CN116504736A - Micro-channel heat dissipation device for high heat flux chip package - Google Patents

Abstract

The invention discloses a micro-channel heat dissipation device for packaging a high-power high-heat-flux chip. One end of the micropump is connected with the cooling working medium inlet, the other end of the micropump is connected with the liquid storage tank, the cooling working medium flows through the heat-dissipating functional chip from the inlet under the action of the micropump, and then flows back to the liquid storage tank outside the chip through the isothermal processor, so that a fluid loop of the cooling working medium is formed. The micro-channel heat radiation structure is etched at the lower half part of the functional chip, the functional chip is connected with an external water-cooling heat radiation plate through silicone grease so as to further absorb heat generated by the work of the chip, the water-cooling heat radiation plate is fixed above the functional chip, and the flow rate of the water-cooling heat radiation plate is controlled through an external pump so as to realize the control of the working temperature of the functional chip. The temperature sensor is arranged on the upper surface of the water cooling plate and the lower surface of the water cooling plate to obtain the temperature difference of the upper surface and the lower surface of the water cooling plate. Real-time data of the working temperature of the functional chip is obtained through the temperature sensor, the working states of the micro-channel heat dissipation structure and the water cooling heat dissipation plate are controlled, and effective heat management of the device packages with different power and different heat flux density is achieved.

Description

A microchannel cooling device for high heat flux density chip packaging

technical field

The invention relates to the field of microchannel heat dissipation and cooling of electronic components with high heat flux density, in particular to a microchannel heat dissipation device used for high heat flux density chip packaging.

Background technique

Since the pioneering work of Tuckerman and Pease in the early 1980s, microchannel heat sinks containing single-phase liquid flow have been widely used in various high heat flux device applications as one of the most promising technologies for efficient heat transfer . With the rapid development of ultra-large-scale integrated circuits (ULSIC), due to the improvement of processing speed and the demand for miniaturization, the heat flow on the surface of the chip has greatly increased. In order to further improve the heat dissipation performance of the chip to keep the device in service within its allowable temperature, Among them, microchannel heat sinks with passive microstructures are considered to be an effective means to meet this demand. The advantages of the new microchannel heat sink structure in thermal and frictional characteristics have been widely used in the field of heat transfer.

From the published literature, it is found that when the Reynolds number in the flow channel is lower than 350, the performance of the microchannel heat sink with the front triangle offset rib in the micro channel is the best, and when the Reynolds number in the flow channel is higher than 400 , the microchannel heat sink with semicircular offset ribs inside the microchannel performed best. In order to obtain better flow characteristics and heat transfer characteristics within a limited package volume, a systematic and detailed study of such microchannel heat sinks, the present invention focuses on the geometries with aligned and offset scalloped ribs within the microchannel Influence on flow and heat transfer characteristics. The present invention optimizes the heat transfer performance of the microchannel cooling device from the parameters of the width, height and spacing of fan-shaped ribs in the microchannel, and the heat transfer performance focuses on the temperature uniformity, maximum temperature characteristics and pressure drop loss in the microchannel cooling device.

Contents of the invention

The object of the present invention is to provide a micro-channel heat dissipation device for packaging high-power and high-heat-flux devices, so as to solve the defects in the prior art.

In order to achieve the above object, the present invention provides a microchannel cooling device for packaging high-power and high-heat-flux devices, including a water-cooled cooling plate, a micropump, a microchannel cooling structure, a built-in temperature sensor and a functional chip. One end of the micropump is connected to the inlet of the cooling medium and the other end is connected to the liquid storage pool. Under the action of the micropump, the cooling medium flows from the inlet through the heat-dissipated function chip, and then flows back to the liquid storage pool through the isothermal processor outside the chip to form a cooling process. quality fluid circuit. The micro-channel heat dissipation structure is etched on the lower half of the functional chip. The functional chip is connected to the external water-cooled heat sink through silicone grease to further absorb the heat generated by the chip. The water-cooled heat sink is fixed above the functional chip and controlled by an external pump. The flow rate is to realize the working temperature control of the functional chip. The temperature sensor is arranged on the upper surface of the water-cooled heat sink and the lower surface of the water-cooled heat sink to obtain the temperature difference between the upper and lower surfaces of the water-cooled heat sink. Obtain real-time data of the working temperature of the functional chip through the temperature sensor, control the working state of the micro-channel heat dissipation structure and the water-cooled heat dissipation plate, and realize effective thermal management of device packages with different powers and different heat flux densities. Research data show that the invention can meet the heat dissipation requirement of a chip with a heat flux density of 300w/cm ² .

Preferably, the microchannel heat dissipation structure contains fins inside, and the arrangement density of the fins near the inlet of the cooling working medium is smaller than the arrangement density of the fins near the outlet of the cooling working medium.

Preferably, the micro pump is a micro water pump with controllable pumping flow.

Preferably, the micro-channel heat dissipation structure is placed in the lower half of the functional chip, and the micro-channel heat dissipation structure uses an etching process to complete the manufacture of the internal micro-channel, and is directly integrated on the functional chip.

Preferably, the microchannel includes a cavity structure and a protrusion structure, and the arrangement density of the protrusion structures near the cooling working medium inlet is smaller than the arrangement density of the protrusion structures near the cooling working medium outlet, and the arrangement density of the protrusion structures near the cooling working medium inlet is The arrangement height of the protrusion structures is greater than the arrangement height of the protrusion structures near the outlet of the cooling working medium.

Preferably, the protruding structures include isosceles triangular protruding structures, arc-shaped protruding structures, trapezoidal protruding structures and zigzag protruding structures, isosceles triangular cave structures, arc-shaped cave structures, trapezoidal cave structures and zigzag cave structures.

The present invention has the following beneficial effects:

1. The present invention adopts a multi-stage water-cooled heat dissipation method, and adopts different methods to dissipate heat for chips under different working powers, so as to ensure the best heat dissipation effect and realize the optimal heat dissipation effect in a limited space.

2. The water cooling of the present invention adopts micro-channels to dissipate heat, the channels of the water-cooling heat dissipation plate are evenly arranged, and the water flow in the channels is opposite to the direction of the water flow in the micro-channels, so that the heat dissipation performance is further improved.

The present invention will be described in further detail below with reference to the accompanying drawings.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 is a kind of microchannel cooling device structure schematic diagram that is used for high power high heat flux device packaging of the preferred embodiment of the present invention;

Fig. 2 is a schematic diagram of an exploded structure of a microchannel heat sink for high power and high heat flux device packaging according to a preferred embodiment of the present invention;

Fig. 3 is a half-sectional view of a microchannel cooling device for high-power and high-heat-flux device packaging according to a preferred embodiment of the present invention;

Fig. 4 is a schematic diagram of a microchannel heat dissipation structure of a microchannel heat dissipation device for high power and high heat flux device packaging according to a preferred embodiment of the present invention;

Fig. 5 is a partial enlarged view of the microchannel heat sink of a microchannel heat sink for high power and high heat flux device packaging according to a preferred embodiment of the present invention;

Fig. 6 is a partial comparison diagram of a microchannel heat dissipation device for high power and high heat flux device packaging and other four microchannel heat dissipation structures of a preferred example of the present invention;

In the figure, 1. PCB board; 2. Microchannel structure; 3. Temperature sensor; 4. Water cooling plate channel; 5. Micro pump; 9. Water-cooled heat dissipation plate; 10. Silicon plate; 11. Micro-channel heat dissipation structure; 12. Silicon grease; 13. Functional chip; 14. Cooling medium return inlet of the micro-channel heat dissipation plate; 15. Cooling medium return outlet of water-cooled heat dissipation plate; 16. Chip pins; 17. Upper contact piece of temperature sensor; 18. Downward transmission contact piece of temperature sensor; 19. Coolant flow inlet of water-cooled heat dissipation plate; 20. Water-cooled heat dissipation plate Cooling medium outlet; 21. Cooling medium inlet of microchannel heat dissipation structure; 22. Microchannel heat dissipation structure cooling medium outlet; 23. Water storage pool; 24. Cooling medium outlet; 25. Cooling medium inlet; 201 . Isosceles triangular cavity structure; 211. Arc-shaped cavity structure; 221. Isosceles trapezoidal cavity structure; 231. First zigzag cavity structure.

Detailed ways

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways defined and covered by the claims.

The present invention provides a heat sink for chips with high heat flux density, including a water-cooled heat dissipation plate 9, a micropump 5, a micro-channel heat dissipation structure 11, a built-in temperature sensor 3 and a functional chip 13, a micro-channel heat dissipation structure 11 and a water-cooled heat dissipation plate The two sides of 9 are respectively provided with micro-channel heat dissipation structure cooling medium inlet 21, water-cooled heat dissipation plate cooling medium flow inlet 19 and micro-channel heat dissipation structure cooling medium outflow port 22, and micropump 5 is provided with water-cooled heat dissipation plate liquid backflow Inlet 6, microchannel cooling plate liquid return inlet 14 and water cooling cooling plate liquid returning outlet 15, microchannel cooling plate liquid returning outlet 8, microchannel cooling structure cooling working medium outlet 22 and water cooling cooling plate cooling working medium outlet 20 pass through The hose is connected to the cooling medium inlet 25 of the water storage tank 23, and the cooling medium outlet 24 is connected to the cooling medium return inlet 6 of the micropump 5 and the cooling medium return inlet 14 of the micro-channel heat dissipation plate through the hose. The tubes are connected to the micro-channel heat dissipation structure 11 and the water-cooled heat dissipation plate 9, the micro-channel heat dissipation structure 11 is fixed above the functional chip 13 to absorb the heat generated by the work, the water-cooled heat dissipation plate 9 is fixed above the silicon plate 10, and the temperature sensor is arranged on the micro-channel The bottom surface of the heat dissipation structure 11 is used to obtain the temperature, and the functional chip 13 is connected with the temperature sensor 3 and the micropump 5 for sending different control signals when obtaining heat flux densities corresponding to different temperatures.

Referring to FIG. 1 , FIG. 2 and FIG. 3 , the micropump 5 is mounted on the PCB 1 through the micropump fixing feet 7 , and the functional chip 13 is fixed on the PCB 1 through the chip pins 16 . The assembly method of the microchannel heat dissipation structure 11 is directly integrated with the functional chip 13 and etched. The micropump 5 is provided with a liquid return inlet and a liquid return outlet, and both sides of the microchannel heat dissipation structure 11 and the water-cooled heat dissipation plate 9 are provided with a liquid inlet and a liquid outlet. Above the micro-channel heat dissipation structure 11 is a silicon plate 10 and a water-cooled heat dissipation plate 9. The micro-channel heat dissipation structure 11 is connected to the PCB board 1 through silicone grease 12, and the micro-channel heat dissipation structure 11 and the chip 13 are fixed on the PCB board 1 to ensure that the micro-channel There is no relative displacement between the heat dissipation structure 11 , the functional chip 13 and the PCB board 1 . When the functional chip 13 starts to work, the heat flux density is small, generally below 5W/cm ² . At this time, because of the integrated package structure, the heat generated can be dissipated through natural convection of the air; when the functional chip 13 is in operation, the heat flux density is at When the temperature is 5W/cm ² -100W/cm ² , the micropump 5 starts to work when it is energized, the liquid return outlet 15 of the water cooling plate flows out the cooling liquid, and the cooling liquid enters the liquid inlet on the side of the water cooling cooling plate to absorb the heat of the microchannel cooling plate 11 Flow out from the liquid outlet 15 and return to the liquid return inlet 6, and dissipate heat to the micro-channel cooling plate 11 through the cooling liquid; when the heat flux density of the functional chip 13 exceeds 100W/ ^cm2 when the function chip 13 is working, the micro-channel cooling structure participates in the work to realize multi-level The combination of water cooling and heat dissipation enhances the heat dissipation effect.

Preferably, the micro pump 5 is a micro water pump with controllable pumping flow.

The liquid return outlet 8 of the microchannel heat dissipation structure of the micropump 5 and the liquid return outlet 15 of the water-cooled heat dissipation plate are connected to the soft thin pipes that are gradually reduced. The liquid injection port is connected, and the liquid outlets on both sides of the micro-channel cooling plate 11 and the water-cooling cooling plate 9 are connected to the liquid return inlet 14 of the micro-channel cooling plate on the micropump 5 and the liquid return inlet 6 of the water-cooling cooling plate through soft thin pipes. , forming a complete coolant circuit.

The heat flux is calculated by scatter-point measurement, and the temperature difference between the upper and lower surfaces of the microchannel heat sink 11 is converted into heat flux to control the working state of the micropump 5 . The temperature of the upper and lower bottom surfaces of the micro-channel cooling plate 11 is obtained by measuring the temperature of 9 pairs of temperature sensor upper contact pieces 17 and temperature sensor lower contact pieces 18 connected by temperature sensors 3. The temperature is converted into heat flux by the functional chip 13, and the final signal is input to the micropump control The regulator regulates the pumping flow of liquid.

The hydraulic diameter of the micropump 5 is between 0.1 mm and 1 mm. When the operating temperature of the functional chip 13 exceeds 80° C., the pumping volume of the micropump 5 will automatically increase.

Preferably, the microchannel heat dissipation structure 11 includes a microchannel structure 2 , the microchannel 2 is etched on the bottom of the silicon plate 10 , and the microchannel heat dissipation structure 11 is directly etched on the functional chip 13 .

Preferably, the microchannel 2 includes a hollow structure and a protrusion structure, and the arrangement density of the protrusion structures near the liquid inlet is smaller than that of the protrusion structures near the liquid outlet.

As shown in Figure 4, the inside of the microchannel heat dissipation structure 11 is composed of a plurality of parallel microchannels 2. From its enlarged view A, it is found that the voids or protrusions in the microchannel 2 are along the flow direction of the cooling liquid, and the water-cooled heat dissipation plate The flow direction of the cooling liquid is opposite to that of the microchannels, and its arrangement conforms to the rule that the front is sparse and the rear is dense, and the front is high and the rear is low. Through the arrangement of the ribs offset, the heat transfer performance is significantly improved compared with the arrangement of symmetrical ribs, and the pressure drop is significantly lower than that of the uniform arrangement through the arrangement of sparse front and back. The arrangement, from the coordination of the velocity field and the temperature field, makes the temperature distribution on the chip 13 more uniform and realizes the optimization of heat dissipation.

The protruding structure or cave structure can terminate and regenerate the thermal boundary layer formed by the fluid, thereby increasing the Nusselt number of heat transfer. Etched protrusions or caves can disrupt the flow and break the thermal boundary layer.

Preferably, the protruding structures include isosceles triangular protruding structures, circular arc protruding structures, trapezoidal protruding structures and zigzag protruding structures, isosceles triangular cave structures, circular arc cave structures, trapezoidal cave structures and zigzag cave structures.

As shown in Figure 5, for the composition of the microchannel 2 in the microchannel heat dissipation structure 11, its protrusion or cavity structure is not limited to the isosceles triangular cavity structure 201, the arc-shaped cavity structure 211, the isosceles trapezoidal cavity structure 221, the first sawtooth The hollow structure 231 is the first zigzag protruding structure 241 .

The various protruding structures mentioned above all play a similar role in the principle of destroying the thermal boundary layer. The heat transfer effects of different structures are different in terms of the specific heat transfer enhancement effect, but compared with the straight channel, they all have a significant heat transfer enhancement effect. .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (3)

1. A cooling device for high-power and high-heat-flux chip packaging, characterized in that it includes a water-cooled cooling plate, a micropump, a water storage tank, a micro-channel cooling structure, a temperature sensor and a functional chip, and the two sides of the micro-channel cooling structure A cooling fluid injection port and a cooling fluid outlet are provided, and the micropump is provided with a cooling fluid return inlet and a cooling medium return outlet, and the cooling medium outlet and the cooling medium return inlet are connected by a hose , the microchannel heat dissipation structure is etched above the chip to absorb the heat generated by the chip operation, the water cooling heat dissipation plate is fixed above the silicon plate on the microchannel heat dissipation structure, and the temperature sensor passes through the sensing contact sheet evenly distributed on the surface and the lower contact The sensor sheet is respectively arranged on the upper surface and the lower surface of the functional chip to obtain the temperature difference between the upper and lower surfaces of the functional chip, and the functional chip is connected with the temperature sensor, the water-cooled heat sink and the micro-pump for Different control signals are sent when the heat flux corresponding to different temperatures is obtained. The heat dissipation device for chips with high heat flux according to claim 1, wherein the micropump has a controllable pumping flow. A heat dissipation device for high heat flux density chips according to claim 1, characterized in that, the water storage tank cools the cooling working fluid returned by the water-cooled heat dissipation plate and the microchannel heat dissipation structure, and the micropump acts as a heat sink. outflow. The heat dissipation device for high heat flux chips according to claim 1, wherein the material of the microchannel heat dissipation structure is silicon, and microchannels are etched inside the microchannel heat dissipation structure, which are directly connected to the on chip. 2. A kind of heat dissipation device for high heat flux density chip according to claim 1, it is characterized in that, described microchannel comprises cavity structure and protruding structure, the described protruding structure near described cooling working fluid injection port The arrangement density is smaller than the arrangement density of the protruding structures near the outlet of the cooling working medium. According to research, the cavity structure in the microchannel cooling device adopts the arrangement mode of sparse front and dense rear, low front and high rear, and the heat dissipation effect is the best when the rib height varies in the range of 15-35 μm. 3. A heat dissipation device for a high heat flux chip according to claim 2, wherein the protruding structure comprises an isosceles triangular cavity structure, an arc-shaped cavity structure, a trapezoidal cavity structure and a zigzag cavity structure .