A microchannel device and processing method for heat dissipation of high-power semiconductor chips

Abstract

The present invention relates to the field of electronic component housing production and packaging, and specifically to a microchannel device for dissipating heat from high-power semiconductor chips and a processing method thereof. The microchannel device includes a heat dissipation core formed by a plurality of heat sinks arranged in a staggered manner and blocking plates arranged at the front and rear ends of the heat dissipation core; the heat sink is in the shape of a hexagon containing two adjacent right angles and six internal obtuse angles, and a hollow groove is processed on the heat sink, and a water channel is formed inside the heat dissipation chip through the hollow groove; the microchannel device also includes a groove arranged at the bottom and a water inlet and outlet connected to the water channel. The microchannel device provided by the present invention can avoid the problem that the heat dissipation channel in a traditional heat dissipation device has insufficient strength at the root of the internal heat dissipation fin under the use of a high-pressure cold medium flow, which is prone to breakage, thereby affecting the overall heat dissipation and causing chip failure.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor chip heat dissipation, and in particular to a microchannel device for heat dissipation of a high-power semiconductor chip and a processing method thereof. Background Art

[0002] With the increase in chip power and integration in the semiconductor industry, the heat generation power of single chips has increased significantly. The existing air-cooling and water-cooling technologies can no longer meet the heat dissipation needs of single chips with higher power. In addition, the cooling performance of traditional water-cooling devices is limited by the water flow rate. If the water flow rate is continuously increased, a large water pressure will be formed inside the channel, and its inner cavity channel will be difficult to meet the stress generated by the water flow pressure. Long-term use will cause the internal channel of the radiator to fail, resulting in water cooling failure, and eventually causing the chip to overheat and burn, affecting the reliability of the entire device. In addition, the water pump system pressure demand is relatively large outside the microchannel, and the cost also increases significantly. Moreover, the existing water-cooling devices are mostly processed by silver-copper brazing. Silver-copper brazing is difficult to process due to the brazing material Ag. 72 Cu 28 The thermal conductivity of the device is usually lower than that of the main body material, so the heat dissipation efficiency will also be limited. Summary of the Invention

[0003] In order to solve the problems in the prior art, one of the objectives of the present invention is to provide a microchannel device for dissipating heat from a high-power semiconductor chip at the hundred-watt level.

[0004] The technical solution adopted by the present invention is: a microchannel device for dissipating heat from high-power semiconductor chips, characterized in that the microchannel device includes a heat dissipation core formed by a plurality of heat dissipation fins arranged in a staggered manner and blocking fins arranged at the front and rear ends of the heat dissipation core; the heat dissipation fins are hexagonal and contain two adjacent right angles and four internal obtuse angles, and hollow grooves are machined on the heat dissipation fins, and a water channel is formed inside the heat dissipation chip through the hollow grooves; the microchannel device also includes a groove arranged at the bottom and a water inlet and outlet hole connected to the water channel.

[0005] Preferably, the heat sink is divided into:

[0006] A first heat sink, wherein the hollow groove on the first heat sink includes an independently provided rectangular hollow groove and an L-shaped hollow groove half-surrounding the rectangular hollow groove, and the top ends of the two arms of the L-shaped hollow groove are respectively flush with the corresponding two sides of the rectangular hollow groove;

[0007] A second heat sink, wherein the hollow groove on the first heat sink is formed by connecting the rectangular hollow groove and the top edge of the L-shaped hollow groove on the first heat sink through a connecting groove, and the edge shape of the connecting groove matches the shape of the second heat sink;

[0008] a third heat sink, wherein the hollow grooves on the third heat sink only contain the rectangular hollow grooves in the first heat sink, and are located in the same position;

[0009] The fourth heat sink, wherein the hollow groove on the fourth heat sink only contains the L-shaped hollow groove in the first heat sink, and the positions are the same.

[0010] Preferably, the stacking order of the heat dissipation core starting from the blocking piece at one end is:

[0011] 1) The first heat sinks and the second heat sinks are alternately arranged in 12 groups;

[0012] 2) Place a first heat sink;

[0013] 3) Place 14 third heat sinks;

[0014] 4) The second heat sink and the first heat sink are arranged alternately in 14 groups;

[0015] 5) Place 5 fourth heat sinks;

[0016] 6) The first heat sinks and the second heat sinks are alternately arranged in 13 groups;

[0017] 7) Place a first heat sink;

[0018] 8) Place 14 third heat sinks;

[0019] 9) The second heat sinks and the first heat sinks are arranged alternately in 12 groups;

[0020] 10) Place a second heat sink;

[0021] 11) Finally, place the end plug;

[0022] The blocking fins and the first, second, third and fourth heat sinks are all of the same shape, and their edges are aligned.

[0023] Preferably, the blocking plate and the first heat sink, the second heat sink, the third heat sink and the fourth heat sink are all made of oxygen-free copper, and are all 0.3 mm thick.

[0024] Preferably, the groove and the water inlet and outlet holes are all arranged on the same surface of the microchannel device, the groove has the same width as the microchannel device, and the water inlet and outlet holes are respectively arranged on both sides along the length direction of the groove.

[0025] Preferably, positioning pin insertion holes are provided on both sides along the length direction of the groove, avoiding the water inlet hole and the water outlet hole and not communicating with the water passage.

[0026] A second object of the present invention is to provide a method for preparing a microchannel device, the steps of the method are as follows:

[0027] S1. Position and etch the required hollow grooves for the heat sink on the oxygen-free copper plate, and cut the oxygen-free copper plate into the required heat sink;

[0028] S2. Cutting the unetched oxygen-free copper plate to obtain the plug;

[0029] S3. Place the block on the fixture, then place the heat sinks in the required stacking order and quantity, and finally place the end block.

[0030] S4. Place the arranged heat sinks together with the fixture into a diffusion soldering furnace for diffusion soldering;

[0031] S5. The welded product is subjected to secondary cutting and processing of grooves to obtain the final desired shape of the microchannel device;

[0032] S6. Open a water inlet and a water outlet on the cut microchannel device.

[0033] Preferably, the diffusion welding temperature is 900°C-1100°C.

[0034] Preferably, after S6, the surface of the microchannel device in contact with the chip is further subjected to diamond grinding treatment to ensure that the roughness of the contact surface is less than or equal to 0.2 μm and the flatness is less than or equal to 0.2 μm.

[0035] Preferably, after diamond grinding, the product further includes a coating treatment, the method being as follows: after the water inlet and outlet are blocked with rubber plugs, the outer surface of the microchannel device is electroplated, the coating being a nickel layer or a gold layer, and after the electroplating is completed, the rubber plug is removed.

[0036] The beneficial effects of the present invention are:

[0037] 1) The microchannel device uses a staggered arrangement of heat sinks with hollowed-out slots to form a heat dissipation core. End caps seal the water channels formed by the slots, and water inlet and outlet holes are provided as needed. This structure avoids the problem in traditional heat dissipation devices where the heat dissipation channels, under high pressure and flow of cold medium, lack strength at the base of the internal fins and can cause fractures, thereby affecting overall heat dissipation and leading to chip failure.

[0038] 2) While existing technologies typically utilize integrated water channels, the present invention utilizes multiple heat sinks with varying apertures welded together to form a complete water channel, enabling complex water channel design requirements to be met. Furthermore, the present invention's unique heat sink structure and arrangement significantly turbulent the water flow, thereby increasing heat dissipation efficiency.

[0039] 3) Using high temperature diffusion welding process, compared with the existing brazing technology, it avoids the use of Ag solder commonly used in the existing technology.72 Cu 28 , the entire microchannel device can be made of oxygen-free copper (TU1), which has good material consistency and high heat dissipation rate.

[0040] 4) Diamond grinding is performed on the side of the microchannel device that contacts the chip to ensure that the flatness and roughness of the product meet the standards, which satisfies the requirements of its adhesion to the chip, ensures thermal conductivity, and improves heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic structural diagram of the microchannel device of this application;

[0042] Figure 2 This is a schematic diagram of the microchannel device of the present application used for chip heat dissipation;

[0043] Figure 3 This is a schematic diagram of the structure of the plug in this application.

[0044] Figure 4A This is a schematic structural diagram of the first heat sink in this application. Figure 4B This is a schematic diagram of the structure of the second heat sink in this application. Figure 4C This is a schematic structural diagram of the third heat sink in this application. Figure 4D This is a schematic structural diagram of the fourth heat sink in this application;

[0045] Figure 5 This is an exploded view of the microchannel device of this application.

[0046] The meanings of the symbols in the figure are as follows:

[0047] 1-Microchannel device 10-Heat sink

[0048] 10A-first heat sink 10B-second heat sink 10C-third heat sink 10D-fourth heat sink

[0049] 11-Rectangular hollow groove 12-L-shaped hollow groove 13-Mixed hollow groove

[0050] 20-blocking piece 30-groove 41-water inlet 42-water outlet 50-positioning pin socket 60-chip DETAILED DESCRIPTION

[0051] The technical solution of the present invention is described below in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art.

[0052] Example 1

[0053] like Figure 1 , Figure 3-5As shown, a microchannel device 1 for dissipating heat from high-power semiconductor chips includes a heat dissipation core formed by a staggered arrangement of a plurality of heat sinks 10 and plugs 20 disposed at the front and rear ends of the heat dissipation core; the heat sinks 10 and the plugs 20 are both hexagonal, containing two adjacent right angles and four internal obtuse angles. The shape of the heat sink 10 allows the microchannel device to avoid adjacent components during installation. The heat sink 10 and the plugs 20 are both made of oxygen-free copper and are 0.3mm thick. A groove 30 for positioning and installation is also provided at the bottom center of the microchannel device 1. The groove 30 is the same width as the microchannel device 1 but slightly shorter in length.

[0054] Each heat sink 10 is machined with a hollow groove. When all heat sinks 10 are stacked, the hollow grooves connect to form a water channel. The bottom of the microchannel device 1 is also provided with a water inlet 41 and a water outlet 42 on either side of the groove 30, which communicate with the water channel. A positioning pin insertion hole 50 is also provided, which avoids the water inlet and outlet holes 41 and 42 and does not communicate with the water channel.

[0055] In this embodiment, the heat sink 10 and the blocking piece 20 can be approximately regarded as a shape obtained by connecting the base of an isosceles trapezoid to a rectangle with the same width as the length of its base. The base length, i.e., the width, is 10.67 mm, the height of the trapezoid is 4.00 mm, the angle between the waist of the trapezoid and the base is 60°, and the height of the rectangle is 8.00 mm; the groove 30 has a width of 10.67 mm, a length of 8 mm, and a groove depth of 2 mm.

[0056] The heat sink 10 can be divided into four types according to the different ways of opening the hollow grooves: a first heat sink 10A, a second heat sink 10B, a third heat sink 10C and a fourth heat sink 10D, wherein:

[0057] The hollow groove on the first heat sink 10A includes an independently set rectangular hollow groove 11 and an L-shaped hollow groove 12 that half surrounds the rectangular hollow groove 11. The top ends of the two arms of the L-shaped hollow groove 12 are flush with the two sides of the rectangular hollow groove 11; the hollow groove on the second heat sink 10B is based on the first heat sink 10A, and the top edges of the rectangular hollow groove 11 and the L-shaped hollow groove 12 are connected into one through a connecting groove to form a mixed hollow groove 13. The edge shape of the connecting groove matches the shape of the second heat sink 10B, and the overall shape is trapezoidal; the hollow groove on the third heat sink 10C only contains a rectangular hollow groove 11 that is the same size and setting position as the first heat sink 10A; the hollow groove on the fourth heat sink 10D only contains an L-shaped hollow groove 12 that is the same size and setting position as the first heat sink 10A.

[0058] The rectangular hollow groove 11 is 4.40mm long and 3.10mm wide. The longest sides of the two arms of the L-shaped hollow groove 12 are 7.97mm and 5.3mm respectively. The horizontal arm is parallel to the length of the rectangular hollow groove 11, is 1.2mm wide, and is 1.00mm away from the long side of the rectangular hollow groove 11. The vertical arm is parallel to the width of the rectangular hollow groove 11, is 2.97mm wide, and is 0.50mm away from the short side of the rectangular hollow groove 11. The distance between the L-shaped hollow groove 12 and the bottom edge of each heat sink 10 is 4.10mm, and the distance between it and the left and right sides of each heat sink 10 is 1.40mm. The edge of the connecting groove maintains a distance of 0.5mm from the edge of the second heat sink 10B.

[0059] The arrangement order of the heat sink 10 is: starting from the end block 20, the first heat sink 10A and the second heat sink 10B are alternately arranged and placed in 12 groups continuously, 1 first heat sink 10A is placed, 14 third heat sinks 10C are placed, the second heat sink 10B and the first heat sink 10A are staggered and arranged in 14 groups continuously, 5 fourth heat sinks 10D are placed, the first heat sink 10A and the second heat sink 10B are alternately arranged and placed in 13 groups continuously, 1 first heat sink 10A is placed, 14 third heat sinks 10C are placed, the second heat sink 10B and the first heat sink 10A are alternately arranged and placed in 12 groups continuously, 1 second heat sink 10B is placed, and finally the end block 20 is placed.

[0060] The special structure and arrangement order of the heat sink 10 in this embodiment can change the width and direction of the water passage formed by the hollow grooves, causing greater disturbance to the water flow passing therethrough, thereby increasing the heat dissipation efficiency.

[0061] Example 2

[0062] A method for manufacturing a microchannel device 1 for heat dissipation of high-power semiconductor chips, comprising the following steps:

[0063] S1 positioning and chemically etching the heat sink 10 required hollow groove on the oxygen-free copper plate, and then cutting the etched oxygen-free copper plate into the required heat sink 10;

[0064] S2. Cutting the unetched oxygen-free copper plate to obtain the plug 20;

[0065] S3. Place the plug 20 on the fixture, and then place the heat sink 10 in the desired stacking order and quantity, and finally place the end plug 20;

[0066] S4. The arranged heat sink 10 together with the fixture is placed in a diffusion soldering furnace for diffusion soldering at a soldering temperature of 900 ℃ -1100 ℃;

[0067] S5. The welded product is subjected to secondary cutting and machining of the groove 30 to obtain the desired final shape of the microchannel device 1;

[0068] S6. After cutting, the water inlet 41 and the water outlet 42 are opened on the microchannel device 1;

[0069] S7. Diamond grinding is performed on the surface of the microchannel device 1 in contact with the chip 60 to make the contact surface roughness less than or equal to 0.2 μm and the flatness less than or equal to 0.2 μm;

[0070] S8. Coating treatment: After the water inlet 41 and the water outlet 42 are blocked with rubber plugs, the outer surface of the microchannel device 1 is electroplated with a nickel layer or a gold layer. After the electroplating is completed, the rubber plugs are removed to ensure that the surface of the microchannel device 1 is coated but the interior is not coated.

[0071] Figure 2 The schematic diagram shows the state of the micro-channel device 1 dissipating heat for the chip 60. The surface of the micro-channel device 1 in contact with the chip 60 is polished to fit tightly with the chip 60, thereby improving thermal conductivity and increasing heat dissipation efficiency.

[0072] Example 3

[0073] The microchannel device prepared by the present invention was compared with a heat dissipation device in which the shape of the microchannels in the device was changed. The appearance and material of the microchannel heat dissipation device for comparison were consistent with those of the microchannel device prepared by the present invention, but its water flow channel was processed as a whole and had a diamond straight channel and a rectangular straight channel, respectively.

[0074] Test conditions and process: The power of the test chips is 300W, the heat medium in the water channel is deionized water, and the unified test flow rate is 6L / min; the water inlet temperature of the heat medium is 22℃, and the test environment temperature is 22℃.

[0075] Each test heat sink is as follows Figure 2 The test chip was packaged between two identical heat sinks, which were packaged back-to-back. Deionized water, a heat medium, was introduced directly into the water inlet of the heat sink, with a flow rate of 6 L / min. The chip was turned on, and after the system stabilized, an infrared temperature sensor was used to measure the maximum temperature of each test chip. The blank control group was not equipped with any heat sink. The temperature data is shown in the following table:

[0076]

[0077] It can be seen that in this experiment, after running for a period of time, the maximum temperature of the chip stabilized at 74°C. The two groups of heat dissipation devices using straight water channels, namely parallel straight microchannels and diamond-shaped microchannels, had similar heat dissipation efficiencies. The test chip temperatures were 44°C and 43°C, respectively, with a temperature reduction of approximately 40%. The improved microchannel device of the present invention maintained the temperature of the test chip at 35°C, with a temperature reduction of approximately 53%, which is much higher than other heat dissipation devices. Under the same water cooling conditions, the microchannel device provided in this application has better heat dissipation effect and is more suitable for the heat dissipation needs of high-power chips.

[0078] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A microchannel device for heat dissipation of high-power semiconductor chips, characterized in that: The microchannel device (1) comprises a heat dissipation core formed by staggered arrangement of a plurality of heat dissipation fins (10) and blocking fins (20) arranged at the front and rear ends of the heat dissipation core; the heat dissipation fins (10) are hexagonal and include two adjacent right angles and four internal obtuse angles; the heat dissipation fins (10) are processed with hollow grooves, and a water passage is formed inside the heat dissipation chip through the hollow grooves; the microchannel device (1) further comprises a groove (30) arranged at the bottom, and a water inlet hole (41) and a water outlet hole (42) connected to the water passage; The heat sink (10) is divided into: A first heat sink (10A), wherein the hollow groove on the first heat sink (10A) comprises an independently arranged rectangular hollow groove (11) and an L-shaped hollow groove (12) semi-enclosing the rectangular hollow groove (11), and the top ends of the two arms of the L-shaped hollow groove (12) are respectively flush with the corresponding two sides of the rectangular hollow groove (11); A second heat sink (10B), wherein the mixed hollow groove (13) on the second heat sink (10B) is obtained by connecting the top edges of the rectangular hollow groove (11) and the L-shaped hollow groove (12) on the first heat sink (10A) into one piece through a connecting groove, and the edge shape of the connecting groove matches the shape of the second heat sink; the edge refers to the position of the connecting groove facing the adjacent inner obtuse angles of the two middle parts of the hexagon; a third heat sink (10C), wherein the hollow grooves on the third heat sink (10C) only contain the rectangular hollow grooves (11) in the first heat sink (10A), and are located in the same position; A fourth heat sink (10D), wherein the hollow groove on the fourth heat sink (10D) only contains the L-shaped hollow groove (12) in the first heat sink (10A), and the positions are the same; the stacking order of the heat sink core starting from the end blocking piece (20) is: 1) The first heat sinks (10A) and the second heat sinks (10B) are alternately arranged in 12 groups; 2) Place a first heat sink (10A); 3) Place 14 third heat sinks (10C); 4) The second heat sinks (10B) and the first heat sinks (10A) are staggered in 14 groups; 5) Place five fourth heat sinks (10D); 6) The first heat sinks (10A) and the second heat sinks (10B) are alternately arranged in 13 groups; 7) Place a first heat sink (10A); 8) Place 14 third heat sinks (10C); 9) The second heat sinks (10B) and the first heat sinks (10A) are alternately arranged in 12 groups; 10) Place a second heat sink (10B); 11) Finally, place the end plug (20); The blocking piece (20) and each vertex of the first heat sink (10A), the second heat sink (10B), the third heat sink (10C), and the fourth heat sink (10D) all remain overlapped.

2. A microchannel device for heat dissipation of high-power semiconductor chips according to claim 1, characterized in that: The blocking piece (20) and the first heat sink (10A), the second heat sink (10B), the third heat sink (10C), and the fourth heat sink (10D) are all made of oxygen-free copper and have a thickness of 0.3 mm.

3. A microchannel device for heat dissipation of high-power semiconductor chips according to claim 1, characterized in that: The groove (30) and the water inlet (41) and the water outlet (42) are all arranged on the same surface of the microchannel device (1); the groove (30) and the microchannel device (1) have the same width; the water inlet (41) and the water outlet (42) are respectively arranged on both sides along the length direction of the groove (30).

4. A microchannel device for heat dissipation of high-power semiconductor chips as claimed in claim 3, characterized in that: Positioning pin insertion holes (50) are also provided on both sides along the length direction of the groove (30), avoiding the water inlet hole (41) and the water outlet hole (42) and not communicating with the water passage.

5. A method for processing a microchannel device for heat dissipation of a high-power semiconductor chip according to any one of claims 1 to 4, characterized in that: Here are the steps: S1. Positioning and etching the required hollow grooves for the heat sink (10) on the oxygen-free copper plate, and cutting the oxygen-free copper plate into the required heat sink (10); S2. Cutting the unetched oxygen-free copper plate to obtain a plug (20); S3. Place the plug (20) on the fixture, then place the heat sinks (10) in the required stacking order and quantity, and finally place the end plug (20); S4. Place the arranged heat sink (10) together with the fixture into a diffusion soldering furnace for diffusion soldering; S5. The welded product is subjected to secondary cutting and machining of the groove (30) to obtain the desired final shape of the microchannel device (1); S6. Opening a water inlet hole (41) and a water outlet hole (42) and / or a positioning pin insertion hole (50) on the cut microchannel device (1).

6. The method for processing a microchannel device for heat dissipation of a high-power semiconductor chip according to claim 5, characterized in that: The welding temperature of the diffusion welding is 900° C.-1100° C.

7. The method for processing a microchannel device for heat dissipation of a high-power semiconductor chip according to claim 5, characterized in that: After S6, the surface of the microchannel device (1) in contact with the heat dissipation chip (60) is subjected to diamond grinding treatment to ensure that the roughness of the contact surface is less than or equal to 0.2 μm and the flatness is less than or equal to 0.2 μm.

8. The method for processing a microchannel device for heat dissipation of a high-power semiconductor chip according to claim 7, characterized in that: After polishing, the product also includes a coating treatment, the method being as follows: after using a rubber plug to block the water inlet (41) and the water outlet (42), the outer surface of the microchannel device (1) is electroplated, the coating being a nickel layer or a gold layer, and the rubber plug is removed after the electroplating is completed.

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