HEMT power chip heat dissipation module and preparation method thereof

Abstract

The invention relates to the technical field of heat dissipation of HEMT power chips, in particular to a heat dissipation module of an HEMT power chip and a preparation method of the heat dissipation module. The heat dissipation module of the HEMT power chip comprises a glass liquid separation plate, a silicon-based micro-channel plate and a PCB which are sequentially arranged in a stacked mode. The PCB is provided with a window used for accommodating the HEMT power chip. A micro-channel corresponding to the window is carved on the silicon-based micro-channel plate; a liquid inlet, a liquid outlet and a liquid separation flow channel are formed in the glass liquid separation plate; and after the silicon-based micro-channel plate is connected with the glass liquid separation plate, the glass liquid separation plate covers the micro-channel and forms a cooling flow channel, and the liquid separation flow channel is communicated with the cooling flow channel. The silicon-glass runner plate composed of the silicon-based micro-channel plate and the glass liquid separation plate is used for cooling two phases of the HEMT power chip, the heat dissipation efficiency is high, the thickness is small, and the space is saved. The extraction electrodes of the grid electrode, the drain electrode and the source electrode of the HEMT are constructed through PCB connection, and circuit connection and system assembly are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of HEMT power chips, and in particular to a heat dissipation module of a HEMT power chip and a preparation method thereof. Background Art

[0002] High Electron Mobility Transistors (HEMTs), as heterojunction-based semiconductor devices, are characterized by the high carrier mobility of their two-dimensional electron gas channels, enabling high-frequency, high-power density, and high-efficiency electron transmission. However, as HEMT power chips continue to evolve towards miniaturization and higher power density, thermal management becomes increasingly critical.

[0003] Under high-frequency operating conditions, HEMT power chips generate significant Joule heating. If this heat cannot be dissipated promptly, the junction temperature of the chip's micron-scale heat channel will rise sharply. Once the junction temperature of a HEMT power chip exceeds 150°C, the mobility of the two-dimensional electron gas (2DEG) decreases significantly. This not only increases on-resistance and leakage current, but can also cause breakdown, seriously impacting device performance and reliability. Therefore, effective heat dissipation mechanisms have become a key bottleneck in improving the performance of HEMT power chips and expanding their applications.

[0004] Regarding the heat dissipation problem of HEMT power chips, although traditional heat dissipation methods such as metal cold plates and thermal interface materials can improve heat dissipation efficiency, they are difficult to meet the multifunctional integration requirements of HEMT power chips for heat dissipation modules. Specifically, the heat dissipation module of HEMT power chips must meet the following requirements at the same time. First, miniaturization: Compared with HEMT power chips, which are only millimeter-level in size, the heat dissipation module needs to be designed to the same scale, ensuring the heat dissipation function while avoiding a significant increase in package thickness due to additional structures. Second: Electrical function integration: The heat dissipation module needs to directly serve as an extended electrode of the drain or source, forming a low-resistance connection with the chip electrode, especially in high-frequency scenarios to ensure signal integrity. Third, efficient heat dissipation collaborative design: The heat dissipation path needs to match the current flow inside the chip, especially to optimize the heat dissipation path near the gate of the HEMT power chip to minimize the chip's junction temperature.

[0005] However, existing heat dissipation solutions, such as metal cold plates and heat pipes, often cannot simultaneously meet the above requirements. In addition, the thermal expansion coefficients of commonly used metal materials and HEMT power chips do not match, and long-term use may cause thermal stress problems, further affecting device life and stability.

[0006] Therefore, there is an urgent need to develop a new type of heat dissipation module to achieve collaborative design of efficient heat dissipation, electrical function integration and miniaturization, so as to break through the current thermal management bottleneck of HEMT power chips in high-power applications. Summary of the Invention

[0007] The main purpose of the present invention is to provide a heat dissipation module for a HEMT power chip, so as to achieve a coordinated design of efficient heat dissipation, electrical function integration, and miniaturization. The present invention also provides a preparation method for preparing the heat dissipation module for a HEMT power chip.

[0008] To achieve the above objectives, an embodiment of the present invention provides a heat dissipation module for a HEMT power chip, comprising: a silicon-based microchannel plate, a glass separator plate, and a PCB board;

[0009] The glass separatory plate, the silicon-based microchannel plate and the PCB are stacked in sequence;

[0010] The PCB board is provided with a window for accommodating the HEMT power chip;

[0011] The silicon-based microchannel plate is engraved with a microchannel corresponding to the window;

[0012] The glass separating plate is provided with a liquid inlet, a liquid outlet and a liquid separating channel, and the liquid separating channel is connected with the liquid inlet and the liquid outlet; when the silicon-based microchannel plate is connected to the glass separating plate, the glass separating plate covers the microchannel and forms a cooling channel, and the liquid separating channel is connected with the cooling channel.

[0013] Furthermore, the area of ​​the microchannel is larger than the area of ​​the window, and the projection of the window onto the silicon-based microchannel plate is entirely located within the microchannel.

[0014] Furthermore, the liquid separation channel includes a liquid inlet main channel, a liquid outlet main channel, a plurality of liquid inlet branch channels and a plurality of liquid outlet branch channels;

[0015] Any one of the liquid inlet branch channels and any one of the liquid outlet branch channels are arranged at intervals;

[0016] One end of the main liquid inlet channel is connected to the liquid inlet, and the other end is connected to several of the liquid inlet branch channels. A section of the main liquid outlet channel is connected to the liquid outlet, and the other end is connected to several of the liquid outlet branch channels. One end of the liquid inlet branch channel away from the main liquid inlet channel and one end of the liquid outlet branch channel away from the main liquid outlet channel are both connected to the cooling channel.

[0017] Furthermore, the liquid inlet branch channel and the liquid outlet branch channel are alternately arranged in sequence.

[0018] Furthermore, the cooling channel is a pin-fin channel, and the density of the pin-fins near the window in the microchannel is greater than the density of the pin-fins at other positions of the microchannel.

[0019] Another embodiment of the present invention further provides a preparation method for preparing the heat dissipation module of the HEMT power chip;

[0020] The preparation method comprises the steps of:

[0021] Obtaining a silicon wafer, the silicon wafer having a first side and a second side opposite to each other;

[0022] forming a first gold layer on a first side of the silicon wafer;

[0023] Based on the distribution area of ​​the gate of the HEMT power chip, the microchannel area processing area is determined on the second side of the silicon wafer;

[0024] Processing microchannels in the microchannel processing area and processing alignment marks on the second surface of the silicon wafer to obtain a silicon-based microchannel plate;

[0025] Obtain glass wafers;

[0026] Determine the processing area of ​​the liquid separation flow channel based on the microchannel processing area;

[0027] Processing a liquid distribution channel in a liquid distribution channel processing area and processing an alignment mark on a glass wafer;

[0028] Processing a liquid inlet and a liquid outlet connected to a liquid separation channel on a glass wafer to obtain a glass liquid separation plate;

[0029] Connecting the silicon-based microchannel plate and the glass separatory plate based on the alignment marks on the silicon-based microchannel plate and the alignment marks on the glass separatory plate to obtain a silicon-glass flow channel plate;

[0030] Connecting the first gold layer of the silicon-glass flow channel plate to the second gold layer of the HEMT power chip;

[0031] Processing PCB boards with windows and lead electrodes based on HEMT power chips;

[0032] The PCB board is connected to the silicon-glass runner plate, and the PCB board is electrically connected to the HEMT power chip.

[0033] Furthermore, the step of preparing a first gold layer on the first surface of the silicon wafer includes:

[0034] processing a seed layer on a first side of the silicon wafer by magnetron sputtering;

[0035] The seed layer is electroplated with metal gold to thicken the seed layer to obtain a first gold layer.

[0036] Furthermore, the step of processing the microchannels in the microchannel processing area and processing the alignment marks on the second surface of the silicon wafer to obtain a silicon-based microchannel plate includes:

[0037] Processing optical masks based on microchannel processing areas;

[0038] Based on an optical mask, microchannels are etched in the microchannel processing area, and alignment marks are etched on the second side of the silicon wafer to obtain a silicon-based microchannel plate.

[0039] Furthermore, the steps of processing the liquid separation channel in the liquid separation channel processing area and processing the alignment mark on the glass wafer include:

[0040] Processing chemical masks based on the liquid distribution channel processing area;

[0041] Based on a chemical mask, a liquid distribution channel is processed by wet etching in the liquid distribution channel processing area, and an alignment mark is processed on the glass wafer.

[0042] Furthermore, the step of connecting the silicon-based microchannel plate and the glass separatory plate based on the alignment marks on the silicon-based microchannel plate and the alignment marks on the glass separatory plate to obtain a silicon-glass flow channel plate, in which the silicon wafer and the glass wafer are connected using an anodic bonding process.

[0043] Beneficial effects of the present invention:

[0044] The present invention provides a heat dissipation module for a HEMT power chip, comprising: a silicon-based microchannel plate, a glass separator plate, and a printed circuit board (PCB). The glass separator plate, the silicon-based microchannel plate, and the printed circuit board are stacked in sequence. The printed circuit board is provided with a window for accommodating the HEMT power chip. The silicon-based microchannel plate is engraved with microchannels corresponding to the windows. The glass separator plate is provided with a liquid inlet, a liquid outlet, and a liquid separation flow channel, which is connected to the liquid inlet and the liquid outlet. When the silicon-based microchannel plate and the glass separator plate are connected, the glass separator plate covers the microchannel and forms a cooling flow channel, which is connected to the cooling flow channel.

[0045] The HEMT power chip is cooled in two phases by using a silicon-glass flow channel plate composed of a silicon-based microchannel plate and a glass liquid separator. The heat dissipation efficiency is high, especially for the hot spot area near the gate of the HEMT power chip. The application of HFE-7000 working fluid can increase the heat dissipation capacity to 1000W / cm 2The HEMT power chip heat sink module in this embodiment is very thin, typically less than 3 mm, and has a relatively small footprint. This saves space compared to existing heat sink modules and supports the miniaturization of HEMT power chips. The HEMT power chip heat sink module also takes into account the electrical functions of the HEMT power chip. The HEMT gate, drain, and source lead electrodes are constructed through circuit connections on the PCB board, facilitating circuit connection and system assembly. Furthermore, the transparent glass separator plate allows for visual observation of the two-phase flow state during the heat dissipation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 A cross-sectional view of the HEMT power chip and the heat dissipation module of the HEMT power chip provided in an embodiment of the present invention;

[0048] Figure 2 Exploded diagrams of the heat dissipation module of the HEMT power chip provided by an embodiment of the present invention from two perspectives;

[0049] Figure 3 Schematic diagram of the structure of a silicon-based microchannel plate;

[0050] Figure 4 Schematic diagram of the structure of the glass separatory plate;

[0051] Figure 5 It is a structural diagram of the PCB board;

[0052] Figure 6 A schematic diagram of the structure of the connection between a HEMT power chip and a heat dissipation module of the HEMT power chip provided in an embodiment of the present invention;

[0053] Figure 7 for Figure 1 A local enlarged view of point A;

[0054] Figure 8 The present invention provides a flowchart of the preparation method.

[0055] Icon: 1-HEMT power chip; 11-source; 12-drain; 13-gate;

[0056] 2-silicon-based microchannel plate; 21-microchannel; 22-pin fin;

[0057] 3- glass liquid separation plate; 31- liquid inlet; 32- liquid outlet; 33- liquid separation channel; 331- liquid inlet main channel; 332- liquid outlet main channel; 333- liquid inlet branch channel; 334- liquid outlet branch channel;

[0058] 4-PCB board; 41-window; 42-source lead electrode; 43-drain lead electrode; 44-gate lead electrode; 45-conducting hole;

[0059] 51 - nano silver solder; 52 - first gold layer; 53 - second gold layer; 54 - third gold layer. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0061] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0062] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0063] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0064] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0065] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0066] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0067] like Figures 1 to 7 As shown, one embodiment of the present invention provides a heat dissipation module for a HEMT power chip, comprising a silicon-based microchannel plate 2, a glass separator plate 3, and a printed circuit board 4. The glass separator plate 3, silicon-based microchannel plate 2, and printed circuit board 4 are stacked in sequence. The printed circuit board 4 has a square structure and includes a window 41. The shape of window 41 matches that of the HEMT power chip 1 and its area is slightly larger than that of the HEMT feeder chip. The HEMT power chip 1 is mounted within window 41. The printed circuit board 4 comprises a substrate, a copper foil layer, an insulating layer, and a third gold layer 54. The copper foil layer is arranged along paths where electrical signals need to be conducted, depending on the gate 13, drain 12, and source 11 of the HEMT power chip 1. The insulating layer is formed on the copper foil layer in areas where external wiring is not required. The third gold layer 54 is formed on the copper foil layer in areas where external wiring is required. Furthermore, the printed circuit board 4 is provided with vias 45 for electrical connection between the two sides. The silicon-based microchannel plate 2 is engraved with a microchannel 21 corresponding to the window 41. That is, when the silicon-based microchannel plate 2 is connected to the PCB board 4, the projection of the window 41 onto the silicon-based microchannel plate 2 is located within the range of the microchannel 21. The glass liquid separation plate 3 is provided with a liquid inlet 31, a liquid outlet 32 ​​and a liquid separation channel 33. The liquid separation channel 33 is connected to the liquid inlet 31 and the liquid outlet 32. The cooling medium can enter the liquid separation channel 33 through the liquid inlet 31 and then be discharged from the liquid separation channel 33 through the liquid outlet 32. Figure 1 The arrow pointing upwards is the direction of liquid inlet. Figure 1The arrow pointing downward in the middle is the direction of liquid discharge; when the silicon-based microchannel plate 2 is connected to the glass separator plate 3, the silicon-based microchannel plate 2 and the glass separator plate 3 form a silicon-glass flow channel plate, and the glass separator plate 3 covers the surface of the silicon-based microchannel 21 to close the microchannel 21, so that the microchannel 21 forms a cooling channel, and the separator channel 33 is connected to the cooling channel. The cooling medium enters the cooling channel through the separator channel 33, and is then discharged from the cooling channel through the separator channel 33. Under the action of the separator channel 33, the cooling medium can evenly fill the cooling channel, thereby improving the cooling effect.

[0068] In this embodiment, a silicon-glass flow channel plate composed of a silicon-based microchannel plate 2 and a glass liquid separator plate 3 is used to perform two-phase cooling on the HEMT power chip 1. This has high heat dissipation efficiency. In particular, the application of HFE-7000 working fluid to the hot spot area near the gate 13 of the HEMT power chip 1 can increase the heat dissipation capacity to 1000 W / cm 2 The HEMT power chip heat sink module in this embodiment is very thin, typically less than 3 mm, and has a relatively small footprint. This saves space compared to existing heat sink modules and supports the miniaturization of the HEMT power chip 1. The HEMT power chip heat sink module also takes into account the electrical functions of the HEMT power chip 1. The HEMT gate 13, drain 12, and source 11 lead electrodes are constructed through circuit connections on the PCB 4, facilitating circuit connection and system assembly. Furthermore, the transparent glass separator plate 3 allows for visual observation of the two-phase flow during the heat dissipation process.

[0069] Preferably, in this embodiment, the area of ​​the microchannel 21 is larger than the area of ​​the window 41. When the PCB board 4 is connected to the silicon-based microchannel plate 2, the projection of the window 41 onto the silicon-based microchannel plate 2 is all located within the range of the microchannel 21, thereby ensuring a good heat dissipation effect.

[0070] In an optional embodiment, the above-mentioned cooling channel can be a pin-fin channel or a slender channel; when the cooling channel is a pin-fin channel, a plurality of pin-fins 22 are provided in the microchannel 21 of the silicon-based microchannel plate 2, and preferably, the density of the pin-fins 22 in the area near the window 41 in the microchannel 21 is greater than the density of the pin-fins 22 in the rest of the microchannel 21. By arranging denser pin-fins 22 at the window 41, it helps to reduce the temperature of the hot spot area.

[0071] Preferably, in this embodiment, a first gold layer 52 is formed on the side of the silicon-based microchannel plate 2 connected to the PCB board 4 to facilitate the connection between the silicon-based microchannel plate 2 and the HEMT power chip 1 and to form a conductive circuit.

[0072] In an optional embodiment, if Figure 4As shown, the liquid separation channel 33 includes a main liquid inlet channel 331, a main liquid outlet channel 332, a plurality of liquid inlet branch channels 333, and a plurality of liquid outlet branch channels 334. Any liquid inlet branch channel 333 is spaced from any liquid outlet branch channel 334, that is, on the glass liquid separation plate 3, the liquid inlet branch channels 333 and the liquid outlet branch channels 334 are not connected. One end of the main liquid inlet channel 331 is connected to the liquid inlet 31, and the other end is connected to several liquid inlet branch channels 333. One end of the main liquid outlet channel 332 is connected to the liquid outlet 32, and the other end is connected to several liquid outlet branch channels 334. The liquid inlet branch channels 333 and the liquid outlet branch channels 334 are both arranged at intervals along the width direction or length direction of the window 41 so that the cooling medium can fill the cooling channel. The liquid inlet branch channels 333 and the liquid outlet branch channels 334 are connected through the cooling channel of the silicon-glass channel plate, and as a preference, several liquid inlet branch channels 333 and several liquid outlet branch channels 334 are alternately arranged in sequence, thereby improving the liquid separation effect of the liquid separation channel 33 and ensuring that the cooling medium can evenly fill the cooling channel.

[0073] Another embodiment of the present invention also provides a preparation method for preparing the heat dissipation module of the HEMT power chip. Figure 8As shown, when preparing the heat dissipation module for the HEMT feed chip, the silicon-based microchannel plate 2 and the glass separator plate 3 can be prepared simultaneously. During the preparation of the silicon-based microchannel plate 2, a silicon wafer is first prepared. The silicon wafer has a first surface and a second surface facing each other. The first surface is used to connect to the PCB board 4 / HEMT power chip 1, and the second surface is used to connect to the glass separator plate 3. After the silicon wafer is prepared, a first gold layer 52 is formed on the first surface of the silicon wafer to connect to the third gold layer 54 of the PCB board 4 and the second gold layer 53 of the HEMT power chip 1. Next, a microchannel 21 processing area is determined on the second surface of the silicon wafer based on the distribution area of ​​the gate 13 of the HEMT power chip 1. After the microchannel 21 processing area is determined, the microchannel 21 is processed within the microchannel 21 area. At the same time, alignment marks are also processed on the second surface of the silicon wafer to facilitate connection to the glass separator plate 3. After completing the above steps, the silicon-based microchannel plate 2 is obtained. During the preparation of the glass separatory plate 3, a glass wafer is first prepared. After the glass wafer is prepared, the processing area for the separatory channel 33 is determined based on the processing area of ​​the microchannel 21 on the silicon wafer. Once the processing area for the separatory channel 33 is determined, the separatory channel 33 is processed on the glass wafer. At the same time, alignment marks are also processed on the glass wafer to facilitate connection with the silicon-based microchannel plate 2. Finally, a liquid inlet 31 and a liquid outlet 32 ​​connected to the separatory channel 33 are processed on the glass wafer, thereby obtaining the glass separatory plate 3. After obtaining the silicon-based microchannel plate 2 and the glass separatory plate 3, the silicon-based microchannel plate 2 and the glass separatory plate 3 are connected based on the alignment marks on the silicon-based microchannel plate 2 and the alignment marks on the glass separatory plate 3, thereby obtaining a silicon-glass separatory plate with an internal cooling channel. Afterwards, the silicon-glass flow channel plate needs to be diced to form a square silicon-glass flow channel plate. The first gold layer 52 of the silicon-glass flow channel plate also needs to be cleaned to ensure connection with the PCB 4 / HEMT power chip 1. The first gold layer 52 of the silicon-glass flow channel plate is the first gold layer 52 on the first surface of the silicon-based microchannel plate 2. After completing the above steps, the first gold layer 52 of the silicon-glass flow channel plate is connected to the second gold layer 53 of the HEMT power chip 1. The PCB 4 with the window 41 and lead-out electrodes is then fabricated. The PCB 4 is then bonded to the silicon-glass flow channel plate. The PCB 4 is then connected to the source 11, drain, and gate 13 of the HEMT power chip 1 via gold wires / vias 45. This completes the fabrication of the HEMT power chip heat sink module. Finally, external wires are soldered to the PCB 4, and the liquid inlet 31 and outlet 32 ​​are connected to external piping.

[0074] Furthermore, in this embodiment, when preparing the first gold layer 52 on the first surface of the silicon wafer, a Ti / Au seed layer is first processed on the first surface by magnetron sputtering, and the thickness is generally 30-300nm to ensure the bonding strength; then the seed layer is thickened by electroplating to form the first gold layer 52, and the thickness of the first gold layer 52 is generally greater than 4μm.

[0075] Furthermore, in this embodiment, in the steps of processing the microchannels 21 in the microchannel 21 processing region and processing the alignment marks on the second side of the silicon wafer to obtain the silicon-based microchannel plate 2, an optical mask is first processed based on the microchannel 21 processing region; the microchannels 21 are etched in the microchannel 21 processing region based on the optical mask, and the alignment marks are etched on the second side of the silicon wafer based on the optical mask, thereby obtaining the silicon-based microchannel plate 2. By providing the optical mask, the process is simple, efficient, and more precise.

[0076] Furthermore, in this embodiment, in the steps of processing the liquid dispensing channel 33 in the processing area of ​​the liquid dispensing channel 33 and processing the alignment mark on the glass wafer, a chemical mask is first processed based on the processing area of ​​the liquid dispensing channel 33; then, based on the chemical mask, the liquid dispensing channel 33 is processed in the processing area of ​​the liquid dispensing channel 33 by wet etching, and the alignment mark is processed on the glass wafer based on the chemical mask. By preparing the chemical mask, the geometric shape and position of the liquid dispensing channel 33 can be precisely controlled, while also improving the accuracy of the alignment mark.

[0077] Furthermore, in this embodiment, the silicon wafer and the glass wafer are connected using an anodic bonding process.

[0078] Optionally, in this embodiment, the second gold layer 53 of the HEMT feed chip and the first gold layer 52 of the silicon-based microchannel plate 2 may be connected via nano-silver solder 51 .

[0079] In an optional implementation manner in this embodiment, the outer dimensions of the HEMT power chip 1 are 1 mm × 6 mm × 0.2 mm; the outer dimensions of the PCB board 4 are 20 mm × 20 mm × 0.5 mm; the outer dimensions of the silicon-based microchannel plate 2 are 20 mm × 20 mm × 0.5 mm; and the outer dimensions of the glass separatory plate 3 are 20 mm × 20 mm × 0.5 mm.

[0080] Microchannels 21 in the form of pin-fins 22 are etched in the central region of the silicon-based microchannel plate 2. The total etched area is 4 mm x 8 mm, with an etch depth of 250 microns. The etched area is divided into a central region and two flanking regions. The pin-fins 22 retained in the central region have a diameter of 100 microns and a spacing of 160 microns between their centers. The pin-fins 22 retained in the flanking regions have a diameter of 150 microns and a spacing of 300 microns between their centers. The central region corresponds to the primary heat generation area of ​​the HEMT power chip 1. A 4-micron first gold layer 52 is applied to the other side of the silicon-based microchannel plate 2 using a sputtering and gold plating process to achieve a tighter connection with the chip.

[0081] The liquid separation channel 33 etched on the glass liquid separation plate 3 corresponds to the etched area of ​​the silicon-based microchannel plate 2, and the etching depth is 200 microns. The number of liquid outlet branch channels 334 is greater than the number of liquid inlet branch channels 333, and the cross-sectional area of ​​the liquid outlet branch channels 334 is greater than the cross-sectional area of ​​the liquid inlet branch channels 333. Specifically, there are 5 liquid inlet branch channels 333, each with a width of 400 microns; there are 6 liquid outlet branch channels 334, each with a width of 500 microns. The increase in the area of ​​the liquid outlet branch channels 334 helps to discharge the two-phase working fluid that expands in volume after vaporization more smoothly. The diameters of the liquid inlet 31 and the liquid outlet 32 ​​are both 2 mm.

[0082] A square window 41 is machined in the center area of ​​the PCB board 4, and the area of ​​the window 41 is 1.6mm×8mm. The two sides of the long side of the window 41 are the gold wire connection points of the gate 13 and the gold wire connection points of the drain 12. The gold wire connection points of the gate 13 and the gate lead electrode 44 are connected to the circuit through the copper foil layer, and the gold wire connection points of the drain 12 and the drain lead electrode 43 are also connected to the circuit through the copper foil layer. The two sides of the short side of the window 41 are the via 45 and the source lead electrode 42. The via 45 contains copper foil, which can realize the circuit connection between the upper and lower surfaces of the PCB. Therefore, the source lead electrode 42 is connected to the third gold layer 54 on the bottom surface of the PCB through the via 45.

[0083] In the connection method between the electrodes of the HEMT power chip 1 and the heat sink module, the gate 13 of the HEMT power chip 1 is connected to the gate lead electrode 44 via gold wire and copper foil. The drain 12 of the HEMT power chip 1 is connected to the drain lead electrode 43 via gold wire and copper foil. The source 11 of the HEMT power chip 1 is connected to the source lead electrode 42 via the first gold layer 52 of the silicon-based microchannel plate 2, the second gold layer 53 of the PCB 4, and the via 45. This method achieves a circuit connection between the HEMT chip electrodes and the lead electrodes.

[0084] After testing, the heat dissipation module provided by the present invention can 2Under the heat flux density, the junction temperature of the HEMT power chip 1 is guaranteed not to exceed 150°C, meeting the temperature requirements under its high-frequency and high-power operation state.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat dissipation module for a HEMT power chip, characterized in that: include: Silicon-based microchannel plate (2), glass liquid separation plate (3) and PCB board (4); The glass liquid separation plate (3), the silicon-based microchannel plate (2) and the PCB board (4) are stacked in sequence; The PCB board (4) is provided with a window (41) for accommodating the HEMT power chip (1); The silicon-based microchannel plate (2) is engraved with a microchannel (21) corresponding to the window (41); The glass liquid separation plate (3) is provided with a liquid inlet (31), a liquid outlet (32) and a liquid separation flow channel (33), and the liquid separation flow channel (33) is communicated with the liquid inlet (31) and the liquid outlet (32); when the silicon-based microchannel plate (2) is connected to the glass liquid separation plate (3), the glass liquid separation plate (3) covers the microchannel (21) and forms a cooling flow channel, and the liquid separation flow channel (33) is communicated with the cooling flow channel.

2. The heat dissipation module for a HEMT power chip according to claim 1, characterized in that: The area of ​​the microchannel (21) is larger than the area of ​​the window (41), and the projection of the window (41) onto the silicon-based microchannel plate (2) is entirely located within the microchannel (21).

3. The heat dissipation module for a HEMT power chip according to claim 1, characterized in that: The liquid separation channel (33) includes a liquid inlet main channel (331), a liquid outlet main channel (332), a plurality of liquid inlet branch channels (333) and a plurality of liquid outlet branch channels (334); Any one of the liquid inlet branch channels (333) and any one of the liquid outlet branch channels (334) are arranged at intervals; One end of the liquid inlet main channel (331) is connected to the liquid inlet port (31), and the other end is connected to a plurality of the liquid inlet branch channels (333); a section of the liquid outlet main channel (332) is connected to the liquid outlet port (32), and the other end is connected to a plurality of the liquid outlet branch channels (334); one end of the liquid inlet branch channel (333) facing away from the liquid inlet main channel (331) and one end of the liquid outlet branch channel (334) facing away from the liquid outlet main channel (332) are both connected to the cooling channel.

4. The heat dissipation module for a HEMT power chip according to claim 3, characterized in that: The liquid inlet branch channel (333) and the liquid outlet branch channel (334) are alternately arranged in sequence.

5. The heat dissipation module for a HEMT power chip according to claim 1, characterized in that: The cooling flow channel is a pin-fin flow channel, and the density of the pin-fins (22) near the window (41) in the microchannel (21) is greater than the density of the pin-fins (22) at other positions of the microchannel (21).

6. A preparation method, characterized in that: A heat dissipation module for preparing a HEMT power chip according to any one of claims 1 to 5; The preparation method comprises the steps of: Obtaining a silicon wafer, the silicon wafer having a first side and a second side opposite to each other; forming a first gold layer on a first side of the silicon wafer; Based on the distribution area of ​​the gate of the HEMT power chip, the microchannel processing area is determined on the second side of the silicon wafer; Processing microchannels in the microchannel processing area and processing alignment marks on the second surface of the silicon wafer to obtain a silicon-based microchannel plate; Obtain glass wafers; Determine the processing area of ​​the liquid separation flow channel based on the microchannel processing area; Processing a liquid distribution channel in a liquid distribution channel processing area and processing an alignment mark on a glass wafer; Processing a liquid inlet and a liquid outlet connected to a liquid separation channel on a glass wafer to obtain a glass liquid separation plate; Connecting the silicon-based microchannel plate and the glass separatory plate based on the alignment marks on the silicon-based microchannel plate and the alignment marks on the glass separatory plate to obtain a silicon-glass flow channel plate; Connecting the first gold layer of the silicon-glass flow channel plate to the second gold layer of the HEMT power chip; Processing PCB boards with windows and lead electrodes based on HEMT power chips; The PCB board is connected to the silicon-glass runner plate, and the PCB board is electrically connected to the HEMT power chip.

7. The preparation method according to claim 6, characterized in that The step of preparing the first gold layer on the first side of the silicon wafer comprises: processing a seed layer on a first side of the silicon wafer by magnetron sputtering; The seed layer is electroplated with metal gold to thicken the seed layer to obtain a first gold layer.

8. The preparation method according to claim 6, characterized in that The step of processing microchannels in the microchannel processing area and processing alignment marks on the second surface of the silicon wafer to obtain a silicon-based microchannel plate includes: Processing optical masks based on microchannel processing areas; Based on an optical mask, microchannels are etched in the microchannel processing area, and alignment marks are etched on the second side of the silicon wafer to obtain a silicon-based microchannel plate.

9. The preparation method according to claim 6, characterized in that The steps of processing the liquid dispensing channel in the liquid dispensing channel processing area and processing the alignment mark on the glass wafer include: Processing chemical masks based on the liquid distribution channel processing area; Based on a chemical mask, a liquid distribution channel is processed by wet etching in the liquid distribution channel processing area, and an alignment mark is processed on the glass wafer.

10. The preparation method according to claim 6, characterized in that The steps are described as connecting the silicon-based microchannel plate and the glass liquid separation plate based on the alignment marks on the silicon-based microchannel plate and the alignment marks on the glass liquid separation plate to obtain a silicon-glass flow channel plate, in which the silicon wafer and the glass wafer are connected using an anodic bonding process.

Images