Integrated composite lead structure, tube shell and manufacturing method thereof, power device

Abstract

An integrally formed composite lead structure, a tube shell and a manufacturing method thereof, and a power device. The integrally formed composite lead structure includes a gate lead portion and a cathode lead portion, and an insulating layer that electrically insulates the gate lead portion and the cathode lead portion from each other, wherein the gate lead portion, the insulating layer and the cathode lead portion are integrally formed to form a "sandwich" structure. The present invention adopts a preformed "sandwich" structure to achieve the design of a low-inductance tube shell and minimize the integrated inductance of the device drive circuit; at the same time, high-temperature resistant insulating glue is filled at the gate and cathode welding positions to improve the insulation and sealing performance of the tube shell, and the gate lead spokes are designed with an insulating coating and an insulating sleeve to further reduce the mutual inductance between the current paths and improve the reliability of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor packaging, and in particular to an integrally formed composite lead structure, a tube shell and a manufacturing method thereof, in particular to a packaging tube shell of a high-power semiconductor device and a manufacturing method thereof, and a power device using the same. Background Art

[0002] Integrated Gate-Commutated Thyristor (IGCT) is a new type of power electronic device that appeared in the late 1990s. It combines the advantages of IGBT and GTO. Its capacity is comparable to that of GTO, but its switching speed is 10 times faster than that of GTO, and it does not need a large and complex snubber circuit like GTO. At present, IGCT is competing fiercely with IGBT and other new devices, and plays an increasingly important role in high-power control and switching occasions such as ultra-high voltage transmission.

[0003] The IGCT device is mainly composed of a GCT (Gate-Commutated Thyristor) element and a driving circuit board connected to the lead-out electrode. The GCT element is the core component of the IGCT device and is very important. Existing IGCT devices are usually packaged using a rigid press-fit structure, such as Figure 1 As shown, the GCT element is mainly composed of a semiconductor switch chip (wafer 14) and a package tube shell, and the package tube shell includes a tube seat 20, a gate assembly, a cathode sheet 15 made of molybdenum, an anode sheet 13 made of molybdenum, an insulating sleeve 12, a tube shell cover 11, etc., wherein the gate assembly is mainly composed of gaskets 31, 31', elastic sheets 32, 32' as springs, gate lead spokes 19, a gate insulating seat 18, a gate gasket 17 and a gate ring 16. The electrical connection of all components is completely achieved by pressure contact.

[0004] like Figure 2A and 2B As shown, the lead-out method of the gate lead-out ring 23 of the existing package tube shell is to lead out from the middle of the tube shell ceramic ring 1 (ceramic foam ring). The ceramic ring 1 of the tube shell needs to be divided into two parts, and then the upper and lower ceramic rings 1 are connected to the gate lead-out ring 23 by welding; finally, the upper and lower electrode copper metal umbrella skirts are welded to the upper and lower surfaces of the ceramic ring 1. Considering the yield rate of the ceramic ring 1, the thickness of the lower ceramic ring is generally ≥5mm, which limits the further reduction of the driving circuit area; at the same time, the middle lead-out structure of the gate lead-out ring 23 causes the minimum insulation distance of the tube seat 20 to be the distance between the edge of the upper electrode copper metal umbrella skirt and the edge of the gate lead-out ring 23. Therefore, in order to ensure the insulation distance of the device, the overall thickness of the tube shell is increased. Therefore, the shortcomings of the existing crimped package tube shell structure are mainly:

[0005] (1) The device gate is led out from the inside of the ceramic ring 1, and the parasitic inductance of the drive circuit is large;

[0006] (2) The ceramic ring 1 consists of two parts, upper and lower, which requires secondary welding, is difficult to process, and has a low yield rate;

[0007] (3) The gate lead ring 23 is led out from the ceramic ring 1, which reduces the insulation distance of the tube shell and increases the manufacturing cost of the tube shell.

[0008] In addition, as the voltage level and high current shutdown capability of devices continue to increase, the voltage overshoot caused by device parasitic parameters and device failure caused by uneven current distribution are becoming increasingly serious. Therefore, it is urgent to optimize the packaging structure, reduce the difficulty of assembly processing, and optimize the packaging parasitic parameters to improve the device yield. Summary of the invention

[0009] In view of this, the main purpose of the present invention is to provide an integrally formed composite lead structure, a tube shell and a manufacturing method thereof, and a power device, in order to at least partially solve the above technical problems.

[0010] In order to achieve the above-mentioned objectives, as a first aspect of the present invention, an integrally molded composite lead structure is proposed, comprising a gate lead part and a cathode lead part, and an insulating layer that electrically insulates the gate lead part and the cathode lead part from each other, wherein the gate lead part, the insulating layer and the cathode lead part are integrally molded to form a "sandwich" structure.

[0011] Wherein, the gate lead-out portion is ring-shaped or sheet-shaped and is electrically connected to the gate spokes; and / or

[0012] Wherein, the cathode lead-out portion is ring-shaped or sheet-shaped; and / or

[0013] Wherein, the insulating layer between the gate lead-out portion and the cathode lead-out portion is made of a ceramic dielectric material; and / or

[0014] Wherein, the thickness of the insulating layer is less than or equal to 2 mm; and / or

[0015] Wherein, the gate lead-out portion is further connected to a gate spoke, and the cathode lead-out portion is formed with a groove at a position overlapping with the gate spoke, so that the gate spoke is embedded; and / or

[0016] The gate lead-out part and the cathode lead-out part are led out from the surface wiring layer through a through-hole technology, and the gate and cathode lead-out terminals are alternately distributed.

[0017] Wherein, the insulating layer between the gate lead-out portion and the cathode lead-out portion is made of aluminum oxide, aluminum nitride or silicon nitride, or a foam structure thereof; and / or

[0018] Wherein, a coating treatment is performed on the surface of the contact portion between the cathode lead-out portion and the gate spoke, and the coating material is a ceramic-based insulating wear-resistant material; and / or

[0019] Wherein, the gate spokes are sleeved with an insulating heat-resistant sleeve; and / or

[0020] The space where the gate lead-out part contacts the cathode lead-out part is filled with glue.

[0021] As a second aspect of the present invention, a power device packaging tube shell is further provided, wherein the power device packaging tube shell adopts the above-mentioned integrally formed composite lead structure.

[0022] As a third aspect of the present invention, a method for manufacturing an integrally formed composite lead structure is also proposed, comprising the following steps:

[0023] forming an active metal brazing material layer on the surface of the ceramic plate serving as an insulating layer;

[0024] The upper and lower copper strips used to make the cathode lead-out part and the gate lead-out part are respectively welded or sintered together with the ceramic plate, the working atmosphere is an inert atmosphere or a vacuum environment, and the temperature is less than 900°C; thereby forming a "sandwich" structure consisting of the gate lead-out part, the insulating layer and the cathode lead-out part.

[0025] Wherein, the ceramic plate is made of alumina, aluminum nitride, or silicon nitride insulating ceramic and is in a ring shape; and / or

[0026] Wherein, the thickness of the ceramic plate is less than or equal to 2 mm; and / or

[0027] Wherein, the active metal solder layer is prepared by a mixed paste material having adhesiveness, and the mixed paste material is an Ag-based solder containing active elements Ti and Zr; and / or

[0028] Wherein, the gate lead-out portion is in a ring shape or a sheet shape; and / or

[0029] Wherein, the cathode lead-out portion is ring-shaped or sheet-shaped; and / or

[0030] The gate lead-out part is also connected to a gate spoke, and the cathode lead-out part is pre-grooved at the position overlapping with the gate spoke, so that the gate spoke is embedded, thereby preventing the cathode lead-out part from crushing the gate spoke.

[0031] The manufacturing method further comprises coating the portion of the gate spoke in contact with the cathode lead-out portion, wherein the coating is made of a ceramic-based insulating wear-resistant material; and / or

[0032] Wherein, the manufacturing method further comprises sleeve-forming an insulating heat-resistant sleeve on the gate spokes; and / or

[0033] The manufacturing method further comprises the step of injecting glue into the portion of the gate spoke that contacts the cathode lead-out portion; and / or

[0034] Wherein, the cathode lead-out part comprises a cathode lead-out ring and a tube shell cathode shed, and the manufacturing method further comprises the steps of laminating the cathode lead-out ring and the tube shell cathode shed on the cathode surface of the integrally formed composite lead structure prepared by the above steps and having a nano silver paste applied on the surface, and forming an integral body by pressure sintering; and / or

[0035] Among them, the gate lead-out part includes a gate lead-out ring, and the manufacturing method also includes the step of laminating the gate lead-out ring on the gate surface of the one-piece composite lead structure prepared by the above steps, the surface of which is applied with nano silver paste, and forming it into an integrated one by pressure sintering.

[0036] As a fourth aspect of the present invention, a method for manufacturing a power device packaging tube shell is also proposed, comprising the following steps:

[0037] The one-piece composite lead structure is manufactured by the manufacturing method of the one-piece composite lead structure as described above;

[0038] The one-piece composite lead structure is welded with the ceramic ring and the anode electrode shed, and then installed in a packaging tube shell;

[0039] Injecting sealant along the bottom of the packaging tube shell to package the power device;

[0040] For high temperature curing of sealant, insulation level>50V, operating temperature≥150℃.

[0041] As a fifth aspect of the present invention, a power device using the above-mentioned integrally formed composite lead structure is also proposed, wherein the power device is an IGBT or an IGCT.

[0042] As a sixth aspect of the present invention, an electronic device is further proposed, wherein the electronic device uses the power device described above as a control element and / or a current / voltage switching element.

[0043] Based on the above technical solutions, it can be seen that the one-piece composite lead structure, package shell, manufacturing method thereof and power device of the present invention have at least one of the following beneficial effects compared with the prior art:

[0044] (1) The present invention adopts a pre-formed "sandwich" structure, which can realize the design of a low-inductance tube shell and minimize the integrated inductance of the device drive circuit;

[0045] (2) The present invention adopts coating plus insulating sleeve technology, which can improve the reliability of the device, and further reduce the mutual inductance between the current paths, improve the uniformity of the device current distribution, and thus improve the reliability of the device;

[0046] (3) The present invention adopts the glue injection technology to completely fill the space between the gate and cathode lead rings, ensuring reliable insulation of the drive circuit and further improving the sealing of the tube shell;

[0047] (4) The present invention provides a design method for a low-inductance tube shell. Through the preformed "sandwich" structure, the commutation area of ​​the circuit is reduced, the stray inductance of the circuit is reduced, and the lead-out of the device drive circuit is realized; further, high-temperature resistant insulating glue is filled at the gate and cathode welding positions to improve the insulation and sealing performance of the tube shell; further, the gate lead-out spokes are designed with an insulating coating and an insulating sleeve to further reduce the mutual inductance between the current paths, improve the uniformity of the device current distribution, and thus improve the reliability of the device. This is of great significance for reducing device parasitic parameters and improving the device's large current shutdown capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The method and device of the present invention are further described below in conjunction with the accompanying drawings and embodiments:

[0049] Figure 1 It is an exploded view of the existing press-fit packaging structure;

[0050] Figure 2A and 2B It is a schematic diagram of the gate and cathode lead-out structure in the existing tube shell structure;

[0051] Figure 3A and 3B It is a schematic diagram of the gate and cathode lead-out structure in a tube shell structure according to an embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of the drive circuit lead-out structure of an embodiment of the present invention;

[0053] Figure 5A and 5B are top and side views of a sandwich structure of one embodiment of the present invention;

[0054] Figure 6 is a flow chart of a tube shell preparation method according to an embodiment of the present invention;

[0055] Figure 7 is a structural schematic diagram of a tube shell driving circuit according to another embodiment of the present invention;

[0056] Figure 8 is a top view of the structure of a tube shell driving circuit according to another embodiment of the present invention;

[0057] Fig. 9 It is a structural side view of a tube shell driving circuit according to another embodiment of the present invention.

[0058] In the above drawings, the meanings of the reference numerals are as follows:

[0059] 1-ceramic ring; 2-"sandwich" structure; 3-anode electrode; 4-gate; 5-cathode electrode; 6-cathode; 9-gate spokes; 11-tube shell cover; 12-insulating sleeve; 13-anode sheet; 14-wafer; 15-cathode sheet; 16-gate ring; 17-gate gasket; 18-gate insulating seat; 19-gate lead spokes; 20-tube seat; 21-anode electrode umbrella skirt; 22-cathode lead ring; 23-gate lead ring; 31, 31′-gasket; 32, 32′-elastic sheet; 33, 33′-copper layer; 34-ceramic layer; 35-drive circuit lead; 41-surface wiring layer; 42-insulating ceramic layer; 43-gate lead layer; 44-cathode lead layer. DETAILED DESCRIPTION

[0060] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0061] In the present invention, some abbreviations and key terms are defined as follows:

[0062] GCT: abbreviation of Gate-Commutated Thyristor, gate-commutated thyristor;

[0063] IGCT: abbreviation of Integrated Gate-Commutated Thyristor, integrated gate-commutated thyristor;

[0064] IGBT: abbreviation of Insulated Gate Bipolar Transistor, insulated gate bipolar transistor;

[0065] GTO: abbreviation of GateTurn-Off Thyristor, gate turn-off thyristor;

[0066] P-type semiconductor: a semiconductor doped with P-type (Positive, hole-type positively charged) ions;

[0067] N-type semiconductor: a semiconductor doped with N-type (Negative, negatively charged electrons) ions;

[0068] PN junction: abbreviation of PN junction, a PN interface composed of P-type semiconductor and N-type semiconductor.

[0069] As shown in Figures 3-6, in order to optimize the packaging structure, reduce the difficulty of assembly processing, optimize the packaging parasitic parameters, and improve the device yield, the present invention proposes an integrally molded composite lead structure, including a gate lead part and a cathode lead part, and an insulating layer that electrically insulates the gate lead part and the cathode lead part from each other, wherein the gate lead part, the insulating layer and the cathode lead part are integrally molded to form a "sandwich" structure.

[0070] Wherein, the gate lead-out portion is, for example, ring-shaped or sheet-shaped. Figure 4 As shown, the gate lead-out portion is, for example, a gate lead-out ring 23, which can be electrically connected to the centrally symmetrical gate spokes 9 so as to evenly distribute the current flowing through the gate.

[0071] Wherein, the cathode lead-out portion is, for example, ring-shaped or sheet-shaped. Figure 4 As shown, the cathode lead-out portion is a cathode lead-out ring 22 .

[0072] The insulating layer between the gate lead-out part and the cathode lead-out part is realized by a dielectric material structure such as a ceramic plate, preferably a ceramic foam layer or a ceramic plate, and the specific material can be insulating ceramics such as alumina, aluminum nitride, silicon nitride, or their foamed structure. The thickness of the insulating layer is less than or equal to 2 mm. When the thickness of the insulating layer is greater than or equal to 1 mm, a ceramic foam material can be used to reduce the weight of the structure; when the thickness of the insulating layer is less than 1 mm, a solid insulating ceramic is used to increase the strength of the structure.

[0073] Among them, the gate lead part and the cathode lead part can be prepared by laminating or welding a copper tape on an insulating layer, or can also be made by stamping a metal sheet such as a copper sheet, welding it, and then connecting it to the insulating part through welding, bonding, and other techniques.

[0074] Among them, Figure 3A , 3B As shown, the anode electrode shed 21 connected to the anode 3 is separated from the cathode lead ring 22 (connected to the cathode electrode 5) and the gate lead ring 23 by a ceramic ring 1. The gate lead part and the cathode lead part are separated by only an insulating ceramic layer formed by a ceramic plate, and are two parallel planes; the gate spoke 9 is in the same plane as the cathode lead part. Preferably, the cathode lead part (cathode lead ring 22) is formed with a groove at the position overlapping with the gate spoke 9, so that the gate spoke 9 is embedded to prevent the cathode lead part from crushing the gate spoke 9.

[0075] The portion of the gate spoke 9 that is in contact with the cathode lead-out portion is subjected to coating treatment, and the material of the coating may be an insulating wear-resistant material system such as a ceramic base.

[0076] The gate spokes 9 are sleeved with an insulating heat-resistant sleeve to prevent the device from being subjected to long-term thermal and electrical stresses, which may cause a short circuit in the device and improve the reliability of the device.

[0077] The position where the gate spokes 9 contact the cathode lead-out portion is filled with glue.

[0078] The cathode lead-out part includes a cathode lead-out ring 22 and a tube shell cathode shed, which are attached to the cathode surface of the aforementioned "sandwich" structure 2 with nano silver paste applied on the surface, and are formed into one by pressure sintering.

[0079] The gate lead-out part includes a gate lead-out ring 23, which is attached to the gate surface of the aforementioned "sandwich" structure 2 with nano silver paste applied on the surface, and is formed into one piece through pressure sintering.

[0080] The present invention further discloses a packaging tube shell of a power device, wherein the packaging tube shell of the power device adopts the above-mentioned integrally formed composite lead structure.

[0081] like Figure 6 As shown, the present invention also discloses a method for manufacturing an integrally formed composite lead structure, comprising:

[0082] An active metal brazing material layer is formed on the surface of the ceramic plate; wherein the ceramic plate is made of insulating ceramics such as alumina, aluminum nitride, silicon nitride, etc., and is in a ring shape; the active metal brazing material layer can be prepared by a mixed paste material with adhesiveness, and the mixed paste material is generally an Ag-based solder containing active elements Ti and Zr, and has good welding wettability to ceramics and copper;

[0083] The upper and lower copper strips used to make the cathode lead-out part and the gate lead-out part are respectively welded or sintered to the insulating ceramic layer formed by the ceramic plate. The welding / sintering atmosphere is an inert atmosphere or a vacuum environment. The welding / sintering temperature is less than 900°C, for example, 180°C, 220°C, 350°C, 500°C, 650°C, etc.

[0084] The gate lead-out portion is, for example, in a ring shape or a sheet shape.

[0085] The cathode lead-out portion is, for example, ring-shaped or sheet-shaped.

[0086] Wherein, the thickness of the insulating ceramic layer formed by the ceramic plate is less than or equal to 2 mm.

[0087] Among them, Figure 5A , 5BAs shown, the gate lead-out part (gate lead-out ring, copper layer 33), ceramic layer 34, and cathode lead-out part (cathode lead-out ring, copper layer 33′) are stacked into a "sandwich" structure 2. The gate lead-out part (gate lead-out ring, copper layer 33) and the cathode lead-out part (cathode lead-out ring, copper layer 33′) are separated by only a ceramic layer 34 formed by a ceramic plate, and are two parallel and close-together planes; the gate spokes are in the same plane as the cathode lead-out part (cathode lead-out ring). Preferably, the cathode lead-out part is formed with a groove at the position overlapping with the gate spokes, so that the gate spokes are embedded to prevent the cathode lead-out part from crushing the gate spokes.

[0088] The portion of the gate spoke in contact with the cathode lead-out portion is coated, and the material of the coating may be an insulating and wear-resistant material system such as a ceramic base; and / or, the gate spoke is covered with an insulating and temperature-resistant sleeve to prevent the device from being subjected to long-term thermal and electrical stress, resulting in a short circuit of the device, thereby improving the reliability of the device.

[0089] The manufacturing method further comprises the step of attaching the cathode lead ring and the tube shell cathode shed to the cathode surface of the aforementioned integrally formed composite lead structure with nano silver paste applied on the surface, and forming an integral body by pressure sintering.

[0090] The manufacturing method further comprises the step of laminating a gate lead-out ring on the gate surface of the aforementioned integrally formed composite lead structure with nano silver paste applied on the surface, and forming an integral body by pressure sintering.

[0091] The manufacturing method further comprises the step of injecting glue into the contact portion between the gate spoke and the cathode lead-out portion.

[0092] like Figure 1-6 As shown, the present invention also discloses a method for manufacturing a packaging tube shell of a power device, comprising the following steps:

[0093] The one-piece composite lead structure is manufactured by the manufacturing method of the one-piece composite lead structure as described above;

[0094] The one-piece composite lead structure is welded with the ceramic ring 1 and the anode electrode shed 21;

[0095] Injecting sealant along the bottom of the tube shell to encapsulate the power device;

[0096] For high temperature curing of sealant, insulation level>50V, operating temperature≥150℃.

[0097] The present invention also discloses a power device using the above-mentioned integrally formed composite lead structure, wherein the power device is, for example, an IGBT or an IGCT.

[0098] The present invention also discloses a power semiconductor device using the above-mentioned integrally formed composite lead structure, wherein the power semiconductor device is, for example, a device using IGBT, IGCT, etc. as a control element and / or a switching element, such as a converter valve, etc.

[0099] In a preferred embodiment, the one-piece composite lead structure and the manufacturing method thereof of the present invention are as follows:

[0100] (1) Low-sensitivity tube shell design

[0101] The present invention introduces a "sandwich" structure to preform the gate lead ring 23 and the cathode lead shed through a specific process, and then connects the upper electrode shed (i.e., the anode electrode shed), the ceramic ring 1 and the lower electrode (i.e., the cathode) through welding technology; thereby, the drive loop electrode is led out at a very close distance, and the parasitic inductance of the drive loop is reduced to the maximum extent; at the same time, the ceramic ring 1 is an integral structure, which greatly improves the tube shell yield; the tube shell gate lead ring 23 and the cathode lead part are filled with a glue injection process to achieve further sealing and insulation.

[0102] (2) Low-inductance tube shell implementation process

[0103] (I) Preformed “sandwich” structure: enables extremely low inductance lead-out of the device drive circuit.

[0104] in:

[0105] ① The surface of the ceramic plate is printed with active metal brazing filler metal; the ceramic plate can be insulating ceramics such as alumina, aluminum nitride, silicon nitride, etc., and the shape is ring-shaped; the active brazing filler metal can be a mixed paste material with adhesiveness, generally an Ag-based solder containing active elements Ti and Zr, which has good welding wettability for ceramics and copper. The thickness of the ceramic plate can be adjusted according to the thickness of the driver board, and the thickness is ≤2 mm;

[0106] ② Copper tape patch; the copper tape is CU-OFE (copper content > 99.99%, oxygen < 0.0005%), thickness < 0.5μm.

[0107] ③ Vacuum welding: weld the upper and lower copper strips to the ceramic plate in an inert atmosphere or vacuum environment, with a welding temperature of <900°C and a welding porosity of <5%;

[0108] ④ The gate lead ring 23, the tube shell cathode shed and the "sandwich" structure are sintered;

[0109] First, nano silver paste is printed on the copper layer on the surface of the "sandwich" structure, and then it is dried (temperature 130~180℃ / 30~60 min). Finally, the cathode lead-out ring 22, the cathode umbrella skirt of the tube shell and the corresponding position of the "sandwich" structure are fitted to complete pressure sintering (10~30 MPa / 250~300℃ / 5~10 min).

[0110] Among them, the printing process involved above is completed by a customized screen printing fixture. The fixture can be designed as a whole-surface ring structure or a "net" structure. The purpose of designing it as a "net" structure is to make it more conducive to the release of organic matter during the baking process of large-area silver paste and improve the sintering quality.

[0111] The gate lead-out structure is a spoke type, and the gate 4 is led out by crimping:

[0112] The gate lead spoke 19 is coated at the cathode contact part of the tube shell. The coating can be an insulating and wear-resistant material system such as a ceramic base. At the same time, during the final assembly, the gate spoke 9 will be covered with an insulating and temperature-resistant sleeve to prevent the device from being subjected to long-term thermal and electrical stress, resulting in a short circuit of the device, thereby improving the reliability of the device.

[0113] The cathode electrode 5 of the tube shell is grooved at the contact portion with the gate spoke 9 so that the gate spoke 9 can be embedded, thereby preventing the cathode electrode 5 from crushing the gate spoke.

[0114] (II) Tube and shell welding.

[0115] ① The ceramic ring 1 and the anode electrode shed 21 are welded to the above structure;

[0116] ② Glue injection: inject sealant along the bottom of the tube shell, the thickness of the glue injection can submerge the surface of the gate lead ring 23, but lower than the cathode electrode 5;

[0117] ③Curing: high temperature oxygen-free oven, 150~200℃ / 30~120 min;

[0118] The above silicone has sealing properties after curing, and the insulation level is greater than 50V, and the operating temperature is greater than or equal to 150°C.

[0119] The present invention will be further described below through specific examples. It should be noted that the following examples are only for illustration and are not intended to limit the present invention.

[0120] As shown in Figures 3-9, the specific steps of Examples 1 and 2 are as follows; in Example 1, the gate and cathode are led out in upper and lower layers; in Example 2, the gate and cathode are led out on the same side through through-hole technology.

[0121] Example 1: Pre-prepare the "sandwich" structure first, then weld the tube shell (gate and cathode lead up and down)

[0122] ① Such as Figure 6 As shown, active metal solder is printed on the surface of the ceramic plate; the ceramic plate can be insulating ceramics such as alumina, aluminum nitride, silicon nitride, etc., and has a ring shape; the active solder can be a mixed paste material with adhesiveness, generally an Ag-based solder containing active elements Ti and Zr, and has good welding wettability to ceramics and copper.

[0123] ② Copper tape patch; the copper tape is CU-OFE (copper content > 99.99%, oxygen < 0.0005%), thickness < 0.5μm.

[0124] ③ Vacuum welding: welding the surface wiring layer 41 formed by the upper and lower copper strips to the ceramic plate as the insulating ceramic layer 42, the welding atmosphere is an inert atmosphere or a vacuum environment, the welding temperature is less than 900°C, and the welding void rate is required to be less than 5%;

[0125] ④ The gate lead ring 23, the tube shell cathode shed and the "sandwich" structure 2 are sintered;

[0126] First, nano silver paste is printed on the copper layer on the surface of the "sandwich" structure, and then it is dried (temperature 130~180℃ / 30~60min). Finally, the cathode lead-out ring 22, the cathode umbrella skirt of the tube shell and the corresponding position of the "sandwich" structure 2 are fitted to complete pressure sintering (10~30 MPa / 250~300℃ / 5~10 min).

[0127] ⑤ The ceramic ring 1 and the anode electrode shed 21 are welded to the above structure;

[0128] ⑥ Glue injection: Inject sealant along the bottom of the tube shell. The thickness of the glue injection should submerge the surface of the gate lead ring 23, but be lower than the cathode electrode 5;

[0129] ⑦Curing: high temperature oxygen-free oven, 150~200℃ / 30~120 min.

[0130] Example 2: Pre-prepare the "sandwich" structure first, then weld the tube shell (gate and cathode are led out on the same side)

[0131] like Figure 7 As shown, the anode electrode 3 is separated from the drive circuit lead 35 by the ceramic ring 1, and the drive circuit lead 35 includes a line connected to the gate lead ring 23 and the cathode lead ring 22 (connected to the cathode electrode 5).

[0132] like Figure 8-9 As shown, this embodiment 2 is further configured as follows: through a multi-layer "sandwich" structure 2 (for example, Fig. 9The gate lead layer 43 and the cathode lead layer 44 are separated by two insulating ceramic layers 42 as shown, and the gate lead ring 23 (connected to the gate 4) and the cathode lead ring 22 (connected to the cathode 6) are placed in the same plane. On the one hand, a low loop parasitic inductance is still maintained, and on the other hand, the connection between the gate 4, the cathode 6 and the driving board is simplified, the packaging cost is reduced, and maintenance is easy.

[0133] ① The preparation process of the multi-layer "sandwich" structure is the same as that of Example 1;

[0134] ② The multi-layer "sandwich" structure is divided into a gate lead-out layer 43 formed by a gate lead-out part and a cathode lead-out layer 44 formed by a cathode lead-out part, which are led out from the surface wiring layer 41 through a through-hole technology. The thickness and width of the three-layer copper foil are determined by the current requirement of the device;

[0135] ③ The gate and cathode lead terminals are distributed alternately, which helps to evenly distribute the current;

[0136] ④ The connection between the tube shell ceramic ring and the electrode is achieved by welding process, and its process requirements are the same as those in Example 1;

[0137] ⑤ The sealing of the tube shell is completely achieved by the "glue injection" process, and its process and requirements are the same as those in Example 1.

[0138] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An integrally formed composite lead structure, characterized in that: It includes a gate lead-out part and a cathode lead-out part, and an insulating layer that electrically insulates the gate lead-out part and the cathode lead-out part from each other, wherein the gate lead-out part, the insulating layer and the cathode lead-out part are integrally formed to form a "sandwich" structure; Wherein, the insulating layer between the gate lead-out portion and the cathode lead-out portion is made of a ceramic dielectric material having a thickness of less than or equal to 2 mm; when the thickness of the insulating layer is greater than or equal to 1 mm, a ceramic foam material is used; and when the thickness of the insulating layer is less than 1 mm, a solid ceramic material is used; The gate lead-out portion is also connected to a gate spoke, and the cathode lead-out portion is formed with a slot at a position overlapping with the gate spoke, so that the gate spoke is embedded; the gate spoke and the cathode lead-out portion are in the same plane; The one-piece forming method includes: welding or sintering the upper and lower copper strips used to make the cathode lead-out part and the gate lead-out part respectively with the ceramic dielectric material as the insulating layer, the working atmosphere is an inert atmosphere or a vacuum environment, and the temperature is less than 900°C; thereby forming a "sandwich" structure consisting of the gate lead-out part, the insulating layer and the cathode lead-out part.

2. The one-piece composite lead structure according to claim 1, characterized in that: The gate lead-out portion is in a ring or sheet shape and is electrically connected to the gate spokes; and / or The cathode lead-out portion is ring-shaped or sheet-shaped; and / or The gate lead-out part and the cathode lead-out part are led out from the surface wiring layer through a through-hole technology, and the gate and cathode lead-out terminals are alternately distributed.

3. The integrally formed composite lead structure according to claim 2, characterized in that: The insulating layer between the gate lead-out portion and the cathode lead-out portion is made of aluminum oxide, aluminum nitride or silicon nitride, or a foam structure thereof; and / or A coating treatment is performed on the surface of the contact portion between the cathode lead-out portion and the gate spoke, and the coating material is a ceramic-based insulating wear-resistant material; and / or The gate spokes are sleeved with an insulating heat-resistant sleeve; and / or The position where the gate lead-out portion contacts the cathode lead-out portion is filled with glue.

4. A power device packaging tube shell, characterized in that: The packaging tube shell of the power device adopts the integrally formed composite lead structure as claimed in any one of claims 1 to 3.

5. A method for manufacturing an integrally formed composite lead structure, characterized in that: include: An active metal brazing material layer is formed on the surface of a ceramic plate as an insulating layer; wherein the thickness of the ceramic plate is less than or equal to 2 mm; when the thickness of the ceramic plate is greater than or equal to 1 mm, the ceramic plate is made of a ceramic foam material; and when the thickness of the ceramic plate is less than 1 mm, the ceramic plate is made of a solid ceramic dielectric material; The upper and lower copper strips used to make the cathode lead-out part and the gate lead-out part are respectively welded or sintered together with the ceramic plate, and the working atmosphere is an inert atmosphere or a vacuum environment, and the temperature is less than 900°C; thereby forming a "sandwich" structure consisting of the gate lead-out part, the insulating layer and the cathode lead-out part; wherein the gate lead-out part is also connected to the gate spoke, and the cathode lead-out part is formed with a groove at a portion overlapping with the gate spoke, so that the gate spoke is embedded; the gate spoke and the cathode lead-out part are in the same plane.

6. The manufacturing method according to claim 5, characterized in that: The ceramic plate is made of alumina, aluminum nitride, or silicon nitride insulating ceramic and is annular in shape; and / or The active metal solder layer is prepared by a mixed paste material having adhesiveness, wherein the mixed paste material is an Ag-based solder containing active elements Ti and Zr; and / or The gate lead-out portion is ring-shaped or sheet-shaped; and / or The cathode lead-out portion is in a ring shape or a sheet shape.

7. The manufacturing method according to claim 6, characterized in that: The manufacturing method further comprises coating the portion of the gate spoke in contact with the cathode lead-out portion, wherein the coating is made of a ceramic-based insulating wear-resistant material; and / or The manufacturing method further comprises sleeve-mounting an insulating heat-resistant sleeve on the gate spokes; and / or The manufacturing method further comprises the step of injecting glue into the portion of the gate spoke that contacts the cathode lead-out portion; and / or The cathode lead-out part includes a cathode lead-out ring and a tube shell cathode shed, and the manufacturing method further includes the steps of laminating the cathode lead-out ring and the tube shell cathode shed on the cathode surface of the integrally formed composite lead structure prepared by the above steps and having nano silver paste applied on the surface, and forming an integral body by pressure sintering; and / or The gate lead-out part includes a gate lead-out ring, and the manufacturing method also includes the step of attaching the gate lead-out ring to the gate surface of the one-piece composite lead structure prepared by the above steps and having nano silver paste applied on the surface, and forming it into one piece by pressure sintering.

8. A method for manufacturing a power device packaging tube shell, characterized in that: The steps include: The one-piece composite lead structure is manufactured by the manufacturing method of the one-piece composite lead structure according to any one of claims 5 to 7; The one-piece composite lead structure is welded with the ceramic ring and the anode electrode shed, and then installed in a packaging tube shell; Injecting sealant along the bottom of the packaging tube shell to package the power device; For high temperature curing of sealant, insulation level>50V, operating temperature≥150℃.

9. A power device using the integrally formed composite lead structure according to any one of claims 1 to 3, wherein the power device is an IGBT or an IGCT.

10. An electronic device, wherein the power device according to claim 9 is used as a control element and / or a current / voltage switching element.

11. The electronic device according to claim 10, characterized in that: The electronic device is a flow control valve.

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