Fuse and power module

Abstract

The utility model relates to the technical field of fuses, and discloses a fuse and a power module, and the fuse comprises a heat conduction substrate; the insulating substrate is arranged on the surface of the heat conducting substrate; the at least two current-carrying connection islands are attached to the insulating substrate, and every two adjacent current-carrying connection islands are connected through a conduction mechanism; the insulating substrate and the current-carrying connection island are both arranged in the shell; the shell is filled with an arc extinguishing filling material; the electrode is arranged outside the shell; and the electrode is connected with the current-carrying connection island through a first metal bonding piece. According to the fuse, the problem that small fusing energy cannot be configured under large current due to insufficient heat dissipation capability can be effectively solved.

Description

Technical Field

[0001] The present application relates to the technical field of fuses, and in particular to a fuse and a power module. Background Art

[0002] A fuse is a current protector made based on the principle that when the current exceeds the specified value for a period of time, the heat generated by the fuse will melt the fuse and thus disconnect the circuit. It is widely used in high and low voltage power distribution systems and control systems as well as electrical equipment as a short circuit and overcurrent protector.

[0003] At present, fuses mainly adopt natural cooling. In order to ensure the current carrying capacity under rated conditions, it is necessary to increase the cross-sectional area of ​​the fuse core or connect multiple groups in parallel. The fusing energy is much higher than the protected semiconductor device. In the failure mode of busbar short circuit, it is difficult to achieve effective protection, resulting in fault propagation and large losses. Utility Model Content

[0004] In view of this, the embodiments of the present application provide a fuse and a power module, which can effectively solve the problem of being unable to configure a small fuse energy under a large current due to insufficient heat dissipation capacity.

[0005] In a first aspect, an embodiment of the present application provides a fuse, including:

[0006] Thermally conductive substrate;

[0007] An insulating substrate, disposed on the surface of the thermally conductive substrate;

[0008] At least two current-carrying connection islands are attached to the insulating substrate, wherein two adjacent current-carrying connection islands are connected by a conduction mechanism;

[0009] A shell, wherein the insulating substrate and the current-carrying connection island are both arranged in the shell; the shell is filled with arc-extinguishing filling material;

[0010] An electrode is arranged on the surface of the shell; the electrode is connected to the current-carrying connection island through a first metal bonding piece.

[0011] In some embodiments, the current-carrying connection island is attached to the insulating substrate by metal oxidation technology on the surface of the insulating liner.

[0012] In some embodiments, two adjacent current-carrying connection islands are connected via a second metal bonding member, or

[0013] Two adjacent current-carrying connection islands are connected by metal etching, and a narrow path is formed between the two current-carrying connection islands.

[0014] In some embodiments, if two adjacent current-carrying connection islands are connected via the second metal bonding component, the second metal bonding component is connected to the current-carrying connection islands by welding.

[0015] In some embodiments, the electrode includes an input electrode and an output electrode; the input electrode and the output electrode are arranged on the surface of the housing;

[0016] The input electrode and the output electrode are respectively connected to the two current-carrying connection islands arranged at the two ends through the first metal bonding parts.

[0017] In some embodiments, the thermally conductive substrate is made of a thermally conductive metal material; the thermally conductive metal material is copper or aluminum;

[0018] The insulating substrate is made of thermally conductive material; the insulating substrate is made of aluminum oxide or aluminum nitride.

[0019] In some embodiments, the current-carrying connection island is made of metal;

[0020] The current-carrying connection island is made of gold, silver, copper or aluminum.

[0021] In some embodiments, the insulating substrate is welded to the surface of the thermally conductive substrate.

[0022] In some embodiments, the arc-extinguishing filling material is quartz sand, glass fiber, ceramic particles or ruby ​​sand.

[0023] In a second aspect, an embodiment of the present application provides a power module, comprising a heat sink and the above-mentioned fuse; the heat conductive substrate in the fuse is connected to the heat sink via a heat conductive adhesive material.

[0024] The embodiments of the present application have the following beneficial effects: in the present application, the current-carrying connection island, the first metal bonding part, the conduction mechanism, and the insulating substrate form a whole and are welded on the thermally conductive substrate. When in use, since the various components are mostly connected by welding and the thermal conductivity of the materials of each component is good, heat is conducted from top to bottom, and there is very little thermal resistance in the process of heat transfer to the thermally conductive substrate, thereby forming a fuse with high heat dissipation capability. Compared with traditional fuses, it will not have the problem of being unable to configure a small fuse energy under large current due to insufficient heat dissipation capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A first structural schematic diagram of a fuse according to an embodiment of the present application is shown;

[0027] Figure 2 A first structural schematic diagram showing two adjacent current-carrying connection islands connected via a second metal bonding member in an embodiment of the present application is shown;

[0028] FIG3( a ) shows a second structural schematic diagram of a fuse according to an embodiment of the present application;

[0029] FIG3( b ) shows a second structural schematic diagram of an embodiment of the present application corresponding to FIG3( a ) in which two adjacent current-carrying connection islands are connected via a second metal bonding member;

[0030] Figure 4 A first structural schematic diagram showing a narrow path connection formed by two adjacent current-carrying connection islands in an embodiment of the present application through metal etching;

[0031] Figure 5 A second structural schematic diagram showing a narrow connection formed by metal etching between two adjacent current-carrying connection islands in an embodiment of the present application;

[0032] Figure 6 A third structural schematic diagram showing a narrow connection formed by metal etching between two adjacent current-carrying connection islands in an embodiment of the present application;

[0033] FIG. 7( a ) shows a third structural schematic diagram of a fuse according to an embodiment of the present application;

[0034] FIG. 7( b ) shows a fourth structural schematic diagram of a narrow connection formed by metal etching between two adjacent current-carrying connection islands in an embodiment of the present application corresponding to FIG. 7( a );

[0035] Figure 8 A schematic structural diagram of a power module according to an embodiment of the present application is shown.

[0036] Description of main component symbols:

[0037] 100 - thermally conductive substrate; 101 - insulating substrate; 102 - current-carrying connection island; 103 - second metal bonding piece; 104 - arc-extinguishing filling material; 105 - housing; 106 - electrode; 107 - first metal bonding piece; 108 narrow diameter; 109 - heat sink; 110 - thermally conductive adhesive material; 111 - connecting wire. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0039] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0040] Hereinafter, the terms "including", "having" and their cognates used in various embodiments of the present application are intended only to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions and cannot be understood as indicating or implying relative importance.

[0041] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.

[0042] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0043] Since the power semiconductors in the inverter are damaged in a very short time when short circuit occurs, fuses are needed to protect the power semiconductor devices from short circuit. At present, high-power inverters generally use forced air cooling / liquid cooling to improve the system power density. At present, conventional fuses mainly use natural cooling. In order to ensure the current carrying capacity under rated conditions, it is necessary to increase the cross-sectional area of ​​the fuse core or connect multiple groups in parallel. The melting energy (I 2 T) is much higher than the protected semiconductor device. In the failure mode of busbar short circuit, it is difficult to achieve effective protection, resulting in fault spread and large losses. Based on this, the present application proposes a new fuse and power module to avoid the problem that the existing silver fuse has insufficient heat dissipation capacity and cannot be configured with a small I under high current. 2 The problem with the T parameter.

[0044] The fuse is described below in conjunction with some specific embodiments.

[0045] Figure 1 A schematic structural diagram of a fuse according to an embodiment of the present application is shown. Exemplarily, the fuse includes: a heat-conducting substrate 100 , an insulating substrate 101 , a current-carrying connection island 102 , a housing 105 and an electrode 106 .

[0046] Specifically, the thermally conductive substrate 100 is made of a high thermal conductivity metal material, preferably copper and aluminum; the insulating substrate 101 is made of a high insulation and high thermal conductivity material, and the insulating substrate 101 is preferably made of aluminum oxide and aluminum nitride, but can also be made of other high insulation and high thermal conductivity materials; the current-carrying connecting island 102 is made of a metal material, and its metal material includes but is not limited to gold, silver, copper or aluminum. When making the current-carrying connecting island 102, it is preferably made of a metal material with high current carrying capacity, that is, low resistivity. In this way, when in use, the loss generated under the same current is lower and the heat is less. As for the four metal materials of gold, silver, copper or aluminum, silver is better than copper, copper is better than gold, and gold is better than aluminum.

[0047] During manufacturing, the thermally conductive substrate 100 and the insulating substrate 101 are connected together by welding. The insulating substrate 101 is welded to the upper surface or the lower surface of the thermally conductive substrate 100. The connection by welding has low thermal resistance.

[0048] A plurality of current-carrying connection islands 102 are attached to the insulating substrate 101 by metal oxidation technology on the surface of the insulating liner. Specifically, the current-carrying connection islands 102 can be attached to the insulating substrate 101 by, but not limited to, thick film metallization, thin film metallization, and copper metallization technology.

[0049] It should be noted that the current-carrying connection island 102 in the present application is mainly used as a carrier for current to pass through. There is no specific limitation on the shape of the current-carrying connection island 102, and a regular rectangular setting is preferably adopted. The current-carrying connection island 102 in the present application is also used to separate the multi-end narrow path 108 and the second metal bonding part 103.

[0050] A plurality of current-carrying connection islands 102 are arranged in series in sequence, wherein a certain interval is left between two adjacent current-carrying connection islands 102, and two adjacent current-carrying connection islands 102 are connected by a second metal bonding piece 103 and / or metal etching, wherein the second metal bonding piece 103 is made of metal materials such as silver, copper or aluminum. In the present application, by arranging a plurality of current-carrying connection islands 102 at intervals, the electrical distance can be pulled apart in sections when the applied voltage is large, and the risk of electrical breakdown and arcing may exist even if the second metal bonding piece 103 and / or the narrow diameter 108 are fused if only two current-carrying connection islands 102 are arranged. The second metal bonding piece can be a metal bonding wire or a metal bonding tape.

[0051] Furthermore, if Figure 2 As shown, when two adjacent current-carrying connection islands 102 are connected by the second metal bonding component 103, the two ends of the second metal bonding component 103 are respectively welded on the two current-carrying connection islands 102 by hot pressing, ultrasound or thermal ultrasound, and the number of second metal bonding components 103 between two adjacent current-carrying connection islands 102 is at least one. The specific number of second metal bonding components 103 to be set can be set according to the required melting energy. For example, it can be 2, 3, or 10. The number of second metal bonding components between two adjacent current-carrying connection islands is not specifically limited, and it is mainly determined according to the required melting energy and combined with the cross-sectional diameter or area of ​​the second metal bonding component, the material of the bonding wire, etc.

[0052] The second metal bonding parts mentioned in the following description are all described by taking metal bonding wires as examples. It can be understood that if the second metal bonding parts are metal bonding tapes, the same principle applies as for metal bonding wires. If the second metal bonding parts are metal bonding wires, their thickness is usually described by cross-sectional diameter, and if metal bonding tapes are used, their thickness is usually described by cross-sectional area.

[0053] As shown in Figure 3, the fuse uses a copper thermal conductive substrate, the insulating substrate is made of alumina, and contains three current-carrying islands made of copper. The current-carrying islands are spaced 1 to 2 mm apart from each other. The current-carrying islands on the left and right sides are connected to the input electrode and the output electrode respectively through the second metal bonding part. If the required fusing energy is 5400A 2 S, if the fusing energy of a single second metal bonding member is set to 54A 2S, the second metal bonding piece between two adjacent current-carrying connection islands needs to be equipped with 10 aluminum bonding wires with a cross-sectional diameter of 500um (the current carrying capacity of a single aluminum bonding wire with a cross-sectional diameter of 500um is about 23A). In this way, the rated voltage of the fuse can reach up to 1000V, the rated current is about 230A, and the I2T energy is about 5400A. 2 S, can reach the preset requirements. If the aluminum bonding wire is replaced with a copper bonding wire, since the copper bonding wire has a greater current carrying capacity than the aluminum bonding wire, the number of second metal bonding parts between two adjacent current-carrying connection islands can be reduced accordingly. Furthermore, if the cross-sectional diameter of the above aluminum metal bonding part is changed from the original 500um to 1000um, the current carrying capacity of a single aluminum bonding wire will also increase. If 5400A is still required, 2 If the fusing energy of S is increased, the number of second metal bonding parts between two adjacent current-carrying connection islands needs to be reduced accordingly.

[0054] like Figure 4 As shown, when two adjacent current-carrying connection islands 102 are connected by metal etching, a narrow path is formed between the two adjacent current-carrying connection islands 102, and the number of narrow paths 108 between the two adjacent current-carrying connection islands 102 is not specifically limited, and is also set according to the required fusing energy, the width (cross-sectional diameter) of the narrow path, etc. Among them, the narrow path between the two adjacent current-carrying connection islands 102 can be a regular shape, such as Figure 4 Medium rectangle, or irregular shapes, such as Figure 5 The circular narrow diameter and Figure 6 It can be understood that the narrow path 108 can also be other shapes as long as it can connect two current-carrying connection islands, and no further examples are given here.

[0055] As shown in Figures 7(a) and 7(b), schematic diagrams of two current-carrying connection islands connected by a narrow path are shown. The narrow path shown in Figures 7(a) and 7(b) is illustrated by taking a rectangular narrow path as an example. Narrow paths of other shapes are the same as rectangular narrow paths in principle. The fuses in Figures 7(a) and 7(b) also have three current-carrying connection islands, and two adjacent current-carrying connection islands are connected by a narrow path formed by metal etching. The cross-sectional diameter of the narrow path in Figures 7(a) and 7(b) is 500um, and the material of the narrow path is copper. The current carrying capacity of a single narrow path is about 35A, and the rated fuse energy that can be tolerated is 121A. 2 S, 7 (a) and 7 (b) have 7 identical narrow paths between the two current-carrying connection islands, and there are 3 current-carrying connection islands. The fuse can withstand a melting energy of 5929A. 2 S, if the fuse energy we want to set is less than 5929A 2S, it can be achieved by changing the cross-sectional area of ​​the narrow diameter, reducing the number of narrow diameters, or replacing the material of the narrow diameter with other metal materials with small current carrying capacity. If you want the fuse energy to be greater than 5929A 2 S can be achieved by increasing the cross-sectional area of ​​the narrow diameter, increasing the number of narrow diameters, or replacing the material of the narrow diameter with other metal materials with large flow capacity.

[0056] It can be seen from this that the number of current-carrying connection islands and the number and specifications of the conducting mechanisms (second metal bonding parts and / or narrow diameters) in the present application can be set according to actual conditions.

[0057] It is understandable that the conduction mechanisms shown in FIG. 3(a), FIG. 3(b) and FIG. 7(a), FIG. 7(b), and the specifications of the conduction mechanisms are exemplary, and the specific situation needs to be determined according to the actual situation. In addition, it is also understandable that FIG. 3(a), FIG. 3(b) and FIG. 7(a), FIG. 7(b) only illustrate the case where the conduction mechanism is a single second metal bonding member or a single narrow diameter, and the case where the conduction mechanism is a mixed one is also applicable, and the second metal bonding member and the narrow diameter are used at the same time, but the same conduction mechanism needs to be used between the two current-carrying connection islands.

[0058] If the number of the current-carrying connection islands 102 is greater than or equal to 3, all two adjacent current-carrying connection islands 102 can be connected using the same conductive mechanism, that is, both can use the second metal bonding component 103, or both can be connected by metal etching; they can also be connected using different conductive mechanisms, that is, the second metal bonding component 103 and the metal etching method can be used in combination, as long as it can be guaranteed that when in use, when the energy borne exceeds the corresponding fusing energy, the second bonding wire between the current-carrying connection islands 102 and / or the narrow path 108 formed by metal etching can be quickly fused.

[0059] Furthermore, when the fusing energy of the present application is determined, the second metal bonding part 103 and / or the narrow diameter 108 can be adjusted according to the resistance formula R=pL / s; wherein R is the resistance, p is the resistivity of the conductor, L is the length of the conductor, and s is the cross-sectional area of ​​the conductor. For example, reducing the narrow diameter width, reducing the number of second bonding wires, and reducing the width of the second bonding wires will reduce s, increase R, and thus reduce the tolerable fusing energy. Similarly, reducing R can increase the tolerable fusing energy.

[0060] Furthermore, the shell 105 in the present application is stuck on the top of the thermal conductive substrate 100, and the insulating substrate 101 and the current-carrying connection island 102 are sleeved in the shell 105. The surface of the shell 105 is provided with an electrode 106, and the electrode 106 includes an input electrode 106 and an output electrode 106. The input electrode 106 and the output electrode 106 are arranged on the shell 105. The positions of the input electrode 106 and the output electrode 106 on the shell 105 are not limited. Preferably, the input electrode 106 and the output electrode 106 are arranged at both ends of the shell 105, and a hole is opened on the surface of the shell 105 connected to the input electrode 106 and the output electrode 106, so that one end of the first metal bonding part 107 responsible for connecting the current-carrying connection island 102 and the electrode 106 is connected to the electrode 106 through the hole, and the other end is welded to the current-carrying connection island 102. Among them, the first metal bonding part 107 can also use a metal bonding wire or a metal bonding tape.

[0061] Specifically, Figure 1 As shown, the input electrode 106 and the output electrode 106 are respectively connected to the two current-carrying connection islands 102 arranged at the two ends, that is, Figure 1 As shown, Figure 1 The leftmost current-carrying connection island 102 is connected to the left electrode 106, and the rightmost current-carrying connection island is connected to the right electrode 106. It can be understood that although a plurality of current-carrying connection islands 102 are provided, when connecting to the electrode 106, not any current-carrying connection island 102 can be connected, but only the current-carrying connection islands 102 on both sides can be connected to the electrode 106.

[0062] Furthermore, the shell 105 is filled with arc-extinguishing filling material 104, that is, the space formed between the shell 105, the insulating substrate 101 and the current-carrying connection island 102 is filled with arc-extinguishing filling material 104, and the arc-extinguishing filling material 104 can be, but not limited to, quartz sand, glass fiber, ceramic particles, ruby ​​sand, etc. The filling of the arc-extinguishing filling material 104 is mainly to achieve arc energy absorption when the second metal bonding part 103 and / or the narrow diameter 108 formed by metal etching is melted.

[0063] In the present application, the current-carrying connection island 102, the first metal bonding part 107, the conduction mechanism, and the insulating substrate 101 form a whole and are welded on the thermally conductive substrate 100. When in use, since most of the components are connected by welding, and the thermal conductivity of the materials of each component is good, the heat is conducted from top to bottom, and there is very little thermal resistance in the process of heat transfer to the thermally conductive substrate 100, so a large amount of heat will not accumulate inside the fuse. Furthermore, the present application sets up multiple current-carrying connection islands 102, so that when in use, the electrical distance can be pulled apart in sections, which can avoid the risk of electrical breakdown and arcing even if only two current-carrying connection islands 102 can be fused when the current is too large. In addition, in the present application, two adjacent current-carrying connection islands 102 are connected by a second metal bonding piece 103 and / or by metal etching to form a narrow path 108, so that a suitable fusing capacity can be accurately configured by adjusting the number and width of the second metal bonding pieces 103 between the two adjacent current-carrying connection islands 102 and the number, width, thickness, etc. of the narrow paths 108. Furthermore, the fuse of the present application has a simple structure and high quality consistency.

[0064] Figure 8 A schematic diagram of the structure of a power module of an embodiment of the present application is shown. Exemplarily, the power module includes: a heat sink and the above-mentioned fuse; the heat conductive substrate 100 of the fuse is connected to the heat sink through a heat conductive adhesive material 110. The power module can be, but is not limited to, a power switch module packaged in a certain functional combination of a metal oxide semiconductor (power MOS tube), an insulated gate field effect transistor (IGBT), and a fast recovery diode (FRD).

[0065] Specifically, the fuse of the present application is installed on the heat sink 109 (air cooling / liquid cooling) by applying a thermally conductive adhesive material 110 on the bottom surface of the thermally conductive substrate 100 (i.e., the surface connected to the heat sink), and the input / output electrode 106 is connected to the main circuit through a connecting wire 111, wherein the connecting wire can be a copper bus or a cable. The thermally conductive adhesive material 110 includes, but is not limited to, thermally conductive silicone grease, thermally conductive gel, thermally conductive silica gel and other materials.

[0066] The present application is based on semiconductor packaging technology. While ensuring the insulation capacity of the fuse, the heat can be quickly transferred to the heat sink 109 through the thermally conductive substrate 100. Compared with traditional fuses, there will be no situation where a small fusing energy cannot be configured under a large current due to insufficient heat dissipation capacity.

[0067] It can be understood that the options in the above embodiment are also applicable to this embodiment, so they will not be described again here.

[0068] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A fuse, characterized in that: include: Thermally conductive substrate; An insulating substrate, disposed on the surface of the thermally conductive substrate; At least two current-carrying connection islands are attached to the insulating substrate, wherein two adjacent current-carrying connection islands are connected by a conduction mechanism; A shell, wherein the insulating substrate and the current-carrying connection island are both arranged in the shell; the shell is filled with arc-extinguishing filling material; An electrode is arranged on the surface of the shell; the electrode is connected to the current-carrying connection island through a first metal bonding piece.

2. The fuse according to claim 1, characterized in that: The current-carrying connection island is attached to the insulating substrate by metal oxidation technology on the surface of the insulating liner.

3. The fuse according to claim 1 or 2, characterized in that: Two adjacent current-carrying connection islands are connected via a second metal bonding member, or Two adjacent current-carrying connection islands are connected by metal etching, and a narrow path is formed between the two current-carrying connection islands.

4. The fuse according to claim 3, characterized in that: If two adjacent current-carrying connection islands are connected via the second metal bonding component, the second metal bonding component is connected to the current-carrying connection islands by welding.

5. The fuse according to claim 1, characterized in that: The electrodes include an input electrode and an output electrode; the input electrode and the output electrode are arranged on the surface of the shell; The input electrode and the output electrode are respectively connected to the two current-carrying connection islands arranged at the two ends through the first metal bonding parts.

6. The fuse according to claim 1, characterized in that: The thermally conductive substrate is made of a thermally conductive metal material; the thermally conductive metal material is copper or aluminum; The insulating substrate is made of thermally conductive material; the insulating substrate is made of aluminum oxide or aluminum nitride.

7. The fuse according to claim 6, characterized in that: The current-carrying connection island is made of metal material; The current-carrying connection island is made of gold, silver, copper or aluminum.

8. The fuse according to claim 1, characterized in that: The insulating substrate is welded on the surface of the thermally conductive substrate.

9. The fuse according to claim 1, characterized in that: The arc extinguishing filling material is quartz sand, glass fiber, ceramic particles or ruby ​​sand.

10. A power module, characterized in that: It comprises a heat sink and the fuse according to any one of claims 1 to 9; the heat-conducting substrate in the fuse is connected to the heat sink via a heat-conducting adhesive material.

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