CN109149325B - A Hybrid Structure Microchannel Heat Sink - Google Patents

Abstract

The invention discloses a microchannel heat sink with a mixed structure, which comprises a heat sink module and a cover plate sealed and connected, the cover plate is located above the heat sink module, and several inlets and outlets arranged at intervals are provided on the cover plate It includes a substrate and a microchannel heat dissipation structure obtained on the substrate by etching or mechanical processing. The microchannel heat dissipation structure includes several parallel fins, and microchannels are formed between the fins. The microchannels and The inlet and outlet are arranged vertically, the fins are provided with a secondary flow channel, and a rectangular fin is arranged between the inlet and the outlet; a large fin corresponding to the inlet is arranged on the base below the inlet, and the length of the large fin is equal to that of the inlet. width. The mixed structure heat sink composed of manifold type, secondary flow channel and rectangular fins of the present invention shortens the flow distance of the cooling liquid in the microchannel, increases the flow space, and enhances the disturbance in the flow process, so that it can At the same time, it enhances heat transfer and reduces pressure loss, and further improves the uniformity of chip temperature.

Description

A Hybrid Structure Microchannel Heat Sink

technical field

The invention relates to the technical field of heat sinks, in particular to a microchannel heat sink with a mixed structure.

Background technique

With the advancement of science and technology, the computing speed of the chip is getting faster and higher, and the integration is getting higher and higher, so more and more heat is generated per unit area. If the heat cannot be taken away in time, the reliability of the chip will be reduced. , the performance will decrease and the life will be shortened.

One of the ways to solve this problem is to take the heat away through the heat sink structure, including air cooling and liquid cooling. Air cooling is suitable for situations where the heat flux density is less than 10W/cm ² , and for high heat flux dissipation requirements, it is necessary to introduce liquid for cooling. In 1981, two scholars in the United States proposed the concept of microchannel liquid cooling. They used a microchannel array heat sink with a width of 50 μm and a height of 320 μm to achieve a high heat flux dissipation requirement of 790W/ ^cm2 , but the required pressure loss was as high as 216kPa, it is difficult to obtain practical application.

For this reason, a large number of scholars have improved and optimized the structure of micro-channel heat sinks, but the existing problems of micro-channel heat sinks are: 1. If you want to achieve a larger heat flux q, the pressure loss ΔP that needs to be paid will be larger Very large; 2. Reasonable pressure loss ΔP, the heat flux q that can be dissipated is very limited; 3. The heat dissipation of the micro-channel heat sink brings the unevenness of the chip temperature, which brings thermal stress, which affects the reliability of the chip , performance, and life are adversely affected.

Contents of the invention

The purpose of the present invention is to provide a microchannel heat sink with a hybrid structure to solve the problems of the above-mentioned prior art. On the one hand, it can reduce the pressure loss and pump work, on the other hand, it can reduce the maximum temperature of the chip surface and improve Uniformity of temperature, which in turn improves chip reliability, performance and lifetime.

To achieve the above object, the present invention provides the following scheme:

The invention provides a microchannel heat sink with a hybrid structure, which includes a heat sink module and a cover plate that are sealed and connected, the cover plate is located above the heat sink module, and several inlets arranged at intervals are arranged on the cover plate and an outlet, the heat sink module includes a substrate and a micro-channel heat dissipation structure obtained on the substrate by etching or machining, the micro-channel heat dissipation structure includes several parallel fins, one of the fins The microchannel is formed between the inlet and the outlet, the microchannel is vertically arranged with the inlet and the outlet, and a secondary flow channel is opened on the rib, and a rectangular rib is arranged in the microchannel between the inlet and the outlet. sheet; the base below the inlet is provided with a large rib corresponding to the inlet, and the length of the large rib is equal to the width of the inlet.

Preferably, there are several rectangular fins uniformly distributed at the outlet of the microchannel.

Preferably, the rectangular ribs in each vertical row are vertically aligned and form a group, and the rectangular ribs are arranged in any number from one to eight groups.

Preferably, the rectangular ribs are replaced with one of parallelogram, rhombus, triangle and wing-shaped ribs.

Preferably, the fins are divided into several trapezoidal fins or parallelogram fins by the secondary flow channel, and the shape of the trapezoidal fins is an isosceles trapezoid.

Preferably, the heat sink module is made of high thermal conductivity material.

Preferably, the high thermal conductivity material is copper or silicon.

Preferably, the width of the inlet is twice the width of the outlet.

Preferably, the substrate is replaced by a silicon plate on the back of the chip.

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

The mixed structure heat sink composed of manifold type, secondary flow channel and rectangular fins of the present invention can shorten the flow distance of cooling liquid in the microchannel through the manifold structure, enhance the mixing of fluid through the secondary flow channel, and increase the The large flow space allows more fluid to flow into the secondary channel through the rectangular fins, thereby enhancing heat transfer and reducing pressure loss at the same time, and improving the temperature uniformity of the chip.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the schematic diagram of the principle of the manifold structure of the hybrid structure microchannel heat sink of the present invention (the secondary runner and the rectangular fin structure are not drawn);

Fig. 2 is the structural representation of the heat sink module of the hybrid structure microchannel heat sink of the present invention;

Fig. 3 is the structure schematic diagram of the hybrid structure microchannel heat sink cover plate of the present invention;

Fig. 4 is the structural representation of the mixed structure microchannel heat sink with triangular fins of the present invention;

Fig. 5 is a structural schematic diagram 1 of the hybrid structure microchannel heat sink of the present invention;

Fig. 6 is the structural schematic diagram II of the hybrid structure microchannel heat sink of the present invention;

Fig. 7 is the structural schematic diagram III of the hybrid structure microchannel heat sink of the present invention;

Among them: 1-base, 2-cover plate, 3-inlet, 4-outlet, 5-microchannel, 6-trapezoidal fin, 7-rectangular fin, 8-triangular fin, 9-large trapezoidal fin, 10 -Secondary runner.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The purpose of the present invention is to provide a micro-channel heat sink with a hybrid structure to solve the problems existing in the prior art, which can simultaneously enhance heat transfer and reduce pressure loss, and improve the uniformity of chip surface temperature, thereby improving the reliability of the chip performance, performance and longevity.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1 to 7: this embodiment provides a microchannel heat sink with a hybrid structure, the heat sink module and the cover plate 2 are sealed and connected, the cover plate 2 is located above the heat sink module, and the cover plate 2 is provided with Several inlets 3 and outlets 4 are provided at intervals, and the heat sink module includes a base 1 and a microchannel heat dissipation structure etched or machined on the base. The heat sink module is made of high thermal conductivity material. The high thermal conductivity material is preferably copper or silicon material. The high thermal conductivity material can also be aluminum or other high thermal conductivity metal alloys and other materials with high thermal conductivity to facilitate heat dissipation. The cover plate 2 is made of low thermal conductivity material, preferably a polymer material, which is convenient for processing and molding.

The cover plate 2 is located above the base 1. Several inlets 3 and outlets 4 are provided on the cover 2 at intervals. In this embodiment, the width of the inlet 3 is twice the width of the outlet 4 . The mixed structure microchannel heat sink in this embodiment is used as one of the units, and its cover plate 2 is provided with one inlet 3 and two outlets 4 , or one outlet 4 and two inlets 3 . The microchannel 5 is used for circulating cooling medium. Wherein, the cooling medium can be water, HFE-7100, Freon and other liquids, and can also be gaseous medium such as air or nitrogen. One end of the cover plate 2 is provided with an inlet hole and an outlet hole for the cooling medium, which facilitates replacement or recycling of the cooling medium.

The substrate 1 is provided with several ribs arranged in parallel, and the microchannel 5 is formed between the ribs. The microchannel 5 in this embodiment is vertically arranged with the inlet 3 and the outlet 4, wherein the microchannel 5 is connected with the inlet 3 and the outlet 4 It can also be arranged to intersect, and the included angle is not limited to 90°, and can be any angle. Wherein, the inlet 3 and the outlet 4 are adjacently designed, which can reduce the flow distance and pressure loss of the cooling medium in the microchannel 5 .

The base 1 below the inlet 3 is provided with a large trapezoidal rib 9 matching the trapezoidal rib 6 , and the length of the long base of the large trapezoidal rib 9 is equal to the width of the inlet 3 . A secondary flow channel 10 is opened on the fin, and the fin is divided into several trapezoidal fins 6 or parallelogram fins by the secondary flow channel 10 . Wherein, the shape of the trapezoidal ribs 6 is preferably an isosceles trapezoid. The secondary flow channel 10 formed by the gap between adjacent trapezoidal fins 6 can enhance the turbulence in the flow process of the cooling medium, thereby enhancing heat exchange, and the secondary flow channel 10 increases the flow space, and to a certain extent can also Reduce pressure loss.

Rectangular ribs 7 are arranged in the microchannel 5 between the inlet 3 and the outlet 4 . The rectangular fins 7 of the mixed-structure microchannel heat sink in this embodiment are evenly distributed at both ends of the microchannel 5 . The rectangular fins 7 can be replaced by one of parallelogram fins, rhombus fins, triangular fins 8 and wing-shaped fins. Wherein, the rectangular fins 7 can be evenly arranged on both sides of the inlet 3, or can be arranged non-uniformly on both sides of the inlet 3, so that more cooling medium flows into the flow channel to further enhance heat exchange. In this embodiment, there are eight sets of uniformly arranged rectangular fins 7, which can allow more cooling medium to flow into the microchannel 5, further enhancing heat exchange. Rectangular fins 7 can also be arranged non-uniformly on both sides of the inlet 3. When non-uniformly arranged, any number of groups can be set according to the number of trapezoidal fins 6 to improve the temperature uniformity of the heat source and reduce thermal stress.

There are several rectangular fins 7 uniformly distributed at the exit 4 of the microchannel 5 . The rectangular ribs 7 can also be arranged in a non-uniform distribution as shown in FIG. 2 . Each vertical rectangular fin 7 is vertically aligned and is one group, and the rectangular fins 7 are preferably arranged in three groups, five groups or eight groups, and can also be arranged according to the length of the microchannel 5 and heat dissipation requirements (more than eight groups) any number of groups.

Numerical simulations were carried out on three types of heat sinks with different numbers of rectangular fin 7 structures, and it was found that the maximum temperature T _max of the chip (heat source) of the three heat sink structures was basically the same, but the pressure loss ΔP of the structure No. 3 was 16388Pa, which was only The 53.2% of the No. 1 structure 30782Pa reduces the pressure drop by 46.8%, but does not increase the maximum temperature of the chip (heat source), that is, does not increase the total thermal resistance of the heat sink. Therefore, during use, an appropriate number of 7 sets of rectangular fins can be selected according to the use environment to meet heat dissipation requirements.

Grouping (number of groups of rectangular fin structures) T_max(K) ΔP(Pa) No. 1 (eight groups) 327.92 30782 No. 2 (group of five) 327.87 22261 Number three (three groups) 328.04 16388

Table 1 Simulation data table of three heat sink structures with different numbers of rectangular fin groups

The mixed-structure microchannel heat sink in this embodiment can be adhering or embedded. The bonding type refers to processing the microchannel 5 with a mixed structure on a high thermal conductivity material, and then using a high thermal conductivity adhesive to paste the base 1 of the heat sink module and the back of the chip together. Embedded means that the microchannel 5 and the secondary flow channel 10 are directly etched on the silicon plate on the back of the chip, and then the cover plate 2 is sealed and bonded to it. The silicon plate on the back of the chip is directly used as the base 1 of the heat sink module. Then the chip is directly cooled by the flow of the cooling medium.

The working process and principle of the present embodiment are as follows:

The cooling medium is introduced from the inlet in the cover plate 2 to the inlet 3 in the cover plate 2, and then flows into the microchannel 5 under the cover plate 2, and then the cooling medium passes through the flow channel formed by the trapezoidal fins 6 and the rectangular fins 7 It flows toward the outlets on both sides until it flows out from the outlets 4 at both ends of the cover plate 2, and then flows to the outlet for replacement or recycling of the cooling medium. Among them, the flow channel structure of the cover plate 2 with an outlet 4 on both sides adjacent to the inlet 3 shortens the flow distance of the cooling medium in the flow channel, thereby greatly reducing the pressure loss; the original long straight fins are cut into The trapezoidal fins 6 or parallelogram fins are arranged in rows one by one, and secondary flow channels 10 are formed between the trapezoidal fins 6 or parallelogram fins, and the cooling medium in the main flow area can flow into these secondary flow channels 10, thereby The turbulence of the cooling liquid is enhanced, and the heat exchange is enhanced; adding rectangular fins 7 near the outlet 4 can slow down the flow velocity of the cooling medium, so that more cooling medium flows into the secondary flow channel 10 to further enhance the heat exchange.

In this description, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention; meanwhile, for those of ordinary skill in the art, according to this The idea of the invention will have changes in the specific implementation and scope of application. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (9)

1. A hybrid structure micro-channel heat sink, characterized in that: comprise a heat sink module and a cover plate that are sealed and connected, the cover plate is positioned above the heat sink module, and the cover plate is provided with several intervals The inlet and outlet of the heat sink module include a substrate and a microchannel heat dissipation structure obtained on the substrate by etching or mechanical processing. The microchannel heat dissipation structure includes several parallel ribs, and the parallel Micro-channels are formed between the set ribs, and the micro-channels are arranged perpendicular to the inlet and the outlet, and secondary flow channels are opened on the parallel ribs, and the lower base between the inlet and the outlet Rectangular ribs are arranged in the microchannel on the top; a large rib corresponding to the inlet is arranged on the base below the inlet, and the length of the big rib is equal to the width of the inlet. 2 . The microchannel heat sink with a hybrid structure according to claim 1 , wherein there are several rectangular fins uniformly distributed at the outlet of the microchannel. 3 . 3. The microchannel heat sink with hybrid structure according to claim 2, characterized in that: the rectangular fins in each vertical column are vertically aligned and form one group, and the rectangular fins are arranged in any number of one to eight groups . 4. The microchannel heat sink with hybrid structure according to claim 3, characterized in that: the rectangular fins are replaced by one of parallelogram, rhombus, triangle and wing-shaped fins. 5. The microchannel heat sink with hybrid structure according to claim 1, characterized in that: the parallel fins are divided into several trapezoidal fins or parallelogram fins by the secondary flow channel, and the trapezoidal fins The shape of the ribs is an isosceles trapezoid. 6. The microchannel heat sink with hybrid structure according to claim 1, characterized in that: the heat sink module is made of high thermal conductivity material. 7. The microchannel heat sink with hybrid structure according to claim 6, characterized in that: the high thermal conductivity material is copper or silicon material. 8. The microchannel heat sink with hybrid structure according to claim 1, wherein the width of a single inlet is twice the width of a single outlet. 9. The hybrid structure microchannel heat sink according to any one of claims 1-8, characterized in that: the substrate is replaced by a silicon plate on the back of the chip.