IGBT (Insulated Gate Bipolar Translator) module, welding equipment and packaging welding method

Abstract

The invention relates to the field of semiconductor packaging, and particularly discloses an IGBT (Insulated Gate Bipolar Translator) module, welding equipment and a packaging welding method. The IGBT module comprises a chip unit and a packaging structure, wherein the packaging structure comprises a substrate and electrode pins; the electrode pin comprises a pin body and a pin seat which are integrally arranged, and the pin seat is connected with the substrate; the needle body comprises a buffer subsection and an installation subsection, the buffer subsection is connected with the needle seat, and a stop block is arranged on the installation subsection; the buffering subsection is bent towards one side, and the maximum bending distance of the buffering subsection is larger than the extending distance of the check block in the same direction. The IGBT module can well give consideration to damping performance, assembly convenience and quality reliability, and has good practical value.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging, and more particularly to an IGBT module, welding equipment, and packaging welding method. Background Technology

[0002] An Insulated Gate Bipolar Transistor (IGBT) is a composite power semiconductor device that combines the advantages of a power MOSFET and a bipolar junction transistor (BJT), serving as the core execution unit in power electronic systems. IGBTs are widely used in new energy, industrial control, and rail transportation, for example, supporting motor drives and charging pile power conversion in new energy vehicles, achieving AC / DC conversion in photovoltaic and wind power systems, and in industrial frequency converters and rail transit traction converters. Currently, chips are evolving towards trench gate and field-stop structures, and packaging is developing towards higher density to continuously adapt to high power density requirements.

[0003] The IGBT package structure mainly consists of a chip unit, a substrate, electrode leads, a package shell, and a heat dissipation layer. The chip unit is bonded to the substrate, which is often a DBC ceramic substrate (ceramic layer + metal layer), providing both electrical insulation and heat dissipation. The chip electrodes are connected to the electrode leads via metal bonding wires, enabling external circuit conduction. The package shell, made of materials such as epoxy resin, covers the chip and bonding wires, isolating them from moisture and dust. A metal heat dissipation layer (such as a copper base) is often located at the bottom, along with thermal grease to enhance heat conduction.

[0004] PIN pins (electrode pins) are the core metal components connecting IGBT modules to external circuits, undertaking the dual functions of power transmission and signal control. There are two main types of PIN pins used in IGBT power module packaging: integrated pins and separate pins. For example, Chinese invention patent application CN 104009309 A discloses a leak-proof automotive connector pin, in which the PIN pin is an integrated pin. Integrated pins generally have poor shock resistance and weak stress resistance, making them prone to failure during use. Separate pins are those where the pin holder and pin body are separate. The pin holder is soldered to the DBC, and the pin body is inserted into the pin holder. For example, Chinese invention patent application CN 115528460 A discloses a method for manufacturing a power module, a PIN pin structure, and its manufacturing method, in which the PIN pin is a separate structure. Separate pins can effectively prevent shock and resist stress, but the manufacturing process of separate pins requires high precision in the soldering position of the pin holder. Excessive misalignment can prevent the pin body from being inserted, resulting in assembly difficulties and a low product yield. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an IGBT module, welding equipment and packaging welding method that can well balance shock absorption, assembly convenience and quality reliability, and has great practical value.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an IGBT module, comprising a chip unit and a packaging structure, wherein the packaging structure comprises a substrate and electrode pins; the electrode pins comprise an integrally formed pin body and pin seat, wherein the pin seat is connected to the substrate; the pin body comprises a buffer segment and an mounting segment, wherein the buffer segment is connected to the pin seat, and the mounting segment is provided with a stop; the buffer segment is bent to one side, and the maximum bending distance of the buffer segment is greater than the extension distance of the stop in the same direction.

[0007] The bent buffer segments can cushion external loads through elastic deformation, effectively resisting vibration and impact, preventing soldering failure, and improving service life. Meanwhile, the integrated pin holder and pin body reduce assembly difficulty and improve connection reliability. The stop not only assists in positioning during encapsulation soldering but also positions and prevents molding compound from entering the casing during subsequent molding. The fact that the bending distance of the buffer segments is greater than the extension distance of the stop provides directional guidance for the electrode pins' alignment with the substrate, ensuring accurate pin mounting.

[0008] The IGBT module of this application can effectively balance vibration reduction, ease of assembly, and reliability, and has great practical value.

[0009] Preferably, the mounting segments of the needle body extend in a straight line and are perpendicular to and aligned with the needle base. This effectively avoids excessive bending moments in the mounting segments under load, further improving the reliability of the connection.

[0010] Preferably, the needle holder has a rectangular cross-section; the lower end of the buffer segment is connected to the side of the needle holder, and the width of the buffer segment is not greater than the width of the corresponding side of the needle holder.

[0011] The large contact area between the pin holder and the substrate ensures a reliable connection. Furthermore, the buffer segment extends to the side and connects to the pin holder, reducing abrupt shape changes between the buffer segment and the pin holder, minimizing stress concentration, and improving mechanical properties.

[0012] Preferably, the projection of the stop block onto the plane of the needle hub completely covers the needle hub; the stop block is made of resin material. The stop block can provide excellent protection for the needle hub.

[0013] Preferably, the cross-section of the stop is circular; the maximum bending distance of the buffer segment is greater than the radius of the stop. A welding device for IGBT module packaging includes a base and a pin positioning module. The upper surface of the base is provided with a mounting groove, and the pin positioning module is detachably connected to the base. The pin positioning module includes a first positioning plate and a second positioning plate, which are separately arranged and stacked sequentially. The first positioning plate has a plurality of through-holes, and the second positioning plate has a plurality of through-channels. Each positioning hole is aligned with one of the guide channels. The guide channels extend to one side of the second positioning plate, and the maximum width of the positioning hole is greater than the width of the guide channel. The positioning hole has a directional notch on one side, which extends vertically through the first positioning plate and is aligned with the guide channel.

[0014] The base is used for mounting and positioning the substrate. The positioning holes of the first positioning plate match the shape of the stop block for horizontal positioning of the electrode leads. The second positioning plate contacts the lower end face of the stop block to achieve vertical positioning of the electrode leads. The guide channel not only provides space for the installation of the pin holder but also provides a channel for solder coating. The guide channel extends horizontally to the side of the second positioning plate, providing conditions for the horizontal removal of the second positioning plate. During the process of the pin holder and buffer segment passing through the positioning holes, the buffer segment must be aligned with the orientation notch for smooth insertion, indicating the installation direction of the electrode leads and preventing incorrect installation orientation of the electrode leads relative to the substrate. In the soldering operation, the electrode leads only need to be inserted sequentially through the positioning holes and guide channels to achieve accurate positioning, resulting in high operational efficiency.

[0015] The welding equipment described in this application has the advantages of simple structure, reliable positioning, convenient operation, and high welding efficiency.

[0016] Preferably, a plurality of docking components are provided between the base and the first positioning plate. Each docking component includes a corresponding docking pin and a docking hole. One of the docking pins and docking holes is located on the upper surface of the base, and the other is located on the first positioning plate.

[0017] Preferably, a limiting groove is formed on the lower surface of the first positioning plate, and the width of the limiting groove is not less than the width of the second positioning plate; a connecting component is also provided between the first positioning plate and the second positioning plate, the connecting component including a connecting protrusion and a connecting groove, one of the connecting protrusion and the connecting groove being provided on the first positioning plate and the other being provided on the second positioning plate.

[0018] The limiting groove and the connecting component work together to achieve relative positioning and limiting of the first positioning plate and the second positioning plate, ensuring that the relative position between the positioning hole and the guide channel is accurate and reliable, and also ensuring that the relative position between the guide channel and the substrate is accurate and reliable.

[0019] Preferably, the second positioning plate includes several partitions along its width, each partition having a guide channel, the guide channels in each partition having the same length and being at least 0.8 times the length of the second positioning plate.

[0020] The standardized distribution of the guide channels enables standardized processing of the second positioning plate. For substrates of the same size but different models, only the first positioning plate needs to be replaced, effectively reducing the number of equipment and lowering changeover processing costs. A packaging and soldering method for an IGBT module as described above, using the soldering equipment described above; At least the following steps are included: S1. Substrate mounting: Insert the substrate into the mounting slot of the base, and then connect the pin positioning module to the base; S2. Electrode pin pre-installation: Solder is applied sequentially to the corresponding areas of the substrate through each positioning hole and the corresponding guide channel; then the electrode pin holders are inserted through each positioning hole and the corresponding guide channel and connected to the substrate through solder; during the insertion of the electrode pins, the orientation of the bending segments is aligned with the positioning notches; At this time, the stop block is located inside the positioning hole, and the lower end face of the stop block is in contact with the upper surface of the second positioning plate. S3. Welding and forming: The welding equipment, substrate and electrode leads are heated as a whole, and the electrode leads and substrate are welded together with solder. S4. Unloading: Lift the first positioning plate upwards along the extension direction of the installation segment and remove it. Then move the second positioning plate horizontally along the opening direction of the guide channel and remove it. Remove the completed substrate and electrode pins from the base as a whole to complete the single encapsulation welding operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the IGBT module in this embodiment; Figure 2 This is a schematic diagram of the electrode pin structure in the IGBT module of this embodiment; Figure 3 This is a front view of the electrode pins in the IGBT module of this embodiment; Figure 4 This is a schematic diagram of the welding equipment used for IGBT module packaging in this embodiment; Figure 5 This is a front sectional view of the welding equipment used for IGBT module packaging in this embodiment; Figure 6 for Figure 5 A magnified view of a section at point A in the middle; Figure 7 This is a side sectional view of the welding equipment used for IGBT module packaging in this embodiment; Figure 8 This is an exploded view of the welding equipment used for IGBT module packaging in this embodiment; Figure 9 This is a schematic diagram of the pin positioning module in the welding equipment used for IGBT module packaging in this embodiment; Figure 10 This is a schematic diagram of the pin positioning module in the welding equipment used for IGBT module packaging in this embodiment from another perspective; Figure 11 This is a schematic diagram of the structure of the second positioning plate in the welding equipment used for IGBT module packaging in this embodiment; Figure 12 This is a schematic diagram of the second form of the welding equipment used for IGBT module packaging in this embodiment. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Example

[0023] like Figure 1 As shown, an IGBT module includes a chip unit and a packaging structure, wherein the packaging structure includes a substrate 1 and electrode pins 2.

[0024] like Figures 1-3 As shown, the electrode pin 2 includes an integrally formed needle body and needle base 24, with the needle base 24 connected to the substrate 1. The needle body includes a buffer segment 23 and a mounting segment 21. The buffer segment 23 is connected to the needle base 24, and the mounting segment 21 is provided with a stop 22. The buffer segment 23 is bent to one side, and the maximum bending distance of the buffer segment 23 is greater than the extension distance of the stop 22 in the same direction. Figure 3 As shown, the extension distance of the stop 22 is denoted as D, and the maximum bending distance of the buffer segment 23 is denoted as L. Then, L > D.

[0025] Specifically, such as Figure 2 and Figure 3 As shown, the mounting segment 21 of the needle body extends in a straight line and is perpendicular to and aligned with the needle base 24. This effectively avoids excessive bending moment in the mounting segment 21 under load, further improving the reliability of the connection.

[0026] Specifically, such as Figure 2 and Figure 3 As shown, the needle holder 24 has a rectangular cross-section. The lower end of the buffer segment 23 is connected to the side of the needle holder 24, and the width of the buffer segment 23 is no greater than the width of the corresponding side of the needle holder 24. The contact surface between the needle holder 24 and the substrate 1 is large, ensuring a reliable connection. The buffer segment 23 extends to the side and connects to the needle holder 24, which reduces the abrupt shape change between the buffer segment 23 and the needle holder 24, reduces stress concentration, and improves mechanical properties.

[0027] Specifically, such as Figure 2 and Figure 3 As shown, the projection of the stop 22 onto the plane containing the needle holder 24 completely covers the needle holder 24. The stop 22 is made of resin material. The stop 22 provides excellent protection for the needle holder 24.

[0028] Specifically, such as Figure 2 and Figure 3 As shown, the cross-section of the stop 22 is circular; the maximum bending distance of the buffer segment 23 is greater than the radius of the stop 22.

[0029] The bent buffer segment 23 can buffer external loads through elastic deformation, effectively resisting vibration and impact, preventing welding failure, and improving service life. Meanwhile, the integrated pin holder 24 and pin body reduce assembly difficulty and improve connection reliability. The stop 22 not only assists in positioning during encapsulation welding but also positions and prevents molding compound from entering the interior during subsequent molding process. The bending distance of the buffer segment 23 being greater than the extension distance of the stop 22 serves as an indicator of the orientation of the electrode pin 2 in relation to the substrate 1, ensuring accurate installation of the electrode pin 2.

[0030] The IGBT module of this application can effectively balance vibration reduction, ease of assembly, and reliability, and has great practical value. like Figures 4-8 As shown, a welding device for IGBT module packaging includes a base 3 and a pin positioning module 4. The upper surface of the base 3 is provided with a mounting groove 31, and the pin positioning module 4 is detachably connected to the base 3.

[0031] like Figures 4-8 As shown, the pin positioning module 4 includes a first positioning plate 41 and a second positioning plate 42. The first positioning plate 41 and the second positioning plate 42 are separately arranged and stacked in sequence.

[0032] like Figures 8-10As shown, the first positioning plate 41 has a plurality of through-holes 412 distributed on it, and the second positioning plate 42 has a plurality of through-holes 421 distributed on it. Each positioning hole 412 is aligned with one of the guide channels 421, and the guide channel 421 extends to one side of the second positioning plate 42.

[0033] like Figures 8-10 As shown, a directional notch is provided on one side of the positioning hole 412. The directional notch extends vertically through the first positioning plate 41 and is aligned with the guide channel 421. During the process of the pin holder and the buffer segment passing through the positioning hole, the buffer segment must be aligned with the directional notch to be inserted smoothly. This serves as an indicator of the installation direction of the electrode pins and prevents the electrode pins from being installed in the wrong direction relative to the substrate.

[0034] like Figures 8-10 As shown, the maximum width of the positioning hole 412 is greater than the width of the guide channel 421. Specifically, the cross-section of the positioning hole 412 is circular, and the diameter of the positioning block is greater than the width of the guide channel 421.

[0035] Specifically, such as Figure 8 As shown, a plurality of docking components are provided between the base 3 and the first positioning plate 41. Each docking component includes a corresponding docking pin 32 and a docking hole 411. One of the docking pins 32 and the docking holes 411 is provided on the upper surface of the base 3, and the other is provided on the first positioning plate 41.

[0036] Specifically, such as Figure 9 and Figure 10 As shown, a limiting groove 414 is formed on the lower surface of the first positioning plate 41, and the width of the limiting groove 414 is not less than the width of the second positioning plate 42. A connecting assembly is also provided between the first positioning plate 41 and the second positioning plate 42. The connecting assembly includes a connecting protrusion 413 and a connecting groove 422. One of the connecting protrusion 413 and the connecting groove 422 is provided on the first positioning plate 41, and the other is provided on the second positioning plate 42.

[0037] The limiting groove 414 and the connecting component work together to achieve relative positioning and limiting of the first positioning plate 41 and the second positioning plate 42, ensuring that the relative position between the positioning hole 412 and the guide channel 421 is accurate and reliable, and at the same time, it can also ensure that the relative position between the guide channel 421 and the substrate 1 is accurate and reliable.

[0038] The base 3 is used for mounting and positioning the substrate 1. The positioning hole 412 of the first positioning plate 41 matches the shape of the stop 22 for horizontal positioning of the electrode pin 2. The second positioning plate 42 is used to contact the lower end face of the stop 22 to achieve vertical positioning of the electrode pin 2. The guide channel 421 not only provides space for the installation of the pin holder 24, but also provides a channel for the coating of solder. The guide channel 421 extends horizontally to the side of the second positioning plate 42, providing conditions for the horizontal removal of the second positioning plate 42.

[0039] As a specific implementation method, such as Figure 11 As shown, the length of the guide channel is specifically set according to the setting position of the corresponding positioning hole.

[0040] As another specific implementation method, such as Figure 12 As shown, the second positioning plate 42 includes several partitions along the width direction, and each partition is provided with a guide channel 421. The guide channel 421 in each partition has the same length and is at least 0.8 times the length of the second positioning plate 42.

[0041] The standardized distribution of the guide channel 421 allows for standardized processing of the second positioning plate 42. For different models of the same size substrate 1, only the first positioning plate 41 needs to be replaced, effectively reducing the number of equipment and lowering changeover processing costs.

[0042] The welding equipment described in this application has the advantages of simple structure, reliable positioning, and convenient operation. A packaging and soldering method for an IGBT module as described above, using the soldering equipment described above; At least the following steps are included: S1. Mounting of substrate 1: Insert substrate 1 into mounting slot 31 of base 3, and then connect pin positioning module 4 to base 3; S2. Electrode pin 2 pre-installation: Solder is applied sequentially from each positioning hole 412 and the corresponding guide channel 421 to the corresponding area of ​​the substrate 1; then the pin seat 24 of the electrode pin 2 is inserted from each positioning hole 412 and the corresponding guide channel 421 and connected to the substrate 1 by solder; during the insertion of the electrode pin 2, the orientation of the bent segment is aligned with the positioning notch. At this time, the stop block 22 is located inside the positioning hole 412, and the lower end face of the stop block 22 is in contact with the upper surface of the second positioning plate 42. S3. Welding and forming: The welding equipment, substrate 1 and electrode pins 2 are heated as a whole, and electrode pins 2 and substrate 1 are welded together with solder. S4. Unloading: Lift the first positioning plate 41 upward along the extension direction of the mounting segment 21 and remove it. Then move the second positioning plate 42 horizontally along the opening direction of the guide channel 421 and remove it. Remove the completed substrate 1 and electrode pin 2 from the base 3 as a whole to complete the single encapsulation welding operation.

[0043] In summary, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An IGBT module, comprising a chip unit and a packaging structure, wherein the packaging structure includes a substrate and electrode leads; characterized in that: The electrode pin includes an integrally formed needle body and needle base, the needle base being connected to the substrate; the needle body includes a buffer segment and an mounting segment, the buffer segment being connected to the needle base, and the mounting segment having a stop; the buffer segment is bent to one side, and the maximum bending distance of the buffer segment is greater than the extension distance of the stop in the same direction.

2. The IGBT module according to claim 1, characterized in that: The mounting segments of the needle body extend in a straight line and are perpendicular to and aligned with the needle base.

3. The IGBT module according to claim 2, characterized in that: The needle hub has a rectangular cross-section; the lower end of the buffer segment is connected to the side of the needle hub, and the width of the buffer segment is not greater than the width of the corresponding side of the needle hub.

4. The IGBT module according to claim 1, characterized in that: The projection of the stop block onto the plane where the needle holder is located completely covers the needle holder; the stop block is made of resin material.

5. The IGBT module according to any one of claims 1-4, characterized in that: The cross-section of the stop block is circular; the maximum bending distance of the buffer segment is greater than the radius of the stop block.

6. A welding device for IGBT module packaging, characterized in that: It includes a base and a pin positioning module. The upper surface of the base is provided with a mounting groove, and the pin positioning module is detachably connected to the base. The pin positioning module includes a first positioning plate and a second positioning plate, which are separately arranged and stacked sequentially. The first positioning plate has a plurality of through-holes, and the second positioning plate has a plurality of through-channels. Each positioning hole is aligned with one of the guide channels. The guide channels extend to one side of the second positioning plate, and the maximum width of the positioning hole is greater than the width of the guide channel. The positioning hole has a directional notch on one side, which extends vertically through the first positioning plate and is aligned with the guide channel.

7. The welding equipment according to claim 6, characterized in that: The base and the first positioning plate are provided with a plurality of docking components. The docking components include one-to-one docking pins and docking holes. One of the docking pins and docking holes is provided on the upper surface of the base, and the other is provided on the first positioning plate.

8. The welding equipment according to claim 6, characterized in that: A limiting groove is formed on the lower surface of the first positioning plate, and the width of the limiting groove is not less than the width of the second positioning plate; a connecting component is also provided between the first positioning plate and the second positioning plate, the connecting component including a connecting protrusion and a connecting groove, one of the connecting protrusion and the connecting groove being provided on the first positioning plate and the other being provided on the second positioning plate.

9. The welding equipment according to any one of claims 6-8, characterized in that: The second positioning plate includes several partitions along its width, each partition having a guide channel. The guide channels in each partition have the same length and are at least 0.8 times the length of the second positioning plate.

10. A packaging and soldering method for an IGBT module as described in any one of claims 1-5, characterized in that: The welding equipment as described in any one of claims 6-9 is used; At least the following steps are included: S1. Substrate mounting: Insert the substrate into the mounting slot of the base, and then connect the pin positioning module to the base; S2. Electrode pin pre-installation: Solder is applied sequentially to the corresponding areas of the substrate through each positioning hole and the corresponding guide channel; then the electrode pin holders are inserted through each positioning hole and the corresponding guide channel and connected to the substrate through solder; during the insertion of the electrode pins, the orientation of the bending segments is aligned with the positioning notches; At this time, the stop block is located inside the positioning hole, and the lower end face of the stop block is in contact with the upper surface of the second positioning plate. S3. Welding and forming: The welding equipment, substrate and electrode leads are heated as a whole, and the electrode leads and substrate are welded together with solder. S4. Unloading: Lift the first positioning plate upwards along the extension direction of the installation segment and remove it. Then move the second positioning plate horizontally along the opening direction of the guide channel and remove it. Remove the completed substrate and electrode pins from the base as a whole to complete the single encapsulation welding operation.

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