Insulated gate bipolar transistor (IGBT) packaging structure based on copper-clad ceramic substrate

Abstract

The utility model discloses an IGBT packaging structure based on copper-clad ceramic substrates. The IGBT packaging structure comprises a heat radiation pedestal, a first copper-clad ceramic substrate, a second copper-clad ceramic substrate, a semiconductor chip, a power electrode, a control electrode, a gel layer and an epoxy resin layer. The heat dissipation base is provided with an accommodating cavity with an upward opening; the first copper-clad ceramic substrate and the second copper-clad ceramic substrate are welded and fixed on the bottom surface of the accommodating cavity; the semiconductor chip is welded on the first copper-clad ceramic substrate and is connected with a circuit on the first copper-clad ceramic substrate in a conducting mode. The first copper-clad ceramic substrate, the second copper-clad ceramic substrate and the semiconductor chip are well sealed in the containing cavity through the cooperation of the gel layer and the epoxy resin layer, the sealing effect is better, the waterproof requirement is completely met, meanwhile, heat dissipation can be well conducted through the heat dissipation base, the heat dissipation effect is better, and the application range of the product is wider.

Description

Technical Field

[0001] The utility model relates to the technical field of ceramic substrate packaging structures, in particular to an IGBT packaging structure based on a copper-clad ceramic substrate. Background Technique

[0002] The insulated gate bipolar transistor IGBT (Insulated Gate Bipolar Transistor) has the advantages of high switching frequency of unipolar devices and low conduction voltage drop of bipolar devices, and plays an irreplaceable role in high-power application fields such as industrial control, wind power generation, rail transit, and power systems.

[0003] When producing IGBTs, a packaging structure is usually required. The current IGBT packaging structure includes a bottom plate, a copper-clad ceramic substrate, a semiconductor chip, a power electrode, a control electrode, and an insulating packaging structure; the bottom plate and the insulating packaging structure are distributed from bottom to top in sequence. The upper and lower surfaces of the copper-clad ceramic substrate are respectively welded to the semiconductor chip and the bottom plate. The copper-clad ceramic substrate and the semiconductor chip are both packaged inside the insulating packaging structure, and the power electrode passes through the insulating packaging structure and is connected to the copper-clad ceramic substrate.

[0004] However, in the prior art, the bottom plate is a flat structure, and the copper-clad ceramic substrate and the insulating packaging structure are directly arranged on the surface of the bottom plate, resulting in poor sealing effect, unable to meet the good waterproof requirement, and the heat dissipation effect is also not ideal, leading to a small application range of the product. Therefore, it is necessary to improve the current IGBT packaging structure. Content of the Utility Model

[0005] In view of this, aiming at the deficiencies existing in the prior art, the main purpose of the present utility model is to provide an IGBT packaging structure based on a copper-clad ceramic substrate, which can effectively solve the problems of poor sealing effect and unsatisfactory heat dissipation effect of the existing IGBT packaging structure.

[0006] To achieve the above purpose, the present utility model adopts the following technical solutions:

[0007] An IGBT packaging structure based on a copper-clad ceramic substrate, comprising a heat dissipation base, a first copper-clad ceramic substrate, a second copper-clad ceramic substrate, a semiconductor chip, a power electrode, a control electrode, a gel layer and an epoxy resin layer; the heat dissipation base has a receiving cavity with an upward opening; the first copper-clad ceramic substrate and the second copper-clad ceramic substrate are both welded and fixed on the bottom surface of the receiving cavity; the semiconductor chip is welded on the first copper-clad ceramic substrate and is electrically connected to the circuit on the first copper-clad ceramic substrate, and the semiconductor chip is electrically connected to the circuit on the second copper-clad ceramic substrate through a bonding aluminum wire; the power electrode is welded on the first copper-clad ceramic substrate and is electrically connected to the circuit on the first copper-clad ceramic substrate, and the power electrode extends upward out of the receiving cavity; the control electrode is welded on the second copper-clad ceramic substrate and is electrically connected to the circuit on the second copper-clad ceramic substrate, and the control electrode extends upward out of the receiving cavity; the gel layer is filled and formed in the receiving cavity, and the gel layer seals and covers the first copper-clad ceramic substrate, the second copper-clad ceramic substrate and the semiconductor chip; the epoxy resin layer is filled and formed in the receiving cavity and is laminated on the gel layer, and the power electrode and the control electrode both pass through the gel layer and the epoxy resin layer and extend upward out of the receiving cavity.

[0008] As a preferred solution, the heat dissipation base is made of aluminum alloy and is formed by die casting.

[0009] As a preferred solution, the power electrode includes a first lower segment and a first upper segment, the first upper segment and the first lower segment are arranged up and down and integrally connected, the first lower segment is in a wavy bent shape, the first lower segment is buried in the gel layer and the epoxy resin layer, the first upper segment is exposed above the epoxy resin layer, and a first nickel plating layer is formed by electroplating on the outer surface of the first upper segment, so that the power electrode is more firmly combined with the gel layer and the epoxy resin layer, and the waterproof and sealing effect is also better.

[0010] As a preferred solution, both the first lower segment and the first upper segment are made of copper, and have good electrical conductivity.

[0011] As a preferred solution, the control electrode includes a second lower segment and a second upper segment, the second upper segment and the second lower segment are arranged up and down and integrally connected, the second lower segment is in a wavy bent shape, the second lower segment is buried in the gel layer and the epoxy resin layer, the second upper segment is exposed above the epoxy resin layer, and a second nickel plating layer is formed by electroplating on the outer surface of the second upper segment, so that the control electrode is more firmly combined with the gel layer and the epoxy resin layer, and the waterproof and sealing effect is also better.

[0012] As a preferred solution, both the second lower segment and the second upper segment are made of copper, and have good electrical conductivity.

[0013] Compared with the prior art, the present utility model has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solutions:

[0014] By adopting a heat dissipation base, which has a receiving cavity, and cooperating with a gel layer and an epoxy resin layer to well seal the first copper-clad ceramic substrate, the second copper-clad ceramic substrate and the semiconductor chip in the receiving cavity, the sealing effect is better, fully meeting the waterproof requirements. At the same time, the heat dissipation base can dissipate heat well, with better heat dissipation effect, and the application range of the product is wider.

[0015] To more clearly elaborate on the structural features and functions of the present utility model, the following will detail the present utility model in conjunction with the accompanying drawings and specific embodiments. Brief Description of the Drawings

[0016] Figure 1 It is a cross-sectional schematic diagram of a preferred embodiment of the present utility model.

[0017] Description of the Reference Numerals in the Drawings:

[0018] 10. Heat dissipation base 11. Base

[0019] 12. Boss 101. Receiving cavity

[0020] 20. First copper-clad ceramic substrate 30. Second copper-clad ceramic substrate

[0021] 40. Semiconductor chip 41. Bonding aluminum wire

[0022] 50. Power electrode 51. First lower segment

[0023] 52. First upper segment 53. First nickel plating layer

[0024] 60. Control electrode 61. Second lower segment

[0025] 62. Second upper segment 63. Second nickel plating layer

[0026] 70. Gel layer 80. Epoxy resin layer. Detailed Description of the Embodiment

[0027] Please refer to Figure 1 As shown, it shows the specific structure of a preferred embodiment of the present utility model, including a heat dissipation base 10, a first copper-clad ceramic substrate 20, a second copper-clad ceramic substrate 30, a semiconductor chip 40, a power electrode 50, a control electrode 60, a gel layer 70, and an epoxy resin layer 80.

[0028] The heat dissipation base 10 has a receiving cavity 101 with an upward opening. In this embodiment, the heat dissipation base 10 is made of aluminum alloy, which is formed by die-casting. It has a simple structure, is easy to manufacture, has a light weight, good strength, and excellent heat dissipation effect. Specifically, the heat dissipation base 10 includes a base 11 and a boss 12 integrally protruding upward from the base 11. The outer contour of the base 11 is square, and the outer contour of the boss 12 is cylindrical. The receiving cavity 101 is recessed on the surface of the boss 12.

[0029] Both the first copper-clad ceramic substrate 20 and the second copper-clad ceramic substrate 30 are welded and fixed on the bottom surface of the receiving cavity 101. The specific structures of the first copper-clad ceramic substrate 20 and the second copper-clad ceramic substrate 30 are prior arts, and the specific structures of the first copper-clad ceramic substrate 20 and the second copper-clad ceramic substrate 30 will not be described in detail here.

[0030] The semiconductor chip 40 is welded on the first copper-clad ceramic substrate 20 and conductively connected to the circuit on the first copper-clad ceramic substrate 20. Moreover, the semiconductor chip 40 is conductively connected to the circuit on the second copper-clad ceramic substrate 30 through a bonding aluminum wire 41. The semiconductor chip 40 includes an IGBT chip and a fast recovery diode FRD chip.

[0031] The power electrode 50 is welded on the first copper-clad ceramic substrate 20 and conductively connected to the circuit on the first copper-clad ceramic substrate 20. The power electrode 50 extends upward out of the receiving cavity 101. Specifically, the power electrode 50 includes a first lower section 51 and a first upper section 52. The first upper section 52 and the first lower section 51 are arranged vertically and integrally connected. The first lower section 51 is in a wavy bent shape. A first nickel plating layer 53 is formed by electroplating on the outer surface of the first upper section 52 to prevent the functional electrode 50 from being easily oxidized. Also, both the first lower section 51 and the first upper section 52 are made of copper, and have good electrical conductivity.

[0032] The control electrode 60 is welded on the second copper-clad ceramic substrate 30 and conductively connected to the circuit on the second copper-clad ceramic substrate 30. The control electrode 60 extends upward out of the receiving cavity 101. Specifically, the control electrode 60 includes a second lower section 61 and a second upper section 62. The second upper section 62 and the second lower section 61 are arranged vertically and integrally connected. The second lower section 61 is in a wavy bent shape. A second nickel plating layer 63 is formed by electroplating on the outer surface of the second upper section 62 to prevent the power electrode 50 from being easily oxidized. Also, both the second lower section 61 and the second upper section 62 are made of copper, and have good electrical conductivity.

[0033] The gel layer 70 is filled and formed in the accommodation cavity 101, and the gel layer 70 hermetically covers the first copper-clad ceramic substrate 20, the second copper-clad ceramic substrate 30, and the semiconductor chip 40. The epoxy resin layer 80 is filled and formed in the accommodation cavity 101 and laminated on the gel layer 70. Both the power electrode 50 and the control electrode 60 pass through the gel layer 70 and the epoxy resin layer 80 and protrude upward out of the accommodation cavity. In this embodiment, the first lower section 51 is buried in the gel layer 70 and the epoxy resin layer 80, and the first upper section 52 is exposed above the epoxy resin layer 80, so that the power electrode 50 is more firmly combined with the gel layer 70 and the epoxy resin layer 80, and the waterproof and sealing effect is also better; and, the second lower section 61 is buried in the gel layer 70 and the epoxy resin layer 80, and the second upper section 62 is exposed above the epoxy resin layer 80, so that the control electrode 60 is more firmly combined with the gel layer 70 and the epoxy resin layer 80, and the waterproof and sealing effect is also better.

[0034] The manufacturing process of this embodiment is described in detail as follows:

[0035] During manufacturing, first, the semiconductor chip 40 is soldered to the first copper-clad ceramic substrate 20 for conduction connection, and the power electrode 50 and the control electrode 60 are respectively soldered to the first copper-clad ceramic substrate 20 and the second copper-clad ceramic substrate 30 for conduction connection. Then, the first copper-clad ceramic substrate 20 and the second copper-clad ceramic substrate 30 are soldered to the bottom surface of the accommodation cavity 101 for fixation. Then, both ends of the bonding aluminum wire 41 are soldered and conducted with the semiconductor chip 40 and the second copper-clad ceramic substrate 30 respectively. Then, gel is filled into the accommodation cavity 101 to form the gel layer 70. Finally, epoxy resin is filled into the accommodation cavity 101 to form the epoxy resin layer 80. When in use, the power electrode 50 and the control electrode 60 are connected to an external circuit.

[0036] The design focus of the present utility model lies in: by adopting a heat dissipation base with an accommodation cavity, and cooperating with the gel layer and the epoxy resin layer to well seal the first copper-clad ceramic substrate, the second copper-clad ceramic substrate, and the semiconductor chip in the accommodation cavity, the sealing effect is better, fully meeting the waterproof requirements. At the same time, the heat dissipation base can dissipate heat well, with a better heat dissipation effect, and the application range of the product is wider.

[0037] The above description is only a preferred embodiment of the present utility model, and does not impose any limitation on the technical scope of the present utility model. Therefore, any minor modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present utility model still fall within the scope of the technical solution of the present utility model.

Claims

1. An IGBT packaging structure based on a copper-clad ceramic substrate, characterized in that: The invention comprises a heat dissipation base, a first copper-clad ceramic substrate, a second copper-clad ceramic substrate, a semiconductor chip, a power electrode, a control electrode, a gel layer and an epoxy resin layer; the heat dissipation base has a receiving cavity with an opening facing upward; the first copper-clad ceramic substrate and the second copper-clad ceramic substrate are both welded and fixed on the bottom surface of the receiving cavity; the semiconductor chip is welded on the first copper-clad ceramic substrate and is connected to the circuit on the first copper-clad ceramic substrate, and the semiconductor chip is connected to the circuit on the second copper-clad ceramic substrate through a bonding aluminum wire; the power electrode is welded on the first copper-clad ceramic substrate and is connected to the circuit on the first copper-clad ceramic substrate, and the power electrode extends upward from the receiving cavity; the control electrode is welded on the second copper-clad ceramic substrate and is connected to the circuit on the second copper-clad ceramic substrate, and the control electrode extends upward from the receiving cavity; the gel layer is filled and formed in the receiving cavity, and the gel layer seals and covers the first copper-clad ceramic substrate, the second copper-clad ceramic substrate and the semiconductor chip; the epoxy resin layer is filled and formed in the receiving cavity and overlapped on the gel layer, and the power electrode and the control electrode both pass through the gel layer and the epoxy resin layer and extend upward from the receiving cavity.

2. The IGBT packaging structure based on a copper-clad ceramic substrate according to claim 1, characterized in that: The heat dissipation base is made of aluminum alloy and is formed by die-casting.

3. The IGBT packaging structure based on a copper-clad ceramic substrate according to claim 1, characterized in that: The power electrode includes a first lower section and a first upper section, which are arranged up and down and connected as a whole, the first lower section is wavy and bent, the first lower section is buried in the gel layer and the epoxy resin layer, the first upper section is exposed above the epoxy resin layer, and the outer surface of the first upper section is electroplated and covered with a first nickel plating layer.

4. The IGBT packaging structure based on a copper-clad ceramic substrate according to claim 3, characterized in that: The first lower section and the first upper section are both made of copper.

5. The IGBT packaging structure based on a copper-clad ceramic substrate according to claim 1, characterized in that: The control electrode includes a second lower section and a second upper section, which are arranged up and down and connected as a whole, the second lower section is wavy and bent, the second lower section is buried in the gel layer and the epoxy resin layer, the second upper section is exposed above the epoxy resin layer, and the outer surface of the second upper section is electroplated and covered with a second nickel plating layer.

6. The IGBT packaging structure based on a copper-clad ceramic substrate according to claim 5, characterized in that: The second lower section and the second upper section are both made of copper.

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