A protection device for a single IGBT

Abstract

This utility model discloses a protective device for a single IGBT, including a protective shell, a mounting plate, and a pin bending sleeve. The protective shell is fastened to the single IGBT and detachably connected to the mounting plate. The front of the mounting plate contacts the heat sink on the back of the single IGBT, and a heat sink is connected to the back of the mounting plate. The pin bending sleeve is fitted over the three pins of the single IGBT. The pin bending sleeve has a T-shaped structure, and three first through holes are equally spaced on the upper surface of the T-shaped structure. The three pins of the single IGBT are inserted into the three first through holes. The lengths of the first through holes on both sides of the pin bending sleeve are equal and smaller than the length of the first through hole in the middle. This allows the pins to be matched with the solder joints in one go, avoiding repeated bending that could cause the pins to break. At the same time, during the bending process, the pin bending sleeve positions and protects the pins of the single IGBT, preventing excessive stress on the pins and chip connection points, which could lead to poor contact.

Description

Technical Field

[0001] This utility model belongs to the field of IGBT technology, specifically a protection device for a single IGBT. Background Technology

[0002] Based on packaging and application requirements, IGBTs can be divided into two main categories: single-transistor and modular. A single-transistor IGBT is packaged from a single IGBT chip, typically containing one IGBT and one freewheeling diode. It has a simple structure, small size, and is suitable for low- to medium-power applications. Meanwhile, due to the high packaging cost of modular IGBTs, inverter equipment has gradually begun to use the more cost-effective single-transistor IGBTs in recent years.

[0003] The distance between the pins of a single IGBT is only 2-3mm. In a humid environment, due to the insufficient creepage distance between the pins, short circuits such as arcing can easily occur. In addition, due to the limited heat dissipation capacity of a single IGBT, it is necessary to take necessary protection and heat dissipation measures for the single IGBT.

[0004] For example, Chinese invention patent CN106385182B discloses a fixing block for a single-tube IGBT, including a fixing part for connecting a heat sink and an mounting part for fixing the single-tube IGBT. The mounting part and the fixing part are respectively formed at both ends of the fixing block. The mounting part has a first surface and a second surface opposite to each other. A first receiving groove is provided on the first surface. The end of the first receiving groove near the fixing part is closed, and the end of the first receiving groove away from the fixing part is open. A first positioning post extending toward the first surface is provided inside the first receiving groove. This overcomes the problems of inaccurate positioning, safety hazards, and large space occupation in the existing single-tube IGBT fixing methods. Chinese invention patent document CN103839927B discloses a protective device for a single IGBT, including an insulating protective shell. The protective shell contains one or more first mounting slots, each of which has an insulating partition. The partition includes a first partition, a second partition, and a third partition arranged in parallel. The distance between the first and second partitions, and between the second and third partitions, is 2-4 mm. The first mounting slot has three through holes, located within the first, second, and third partitions respectively. Therefore, even if the voltage between any two pins of a single IGBT reaches 500-700V, or in a humid or dusty environment, the insulating partitions separate the pins, solving the problem of insufficient creepage distance between pins, preventing arcing or short circuits, and reducing the need for applying insulating varnish to the pins, thus improving product quality and work efficiency.

[0005] The aforementioned single-tube IGBT protection device requires bending the three pins of the single-tube IGBT by 90° during installation so that the three pins can pass through the through holes of the corresponding positioning components and be soldered to the external circuit. However, it is difficult to ensure that the pins match the corresponding positioning components or the corresponding solder points of the external circuit after bending. If the bending is unsuccessful the first time, repeated bending may cause the pins to be shortened. At the same time, the stress during the bending process may cause the connection between the pins and the chip to loosen, resulting in poor contact or scrapping of the single-tube IGBT. Utility Model Content

[0006] This invention proposes a protection device for a single IGBT, aiming to solve the problem that existing single IGBT protection devices are inconvenient to match with the response positioning component or external circuit soldering point during the bending of the pins.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A protective device for a single IGBT includes a protective housing, a mounting plate, and a pin bending sleeve;

[0009] The protective shell is fastened onto the single-tube IGBT and is detachably connected to the mounting plate.

[0010] The front of the mounting plate contacts the heat sink on the back of the single IGBT6, and a heat sink is connected to the back of the mounting plate.

[0011] The pin bending sleeve is fitted over the three pins of the single IGBT. The pin bending sleeve has a T-shaped structure. Three first through holes are equally spaced on the upper surface of the T-shaped structure. The three pins of the single IGBT 6 are inserted into the three first through holes. The lengths of the first through holes on both sides of the pin bending sleeve are equal and smaller than the length of the first through hole in the middle.

[0012] Preferably, positioning slots are provided on the three lower end faces of the pin bending sleeve 7. The positioning slots are aligned with the three first through holes in the width direction of the pin bending sleeve and extend into the first through holes they are aligned with. The three pins of the single IGBT are bent at 90° at the end of the first through hole and fixed in the positioning slots.

[0013] Preferably, the protective shell includes a shell, and wing plates are provided on both sides of the shell. The wing plates are provided with mounting holes and are connected to the mounting plate with screws through the mounting holes.

[0014] Preferably, the housing has downwardly extending fixing plates on both sides, the fixing plates have an L-shaped cross-section, and the inner wall of the fixing plates fits tightly with both sides of the pin bending sleeve 7.

[0015] Preferably, it also includes a pin fixing cover, which has three second through holes through which the three pins of the single IGBT pass. The pin fixing cover is snapped into the opening area formed by the fixing plate and the housing.

[0016] Preferably, the inner wall of the housing is provided with multiple spacers, and the single tube is snapped into the housing through the spacers. The inner wall of the housing is provided with a gasket, and the gasket is in contact with the plastic encapsulation surface of the single tube IGBT.

[0017] Preferably, a positioning pin is provided inside the housing, and the positioning pin extends into the positioning hole of the single-tube IGBT.

[0018] Preferably, a fan is mounted on the upper part of the heat sink.

[0019] Preferably, a silicone heat-conducting plate is provided between the mounting plate and the heat sink.

[0020] Beneficial effects:

[0021] Compared with the prior art, the present invention can achieve at least the following technical effects:

[0022] 1. This utility model features a T-shaped pin bending sleeve. The length of the through hole in the pin bending sleeve is set according to the spacing between the pin soldering points. During installation, the pin is first bent at 90° at the end of the pin bending sleeve, which allows the pin to be matched with the soldering point in one go, avoiding repeated bending that could cause the pin to break. At the same time, the pin bending sleeve also positions and protects the pins of the single IGBT during the bending process, preventing the pins from being subjected to excessive stress at the chip connection point, which could lead to poor contact.

[0023] 2. This utility model has a positioning bayonet at the end of the through hole of the pin bending sleeve. After the pin is bent, it is fixed in the positioning bayonet to further fix the pin and prevent the pin from bending or loosening under external force. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0025] Figure 2 This is an exploded view of the present invention.

[0026] Figure 3 This is a schematic diagram of the pin bending sheath structure of this utility model.

[0027] Figure 4 This is a schematic diagram of the external structure of the protective shell of this utility model.

[0028] Figure 5 This is a schematic diagram of the internal structure of the protective shell of this utility model.

[0029] Figure 6 This is a cross-sectional structural diagram of the present invention.

[0030] Figure 7 This is a schematic diagram of the pin fixing cover structure of this utility model.

[0031] In the diagram: 1. Protective shell; 101. Shell; 102. Wing plate; 103. Mounting hole; 104. Fixing plate; 105. Spacer; 106. Positioning pin; 107. Gasket; 2. Mounting plate; 201. Threaded hole; 3. Silicone heat-conducting plate; 4. Heat sink; 5. Fan; 6. Single IGBT; 7. Pin bending sleeve; 701. First through hole; 702. Positioning bayonet; 8. Pin fixing cover; 801. Second through hole. Detailed Implementation

[0032] The present invention will be further explained below with reference to specific implementation examples.

[0033] Please see Figure 1-7 This utility model proposes a protection device for a single IGBT, including a protective shell 1, a mounting plate 2, and a pin bending sleeve 7;

[0034] The protective shell 1 is fastened onto the single tube IGBT 6 and is detachably connected to the mounting plate 2;

[0035] The front of the mounting plate 2 contacts the heat sink on the back of the single IGBT 6, and the back of the mounting plate 2 is connected to a heat sink 4.

[0036] The pin bending sleeve 7 is fitted onto the three pins of the single IGBT 6. The pin bending sleeve 7 has a T-shaped structure. Three first through holes 701 are equally spaced on the upper surface of the T-shaped structure. The three pins of the single IGBT 6 are inserted into the three first through holes 701. The lengths of the first through holes 701 on both sides of the pin bending sleeve 7 are equal and smaller than the length of the first through hole 701 in the middle.

[0037] like Figure 1 , Figure 2 As shown, the protective shell 1 is used to fix the single IGBT 6 on the mounting plate 2 and to protect the single IGBT 6. The mounting plate 2 is in close contact with the heat sink on the back of the single IGBT 6 to transfer the heat generated by the single IGBT 6 to the heat sink 4, thereby improving the heat dissipation effect of the single IGBT 6.

[0038] During installation, the pin bending sleeve 7 is first placed over the three pins of the single IGBT 6. The gate and emitter pins of the single IGBT pass through the first through-holes 701 on both sides of the pin bending sleeve 7, while the collector pin passes through the middle first through-hole 701. The upper surface of the pin bending sleeve 7 contacts the root of the pins of the single IGBT 6. After the three pins pass through the corresponding through-holes 701, the three pins are bent at 90° at the end of the through-holes 701. Since the lengths of the first through-holes 701 on both sides are equal and shorter than the length of the first through-hole 701 in the middle, and the length difference between the middle first through-hole 701 and the other two first through-holes 701 is designed according to the pin soldering points, the three bent pins can just match the soldering points. At the same time, during the bending process, the pin bending sleeve 7 plays a role in positioning and protecting the pins of the single IGBT 6, preventing the pins from being subjected to excessive stress at the chip connection points, which could lead to poor contact.

[0039] In this embodiment, the pin bending sleeve 7 is further configured such that positioning slots 702 are provided on the three lower end faces of each pin bending sleeve 7. The positioning slots 702 are aligned with the three first through holes 701 in the width direction of the pin bending sleeve 7 and extend into the first through holes 701 that are aligned with them. The three pins of the single IGBT are bent at 90° at the end of the first through hole 701 and fixed in the positioning slots 702.

[0040] like Figure 3 As shown, after the pin of a single IGBT is bent at 90°, it fits perfectly into the positioning slot 702. The positioning slot 702 further fixes the pin to prevent it from bending or loosening under external force.

[0041] In this embodiment, the protective shell 1 is further configured to include a shell 101, with wing plates 102 on both sides of the shell 101. The wing plates 102 are provided with mounting holes 103 and are connected to the mounting plate 2 with screws through the mounting holes 103.

[0042] like Figure 4 As shown, after installing the pin bending sleeve 7 and bending the pins of the single IGBT, the protective shell 1 is then fastened onto the single IGBT 6. The screws are passed through the mounting holes 103 on the wing plate 102 and tightened into the threaded holes 201 on the mounting plate 2, so that the protective shell 1 fixes the single IGBT 6 onto the mounting plate 2.

[0043] In this embodiment, the housing 101 is further configured with downwardly extending fixing plates 104 on both sides. The fixing plates 104 have an L-shaped cross-section, and the inner wall of the fixing plates 104 is tightly fitted with both sides of the pin bending sleeve 7.

[0044] The fixing plate 104 is in close contact with both sides of the pin bending sleeve 7 by the inner wall of the side of the fixing plate 104, and the fixing plate 104 is parallel to the inner wall of the mounting plate 2 to press the front surface of the pin bending sleeve 7, thereby fixing the pin bending sleeve 7.

[0045] This embodiment is further configured to include a pin fixing cover 8, which has three second through holes 801. The three pins of the single IGBT pass through the three second through holes 801, and the pin fixing cover 8 is snapped into the opening area formed by the fixing plate 104 and the housing 101.

[0046] like Figure 7 As shown, the pin fixing cover 8 is clamped onto the protective shell 1 by interference fit, which further fixes the three pins and prevents dust from entering the first through hole 701 of the protective shell 1 and the pin bending sleeve 7.

[0047] In this embodiment, a plurality of spacers 105 are provided on the inner wall of the housing 101, and the single IGBT is snapped into the housing 101 through the spacers 105. A gasket 107 is provided on the inner wall of the housing 101, and the gasket 107 is in contact with the surface of the plastic encapsulation of the single IGBT 6.

[0048] like Figure 5 , Figure 6 As shown, the material of the gasket 107 is a flexible material such as silicone or rubber, which allows the protective shell 1 to make flexible contact with the single tube IGBT6, preventing the single tube IGBT6 from being crushed during the installation of the protective shell, and also has a first-class anti-vibration effect.

[0049] The spacer bar is in close contact with the outer contour of the single IGBT6 tube, which serves to limit the movement of the single IGBT6 tube.

[0050] In this embodiment, a positioning pin 106 is provided inside the housing 101, and the positioning pin 106 extends into the positioning hole of the single tube IGBT 6.

[0051] Currently, most mainstream single-tube IGBT packages have a positioning hole. By setting a positioning pin 106, which cooperates with the positioning hole of the single-tube IGBT6, the single-tube IGBT6 can be further fixed.

[0052] In this embodiment, a fan 5 is further configured to be mounted on the upper part of the heat sink 4.

[0053] By setting up fan 5, air is forced to circulate in the gaps between the fins of heat sink 4, thereby improving the heat dissipation effect.

[0054] In this embodiment, a silicone heat-conducting plate 3 is provided between the mounting plate 2 and the heat sink 4.

[0055] By setting up the silicone heat-conducting plate 3, the heat transfer efficiency between the mounting plate 2 and the heat sink 4 can be improved. Compared with directly mounting the single IGBT 6 on the heat sink, the silicone heat-conducting plate 3 can also play an insulating role, preventing the heat sink 4 from contacting the leakage part and breaking down the single IGBT.

[0056] It should be noted that this embodiment takes the currently used three-pin IGBT as an example. For a four-pin single-tube IGBT, the structure of the pin bending sleeve 7 and the pin fixing cover 8 can be adapted to achieve the same protection.

[0057] In the description of this utility model, the term "multiple" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0058] In the description of this utility model, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this utility model, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

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