or other conductive materials such as, for instance, copper, aluminum, gold, palladium, indium, iridium, various silver/tin amalgams, lead, as well as binary and/or ternary metal alloys, and the like. In some embodiments, the wires 218 is a round or substantially round wires, but other embodiments may include wires 218 that are flat or ribbon-type wires.
[0036] To facilitate the connection of the wires 218 to the contact pad on the contact pad surface 214 of each silicon die 212, the illustrated embodiment of the packaged IC 200 includes the silicon dies 212 stacked in an offset manner, resembling a flight of stairs. Other embodiments may include different arrangements of the silicon dies 212. Some embodiments may include silicon dies 212 offset due to having varying sizes and/or shapes. Further, some embodiments include silicon dies 212 that are a different size and/or shape compared to the flip chip die 204. Although not shown in
[0037] Turning now to
[0038] The method 300 further includes attaching the flip chip die 204 to the substrate 202 (at block 302) as shown in
[0039] The method 300 also includes stacking the silicon dies 212 to a top surface of the flip chip die 204 (at block 303) as shown in
[0040] The method 300 further includes electrically connecting the silicon dies 212 to each other and to the substrate 202 (e.g., wires or traces on or embedded in the substrate 202) (at block 304), and thereby enabling electrical communication between the silicon dies 212 and other components of the packaged IC 200 such as, for instance, the controller die 208 as shown in
[0041] With reference to
[0042] As illustrated in
[0043] As shown in
[0044] As illustrated in
[0045] Turning now to
[0046] The method 600 further includes attaching the flip chip die 504 to the substrate (at block 602) as shown in
[0047] The method 600 also includes attaching silicon dies 512 to the substrate 502 (at block 603) as shown in
[0048] The method 600 further includes electrically connecting the stacked silicon dies 512 to each other and the substrate 502 (e.g., wires or traces on or embedded in the substrate 502) using bond wires, and thereby electrically connecting the silicon dies 512 to other components of the packaged IC 500 such as, for instance, the controller die 508 (at block 604) as shown in
[0049] The methods described above may be implemented, in some embodiments, with no extra assembling steps in the assembling process compared to prior art assembling techniques. Stated another way, the methods described herein can provide for an improved memory device without requiring longer assembling times. One or more of the above described embodiments may allow for improved read/write speeds, improved electrical performance, improved thermal performance, more flexible use of the various dies, and the like.
[0050] In particular, the flip chip die may be used by the controller die to store data at a high frequency and/or at demanding high read/write speeds. In addition, the silicon dies may be used by the controller die to store data at lower frequencies relative to the flip chip die and at less demanding lower read/write speeds. The thermal performance may be improved by, for instance, distancing the silicon dies from the substrate with the flip chip die (and, in some embodiments, also with the controller die). This additional distance allows the silicon dies to more efficiently transfer heat to the environment instead of transferring heat into the substrate. Stated another way, the flip chip die may, in some embodiments, improve thermal isolation between the silicon dies and the substrate.
[0051] In this regard, a preferred embodiment of the present disclosure is for the flip chip die and the stacked silicon dies all to comprise NAND dies, and further that the flip chip die is configured as SLC memory and the stacked dies are configured as one of MLC memory, TLC memory, or QLC memory. Then, firmware in the controller die is used to read and write “hot” data to the SLC memory (i.e., the flip chip die), and in the background, data can be moved from the SLC memory to the one of the MLC memory, the TLC memory, or the QLC memory. As electrical signals may travel faster between the controller die and the flip chip die, it is advantageous to first store data in the SLC memory of the flip chip die followed by storing the data in the one of the MLC, the TLC, or the QLC memory.
[0052] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the present disclosure should be determined by the following claims.