Heat dissipation system of chip

Abstract

The invention relates to the technical field of chip packaging heat dissipation, in particular to a chip heat dissipation system which comprises a thermoelectric film layer, a micro-scale radiator layer and a micro pump, the thermoelectric film layer comprises a hot end, a cold end and a power generation layer, the hot end is connected with the surface of a chip, the cold end is connected with a heat dissipation substrate of a micro-scale radiator, and the power generation layer is connected with the heat dissipation substrate. The power generation layer is used for forming electromotive force according to the temperature difference between the hot end and the cold end and outputting power supply voltage. The micro-scale radiator layer comprises a radiating substrate, and a circulating liquid inlet and a circulating liquid outlet are formed in the radiating substrate; the micro pump layer is provided with a pump liquid inlet and a pump liquid outlet, the pump liquid inlet is connected with the circulating liquid outlet, and the pump liquid outlet is connected with the circulating liquid inlet; the micro-pump layer further comprises a piezoelectric part, the piezoelectric part is communicated with power supply voltage and used for driving liquid in the micro-pump to circularly flow in the micro-scale radiator layer and the micro-pump layer through the voltage, heat is recycled to generate power so that the micro-pump can drive the liquid to circularly dissipate heat, external power supply is not needed, and the purpose of self-sufficiency is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging heat dissipation, and particularly to a heat dissipation system for a chip. Background Art

[0002] At present, chip packaging heat dissipation systems include two types. The first type is a bare die heat dissipation system. When dissipating heat from a bare die, there is no packaging cover plate, and a layer of thermal interface material is directly filled between the bare die and the radiator for heat dissipation. The second type is a heat dissipation system with a packaging cover plate. A layer of thermal interface material is filled between the bare die and the packaging cover plate, and another layer of thermal interface material is filled between the packaging cover plate and the radiator. Both of these two types of heat dissipation systems need to transfer heat through the thermal interface material. However, each additional layer of thermal interface material will bring a temperature rise of 3 to 5 degrees, and the heat dissipation capacity is less than 100 W per square meter, resulting in low heat dissipation efficiency.

[0003] The integration degree of chips is getting higher and higher. For high-power chips, the requirements for heat dissipation are also getting higher and higher. Both of the above two heat dissipation systems have the following technical problems:

[0004] First, for the packaged chip device, the heat dissipation intensity can be enhanced by installing an impeller pump with a size larger than the chip device. However, due to the rotating mechanical structure of the traditional impeller pump, the volume cannot be made very small and cannot be integrated into the chip packaging structure. Therefore, the heat dissipation efficiency cannot be improved, nor can the requirements of high-power chips be met.

[0005] Second, a large amount of heat energy is released during the heat dissipation process of the traditional heat dissipation system, resulting in heat energy loss.

[0006] Third, due to the low heat dissipation efficiency of the traditional heat dissipation system, 3D packaging of high-power chips cannot be achieved. Summary of the Invention

[0007] In view of the above technical problems, the technical solution adopted by the present invention is: a heat dissipation system for a chip, the system includes a thermoelectric thin film layer, a microscale radiator layer, and a micro pump. Among them: the thermoelectric thin film layer includes a hot end, a cold end, and a power generation layer. The hot end is connected to the surface of the chip, the cold end is connected to the heat dissipation substrate of the microscale radiator, and the power generation layer is used to form an electromotive force according to the temperature difference between the hot end and the cold end and output a supply voltage; the microscale radiator layer includes a heat dissipation substrate, and a circulating liquid inlet and a circulating liquid outlet are arranged inside the heat dissipation substrate; the micro pump layer is provided with a pump liquid inlet and a pump liquid outlet, the pump liquid inlet is connected to the circulating liquid outlet, and the pump liquid outlet is connected to the circulating liquid inlet; the micro pump layer further includes a piezoelectric component, and the piezoelectric component is connected to the supply voltage and is used to drive the liquid in the micro pump to circulate between the microscale radiator layer and the micro pump layer through voltage.

[0008] The present invention has at least the following beneficial effects:

[0009] A heat dissipation system for a chip provided in the third embodiment of the present invention recovers the heat of the chip through a thermoelectric thin film layer to generate electricity, so as to drive a piezoelectric component of a micro pump to circulate and dissipate heat in the micro pump and the micro-scale radiator, forming a complete circulating heat dissipation system. It can not only recover the heat generated by the chip, but also generate electricity through the recovered heat to drive the micro pump to circulate and dissipate heat by using liquid, without the need for external power supply, achieving the purpose of self-sufficiency. Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0011] Figure 1 It is a schematic structural diagram of a micro pump provided in the first embodiment of the present invention;

[0012] Figure 2 It is a schematic diagram of the state comparison of the micro pump in the liquid inlet and outlet state provided in the first embodiment of the present invention;

[0013] Figure 3 It is a schematic diagram of a heat dissipation system provided in the second embodiment of the present invention;

[0014] Figure 4 It is a schematic diagram of the heat dissipation system when the chip is flip-chip mounted provided in the second and third embodiments of the present invention;

[0015] Figure 5 It is a schematic diagram of the heat dissipation system when the chip is wire-bonded and packaged provided in the second and third embodiments of the present invention;

[0016] Figure 6 It is a schematic diagram of the heat dissipation system for realizing internal and external liquid circulation through blind insertion provided in the third embodiment of the present invention;

[0017] Figure 7 It is a schematic structural diagram of a 3D package heat dissipation system provided in the fourth embodiment of the present invention;

[0018] Figure 8 It is a schematic diagram of the system sharing a micro pump provided in the fourth embodiment of the present invention. Detailed Embodiments

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0020] To solve the first technical problem, Embodiment 1 is provided in the embodiments of the present invention.

[0021] Embodiment 1

[0022] Please refer to Figure 1 and Figure 2 , Figure 1 , which shows a schematic structural diagram of a micropump, Figure 2 , which shows a schematic diagram of the state comparison of the micropump in the liquid inlet and outlet states. The micropump 1000 includes a pump body 10, a cavity 101 is provided in the pump body 10, and a pump liquid inlet 11 and a pump liquid outlet 12 communicated with the cavity 101; wherein, a liquid inlet switch 111 is provided at the pump liquid inlet 11, and a liquid outlet switch 121 is provided at the pump liquid outlet 12; a notch 13 is further provided on the inner wall of the cavity of the pump body 10, and a piezoelectric component 14 is provided in the notch 13; when the piezoelectric component 14 is powered on, the piezoelectric component 14 has a first state 141 of extending towards the outside of the cavity along the notch to expand the cavity volume and a second state 142 of extending towards the inside of the cavity to contract the cavity volume; when the piezoelectric component 14 switches between the first state 141 and the second state 142, the micropump 1000 switches between the liquid inlet state 110 and the liquid outlet state 120; wherein, the liquid inlet state 110 is: when the piezoelectric component 14 is in the first state, the liquid inlet switch 111 is opened under the pressure of the external liquid, and the liquid enters the cavity 101 from the outside through the pump liquid inlet 11; the liquid outlet state 120 is: when the piezoelectric component 14 is in the second state 142, the liquid outlet switch 121 is opened under the pressure of the internal liquid, and the liquid flows out of the cavity 101 from the pump liquid outlet 12.

[0023] Among them, the cavity 101 is used to hold liquid.

[0024] Among them, the pump body 10, the liquid inlet switch 111 and the liquid outlet switch 121 are all made of non-conductive materials.

[0025] As a preferred embodiment, the piezoelectric component 14 is made of piezoelectric material, and the piezoelectric component is connected to a power supply. Preferably, the piezoelectric material is lead zirconate titanate (PbZrxTi1-xO3, PZT).

[0026] As a preferred embodiment, the piezoelectric component 14 includes a variable elastic member and a piezoelectric ceramic member, the piezoelectric ceramic member is provided on the variable elastic member, and the piezoelectric ceramic member is connected to a power supply.

[0027] Other piezoelectric components used in the prior art to convert electrical signals into mechanical signals all fall within the protection scope of the present invention.

[0028] Wherein, the piezoelectric component 14 can cover the notch and jointly form a sealed cavity with the pump body, the liquid inlet switch, the pump liquid inlet, the liquid outlet switch, and the pump liquid outlet.

[0029] Wherein, the pump body 10 provided with a cavity 101, the pump liquid inlet 11 provided with a liquid inlet switch 111 on the pump body, the pump liquid outlet 12 provided with a liquid outlet switch 121, and the cavity 101 surrounded by the notch 13 provided with the piezoelectric component 14 can accommodate liquid. When the piezoelectric component 14 switches between the first state 141 and the second state 142, the pressure inside the cavity 101 is changed. According to the action of the pressure on the liquid inlet and outlet switches, the cyclic flow of the liquid is ingeniously realized. The action of the pressure on the liquid inlet and outlet switches is specifically as follows: when the internal pressure is greater than the external pressure, the liquid outlet switch 121 opens, and the liquid flows to the outside of the cavity 101; when the external pressure is greater than the internal pressure, the liquid inlet switch 111 opens, and the liquid flows from the outside to the inside of the cavity 101.

[0030] As a preferred embodiment, the upper end of the liquid inlet switch 111 is rotatably connected to the upper end of the pump liquid inlet 11. The lower end of the pump liquid inlet 11 is provided with a liquid inlet protrusion 112 on the pump body 10. The side of the liquid inlet protrusion 112 close to the cavity 101 is used to block the lower end of the liquid inlet switch 111. Since the liquid inlet switch 111 is placed on the side of the liquid inlet protrusion 112 close to the cavity 101, when the external pressure is greater than the internal pressure, the liquid inlet switch 111 is squeezed under the action of the liquid pressure. Since there is no blockage inside the cavity 101 when squeezing the liquid inlet switch 111 from the outside to the inside of the cavity 101, the liquid inlet switch 111 rotates inward, that is, rotates in the opposite direction of the liquid inlet protrusion 112, and the liquid flows from the outside into the cavity 101. On the contrary, if the pressure of the liquid inside the cavity 101 is greater than the outside, the liquid squeezes the liquid inlet switch 111. Since the liquid inlet protrusion 112 is provided outside the liquid inlet switch 111, the liquid inlet protrusion 112 blocks the rotation of the liquid inlet switch 111, and the liquid inlet switch 111 closes the pump liquid inlet 11. Through the cooperation of the pump liquid inlet switch 111, the liquid inlet protrusion 112, and the piezoelectric component 14, the liquid in the micropump 1000 can circulate.

[0031] As a preferred embodiment, the upper end of the liquid outlet switch 121 is rotatably connected to the upper end of the pump liquid outlet 12. A liquid outlet protrusion 122 is provided on the pump body at the lower end of the pump liquid outlet 12. The side of the liquid outlet protrusion 122 away from the cavity 101 is used to block the lower end of the liquid outlet switch 121. Similarly, due to the blocking effect of the liquid outlet protrusion 122, when the pressure of the external liquid is greater than the internal pressure, the liquid outlet protrusion 122 blocks the liquid outlet switch 121, and the liquid outlet switch 121 closes the pump liquid outlet 12. When the pressure of the liquid inside the cavity 101 is greater than the external pressure, the liquid outlet switch 121 rotates in the opposite direction of the liquid outlet protrusion 122 to open the liquid outlet, and the liquid flows out from inside the cavity 101. Through the cooperation of the pump inlet switch 111, the inlet protrusion 112, the pump outlet switch 121, the outlet protrusion 122, and the piezoelectric component 14, the liquid in the micropump can circulate, and the piezoelectric component 14 changes the internal and external pressure difference by changing the internal volume of the cavity 101, realizing the opening or closing of the inlet and outlet switch 121 through the pressure difference, achieving automatic liquid circulation, and eliminating the need for a traditional rotating mechanical structure. In the embodiment of the present invention, the structure of the micropump is simple, without a traditional rotating mechanical structure, and can be made very small for the micropump and integrated into the chip.

[0032] As a preferred embodiment, the pump inlet of the micropump is connected to the circulating liquid outlet of the microscale radiator, and the pump outlet of the micropump is connected to the circulating liquid inlet of the microscale radiator to form a liquid circulation loop. The liquid in the micropump and the microscale radiator realizes circulating heat dissipation. By the micropump, the efficiency of liquid circulating heat dissipation in the microscale radiator layer is increased, and the area of circulating heat dissipation is increased. The liquid in the micropump is far away from the heat-generating chip and can be used as a condensation end to achieve a better condensation effect and improve the heat dissipation efficiency. Among them, the microscale radiator is connected to the chip for dissipating heat from the chip.

[0033] As a preferred embodiment, the microscale radiator includes an inlet and outlet pipe. A first inlet and outlet through hole is provided on the packaging substrate. The inlet and outlet pipe of the microscale radiator passes through the first inlet and outlet through hole, and a packaging end blind plug connector is provided at the end of the inlet and outlet pipe extending out of the packaging substrate. Among them, the packaging substrate is a carrier for chip packaging and is used for packaging.

[0034] As a preferred embodiment, the inlet and outlet pipe is connected to the board-end blind plug connector of the circuit board through a blind plug connector, and the board-end blind plug connector is connected to an external inlet and outlet pipe, and the external inlet and outlet pipe is arranged through the second inlet and outlet through hole on the circuit board. Among them, the circuit board is a PCB circuit board for carrying and installing the packaged chip. The blind plug connectors in the prior art all fall within the protection scope of the present invention.

[0035] Among them, the inlet and outlet liquid pipes of the micro-scale radiator are set as a blind plug structure, which can not only achieve one-key installation during installation, simplify the installation steps, but also be configured as a standardized structure on the packaging module and the circuit board. The inlet and outlet liquid pipes are arranged under the circuit board, which can save space and make the structure more regular. At the same time, as a standardized structure, it is also convenient for operations such as replacement and disassembly.

[0036] Optionally, the power supply of the micro pump is the chip power supply or an external independent power supply.

[0037] As a preferred embodiment, the power supply of the micro pump is a thermoelectric thin film layer. The thermoelectric thin film layer is a thermoelectric thin film. Preferably, the thermoelectric thin film layer is a lithography material and is integrated into the chip by lithography. The lithography material is an alloy based on bismuth telluride.

[0038] As a preferred embodiment, the thermoelectric thin film layer includes a hot end, a cold end and a power generation layer. The hot end is connected to the surface of the chip, the cold end is connected to the heat dissipation substrate of the micro-scale radiator, and the power generation layer is used to form an electromotive force according to the temperature difference between the hot end and the cold end and output the power supply. Among them, the power generation layer includes a PN junction array composed of a P-type semiconductor and an N-type semiconductor. The PN junction array is connected in series through a first conductive sheet and a second conductive sheet to form the electromotive force accumulated by all PN junctions in the PN junction array. The series connection of the PN junction array can increase the electromotive force. Among them, both the hot end and the cold end are ceramic plates, and the ceramic plates are non-conductive and thermally conductive.

[0039] As a preferred embodiment, when the micro pump is used as a micro pump layer and is connected to the micro-scale radiator layer to dissipate heat from the chip, the micro pump layer includes a plurality of serially connected micro pumps, and the working states of the piezoelectric components of adjacent micro pumps are different. It should be noted that the series connection of the micro pumps is achieved by connecting the inlet and outlet ports of the micro pumps in series. The series connection of the micro pumps can increase the overall head of the micro pump layer. The working states of the piezoelectric components of adjacent micro pumps are different, and the different working states of the piezoelectric components cause the inlet and outlet liquid states of adjacent micro pumps to be different. For example, when the piezoelectric component of the current micro pump is in the first state, the piezoelectric component of the adjacent micro pump is in the second state, that is, the current micro pump is in the liquid inlet state and the adjacent micro pump is in the liquid outlet state.

[0040] Optionally, the piezoelectric component is a MEMS sensor. The micro pump is driven by a Micro-Electro-Mechanical System (MEMS), and the volume of the micro pump can be made very small, which is easy to integrate inside the chip stack or package. It cooperates with the micro-scale radiator to achieve extreme cooling of the chip. The cooling power is greater than 1000 W per square centimeter, while the power required by the micro pump itself is in the mW level, and the power consumption is very small.

[0041] In summary, Embodiment 1 of the present invention provides a micropump, which includes a pump body with a cavity. There is a notch on the inner wall of the cavity of the pump body, and a piezoelectric component is arranged in the notch. The piezoelectric component has a first state of increasing the volume of the cavity and a second state of contracting the volume of the cavity; when switching between the first state and the second state, the pressure inside the cavity is changed, and according to the effect of the pressure on the liquid inlet and outlet switch, the switching between the liquid inlet state and the liquid outlet state is realized, and thus the cyclic flow of the liquid is ingeniously realized. Therefore, the volume of the micropump can be made very small and integrated onto a chip. Embodiment 1 of the present invention solves the technical problem that the existing traditional impeller water pump cannot have a very small volume due to the existence of a rotating mechanical structure and cannot be applied to on-chip integration of a chip.

[0042] Since the heat generated by the chip is dissipated not only through the radiator, but also an additional power supply is needed to drive the micropump to better assist in heat dissipation. The heat dissipation system consumes both heat and electrical signals, resulting in a waste of energy. Therefore, there is an urgent need for a heat dissipation system that can make full use of energy, and Embodiment 2 of the present invention is provided.

[0043] Embodiment 2

[0044] Please refer to FIG. 3, which shows a schematic structural diagram of a heat dissipation system. The system includes a thermoelectric thin film layer 200 and a microscale radiator layer, wherein: the thermoelectric thin film layer 200 includes a hot end 210, a cold end 220, and a power generation layer 230. The hot end 210 is connected to the surface of the chip, and the cold end 220 is connected to the heat dissipation substrate of the microscale radiator; the power generation layer 230 is located between the hot end 210 and the cold end 220 and is used to form an electromotive force according to the temperature difference between the hot end 210 and the cold end 220 and output a supply voltage; wherein, the power generation layer 230 includes a series-connected PN junction array, and each PN junction includes a P-type semiconductor 231, an N-type semiconductor 232, a first conductive sheet 234, and a second conductive sheet 233. The PN junction array is connected in series through the first conductive sheet 234 and the second conductive sheet 233. The connection structure of the first conductive sheet 234 and the second conductive sheet 233 of the i-th PN junction includes: one side of the first conductive sheet 234 of the i-th PN junction is connected to the hot end 210, and one side of the second conductive sheet 233 is connected to the cold end 220; the first conductive sheet 234 and the second conductive sheet 233 are respectively connected to different ends of the P-type semiconductor 231 and the N-type semiconductor 232 of the i-th PN junction, and the first conductive sheet 234 and the second conductive sheet 233 are cross-connected to different PN junctions so that the electromotive forces accumulated by all the PN junctions in the PN junction array are obtained by series connection of the PN junctions.

[0045] Optionally, the chip is a memory chip or a high-power chip. Among them, the memory chip can be HBM or DDR, etc. The high-power chip can be SOC or GPU, etc.

[0046] Among them, both the hot end 210 and the cold end 220 are insulating and heat-conducting components. Optionally, the insulating and heat-conducting component is insulating ceramic. The surface heat generation of the chip is the heat source, and the insulating ceramic connected to the heat source is the hot end 210. The microscale radiator is used for heat dissipation, and the insulating ceramic connected to the heat dissipation substrate of the microscale radiator is the cold end 220. It should be noted that ceramics are divided into insulating ceramics and conductive ceramics. The hot end 210 and the cold end 220 only need to conduct heat, so insulating ceramics are used. Optionally, the hot end 210 and the cold end 220 are aluminum nitride ceramics or silicon carbide ceramics, and other ceramics with heat conduction and insulation in the prior art all fall within the protection scope of the present invention.

[0047] It should be noted that the thermoelectric thin film layer 200 in the second embodiment is the same as that in the first embodiment. For the same parts, please refer to the first embodiment.

[0048] Among them, one end of the power generation layer 230 is connected to the hot end 210, and the other end is connected to the cold end 220. The connection here means that one side of the power generation layer 230 is attached to the other side of the hot end 210. The side of the power generation layer 230 attached to the hot end 210 is different from the side attached to the surface of the chip, and is the two opposite sides of the hot end 210. Similarly, the side of the power generation layer 230 attached to the cold end 220 is different from the side attached to the heat dissipation substrate, and is the two opposite sides of the cold end 220. The two sides of the power generation layer 230 attached to the hot end 210 and the cold end 220 respectively are different, and are the two opposite sides of the power generation layer 230. Among them, the side of the power generation layer 230 attached to the hot end 210 is composed of the first conductive sheets 234 of all PN junctions, and the side of the power generation layer 230 attached to the cold end 220 is composed of the second conductive sheets 233 of all PN junctions.

[0049] As a preferred embodiment, the power generation layer 230 further includes positive and negative electrodes, which are respectively arranged on the conductive sheets connecting different semiconductors at the head and tail ends of the PN junction array. The electromotive force between the positive and negative electrodes forms a supply voltage. It should be noted that the positive electrode 236 of the power generation layer 230 is connected to one end of the piezoelectric component, and the negative electrode 235 of the power generation layer 230 is connected to the other end of the piezoelectric component.

[0050] As a preferred embodiment, the system further includes a micro pump. The micro pump includes a piezoelectric component, and the piezoelectric component is connected to the supply voltage. The supply voltage causes the piezoelectric component to switch between a first state and a second state, driving the circulating flow of the liquid in the micro pump. Among them, the micro pump is the same as the micro pump in the first embodiment. Please refer to the first embodiment and will not be elaborated here.

[0051] Optionally, when the other side of the first conductive sheet 234 of the i-th PN junction is respectively connected to one end of the P-type semiconductor 231 and one end of the N-type semiconductor 232 of the i-th PN junction; the other side of the second conductive sheet 233 of the i-th PN junction is respectively connected to the other end of the N-type semiconductor 232 of the i-th PN junction and one end of the P-type semiconductor 231 in the adjacent PN junction.

[0052] Optionally, when the other side of the second conductive sheet 233 of the i-th PN junction is respectively connected to one end of the P-type semiconductor 231 and one end of the N-type semiconductor 232 of the i-th PN junction; the other side of the first conductive sheet 234 of the i-th PN junction is respectively connected to the other end of the N-type semiconductor 232 of the i-th PN junction and one end of the P-type semiconductor 231 in the adjacent PN junction.

[0053] Wherein, the P-type semiconductor and the N-type semiconductor need to be semiconductor materials and thermoelectric materials capable of fabricating PN junctions at the same time, and PN junctions can be processed by lithography materials or microelectromechanical systems (MEMS) to form PN junction thermoelectric thin films. Processing PN junctions by lithography materials or microelectromechanical systems (MEMS) can integrate the thermoelectric thin film layer onto the chip surface and package it together with the chip. The characteristics of the thermoelectric material and the semiconductor material enable the thermoelectric thin film layer to convert thermal energy into electrical energy.

[0054] Optionally, the P-type semiconductor and the N-type semiconductor are bismuth telluride-based alloys. The P-type semiconductor is a lead telluride (Bi2Te3-Sb2Te3) alloy based on bismuth telluride, and the N-type semiconductor is a bismuth selenide (Bi2Te3-Bi2Se3) alloy based on bismuth telluride; or the P-type semiconductor is a lead bismuth telluride alloy, and the N-type semiconductor is a bismuth telluride selenium alloy.

[0055] As a preferred embodiment, the P-type semiconductor is a bismuth telluride antimony-doped alloy, and the N-type semiconductor is a bismuth telluride selenium-doped alloy.

[0056] As a preferred embodiment, please refer to Figure 4, when the chip in the packaging structure is flip-chip, the integrated heat dissipation system in the packaging structure sequentially includes a thermoelectric thin film layer 200, a microscale heat sink layer 300, and a micro pump layer 100 from bottom to top, wherein the thermoelectric thin film layer 200 is located above the chip layer 400. Among them, the flip-chip packaging structure includes a packaging substrate 600, an interposer 500, and a chip layer 400 connected in sequence from bottom to top. After chip packaging, the packaged chip is mounted on a PCB circuit board 700. The microscale heat sink layer 300 realizes liquid circulation heat dissipation through the liquid inlet and outlet pipes 310, and between the microscale heat sink layer 300 and the micro pump 100 through the micro pump liquid inlet 11 and the pump liquid outlet 12. Other flip-chip packaging structures in the prior art all fall within the protection scope of the present invention. It should be noted that the liquid inlet and outlet pipes 310 of the microscale heat sink are the liquid inlet pipe and the liquid outlet pipe, belonging to two different pipes, and the liquid inlet and outlet pipes 310 in the figure are only schematic diagrams of the pipe positions.

[0057] As a preferred embodiment, please refer to Figure 5 , when the chip in the packaging structure is packaged by wire bonding, the integrated heat dissipation system in the packaging structure sequentially includes a thermoelectric thin film layer 200, a microscale heat sink layer 300, and the micro pump layer 100, wherein the thermoelectric thin film layer 200 is connected to the side of the chip layer 400 close to the packaging substrate 600, the other side of the thermoelectric thin film layer 200 relative to the chip layer 400 is connected to the microscale heat sink layer 300, and the thermoelectric thin film layer 200 and the microscale heat sink layer 300 are located between the chip layer 400 and the packaging substrate layer 600, and the micro pump layer 100 is located above the chip layer 400. When there is an interposer 500 in the packaging structure, the chip layer 400 is connected to the packaging substrate layer 600 through the interposer 500. Since the wire bonding packaging structure is different from the flip-chip packaging structure, the wire bonding packaging structure makes there be two layers between the microscale heat sink layer 300 and the micro pump layer 100. In Figure 5 , the position structure of the pump liquid outlet 12 is schematically shown, and they need to be connected through the pump liquid outlet 12 and the pump liquid inlet.

[0058] In the embodiment of the present invention, a thermoelectric thin film layer 200, a microscale heat sink layer 300, and a micro pump layer 100 are sequentially integrated on the chip layer 400 to form a complete heat dissipation system to assist the chip in heat dissipation. This heat dissipation system can not only fully recover waste heat and improve the energy utilization rate, but also fully dissipate heat, and the heat dissipation power is greater than 1000 W per square centimeter.

[0059] Optionally, the thermoelectric thin film layer is formed by photolithography, or formed by photolithography and etching on a silicon wafer. The thickness of the thermoelectric thin film layer is in the micron range.

[0060] Optionally, the microscale heat sink layer is integrated into the chip by lithography. Among them, the material of the microscale heat sink layer is eutectic alloy or pure silicon. When the material of the microscale heat sink layer is eutectic alloy, the eutectic soldering process is adopted. The contact thermal resistance of eutectic soldering is the smallest. Pure silicon is non-conductive, and the directly lithographed microscale channels have no contact thermal resistance and extremely high heat conduction ability, so the heat dissipation ability of the microscale heat sink is greatly improved.

[0061] In the second embodiment of the present invention, the thermoelectric thin film layer is respectively connected to the heat dissipation substrate of the chip and the microscale heat sink to realize waste heat recovery. The thermoelectric thin film layer has a small self-thermal resistance, can obtain a high waste heat utilization efficiency, and has little impact on the chip. It solves the technical problem that a large amount of heat energy is released during the heat dissipation process of the traditional heat dissipation system, resulting in heat energy loss.

[0062] Although the micro pump provided in the first embodiment can quickly circulate the liquid in the microscale heat sink under the drive of the micro pump, since the electrical signal required by the micro pump needs to be provided by the outside, there are both electrical signal consumption and heat energy consumption in the heat dissipation system, resulting in various energy losses. Therefore, in order to make the heat dissipation system no longer rely on the electrical signal provided by the outside for circulating heat dissipation and achieve the purpose of self-sufficiency, the third embodiment of the present invention is provided.

[0063] Embodiment Three

[0064] Please refer to Figure 4 and Figure 5 , both of which show a schematic structural diagram of a heat dissipation system of a chip. The system includes a micro pump layer, a thermoelectric thin film layer 200, and a microscale heat sink layer 300. Among them: the thermoelectric thin film layer 200 includes a hot end, a cold end, and a power generation layer. The hot end is connected to the surface of the chip, the cold end is connected to the heat dissipation substrate of the microscale heat sink, and the power generation layer is used to form an electromotive force according to the temperature difference between the hot end and the cold end and output a supply voltage; the microscale heat sink layer 300 includes a heat dissipation substrate, and a circulating liquid inlet and a circulating liquid outlet are arranged inside the heat dissipation substrate; the micro pump layer is provided with a pump liquid inlet and a pump liquid outlet. The pump liquid inlet is connected to the circulating liquid outlet, and the pump liquid outlet is connected to the circulating liquid inlet; the micro pump layer further includes a piezoelectric component, and the piezoelectric component is connected to the supply voltage and is used to drive the liquid in the micro pump to circulate between the microscale heat sink layer 300 and the micro pump layer through voltage. The heat dissipation capacity of this system is far greater than 1000 W per square centimeter. The pump liquid inlet 11 and the pump liquid outlet 12 connecting the micro pump layer 100 and the microscale heat sink layer 300 are shown in the figure, and the circulating liquid inlet and the circulating liquid outlet are not shown in the figure.

[0065] It should be noted that other technical details of the micropump in the first embodiment and other technical details of the thermoelectric thin film layer in the second embodiment are applicable to the third embodiment and will not be elaborated here.

[0066] Optionally, the micropump layer has one or more micropumps.

[0067] Among them, the microscale heat sink includes a heat dissipation substrate and heat dissipation fins. A heat spreading structure is provided in the heat dissipation substrate. The heat spreading structure includes a heat dissipation cavity, a capillary adsorption structure, and a liquid. The capillary adsorption structure adsorbs the liquid and is provided on the inner wall of the heat dissipation cavity; the capillary adsorption structure near the cold end is the evaporation end, and the capillary adsorption structure far from the evaporation end is the condensation end; when the liquid at the evaporation end absorbs the heat transferred from the cold end, it evaporates into steam, and the steam flows to the condensation end for heat dissipation and condensation under the action of the internal pressure difference in the cavity, forming a circulating heat dissipation system. The heat dissipation fins are used for heat dissipation. Among them, the heat dissipation cavity of the microscale heat sink is also provided with a liquid inlet main pipe and a liquid outlet main pipe, and the liquid inlet main pipe and the liquid outlet main pipe are used to circulate the liquid in and out of the heat dissipation cavity.

[0068] Optionally, the material of the microscale heat sink is a eutectic alloy body or pure silicon, and it is integrated into the chip by photolithography. The microscale heat sink uses a eutectic soldering process to generate a eutectic alloy body, and the eutectic alloy body has the smallest contact thermal resistance. Pure silicon is non-conductive, and the internal channels of the directly photolithographed microscale heat sink have no contact thermal resistance, and the heat conduction ability is extremely high. The heat dissipation ability of the microscale heat sink is strong.

[0069] It should be noted that the heat dissipation structures of flip-chip packaging and wire bonding packaging in the second embodiment are applicable to the third embodiment.

[0070] Among them, the packaging structure of the chip includes a chip layer 400, an interposer layer 500, and a packaging substrate 600.

[0071] As a preferred embodiment, please refer to Figure 6 , a first liquid inlet and outlet through hole 610 is provided on the packaging substrate 600, the liquid inlet and outlet pipe 310 of the microscale heat sink layer 300 passes through the first liquid inlet and outlet through hole 610, and a packaging end blind plug joint 311 is provided at the end of the liquid inlet and outlet pipe 310 extending out of the packaging substrate 600. Optionally, in the middle of the liquid inlet and outlet pipe 310 extending from the microscale heat sink layer 300 into the first liquid inlet and outlet through hole 610, it can pass through the through hole of the interposer layer 500 or bypass the interposer layer.

[0072] As a preferred embodiment, the system further includes a circuit board 700 and an external liquid inlet and outlet pipe 320, the circuit board 700 is provided with a second liquid inlet and outlet through hole 710, the end of the external liquid inlet and outlet pipe 320 extending out of the circuit board 700 through the second liquid inlet and outlet through hole 710 is provided with a board end blind plug connector 321; when the packaging structure is connected to the circuit board, the packaging end blind plug connector is connected to the board end blind plug connector, Figure 6 The state shown in is a schematic diagram of the package end blind plug connector 311 and the board end blind plug connector 321 after being plugged into one body. The blind plug structure can connect the inlet and outlet liquid pipes through the blind plug structure while assembling the packaged chip on the circuit board, and surround the external circulation pipeline on the back of the circuit board, so that the liquid circulates inside and outside the packaged chip for heat dissipation. The blind plug structure is not only easy to install, but also has a regular structure, without redundant pipelines, and will not cause a cluttered burden on the space of the circuit board.

[0073] Preferably, the first liquid inlet and outlet through hole is drilled by photolithography or a similar photolithography process, and the second liquid inlet and outlet through hole is drilled by a MEMS manufacturing process (Microelectromechanical systems, MEMS), wherein MEMS is mechanical drilling or laser drilling.

[0074] Preferably, the package-end blind-plug connector, the board-end blind-plug connector and the external liquid inlet and outlet pipes are mounted on the PCB surface by surface mount technology (SMT), thereby miniaturizing the heat dissipation system.

[0075] As a preferred embodiment, the power generation layer includes a PN junction array connected in series, each PN junction includes a P-type semiconductor, an N-type semiconductor, a first conductive plate and a second conductive plate, and the PN junction array is connected in series through the first conductive plate and the second conductive plate, wherein the connection structure of the first conductive plate and the second conductive plate of the i-th PN junction includes: one side of the first conductive plate of the i-th PN junction is connected to the hot end, and one side of the second conductive plate is connected to the cold end; the first conductive plate and the second conductive plate are respectively connected to different ends of the P-type semiconductor and the N-type semiconductor of the i-th PN junction, and the first conductive plate and the second conductive plate are alternately connected to different PN junctions, so that the PN junctions are connected in series to obtain the accumulated electromotive force of all PN junctions in the PN junction array.

[0076] It should be noted that the relevant technical details about the power generation layer in the second embodiment are applicable to the third embodiment and will not be repeated here.

[0077] Preferably, the thermoelectric film layer is photolithographically formed on the chip, and the microscale heat sink layer is photolithographically formed on the thermoelectric film layer 200. The photolithographic materials of the thermoelectric film layer and the microscale heat sink layer are the same as those in the second embodiment, and will not be described in detail.

[0078] Preferably, please refer back to Figure 4-6 , the thermoelectric thin film layer 200, the microscale radiator layer 300 and the micro pump layer 100 are all integrally packaged with the chip layer 400. Not only can the heat dissipation system be placed inside the chip packaging structure, but also with the mutual cooperation of the thermoelectric thin film layer 200, the microscale radiator layer 300 and the micro pump layer 100, the heat dissipation capacity of the heat dissipation system can be greatly improved, and self-sufficiency can be achieved. Among them, the technical details about the micro pump in the first embodiment can all be applied to the third embodiment of the present invention.

[0079] As a preferred embodiment, a thermoelectric thin film layer and a microscale radiator layer are configured for each layer of chips. Due to the substantial improvement in heat dissipation capacity, multi-layer stacking of chips can be realized. Each layer of chips is equipped with a set of heat dissipation systems, and its heat dissipation capacity can be greatly improved, and the heat dissipation capacity is far greater than 1000 W per square centimeter, far meeting the heat dissipation requirements of the chips.

[0080] As a preferred embodiment, a micro pump layer is configured for each chip layer, or all chip layers share a micro pump layer, and the thermoelectric thin film layer supplies power to the piezoelectric component in the micro pump. Based on the composite structure of the thermoelectric thin film layer, the microscale radiator layer and the micro pump layer with multi-layer stacking, waste heat recovery is realized and the micro pump is driven to work, realizing self-sufficiency in chip cooling, and an integrated chip packaging cooling unit can be achieved.

[0081] A heat dissipation system for a chip provided in the third embodiment of the present invention is composed of a thermoelectric thin film layer, a microscale radiator layer and a micro pump. The thermoelectric thin film layer generates electricity by recovering the heat of the chip to supply power to the piezoelectric component of the micro pump to drive the liquid to circulate and dissipate heat in the micro pump and the microscale radiator, forming a complete circulating heat dissipation system. It can not only recover the heat generated by the chip, but also generate electricity through the recovered heat to supply power for the micro pump to drive the liquid to circulate and dissipate heat, without the need for external power supply, achieving the purpose of self-sufficiency.

[0082] To solve the fourth technical problem, the present invention provides the fourth embodiment.

[0083] Embodiment Four

[0084] Please refer to Figure 7, which shows a schematic structural diagram of a 3D packaging heat dissipation system. The system includes multiple chip heat dissipation layers, and each chip heat dissipation layer includes a chip layer 400 and a radiator layer. The radiator layer includes a thermoelectric thin film layer 200, a microscale radiator layer 300, and a micro pump layer 100, wherein the microscale radiator layer 300 and the micro pump layer 100 are connected in communication; the multiple chip heat dissipation layers are connected in communication through an inter-chip bus 800, where: the inter-chip bus is connected to a power supply and is respectively connected in communication with the thermoelectric thin film layer 200, the micro pump layer 100, and the chip layer 400 in each chip heat dissipation layer; the power supply is used to supply power to different micro pump layers 100 and chip layers 400 through the inter-chip bus; the thermoelectric thin film layer 200 is used to supplement the power supply through the inter-chip bus; the micro pump is used to drive the liquid in the micro pump to circulate and dissipate heat in the microscale radiator layer 300 through the voltage provided by the inter-chip bus; the chip layer 400 is used to drive the chips in the chip layer 400 to work through the voltage provided by the inter-chip bus and transmit data to different chip layers 400 through the inter-chip bus.

[0085] Optionally, the inter-chip bus 800 includes a data bus and a power bus. The input of the power bus is respectively connected to the power supply and the thermoelectric thin film layer 200, and the output is respectively connected to the chip layer 400 and the micro pump layer 100. The data bus is used to connect the chip layers 400, enabling data communication between the chips in the multi-layer packaging.

[0086] Preferably, the inter-chip bus 800 is a DC power line carrier communication bus with power supply and data signal transmission functions. The DC power line carrier communication bus loads high-frequency data signals onto the DC power supply signal through the DC power line carrier method, realizing an inter-chip bus that combines data and power supply. Since the frequency of the data signal is different from that of the DC power supply, the loaded data signal can be obtained by filtering at the receiving end of the chip, and modulation and demodulation are relatively easy to implement. Through this DC power line carrier communication bus, not only can the power supply of multiple chips be realized, but also data communication between chips can be achieved. At the same time, the electrical signals generated by the thermoelectric thin film layer 200 can be supplemented to the chips or micro pumps through the DC power line carrier communication bus, realizing multi-layer stacking of chips and recycling of waste heat. All methods using DC power line carrier communication technology to achieve inter-chip communication in the prior art fall within the protection scope of the present invention.

[0087] It should be noted that the relevant technical details of the micro pump in Embodiment 1, the relevant technical details of the thermoelectric thin film layer 200 in Embodiment 2, and the technical details of the chip heat dissipation system in Embodiment 3 are all applicable to Embodiment 4 and will not be elaborated here.

[0088] Among them, the micropump layer 100 has a rated operating power. At the rated operating power, the micropump has a rated delivery flow rate. The DC power line carrier communication bus provides the rated operating power for the micropump. When the electric power generated by the thermoelectric thin film layer 200 is less than the rated operating power of the micropump, the power supply supplements the electric power to the micropump; when the electric power generated by the thermoelectric thin film layer 200 is equal to the rated operating power of the micropump, the heat dissipation system can reach a self-sufficient state; when the electric power generated by the thermoelectric thin film layer 200 is greater than the rated operating power of the micropump, the heat dissipation system can not only reach a self-sufficient state, but also supplement the excess electric power to the power supply for use. If the electric power generated by the thermoelectric thin film layer 200 is directly provided to the micropump layer 100, when the electric power generated by the thermoelectric thin film layer 200 is less than the power consumption of the micropump layer 100, it may cause insufficient power of the micropump; when the electric power generated by the thermoelectric thin film layer 200 is greater than the power consumption of the micropump layer 100, it may cause surplus electric power and waste. The DC power line carrier communication bus can not only collect the electric power generated by the thermoelectric thin film layer 200 to realize waste heat recovery, but also enable the micropump to work stably at the rated operating power.

[0089] As a preferred embodiment, the inter-chip bus includes bumps 810 and through-silicon vias 820 (TSV). Bumps 810 are provided between adjacent layers, and through-silicon vias 820 connecting the upper and lower bumps of each layer are provided in each layer. Among them, the path formed by the through-silicon vias 820 and the bumps 810 is the inter-chip bus 800. The inter-chip bus connects each chip heat dissipation layer, enables the chips in each layer to communicate with each other, collects the electrical signals generated by the thermoelectric thin film layer 200 in each layer, and supplies power to the chips and micropumps in each layer. Optionally, the bumps 810 are solder balls.

[0090] As a preferred embodiment, an interposer 500 is further included in the chip heat dissipation layer. The chip layer 400 is encapsulated on the interposer 500. After the inter-chip bus 800 passes through the chip from the edge of the interposer 500, it passes through the gap between the thermoelectric thin film layer 200 and the microscale heat sink layer 300 and penetrates the micropump layer 100. Among them, the sizes of the microscale heat sink and the thermoelectric thin film are smaller than those of the interposer 500. Therefore, a gap is formed on the vertical plane of the interposer 500 and the microscale heat sink and the thermoelectric thin film. It should be noted that in actual packaging, the sizes of the bumps in different layers are different. Based on the interposer 500 and the inter-chip bus to realize communication and interconnection between layers, higher computing core and storage density can be achieved, and the computing power per unit volume of the chip is stronger.

[0091] As a preferred embodiment, no bumps are provided between the interposer 500 and the micropump layer 100 in the adjacent chip heat dissipation layers, and the through-silicon vias directly pass through the interposer 500 and the micropump layer 100.

[0092] As a preferred embodiment, the inlet and outlet pipes of the microscale radiator layer 300 in each chip heat dissipation layer are communicated. A first inlet and outlet through hole is provided on the packaging substrate 600. The inlet and outlet pipes of the microscale radiator layer 300 pass through the first inlet and outlet through hole. A packaging end blind plug connector is provided at the end of the inlet and outlet pipe extending out of the packaging substrate 600. Preferably, when the system includes an interposer 500, the chip layer 400 is packaged on the interposer 500, and the chip heat dissipation layer includes the interposer 500, the chip layer 400, and the radiator layer arranged in sequence; the interposer 500 is provided with an intermediate inlet and outlet through hole for the inlet and outlet pipe to pass through, and the inlet and outlet pipe passes through the intermediate inlet and outlet through hole.

[0093] As a preferred embodiment, the system further includes a circuit board and an external inlet and outlet pipe. A second inlet and outlet through hole is provided on the circuit board. A board end blind plug connector is provided at the end of the external inlet and outlet pipe extending out of the circuit board through the second inlet and outlet through hole; when the packaging structure is connected to the circuit board, the packaging end blind plug connector is connected to the board end blind plug connector.

[0094] As a preferred embodiment, please refer to Figure 8 , the multiple chip heat dissipation layers share a shared micro pump layer 100, and the shared micro pump layer 100 is arranged at the highest layer of the multiple chip heat dissipation layers; the shared micro pump layer 100 is communicated with the microscale radiator layers 300 in each chip heat dissipation layer through inlet and outlet pipes. That is, there is only one micro pump layer 100 in all chip heat dissipation layers.

[0095] The embodiment of the present invention provides a 3D packaging heat dissipation system, which integrates a chip heat dissipation system. Each layer of chips is configured with a radiator layer, and different layers are communicated through a DC power line carrier communication bus. The radiator layer can not only achieve self-sufficient heat dissipation, but also provide a heat dissipation power of more than 1000 W per square centimeter for each layer, and the DC power line carrier communication bus can supply power to each layer and transmit inter-layer communication signals at the same time, which not only solves the technical problem that high-power chips cannot be 3D packaged due to the low heat dissipation efficiency of the traditional heat dissipation system, but also can realize communication and power supply between chips of different layers.

[0096] Although some specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration and not for limiting the scope of the present invention. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A heat dissipation system for a chip, characterized in that, The system includes a thermoelectric thin film layer, a microscale radiator layer, and a micro pump, where: The thermoelectric thin film layer includes a hot end, a cold end, and a power generation layer. The hot end is connected to the surface of the chip, the cold end is connected to the heat dissipation substrate of the microscale radiator, and the power generation layer is used to form an electromotive force according to the temperature difference between the hot end and the cold end, and output a supply voltage; The microscale radiator layer includes a heat dissipation substrate, and a circulating liquid inlet and a circulating liquid outlet are provided inside the heat dissipation substrate; The micro pump layer is provided with a pump liquid inlet and a pump liquid outlet. The pump liquid inlet is connected to the circulating liquid outlet, and the pump liquid outlet is connected to the circulating liquid inlet; the micro pump layer further includes a piezoelectric component, and the piezoelectric component is connected to the supply voltage and is used to drive the liquid in the micro pump to circulate between the microscale radiator layer and the micro pump layer through voltage.

2. The system according to claim 1, characterized in that, The microscale radiator includes a heat dissipation substrate and heat dissipation fins.

3. The system according to claim 1, characterized in that, A heat dissipation structure is provided in the heat dissipation substrate. The heat dissipation structure includes a heat dissipation cavity, a capillary adsorption structure, and a liquid. The capillary adsorption structure adsorbs the liquid and is arranged on the inner wall of the heat dissipation cavity; the capillary adsorption structure near the cold end of the heat dissipation substrate is the evaporation end, and the capillary adsorption structure far from the evaporation end is the condensation end; when the liquid at the evaporation end absorbs the heat transferred from the cold end, it evaporates into steam, and the steam flows to the condensation end to dissipate heat and condense under the action of the internal pressure difference in the cavity, forming a circulating heat dissipation system.

4. The system according to claim 1, characterized in that, The microscale radiator is a eutectic alloy body or pure silicon, and is integrated into the chip by photolithography.

5. The system according to claim 1, characterized in that, Each chip layer is configured with a thermoelectric thin film layer and a microscale radiator layer.

6. The system according to claim 1, characterized in that, All chip layers share a micro pump layer.

7. The system according to claim 1, characterized in that, A first liquid inlet and outlet through hole is provided on the packaging substrate. The liquid inlet and outlet pipe of the microscale radiator layer passes through the first liquid inlet and outlet through hole, and a packaging end blind plug connector is provided at the end of the liquid inlet and outlet pipe extending out of the packaging substrate.

8. The system according to claim 7, characterized in that, The system further includes a circuit board and an external liquid inlet and outlet pipe. A second liquid inlet and outlet through hole is provided on the circuit board. A board end blind plug connector is provided at the end of the external liquid inlet and outlet pipe extending out of the circuit board through the second liquid inlet and outlet through hole; when the packaging structure is connected to the circuit board, the packaging end blind plug connector is connected to the board end blind plug connector.

9. The system according to claim 8, characterized in that, The first liquid inlet and outlet through hole is drilled by photolithography or a photolithography-like process, and the second liquid inlet and outlet through hole is drilled by a MEMS manufacturing process.

10. The system according to claim 8, characterized in that, The packaging end blind plug connector, the board end blind plug connector, and the external liquid inlet and outlet pipe are mounted on the surface of the PCB by surface mount technology.

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