CN105118811A - Temperature equalizing device adopting vapor chamber and microchannel for radiating multi-heat-source device - Google Patents

Abstract

The invention discloses a temperature equalizing device for dissipating heat from multiple heat source devices by adopting a soaking plate and microchannels, which is used to solve the problem that existing heat dissipating devices cannot uniformly dissipate heat from multiple heat sources and high heat flux density electronic devices, and the current The temperature of some parallel microchannels rises rapidly along the flow direction during use, forming a large temperature gradient and affecting the stability of the chip. The present invention includes an LTCC substrate, at least two heat sources are packaged in the LTCC substrate, a vapor chamber is installed above the LTCC substrate, microchannels having the same number as the heat sources are arranged above the vapor chamber, and each microchannel The inlet of each microchannel communicates with the external cooling liquid source through an inlet, and the outlet of each microchannel communicates with the external liquid collection tank.

Description

A temperature equalizing device for dissipating heat from multi-heat source devices using a soaking plate and microchannels

technical field

The invention belongs to the technical field of heat dissipation devices based on LTCC multi-chip components, and specifically discloses a temperature equalization device that uses a soaking plate and microchannels to dissipate heat from multiple heat source devices, and is used for dissipating heat from devices with multiple heat sources and high heat flux density.

Background technique

Modern microelectronic chip technology is developing rapidly. Multi-chip module (MCM) is a microelectronic packaging technology developed on the basis of hybrid integrated circuits, which has more functions, higher performance and smaller volume. Ceramic multi-chip component (MCM-C), as an advanced stage of thick film HIC development and a practical multi-chip component, has many significant advantages such as many interconnection layers, high integration density, excellent electrical performance, and low manufacturing cost. more and more widely used. The high-performance packaging of LTCC-type MCM-C is effectively realized by integrating the low-temperature co-fired ceramic (LTCC) substrate, the cavity wall of the package shell, and the PGA outer leads. With the continuous reduction of chip size and the increase of the number and power of integrated circuit packaging components, the heat flux density of the entire microelectronic system has increased sharply, resulting in a gradual increase in the operating temperature of electronic devices. Research has found that the increase in component temperature is not good for the long-term use of equipment, and semiconductor components are very sensitive to temperature. According to the famous "10°C rule", every time the operating temperature of an electronic component rises by 10°C, the service life of the component will be reduced by half ; In the working environment of 70 ℃ to 80 ℃, the reliability of components will decrease by 5% for every 1 ℃ rise in temperature; therefore, it is extremely important to control the temperature of high heat flux electronic devices.

In the current research field of electronic heat dissipation, common heat dissipation methods include air cooling, liquid cooling and phase change cooling. Since when the heat dissipation density is greater than 5, the air cooling method cannot meet the heat dissipation requirements, and liquid cooling should be used. cooling method. Microchannel heat sink is a liquid cooling device that is widely used at present. Microchannel heat sink mainly takes away heat by forced convection. Under the condition of high heat flux, due to the large temperature difference between the inlet and outlet of microchannel heat sink, it is easy to cause The temperature of the electronic devices near the outlet is significantly higher than that of the electronic devices near the inlet. Therefore, under the condition of high heat flux, a phase-change heat device should be used for heat exchange.

After the phase change of the liquid working medium on the evaporation surface of the phase change heat device (soaking plate) is heated, the steam moves along the axial direction of the soaking plate to the condensation surface, where the phase change and condensation occur on the condensation surface, and the condensed liquid working medium is in the structure of the liquid absorbing core. Driven by capillary pressure and gravity, it flows back along the radial direction of the vapor chamber, and the condensed liquid can also flow back to the evaporation surface from the axial direction through the support column. The heat transfer mode of the heat pipe is one-dimensional, which is the conduction mode of the line, while the steam of the vapor chamber can condense on the entire condensation surface, and the conduction mode is two-dimensional, which is the conduction mode of the surface, so the vapor chamber Heat transfer efficiency and temperature uniformity are better than traditional heat pipes. For example, Invention Zhuanla with application number 201210187939.4 discloses a phase change heat dissipation device for dissipating heat from heating elements. It includes a cavity and a working medium arranged in the cavity. The insulating material is changed, and the cavity accommodates heating elements; the working medium is crystalline hydrated salts, organic acids or esters, etc.

However, for electronic devices with multiple heat sources and high heat flux density, due to the different powers of the components when they work normally, the calorific value of each component in the multi-chip module is also different. In the prior art, uniform and parallel micro-channels are used for heat dissipation. If Using a uniform flow channel structure for heat dissipation will result in inconsistent temperatures of each heat source. Therefore, research on heat dissipation of electronic devices with multiple heat sources and high heat flux has great research value.

Contents of the invention

In order to solve the problem that the existing heat dissipation device cannot uniformly dissipate heat from electronic devices with high heat flux density of multiple heat sources, and the temperature of the existing parallel microchannel rises rapidly along the flow direction during use, a large temperature gradient is formed In order to solve the problem of affecting the stability of the chip, we provide a temperature equalizing device that uses a vapor chamber and microchannels to dissipate heat from multiple heat source devices. The vapor chamber in a two-dimensional heat transfer mode is used for heat dissipation, and has a lower thermal resistance value. , the heat dissipation speed of the chip is faster; at the same time, the microchannel design of the present invention can reduce the temperature gradient, realize the uniform distribution of heat, and avoid the damage caused by the excessive local heat load of the chip; pressure drop.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A temperature equalizing device that uses a vapor chamber and microchannels to dissipate heat from multiple heat source devices, characterized in that it includes an LTCC substrate, at least two heat sources are packaged in the LTCC substrate, and a vapor chamber is installed above the LTCC substrate , the top of the vapor chamber is provided with the same number of micro-channels as the number of heat sources, the inlet of each micro-channel communicates with an external cooling liquid source through an inlet, and the outlet of each micro-channel communicates with an external liquid collection tank.

The number of flow channels of each microchannel is the same or different.

Each flow channel of the microchannel is arranged side by side with each other.

The vapor chamber includes a metal shell, which forms a steam chamber. The inner wall of the metal shell is provided with a liquid-absorbing core, and the steam chamber is filled with working liquid. The metal shell is also provided with a vertical A supporting column is provided, and the upper and lower ends of the supporting column are respectively connected to the liquid-absorbing core.

The support column is a cylinder.

The liquid-absorbing core is a sintered metal powder liquid-absorbing core.

A capillary layer is provided on the surface of the support column, and the capillary layer is made of sintered metal powder.

An insulating heat conducting plate is provided between the vapor chamber and the LTCC substrate.

Compared with the prior art, the present invention has the following beneficial effects:

The temperature equalizing device of the present invention adopts a vapor chamber and a microchannel to dissipate heat from a multi-heat source device, comprising an LTCC substrate, at least two heat sources are packaged in the LTCC substrate, a vapor chamber is installed above the LTCC substrate, and the Microchannels with the same number as the heat source are arranged above the vapor chamber, and the inlet of each microchannel is connected with an external cooling liquid source through an inlet, and the outlet of each microchannel is connected with an external liquid collection tank. The present invention adopts a two-dimensional heat transfer vapor chamber to dissipate heat, which has lower thermal resistance, faster chip heat dissipation, and uniform heat transfer; at the same time, each microchannel of the present invention is connected together to form a Y-shaped structure, which can be used for uniform heat dissipation of multi-heat source devices. Compared with traditional parallel microchannels, it can reduce the temperature gradient and achieve uniform heat distribution, avoiding the damage caused by excessive local heat load of the chip; microchannels also reduce The total pressure drop of the entire microchannel is reduced. Reducing the total pressure drop can reduce the impact of the inlet and outlet of the microchannel, ensure the sealing performance of the inlet and outlet, reduce the impact on the wall of the flow channel, and prolong the service life of the microchannel.

Description of drawings

Fig. 1 is an explosion schematic diagram of an embodiment of the present invention;

Fig. 2 is a sectional view structural representation of the present invention;

Fig. 3 is the structural representation of the second microchannel among Fig. 1;

Fig. 4 is the structural representation of the first microchannel among Fig. 1;

Fig. 5 is a schematic cross-sectional view of the vapor chamber in Fig. 1 when in use;

Fig. 6 is a structural block diagram of the present invention in use.

Marks in the figure: 1. Microchannel cover plate, 2. First microchannel, 3. Vapor chamber, 4. Insulated heat conducting plate, 5. LTCC substrate, 6. First heat source, 7. Second heat source, 8. Second heat source Two microchannels, 9. Metal shell, 10. Liquid-absorbing core, 11. Steam chamber, 12. Support column.

Detailed ways

The present invention will be further described below in conjunction with the embodiments, and the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other used embodiments obtained by persons of ordinary skill in the art without creative efforts all belong to the protection scope of the present invention.

In conjunction with the accompanying drawings, the temperature equalizing device of the present invention that adopts a vapor chamber and a microchannel to dissipate heat to a multi-heat source device includes an LTCC substrate 5, and at least two heat sources are packaged in the LTCC substrate 5 (for example, the first marked in Fig. 1 heat source 6, second heat source 7), the LTCC substrate 5 of the present invention can package a plurality of heat sources according to the actual use situation; the top of the LTCC substrate 5 is installed with a vapor chamber 3, and There are the same microchannels as the number of heat sources (the first microchannel 2 and the second microchannel 8 marked in Figure 1), for the convenience of installation and use, the microchannels are equipped with microchannel cover plates 1; each microchannel The inlet is communicated with an external cooling liquid source through an inlet, and the outlets of each microchannel are communicated with an external liquid collection tank. The present invention adopts a two-dimensional heat transfer vapor chamber to dissipate heat, which has lower thermal resistance, faster chip heat dissipation, and uniform heat transfer; at the same time, each microchannel of the present invention is connected together to form a Y-shaped structure, which can be used for uniform heat dissipation of multi-heat source devices. Compared with traditional parallel microchannels, it can reduce the temperature gradient and achieve uniform heat distribution, avoiding the damage caused by excessive local heat load of the chip; microchannels also reduce The total pressure drop of the entire microchannel is reduced. Reducing the total pressure drop can reduce the impact of the inlet and outlet of the microchannel, ensure the sealing performance of the inlet and outlet, reduce the impact on the wall of the flow channel, and prolong the service life of the microchannel.

Referring to Fig. 1, Fig. 3 and Fig. 4, each channel of the present invention forms a Y-shaped structure, and a certain pressure rise is generated at each bifurcation, thereby reducing the total pressure drop of the entire channel.

The number of runners of each microchannel is the same or different. In actual use, the power of the heat source is largely different. Therefore, the number of runners of the microchannel is selected according to the power of the heat source. For example, the power of the second heat source 7 of the present invention is 60w , then the corresponding second microchannel 8 selects the microchannel of 6 runners for use, and the power of the first heat source of the present invention is 80w, so the first microchannel 2 corresponding to it selects the microchannel of 8 runners for use aisle.

As a preferred mode of the present invention, the length and width of the first microchannel and the second microchannel are 30mm × 30mm, the height of the flow channel is 2mm, and the width of the flow channel is 2.5mm. The flow of the second microchannel 8 The channel pitch is 2.5 mm, and the flow channel pitch of the first microchannel 2 is 1.25 mm.

Referring to Fig. 5, the vapor chamber 3 of the present invention includes a metal shell 9, the metal shell 9 forms a steam chamber 11, and the inner wall of the metal shell 9 is provided with a liquid-absorbing core 10, and the steam chamber 11 is filled with working liquid, the metal shell 9 is also provided with a vertical support column 12, and the upper and lower ends of the support column 12 are respectively connected to the liquid-absorbing core 10. The working principle of the vapor chamber of the present invention is as follows: for the convenience of description, the end in contact with the heat source is called the evaporation surface, and the end in contact with the microchannel is called the condensation surface; the heat of the heat source enters the metal shell from the outside, and the evaporation surface works in a liquid state After the liquid is heated and undergoes a phase change, the steam moves to the condensation surface along the axial direction of the vapor chamber, where it undergoes a phase change and condenses. The working liquid can also flow back from the axial direction to the evaporation surface through the support to complete a heat transfer cycle and form a two-phase circulation system in which liquid and gas coexist, so a steam with good temperature uniformity can be formed on the surface of the vapor chamber Condensation can occur on the entire condensation surface, and the conduction mode is two-dimensional, which is the surface conduction mode; the steam chamber is always filled with saturated steam at the same temperature, so the heat transfer efficiency and temperature uniformity of the vapor chamber are better than traditional heat pipes.

As a preferred mode of the present invention, the support column is a cylinder with a diameter of 4mm, which supports the horizontal and vertical arrangements evenly, the horizontal spacing is 16mm, the longitudinal spacing is 18mm, and the horizontal spacing of the supporting columns 12 is not greater than 40mm. , the vertical arrangement is not less than two rows, and it is arranged at equal intervals in the horizontal and vertical directions; the liquid-absorbing core is a sintered metal powder liquid-absorbing core; the surface of the support column is provided with a capillary layer, and the thickness of the capillary layer is 2mm. Made of sintered metal powder. The heat transfer efficiency is further improved by using the metal powder layer as the capillary layer to reduce the return path of the condensed working liquid.

As a preferred mode of the present invention, an insulating and heat-conducting plate 4 is provided between the vapor chamber 3 and the LTCC substrate 5 .

The microchannel and the soaking plate of the present invention are packaged in the same casing, which can reduce thermal resistance and improve heat dissipation effect.

Combined with Figure 6, it is a structural block diagram of the present invention in use, which forms a heat dissipation system with external equipment, mainly including a liquid supply tank, a liquid collection tank, a flow controller, a computer, a temperature tester, a pressure drop tester and pipelines Composition, the working process is: first set the corresponding data in the debugging controller through data programming, and then the speed controller controls the water pump motor to obtain the corresponding flow from the liquid supply tank, and deliver it to each microchannel from the same inlet , the liquid after heat exchange in the microchannel finally enters the liquid collection tank for cooling; both ends of the microchannel are connected in parallel with a pressure drop tester to measure the pressure drop, and the bottom of the microchannel is a vapor chamber, which drives the condensation surface of the vapor chamber The heat makes the soaking plate cool down rapidly. The heat source under the soaking plate can provide a constant heat flux density, and can also detect the temperature of the bottom surface of the microchannel, that is, it integrates a heat source and a temperature tester.

Embodiment one

The temperature equalizing device of this embodiment adopts a vapor chamber and a microchannel to dissipate heat from a multi-heat source device, including an LTCC substrate, at least two heat sources are packaged in the LTCC substrate, and a vapor chamber is installed above the LTCC substrate, so that Microchannels with the same number as the heat source are arranged above the vapor chamber, the inlet of each microchannel communicates with an external cooling liquid source through an inlet, and the outlet of each microchannel communicates with an external liquid collection tank.

Embodiment two

The temperature equalizing device of this embodiment adopts a vapor chamber and a microchannel to dissipate heat from a multi-heat source device, including an LTCC substrate, at least two heat sources are packaged in the LTCC substrate, and a vapor chamber is installed above the LTCC substrate, so that The top of the vapor chamber is provided with the same number of micro-channels as the number of heat sources, the inlet of each micro-channel communicates with an external cooling liquid source through an inlet, and the outlet of each micro-channel communicates with an external liquid collection tank; The channels have the same or different number of runners.

Embodiment three

The temperature equalizing device of this embodiment adopts a vapor chamber and a microchannel to dissipate heat from a multi-heat source device, including an LTCC substrate, at least two heat sources are packaged in the LTCC substrate, and a vapor chamber is installed above the LTCC substrate, so that The top of the vapor chamber is provided with the same number of micro-channels as the number of heat sources, the inlet of each micro-channel communicates with an external cooling liquid source through an inlet, and the outlet of each micro-channel communicates with an external liquid collection tank; The channels have the same or different numbers of channels; the channels of the microchannels are arranged side by side.

Embodiment four

On the basis of any of the above-mentioned embodiments, the vapor chamber includes a metal shell, the metal shell forms a steam chamber, and a liquid-absorbing core is arranged on the inner wall of the metal shell, and the working liquid is injected into the steam chamber , the metal shell is also provided with a vertical support column, and the upper and lower ends of the support column are respectively connected to the liquid-absorbing core.

Embodiment five

On the basis of Embodiment 4, the support column is a cylinder.

Embodiment six

On the basis of Embodiment 4 or Embodiment 5, the liquid-absorbing core is a sintered metal powder liquid-absorbing core.

Embodiment seven

On the basis of any one of Embodiment 4 to Embodiment 6, a capillary layer is provided on the surface of the support column, and the capillary layer is made of sintered metal powder.

Embodiment eight

On the basis of any of the above-mentioned embodiments, an insulating and heat-conducting plate is provided between the vapor chamber and the LTCC substrate.

Claims (8)

1. A temperature equalizing device that adopts vapor chamber and microchannel to dissipate heat to multi-heat source devices, is characterized in that, comprises LTCC substrate, at least two heat sources are packaged in the described LTCC substrate, and a thermostat is installed above the described LTCC substrate. A hot plate, the microchannels with the same number as the heat source are arranged above the vapor chamber, the inlet of each microchannel is connected with the external cooling liquid source through an inlet, and the outlet of each microchannel is connected with the external liquid collection tank. 2 . The temperature equalizing device for dissipating heat from multiple heat source devices using a vapor chamber and microchannels according to claim 1 , wherein the number of flow channels of each of the microchannels is the same or different. 3 . 3 . The temperature equalizing device for dissipating heat from multiple heat source devices using a vapor chamber and microchannels according to claim 2 , wherein each flow channel of the microchannels is arranged side by side with each other. 4 . 4. The temperature equalizing device adopting a vapor chamber and a microchannel to dissipate heat to multi-heat source devices according to claim 1, wherein the vapor chamber comprises a metal shell, the metal shell forms a steam chamber, and the metal shell The inner wall of the body is provided with a liquid-absorbing core, the steam chamber is injected with working liquid, and the metal shell is also provided with a vertical support column, and the upper and lower ends of the support column are respectively connected to the liquid-absorbent core. 5 . The temperature equalizing device for dissipating heat from multiple heat source devices using a vapor chamber and microchannels according to claim 4 , wherein the support column is a cylinder. 5 . 6 . The temperature equalizing device for dissipating heat from multiple heat source devices using a vapor chamber and microchannels according to claim 4 , wherein the liquid-absorbing core is a sintered metal powder liquid-absorbing core. 7 . 7. The temperature equalizing device adopting vapor chamber and microchannel to dissipate heat to multi-heat source devices according to claim 5, characterized in that, the surface of the support column is provided with a capillary layer, and the capillary layer is made of sintered metal powder become. 8. The temperature equalizing device for dissipating heat from multiple heat source devices using a vapor chamber and microchannels according to any one of claims 1-7, characterized in that an insulating heat conducting plate is provided between the vapor chamber and the LTCC substrate.