High-power semiconductor devices

Abstract

The present application provides a high-power semiconductor device. The high-power semiconductor device includes: a semiconductor chip; the semiconductor chip is located at the top of the high-power semiconductor device; an internal drive board, which is located at the bottom of the high-power semiconductor device; a gate copper block, which is disposed between the chip gate region and the internal drive board; the copper block presses down the MOSFET located on the internal drive board via an elastic conductive component; and the elastic conductive component includes a disc spring for adjusting the pressure applied to the MOSFET. Using this high-power semiconductor device, the copper block presses down the MOSFET located on the internal drive board via the elastic conductive component, thereby ensuring uniform pressure applied to each MOSFET, reducing contact thermal resistance and the internal voltage drop of the high-power semiconductor device. By controlling the compression of the disc spring in the elastic conductive component, the pressure is controlled within a certain range to prevent damage to the MOSFET.

Description

Technical Field

[0001] The present invention relates to the technical field of power semiconductor devices, and in particular to a high-power semiconductor device. Background Art

[0002] With the rapid development of power electronics technology, users are demanding high-power semiconductor devices with fast shutdown and commutation speeds, high shutdown reliability, and excellent heat dissipation. However, the shutdown and commutation speeds, or current-cutting capabilities, are significantly affected by the stray inductance within the commutation circuits within the semiconductor devices. Excessive stray inductance can prevent some cells within the semiconductor device from fully commutating during the shutdown process, leading to shutdown failure.

[0003] By integrating MOSFET inside the tube shell, the area of ​​the commutation loop can be effectively reduced, the stray inductance of the commutation loop can be reduced, and the shutdown capability of the device can be improved. However, integrating a large number of MOSFETs inside the tube shell will increase the difficulty of electrical, mechanical, and heat dissipation design.

[0004] If the copper block is in direct contact with the MOSFETs when soldering them to the internal driver board, the soldering process will result in differences in the contact surfaces between the MOSFETs and the copper block. This structure will make it difficult to balance the pressure between the MOSFETs and achieve balanced contact between the contact interfaces of the MOSFETs and the copper block. On the one hand, press-fit MOSFETs are very sensitive to pressure contact, requiring both uniform pressure and pressure control within a certain range. On the other hand, if the MOSFETs encapsulated inside the tube shell do not make good contact during operation, their contact thermal resistance will be greatly increased. This increase in contact thermal resistance will increase the overall voltage drop of the high-power semiconductor device and can also lead to thermal failure of the MOSFET, affecting the device's shutdown performance and even causing the high-power semiconductor device to fail.

[0005] At the same time, it is also crucial to ensure good electrical connection between high-power semiconductor devices and external circuits, and to prevent high-power semiconductor devices from being subject to electromagnetic interference from external circuits. Summary of the Invention

[0006] In response to the problems in the above-mentioned prior art, the present application proposes a high-power semiconductor device, in which a copper block presses down the MOSFET located on the internal driving board through an elastic conductive component, thereby ensuring that the pressure on each MOSFET is uniform, reducing the contact thermal resistance and the internal voltage drop of the high-power semiconductor device, and by controlling the compression amount of the disc spring in the elastic conductive component, the pressure is controlled within a certain range to prevent damage to the MOSFET.

[0007] The present invention provides a high-power semiconductor device, comprising: a semiconductor chip including an annular chip gate region, a first chip cathode region located within the chip gate region, and a second chip cathode region located outside the chip gate region; the semiconductor chip being located at the top of the high-power semiconductor device; an internal drive board being located at the bottom of the high-power semiconductor device; an inner cathode copper block being disposed between the first chip cathode region and the internal drive board; an outer cathode copper block being disposed between the second chip cathode region and the internal drive board; a gate copper block being disposed between the chip gate region and the internal drive board; the gate copper block, the inner cathode copper block, or the outer cathode copper block pressing down a gate MOSFET, an inner cathode MOSFET, or an outer cathode MOSFET located on the internal drive board via an elastic conductive component; the elastic conductive component including an elastic member for adjusting the pressure applied to the gate MOSFET, the inner cathode MOSFET, or the outer cathode MOSFET; a tube cover being disposed above the semiconductor chip; a tube base being disposed below the internal drive board; and a tube shell being disposed around the tube base and the tube cover. With this high-power semiconductor device, its gate copper block presses down the gate MOSFET located on the internal drive board through the elastic conductive component, thereby ensuring uniform pressure on each gate MOSFET, reducing contact thermal resistance and the internal voltage drop of the high-power semiconductor device. By controlling the compression amount of the elastic part in the elastic conductive component, the pressure is controlled within a certain range to prevent damage to the MOSFET.

[0008] In one embodiment, the elastic conductive component further includes: a bottom cover, the bottom surface of which is in contact with the gate MOSFET, the inner cathode MOSFET, or the outer cathode MOSFET; a top cover, the top surface of which is in contact with the gate copper block, the inner cathode copper block, or the outer cathode copper block; and a screw connecting the bottom cover and the top cover, the screw passing through the top cover and threadedly engaging with the bottom cover; the top cover can move downward along the screw when pressed downward; and the elastic member is a disc spring, which is sleeved on the outside of the top cover and located between the top cover and the bottom cover. Through this embodiment, it is ensured that the pressure applied to the MOSFET is linearly related to the compression of the disc spring, thereby controlling the maximum compression of the disc spring within a certain range, thereby controlling the pressure and keeping the MOSFET within a reasonable pressure value range, thereby greatly reducing the overall voltage drop and contact thermal resistance of the high-power semiconductor device.

[0009] In one embodiment, the bottom surface of the gate copper block, the inner cathode copper block, or the outer cathode copper block, where it contacts the elastic conductive component, is provided with a recessed platform, and the top surface of the top cover engages with the stepped surface of the recessed platform. This embodiment allows the recessed platform to cooperate with the raised structure to better secure the elastic conductive component and better control the downward pressure. The specific value of the downward pressure can be controlled by controlling the height of the recessed platform, thereby adjusting the uniformity of the contact pressure of the pressed MOSFET and the consistency of the contact pressure of the semiconductor chip.

[0010] In one embodiment, the cross-section of the structure where the gate copper block, the inner cathode copper block, or the outer cathode copper block joins the semiconductor chip gradually increases in size from the joining surface downward. This embodiment reduces the area of ​​the joining surface between the copper block and the semiconductor chip, making it easier to control the flatness of the joining surface. This allows for a more concentrated transfer of stress from the MOSFET pressed against the copper block to the semiconductor chip, effectively applying stress to the semiconductor chip while also ensuring good contact.

[0011] In one embodiment, the gate copper block, the inner cathode copper block, or the outer cathode copper block is provided with inner and outer sloped surfaces along the radial inner and outer outer walls of the high-power semiconductor device, and the inner and outer sloped surfaces are symmetrically arranged. In this embodiment, the symmetrical arrangement of the inner and outer sloped surfaces enables ingenious and symmetrical unloading of excess stress and uniform pressure on the MOSFET.

[0012] In one embodiment, the high-power semiconductor device further includes a gate lead terminal. The inner leg of the gate lead terminal is located within the tube case and is electrically conductive with the gate region of the internal driver board. The main body of the gate lead terminal extends through the tube case, and the outer leg of the gate lead terminal is located outside the tube case. This embodiment facilitates electrical connection between the driver within the high-power semiconductor device and external circuits, while also ensuring the airtightness of the ceramic package of the high-power semiconductor device.

[0013] In one embodiment, the gate terminal includes a groove, the opening of which is located inside the main body of the gate terminal and extends radially along the direction of the high-power semiconductor device. In this embodiment, the groove absorbs thermal expansion and contraction of the gate terminal, thereby reducing thermal stress on the gate terminal and ensuring the airtightness of the ceramic package of the high-power semiconductor device.

[0014] In one embodiment, the main body of the gate lead terminal is made of 4J29 alloy, and the inner and outer legs of the gate lead terminal are made of pure copper. This embodiment ensures that the main body of the gate lead terminal has a linear expansion coefficient similar to that of borosilicate glass and has good low-temperature structural stability, which helps ensure the airtightness of the ceramic package of high-power semiconductor devices. The inner and outer legs of the gate lead terminal have excellent electrical conductivity and good ductility, and can withstand multiple bends without breaking, which helps to increase the service life of high-power semiconductor devices.

[0015] In one embodiment, the high-power semiconductor device further includes a gate lead ring that passes through the tube shell and is sintered in the tube shell. Through this embodiment, Vg electrical connection between the driving board inside the high-power semiconductor device and the external circuit can be achieved.

[0016] In one embodiment, the high-power semiconductor device further includes an external interface board, which is connected to the gate lead terminals via screws and an insulating sleeve, and to the gate lead ring via screws and an insulating pressure strip. An SMA connector is welded to the external interface board. In this embodiment, the screw connection improves structural robustness, providing high overall crimping reliability. The pressure strip prevents stress concentration, thereby increasing the service life of the high-power semiconductor device. As a standard connector, the SMA connector enhances the compatibility of high-power semiconductor devices.

[0017] In one embodiment, the SMA connector is connected by a coaxial cable. This embodiment is conducive to improving the anti-electromagnetic interference capability of the high-power semiconductor device, thereby improving the reliability of the high-power semiconductor device.

[0018] In one embodiment, the high-power semiconductor device further includes an anode molybdenum sheet, an inner cathode molybdenum sheet, and an outer cathode molybdenum sheet. The anode molybdenum sheet is located between the semiconductor chip and the tube cover, the inner cathode molybdenum sheet is located between the semiconductor chip and the inner cathode copper block, and the outer cathode molybdenum sheet is located between the semiconductor chip and the outer cathode copper block. This embodiment, due to the high hardness of the molybdenum material, can form a flat anode molybdenum sheet, inner cathode molybdenum sheet, and outer cathode molybdenum sheet, which helps maintain a flat contact surface between the chip and the molybdenum sheet and is not easily bent or deformed.

[0019] In one embodiment, a stepped surface made of red glue is formed along the circumference of the semiconductor chip to limit the fixed position of the anode molybdenum sheet and the outer cathode molybdenum sheet. This embodiment is conducive to preventing the anode molybdenum sheet and the outer cathode molybdenum sheet from being dislodged from their packaging position.

[0020] In one embodiment, the high-power semiconductor device further includes an inner isolation sleeve and an outer isolation sleeve. The inner cathode copper block and the inner cathode molybdenum sheet are located inside the inner isolation sleeve, a gate copper block is located between the inner and outer isolation sleeves, and the outer cathode copper block and the outer cathode molybdenum sheet are located outside the outer isolation sleeve. This embodiment achieves electrical isolation within a limited space.

[0021] In one embodiment, the internal driver board is a double-sided copper-clad substrate. This embodiment provides the internal driver board with a copper layer with good bonding strength, enabling single-sided or double-sided electrical conductivity, high surface flatness, and excellent thermal conductivity, electrical insulation, and machinability. This also increases the effective internal contact heat dissipation area of ​​the high-power semiconductor device, thereby significantly improving the overall heat dissipation capability of the high-power semiconductor device.

[0022] The high-power semiconductor device provided in this application has the following beneficial effects compared to the prior art.

[0023] 1. Utilizing this high-power semiconductor device, its copper block presses down the MOSFET located on the internal driving board through the elastic conductive component, thereby ensuring uniform pressure on each MOSFET, reducing contact thermal resistance and the internal voltage drop of the high-power semiconductor device, and by controlling the compression amount of the disc spring in the elastic conductive component, the pressure is controlled within a certain range to prevent damage to the MOSFET.

[0024] 2. The gate lead terminal is conducive to achieving electrical connection between the internal drive of the high-power semiconductor device and the external circuit, while ensuring the airtightness of the ceramic package of the high-power semiconductor device.

[0025] 3. A groove is provided on the gate lead terminal, which is used to absorb thermal expansion and contraction of the gate lead terminal to reduce thermal stress of the gate lead terminal and ensure the airtightness of the ceramic package of the high-power semiconductor device.

[0026] 4. An SMA connector is welded on the external interface board. The SMA connector uses a coaxial cable connection method, which is beneficial to improving the anti-electromagnetic interference capability of high-power semiconductor devices, thereby improving the reliability of high-power semiconductor devices.

[0027] 5. The high-power semiconductor device further comprises an inner isolation sleeve and an outer isolation sleeve, thereby achieving electrical isolation in a limited space.

[0028] The above technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, in which:

[0030] Figure 1 shows an exploded schematic diagram of a high-power semiconductor device according to an embodiment of the present invention;

[0031] Figure 2 shows a cross-sectional schematic diagram of a high-power semiconductor device according to an embodiment of the present invention;

[0032] Figure 3 It shows a schematic structural diagram of an internal driving plate according to one embodiment of the present invention;

[0033] Figure 4 shows a schematic structural diagram of an elastic conductive component according to an embodiment of the present invention;

[0034] Figure 5 shows a cross-sectional schematic diagram of a gate lead terminal according to an embodiment of the present invention;

[0035] Figure 6 shows a schematic structural diagram of an external interface board according to an embodiment of the present invention;

[0036] Figure 7 A schematic structural diagram of a gate copper block according to an embodiment of the present invention is shown.

[0037] Reference numerals list:

[0038] 1-External interface board; 2-Gate lead terminal; 3-Tube shell; 4-Tube cover; 5-External cathode copper block; 6-External isolation sleeve; 7-Gate copper block; 8-Inner isolation sleeve; 9-Anode molybdenum sheet; 10-Inner cathode molybdenum sheet; 11-Inner cathode copper block; 12-External cathode molybdenum sheet; 13-Semiconductor chip; 14-Elastic conductive component; 15-MOSFET; 16-Internal driver board; 17-Tube base; 18-Bottom cover; 19-Top cover; 20-Screw; 21-Disc spring; 22-Protrusion structure; 23-Main body of gate lead terminal; 24-Groove; 25-SMA connector; 26-Sunk platform; 27-Inner slope; 28-Outer slope

[0039] In the drawings, like reference numerals are used for like parts, but the drawings are not necessarily true to scale. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings.

[0041] like Figure 1 and Figure 2As shown, this embodiment provides a high-power semiconductor device, which includes: a semiconductor chip 13, which includes an annular chip gate region, a first chip cathode region located in the chip gate region, and a second chip cathode region located outside the chip gate region; the semiconductor chip 13 is located at the top of the high-power semiconductor device; an internal driving board 16, which is located at the bottom of the high-power semiconductor device; an inner cathode copper block 11, which is arranged between the first chip cathode region and the internal driving board 16; an outer cathode copper block 5, which is arranged between the second chip cathode region and the internal driving board 16; a gate copper block 7, It is arranged between the chip gate area and the internal driving board 16; the gate copper block 7, the internal cathode copper block 11 or the external cathode copper block 5 presses down the gate MOSFET, the internal cathode MOSFET or the external cathode MOSFET located on the internal driving board 16 through the elastic conductive component 14; the elastic conductive component 14 includes an elastic part for adjusting the pressure exerted on the gate MOSFET, the internal cathode MOSFET or the external cathode MOSFET; the tube cover 4 is arranged above the semiconductor chip 13; the tube base 17 is arranged below the internal driving board 16; and the tube shell 3 is arranged around the tube base 17 and the tube cover 4.

[0042] The tube shell 3, the tube base 17 and the tube cover 4 are the packaging shell of the high-power semiconductor device.

[0043] The semiconductor chip 13 may be a gate commutated thyristor (GCT) semiconductor chip 13, which includes an annular chip gate region, a circular first chip cathode region located within the chip gate region, and an annular second chip cathode region located outside the chip gate region.

[0044] The copper block refers to the gate copper block 7, the inner cathode copper block 11 or the outer cathode copper block 5.

[0045] The MOSFET 15 includes a gate MOSFET, an inner cathode MOSFET, and an outer cathode MOSFET.

[0046] Preferably, if Figure 3 As shown, a plurality of MOSFETs 15 are provided on the internal driver board 16, divided into four circles. The diameter of each circle of MOSFETs 15 increases, and the number of MOSFETs 15 increases. The first circle of MOSFETs 15 is located at the innermost part. It and the second circle of MOSFETs 15 are both inner cathode MOSFETs. The third circle of MOSFETs 15 are gate MOSFETs. The fourth circle of MOSFETs 15 are outer cathode MOSFETs.

[0047] The MOSFET 15 on the internal driving board 16 has a compact layout, high spatial integration, and a symmetrical overall structure, which not only realizes the electrical function but also can well ensure the pressure uniformity of the high-power semiconductor device.

[0048] The chip gate region is electrically connected to the gate region of the internal driving board 16 through the gate copper block 7 and the gate MOSFET.

[0049] In the prior art, when each MOSFET 15 is welded to the internal driver board 16, the copper block is allowed to directly contact the MOSFET 15. Due to the difference in the contact surface between each MOSFET 15 and the copper block caused by the welding process, this structure will make it difficult to balance the pressure between each MOSFET 15, and it is difficult to achieve balanced contact between the contact interfaces of each MOSFET 15 and the copper block. On the one hand, the press-fit MOSFET is very sensitive to pressure contact, which requires both uniform pressure and pressure control within a certain range. On the other hand, if the MOSFET 15 encapsulated in the tube shell 3 does not make good contact during operation, its contact thermal resistance will be greatly increased. The increase in contact thermal resistance will increase the overall voltage drop of the high-power semiconductor device, and will also cause thermal failure of the MOSFET 15, affecting the shutdown performance of the device, and even causing the failure of the high-power semiconductor device.

[0050] In order to solve the above technical problems, this embodiment adopts an elastic conductive component 14 and uses the elastic conductive component 14 to directly apply pressure to the MOSFET 15. The elastic conductive component 14 includes an elastic member for adjusting the pressure applied to the MOSFET 15.

[0051] The pressure on MOSFET 15 is linearly related to the compression of the elastic member. The maximum compression of the elastic member can be controlled within a certain range, thereby controlling the pressure, keeping MOSFET 15 within a reasonable pressure range, and significantly reducing the overall voltage drop and contact thermal resistance of the high-power semiconductor device.

[0052] The copper block of the high-power semiconductor device presses down the MOSFET 15 located on the internal driving board 16 through the elastic conductive component 14, thereby ensuring that the pressure on each MOSFET is uniform, reducing the contact thermal resistance and the internal voltage drop of the high-power semiconductor device, and by controlling the compression amount of the elastic part in the elastic conductive component 14, the pressure is controlled within a certain range to prevent damage to the MOSFET.

[0053] In this embodiment, the base 17 and the cover 4 have large areas, which is beneficial to ensuring the double-sided heat dissipation effect of the high-power semiconductor device, greatly reducing the contact thermal resistance and improving the heat dissipation efficiency.

[0054] At the same time, since many MOSFETs 15 are integrated inside the package shell, the commutation loop inductance is greatly reduced. In addition, the maximum commutation voltage is the breakdown voltage of the MOSFET 15 under the cathode copper block, which improves the gate cathode reverse breakdown withstand voltage, thereby greatly improving the commutation speed, reducing the commutation differences between different cells, and improving the overall shutdown capability of the chip.

[0055] In addition, the entire internal cavity of the high-power semiconductor device is filled with nitrogen or an inert gas that is stable and not easily decomposed, wherein the inert gas can be helium.

[0056] Utilizing this high-power semiconductor device, its copper block presses down the MOSFET 15 located on the internal driving board 16 through the elastic conductive component 14, thereby ensuring uniform pressure on each MOSFET 15, reducing the contact thermal resistance and the internal voltage drop of the high-power semiconductor device, and by controlling the compression amount of the elastic part in the elastic conductive component 14, the pressure is controlled within a certain range to prevent damage to the MOSFET.

[0057] In one embodiment, Figure 4 As shown, the elastic conductive component 14 also includes: a bottom cover 18, whose bottom surface is in contact with the MOSFET; a top cover 19, whose top surface is in contact with the copper block 7; and a screw 20, which connects the bottom cover 18 and the top cover 19, and the screw 20 passes through the top cover 19 and is threadedly engaged with the bottom cover 18; the top cover 19 can move downward along the screw 20 when pressed downward; the elastic member is a disc spring 21, which is sleeved on the outside of the top cover 19 and located between the top cover 19 and the bottom cover 18.

[0058] Through this implementation, it is ensured that the pressure on MOSFET15 is linearly related to the compression of the disc spring 21, thereby controlling the maximum compression of the disc spring 21 within a certain range to control the pressure size, so that the MOSFET is always within a reasonable pressure value range, greatly reducing the overall voltage drop and contact thermal resistance of the high-power semiconductor device.

[0059] In one embodiment, Figure 7 As shown, a sink 26 is provided on the bottom surface of the copper block that contacts the elastic conductive component 14 , and the top surface of the top cover 19 is engaged with the step surface of the sink 26 .

[0060] The top cover 19 of the elastic conductive component 14 is provided with a raised structure 22, the outer sidewall of which fits in contact with the vertical stepped surface of the sunken platform 26. The lateral stepped surface of the sunken platform 26 fits in contact with the top surface of the top cover 19, thereby applying downward pressure to the disc spring 21 through the copper block.

[0061] At the same time, the deformation of the disc spring 21 can be controlled by controlling the height of the sinking platform 26.

[0062] Through this embodiment, the sink 26 cooperates with the protruding structure 22 to better fix the elastic conductive component 14 to better control the downward force. The specific value of the downward force can be controlled by controlling the height of the sink 26, thereby adjusting the uniformity of the contact pressure of the crimped MOSFET and the consistency of the contact pressure of the semiconductor chip 13.

[0063] In one embodiment, Figure 7 As shown, the cross section of the structure where the copper block is bonded to the semiconductor chip 13 gradually increases from the bonding surface downward.

[0064] Through this embodiment, the joint surface area between the copper block and the semiconductor chip 13 is smaller, and the flatness of the joint surface is easier to control, so that the stress on the MOSFET pressed by the copper block 7 is transferred to the semiconductor chip 13 in a relatively concentrated manner, which not only makes the semiconductor chip 13 bear the force well, but also ensures good contact.

[0065] In one embodiment, Figure 7 As shown, an inner slope surface 27 and an outer slope surface 28 are provided on the radial inner side wall and outer side wall of the copper block along the high-power semiconductor device, and the inner slope surface 27 and the outer slope surface 28 are symmetrically arranged.

[0066] Through this embodiment, the symmetrical arrangement of the inner slope surface 27 and the outer slope surface 28 can cleverly and symmetrically unload the excess stress and make the pressure on the MOSFET uniform.

[0067] In one embodiment, the high-power semiconductor device further includes a gate lead terminal 2, such as Figure 2 As shown, the inner leg of the gate terminal 2 is located inside the tube case 3 and is conductive with the gate region of the internal driving board 16 , the main body 23 of the gate terminal passes through the tube case 3 , and the outer leg of the gate terminal 2 is located outside the tube case 3 .

[0068] Alternatively, as Figure 1 As shown, the three gate lead terminals 2 from left to right are connected to Qe, Qg and Vk respectively.

[0069] Through this embodiment, the gate lead terminal 2 is conducive to achieving electrical connection between the internal drive of the high-power semiconductor device and the external circuit, while ensuring the airtightness of the ceramic package of the high-power semiconductor device.

[0070] In one embodiment, Figure 5 As shown, a groove 24 is formed on the gate lead terminal 2. The opening of the groove 24 is located inside the main body 23 of the gate lead terminal. The groove 24 extends along the radial direction of the high-power semiconductor device.

[0071] Through this embodiment, the groove 24 is used to absorb the thermal expansion and contraction of the gate lead terminal 2, so as to reduce the thermal stress of the gate lead terminal 2 and ensure the airtightness of the ceramic package of the high-power semiconductor device.

[0072] In one embodiment, the main body 23 of the gate lead terminal is made of 4J29 alloy material, and the inner leg of the gate lead terminal 2 and the outer leg of the gate lead terminal 2 are made of pure copper material.

[0073] Through this embodiment, the main body 23 of the gate lead terminal has a linear expansion coefficient close to that of borosilicate glass, and has good low-temperature structural stability, and is conducive to ensuring the airtightness of the ceramic packaging shell of the high-power semiconductor device; the inner and outer legs of the gate lead terminal 2 have excellent electrical conductivity and good ductility, and can be bent multiple times without breaking, which is conducive to improving the service life of the high-power semiconductor device.

[0074] In one embodiment, the high-power semiconductor device further includes a gate lead-out ring, which passes through the tube shell 3 and is sintered in the tube shell 3 .

[0075] Through this embodiment, it is possible to achieve electrical connection of Vg between the driving board inside the high-power semiconductor device and the external circuit.

[0076] In one embodiment, Figure 1 and Figure 6 As shown, the high-power semiconductor device also includes an external interface board 1, which is connected to the gate lead terminal 2 via screws 20 and an insulating sleeve, and is connected to the gate lead ring via screws 20 and an insulating strip; an SMA connector 25 is welded on the external interface board 1.

[0077] Alternatively, as Figure 1 As shown, four SMA connectors 25 from left to right are connected to Qe, Qg, Vg and Vk respectively.

[0078] Through this embodiment, the screw 20 connection is conducive to improving the firmness of the structure, the overall crimping reliability is high, the pressure strip can avoid stress concentration, which is conducive to improving the service life of high-power semiconductor devices. The SMA connector 25 as a standard connector can improve the compatibility of high-power semiconductor devices.

[0079] In one embodiment, the SMA connector 25 is connected by a coaxial cable.

[0080] This implementation helps to improve the anti-electromagnetic interference capability of the high-power semiconductor device, thereby improving the reliability of the high-power semiconductor device.

[0081] In one embodiment, the high-power semiconductor device further includes an anode molybdenum sheet 9, an inner cathode molybdenum sheet 10, and an outer cathode molybdenum sheet 12. The anode molybdenum sheet 9 is located between the semiconductor chip 13 and the tube cover 4, the inner cathode molybdenum sheet 10 is located between the semiconductor chip 13 and the inner cathode copper block 11, and the outer cathode molybdenum sheet 12 is located between the semiconductor chip 13 and the outer cathode copper block 5.

[0082] Through this embodiment, due to the high hardness of the molybdenum material, a flat anode molybdenum sheet 9, an inner cathode molybdenum sheet 10 and an outer cathode molybdenum sheet 12 can be formed, which is conducive to keeping the contact surface between the chip and the molybdenum sheet flat and not easy to bend and deform.

[0083] In one embodiment, a step surface made of red glue is formed along the circumference of the semiconductor chip 13 to limit the fixed positions of the anode molybdenum sheet 9 and the outer cathode molybdenum sheet 12.

[0084] The vertical red glue step surface on the top surface of the semiconductor chip 13 fits with the edge of the anode molybdenum sheet 9, and the vertical red glue step surface on the bottom surface of the semiconductor chip 13 fits with the edge of the outer cathode molybdenum sheet 12, thereby preventing the anode molybdenum sheet 9 and the outer cathode molybdenum sheet 12 from being separated from their packaging positions.

[0085] This embodiment can help prevent the anode molybdenum sheet 9 and the outer cathode molybdenum sheet 12 from being separated from their packaging positions.

[0086] In one embodiment, the high-power semiconductor device further includes an inner isolation sleeve 8 and an outer isolation sleeve 6, the inner side of the inner isolation sleeve 8 is an inner cathode copper block 11 and an inner cathode molybdenum sheet 10, the gate copper block 7 is between the inner isolation sleeve 8 and the outer isolation sleeve 6, and the outer side of the outer isolation sleeve 6 is an outer cathode copper block 5 and an outer cathode molybdenum sheet 12.

[0087] In the radial direction, the inner isolation sleeve 8 and the outer isolation sleeve 6 are symmetrically arranged relative to the vertical midline of the cross section of the gate copper block 7 , thereby ensuring a good pressure uniformity of the semiconductor chip 13 .

[0088] With this embodiment, electrical isolation is achieved in a limited space.

[0089] In one embodiment, the internal driving board 16 is a double-sided copper clad substrate.

[0090] The internal drive boards in the prior art are mostly epoxy boards with poor thermal conductivity.

[0091] Through this implementation, the copper layer of the internal driving board 16 has good bonding strength, can achieve single-sided or double-sided conductivity, and has high surface flatness, good thermal conductivity, electrical insulation and machinability. At the same time, it increases the internal effective contact heat dissipation area of ​​the high-power semiconductor device, thereby greatly improving the overall heat dissipation capacity of the high-power semiconductor device.

[0092] Example 1

[0093] like Figure 1 and Figure 2 As shown, this embodiment provides a high-power semiconductor device, which includes: a semiconductor chip 13, which includes an annular chip gate region, a first chip cathode region located in the chip gate region, and a second chip cathode region located outside the chip gate region; the semiconductor chip 13 is located at the top of the high-power semiconductor device; an internal driving board 16 is located at the bottom of the high-power semiconductor device; an internal cathode copper block 11 is arranged between the first chip cathode region and the internal driving board 16; an external cathode copper block 5 is arranged between the second chip cathode region and the internal driving board 16; a gate copper block 7, It is arranged between the chip gate area and the internal driving board 16; the gate copper block 7, the internal cathode copper block 11 or the external cathode copper block 5 presses down the gate MOSFET, the internal cathode MOSFET or the external cathode MOSFET located on the internal driving board 16 through the elastic conductive component 14; the elastic conductive component 14 includes an elastic part for adjusting the pressure exerted on the gate MOSFET, the internal cathode MOSFET or the external cathode MOSFET; the tube cover 4 is arranged above the semiconductor chip 13; the tube base 17 is arranged below the internal driving board 16; and the tube shell 3 is arranged around the tube base 17 and the tube cover 4.

[0094] The tube shell 3, the tube base 17 and the tube cover 4 are the packaging shell of the high-power semiconductor device.

[0095] The semiconductor chip 13 may be a gate commutated thyristor (GCT) semiconductor chip 13, which includes an annular chip gate region, a circular first chip cathode region located within the chip gate region, and an annular second chip cathode region located outside the chip gate region.

[0096] The copper block refers to the gate copper block 7, the inner cathode copper block 11 or the outer cathode copper block 5.

[0097] The MOSFET 15 includes a gate MOSFET, an inner cathode MOSFET, and an outer cathode MOSFET.

[0098] Preferably, if Figure 3 As shown, a plurality of MOSFETs 15 are provided on the internal driver board 16, divided into four circles. The diameter of each circle of MOSFETs 15 increases, and the number of MOSFETs 15 increases. The first circle of MOSFETs 15 is located at the innermost part. It and the second circle of MOSFETs 15 are both inner cathode MOSFETs. The third circle of MOSFETs 15 are gate MOSFETs. The fourth circle of MOSFETs 15 are outer cathode MOSFETs.

[0099] The MOSFET 15 on the internal driving board 16 has a compact layout, high spatial integration, and a symmetrical overall structure, which not only realizes the electrical function but also can well ensure the pressure uniformity of the high-power semiconductor device.

[0100] The chip gate region is electrically connected to the gate region of the internal driving board 16 through the gate copper block 7 and the gate MOSFET.

[0101] In the prior art, when each MOSFET is welded to the internal driver board 16, the copper block is allowed to directly contact the MOSFET 15. Due to the difference in the contact surface between each MOSFET 15 and the copper block caused by the welding process, this structure will make it difficult to balance the pressure between each MOSFET 15, and it is difficult to achieve balanced contact between the contact interfaces of each MOSFET 15 and the copper block. On the one hand, the crimped MOSFET 15 is very sensitive to pressure contact, which requires both uniform pressure and pressure control within a certain range. On the other hand, if the MOSFET 15 encapsulated in the tube shell 3 does not make good contact during operation, its contact thermal resistance will be greatly increased. The increase in contact thermal resistance will increase the overall voltage drop of the high-power semiconductor device, and will also cause thermal failure of the MOSFET 15, affecting the shutdown performance of the device, and even causing the failure of the high-power semiconductor device.

[0102] In order to solve the above technical problems, this embodiment adopts an elastic conductive component 14 and uses the elastic conductive component 14 to directly apply pressure to the MOSFET 15. The elastic conductive component 14 includes a disc spring 21 for adjusting the pressure applied to the MOSFET 15.

[0103] The pressure on MOSFET 15 is linearly related to the compression of disc spring 21. The maximum compression of disc spring 21 can be controlled within a certain range, thereby controlling the pressure, keeping MOSFET 15 within a reasonable pressure range, and significantly reducing the overall voltage drop and contact thermal resistance of the high-power semiconductor device.

[0104] The copper block of the high-power semiconductor device presses down the MOSFET15 located on the internal driving board 16 through the elastic conductive component 14, thereby ensuring that the pressure on each MOSFET is uniform, reducing the contact thermal resistance and the internal voltage drop of the high-power semiconductor device, and by controlling the compression amount of the disc spring 21 in the elastic conductive component 14, the pressure is controlled within a certain range.

[0105] In this embodiment, the base 17 and the cover 4 have large areas, which is beneficial to ensuring the double-sided heat dissipation effect of the high-power semiconductor device, greatly reducing the contact thermal resistance and improving the heat dissipation efficiency.

[0106] At the same time, since many MOSFETs 15 are integrated inside the package shell, the commutation loop inductance is greatly reduced. In addition, the maximum commutation voltage is the breakdown voltage of the MOSFET 15 under the cathode copper block, which improves the gate cathode reverse breakdown withstand voltage, thereby greatly improving the commutation speed, reducing the commutation differences between different cells, and improving the overall shutdown capability of the chip.

[0107] Utilizing this high-power semiconductor device, its copper block presses down the MOSFET 15 located on the internal driving board 16 through the elastic conductive component 14, thereby ensuring that the pressure on each MOSFET 15 is uniform, reducing the contact thermal resistance and the internal voltage drop of the high-power semiconductor device, and by controlling the compression amount of the disc spring 21 in the elastic conductive component 14, the pressure is controlled within a certain range.

[0108] Example 2

[0109] like Figure 4 As shown, the elastic conductive component 14 also includes: a bottom cover 18, whose bottom surface is in contact with the MOSFET 15; a top cover 19, whose top surface is in contact with the copper block; and a screw 20, which connects the bottom cover 18 and the top cover 19, and the screw 20 passes through the top cover 19 and is threadedly engaged with the bottom cover 18; the top cover 19 can move downward along the screw 20 when pressed down; a disc spring 21 is sleeved on the outside of the top cover 19 and is located between the top cover 19 and the bottom cover 18.

[0110] The above structure ensures that the pressure on MOSFET15 is linearly related to the compression of the disc spring 21, thereby controlling the maximum compression of the disc spring 21 within a certain range to control the pressure so that MOSFET15 is always within a reasonable pressure value range, greatly reducing the overall voltage drop and contact thermal resistance of the high-power semiconductor device.

[0111] A sink 26 is provided on the bottom surface of the copper block that contacts the elastic conductive component 14 , and the top surface of the top cover 19 engages with the stepped surface of the sink 26 .

[0112] The top cover 19 of the elastic conductive component 14 is provided with a raised structure 22, the outer sidewall of which fits in contact with the vertical stepped surface of the sunken platform 26. The lateral stepped surface of the sunken platform 26 fits in contact with the top surface of the top cover 19, thereby applying downward pressure to the disc spring 21 through the copper block.

[0113] At the same time, the deformation of the disc spring 21 can be controlled by controlling the height of the sinking platform 26.

[0114] The sink 26 cooperates with the protruding structure 22 to better fix the elastic conductive component 14 to better control the downward pressure. The specific value of the downward pressure can be controlled by controlling the height of the sink 26, thereby adjusting the uniformity of the contact pressure of the crimped MOSFET15 and the consistency of the contact pressure of the semiconductor chip 13.

[0115] The cross-section of the structure where the copper block is joined to the semiconductor chip 13 gradually increases from the joint surface downward, so that the joint surface area between the copper block and the semiconductor chip 13 is smaller, and it is easier to control the flatness of the joint surface, so that the stress on the MOSFET 15 pressed by the copper block is transferred to the semiconductor chip 13 in a relatively concentrated manner, which not only makes the semiconductor chip 13 bear good force, but also ensures good contact.

[0116] The copper block is provided with an inner slope surface 27 and an outer slope surface 28 on the radial inner and outer walls of the high-power semiconductor device. The inner slope surface 27 and the outer slope surface 28 are symmetrically arranged. Thus, the symmetrical arrangement of the inner slope surface 27 and the outer slope surface 28 can cleverly and symmetrically unload the excess stress and make the pressure of the gate MOSFET uniform.

[0117] Example 3

[0118] The high-power semiconductor device also includes a gate lead terminal 2, such as Figure 2 As shown, the inner leg of the gate terminal 2 is located inside the tube case 3 and is conductive with the gate region of the internal driving board 16 , the main body 23 of the gate terminal passes through the tube case 3 , and the outer leg of the gate terminal 2 is located outside the tube case 3 .

[0119] Alternatively, as Figure 1 As shown, the three gate lead terminals 2 from left to right are connected to Qe, Qg and Vk respectively.

[0120] The gate lead terminal 2 is conducive to achieving electrical connection between the internal drive of the high-power semiconductor device and the external circuit, and can also ensure the airtightness of the ceramic package of the high-power semiconductor device.

[0121] like Figure 5 As shown, a groove 24 is provided on the gate lead terminal 2. The opening of the groove 24 is located on the inner side of the main body 23 of the gate lead terminal. The groove 24 extends along the radial direction of the high-power semiconductor device. The groove 24 is used to absorb the thermal expansion and contraction of the gate lead terminal 2 to reduce the thermal stress of the gate lead terminal 2 and ensure the airtightness of the ceramic package shell of the high-power semiconductor device.

[0122] The main body 23 of the gate lead terminal is made of 4J29 alloy material, and the inner leg of the gate lead terminal 2 and the outer leg of the gate lead terminal 2 are made of pure copper material, so that the main body 23 of the gate lead terminal has a linear expansion coefficient similar to that of borosilicate glass, and has good low-temperature structural stability, and is conducive to ensuring the airtightness of the ceramic packaging shell of the high-power semiconductor device; the inner leg and the outer leg of the gate lead terminal 2 have excellent electrical conductivity and good ductility, and can be bent multiple times without breaking, which is conducive to improving the service life of the high-power semiconductor device.

[0123] The high-power semiconductor device further includes a gate lead-out ring which penetrates the tube shell 3 and is sintered in the tube shell 3 , thereby enabling Vg electrical connection between the driving board inside the high-power semiconductor device and the external circuit.

[0124] Example 4

[0125] The high-power semiconductor device also includes an external interface board 1, the external interface board 1 is connected to the gate lead terminal 2 through screws 20 and an insulating sleeve, and the external interface board 1 is connected to the gate lead ring through screws 20 and an insulating strip; Figure 1 and Figure 6 As shown, an SMA connector 25 is welded on the external interface board 1 .

[0126] Alternatively, as Figure 1 As shown, four SMA connectors 25 from left to right are connected to Qe, Qg, Vg and Vk respectively.

[0127] The screw 20 connection is conducive to improving the firmness of the structure, the overall crimping reliability is high, the pressure strip can avoid stress concentration, which is conducive to improving the service life of high-power semiconductor devices. The SMA connector 25 as a standard connector can improve the compatibility of high-power semiconductor devices.

[0128] In this embodiment, the SMA connector 25 adopts a coaxial cable connection method, which is beneficial to improving the anti-electromagnetic interference capability of the high-power semiconductor device, thereby improving the reliability of the high-power semiconductor device.

[0129] In the description of the present invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "back", "inside", "outside", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0130] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be employed in conjunction with other described embodiments.

Claims

1. A high-power semiconductor device, characterized in that: include: A semiconductor chip comprising an annular chip gate region, a first chip cathode region located within the chip gate region, and a second chip cathode region located outside the chip gate region; the semiconductor chip is located on top of a high-power semiconductor device; an internal driver board, which is located at the bottom of the high-power semiconductor device; an inner cathode copper block, which is disposed between the cathode region of the first chip and the inner driving board; an outer cathode copper block, which is disposed between the cathode region of the second chip and the internal driving board; A gate copper block, which is arranged between the chip gate region and the internal driving board; The gate copper block, the inner cathode copper block or the outer cathode copper block presses down the gate MOSFET, the inner cathode MOSFET or the outer cathode MOSFET located on the internal driving board through an elastic conductive component; the elastic conductive component includes an elastic member for adjusting the pressure applied to the gate MOSFET, the inner cathode MOSFET or the outer cathode MOSFET; a tube cover, which is arranged above the semiconductor chip; a tube seat, which is arranged below the internal driving plate; as well as, The tube shell is arranged around the tube base and the tube cover.

2. The high-power semiconductor device according to claim 1, characterized in that: The elastic conductive component further includes: a bottom cover, the bottom surface of which is in contact with the gate MOSFET, the inner cathode MOSFET or the outer cathode MOSFET; a top cover, the top surface of which is in contact with the gate copper block, the inner cathode copper block or the outer cathode copper block; and a screw connecting the bottom cover and the top cover, wherein the screw passes through the top cover and engages with the bottom cover in threaded engagement; The top cover can move downward along the screw when pressed downward; the elastic member is a disc spring, which is sleeved on the outside of the top cover and located between the top cover and the bottom cover.

3. The high-power semiconductor device according to claim 2, characterized in that: The bottom surface of the gate copper block, the inner cathode copper block or the outer cathode copper block in contact with the elastic conductive component is provided with a sinking platform, and the top surface of the top cover is engaged with the step surface of the sinking platform.

4. The high-power semiconductor device according to claim 1, characterized in that: The cross-section of the structure where the gate copper block, the inner cathode copper block or the outer cathode copper block is bonded to the semiconductor chip gradually increases from the bonding surface downwards.

5. The high-power semiconductor device according to claim 1, characterized in that: The gate copper block, the inner cathode copper block or the outer cathode copper block is provided with inner and outer slope surfaces on the radial inner and outer side walls of the high-power semiconductor device, and the inner and outer slope surfaces are symmetrically arranged.

6. The high-power semiconductor device according to claim 1, characterized in that: It also includes a gate lead-out terminal, the inner leg of the gate lead-out terminal is located inside the tube shell and is connected to the gate area of ​​the internal drive board, the main body of the gate lead-out terminal passes through the tube shell, and the outer leg of the gate lead-out terminal is located outside the tube shell.

7. The high-power semiconductor device according to claim 6, characterized in that: A groove is provided on the gate lead terminal, an opening of the groove is located on the inner side of the main body of the gate lead terminal, and the groove extends along the radial direction of the high-power semiconductor device.

8. The high-power semiconductor device according to claim 6, characterized in that: The main body of the gate lead terminal is made of 4J29 alloy material, and the inner leg of the gate lead terminal and the outer leg of the gate lead terminal are made of pure copper material.

9. The high-power semiconductor device according to claim 6, characterized in that: It also includes a gate lead-out ring, which passes through the tube shell and is sintered in the tube shell.

10. The high-power semiconductor device according to claim 9, characterized in that: It also includes an external interface board, which is connected to the gate lead terminal through screws and insulating sleeves, and is connected to the gate lead ring through screws and insulating strips; an SMA connector is welded on the external interface board.

11. The high-power semiconductor device according to claim 10, characterized in that: The SMA connector adopts a coaxial cable connection method.

12. The high-power semiconductor device according to claim 1, characterized in that: It also includes an anode molybdenum sheet, an inner cathode molybdenum sheet and an outer cathode molybdenum sheet. The anode molybdenum sheet is located between the semiconductor chip and the tube cover, the inner cathode molybdenum sheet is located between the semiconductor chip and the inner cathode copper block, and the outer cathode molybdenum sheet is located between the semiconductor chip and the outer cathode copper block.

13. The high-power semiconductor device according to claim 12, characterized in that: A step surface made of red glue is formed along the circumferential periphery of the semiconductor chip to limit the fixed positions of the anode molybdenum sheet and the outer cathode molybdenum sheet.

14. The high-power semiconductor device according to claim 12, characterized in that: It also includes an inner isolation sleeve and an outer isolation sleeve, the inner side of the inner isolation sleeve is the inner cathode copper block and the inner cathode molybdenum sheet, the gate copper block is between the inner isolation sleeve and the outer isolation sleeve, and the outer side of the outer isolation sleeve is the outer cathode copper block and the outer cathode molybdenum sheet.

15. The high-power semiconductor device according to claim 1, characterized in that: The internal driving board is a double-sided copper-clad substrate.

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