IGBT module packaging structure based on ceramic substrate

Abstract

The utility model discloses an IGBT (Insulated Gate Bipolar Translator) module packaging structure based on a ceramic substrate, and aims to solve the problems that a bonding wire for traditional packaging is easy to lose efficacy, poor in heat dissipation and the like. The structure is based on a heat dissipation bottom plate and is provided with a shell and a terminal, a multi-layer structure is sequentially arranged on the heat dissipation bottom plate, the key point is that a metal copper sheet is introduced and is connected with an IGBT chip, the terminal and an upper copper layer through a welding layer, bonding wires are replaced to achieve electrical connection, the bearing capacity is high, and aging is not prone to occurring. Meanwhile, a plurality of heat dissipation gaps are elaborately designed and filled with heat conduction gel, and a high-efficiency heat dissipation path is constructed in cooperation with the large heat dissipation specific surface area of the metal copper sheet, so that double-face heat dissipation is achieved. And a mirror symmetry structure expansion function is also provided, all parts cooperate, the reliability and applicability of the module are improved, and the complex electrical application requirements are met.

Description

TECHNICAL FIELD

[0001] The utility model relates to a semiconductor packaging technical field especially, it relates to a kind of IGBT module packaging structure based on ceramic substrate. BACKGROUND

[0002] Traditional IGBT module packaging is layered structure, from heat transfer path main component is chip, solder, upper copper layer, ceramic substrate, lower copper layer, DBC solder and heat dissipation bottom plate in turn, and using bonding wire as the electrical connection between IGBT module chip and ceramic copper clad plate (Direct Bonding Copper,DBC) and copper plate and module terminal, simultaneously through heat-conducting gel to assist heat dissipation and protect chip and bonding wire.

[0003] However, traditional IGBT module packaging structure has many shortcomings. Since adopting bonding wire as electrical connection, the thermal expansion coefficient of bonding wire and module chip is different due to different materials, and the temperature and stress borne by the bonding place of bonding wire and chip are maximum, and long-term stress fluctuation is prone to cause fatigue cumulative damage, thereby causing bonding drop-out failure, and too large junction temperature fluctuation will also cause bonding wire fatigue accumulation to accelerate. Once module has a bonding wire drop-out failure, IGBT module will increase the current transmitted to other bonding wires, cause the temperature of remaining bonding wire to increase and the stress to increase, promote remaining bonding wire to further age failure, finally lead to IGBT module failure. In addition, compared with the metal copper sheet introduced in new scheme, bonding wire is small in volume, limited in carrying voltage and current capacity, small in specific surface area of heat dissipation, poor in heat dissipation capacity, difficult to meet the demand of high-efficiency heat dissipation, limit the overall performance improvement of IGBT module. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of IGBT module packaging structure based on ceramic substrate, to solve the problem that traditional IGBT module packaging is prone to fatigue drop-out due to bonding wire, poor in carrying electrical performance and poor in heat dissipation, leading to module failure, overall performance is limited.

[0005] The utility model realizes by the following technical scheme:

[0006] The application discloses a ceramic substrate-based IGBT module packaging structure, which comprises a heat dissipation base plate, a shell arranged on the heat dissipation base plate, and a first terminal arranged on one side of the shell; in the direction from the heat dissipation base plate to the shell, the heat dissipation base plate is sequentially provided with a first welding layer, a first lower copper layer, a first ceramic substrate, a first upper copper layer, a second welding layer and an IGBT chip; the ceramic substrate-based IGBT module packaging structure further comprises a first metal copper sheet, a third welding layer, a fourth welding layer and a fifth welding layer; one end of the third welding layer is connected to the IGBT chip, and the other end of the third welding layer is connected to the first metal copper sheet; one end of the fourth welding layer is connected to the first terminal, and the other end of the fourth welding layer is connected to the first metal copper sheet; one end of the fifth welding layer is connected to the first upper copper layer, and the other end of the fifth welding layer is connected to the first metal copper sheet.

[0007] Preferably, a heat dissipation gap is left between the first metal copper sheet and the first terminal, and heat dissipation gaps are left between the fifth welding layer and the second welding layer, the IGBT chip, the third welding layer and the fourth welding layer respectively; the heat dissipation gaps are filled with heat-conducting gel.

[0008] Preferably, in the direction from the heat dissipation base plate to the shell, the vertical distance from the upper wall of the first metal copper sheet to the heat dissipation base plate is L1, the vertical distance from the upper surface of the heat-conducting gel to the heat dissipation base plate is L2, and L1 < L2 is satisfied.

[0009] Preferably, the first terminal comprises a vertical section and a parallel section which are connected to each other perpendicularly, and the shell is provided with a notch which matches the shapes of the vertical section and the parallel section.

[0010] Preferably, in the direction from the heat dissipation base plate to the shell, the vertical distance from the upper end of the vertical section to the parallel section is L3, the vertical distance from the upper surface of the first metal copper sheet to the parallel section is L4, and L3 > L4 is satisfied.

[0011] Preferably, the heat dissipation base plate is further sequentially provided with a sixth welding layer, a second lower copper layer, a second ceramic substrate, a second upper copper layer, a seventh welding layer, an FRD chip, an eighth welding layer, a ninth welding layer, a tenth welding layer, a second metal copper sheet and a second terminal.

[0012] The sixth welding layer is mirror-symmetrical to the first welding layer, the second lower copper layer is mirror-symmetrical to the first lower copper layer, the second ceramic substrate is mirror-symmetrical to the first ceramic substrate, the second upper copper layer is mirror-symmetrical to the first upper copper layer, and the seventh welding layer is mirror-symmetrical to the second welding layer.

[0013] One end of the eighth solder layer is connected to the FRD chip, and the other end of the eighth solder layer is connected to the second metal copper sheet; one end of the ninth solder layer is connected to the second terminal, and the other end of the ninth solder layer is connected to the second metal copper sheet; one end of the tenth solder layer is connected to the second upper copper layer, and the other end of the tenth solder layer is connected to the second metal copper sheet.

[0014] Preferably, a heat dissipation gap is left between the second metal copper sheet and the second terminal, and heat dissipation gaps are respectively left between the tenth solder layer and the seventh solder layer, the FRD chip, the eighth solder layer and the ninth solder layer; a heat dissipation gap is left between the IGBT chip and the FRD chip; and the heat dissipation gaps are all filled with heat-conducting gel.

[0015] Preferably, a heat dissipation gap is left between the first metal copper sheet and the second metal copper sheet, a heat dissipation gap is left between the third solder layer and the eighth solder layer, a heat dissipation gap is left between the IGBT chip and the FRD chip, a heat dissipation gap is left between the second solder layer and the seventh solder layer, a heat dissipation gap is left between the first upper copper layer and the second upper copper layer, a heat dissipation gap is left between the first ceramic substrate and the second ceramic substrate, a heat dissipation gap is left between the first lower copper layer and the second lower copper layer, and a heat dissipation gap is left between the first solder layer and the sixth solder layer; and the heat dissipation gaps are all filled with heat-conducting gel.

[0016] Preferably, a first notch is arranged on the first metal copper sheet, one end of the third solder layer is connected to the outer wall of the notch, and the other end of the third solder layer is connected to the IGBT chip.

[0017] Preferably, a second notch is arranged on the second metal copper sheet, one end of the eighth solder layer is connected to the outer wall of the second notch, and the other end of the eighth solder layer is connected to the FRD chip.

[0018] Compared with the prior art, the utility model has the advantages and beneficial effects that in actual use scene, the utility model is based on the heat dissipation base plate, and the layers are orderly arranged, and the key is to introduce the first metal copper sheet and connect the chip, the terminal and the upper copper layer through the solder layer. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings described herein are used to provide further understanding of the embodiments of the present application, form a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0020] Figure 1 It is a schematic diagram of the existing packaging structure, which aims to show the connection relationship of the bonding wire;

[0021] Figure 2 It is a schematic diagram of the overall packaging structure of the present application.

[0022] The represented by the reference signs are:

[0023] 10, heat dissipation bottom plate, 11, shell, 12, first terminal, 121, second terminal,

[0024] 13, first solder layer, 14, first lower copper layer, 15, first ceramic substrate, 16, first upper copper layer, 17, second solder layer, 18, IGBT chip, 19, third solder layer,

[0025] 20, fifth solder layer, 21, fourth solder layer, 22, first metal copper sheet, 23, sixth solder layer, 24, second lower copper layer, 25, second ceramic substrate, 26, second upper copper layer, 27, seventh solder layer, 28, FRD chip, 29, eighth solder layer,

[0026] 30, tenth solder layer, 31, ninth solder layer, 32, second metal copper sheet, 33, heat-conducting gel. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the usual meaning understood by those skilled in the art to which the present application belongs. The "first", "second" and similar words used in the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Include" or "contain" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0028] The traditional IGBT module packaging relies on bonding wires for electrical connection, which brings a lot of trouble. On the one hand, the thermal expansion coefficient of the bonding wire is different from that of the chip, the bonding place is greatly impacted by temperature and pressure, and stress fluctuation makes it easy to accumulate fatigue and fall off, and a single fall-off will also involve the remaining bonding wires, accelerating the overall aging failure.

[0029] Example 1:

[0030] like Figure 1 The diagram shows a traditional IGBT module packaging structure. Because it uses bonding wires for electrical connection, the coefficients of thermal expansion of the bonding wires and the module chip differ depending on the materials. Furthermore, the bonding area between the bonding wire and the chip experiences the highest temperature and stress. Long-term stress fluctuations can easily lead to fatigue accumulation and damage, resulting in bond detachment failure. Excessive junction temperature fluctuations also accelerate bond wire fatigue accumulation. Once one bonding wire detaches, the IGBT module will increase the current transmitted to the remaining bonding wires, causing increased temperature and stress on the remaining bonding wires, accelerating their aging and ultimately leading to IGBT module failure.

[0031] like Figure 2 As shown in the embodiment of this solution, an IGBT module packaging structure based on a ceramic substrate is provided, including a heat dissipation base plate 10, a housing 11 on the heat dissipation base plate 10, a first terminal 12 on one side of the housing 11, and along the direction from the heat dissipation base plate 10 to the housing 11, a first solder layer 13, a first lower copper layer 14, a first ceramic substrate 15, a first upper copper layer 16, a second solder layer 17, and an IGBT chip 18 are also sequentially provided on the heat dissipation base plate 10. The IGBT module packaging structure based on a ceramic substrate also includes a first copper sheet 22, a third solder layer 19, a fourth solder layer 21, and a fifth solder layer 20. One end of the third solder layer 19 is connected to the IGBT chip 18, and the other end of the third solder layer 19 is connected to the first copper sheet 22; one end of the fourth solder layer 21 is connected to the first terminal 12, and the other end of the fourth solder layer 21 is connected to the first copper sheet 22; one end of the fifth solder layer 20 is connected to the first upper copper layer 16, and the other end of the fifth solder layer 20 is connected to the first copper sheet 22.

[0032] This solution aims to address the issues of low reliability and limited performance in traditional IGBT module packaging caused by the easy failure of bonding wires and poor heat dissipation. Based on a heat sink 10, the housing 11 on top provides protection, and the first terminal 12 is used for external circuitry. Key components, such as the copper sheet, are connected to the IGBT chip 18 via solder layers, ensuring electrical transmission. Compared to bonding wires, this solder layer can withstand higher voltage and current, and greater stress, reducing the risk of failure due to electrical connection component malfunctions. The solder layer connects to the first terminal 12, enabling circuit expansion; and the solder layer connects to the upper copper layer, optimizing the current conduction path. In practical applications, all components work together, utilizing the large heat dissipation surface area of ​​the copper sheet, combined with the thermally conductive gel 33 in the heat dissipation gap, to effectively improve heat dissipation efficiency and ensure stable and efficient operation of the IGBT module.

[0033] In this embodiment, a heat dissipation gap is left between the first copper sheet 22 and the first terminal 12, and a heat dissipation gap is left between the fifth solder layer 20 and the second solder layer 17, the IGBT chip 18, the third solder layer 19 and the fourth solder layer 21 respectively; the heat dissipation gaps are filled with heat-conducting gel 33.

[0034] The heat dissipation gaps provide space channels for heat dissipation, so that heat does not excessively accumulate in the areas where the two are in close contact. Similarly, the heat dissipation gaps between the fifth solder layer 20 and the second solder layer 17, the IGBT chip 18, the third solder layer 19 and the fourth solder layer 21 ensure that the heat generated by each component during operation can be dissipated in time. The heat-conducting gel 33 filled in these heat dissipation gaps can quickly conduct heat away due to its good heat-conducting performance, further improving the heat dissipation effect.

[0035] In this embodiment, along the direction from the heat dissipation base plate 10 to the shell 11, the vertical distance from the upper wall of the first copper sheet 22 to the heat dissipation base plate 10 is L1, and the vertical distance from the upper surface of the heat-conducting gel 33 to the heat dissipation base plate 10 is L2, and L1 < L2 is satisfied.

[0036] The heat dissipation path is finely planned in terms of spatial layout. This enables the heat-conducting gel 33 to better cover the key heat generating areas, fully exerting its heat-conducting and heat-dissipating functions, guiding heat to be transferred in a direction more conducive to dissipation, while avoiding the copper sheet prematurely dissipating heat to the surrounding space which may not be conducive to the overall heat dissipation layout, optimizing the heat transfer process within the module and enhancing the overall heat dissipation efficiency.

[0037] In this embodiment, the first terminal 12 includes a vertical section and a parallel section connected perpendicularly to each other, and the shell 11 is provided with a notch matching the shapes of the vertical section and the parallel section.

[0038] On the one hand, such a terminal structure facilitates precise connection with external devices during actual installation and connection of external lines, improves the stability and reliability of the connection, and reduces the risk of electrical failure caused by loose connection; on the other hand, the notch design matching the shape of the shell 11 makes the layout of the terminal within the shell 11 more reasonable and compact, saving space while ensuring the regularity of the internal structure of the module, facilitating the collaborative work of the components and improving the integration and practicality of the entire IGBT module.

[0039] In this embodiment, along the direction from the heat dissipation base plate 10 to the shell 11, the vertical distance from the upper end of the vertical section to the parallel section is L3, and the vertical distance from the upper surface of the first copper sheet 22 to the parallel section is L4, and L3 > L4 is satisfied.

[0040] On one hand, the larger L3 distance provides more abundant operation space for external line connection to the terminal vertical section, facilitating installation and maintenance; on the other hand, the relatively smaller L4 distance ensures that the metal copper sheet is in a reasonable heat dissipation position in the overall structure, so that it can efficiently receive heat from various components and dissipate it, optimizing the internal heat distribution of the module and improving the synergy of heat dissipation and electrical connection.

[0041] In this embodiment, the heat dissipation bottom plate 10 is further sequentially provided with a sixth solder layer 23, a second lower copper layer 24, a second ceramic substrate 25, a second upper copper layer 26, a seventh solder layer 27, an FRD chip 28, an eighth solder layer 29, a ninth solder layer 31, a tenth solder layer 30, a second metal copper sheet 32 and a second terminal 121; wherein the sixth solder layer 23 is mirror-symmetric to the first solder layer 13, the second lower copper layer 24 is mirror-symmetric to the first lower copper layer 14, the second ceramic substrate 25 is mirror-symmetric to the first ceramic substrate 15, the second upper copper layer 26 is mirror-symmetric to the first upper copper layer 16, and the seventh solder layer 27 is mirror-symmetric to the second solder layer 17; one end of the eighth solder layer 29 is connected to the FRD chip 28, and the other end of the eighth solder layer 29 is connected to the second metal copper sheet 32; one end of the ninth solder layer 31 is connected to the second terminal 121, and the other end of the ninth solder layer 31 is connected to the second metal copper sheet 32; one end of the tenth solder layer 30 is connected to the second upper copper layer 26, and the other end of the tenth solder layer 30 is connected to the second metal copper sheet 32.

[0042] The sixth solder layer 23 is symmetrically arranged with the first solder layer 13, the second lower copper layer 24 is corresponding to the first lower copper layer 14, and so on for the symmetric components, which together constitute a functionally complete expansion module. Taking the sixth solder layer 23 as an example, it cooperates with the first solder layer 13 to stably connect the components below and ensure the uniformity of heat and current conduction; the second lower copper layer 24 and the first lower copper layer 14 are symmetrically arranged to strengthen the stability of the overall structure and provide balanced support for the components above; the FRD chip cooperates with the IGBT chip 18 to meet different working condition requirements. The symmetric components are connected to the second metal copper sheet 32 and the second terminal 121 through the corresponding solder layers, expanding the module functions and realizing multi-line connection and complex working condition response.

[0043] In this embodiment, a heat dissipation gap is left between the second metal copper sheet 32 and the second terminal 121, and heat dissipation gaps are left between the tenth solder layer 30 and the seventh solder layer 27, the FRD chip 28, the eighth solder layer 29 and the ninth solder layer 31 respectively; a heat dissipation gap is left between the IGBT chip 18 and the FRD chip 28; heat-conducting gel 33 is filled in all the heat dissipation gaps.

[0044] The heat dissipation gaps provide channels for heat dissipation and avoid heat accumulation due to close contact. The heat dissipation gaps between the tenth solder layer 30 and the seventh solder layer 27, the FRD chip, the eighth solder layer 29, and the ninth solder layer 31 ensure timely heat dissipation and protect the components. The heat dissipation gap between the IGBT chip 18 and the FRD chip is particularly important, as both generate a large amount of heat during operation. The gap and the filled heat-conducting gel 33 can effectively balance the heat and prevent thermal interference, thereby improving the overall heat dissipation efficiency.

[0045] In this embodiment, heat dissipation gaps are left between the first metal copper sheet 22 and the second metal copper sheet 32, between the third solder layer 19 and the eighth solder layer 29, between the IGBT chip 18 and the FRD chip 28, between the second solder layer 17 and the seventh solder layer 27, between the first upper copper layer 16 and the second upper copper layer 26, between the first ceramic substrate 15 and the second ceramic substrate 25, between the first lower copper layer 14 and the second lower copper layer 24, and between the first solder layer 13 and the sixth solder layer 23. Heat-conducting gel 33 is filled in the heat dissipation gaps.

[0046] After filling the gaps with heat-conducting gel 33, a three-dimensional heat dissipation network is formed, ensuring smooth heat transfer and dissipation in all corners of the module, and preventing local overheating from causing performance degradation or failure of components.

[0047] Embodiment 2:

[0048] In this embodiment, the first metal copper sheet 22 is provided with a first slot, one end of the third solder layer 19 is connected to the outer wall of the slot, and the other end of the third solder layer 19 is connected to the IGBT chip 18. The presence of the slot changes the connection path of the solder layer, optimizes the stress distribution, avoids stress concentration points caused by direct connection, improves the connection reliability, and facilitates the filling of solder layer materials, enhances the stability of electrical connection, ensures stable transmission of current from the chip to the metal copper sheet through the solder layer, and improves the overall electrical performance.

[0049] In this embodiment, the second metal copper sheet 32 is provided with a second slot, one end of the eighth solder layer 29 is connected to the outer wall of the second slot, and the other end of the eighth solder layer 29 is connected to the FRD chip 28. One end of the eighth solder layer 29 is connected to the outer wall of the second slot, and the other end is connected to the FRD chip. By optimizing the connection method of the solder layer through the slot, the stress is dispersed, the connection is stable, the electrical connection between the FRD chip and the second metal copper sheet 32 is reliable, and the current transmission is smooth. In complex working environments, even under the influence of factors such as temperature and vibration, stable connection can be maintained.

[0050] The above examples are only used to illustrate the technical solutions of the present disclosure, rather than limit them; although the present disclosure has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure. The following points need to be explained: only the structures involved in the embodiments of the present utility model are involved in the drawings of the embodiments of the present utility model, and other structures can refer to the usual design. In the case of no conflict, the features in the same embodiment and different embodiments of the present utility model can be combined with each other. The above is only a demonstrative implementation manner of the present utility model, rather than used to limit the protection scope of the present utility model, and the protection scope of the present utility model is determined by the appended claims.

Claims

1. A ceramic substrate-based IGBT module packaging structure, comprising a heat dissipation base plate (10), a shell (11) provided on the heat dissipation base plate (10), a first terminal (12) provided on one side of the shell (11), and a first solder layer (13), a first lower copper layer (14), a first ceramic substrate (15), a first upper copper layer (16), a second solder layer (17) and an IGBT chip (18) sequentially provided on the heat dissipation base plate (10) in the direction from the heat dissipation base plate (10) to the shell (11), characterized in that the ceramic substrate-based IGBT module packaging structure further comprises a first metal copper sheet (22), a third solder layer (19), a fourth solder layer (21) and a fifth solder layer (20), one end of the third solder layer (19) is connected to the IGBT chip (18), the other end of the third solder layer (19) is connected to the first metal copper sheet (22), one end of the fourth solder layer (21) is connected to the first terminal (12), the other end of the fourth solder layer (21) is connected to the first metal copper sheet (22), one end of the fifth solder layer (20) is connected to the first upper copper layer (16), and the other end of the fifth solder layer (20) is connected to the first metal copper sheet (22). A heat dissipation gap is left between the first metal copper sheet (22) and the first terminal (12), and a heat dissipation gap is left between the fifth solder layer (20) and the second solder layer (17), the IGBT chip (18), the third solder layer (19) and the fourth solder layer (21) respectively, and the heat dissipation gaps are filled with heat-conducting gel (33).

2. The ceramic substrate-based IGBT module package structure of claim 1, wherein, In the direction from the heat dissipation base plate (10) to the shell (11), the vertical distance from the upper wall of the first metal copper sheet (22) to the heat dissipation base plate (10) is L1, the vertical distance from the upper surface of the heat-conducting gel (33) to the heat dissipation base plate (10) is L2, and L1 < L2 is satisfied.

3. The ceramic substrate-based IGBT module package structure of claim 2, wherein, The first terminal (12) comprises a vertical section and a parallel section connected perpendicularly to each other, and the shell (11) is provided with a notch matching the shapes of the vertical section and the parallel section.

4. The ceramic substrate-based IGBT module package structure of claim 3, wherein, In the direction from the heat dissipation base plate (10) to the shell (11), the vertical distance from the upper end of the vertical section to the parallel section is L3, the vertical distance from the upper surface of the first metal copper sheet (22) to the parallel section is L4, and L3 > L4 is satisfied.

5. The ceramic substrate based IGBT module package structure of claim 4, wherein, The heat dissipation base plate (10) is further sequentially provided with a sixth solder layer (23), a second lower copper layer (24), a second ceramic substrate (25), a second upper copper layer (26), a seventh solder layer (27), an FRD chip, an eighth solder layer (29), a ninth solder layer (31), a tenth solder layer (30), a second metal copper sheet (32) and a second terminal (121).

6. The ceramic substrate-based IGBT module package structure of claim 5, wherein, ​ The sixth welding layer (23) is mirror-symmetrical to the first welding layer (13), the second lower copper layer (24) is mirror-symmetrical to the first lower copper layer (14), the second ceramic substrate (25) is mirror-symmetrical to the first ceramic substrate (15), the second upper copper layer (26) is mirror-symmetrical to the first upper copper layer (16), and the seventh welding layer (27) is mirror-symmetrical to the second welding layer (17). One end of the eighth welding layer (29) is connected to the FRD chip (28), and the other end of the eighth welding layer (29) is connected to the second metal copper sheet (32); one end of the ninth welding layer (31) is connected to the second terminal (121), and the other end of the ninth welding layer (31) is connected to the second metal copper sheet (32); one end of the tenth welding layer (30) is connected to the second upper copper layer (26), and the other end of the tenth welding layer (30) is connected to the second metal copper sheet (32).

7. The ceramic substrate based IGBT module package structure of claim 6, wherein, The second metal copper sheet (32) and the second terminal (121) are left with a heat dissipation gap, and the tenth welding layer (30) is left with a heat dissipation gap between the seventh welding layer (27), the FRD chip, the eighth welding layer (29) and the ninth welding layer (31) respectively; the IGBT chip (18) and the FRD chip (28) are left with a heat dissipation gap.

8. The ceramic substrate based IGBT module package structure of claim 7, wherein, The first metal copper sheet (22) and the second metal copper sheet (32) are left with a heat dissipation gap, the third welding layer (19) and the eighth welding layer (29) are left with a heat dissipation gap, the IGBT chip (18) and the FRD chip (28) are left with a heat dissipation gap, the second welding layer (17) and the seventh welding layer (27) are left with a heat dissipation gap, the first upper copper layer (16) and the second upper copper layer (26) are left with a heat dissipation gap, the first ceramic substrate (15) and the second ceramic substrate (25) are left with a heat dissipation gap, the first lower copper layer (14) and the second lower copper layer (24) are left with a heat dissipation gap, and the first welding layer (13) and the sixth welding layer (23) are left with a heat dissipation gap.

9. The ceramic substrate based IGBT module package structure of claim 8, wherein, The first metal copper sheet (22) is provided with a first notch, one end of the third welding layer (19) is connected to the outer wall of the notch, and the other end of the third welding layer (19) is connected to the IGBT chip (18).

10. A ceramic substrate based IGBT module package structure according to any one of claims 6-9, characterized in that, The second metal copper sheet (32) is provided with a second notch, one end of the eighth welding layer (29) is connected to the outer wall of the second notch, and the other end of the eighth welding layer (29) is connected to the FRD chip (28).

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