Power module electrode needle internal connection structure and power module

Abstract

The present invention provides an internal connection structure of an electrode needle of a power module and a power module, belonging to the technical field of power modules, comprising: a shell pre-molded with an electrode needle; an insulating substrate arranged inside the shell, the insulating substrate having a conductive copper tape; the insulating substrate is connected to the bottom of the electrode needle through the conductive copper tape by a copper-copper bonding process. Beneficial effects: The insulating substrate of the present invention uses a conductive copper tape as a connecting medium to perform copper-copper bonding with the electrode needle. Compared with the connection method of aluminum wire bonding, the connection area of ​​the conductive copper tape is increased, the ultrasonic power is high, and the bonding process requirements are reduced; and because the insulating substrate and the electrode needle are not directly subjected to the copper-copper bonding process, the risk of damaging the ceramic during the bonding process, thereby reducing its insulation capacity, is avoided; at the same time, the heat generated at the bonding point can be dissipated from the insulating substrate, reducing the material requirements for the plastic shell and the electrode needle, and can significantly reduce costs.

Description

Technical Field

[0001] The present invention relates to the technical field of power modules, and in particular to an internal connection structure of electrode pins of a power module and a power module. Background Art

[0002] Power modules are widely used in the power industry, such as inverters, photovoltaics, power compensation, electric vehicles, hybrid vehicles and other fields. In the existing internal circuit connection structure, the electrodes of the power module are usually embedded and integrally injection-molded in the plastic shell, and then the direct bonding copper (DBC) is directly connected to the electrode pins through the aluminum wire bonding process. Figure 1-Figure 4 The aluminum wire bonding process uses ultrasonic energy to connect the aluminum wire and the aluminum surface of the electrode needle through atomic bonding.

[0003] This bonding method has very high requirements for the material of the electrode needle bonding surface. Since the main body of the electrode needle is copper material and the bonding surface is aluminum material, a complex copper-aluminum composite process needs to be adopted. At the same time, the manufacturing process of the plastic shell frame is very demanding. Once the injection molding surface of the electrode needle and the plastic shell becomes loose, it will cause the loss of ultrasonic energy, thereby rendering the process ineffective. When the existing power module is working, the bonding point of the electrode needle will heat up, and the plastic material has a large thermal resistance and poor heat dissipation, thereby generating high and low temperature stress, causing the electrode needle to fall off, affecting the service life of the power module. Therefore, in response to the above problems, the present invention proposes a new type of power module electrode needle internal connection structure and power module. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an internal connection structure of electrode needles of a power module and a power module.

[0005] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0006] A power module electrode pin internal connection structure, comprising:

[0007] A housing, wherein electrode needles are pre-injected on the housing;

[0008] an insulating substrate, disposed inside the housing, the insulating substrate having a conductive copper strip;

[0009] The insulating substrate is connected to the bottom of the electrode needle through the conductive copper tape by a copper-copper bonding process.

[0010] Preferably, the insulating substrate further comprises a front copper foil layer;

[0011] The conductive copper tape is obtained by three-dimensional processing of the edge of the front copper foil layer.

[0012] Preferably, the insulating substrate further comprises: a back copper foil layer, and a ceramic layer located between the front copper foil layer and the back copper foil layer.

[0013] Preferably, the ceramic layer is made of alumina ceramics.

[0014] Preferably, the conductive copper strip is made of red copper.

[0015] Preferably, the electrode needle is made of pure copper.

[0016] Preferably, the insulating substrate is a direct-clad copper substrate.

[0017] Preferably, the housing is made of plastic.

[0018] Preferably, the insulating substrate includes a plurality of insulating substrates, and different insulating substrates are connected by an aluminum wire bonding process.

[0019] The present invention also provides a power module, comprising the power module electrode needle internal connection structure as described above.

[0020] The advantages or beneficial effects of the technical solution of the present invention are:

[0021] The insulating substrate of the present invention uses a conductive copper tape as a connecting medium to perform copper-copper bonding with the electrode needle. Compared with the connection method of aluminum wire bonding, the connection area of ​​the conductive copper tape is increased, the ultrasonic power is high, and the bonding process requirements are reduced. Moreover, since the copper-copper bonding process is not directly performed on the insulating substrate and the electrode needle, the risk of damaging the ceramic during the bonding process, thereby reducing its insulation ability, is avoided. At the same time, the heat generated at the bonding point can be dissipated from the insulating substrate, reducing the material requirements for the plastic shell and the electrode needle, and significantly reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the appearance and structure of a power module in the prior art;

[0023] Figure 2 This is a schematic diagram of the internal connection structure of a power module in the prior art;

[0024] Figure 3 A top view of the internal connection structure of a power module in the prior art;

[0025] Figure 4 This is a left side view of the internal connection structure of a power module in the prior art;

[0026] Figure 5 This is a schematic structural diagram of the internal connection structure of the power module electrode needle in a preferred embodiment of the present invention;

[0027] Figure 6 A top view of the internal connection structure of the power module electrode pins in a preferred embodiment of the present invention;

[0028] Figure 7 This is a left side view of the internal connection structure of the power module electrode needle in a preferred embodiment of the present invention.

[0029] Reference numerals:

[0030] 1. Housing; 2. Electrode needle; 3. Insulating substrate; 4. Conductive copper tape; 5. Aluminum bonding wire. DETAILED DESCRIPTION

[0031] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments may also fall within the scope of the present invention as long as they conform to the gist of the present invention.

[0032] In a preferred embodiment of the present invention, based on the above problems existing in the prior art, a power module electrode needle 2 internal connection structure is provided, which belongs to the field of power module technology. Figure 5-Figure 6 As shown, including:

[0033] A housing 1, wherein an electrode needle 2 is pre-injected on the housing 1;

[0034] An insulating substrate 3 is disposed inside the housing 1 and has a conductive copper tape 4;

[0035] The insulating substrate 3 is connected to the bottom of the electrode needle 2 through the conductive copper tape 4 by a copper-copper bonding process.

[0036] Specifically, in this embodiment, several electrode needles 2 are embedded and distributed within a housing 1, typically a plastic housing 1, and are connected to the housing 1 via integral injection molding. An insulating substrate 3 is disposed within the housing 1, preferably a direct bonding copper (DBC) substrate. The insulating substrate 3 utilizes a conductive copper tape 4 as a connecting medium for copper-to-copper bonding with the bottoms of the electrode needles 2. Compared to aluminum wire bonding, the conductive copper tape 4 provides a larger connection area, higher ultrasonic power, and lower surface cleanliness requirements for the electrode needles 2, thereby reducing bonding process requirements.

[0037] In response to the prior art of directly performing a copper-copper bonding process on the insulating substrate 3 and the electrode needle 2, the present invention innovatively proposes using a conductive copper tape 4 as a connecting medium, thereby avoiding the risk of damaging the ceramic layer of the insulating substrate 3 during the direct bonding process, thereby reducing its insulation capacity.

[0038] Furthermore, since the thermal resistance of the ceramic layer is much lower than that of plastic, the heat generated at the bonding point can be dissipated from the ceramic layer of the insulating substrate 3, avoiding high and low temperature stress at the bonding point that causes the electrode needle 2 to fall off, reducing the material requirements for the plastic shell 1 and the electrode needle 2, which can greatly reduce costs and extend the service life of the power module.

[0039] As a preferred embodiment, the insulating substrate 3 further includes a front copper foil layer;

[0040] The conductive copper tape 4 is obtained by three-dimensional processing of the edge of the front copper foil layer.

[0041] Specifically, the conventional front copper foil layer of the insulating substrate 3 is planar. This embodiment of the present invention renders the conventional planar front copper foil layer three-dimensional, allowing the copper foil at the edge of the insulating substrate 3 to be extended to form a conductive copper strip 4. The extended conductive copper strip 4 serves as a connecting medium, achieving a copper-copper bonding connection between the insulating substrate 3 and the electrode pins 2.

[0042] As a preferred embodiment, the conductive copper strip 4 is made of red copper.

[0043] Specifically, in this embodiment, the conductive copper strip 4 is made of red copper. Red copper is relatively soft, has good electrical conductivity and plasticity, and exhibits excellent thermal conductivity, ductility, weldability, and corrosion resistance. Replacing the existing aluminum bonding wire 5 with the conductive copper strip 4 increases the contact area at the connection. When heat is generated at the bonding point, it is transferred through the conductive copper strip 4 to the insulating substrate 3 and then dissipated through the ceramic layer. This prevents excessive heat at the bonding point from causing the electrode pin 2 to fall off, thus resolving the heat dissipation issue at the bonding point.

[0044] As a preferred embodiment, the insulating substrate 3 further includes: a back copper foil layer, and a ceramic layer located between the front copper foil layer and the back copper foil layer.

[0045] As a preferred embodiment, the ceramic layer is made of alumina (Al2O3) ceramics.

[0046] Specifically, in this embodiment, the insulating substrate 3 is a three-dimensional structure with a conductive copper tape 4, which specifically includes a front copper foil layer, and the edge copper foil of the front copper foil layer can be extended to form a conductive passband, an Al2O3 ceramic layer in the middle, and a back copper foil layer, replacing the existing planar DBC board.

[0047] As a preferred embodiment, the electrode needle 2 is made of pure copper.

[0048] Specifically, in this embodiment, pure copper electrode needles 2 are used instead of the existing copper-aluminum composite electrode needles 2. The pure copper electrode needles 2 are electrically connected to the DBC board with extended copper foil through a copper-copper bonding process. The DBC board's inherent conductive copper tape 4 serves as the connecting medium, and ultrasonic energy is used to bond the copper atoms of the conductive copper tape 4 to the copper atoms of the electrode needles 2.

[0049] As a preferred embodiment, the housing 1 is made of plastic.

[0050] As a preferred embodiment, the insulating substrate 3 includes multiple insulating substrates, and different insulating substrates 3 are connected by an aluminum wire bonding process.

[0051] Specifically, in this embodiment, multiple insulating substrates 3 are disposed within the plastic housing 1 of the power module. These insulating substrates 3 are DBC boards, which can be of the same or different sizes and shapes. The front copper foil layers of different insulating substrates 3 are connected via an aluminum wire bonding process.

[0052] The present invention further provides a power module, comprising the above-mentioned internal connection structure of the power module electrode needle 2 .

[0053] The above technical solution has the following advantages or beneficial effects: the insulating substrate of the present invention uses a conductive copper tape as a connecting medium to perform copper-copper bonding with the electrode needle. Compared with the connection method of aluminum wire bonding, the connection area of ​​the conductive copper tape is increased, the ultrasonic power is high, and the bonding process requirements are reduced; and since the copper-copper bonding process is not directly performed on the insulating substrate and the electrode needle, the risk of damaging the ceramic during the bonding process, thereby reducing its insulation ability, is avoided; at the same time, the heat generated at the bonding point can be dissipated from the insulating substrate, reducing the material requirements for the plastic shell and the electrode needle, and can greatly reduce costs.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A power module electrode pin internal connection structure, characterized in that: include: A housing, wherein electrode needles are pre-injected on the housing; an insulating substrate disposed inside the housing, the insulating substrate having a conductive copper strip formed by extending the copper foil at the edge of the insulating substrate; The insulating substrate is connected to the bottom of the electrode needle through the conductive copper tape by a copper-copper bonding process.

2. The power module electrode pin internal connection structure according to claim 1, characterized in that: The insulating substrate further includes a front copper foil layer; The conductive copper tape is obtained by three-dimensional processing of the edge of the front copper foil layer.

3. The power module electrode pin internal connection structure according to claim 2, characterized in that: The insulating substrate further includes a back copper foil layer and a ceramic layer located between the front copper foil layer and the back copper foil layer.

4. The power module electrode pin internal connection structure according to claim 3, characterized in that: The ceramic layer is made of alumina ceramics.

5. The power module electrode pin internal connection structure according to claim 1, characterized in that: The conductive copper strip is made of red copper.

6. The power module electrode pin internal connection structure according to claim 1, characterized in that: The electrode needle is made of pure copper.

7. The power module electrode pin internal connection structure according to claim 1, characterized in that: The insulating substrate is a direct copper clad substrate.

8. The power module electrode pin internal connection structure according to claim 1, characterized in that: The shell is made of plastic.

9. The power module electrode pin internal connection structure according to claim 1, characterized in that: The insulating substrates include a plurality of insulating substrates, and different insulating substrates are connected by an aluminum wire bonding process.

10. A power module, characterized in that: The invention comprises the power module electrode needle internal connection structure as described in any one of claims 1 to 9.

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