Solid-state microwave source

Abstract

The utility model belongs to the field of microwave heating, and discloses a solid-state microwave source which comprises a circuit board and a radio frequency connector connected with the circuit board, a heating element is arranged on the circuit board and connected with a first heat dissipation component through a heat sink, and one side, far away from the first heat dissipation component, of the circuit board is detachably connected with a cover plate. An installation step is arranged on the surface of the first heat dissipation component and extends to at least one side edge of the first heat dissipation component, the heat sink is arranged in the installation step, and a second heat dissipation component is fixedly connected in the installation step and outside the side edge of the heat sink. According to the utility model, the heat sink is arranged on the surface of the heat dissipation component through the open type step structure, so that the heat dissipation effect is further enhanced, the easily damaged heating component and the radio frequency load can be independently drawn out without opening the cover plate, the replacement is more convenient, the repeated work of releasing stress by melting welding spots for the second time is avoided, and the working efficiency is improved. And the microwave oven is better in safety performance, free of maintenance, long in service life and suitable for microwave generation.

Description

Technical Field

[0001] The utility model belongs to the field of microwave heating, in particular to a solid-state microwave source. Background Art

[0002] In recent years, the microwave heating market has expanded annually, and the demand for solid-state microwave sources has also increased. With advances in gallium nitride material processing, particularly the rapid development of high-power gallium nitride RF chips driven by 5G technology, the power level of solid-state microwave sources has also gradually increased. With the advantages of controllable power, frequency, and phase, solid-state microwave sources are increasingly replacing older heating technologies such as magnetrons in the microwave heating field.

[0003] However, during operation, the final power amplifier tubes in the RF circuit generate a significant amount of heat, making heat dissipation a major constraint on the development of solid-state microwave sources. Chinese utility model patent publication number CN212277180 discloses a solid-state microwave source and cooking device that utilizes a substrate bonded to the heating element to improve the heat dissipation capability of the solid-state source. While this improves heat dissipation to a certain extent, the effect remains limited. Utility Model Content

[0004] In order to solve the above deficiencies in the prior art, the present invention aims to provide a solid-state microwave source to further enhance the heat dissipation effect.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: a solid-state microwave source, comprising a circuit board and a radio frequency connector connected to the circuit board, a heating element being provided on the circuit board, the heating element being connected to a first heat dissipation component via a heat sink, a cover being detachably connected to a side of the circuit board away from the first heat dissipation component, a mounting step being provided on the surface of the first heat dissipation component, the mounting step extending to at least one side edge of the first heat dissipation component, the heat sink being provided in the mounting step, and a second heat dissipation component being fixedly connected inside the mounting step and outside the side edge of the heat sink.

[0006] As a limitation of the present invention: the second heat dissipation component is adapted to the side edge size of the heat sink, and a tooth-shaped heat dissipation structure is formed on the second heat dissipation component.

[0007] As a limitation of the present invention: the mounting step extends to two adjacent outer edges of the first heat dissipation component, the second heat dissipation component is fixed to one outer edge of the mounting step, and the edge of the heat sink extends to the other outer edge of the mounting step;

[0008] The circuit board includes a disassembly plate fixedly connected to the heat sink and flush with the outer edge of the heat sink, and a control board fixedly connected to the first heat dissipation component, so that the heat sink, the disassembly plate and the heat-generating component can be withdrawn from the solid-state microwave source together.

[0009] As a limitation of the present utility model: the disassembly plate includes a power amplifier matching circuit board for setting a heating element, and also includes a radio frequency load circuit board for setting a radio frequency load, and the power amplifier matching circuit board and the radio frequency load circuit board are independent of each other; the heat sink includes a power amplifier matching heat sink flush with the power amplifier matching circuit board, and also includes a radio frequency load heat sink flush with the radio frequency load circuit board, and the power amplifier matching heat sink and the radio frequency load heat sink are independent of each other, so that the power amplifier matching circuit board and the power amplifier matching heat sink can be pulled out from the solid-state microwave source together, and the radio frequency load circuit board and the radio frequency load heat sink can be pulled out from the solid-state microwave source together.

[0010] As a limitation of the present invention: the radio frequency connector is connected to the circuit board by extending to the outer edge of the mounting step through the heat sink.

[0011] As a limitation of the present invention: flexible metal is filled between the heat sink and the first heat dissipation component.

[0012] As a limitation of the present invention: a connector bracket is fixedly connected to the edge of the heat sink, so that the lower part of the RF connector is fixedly connected to the heat sink, and the upper part is fixedly connected to the connector bracket.

[0013] As a limitation of the present invention: the connector bracket is provided with an avoidance groove for facilitating the connection of the radio frequency connector with the ceramic strip line of the circuit board.

[0014] As a limitation of the present invention: the cover plate is an integrated cover plate, and a partition wall for dividing the cavity is provided on the side of the cover plate facing the circuit board.

[0015] As a limitation of the present invention: the heat sink is a copper plate.

[0016] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0017] (1) The heat sink of the present invention is arranged on the surface of the heat dissipation component through an open "step" structure. Compared with the closed "cavity" structure, the open "step" structure not only enables the heat sink to dissipate heat to one side of the first heat dissipation component, but also dissipates heat to the outer edge of the open structure, thereby improving "single-sided heat dissipation" to "three-sided heat dissipation". At the same time, a second heat dissipation component with a tooth-shaped heat dissipation structure is arranged on the outer edge of the open structure, further enhancing the heat dissipation effect;

[0018] (2) The heat sink and circuit board of the utility model adopt a modular design, so that the fragile heating components and RF loads can be independently pulled out without opening the cover. The design is ingenious and replacement is more convenient;

[0019] (3) A connector bracket is provided between the RF connector and the heat sink of the present invention, so that the lower part of the RF connector is fixedly connected to the heat sink, and the upper part is fixedly connected to the connector bracket. When the solid-state microwave source is assembled, the four fixing points of the RF connector can be installed at one time. This not only avoids the repeated work of melting the solder joints to release stress when the upper part of the RF connector is connected to the cover plate, but also eliminates the need for a split design of the cover plate, so that the cover plate is improved to an integrated structure. This not only reduces the production cost, but also reduces the gap of the microwave source, reduces the radiation power value, further avoids the leakage of microwaves, and has better safety performance for civilian scenarios.

[0020] (4) The present invention innovatively uses flexible metal as an interface filler between the heat sink and the first heat dissipation component to replace thermal grease or thermal pads. While reaching or exceeding the thermal conductivity of the latter, it avoids the influence of the drying and aging phenomenon of the thermal grease and thermal pads caused by long-term use on the heat dissipation effect (generally, the life of a solid-state microwave source is about ten years, but the thermal grease and thermal pads will dry out and age in the third year), which greatly improves the maintenance-free service life of the solid-state microwave source.

[0021] To sum up, the heat sink of the utility model is arranged on the surface of the heat dissipation component through an open "step" structure, which further enhances the heat dissipation effect, so that the fragile heat-generating components and RF loads can be independently withdrawn without opening the cover, making replacement more convenient, and avoiding the repetitive work of secondary melting of solder joints to release stress. It also has better safety performance, maintenance-free and long service life, and is suitable for microwave generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0023] Figure 1 A perspective view of an embodiment of the present utility model;

[0024] Figure 2 An exploded view of an embodiment of the present utility model;

[0025] Figure 3 This is a three-dimensional diagram of the cover plate of the embodiment of the utility model in a non-illustrated state;

[0026] Figure 4 This is a schematic diagram of the installation of the radio frequency connector in an embodiment of the present utility model.

[0027] In the figure: 1-first heat dissipation component, 2-mounting step, 3-heat sink, 31-power amplifier matching heat sink, 32-RF load heat sink, 4-second heat dissipation component, 5-heating element, 6-RF load, 7-circuit board, 71-control board, 72-power amplifier matching circuit board, 73-RF load circuit board, 8-flexible metal, 9-RF connector, 91-connection hole, 92-connecting wire, 10-connector bracket, 101-avoidance groove, 11-ceramic strip line, 12-cover plate. DETAILED DESCRIPTION

[0028] The preferred embodiment of the present invention is described below with reference to the accompanying drawings. It should be understood that the solid-state microwave source described herein is a preferred embodiment and is only used to illustrate and explain the present invention, and does not constitute a limitation of the present invention.

[0029] The directional terms or positional relationships such as "up", "down", "left" and "right" described in the present invention are based on the directional relationships in the drawings of the present invention specification and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the content protected by the present invention. Example

[0030] This embodiment Figures 1-4 As shown, a solid-state microwave source includes a circuit board 7 and a radio frequency connector 9 connected to the circuit board 7. A heating element 5 is provided on the circuit board 7. The heating element 5 is connected to a first heat dissipation component 1 through a heat sink 3. A cover 12 is detachably connected to the side of the circuit board 7 away from the first heat dissipation component 1.

[0031] Specifically, the first heat sink 1 in this embodiment is a cubic aluminum member. A plurality of parallel heat sink teeth are formed at the lower end of the first heat sink 1 to increase the heat dissipation area and improve the heat dissipation effect. Of course, the first heat sink 1 can also be an alloy member. A mounting step 2 is defined on the upper surface of the first heat sink 1, within which a heat sink 3 is disposed.

[0032] The mounting step 2 is an open structure, extending to at least one side edge of the first heat sink 1. Specifically, the mounting step 2 forms a plane lower than the top surface of the first heat sink 1, and this lower plane extends through at least one side edge of the first heat sink 1. When the heat sink 3 is disposed within the mounting step 2, the side edge of the heat sink 3 can be exposed from the side edge of the first heat sink 1. The solid-state microwave source in this embodiment has a symmetrical structure, with two mounting steps 2 symmetrically disposed on the top surface of the first heat sink 1. Each mounting step 2 extends to the front edge and corresponding left and right edges of the first heat sink 1. Similarly, the heat sink 3 is also symmetrically disposed within the mounting step 2, and the specific shape of the mounting step 2 matches the shape of the heat sink 3.

[0033] The heat sink 3 is preferably a copper plate. In the front-to-back direction, the size of the heat sink 3 is equal to the size of the mounting step 2, so that the front edge of the heat sink 3 is flush with the front edge of the first heat dissipation component 1. In the left-to-right direction, the size of the heat sink 3 is slightly smaller than the size of the mounting step 2. When the heat sink 3 is installed within the mounting step 2, the left and right ends of the two heat sinks 3 are retracted into the left and right edges of the first heat dissipation component 1. Within the mounting step 2, outside the left and right edges of the heat sink 3, a second heat dissipation component 4 is detachably fixed for further heat dissipation. The second heat dissipation component 4 is a strip-shaped structure with a plurality of heat dissipation teeth arranged parallel in the front-to-back direction formed on its lower end surface. The size of the second heat dissipation component 4 in the front-to-back direction is consistent with the size of the heat sink 3 in the front-to-back direction, and the size of the second heat dissipation component 4 in the left-to-right direction corresponds to the size of the heat sink 3 retracted into the first heat dissipation component 1. After installation, the second heat dissipation component 4 is flush with the left and right edges of the first heat dissipation component 1. With this arrangement, the original "single-sided heat dissipation" of the heat sink 3 to the first heat dissipation component 1 is improved to "three-sided heat dissipation" to the first heat dissipation component 1, the second heat dissipation component 4 on the left, and the second heat dissipation component 4 on the right, further enhancing the heat dissipation effect.

[0034] The heating element 5 in this embodiment is a final-stage GaN power amplifier tube, nested within and electrically connected to a circuit board 7. The lower end face of the final-stage GaN power amplifier tube is affixed to a heat sink 3, enabling the heat sink 3 to rapidly conduct the substantial heat generated by the final-stage GaN power amplifier tube. To facilitate the individual removal of the fragile final-stage GaN power amplifier tube and RF load 6 within the solid-state microwave source, both the circuit board 7 and the heat sink 3 in this embodiment employ a modular design. Specifically, the circuit board 7 includes a disassembly plate that is securely connected to and flush with the outer edge of the heat sink 3, and a control board 71 securely connected to the first heat sink 1. This allows the heat sink 3, disassembly plate, and heating components to be withdrawn from the solid-state microwave source together. Furthermore, to allow the heating element 5 and the RF load 6 to be removed separately, the disassembly panel includes a power amplifier matching circuit board 72 for setting the final-stage gallium nitride power amplifier tube, and a RF load circuit board 73 for setting the RF load 6. The power amplifier matching circuit board 72 and the RF load circuit board 73 are independent of each other. Accordingly, the heat sink 3 includes a power amplifier matching heat sink 31 flush with the power amplifier matching circuit board 72, and also includes a RF load heat sink 32 flush with the RF load circuit board 73. The power amplifier matching heat sink 31 and the RF load heat sink 32 are independent of each other, allowing the power amplifier matching circuit board 72 and the power amplifier matching heat sink 31 to be withdrawn from the solid-state microwave source together, and the RF load circuit board 73 and the RF load heat sink 32 to be withdrawn from the solid-state microwave source together. The plug-and-play modular design is ingeniously conceived, not only facilitating production and installation, but also facilitating the individual replacement of vulnerable parts.

[0035] like Figure 2As shown, a flexible metal 8 is filled between the heat sink 3 and the first heat dissipation component 1 as an interface filler instead of thermal grease or thermal pad. The flexible metal 8 in this embodiment is a lead-free solder sheet with a model of SAC305 and a melting point of 217°C. While reaching or exceeding the thermal conductivity of the thermal grease or thermal pad, it avoids the influence of the thermal grease and thermal pad's long-term drying and aging on the heat dissipation effect, thereby greatly improving the maintenance-free service life of the solid-state microwave source.

[0036] The RF connector 9 extends through the heat sink 3 to the outer edge of the mounting step 2, where it connects to the circuit board 7. A connector bracket 10 is fixedly attached to the upper end of this outer edge of the heat sink 3. The heat sink 3 is provided with a first mounting hole extending vertically through the heat sink 3. The lower end surface of the connector bracket 10 is provided with a second mounting hole (not shown) that matches the mounting hole. The connector bracket 10 is mounted on the heat sink 3 using threaded fasteners. The end surface of the RF connector 9 used for connection to the solid-state microwave source is a rectangular plane, with a connection hole 91 at each of its four corners. The two lower connection holes 91 of the RF connector 9 are fixed to the front end surface of the heat sink 3 via threaded fasteners, while the two upper connection holes 91 are fixed to the front end surface of the connector bracket 10 via threaded fasteners. In the prior art, since the RF connector 9 needs to have its connecting wires 92 sintered together with the ceramic strip wires 11 of the circuit board 7 after installation, the cover plate 12 is generally designed as a split structure, including a press frame and a closing plate on the top of the press frame. When installing the RF connector 9, first fix the two connecting holes 91 below the RF connector 9 to the front end surface of the heat sink 3 through threaded fasteners, and install the press frame on the first heat dissipation component 1. Since the press frame is a frame structure, the connecting wires 92 and the ceramic strip wires 11 of the RF connector 9 are exposed at this time. After the connecting wires 92 and the ceramic strip wires 11 of the RF connector 9 are sintered, the two connecting holes 91 on the upper part of the RF connector 9 are fixed to the press frame through threaded fasteners. However, when connecting the upper threaded fasteners, stress will appear between the two upper connection points and the two lower connection points. After all four connection points are connected, the solder joints of the connecting wires 92 and the ceramic strip wires 11 of the RF connector 9 need to be melted a second time to release the above stress. In this embodiment, as Figure 4As shown, since the connector bracket 10 is provided, the connector bracket 10 is directly connected to the heat sink 3. When the RF connector 9 needs to be installed, the four connection holes 91 of the RF connector 9 can be fixed at one time, and then the connecting wire 92 and the ceramic strip wire 11 can be sintered, avoiding the work of secondary melting of the solder joint to release stress. Furthermore, a avoidance groove 101 is provided in the middle of the connector bracket 10 for facilitating the connection of the RF connector 9 with the ceramic strip line 11 of the circuit board 7. The avoidance groove 101 is a through groove, which can be used to weld the RF connector 9 connecting wire 92 and the ceramic strip line 11 when the connectors are installed. In this way, the cover plate 12 can be integrated into an integrated structure. A partition wall for dividing the cavity is provided on the side of the cover plate 12 facing the circuit board 7. When the RF connector 9 is connected to the heat sink 3 and the connector connection block, the fixation is completed. The RF connector 9 connecting wire 92 can be directly sintered on the ceramic strip line 11, and the cover plate 12 can be buckled separately, which not only reduces the production cost, but also reduces the gap of the microwave source, reduces the radiation power value, and further avoids the leakage of microwaves, which has better safety performance for civilian scenarios.

[0037] When assembling this embodiment, first sinter and weld the heating element 5, RF load 6 and other components onto the circuit board 7, connect the circuit board 7 to the heat sink 3 by sintering or threaded fastening, place the connector bracket 10 on the heat sink 3 by threaded fastening, install the RF connector 9 and weld the connecting wire 92, finally clamp the flexible metal 8 between the heat sink 3 and the first heat dissipation component 1, connect the heat sink 3 connected with the above components to the first heat dissipation component 1 by threaded fastening, and install the second heat dissipation component 4 and the cover plate 12 with shielding glue applied after the production test is completed.

Claims

1. A solid-state microwave source comprising a circuit board and a radio frequency connector connected to the circuit board, wherein the circuit board is provided with a heating element connected to a first heat sink via a heat sink, and a cover is detachably connected to a side of the circuit board away from the first heat sink, characterized in that: A mounting step is provided on the surface of the first heat dissipation component, and the mounting step extends to at least one side edge of the first heat dissipation component. The heat sink is arranged in the mounting step, and a second heat dissipation component is fixedly connected inside the mounting step and outside the side edge of the heat sink.

2. A solid-state microwave source according to claim 1, characterized in that: The second heat dissipation component is adapted to the side edge size of the heat sink, and a tooth-shaped heat dissipation structure is formed on the second heat dissipation component.

3. A solid-state microwave source according to claim 2, characterized in that: The mounting step extends to two adjacent outer edges of the first heat dissipation component, the second heat dissipation component is fixed to one outer edge of the mounting step, and the edge of the heat sink extends to the other outer edge of the mounting step; The circuit board includes a disassembly plate fixedly connected to the heat sink and flush with the outer edge of the heat sink, and a control board fixedly connected to the first heat dissipation component, so that the heat sink, the disassembly plate and the heat-generating component can be withdrawn from the solid-state microwave source together.

4. A solid-state microwave source according to claim 3, characterized in that: The disassembly plate includes a power amplifier matching circuit board for setting a heating element, and also includes a radio frequency load circuit board for setting a radio frequency load, and the power amplifier matching circuit board and the radio frequency load circuit board are independent of each other; the heat sink includes a power amplifier matching heat sink flush with the power amplifier matching circuit board, and also includes a radio frequency load heat sink flush with the radio frequency load circuit board, and the power amplifier matching heat sink and the radio frequency load heat sink are independent of each other, so that the power amplifier matching circuit board and the power amplifier matching heat sink can be pulled out of the solid-state microwave source together, and the radio frequency load circuit board and the radio frequency load heat sink can be pulled out of the solid-state microwave source together.

5. A solid-state microwave source according to claim 4, characterized in that: The radio frequency connector is extended to the outer edge of the mounting step through a heat sink and is connected to the circuit board.

6. A solid-state microwave source according to claim 1, characterized in that: Flexible metal is filled between the heat sink and the first heat dissipation component.

7. A solid-state microwave source according to any one of claims 1 to 6, characterized in that: The edge of the heat sink is fixedly connected with a connector bracket, so that the lower part of the radio frequency connector is fixedly connected to the heat sink, and the upper part is fixedly connected to the connector bracket.

8. A solid-state microwave source according to claim 7, characterized in that: The connector bracket is provided with an avoidance groove for connecting the radio frequency connector to the ceramic strip line of the circuit board.

9. A solid-state microwave source according to claim 8, characterized in that: The cover plate is an integrated cover plate, and a partition wall for dividing the cavity is provided on the side of the cover plate facing the circuit board.

10. The solid-state microwave source according to claim 1, characterized in that: The heat sink is a copper plate.

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