Power module with reinforced binding point strength

Abstract

The utility model discloses a power module with reinforced binding point strength, comprising a housing, the bottom of the housing is provided with a bottom plate, the edge of the housing is fixedly provided with a plurality of electrodes, the bottom plate is fixedly provided with a printed circuit board, a binding point area is formed between the electrodes and the printed circuit board, and the binding point area is internally provided with a plurality of bonding wires. The plurality of bonding wires are electrically connected between the plurality of electrodes and the printed circuit board, the binding point area is filled with a hard protective layer, the plurality of bonding wires are all arranged in the hard protective layer, the shell is filled with a pouring sealant, and the hard protective layer is arranged in the pouring sealant. Compared with the prior art, the hard protective layer with certain hardness is used for protecting the plurality of bonding wires, so that the vibration resistance of the plurality of bonding wires is better, and then the casing outside the plurality of bonding wires is filled with the pouring sealant, so that under the combined action of the hard protective layer and the pouring sealant, not only can the bonding wires be effectively protected, but also the service life of the bonding wires is prolonged. And the connection reliability of the bonding wire can be improved, so that the overall performance of the power module is improved.

Description

Technical Field

[0001] The utility model relates to a power module, in particular to a power module with reinforced bonding point strength. Background Art

[0002] In the design and development process of power modules, the bonding process is an essential part. This process involves using bonding wires (aluminum wires or copper wires) and connecting various devices tightly together through ultrasonic bonding to meet the requirements of circuit topology construction. The bonding wire is one of the softest parts inside the module and is also the key point most likely to fail under vibration tests.

[0003] Existing potted power modules internally use potted silicone gel for protection. This material can not only play an insulating role but also effectively prevent dust. However, after curing, the silicone gel presents a transparent elastomer state and does not have hardness itself. Therefore, in a strong vibration environment, it cannot provide effective fixation for the bonding wires inside the power module and thus cannot play a vibration protection role. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a power module with reinforced bonding point strength, which has better anti-vibration performance, can effectively protect bonding wires, and can improve the connection reliability of bonding wires, aiming at the deficiencies of the prior art.

[0005] To solve the above technical problem, the utility model adopts the following technical solutions.

[0006] A power module with reinforced bonding point strength includes a housing. A bottom plate is provided at the bottom of the housing. A plurality of electrodes are fixed on the edge of the housing. A printed circuit board is fixed on the bottom plate. A bonding point area is formed between the electrodes and the printed circuit board. A plurality of bonding wires are provided in the bonding point area. The plurality of bonding wires are electrically connected between the plurality of electrodes and the printed circuit board. A hard protective layer is filled in the bonding point area. The plurality of bonding wires are all arranged in the hard protective layer. Potting glue is filled in the housing. The hard protective layer is arranged in the potting glue.

[0007] Preferably, the hard protective layer is a transparent protective layer.

[0008] Preferably, the hard protective layer is a UV glue layer or an epoxy resin layer cured by ultraviolet light.

[0009] Preferably, the bonding wire is an aluminum wire or a copper wire.

[0010] Preferably, the potting glue is silicone gel.

[0011] The power module with reinforced bonding point strength disclosed by the present utility model, during the processing, first prepare the semi-finished power module, the raw material of the hard protective layer, and the raw material of the potting adhesive. Multiple bonding wires in the semi-finished power module are electrically connected between multiple electrodes and the printed circuit board, so that multiple bonding wires are welded in the bonding point area. Then, load the raw material of the hard protective layer into a three-axis dispensing machine, and use the three-axis dispensing machine to perform dispensing treatment on the bonding point area between the electrodes and the printed circuit board, thereby forming the hard protective layer. After the hard protective layer is cured, use the potting machine to perform potting treatment on the inside of the housing, so that the potting adhesive fills the housing and completely covers the hard protective layer. Compared with the prior art, the present utility model uses the hard protective layer with a certain hardness to protect multiple bonding wires, making the anti-vibration performance of the multiple bonding wires better. Then, fill the potting adhesive in the housing outside it. Under the combined action of the hard protective layer and the potting adhesive, it can not only effectively protect the bonding wires, but also improve the connection reliability of the bonding wires, thereby enhancing the overall performance of the power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. is a perspective view of the power module of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] The present utility model will be described in more detail below with reference to the drawings and embodiments.

[0014] The present utility model discloses a power module with reinforced bonding point strength. Please refer to Figure 1 , which includes a housing 1. A bottom plate 2 is provided at the bottom of the housing 1. A plurality of electrodes 3 are fixed on the edge of the housing 1. A printed circuit board 4 is fixed on the bottom plate 2. A bonding point area is formed between the electrodes 3 and the printed circuit board 4. Multiple bonding wires 5 are provided in the bonding point area. The multiple bonding wires 5 are electrically connected between the multiple electrodes 3 and the printed circuit board 4. A hard protective layer 6 is filled in the bonding point area. The multiple bonding wires 5 are all arranged in the hard protective layer 6. The housing 1 is filled with a potting adhesive 7. The hard protective layer 6 is arranged in the potting adhesive 7.

[0015] During the processing of the above power module, first prepare the semi-finished power module, the raw material of the hard protective layer, and the raw material of the potting glue. Multiple bonding wires 5 in the semi-finished power module are electrically connected between multiple electrodes 3 and the printed circuit board 4, so that multiple bonding wires 5 are formed by welding in the bonding point area. Then, load the raw material of the hard protective layer into a three-axis dispensing machine, and use the three-axis dispensing machine to perform dispensing treatment on the bonding point area between the electrode 3 and the printed circuit board 4, thereby forming the hard protective layer 6. After the hard protective layer 6 is cured, use the potting machine to perform potting treatment on the inside of the housing 1, so that the potting glue 7 fills the housing 1 and completely covers the hard protective layer 6. Compared with the prior art, the utility model uses the hard protective layer 6 with a certain hardness to protect the multiple bonding wires 5, so that the anti-vibration performance of the multiple bonding wires 5 is better. Then, fill the potting glue 7 in the housing 1 outside it. Under the combined action of the hard protective layer 6 and the potting glue 7, not only can the bonding wires be effectively protected, but also the connection reliability of the bonding wires can be improved, thereby improving the overall performance of the power module.

[0016] As a preferred method, the hard protective layer 6 is a transparent protective layer. It can be cured by UV glue. Specifically, in this embodiment, the hard protective layer 6 is a UV glue layer or an epoxy resin layer cured by ultraviolet rays.

[0017] In this embodiment, the bonding wire 5 is an aluminum wire or a copper wire.

[0018] In order to play a role in soft glue potting protection, in this embodiment, the potting glue 7 is a silicone gel.

[0019] On this basis, this embodiment also proposes a method for strengthening the bonding point strength of a power module. Please refer to Figure 1 , which includes:

[0020] Step S1, prepare the semi-finished power module, the raw material of the hard protective layer, and the raw material of the potting glue. The power module includes a housing 1. A bottom plate 2 is provided at the bottom of the housing 1. A plurality of electrodes 3 are fixed on the edge of the housing 1. A printed circuit board 4 is fixed on the bottom plate 2. A bonding point area is formed between the electrode 3 and the printed circuit board 4. Multiple bonding wires 5 are arranged in the bonding point area. Multiple bonding wires 5 are electrically connected between multiple electrodes 3 and the printed circuit board 4;

[0021] Step S2, load the raw material of the hard protective layer into a three-axis dispensing machine, and use the three-axis dispensing machine to perform dispensing treatment on the bonding point area between the electrode 3 and the printed circuit board 4, so that a hard protective layer 6 is formed in the bonding point area, and the hard protective layer 6 completely covers multiple bonding wires 5;

[0022] Step S3, cure the hard protective layer 6;

[0023] Step S4: Load the potting glue raw material into the potting machine, and use the potting machine to perform potting treatment on the inside of the housing 1, so that the potting glue 7 completely covers the hard protective layer 6.

[0024] As a preferred method, in the step S2, the hard protective layer raw material is UV glue. Further, in the step S2, when using a three-axis dispensing machine to perform dispensing treatment on the bonding point area, the dispensing air pressure is set to 0.3 MPa. After dispensing, it is required that the UV glue covers the bonding wire 5 and its bonding points.

[0025] Regarding the preferred curing method, in the step S3 of this embodiment, use a UV ultraviolet lamp to irradiate the UV glue until the UV glue cures. Among them, the irradiation distance of the UV ultraviolet lamp is 10 cm to 40 cm, and the irradiation time is 20 s.

[0026] The method for strengthening the bonding point strength of the power module disclosed by the present utility model can refer to the following preferred processing steps in its actual application:

[0027] Step 1: Prepare a one-component ultraviolet curable adhesive (referred to as UV glue), a semi-finished module that has completed the bonding between the outer shell terminals and the DBC (hereinafter referred to as the semi-finished module), and AB silicone gel;

[0028] Step 2: Take out the UV glue that is protected from light and refrigerated in the refrigerator, and use a three-axis dispensing machine to dispense the bonding point part of the outer shell terminals of the semi-finished module with UV glue. The dispensing air pressure is 0.3 MPa. When dispensing, it is necessary to maintain a constant speed and a fixed amount. At the end of dispensing, it is necessary to ensure that the UV glue can completely cover all the bonding points and the highest point of the bonding wire arc height on the terminal table (the dispensing air pressure and the glue application speed can be set by yourself according to different equipment, and it is necessary to ensure that it can be evenly and comprehensively covered);

[0029] Step 3: Use a UV ultraviolet lamp to irradiate the UV glue. The irradiation distance is guaranteed to be between 10 cm and 40 cm, and the irradiation time is 20 s to cure the UV glue (the UV ultraviolet lamp used this time has a specification of 395 nm 500 W. If other specifications of UV ultraviolet lamps are used, the irradiation time can be appropriately changed to ensure the curing of the glue);

[0030] Step 4: Use a potting machine, a dust blower, a degassing machine and an oven to perform normal module potting and encapsulation treatment on the semi-finished module, and pot it into a finished module;

[0031] Based on the above process method, in this embodiment, a special protective layer is added to the bonding wire to achieve the hard protection function. This protective layer not only has the functions of insulation and dust prevention, but also has a certain hardness after curing, and can effectively provide a firm fixation for the bonding wire in the power module.

[0032] In practical applications, the hard protective layer can be made of materials such as UV glue, silica gel, epoxy resin, etc., which have insulation, dust-proof properties and a certain hardness after curing.

[0033] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the technical scope of the present invention shall be included within the scope protected by the present invention.

Claims

1. A power module with reinforced binding point strength, characterized in that, It includes a housing (1), a bottom plate (2) is provided at the bottom of the housing (1), a plurality of electrodes (3) are fixed to the edge of the housing (1), a printed circuit board (4) is fixed on the bottom plate (2), a bonding point area is formed between the electrode (3) and the printed circuit board (4), a plurality of bonding wires (5) are provided in the bonding point area, the plurality of bonding wires (5) are electrically connected between the plurality of electrodes (3) and the printed circuit board (4), a hard protective layer (6) is filled in the bonding point area, the plurality of bonding wires (5) are all arranged in the hard protective layer (6), potting glue (7) is filled in the housing (1), and the hard protective layer (6) is arranged in the potting glue (7).

2. The power module with reinforced binding point strength as described in claim 1, wherein The hard protective layer (6) is a transparent protective layer.

3. The power module with reinforced binding point strength as described in claim 1, wherein, The hard protective layer (6) is a UV glue layer or an epoxy resin layer cured by ultraviolet rays.

4. The power module with strengthened binding point strength as described in claim 1, characterized in that, The bonding wire (5) is an aluminum wire or a copper wire.

5. The power module with reinforced binding point strength as described in claim 1, wherein The potting glue (7) is silicone gel.

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