CN114664768A - A pin-fin and rib combined micro-channel radiator - Google Patents

Abstract

A ribbed pin-fin combined micro-channel radiator, comprising a micro-channel substrate and a cover plate; the micro-channel substrate includes pin fins, rib plates, shunt channels, sub-channels, confluence channels and sidewalls; the pin fins are distributed in Above the hot spot, the rib plates are arranged on the left and right sides of the pin fin, leaving a large area of shunt channels on the upper and lower sides of the pin fin; a confluence channel is arranged between the rib plate and the side wall of the micro channel; the cover plate includes a cooling medium inlet and two cooling medium outlets; the cooling medium inlet is located above the pin fins of the microchannel substrate, and the two cooling medium outlets are located above the confluence channel formed between the rib plate and the side wall. The invention combines the advantages of the strong heat dissipation capability of the pin-fin structure and the small pressure drop of the rib plate micro-channel, effectively controls the temperature rise of the hot spot area under the condition of low pumping power consumption, and makes the temperature of the bottom wall of the radiator relatively low. The temperature uniformity of electronic components is also improved, which is beneficial to prolong the service life of electronic components.

Description

A pin-fin and rib-plate combined micro-channel radiator

technical field

The invention belongs to the technical field of electronic device cooling, and in particular relates to a micro-channel heat sink for solving the problem of chip hot spots.

Background technique

With the continuous development of integrated circuit technology and electronic packaging technology, the power consumption of chip-level devices continues to rise, and the heat flux density increases sharply. In some high-performance electronic components, the heat flux density even reaches 1000W/cm ² . High temperature will reduce the reliability of electronic components and even cause damage to electronic components. The problem of thermal management of electronic equipment has become increasingly prominent. Conventional natural air cooling and forced air cooling can no longer meet the heat dissipation requirements of high-power devices. Therefore, researchers have proposed emerging technologies such as micro heat pipes, vacuum chamber vapor chambers, carbon nanotubes, and microchannels. Among them, the microchannel technology that uses fluid to dissipate heat has been the most widely studied. Microchannel heat sinks were first proposed by Tucherman and Pease in 1981. Compared with conventional radiators, micro-channel radiators have the advantages of large heat exchange area, strong heat exchange capacity and small volume. However, most of the current researches focus on the development of radiators with uniform heat sources, and the heat dissipation of non-uniform heat sources is rarely studied.

In a chip, the heat flux generated in the core area is significantly higher than in other areas of the processor. These areas of high heat flux are called hot spots. Generally speaking, the heat transfer inside the chip to the heat sink is always uneven, and the heat flux in the hot spot area is several times the average heat flux in the background area. The temperature difference caused by the difference in heat flux between the hot spot area and the background area will deform the chip and reduce the life of the chip. Traditional micro-channel heat sinks cannot solve these problems well. Therefore, it is necessary to design a micro-channel heat sink with different heat dissipation capabilities in different regions to reduce the temperature difference in each region of the chip and ensure the reliability of the chip.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a micro-channel radiator combined with pin fins and fins. The combination of fins and pin fins improves the uniformity of temperature distribution and reduces the pumping required for the radiator. The power effectively reduces the local high temperature in the hot spot area, and overcomes the problem that the prior art microchannel cannot solve the problem of the high temperature rise in the hot spot area and the uneven temperature distribution of the cooling wall surface.

The purpose of the present invention is achieved through the following technical solutions.

A rib-plate-pin-fin combined microchannel radiator according to the present invention comprises a microchannel substrate (1) and a cover plate (2).

The microchannel substrate (1) includes pin fins (16), ribs (15), shunt channels (11), sub-channels (12), confluence channels (13) and side walls (14). The pin fins (16) are distributed above the hot spots, the ribs (15) are arranged on the left and right sides of the pin fins (16), and the upper and lower sides of the pin fins (16) leave large-area shunt channels (11). A confluence channel (13) is arranged between the rib plate (15) and the side wall (14) of the microchannel.

The cover plate (2) includes a cooling medium inlet (21) and two cooling medium outlets (22). The cooling medium inlet (21) is located above the pin fins (16) of the microchannel substrate, and the two cooling medium outlets (22) are located in the confluence channel (13) formed between the rib plate (15) and the side wall (14) above.

The cross section of the pin fin (16) according to the present invention can be circular, rectangular, rhombic, triangular, drop-shaped, or airfoil-shaped.

According to the present invention, the ratio of the channel width of the confluence channel (13) to the width of the sub-channels (12) between the ribs is 1:1-5.

The ratio of the width of the rib plate (15) to the width of the sub-channel (12) of the rib plate according to the present invention is 1:1-3.

The ratio of the width of the rib plate (15) to the height of the rib plate according to the present invention is 1:2-5.

The cross-sectional shape of the rib plate (15) according to the present invention can be rectangular, trapezoidal or triangular.

The micro-channel radiator of the present invention is made of silicon, copper, aluminum alloy or other materials with high thermal conductivity, and the pin-fin part and other parts can also be made of different materials.

The pin-fin (16) and rib (15) structures of the present invention are formed by machining or chemical etching.

The cooling process of the present invention is as follows: the cooling medium flows in from the cooling medium inlet (21) located above the pin fins (16), and after impacting the micro-channel pin fins (16) and the bottom wall, it is regenerated by the shunt channel (11). After distribution, it flows into the sub-channels (12) between the rib plates (15), flows through the sub-channels (12) and then reaches the confluence channel (13), and finally flows out from the cooling medium outlet (22) on the cover plate.

Compared with the prior art, the beneficial effects of the present invention are: after the cooling working fluid of the present invention flows through the inlet of the cover plate, it directly impacts the pin fins and the bottom surface of the microchannel above the hot spot area, and the temperature of the cooling working fluid is lower at this time, With the large heat dissipation area of the pin-fin structure, the temperature of the hot spot area is effectively reduced. After flowing out from the pin fins, the cooling medium is redistributed and flows into the gap of the rib plate to continue heat dissipation. After flowing out from the gap of the rib plate, it flows from the side channels on both sides to the outlet on the cover plate. The inlet and outlet modes of the middle inlet and the outlet on both sides adopted in the present invention greatly reduce the flow of the cooling medium in the microchannel, and the overall pressure drop of the radiator is also reduced.

The invention adopts the combination of pin fins and rib plates, and combines the advantages of strong heat dissipation capability of the pin fin structure and small pressure drop in the micro-channels of the rib plates. When the pumping power consumption is small, the temperature rise of the hot spot area is effectively controlled, and the temperature of the bottom wall of the radiator is relatively uniform, and the temperature uniformity of the electronic components is also improved, which is beneficial to prolong the service life of the electronic components.

Description of drawings

FIG. 1 is a schematic exploded view of the structure of the combined pin-fin and rib-plate microchannel heat sink of the present invention.

FIG. 2 is a schematic structural diagram of the substrate of the present invention.

FIG. 3 is a schematic structural diagram of the cover plate of the present invention.

FIG. 4 is a schematic diagram of the heat source distribution on the heat source surface.

FIG. 5 is a comparison diagram of the temperature non-uniformity between the microchannel of the present invention and the heat sink of the rectangular flat microchannel.

FIG. 6 is a comparison diagram of the maximum temperature of the microchannel of the present invention and the heat sink of the rectangular flat microchannel.

FIG. 7 is a comparison diagram of the power consumption of the microchannel of the present invention and the heat sink of the rectangular flat microchannel.

The numbers in the figure are as follows: 1-microchannel substrate, 2-cover plate, 11-split channel, 12-subchannel, 13-confluence channel, 14-side wall, 15-rib, 16-pin fin, 21- Cooling medium inlet, 22-cooling medium outlet.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, only a part of the embodiments of the present invention, but not all of the embodiments, and are not used to limit the present invention.

The main content of the present invention is further explained below in conjunction with the accompanying drawings and specific embodiments, but the content of the present invention is not limited to the following embodiments.

Referring to FIG. 1 , a pin-fin and rib-plate combined micro-channel heat sink for hot spots includes a micro-channel substrate 1 and a cover plate 2 .

In this embodiment, silicon is selected for the microchannel substrate 1, borosilicate glass is selected for the cover plate 2, and the microchannels on the microchannel substrate 1 are directly obtained by etching. The microchannel substrate 1 and the cover plate 2 are hermetically connected by bonding.

Referring to FIG. 2 , the microchannel substrate 1 is 10 mm long, 10 mm wide, and 0.7 mm thick, and the height of the pin fins 16 and the rib plate 15 is 0.5 mm. A pin-fin array is etched above the position of the hot spot, the cross-section of the pin fin is circular, and the size of the distribution area is 2mm*2mm consistent with the size of the hot spot. The diameter of the pin fins is 0.12 mm, and the distance between the pin fins is 0.2 mm. The upper and lower areas of the pin-fin structure leave a large number of blanks as shunt channels. The ribs 15 are arranged on both sides of the microchannel substrate 1, the cross-sectional shape of the ribs is rectangular, and the length of the ribs is 3 mm and the width is 0.25 mm. The ribs 15 are equally spaced, and the distance between the two ribs 15 is 0.25mm. The upper and lower sides of the rib 15 and the side wall 14 of the microchannel substrate are left with a 0.25m wide confluence channel 13 . The side walls of the rib plate and the side walls of the base plate are left with a shunt channel 11 with a width of 0.5 mm.

Referring to FIG. 3 , the cover plate 2 includes a cooling medium inlet 21 and two cooling medium outlets 22 . The cover plate 2 is 10mm long, 10mm wide and 0.2mm thick. The size of the cooling medium inlet 21 is consistent with the size of the pin fin distribution area, which is 2mm*2mm. The cooling medium outlet 22 is respectively located above the confluence channel 13 left by the microchannel rib 15 and the substrate side wall 14 , and has the same length and width as the confluence channel 13 , with a length of 9.25 mm and a width of 0.5 m.

In order to verify the superior performance of the microchannel radiator provided by the present invention in solving the hot spot problem, the traditional rectangular flat microchannel heat dissipation is used as a reference to simulate and compare the two microchannel radiators with ANSYS Fluent software.

Based on this, the detailed thermal simulation calculation model parameters and various boundary conditions are set as follows.

The coolant is deionized water, and the inlet coolant temperature is 300K.

The straight rectangular microchannel is 0.5mm high and 0.25mm wide.

The inlet Reynolds coefficient is determined by the flat rectangular microchannel, and the combined microchannel has the same inlet volume flow rate as the flat rectangular microchannel.

Except for the heat source surface, all other surfaces are thermally insulated.

The material of the radiator substrate is silicon, and the size is 10mm*10mm*0.7mm.

The size of the central heat source area is 2mm*2mm, and the heat flux is 300W/cm ² . The background area heat flux is 50 W/cm ² .

Using the same viscosity model and solution method for the two microchannel radiators, the results shown in Figures 5, 6, and 7 are obtained. The pressure value is obtained by multiplying the average inlet pressure by the total inlet area.

When the inlet Reynolds number of the rectangular flat microchannel radiator is 200, the maximum temperature difference of the cooling surface of the microchannel radiator of the present invention is reduced by 78% compared with the rectangular flat microchannel radiator, the maximum temperature is reduced by 45%, and the pressure drop is reduced by 27% When the inlet Reynolds number of the rectangular flat microchannel radiator is 200, the maximum temperature difference of the cooling surface of the microchannel radiator of the present invention decreases by 65% compared with the rectangular flat microchannel radiator, the maximum temperature decreases by 43%, and the pressure drop increases by 43%. %.

It can be seen from the numerical simulation results that the micro-channel radiator proposed by the present invention has the advantages of stronger heat dissipation capability and better temperature uniformity on the cooling surface compared with the rectangular flat micro-channel radiator in solving the heat dissipation problem with hot spots. Especially when the Reynolds number is small, the pressure drop of the microchannel of the present invention is smaller than that of the rectangular flat microchannel.

Claims (9)

1. A rib-plate and pin-fin combined micro-channel radiator, characterized by comprising a micro-channel substrate (1) and a cover plate (2); the micro-channel substrate (1) includes a pin-fin (16), a rib plate (15), a shunt channel (11), a sub-channel (12), a confluence channel (13) and a side wall (14); the pin fins (16) are distributed over the hot spots, and the ribs (15) are arranged on the pin fins (16) On the left and right sides, the upper and lower sides of the pin fins (16) leave large-area shunt channels (11); a confluence channel (13) is arranged between the rib plate (15) and the side wall (14) of the microchannel; The cover plate (2) includes a cooling medium inlet (21) and two cooling medium outlets (22); the cooling medium inlet (21) is located above the pin fins (16) of the microchannel substrate, and two cooling medium inlets (21) are located above the pin fins (16) of the microchannel substrate. The cooling medium outlet (22) is located above the confluence channel (13) formed between the rib plate (15) and the side wall (14); The cooling medium flows in from the cooling medium inlet (21) located above the pin fins (16), and after impacting the micro-channel pin fins (16) and the bottom wall, it is redistributed by the shunt channel (11) and then flows into the rib plate (15) ) in the sub-channel (12) between ), flow through the sub-channel (12) and then reach the confluence channel (13), and finally flow out from the cooling medium outlet (22) on the cover plate. 2. A ribbed pin-fin combined microchannel radiator according to claim 1, characterized in that the pin-fin (16) section is circular, rectangular, rhombus, triangular, drop-shaped or airfoil-shaped. 3. A rib-pin-fin combined micro-channel radiator according to claim 1, characterized in that the ratio of the channel width of the confluence channel (13) to the width of the sub-channel (12) between the ribs is 1:1- 5. 4. A rib-pin-fin combined micro-channel radiator according to claim 1, characterized in that the ratio of the width of the rib (15) to the width of the sub-channel (12) of the rib is 1:1-3 . 5 . The rib and pin-fin combined type microchannel radiator according to claim 1 , wherein the ratio of the width of the rib ( 15 ) to the height of the rib is 1:2-5. 6 . 6. The rib-pin-fin combined micro-channel radiator according to claim 1, characterized in that the cross-sectional shape of the rib (15) is a rectangle, a trapezoid, or a triangle. 7 . The rib-plate and pin-fin combined micro-channel radiator according to claim 1 , wherein the micro-channel radiator is made of silicon, copper, aluminum alloy or other materials with high thermal conductivity. 8 . 8 . The ribbed pin-fin combined micro-channel heat sink according to claim 1 , wherein the pin-fin part and other parts are made of different materials. 9 . 9 . The ribbed pin-fin combined microchannel radiator according to claim 1 , wherein the pin-fin ( 16 ) and rib ( 15 ) structures are formed by machining or chemical etching. 10 .

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