Heat dissipation structure for single MOS (Metal Oxide Semiconductor) transistor of photovoltaic inverter

Abstract

The utility model discloses a heat radiation structure for a single MOS tube of a photovoltaic inverter, which comprises a ceramic chip base arranged at the top of a heat radiator and a conductive copper layer arranged on the surface of the top of the ceramic chip base, a tin-bismuth-silver-copper solder paste layer is arranged on the surface of the top of the conductive copper layer, and the MOS tube is attached to the tin-bismuth-silver-copper solder paste layer. According to the utility model, the problems of short service life and high failure rate of components caused by poor heat dissipation performance of a single MOS tube used for a photovoltaic inverter, easy deformation and incomplete filling of a heat-conducting medium and increase of thermal resistance in the prior art are solved.

Description

Technical Field

[0001] The utility model relates to the field of heat dissipation of components and devices, in particular to a heat dissipation structure for a single MOS tube of a photovoltaic inverter. Background Art

[0002] In the prior art, the core component of a solar photovoltaic inverter is the IGBT. Based on the packaging form, the products can be divided into three categories: single IGBT tubes, IPM modules, and IGBT modules. Single IGBT tubes are primarily used in photovoltaic inverters with a power below 20 kW. Currently, thermal grease is used as a heat transfer medium between the MOS tube, alumina or aluminum nitride, and the heat sink. However, the thermal conductivity of commercially available thermal grease is generally only 2 to 5 W / mk. In addition to its low thermal conductivity, thermal grease cannot be applied over large areas in actual process applications and is not reusable. Furthermore, it suffers from poor stability in outdoor environments for extended periods. After continuous thermal cycling, liquid migration occurs, leaving only the filler material with a loss of surface wettability and the risk of failure. The different thermal expansion rates of the interface materials create an "inflation" effect, increasing thermal resistance and reducing heat transfer efficiency, leading to burnout of the MOS tube.

[0003] In view of this, this technical solution proposes a heat dissipation structure for a single MOS tube in a photovoltaic inverter. It adopts a post-coating curing structure - a thermally conductive copper layer formed by high-temperature conductive copper paste, combined with a thermally conductive connection reinforcement layer of tin-bismuth-silver-copper solder paste formed by printing, so that the heat dissipation and connection stability are enhanced, eliminating the risk of failure caused by overheating, dielectric deformation and incomplete filling, and extending the service life of the component. Utility Model Content

[0004] The technical solution of this utility model aims to at least partially address one of the technical problems in the related art. To this end, the main purpose of this utility model is to provide a heat dissipation structure for a single MOS tube in a photovoltaic inverter. This structure aims to address the existing problems of single MOS tubes used in photovoltaic inverters, such as poor heat dissipation performance, deformation of the heat-conducting medium, incomplete filling, increased thermal resistance, shortened component life, and high failure rates.

[0005] To achieve the above objectives, the present invention provides a heat dissipation structure for a single MOS tube in a photovoltaic inverter, comprising a ceramic base disposed on the top of the heat sink, and a conductive copper layer disposed on the top surface of the ceramic base, wherein a tin-bismuth-silver-copper tin paste layer is provided on the top surface of the conductive copper layer, and a MOS tube is attached to the tin-bismuth-silver-copper tin paste layer.

[0006] As a further solution of the present invention, the ceramic base and the heat sink are connected by welding through a copper bottom plate.

[0007] As a further solution of the present invention, the ceramic plate base is an aluminum oxide and aluminum nitride ceramic plate structure.

[0008] As a further solution of the present invention, the tin-bismuth-silver-copper tin paste layer is printed on the surface of the conductive copper layer and is a thermally conductive connection reinforcement layer with the same size as the bottom surface of the MOS tube.

[0009] As a further solution of the present invention, the thickness of the conductive copper layer is 10-35 μm, and the copper layer structure is a copper layer structure made by sintering high-temperature conductive copper paste.

[0010] The beneficial effects of the utility model are as follows:

[0011] This utility model proposes a heat dissipation structure for a single MOS tube in a photovoltaic inverter. By using a ceramic base, a conductive copper layer, and a layer of tin-bismuth-silver-copper paste disposed between the MOS tube and the heat sink, it achieves excellent heat dissipation and high connection strength after final soldering. Because it does not utilize deformable, flexible thermal conductors, there is no flow or liquid migration, thus eliminating the problems of "airing and bulging," ensuring rapid heat conduction and extending the service life of the entire component. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the utility model technical solution or the utility model technical solution in the prior art, the drawings required for use in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model technical solution. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0013] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the heat sink, ceramic base, and MOS tube in the present invention.

[0014] Figure 2 This is a schematic diagram of the arrangement of the ceramic base and the conductive copper layer in the present invention.

[0015] Figure 3 This is a schematic diagram of the tin-bismuth-silver-copper paste layer of the present invention being disposed on the conductive copper layer.

[0016] Figure 4 This is a schematic diagram of the MOS tube in the present invention being arranged on a tin-bismuth-silver-copper solder paste layer.

[0017] Figure 5 This is a schematic cross-sectional diagram of each level of the product of this utility model.

[0018] [Main parts / assembly reference numerals]

[0019] Label name Label name 1 heat sink 12 Tin-bismuth-silver-copper solder paste layer 10 Ceramic base 13 MOS tube 11 Conductive copper layer DETAILED DESCRIPTION

[0020] Please see the attached Figure 1-5 ,

[0021] The main structure includes a ceramic base 10 arranged on the top of the radiator 1, and a conductive copper layer 11 arranged on the top surface of the ceramic base 10. The top surface of the conductive copper layer 11 is provided with a tin-bismuth-silver-copper tin paste layer 12, and a MOS tube 13 is attached to the tin-bismuth-silver-copper tin paste layer 12.

[0022] Here's how it works:

[0023] Using a thick-film printing process, a layer of high-temperature conductive copper paste (curing to form a conductive copper layer 11) is printed on the surface of aluminum oxide and aluminum nitride (ceramic substrate 10) according to the heat dissipation pattern of the MOS tube 13. This is then sintered using a nitrogen-oxygen high-temperature sintering method to form a 10-35μm highly conductive and thermally conductive copper layer. Our tin-bismuth-silver-copper solder paste layer 12 (Sn-3) is evenly applied to the surface of the conductive copper layer 11 using an SMT solder paste brush. Finally, the MOS tube 13 is soldered to the entire ceramic substrate 10 in a vacuum soldering furnace. This layered structure offers significant advantages in heat dissipation and stability, and is particularly valuable in harsh environments such as high temperature, high humidity, high power, and high vibration. Its primary applications include new energy photovoltaic inverters, automotive electronics, charging stations, and communication systems.

[0024] A preferred embodiment of the present invention is that the ceramic base 10 and the radiator 1 are connected by welding through a copper bottom plate.

[0025] The ceramic base 10 can be welded to the surface of the heat sink 1 through a copper base plate, which has both high-strength connectivity and excellent thermal conductivity.

[0026] A preferred embodiment of the present invention is that the ceramic base 10 is an aluminum oxide and aluminum nitride ceramic plate structure.

[0027] Alumina and aluminum nitride ceramic plates have excellent thermal conductivity, good structural strength and strong heat resistance.

[0028] A preferred embodiment of the present invention: the tin-bismuth-silver-copper tin paste layer 12 is printed on the surface of the conductive copper layer 11 and is a thermally conductive connection reinforcement layer of the same size as the bottom surface of the MOS tube 13.

[0029] The Sn / Bi / Ag / Cu paste layer 12 is an intermediate layer, i.e., a thermal conductive connection reinforcement layer disposed between the MOS transistor 13 and the conductive copper layer 11. It has both excellent thermal conductivity and the ability to maintain a high-strength connection after soldering.

[0030] In a preferred embodiment of the present invention, the thickness of the conductive copper layer 11 is 10-35 μm, and the copper layer structure is a copper layer structure made by sintering a high-temperature conductive copper paste.

[0031] The conductive copper layer 11 is formed by sintering and laying high-temperature conductive copper paste through a nitrogen-oxygen high-temperature sintering process.

[0032] The above are only preferred embodiments of the technical solution of the present utility model, and do not limit the patent scope of the technical solution of the present utility model. All equivalent structural transformations made by using the contents of the description and drawings of the technical solution of the present utility model under the conception of the technical solution of the present utility model, or direct / indirect application in other related technical fields are included in the patent protection scope of the technical solution of the present utility model.

Claims

1. A heat dissipation structure for a single MOS tube of a photovoltaic inverter, characterized in that: include A ceramic base is arranged on the top of the radiator, and a conductive copper layer is arranged on the top surface of the ceramic base. The top surface of the conductive copper layer is provided with a tin-bismuth-silver-copper tin paste layer, and a MOS tube is attached to the tin-bismuth-silver-copper tin paste layer.

2. The heat dissipation structure for a single MOS tube of a photovoltaic inverter according to claim 1, characterized in that: The ceramic base and the radiator are connected by welding through a copper bottom plate.

3. The heat dissipation structure for a single MOS tube of a photovoltaic inverter according to claim 1, characterized in that: The ceramic plate base is an aluminum oxide and aluminum nitride ceramic plate structure.

4. The heat dissipation structure for a single MOS tube of a photovoltaic inverter according to claim 1, characterized in that: The tin-bismuth-silver-copper tin paste layer is printed on the surface of the conductive copper layer and is a thermally conductive connection reinforcement layer with the same size as the bottom surface of the MOS tube.

5. The heat dissipation structure for a single MOS tube of a photovoltaic inverter according to claim 1, characterized in that: The thickness of the conductive copper layer is 10-35 μm, and the copper layer structure is a copper layer structure made by sintering high-temperature conductive copper paste.

Images