Method for suppressing IGCT turn-off tail oscillation, crimped IGCT and its application

Abstract

A method for suppressing IGCT turn-off tail oscillation, a crimped IGCT and applications. The method for suppressing IGCT turn-off tail oscillation comprises: replacing the cathode metal connecting piece of the IGCT with a cathode metal connecting piece with a boss structure, or forming a boss structure on the cathode metal connecting piece of the IGCT; and embedding a soft magnetic ring at the boss position. The present invention effectively suppresses the turn-off tail current oscillation of the crimped IGCT device packaged in the whole wafer, and improves the reliability of the device application system; the present invention is completed by improving the existing crimped IGCT device packaging form, and the assembly is simple. The soft magnetic material used only works under low current conditions and does not affect the electrical parameters of the device during normal operation; the soft magnetic ring used can be adjusted to one or more layers according to actual needs, which is flexible and convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a method for suppressing IGCT turn-off tail oscillation, a crimped IGCT and applications thereof, which are used for optimizing the switching characteristics of IGCT devices. Background Art

[0002] IGCT (Integrated Gate Commutated Thyristor) is a thyristor that combines the characteristics of GTO (gate turn-off) thyristor and MOSFET (metal oxide semiconductor field effect transistor), integrating the advantages of these two devices to improve the overall efficiency and performance of high-power applications. IGCT integrates the packaged whole-wafer gate commutated thyristor and gate drive circuit on the printed circuit board using an interconnection design. It has high voltage and current capacity and reliability, low on-state voltage drop and production cost, and has significant advantages in application fields such as power grids and variable speed drives.

[0003] When testing the switching characteristics of IGCT under specific working conditions, the tail oscillation of IGCT will cause the voltage and current to oscillate sharply. The typical tail oscillation test waveform of IGCT is as follows: Figure 1 As shown (the oscillation part is marked with a solid box), the conducted and radiated electromagnetic interference of the high-frequency oscillation also has an important impact on the control system and the electromagnetic environment. Suppressing the tail oscillation of the IGCT is very important for the safe and reliable operation of the system.

[0004] However, after technical search, it was found that there is no effective suppression solution for the turn-off tail oscillation of IGCT in the existing technology, so it is urgent to develop relevant technologies to solve this problem. Summary of the invention

[0005] In view of this, the main purpose of the present invention is to provide a method for suppressing IGCT turn-off tail oscillation, a crimped IGCT and applications, in order to at least partially solve the above technical problems.

[0006] In order to achieve the above object, as a first aspect of the present invention, a method for suppressing IGCT turn-off tail oscillation is proposed, comprising the following steps:

[0007] Replacing the cathode metal connecting piece of the IGCT with a cathode metal connecting piece with a boss structure, or forming a boss structure on the cathode metal connecting piece of the IGCT;

[0008] A soft magnetic ring is embedded at the boss position.

[0009] As a second aspect of the present invention, a crimping type IGCT is also proposed, wherein the cathode metal connecting piece of the crimping type IGCT has a boss structure and is embedded with a soft magnetic ring.

[0010] As a third aspect of the present invention, a power device, electronic device or system using the crimped IGCT as described above is also proposed; wherein the power device is preferably a semiconductor switching device; the electronic device or system is preferably a converter, a static VAR compensator (SVC), a medium or high voltage motor drive or a high voltage transmission system.

[0011] Based on the above technical solutions, it can be seen that the method for suppressing the tail oscillation of the IGCT device when it is turned off, the crimped IGCT and the application of the present invention have at least one of the following beneficial effects compared with the prior art:

[0012] 1. Effectively suppress the turn-off tail current oscillation of the whole wafer packaged press-fit IGCT device, and improve the reliability of the device application system.

[0013] 2. Improvement is made on the existing crimped IGCT device packaging form, and assembly is simple.

[0014] 3. The soft magnetic material used only works under small current conditions. When the current is large, the saturated magnetic field strength is reached and the equivalent inductance is zero, which does not affect the electrical parameters of the device during normal operation.

[0015] 4. The soft magnetic ring used can be adjusted to one or more layers according to actual needs, which is flexible and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The method and device of the present invention are further described below in conjunction with the accompanying drawings and embodiments:

[0017] Figure 1 It is a schematic diagram of the tailing oscillation waveform of the IGCT device in the prior art;

[0018] Figure 2 is a schematic diagram of a compression packaging structure of an IGCT device in the prior art;

[0019] Figure 3 It is a schematic diagram of the IGCT device compression packaging structure for suppressing the device turn-off tail oscillation of the present invention;

[0020] Figure 4 is a top view of the IGCT chip structure of the present invention;

[0021] Figure 5 It is a schematic structural diagram of a soft magnetic ring according to an embodiment of the present invention;

[0022] Figure 6 It is a schematic structural diagram of a soft magnetic ring according to another embodiment of the present invention. DETAILED DESCRIPTION

[0023] 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.

[0024] In the present invention, some abbreviations and key terms are defined as follows:

[0025] GCT: abbreviation of Gate-Commutated Thyristor, gate-commutated thyristor;

[0026] IGCT: abbreviation of Integrated Gate-Commutated Thyristor, integrated gate-commutated thyristor;

[0027] IGBT: abbreviation of Insulated Gate Bipolar Transistor, insulated gate bipolar transistor;

[0028] GTO: abbreviation of GateTurn-Off Thyristor, gate turn-off thyristor;

[0029] P-type semiconductor: a semiconductor doped with P-type (Positive, hole-type positively charged) ions;

[0030] N-type semiconductor: a semiconductor doped with N-type (Negative, negatively charged electrons) ions;

[0031] PN junction: abbreviation of PN junction, a PN interface composed of P-type semiconductor and N-type semiconductor.

[0032] In order to overcome the deficiency of the prior art that there is no effective suppression scheme for the tail oscillation of IGCT turn-off, the present invention provides a packaging structure for suppressing the tail oscillation of IGCT turn-off. On the basis of the structure of the existing crimping IGCT packaging scheme, a cathode metal connecting piece with a boss structure is introduced to replace the traditional cathode metal connecting piece, and a soft magnetic ring is embedded, which can effectively suppress the tail oscillation of IGCT turn-off. Compared with the scheme in IGBT in the prior art, for example, disclosed in the Chinese patent application CN110931465A, in order to suppress the transit time oscillation of parallel IGBT chips in IGBT devices with similar packaging structures, a scheme of using soft magnetic materials to adhere to the circuit board under each circuit board is proposed, but multiple IGBT chips are used in parallel in the IGBT device, while the IGCT is a whole wafer package, and there is no transit time oscillation that needs to be suppressed in the parallel situation, so the suppression scheme of the IGBT device cannot be directly applied to the IGCT to obtain the scheme of the present invention.

[0033] Specifically, the present invention proposes a method for suppressing IGCT turn-off tail oscillation, comprising the following steps:

[0034] Replacing the cathode metal connecting piece of the IGCT with a cathode metal connecting piece with a boss structure, or forming a boss structure on the cathode metal connecting piece of the IGCT;

[0035] A soft magnetic ring is embedded at the boss position.

[0036] Prior to the present invention, the prior art did not provide an effective suppression scheme for the IGCT turn-off tail oscillation. The inventors found through experimental research that if a boss structure is formed on the cathode metal connecting sheet and a soft magnetic ring is set on it, the IGCT turn-off tail oscillation can be suppressed. This design idea is different from the soft magnetic ring design of IGBT. On the one hand, due to the use of a whole wafer in the IGCT, there are no longer several separate parallel circuit boards, so this position is different from the position of the lower end of each of the above circuit boards; on the other hand, under given temperature and operating voltage conditions, the generation of the turn-off tail oscillation depends on the parasitic inductance and parasitic resistance of the parasitic resonant circuit formed by the parallel chips. For the use of multiple IGBT chips in parallel in the IGBT device, it is easy to adjust the resonant circuit parameters through the parallel branch, while the IGCT is a whole wafer package, and the parameter adjustment of the resonant circuit cannot be directly analogized. After research, the inventors found that the effective suppression of the IGCT turn-off tail oscillation needs to be completed in conjunction with the IGCT chip comb structure and the cathode metal connecting sheet, which led to the present invention.

[0037] Therefore, if Figure 2 , 3 As shown, the existing crimped IGCT packaging structure includes: a tube shell upper cover 1, a cathode metal connecting piece 2, an IGCT chip 3, an anode metal connecting piece 4 and a tube shell base 5, and the present invention proposes an improved crimped IGCT packaging structure, which introduces a cathode metal connecting piece 6 with a boss structure to replace the traditional cathode metal connecting piece 2 on the basis of the structure of the existing crimped IGCT packaging solution, and embeds a soft magnetic ring 7 to suppress the turn-off tail oscillation of the IGCT.

[0038] The material of the cathode metal connecting plate 6 has a relatively high hardness, and its thermal expansion coefficient is close to that of the IGCT chip 3. Specifically, the material of the cathode metal connecting plate 6 is usually, for example, metal molybdenum, with a Mohs hardness of about 5.5, or a molybdenum-copper alloy with a hardness of HRC80. In contrast, the Mohs hardness of copper is only 3.0; the thermal expansion coefficient of molybdenum is about 4.9×10 -6 / K, the thermal expansion coefficient of Si IGCT chip is about 2.44×10 -6 / K, in contrast, the thermal expansion coefficient of copper is about 1.65×10 -5 / K.

[0039] Among them, the soft magnetic ring 7 can be sleeved on the boss, and a through hole is formed between the upper and lower surfaces of the soft magnetic ring 7, and the boss of the cathode metal connecting piece passes through the through hole. For example, the through hole of the soft magnetic ring 7 corresponds one-to-one with the boss of the cathode metal connecting piece 6.

[0040] The soft magnetic ring 7 may be a single layer or multiple layers, and the thickness of each layer is, for example, 0.1 mm.

[0041] The soft magnetic ring 7 is made of soft magnetic material, such as nickel-iron material or permalloy material.

[0042] The through holes of the soft magnetic ring 7 can have a variety of layout schemes, for example, they can correspond one-to-one with the bosses of the cathode metal connecting sheet 6, or can correspond one-to-one with the cathode comb bars of the IGCT chip 3, or the IGCT chip can be divided into equal parts at will. Figure 4 As shown, it includes cathode comb bars 301, gate ring 302, surface insulating layer 303, and chip terminal 304. Cathode comb bars 301 are slightly higher than surface insulating layer 303, and are electrically connected to cathode metal connecting sheet 2 through pressure contact.

[0043] The present invention further proposes a crimping type IGCT, wherein the cathode metal connecting piece 6 of the crimping type IGCT has a boss structure and a soft magnetic ring 7 is embedded therein.

[0044] The material of the cathode metal connecting plate 6 has a relatively high hardness, for example, a Mohs hardness between 5 and 6, preferably 5.5 (ie, metal molybdenum); and a thermal expansion coefficient close to that of the IGCT chip 3 .

[0045] Among them, the soft magnetic ring 7 can be sleeved on the boss, and a through hole is formed between the upper and lower surfaces of the soft magnetic ring 7, and the through hole passes through the boss of the cathode metal connecting piece. For example, the through hole of the soft magnetic ring 7 corresponds one-to-one with the boss of the cathode metal connecting piece 6.

[0046] The soft magnetic ring 7 may be a single layer or multiple layers, and the thickness of each layer is, for example, 0.1 mm.

[0047] The material of the soft magnetic ring 7 is a soft magnetic material, such as nickel-iron material or permalloy material. The soft magnetic ring 7 has the following characteristics: when the circuit surrounded by the ring has a small current, the magnetic permeability is large and the inductance of the ring is also large; when the circuit surrounded by the ring has a large current, the ring is magnetically saturated and the inductance of the ring is zero, that is, the soft magnetic material only works in the low current stage.

[0048] The through holes of the soft magnetic ring 7 may have a variety of layout schemes, for example, they may correspond one-to-one with the bosses of the cathode metal connecting sheet 6, or may correspond one-to-one with the cathode combs of the IGCT chip 3, or the IGCT chip may be divided into equal parts arbitrarily.

[0049] The present invention also proposes a power device and an electronic device / system using the above-mentioned crimped IGCT. The power device is, for example, a semiconductor switch device, and the electronic device / system is, for example, a converter, a static VAR compensator (SVC), a medium- and high-voltage motor driver, or a high-voltage power transmission system.

[0050] 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.

[0051] The embodiment of the present invention proposes two implementation methods of the crimping type IGCT, the main difference between which is the different structures of the soft magnetic ring 7. The structure of the soft magnetic ring 7 is mainly achieved by Figure 5 and Figure 6 The two solutions shown are implemented.

[0052] Example 1

[0053] Embodiment 1 claims protection for a crimped IGCT, wherein the cathode metal connecting piece 6 of the crimped IGCT has a boss structure and a soft magnetic ring 7 is embedded therein.

[0054] In such Figure 5 In the scheme 1 shown, the soft magnetic ring 7 includes a soft magnetic material 701 and a through hole 702. The through hole 702 should be larger than the boss structure of the cathode metal connecting piece 6, and the boss structure of the cathode metal connecting piece 6 passes through the through hole 702 of the soft magnetic ring 7. The cathode comb bar 301, the boss structure of the cathode metal connecting piece 6, and the through hole 702 of the soft magnetic ring 7 correspond to each other.

[0055] Example 2

[0056] Embodiment 2 claims protection for a crimped IGCT, wherein the cathode metal connecting piece 6 of the crimped IGCT has a boss structure and a soft magnetic ring 7 is embedded therein.

[0057] In such Figure 6In the scheme 2 shown, the soft magnetic ring 7 includes a soft magnetic material 703 and a through hole 704. The through hole 704 should be larger than the boss structure of the cathode metal connecting piece 6, and the boss structure of the cathode metal connecting piece 6 passes through the through hole 704 of the soft magnetic ring 7. The boss structure of the cathode metal connecting piece 6 corresponds one-to-one with the through hole 702 of the soft magnetic ring 7. The boss structure of the cathode metal connecting piece 6 is connected to a plurality of the cathode comb bars 301. The through hole 704 can divide the soft magnetic ring 7 into any equal parts ( Figure 6 A schematic diagram of the structure divided into four equal parts is given in FIG.

[0058] 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. A method for suppressing IGCT turn-off tail oscillation, characterized in that: The following steps are involved: The cathode metal connecting piece of the IGCT is replaced with a cathode metal connecting piece with a boss structure, or a boss structure is formed on the cathode metal connecting piece of the IGCT; wherein the boss of the cathode metal connecting piece is connected to the cathode comb bars of multiple IGCT chips and arbitrarily divides the IGCT chips into equal parts, and the boss of the cathode metal connecting piece does not correspond one-to-one to the cathode comb bars of the multiple IGCT chips; a through hole is formed between the upper and lower surfaces of the soft magnetic ring, the boss of the cathode metal connecting piece passes through the through hole, and the through hole of the soft magnetic ring corresponds one-to-one to the boss of the cathode metal connecting piece.

2. The method according to claim 1, characterized in that The cathode metal connecting piece is made of metal molybdenum or molybdenum-copper alloy.

3. The method according to claim 1, characterized in that The soft magnetic ring is multi-layered; and / or The thickness of each layer of the soft magnetic ring is 0.1 to 1 mm; and / or The material of the soft magnetic ring is soft magnetic material; and / or The total thickness of the soft magnetic ring is less than the height of the boss on the cathode metal connecting piece.

4. The method according to claim 3, characterized in that The thickness of each layer of the soft magnetic ring is 0.1 mm; and / or The soft magnetic ring is made of nickel-iron alloy material or permalloy material.

5. A crimping type IGCT, characterized in that: The cathode metal connecting piece of the crimped IGCT has a boss structure, wherein the boss of the cathode metal connecting piece is connected to the cathode comb bars of multiple IGCT chips and divides the IGCT chip into equal parts arbitrarily, and the boss of the cathode metal connecting piece does not correspond one-to-one to the cathode comb bars of the IGCT chip; a through hole is formed between the upper and lower surfaces of the soft magnetic ring, the boss of the cathode metal connecting piece passes through the through hole, and the through hole of the soft magnetic ring corresponds one-to-one to the boss of the cathode metal connecting piece.

6. The crimp-type IGCT according to claim 5, characterized in that: The cathode metal connecting piece is made of metal molybdenum or molybdenum-copper alloy.

7. The crimp-type IGCT according to claim 5, characterized in that: The soft magnetic ring is multi-layered; and / or The thickness of each layer of the soft magnetic ring is 0.1 to 1 mm; and / or The material of the soft magnetic ring is soft magnetic material; and / or The soft magnetic ring only works in the low current stage.

8. The crimp-type IGCT according to claim 7, characterized in that: The thickness of each layer of the soft magnetic ring is 0.1 mm; and / or The soft magnetic ring is made of nickel-iron alloy material or permalloy material.

9. A power device, electronic apparatus or system using the press-fit IGCT according to any one of claims 5 to 8.

10. The power device of the press-fit IGCT according to claim 9, characterized in that: The power device is a semiconductor switch device.

11. The electronic device or system of the crimp-type IGCT according to claim 9, characterized in that: The electronic device or system is a converter, a static VAR compensator, a medium or high voltage motor driver or a high voltage power transmission system.

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