Gate structure applied to crimping type mosfet

Abstract

A gate structure applied to a crimping type MOSFET, comprising a first copper block, a crimping type MOSFET, a gate connecting piece, a connecting interface receiving an external gate control signal, a second copper block, a rod-shaped metal in contact with the gate of the crimping type MOSFET, an elastic structure for connecting the rod-shaped metal with the gate connecting piece, and an insulating medium between the gate connecting piece and the second copper block. Using the above-mentioned gate structure without blocking the heat dissipation path of the MOSFET, the heat dissipation capacity can be improved, and the crimping structure is simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to a gate structure of MOSFET, in particular to a gate structure applied to a crimping type MOSFET or a crimping type MOSFET array, and belongs to the technical field of electrical engineering. BACKGROUND

[0002] Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET for short, is a kind of field effect transistor that can be widely used, which can be applied to digital signal processing occasions such as microprocessors, microcontrollers, and more and more analog signal processing integrated circuits are realized by MOSFET.

[0003] The traditional MOSFET is a lateral through-flow structure, and its gate, drain and source are usually welded on the circuit board. The heat generated during the operation of the device is mainly dissipated through the circuit board. Due to the influence of the packaging type, the heat dissipation capacity is poor, which limits the through-flow capacity. The crimping type MOSFET, as shown in Figure 1 , is a longitudinal through-flow structure. The drain is a top metal shell. During use, the bottom source and gate can be welded with the circuit board, and the left and right side drains are welded with the circuit board. The top drain is crimped with a metal connection structure to increase the heat dissipation capacity.

[0004] In some applications, the crimping type MOSFET die is directly used for crimping without packaging structure, as shown in Figure 2 .

[0005] In high-power applications, a large number of MOSFETs are usually used in parallel to form an array to realize the functions of large current conduction and turn-off. For example, the turn-off module of the gate drive circuit of the integrated gate-commutated thyristor (IGCT), as shown in Fig. 3(a), uses a large number of parallel MOSFET arrays Q G and a pre-charged parallel capacitor group C off in series. During the IGCT turn-off period, the MOSFET array Q G is turned on by triggering, so that the cathode current of the IGCT is commutated to the gate, thereby turning off the IGCT. For another example, in the drive circuit of the emitter turn-off thyristor (ETO) based on GCT or GTO element, as shown in Fig. 3(b), two groups of parallel MOSFET arrays Q G and Q E are used. During the ETO conduction period, Q G is turned off, and Q E is turned on; during the ETO turn-off period, Q E is turned off, and Q GConducting, the current is commutated from the cathode to the gate of the GCT or GTO element, so that it is turned off.

[0006] For the above-mentioned application, in order to improve the commutation speed of the turn-off device current commutated from the cathode to the gate, the stray inductance of the loop should be reduced as much as possible, for this purpose, the MOSFET should be integrated in the device tube shell package. In the existing press-fit structure, the press-fit MOSFET is generally welded on the multi-layer circuit board, and then the gate control signal of the MOSFET is conducted from the outside to the MOSFET gate through the multi-layer circuit board. But the introduction of multi-layer circuit board will block the process of heat transfer from MOSFET to the outside.

[0007] In addition, since the molybdenum sheet needs to be press-fitted on both sides of the GCT or GTO when it is used, and a pressure of several tens of KN or more needs to be applied, and a single press-fit MOSFET can only withstand a pressure of 50-100N, therefore, if the press-fit MOSFET is integrated in the tube shell, there are problems of pressure difference and cooperation of different components. SUMMARY

[0008] In order to overcome the defects of the prior art, the application provides a gate structure applied to a press-fit MOSFET, which uses a gate structure that does not block the heat dissipation path of the MOSFET, thereby improving the heat dissipation capability.

[0009] The technical scheme is as follows:

[0010] A gate structure applied to a press-fit MOSFET, characterized in that it comprises a first copper block, a press-fit MOSFET, a gate connecting piece, a connecting interface for receiving an external gate control signal, a second copper block, an elastic structure, a rod-shaped metal in contact with the gate of the press-fit MOSFET, and an insulating medium between the gate connecting piece and the second copper block.

[0011] The source of the press-fit MOSFET is connected to the protruding part of the second copper block.

[0012] The gate connecting piece is placed in the groove of the second copper block and is electrically insulated from the second copper block by the insulating medium.

[0013] The gate connecting piece and the gate of the press-fit MOSFET are connected through the elastic structure and the rod-shaped metal.

[0014] The gate connecting piece is connected to the connecting interface and receives an external gate control signal.

[0015] Further, the first copper block includes one or more, each of the first copper blocks is at the same potential as the drain of the crimp type MOSFET, the second copper block includes one or more, each of the second copper blocks is at the same potential as the source of the crimp type MOSFET; wherein the first copper block and the second copper block have a certain pressure between them.

[0016] Further, the crimp type MOSFET includes a plurality and forms a crimp type MOSFET array; the shape of the gate connection is set according to the arrangement of the crimp type MOSFET array.

[0017] Further, the crimp type MOSFET array adopts a ring shape or a matrix shape; when all crimp type MSOFETs in the array are controlled using the same gate signal, then one of the gate connections is used to electrically connect all crimp type MSOFETs, and when different gate signals are used to control the crimp type MSOFETs in the array, then different gate connections are used to electrically connect the corresponding crimp type MSOFETs.

[0018] Further, the gate connection and the gate of the crimp type MOSFET are connected through the elastic structure and the rod-shaped metal, and the elastic structure ensures reliable connection of the rod-shaped metal and the gate of the crimp type MOSFET.

[0019] A gate structure applied to a crimp type MOSFET die, characterized by comprising a first copper block, a crimp type MOSFET die, a gate connection, a connection interface for receiving an external gate control signal, a second copper block, an elastic structure, and a rod-shaped metal in contact with the gate of the crimp type MOSFET die.

[0020] The first copper block is connected to the drain of the crimp type MOSFET die, and the second copper block is connected to the source of the crimp type MOSFET die.

[0021] The gate connection is placed in the groove of the second copper block.

[0022] The gate connection and the gate of the crimp type MOSFET are connected through the elastic structure and the rod-shaped metal.

[0023] The gate connection is connected to the connection interface and receives an external gate control signal.

[0024] Further, the first copper block includes one or more, each of the first copper blocks is at the same potential as the drain of the crimp type MOSFET die, the second copper block includes one or more, each of the second copper blocks is at the same potential as the source of the crimp type MOSFET die; wherein the first copper block and the second copper block have a certain pressure between them.

[0025] Further, the crimping type MOSFET dies include a plurality of and form a crimping type MOSFET die array; the shape of the gate connecting piece is set according to the arrangement mode of the crimping type MOSFET die array.

[0026] Further, the crimping type MOSFET die array adopts a ring shape or a matrix shape; when all the crimping type MOSFET dies in the array are controlled by using the same gate signal, one gate connecting piece is used to electrically connect all the crimping type MOSFET dies; when the crimping type MOSFET dies in the array are controlled by using different gate signals, different gate connecting pieces are used to electrically connect the corresponding crimping type MOSFET dies.

[0027] Further, the gate connecting piece is connected with the gate of the crimping type MOSFET die through the elastic structure and the rod-shaped metal, and the elastic structure ensures reliable connection between the rod-shaped metal and the gate of the crimping type MOSFET.

[0028] Compared with the prior art, the crimping structure applied to the crimping type MOSFET array has the following beneficial effects:

[0029] (1) The gate structure is suitable for the parallel array of the crimping type MOSFET, and has simple and compact structure.

[0030] (2) The ring-shaped or grid-shaped gate connecting piece does not affect the connection between the first copper block, the second copper block and the MOSFET, and a certain pressure can be applied between the first copper block and the second copper block, so as to reduce the contact surface resistance and thermal resistance.

[0031] (3) The gate connecting piece is connected with the gate of the MOSFET through the elastic structure and the rod-shaped metal, so that a certain pressure is ensured at the connection position, reliable connection is ensured, and the MOSFET is not damaged due to excessive pressure. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The crimping type MOSFET structure of the prior art;

[0033] Figure 2 The MOSFET die without packaging structure of the prior art;

[0034] Figure 3a The turn-off module of the gate drive circuit of the integrated gate-commutated thyristor (IGCT) of the prior art;

[0035] Figure 3b The drive circuit of the emitter turn-off thyristor (ETO) based on the GCT or GTO element of the prior art;

[0036] Figure 4 An embodiment of the gate structure of the application applied to the crimping type MOSFET array;

[0037] Figure 5 Another embodiment of the gate structure of the application applied to the crimping type MOSFET array;

[0038] Figure 6 The annular crimping type MOSFET array of the application applied to the crimping type MOSFET array;

[0039] Figure 7 The gate connecting member of the annular crimping type MOSFET array of the application;

[0040] Figure 8 The matrix-shaped crimping type MOSFET array of the application applied to the crimping type MOSFET array;

[0041] Figure 9 The gate connecting member of the matrix-shaped crimping type MOSFET array of the application. DETAILED DESCRIPTION

[0042] The application will be described in detail below with reference to the accompanying drawings and specific embodiments, but not as a limitation to the application.

[0043] In one embodiment, the crimping type MOSFET with the gate structure has a crimping structure as shown in Figure 4 which includes a first copper block 41, a crimping type MOSFET 42, a gate connecting member 43, a connecting interface 44 receiving an external gate control signal, a second copper block 45, an elastic structure 46, a rod-shaped metal 47 in contact with the gate of the crimping type MOSFET 42, and an insulating medium 48 between the gate connecting member 43 and the second copper block 45; wherein the gate connecting member 43 can be in the form of a gate ring or a grid.

[0044] The first copper block 41 is at the same potential as the drain of the crimping type MOSFET 42, and the second copper block 45 is at the same potential as the source of the crimping type MOSFET 42.

[0045] The first copper block 41 and the second copper block 45 have a certain pressure therebetween, which is used to reduce the contact resistance and thermal resistance of the contact surface between the first copper block 41 and the crimping type MOSFET 42.

[0046] The source of the crimping type MOSFET 42 is connected to the protruding part of the second copper block 45, which can be connected by crimping or welding.

[0047] The gate connecting member 43 is placed in the groove of the second copper block 45 and is electrically insulated from the second copper block 45.

[0048] The gate connecting member 43 is connected to the gate of the crimping MOSFET 42 through an elastic structure 46 and a rod-shaped metal 47. The elastic structure 46 can ensure reliable contact between the rod-shaped metal 47 and the gate of the crimping MOSFET 42, and can avoid excessive or insufficient contact stress caused by size matching problems.

[0049] The gate connecting member 43 is connected to the connecting interface 44 to receive an external gate control signal. The connecting interface 44 is, for example, a coaxial cable.

[0050] The gate connecting member 43 can be a metal structure. Since it is placed in the groove of the second copper block 45, an insulating medium 48 is needed for electrical isolation. The gate connecting member 43 can also be a circuit board with an electrically isolated surface.

[0051] For the metal structure of the gate connecting member 43, the upper surface has a groove for the position fixation of the rod-shaped metal 47. For the gate connecting member 43 of the circuit board, a cylindrical structure can be used to connect with the positioning hole of the circuit board, and then the rod-shaped metal 47 is placed in the cylindrical structure.

[0052] In one embodiment, the gate structure of the crimping MOSFET die is as shown in Figure 5 The first copper block can be the same as Figure 4 and a separate copper block is used. Considering that the crimping MOSFET die is not affected by the packaging structure, the pressure is not limited to 50-100 N, so a whole first copper block 51 can also be used as shown in Figure 5 and a larger pressure, such as tens of kN, is applied.

[0053] Since the drain of the crimping MOSFET die 52 is above the crimping MOSFET die 52, and only the source and the gate are below, the second copper block 55 only needs to be grooved according to the shape of the gate connecting member 53, without considering electrical insulation with the drain. The connection structure of the gate connecting member 53 and the gate of the crimping MOSFET die 52 is similar to Figure 4 The gate connecting member 53 is connected to the gate of the crimping MOSFET die 52 through an elastic structure 56 and a rod-shaped metal 57.

[0054] In Figure 5 , since the first copper block 51 is directly connected to the drain of the crimping MOSFET die 52, the second copper block 55 is directly connected to the source of the crimping MOSFET die 52, and there is a certain pressure between the first copper block 51 and the second copper block 55, the gate connecting member 53 can be arranged in a ring or grid shape, occupying only a small space of the second copper block 55, so as to ensure good electrical contact and low thermal resistance of the MOSFET heat dissipation path to the upper and lower surfaces.

[0055] In one embodiment, the shape of the gate connection can be designed according to the arrangement of the crimped MOSFET array. For a ring-shaped crimped MOSFET array, as shown in FIG. 1, one design of the gate connection is shown in FIG. 2. If the inner and outer rings of the crimped MOSFETs are controlled by the same gate signal, the inner and outer rings of the gate connection are electrically connected. If the middle ring is controlled by a different gate signal, a different gate connection is used. Figure 6 Figure 7 For a matrix-shaped crimped MOSFET array, as shown in FIG. 3, if all the crimped MOSFETs are controlled by the same gate signal, one design of the gate connection is shown in FIG. 4. If the crimped MOSFETs are controlled by different gate signals, the design idea is the same as that of the gate connection of the ring-shaped crimped MOSFET array. Figure 8 Figure 9 For a matrix-shaped crimped MOSFET array, as shown in FIG. 3, if all the crimped MOSFETs are controlled by the same gate signal, one design of the gate connection is shown in FIG. 4. If the crimped MOSFETs are controlled by different gate signals, the design idea is the same as that of the gate connection of the ring-shaped crimped MOSFET array.

[0056] The crimping structure of the application applied to the crimped MOSFET array has the following beneficial effects:

[0057] (1) It is suitable for parallel connection of crimped MOSFETs, and has simple and compact structure.

[0058] (2) The elastic structure provides pressure to the contact surface, reduces the contact resistance, uses auxiliary elastic sheets to increase the current-carrying area, thereby increasing the current-carrying capacity of the overall structure.

[0059] (3) The elastic structure provides pressure to the contact surface, reduces the contact surface thermal resistance, and uses a copper-based circuit board to enhance the heat dissipation capacity of the overall structure.

[0060] (4) The elastic structure can limit the upper limit of the pressure on the surface of the MOSFET, thereby increasing the pressure range between the first copper block and the second copper block and making the application range wider.

[0061] The above description is only the preferred embodiment of the application, and should not be construed as limiting the scope of the application. Those skilled in the art can make some modifications and improvements without departing from the concept of the application, which are within the scope of the application.​​

Claims

1. A gate structure applied to a crimping type MOSFET, characterized by: The first copper block, the crimping type MOSFET, the gate connecting piece, the connecting interface receiving the external gate control signal, the second copper block, the elastic structure, the rod-shaped metal in contact with the gate of the crimping type MOSFET, and the insulating medium between the gate connecting piece and the second copper block are included. The crimping type MOSFET is located between the first copper block and the second copper block, and a certain pressure exists between the first copper block and the second copper block; the first copper block includes one or more, and each first copper block is at the same potential as the drain of the crimping type MOSFET; the second copper block includes one or more, and each second copper block is at the same potential as the source of the crimping type MOSFET. The source of the crimping type MOSFET is connected to the protruding part of the second copper block. When the gate connecting piece is a metal structure, the rod-shaped metal is fixed in the groove on the upper surface of the gate connecting piece; when the gate connecting piece is a circuit board, the rod-shaped metal is arranged in the cylindrical structure connected to the positioning hole of the circuit board. When the gate connecting piece is a metal structure, the gate connecting piece is arranged in the groove of the second copper block and is electrically insulated and fixed from the second copper block through the insulating medium; when the gate connecting piece is a circuit board, the insulating medium is the surface of the circuit board. The gate connecting piece and the gate of the crimping type MOSFET are electrically connected through the elastic structure and the rod-shaped metal. The gate connecting piece is connected to the connecting interface, and the connecting interface receives the external gate control signal. One gate connecting piece is used to electrically connect the gates of a plurality of crimping type MOSFETs, and one crimping type MOSFET corresponds to one elastic structure and one rod-shaped metal.

2. The gate structure of claim 1, wherein: The crimping type MOSFET includes a plurality of crimping type MOSFETs and forms a crimping type MOSFET array; and the shape of the gate connecting piece is set according to the arrangement mode of the crimping type MOSFET array. The crimping type MOSFET array adopts a ring shape or a matrix shape; when all the crimping type MOSFETs in the array are controlled by using the same gate signal, one gate connecting piece is used to electrically connect all the crimping type MOSFETs; when the crimping type MOSFETs in the array are controlled by using different gate signals, different gate connecting pieces are used to electrically connect the corresponding crimping type MOSFETs.

3. The gate structure of claim 2, wherein: The first copper block, the crimping type MOSFET die, the gate connecting piece, the connecting interface receiving the external gate control signal, the second copper block, the elastic structure, and the rod-shaped metal in contact with the gate of the crimping type MOSFET die are included.

4. A gate structure applied to a crimp-type MOSFET die, characterized by: The crimping type MOSFET die is located between the first copper block and the second copper block, and a certain pressure exists between the first copper block and the second copper block; the first copper block is connected to the drain of the crimping type MOSFET die, and the second copper block is connected to the source of the crimping type MOSFET die. ​ When the gate connector is a metal structure, the rod-shaped metal is fixed in the groove on the upper surface of the gate connector; when the gate connector is a circuit board, the rod-shaped metal is arranged in the cylindrical structure connected to the positioning hole on the circuit board; The gate connector is electrically connected with the gate of the crimped MOSFET die through the elastic structure and the rod-shaped metal; The gate connector is connected with the connection interface, and the connection interface receives an external gate control signal; One gate connector is used to electrically connect the gates of a plurality of crimped MOSFET dies, wherein one crimped MOSFET die corresponds to one elastic structure and one rod-shaped metal.

5. The gate structure of claim 4, wherein: Wherein, The crimped MOSFET dies include a plurality of and form a crimped MOSFET die array; the shape of the gate connector is set according to the arrangement mode of the crimped MOSFET die array.

6. The gate structure of claim 5, wherein: The crimped MOSFET die array adopts a ring shape or a matrix shape; when all the crimped MSOFET dies in the array are controlled by using the same gate signal, one gate connector is used to electrically connect all the crimped MSOFET dies; when the crimped MSOFET dies in the array are controlled by using different gate signals, different gate connectors are used to electrically connect the corresponding crimped MSOFET dies.

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