A packaging structure of a power semiconductor packaging device

Abstract

The invention relates to the field of packaging technology, and discloses a packaging structure of a power semiconductor packaging device, comprising: a plastic package body and a heat dissipation base plate partially embedded in the top of the plastic package body, wherein a double-sided copper-clad ceramic substrate 1, a power chip, a metal heat conductive sheet, a double-sided copper-clad ceramic substrate 2 and a lead frame are encapsulated in the plastic package body; the first electrode of the power chip is connected to the bottom of the heat dissipation base plate through the double-sided copper-clad ceramic substrate 1, the second electrode is connected to the double-sided copper-clad ceramic substrate 2 through the metal heat conductive sheet, and the lead frame is connected to the double-sided copper-clad ceramic substrate 1. The invention arranges a heat dissipation component to transfer the heat generated by the power chip when it is working to the heat dissipation base plate in a heat conduction manner through the double-sided copper-clad ceramic substrate 1, and the second electrode is transferred in a heat conduction manner through the double-sided copper-clad ceramic substrate 2, and the heat is insulated and dissipated from both sides of the power chip, thereby effectively reducing the thermal resistance of the power chip and increasing the power output capacity of the power chip.

Description

Technical Field

[0001] The present invention relates to the field of packaging technology, and more specifically, to a packaging structure of a power semiconductor packaging device. Background Art

[0002] Power semiconductor devices, also known as power electronic devices, are simply semiconductor devices that process power and have the ability to handle high voltage and high current, such as power chips. When power semiconductor devices are switched on and off, they will have serious heat dissipation problems, resulting in higher thermal resistance, higher temperatures, shorter service life, and even the burning of the chip.

[0003] In order to solve the heat dissipation problem of power devices (such as power chips), products in the prior art have introduced packaging solutions for surface mount devices (SMD devices) with pins, leading the power connection terminals from the bottom direction of the chip (or the collector direction) and directly mounting them on the PCB, thereby reducing the thermal resistance of the power device. However, this packaging method has only a single heat dissipation surface and can only be cooled by air, resulting in poor heat dissipation effect and failure to exert the power capacity of the power device.

[0004] Therefore, it is necessary to propose a packaging structure of a power semiconductor packaging device to at least partially solve the technical problem in the prior art that the heat dissipation efficiency of the power device is low due to the structure of a pinned surface mount device (SMD device). Summary of the invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0006] In order to at least partially solve the above problems, the present invention provides a packaging structure of a power semiconductor packaging device, comprising:

[0007] A plastic package body and a heat dissipation base plate partially embedded in the top of the plastic package body, wherein the plastic package body is encapsulated with a double-sided copper-clad ceramic substrate 1, a power chip, a metal heat conductive sheet, a double-sided copper-clad ceramic substrate 2 and a lead frame; a first electrode of the power chip is connected to the bottom of the heat dissipation base plate through the double-sided copper-clad ceramic substrate 1, a second electrode is connected to the double-sided copper-clad ceramic substrate 2 through the metal heat conductive sheet, and the lead frame is connected to the double-sided copper-clad ceramic substrate 1.

[0008] Preferably, a plurality of metal heat conducting plates are provided, and several of the metal heat conducting plates correspond to the power chip. One end of the metal heat conducting plate is connected to the power chip, and the other end is in contact with the second copper-clad ceramic substrate.

[0009] Preferably, two ends of the plurality of metal heat conducting plates are in contact with the first double-sided copper-clad ceramic substrate and the second double-sided copper-clad ceramic substrate respectively.

[0010] Preferably, the lead frame is partially encapsulated in a plastic package, and an extended section of the lead frame is arranged outside the plastic package.

[0011] Preferably, the upper and lower surfaces of the metal heat conductive sheet are provided with a welding layer or a sintering layer.

[0012] Preferably, the second electrode of the power chip is connected to the double-sided copper-clad ceramic substrate via a bonding wire.

[0013] Preferably, the metal heat conductive sheet is configured as a heat conductive copper sheet or a heat conductive molybdenum sheet.

[0014] Preferably, the plastic package body is made of epoxy resin EMC material.

[0015] Preferably, the top of the heat dissipation base plate is connected with air-cooling or water-cooling heat dissipation teeth.

[0016] Preferably, the bottom surface of the second double-sided copper-clad ceramic substrate exposes the plastic packaging body.

[0017] Preferably, the metal heat conductive sheet is configured as a cylindrical metal heat conductive sleeve, and a vertically arranged tensioning block is embedded in the metal heat conductive sleeve. There are multiple tensioning blocks, and the height of the tensioning blocks is equal to the height of the metal heat conductive sheet. The thermal expansion coefficient of the material of the tensioning blocks is smaller than the thermal expansion coefficient of the material of the metal heat conductive sleeve body.

[0018] Preferably, four tensioning blocks are provided, and the four tensioning blocks are evenly distributed on the outer wall of the metal heat-conducting sleeve body.

[0019] Preferably, four tensioning blocks are provided, and the four tensioning blocks are evenly distributed on the inner wall of the metal heat-conducting sleeve body.

[0020] Preferably, eight tensioning blocks are provided, four of which are evenly distributed on the inner wall of the metal heat-conducting sleeve body, and the remaining four tensioning blocks are evenly distributed on the outer wall of the metal heat-conducting sleeve body, and the tensioning blocks distributed on the inner wall of the metal heat-conducting sleeve body correspond one-to-one to the tensioning blocks distributed on the outer wall of the metal heat-conducting sleeve body.

[0021] Preferably, three tensioning blocks are provided, including a first tensioning block and a second tensioning block, the first tensioning block and the second tensioning block are both distributed on the outer wall of the metal heat-conducting sleeve body or are both distributed on the inner wall of the metal heat-conducting sleeve body, the two second tensioning blocks are symmetrically arranged on both sides of the second first tensioning block, and the length of the second tensioning block along the circumferential direction is equal to half the length of the first tensioning block along the circumferential direction.

[0022] Preferably, the packaging structure of the power semiconductor package device further includes a thermal balance component, and the thermal balance component includes:

[0023] Capillary tube 1 and capillary tube 2 are respectively arranged around double-sided copper-clad ceramic substrate 1 and double-sided copper-clad ceramic substrate 2; capillary tube 1 and capillary tube 2 are both connected to a heat balance box, and thermal expansion gas is contained in capillary tube 1 and capillary tube 2;

[0024] A side heat sink is connected to one side of the plastic package body, and an air-cooled or water-cooled heat sink is connected to the side heat sink. Capillary tube three is arranged in the side heat sink, and one end of capillary tube three is connected to the heat balance box, and the other end is connected to capillary tube one.

[0025] Preferably, the heat balance box comprises:

[0026] An upper cavity and a lower cavity, the upper cavity and the lower cavity are separated by a horizontal plate, a downwardly concave connecting hole is arranged at the center of the horizontal plate, the upper cavity is connected to the capillary tube 1, and the lower cavity is connected to the capillary tube 2;

[0027] An upper connecting pipe, which is arranged at the top of the upper cavity, has a conical opening at the bottom end, and a top end of the upper connecting pipe is connected to the capillary tube;

[0028] A column, the column is connected to the top of the upper cavity, and the bottom end of the column is connected to a piston plate;

[0029] Thermosensitive box, the thermosensitive box is sleeved at the bottom of the column, and a spring is arranged between the thermosensitive box and the top of the upper cavity, the spring is sleeved on the column, the piston plate is slidably connected in the thermosensitive box, the lower part of the thermosensitive box is filled with thermal expansion gas and is sealed by the piston plate;

[0030] A blocking block 1 is connected to the bottom end of the thermal box through a connecting rod 1, and the blocking block 1 is located above the communicating hole, and a gap is provided between the blocking block 1 and the communicating hole;

[0031] The second blocking block is connected to the side of the thermal box through the second connecting rod, and the second blocking block blocks the conical opening of the upper connecting pipe.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] The present invention provides a packaging structure of a power semiconductor packaging device. To solve the problem of poor heat dissipation of traditional surface mount devices (SMD devices), a heat dissipation component is set up to transfer the heat generated by a power chip when it is working. The first electrode transfers the heat to a heat dissipation base plate through a double-sided copper-clad ceramic substrate 1 by heat conduction, and dissipates it through air-cooled / water-cooled heat dissipation teeth. The second electrode transfers the heat through a double-sided copper-clad ceramic substrate 2 by heat conduction. Insulated heat dissipation can be performed from both sides of the power chip, thereby effectively reducing the thermal resistance of the power chip and increasing the power output capacity of the power chip.

[0034] The packaging structure of a power semiconductor packaging device described in the present invention, other advantages, objectives and features of the present invention will be partially reflected through the following description, and will also be partially understood by technicians in this field through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 A three-dimensional diagram of a power semiconductor package device of the present invention in a top view;

[0037] Figure 2 A three-dimensional diagram of a power semiconductor package device of the present invention when viewed from above;

[0038] Figure 3 A schematic diagram of the internal structure of a power semiconductor packaging device of the present invention;

[0039] Figure 4 This is a schematic diagram of the structure of the metal heat-conducting sleeve in Example 3 of the present invention;

[0040] Figure 5 This is a schematic diagram of the structure of the metal heat-conducting sleeve in Example 4 of the present invention;

[0041] Figure 6 This is a schematic structural diagram of a metal heat-conducting sleeve in Embodiment 5 of the present invention;

[0042] Figure 7 This is a schematic diagram of the structure of the metal heat-conducting sleeve in Example 6 of the present invention;

[0043] Figure 8 It is a schematic diagram of the structure of the heat balance component in the present invention;

[0044] Fig. 9 It is a schematic diagram of the cross-sectional structure of the heat balance box in the present invention;

[0045] Fig.10 It is a schematic cross-sectional structure diagram of the heat balance box in the present invention when the connecting hole is blocked.

[0046] In the figure: 1. plastic package; 2. double-sided copper-clad ceramic substrate 1; 3. heat dissipation base plate; 4. lead frame; 5. double-sided copper-clad ceramic substrate 2; 6. power chip; 7. welding layer; 8. metal thermal conductive sheet; 9. bonding wire; 11. metal thermal conductive sleeve; 12. tensioning block; 13. first tensioning block; 14. second tensioning block; 21. capillary 1; 22. capillary 2; 23. thermal balance box; 24. capillary 3; 25. upper cavity; 26. lower cavity; 27. horizontal plate; 28. connecting hole; 29. ​​upper connecting pipe; 30. column; 31. piston plate; 32. thermal sensitive box; 33. blocking block 1; 34. connecting rod 1; 35. blocking block 2; 36. connecting rod 2. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0048] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0049] Embodiment 1:

[0050] like Figure 1-3 As shown, the present invention provides a packaging structure of a power semiconductor packaging device, comprising:

[0051] A plastic package body 1 and a heat dissipation base plate 3 partially embedded in the top of the plastic package body 1, wherein the plastic package body 1 encapsulates a double-sided copper-clad ceramic substrate 1 2, a power chip 6, a metal thermal conductive sheet 8, a double-sided copper-clad ceramic substrate 2 5 and a lead frame 4; a first electrode of the power chip 6 is connected to the bottom of the heat dissipation base plate 3 through the double-sided copper-clad ceramic substrate 1 2, a second electrode is connected to the double-sided copper-clad ceramic substrate 2 5 through the metal thermal conductive sheet 8, and the lead frame 4 is connected to the double-sided copper-clad ceramic substrate 1 2.

[0052] The plastic package body 1 is made of epoxy resin EMC material.

[0053] The second electrode of the power chip 6 is connected to the double-sided copper-clad ceramic substrate 2 through a bonding wire 9 .

[0054] The metal heat conductive sheet 8 is configured as a heat conductive copper sheet or a heat conductive molybdenum sheet.

[0055] The top of the heat dissipation base plate 3 is connected with air-cooling or water-cooling heat dissipation teeth.

[0056] The lead frame 4 is partially encapsulated in the plastic package 1 , and an extended section of the lead frame 4 is arranged outside the plastic package 1 .

[0057] The bottom surface of the double-sided copper-clad ceramic substrate 5 exposes the plastic package body 1 .

[0058] The working principle and beneficial effects of the above technical solution are:

[0059] A packaging structure of a power semiconductor packaging device, wherein a plastic package body 1 adopts materials used for packaging semiconductor devices in the prior art, for example, a packaging medium made of epoxy resin EMC. The plastic package body 1 contains a double-sided copper-clad ceramic substrate 1 2, a power chip 6, a metal heat conductive sheet 8, a double-sided copper-clad ceramic substrate 2 5, and a lead frame 4. The power chip 6 can be connected to the metal heat conductive sheet 8 and contact the heat dissipation base plate 3. When the device is working, the power chip 6 generates heat, and the first electrode of the power chip 6 is connected to the heat dissipation base plate through the double-sided copper-clad ceramic substrate 1 2, and the second electrode is connected to the double-sided copper-clad ceramic substrate 2 5 through the metal heat conductive sheet 8. Heat can be dissipated from both sides of the power chip 6.

[0060] Through the above structural design, the present invention aims at the problem of poor heat dissipation of traditional surface mount devices (SMD devices). By setting a heat dissipation component, the heat generated by the power chip 6 when working is transferred to the heat dissipation base plate 3 by heat conduction through the double-sided copper-clad ceramic substrate 1 2 at the first electrode, and dissipated through the air-cooled / water-cooled heat dissipation teeth. The second electrode is transferred through the double-sided copper-clad ceramic substrate 2 5 by heat conduction. Insulated heat dissipation can be performed from both sides of the power chip 6, thereby effectively reducing the thermal resistance of the power chip 6 and increasing the power output capacity of the power chip 6.

[0061] Based on the above embodiment 1, a plurality of metal heat conductive sheets 8 are provided, and several metal heat conductive sheets 8 correspond to the power chip 6 . One end of the metal heat conductive sheet 8 is connected to the power chip 6 , and the other end is in contact with the double-sided copper-clad ceramic substrate 2 5 .

[0062] Two ends of a plurality of metal heat conducting sheets 8 are in contact with the double-sided copper-clad ceramic substrate 1 2 and the double-sided copper-clad ceramic substrate 2 5 respectively.

[0063] The metal heat conducting sheet 8 can simultaneously realize heat conduction between the power chip 6 and the double-sided copper-clad ceramic substrate 2 5 , and heat conduction between the double-sided copper-clad ceramic substrate 1 2 and the double-sided copper-clad ceramic substrate 2 5 , thereby improving the uniformity of heat distribution inside the packaging structure.

[0064] On the basis of the above-mentioned embodiment 1, the upper and lower surfaces of the metal thermal conductive sheet 8 are provided with a welding layer 7 or a sintering layer, which is used to fix the metal thermal conductive sheet 8 to the bottom surface of the double-sided copper-clad ceramic substrate 1 2, the metal thermal conductive sheet 8 to the top surface of the double-sided copper-clad ceramic substrate 2 5, and the metal thermal conductive sheet 8 to the power chip 6.

[0065] Embodiment 2:

[0066] like Figure 4-7As shown, on the basis of the above-mentioned embodiment 1, the metal heat-conducting sheet 8 is configured as a cylindrical metal heat-conducting sleeve 11, and a vertically arranged tensioning block 12 is embedded in the metal heat-conducting sleeve 11. The tensioning block 12 is provided in plurality, and the height of the tensioning block 12 is equal to the height of the metal heat-conducting sheet 8. The thermal expansion coefficient of the material of the tensioning block 12 is smaller than the thermal expansion coefficient of the material of the main body of the metal heat-conducting sleeve 11.

[0067] The working principle and beneficial effects of the above technical solution are:

[0068] The double-sided copper-clad ceramic substrate 1 2 and the double-sided copper-clad ceramic substrate 2 5 are connected by a metal heat conductive sheet 8, which contacts the high-temperature resin when the structure is plastic-sealed. The metal heat conductive sheet 8 is in a high-temperature state and is easily deformed by the pressure of the resin, resulting in the displacement of the packaging position of the double-sided copper-clad ceramic substrate 1 2 and the double-sided copper-clad ceramic substrate 2 5, affecting the heat dissipation effect. A cylindrical metal heat conductive sleeve 11 is set on the metal heat conductive sheet 8. When the metal heat conductive sleeve 11 has a tendency to deform, since the thermal expansion coefficient of the tensioning block 12 is less than the thermal expansion coefficient of the material of the main body of the metal heat conductive sleeve 11, the thermal deformation generated is relatively small. The metal heat conductive sleeve 11 is tensioned to increase the vertical stiffness of the metal heat conductive sheet 8, reduce deformation during the plastic sealing process, and then reduce the position displacement of the double-sided copper-clad ceramic substrate, ensuring product quality and heat dissipation effect.

[0069] Embodiment 3:

[0070] like Figure 4 As shown, on the basis of the above-mentioned embodiment 2, four tensioning blocks 12 are provided, and the four tensioning blocks 12 are evenly distributed on the outer wall of the main body of the metal heat-conducting sleeve 11 .

[0071] The working principle and beneficial effects of the above technical solution are:

[0072] The four tensioning blocks 12 are evenly distributed on the outer wall of the main body of the metal heat-conducting sleeve 11, and generate uniform tensioning force when deformed by heat. The four tensioning blocks 12 cooperate with each other to reduce the deformation of the main body of the metal heat-conducting sleeve 11 and avoid self-bending.

[0073] Embodiment 4:

[0074] like Figure 5 As shown, on the basis of the above-mentioned embodiment 2, four tensioning blocks 12 are provided, and the four tensioning blocks 12 are evenly distributed on the inner wall of the main body of the metal heat-conducting sleeve 11 .

[0075] The working principle and beneficial effects of the above technical solution are:

[0076] The four tensioning blocks 12 are evenly distributed on the inner wall of the main body of the metal heat-conducting sleeve 11, and generate uniform tensioning force when deformed by heat. The four tensioning blocks 12 cooperate with each other to reduce the deformation of the main body of the metal heat-conducting sleeve 11 and avoid self-bending.

[0077] Embodiment 5:

[0078] like Figure 6 As shown, on the basis of the above-mentioned embodiment 2, eight tensioning blocks 12 are set, four tensioning blocks 12 are evenly distributed on the inner wall of the metal heat-conducting sleeve 11 body, and the remaining four tensioning blocks 12 are evenly distributed on the outer wall of the metal heat-conducting sleeve 11 body, and the tensioning blocks 12 distributed on the inner wall of the metal heat-conducting sleeve 11 body correspond one to one with the tensioning blocks 12 distributed on the outer wall of the metal heat-conducting sleeve 11 body.

[0079] The working principle and beneficial effects of the above technical solution are:

[0080] Tensioning blocks 12 are correspondingly arranged on the inner wall and the outer wall of the main body of the metal heat-conducting sleeve 11 to generate uniform tensioning force when deformed by heat. The cooperation of multiple tensioning blocks 12 can reduce the deformation of the main body of the metal heat-conducting sleeve 11, avoid bending of the metal heat-conducting sleeve 11 due to uneven force on the left and right sides, and avoid uneven force on the inside and outside of the metal heat-conducting sleeve 11, which may cause separation at the connection between the upper and lower ends.

[0081] Embodiment 6:

[0082] like Figure 7 As shown, on the basis of the above-mentioned embodiment 2, three tensioning blocks 12 are set, and the three tensioning blocks 12 include a first tensioning block 13 and a second tensioning block 14. The first tensioning block 13 and the second tensioning block 14 are both distributed on the outer wall of the metal heat-conducting sleeve 11 body or are both distributed on the inner wall of the metal heat-conducting sleeve 11 body. The two second tensioning blocks 14 are symmetrically arranged on both sides of the second first tensioning block 13, and the length of the second tensioning block 14 along the circumferential direction is equal to half of the length of the first tensioning block 13 along the circumferential direction.

[0083] The working principle and beneficial effects of the above technical solution are:

[0084] The number of tensioning blocks 12 is three, and the deformation of the metal heat-conducting sleeve 11 is reduced through the cooperation of the first tensioning block 13 and the two second tensioning blocks 14. The length of the second tensioning block 14 along the circumferential direction is equal to half of the length of the first tensioning block 13 along the circumferential direction, which can balance the deformation of each tensioning block 14 and avoid self-bending. When the metal heat-conducting sleeve 11 and the tensioning block 12 are formed, it is only necessary to ensure that the distance between the two second tensioning blocks 14 and the first tensioning block 13 is equal, and the specific size is not limited, thereby reducing the processing difficulty.

[0085] Embodiment 7:

[0086] like Figure 8-10 As shown, based on the above-mentioned embodiment 1, the packaging structure of a power semiconductor packaging device further includes a thermal balance component, and the thermal balance component includes:

[0087] Capillary 1 21 and capillary 2 22, capillary 1 21 and capillary 2 22 are respectively arranged around double-sided copper-clad ceramic substrate 1 2 and double-sided copper-clad ceramic substrate 2 5; capillary 1 21 and capillary 2 22 are both connected to the heat balance box 23, and thermal expansion gas is contained in capillary 1 21 and capillary 2 22;

[0088] A side heat sink is connected to one side of the plastic package body 1, and an air-cooled or water-cooled heat sink is connected to the side heat sink. A capillary tube 3 24 is arranged in the side heat sink, and one end of the capillary tube 3 24 is connected to the heat balance box 23, and the other end is connected to the capillary tube 1 21.

[0089] The heat balance box 23 comprises:

[0090] The upper cavity 25 and the lower cavity 26 are separated by a transverse plate 27. A downwardly concave communicating hole 28 is provided at the center of the transverse plate 27. The upper cavity 25 is connected to the capillary tube 1 21, and the lower cavity 26 is connected to the capillary tube 2 22.

[0091] The upper connecting pipe 29 is arranged at the top of the upper cavity 25, the bottom of the upper connecting pipe 29 is provided with a tapered opening, and the top of the upper connecting pipe 29 is connected to the capillary tube 3 24;

[0092] A column 30, the column 30 is connected to the top of the upper cavity 25, and a piston plate 31 is connected to the bottom end of the column 30;

[0093] Thermosensitive box 32, the thermosensitive box 32 is sleeved at the bottom end of the column 30, and a spring is provided between the thermosensitive box 32 and the top of the upper cavity 25, the spring is sleeved on the column 30, the piston plate 31 is slidably connected in the thermosensitive box 32, the lower part of the thermosensitive box 32 is filled with thermal expansion gas and is sealed by the piston plate 31;

[0094] A blocking block 33, the blocking block 33 is connected to the bottom end of the thermal box 32 through a connecting rod 34, the blocking block 33 is located above the connecting hole 28, and a gap is provided between the blocking block 33 and the connecting hole 28;

[0095] The second blocking block 35 is connected to the side of the thermosensitive box 32 through the second connecting rod 36 , and the second blocking block 35 blocks the conical opening of the upper connecting pipe 29 .

[0096] The working principle and beneficial effects of the above technical solution are:

[0097] When the packaging structure is used, both the double-sided copper-clad ceramic substrate 1 2 and the double-sided copper-clad ceramic substrate 2 5 receive the heat generated by the power chip 6. Due to the different heat dissipation areas and heat dissipation structures of the two, the phenomenon of uneven heat on the upper and lower sides of the power chip 6 will occur. By setting a heat balance component, the heat-expanding gas in the capillary 1 21 absorbs the heat on the double-sided copper-clad ceramic substrate 1 2 to increase the temperature, and the heat-expanding gas in the capillary 2 22 absorbs the heat on the double-sided copper-clad ceramic substrate 2 5 to increase the temperature. When the temperatures of the two are inconsistent, the heat-expanding gas flows in the capillary 1 21, the capillary 2 22 and the heat balance box 23, so that the temperature of the heat-expanding gas is consistent after mixing, and the heat balance of the double-sided copper-clad ceramic substrate 1 2 and the double-sided copper-clad ceramic substrate 2 5 is maintained. When the heat-expanding gas flows, it passes through the gap between the blocking block 1 33 and the connecting hole 28. When the temperature of the thermal expansion gas in the capillary tube and the upper cavity 25 rises to a preset temperature, the thermal expansion gas in the thermal box 32 absorbs heat and expands, so that the lower space of the thermal box 32 increases, and the piston plate 31 slides along the inner wall of the thermal box 32, so that the blocking block 2 35 moves away from the upper connecting pipe 29, and the capillary tube 3 24 is connected with the heat balance box 23. At the same time, the blocking block 1 33 moves downward to block the connecting hole 28; the thermal expansion gas in the capillary tube 1 21 enters the upper cavity 25, diffuses to the capillary tube 3 through the upper connecting pipe 29, and then flows into the capillary tube 3. 24, enters the side heat sink for cooling and mixes with the low-temperature thermal expansion gas in the capillary three 24, and diffuses into the capillary one 21 again, so that the temperature in the capillary one 21 and the upper cavity 25 is reduced. When it is reduced to a preset temperature, the temperature of the thermal expansion gas in the thermistor box 32 is reduced, and the lower space is reduced, so that the blocking block 35 blocks the upper connecting pipe 29 again, the blocking block one 33 is separated from the connecting hole 28, and the capillary one 21 and the capillary two 22 are reconnected, so that the high-temperature and low-temperature thermal expansion gases are diffused and mixed.

[0098] Through the above structural design, the capillary 1 21 and the capillary 2 22 are connected to effectively achieve the balance optimization of the heat between the double-sided copper-clad ceramic substrate 1 2 and the double-sided copper-clad ceramic substrate 2 5, so that the temperatures of the two are similar, and when the temperature exceeds the preset value, the heat is transferred to the side heat sink for supplementary heat dissipation, thereby improving the heat dissipation capacity of the packaging structure; when supplementing the heat dissipation, a step-by-step heat dissipation method is adopted in which the capillary 1 21 dissipates heat and the capillary 2 22 dissipates heat again after the capillary 1 21 dissipates heat, thereby reducing the amount of thermal expansion gas in a single heat dissipation and achieving a better heat dissipation effect.

[0099] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0100] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0101] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A packaging structure of a power semiconductor packaging device, characterized in that: include: A plastic package (1) and a heat dissipation base plate (3) partially embedded in the top of the plastic package (1); the plastic package (1) encapsulates a double-sided copper-clad ceramic substrate (2), a power chip (6), a metal heat conductive sheet (8), a double-sided copper-clad ceramic substrate (5) and a lead frame (4); the first electrode of the power chip (6) is connected to the bottom of the heat dissipation base plate (3) through the double-sided copper-clad ceramic substrate (2), the second electrode is connected to the double-sided copper-clad ceramic substrate (5) through the metal heat conductive sheet (8), and the lead frame (4) is connected to the double-sided copper-clad ceramic substrate (2); The metal heat conductive sheet (8) is arranged as a cylindrical metal heat conductive sleeve (11), and a vertically arranged tension block (12) is embedded in the metal heat conductive sleeve (11). A plurality of tension blocks (12) are arranged, and the height of the tension blocks (12) is equal to the height of the metal heat conductive sheet (8). The thermal expansion coefficient of the material of the tension blocks (12) is smaller than the thermal expansion coefficient of the material of the main body of the metal heat conductive sleeve (11).

2. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: A plurality of metal heat conducting sheets (8) are provided, and a plurality of metal heat conducting sheets (8) correspond to the power chip (6). One end of the metal heat conducting sheet (8) is connected to the power chip (6), and the other end is in contact with the second copper-clad ceramic substrate (5).

3. The packaging structure of a power semiconductor packaging device according to claim 2, characterized in that: Two ends of a plurality of metal heat conducting sheets (8) are in contact with a first double-sided copper-clad ceramic substrate (2) and a second double-sided copper-clad ceramic substrate (5) respectively.

4. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: The lead frame (4) is partially encapsulated in the plastic package (1), and an extended section of the lead frame (4) is arranged outside the plastic package (1).

5. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: The upper and lower surfaces of the metal heat conducting sheet (8) are provided with a welding layer (7) or a sintering layer.

6. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: The second electrode of the power chip (6) is connected to the double-sided copper-clad ceramic substrate (2) via a bonding wire (9).

7. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: The metal heat-conducting sheet (8) is configured as a heat-conducting copper sheet or a heat-conducting molybdenum sheet.

8. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: The plastic package (1) is made of epoxy resin EMC material.

9. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: The top of the heat dissipation base plate (3) is connected with air-cooling or water-cooling heat dissipation teeth.

10. The packaging structure of a power semiconductor packaging device according to claim 1, characterized in that: The bottom surface of the second double-sided copper-clad ceramic substrate (5) exposes the plastic package body (1).

Images