Semiconductor assembly having at least one semiconductor element

Abstract

The invention relates to a semiconductor component (2), in particular a power semiconductor component for a converter (64), having at least one semiconductor element (4), in order to improve the recyclability of the semiconductor component (2), it is proposed that the semiconductor element (4) is arranged in a housing (6), the housing (6) being at least partially filled with a potting compound (30), the potting compound can be melted by means of a heating process and is in direct contact with the semiconductor element (4).

Description

Field of the Invention

[0001] The present invention relates to a semiconductor component, in particular a power semiconductor component for a converter, having at least one semiconductor element.

[0002] Furthermore, the present invention relates to a converter having at least one such semiconductor component.

[0003] Furthermore, the present invention relates to a method for recycling or repairing a semiconductor component having semiconductor elements. Background Art

[0004] Such semiconductor components are used, for example, in converters. A converter can be understood, for example, as a rectifier, an inverter, a frequency converter or a DC voltage converter. Generally, such a semiconductor component includes a housing in which at least one semiconductor element is arranged. Such a semiconductor element can in particular be a transistor. Inside the housing, there is usually a casting made of a thermosetting plastic, in particular a silicone resin casting or an epoxy resin casting, for protecting at least one semiconductor element.

[0005] Such semiconductor components are used, for example, in converters. A converter can be understood, for example, as a rectifier, an inverter, a frequency converter or a DC voltage converter. Generally, such a semiconductor component includes a housing in which at least one semiconductor element is arranged. Such a semiconductor element can in particular be a transistor. Inside the housing, there is usually a soft casting, in particular a silicone resin casting, for protecting at least one semiconductor element.

[0006] The published document WO 2022 / 033745 A1 describes a power module having at least one power unit, the power unit including at least one power semiconductor and a substrate, wherein at least one power unit is at least partially surrounded by a housing. The housing is filled with a soft casting, in particular with a silicone resin casting.

[0007] Environmental and sustainability aspects have also become increasingly important in the development of electronics. In particular, improved recyclability has received attention. Recyclability and repair costs are improved, for example, by eliminating material-locking connections that can be established, for example, by soldering, sintering or welding.

[0008] The published document EP 3 926 670 A1 describes a power semiconductor module having at least one power semiconductor element. In order to reduce the structural space required for the power semiconductor module and increase its service life, it is proposed that at least one power semiconductor element be in an electrically insulating and thermally conductive connection with a cooling element through a dielectric material layer, wherein the dielectric material layer lies flat on the surface of the cooling element and is force-fittingly connected to the cooling element by a first force acting orthogonally to the surface of the cooling element.

[0009] The published document WO 2018 / 046165 A1 describes a power module having semiconductor structural elements to be contacted on an upper side and a lower side, wherein the semiconductor structural elements are electrically contacted on the upper side by means of a lead frame matrix with a pressing force. Summary of the Invention

[0010] For example, in a recycling process, potting parts made of thermosetting plastics are very difficult to remove. Against this background, the object of the present invention is to improve the recyclability of semiconductor components.

[0011] This object is solved according to the invention by a semiconductor component, in particular a power semiconductor component for a converter, having at least one semiconductor element, wherein the semiconductor element is arranged in a housing, wherein the housing is at least partially filled with a potting compound which can be melted via a heating process and which is in direct contact with the semiconductor element.

[0012] Furthermore, according to the invention, this object is solved by a converter having at least one such semiconductor component.

[0013] Furthermore, this object is solved according to the invention by a method for recycling or repairing a semiconductor component having a semiconductor element, wherein the semiconductor element is arranged in a housing, wherein the housing is at least partially filled with a potting compound which can be melted via a heating process and which is in direct contact with the semiconductor element, the method comprising the steps of: liquefying the potting compound by heating, discharging the liquefied potting compound from the housing and removing the semiconductor element from the housing.

[0014] Furthermore, this object is solved according to the invention by a method for recycling or repairing a semiconductor component having a semiconductor element, wherein the semiconductor element is arranged in a housing, wherein the housing is at least partially filled with a potting compound which can be melted via a heating process and which is in direct contact with the semiconductor element, the method comprising the steps of: evaporating the potting compound by heating, discharging the gaseous potting compound from the housing and removing the semiconductor element from the housing.

[0015] The advantages and preferred designs listed below for the semiconductor component can be reasonably transferred to the converter, the manufacturing method and the application.

[0016] The present invention is based on the following consideration, that is, to improve the recyclability of semiconductor components by replacing the commonly used soft potting made of thermosetting plastics with a potting compound that can be melted by means of a heating process. The housing of the semiconductor component is at least partially filled with the meltable potting compound such that the semiconductor element is in direct contact with the meltable potting compound, and at least one semiconductor element is arranged in the housing. In particular, the semiconductor element is at least partially surrounded by the meltable potting compound. The meltable potting compound is implemented to be electrically insulating and can contain, for example, thermoplastics or paraffin. In particular, the meltable potting compound has a breakdown strength of 2 kV / mm at room temperature. For example, high melting point paraffin or other waxes, especially those with a melting point above 100 °C, can be considered. The potting compound can be removed in a liquefied or gaseous state. The potting compound is heated, for example, by an electrical heating device, especially by means of a heating plate, on a metal base plate or a cooling body. Compared with the commonly used thermosetting plastics, the meltable potting compound can be removed significantly more easily and substantially residue-free. By means of this meltable potting compound, simple disassembly for repair or recycling can be achieved.

[0017] Another embodiment provides that a circuit carrier is arranged in the housing, wherein the semiconductor element is in force-fitting connection with the circuit carrier, in particular by means of at least one press contact. The circuit carrier can in particular be implemented as a substrate, especially as a DCB (direct copper bonding) substrate. Such a press contact can in particular be implemented as a bus bar also known as a bus bar. Alternatively, springs, screws and / or clamps can be used for the force-fitting connection of the semiconductor element. This positive connection of the semiconductor element is detachable and can be removed simply and substantially residue-free during disassembly for repair or recycling, especially in combination with the filling made of the meltable potting compound.

[0018] Another embodiment provides that the housing has a discharge opening for removing the meltable potting compound. The discharge opening is arranged, for example, in the housing frame or the housing cover and enables the discharge of the liquefied or gaseous potting compound. The discharge opening can in particular additionally be used for filling the housing with the meltable potting compound. The discharge opening can also be implemented as a rated fracture location or as a marking for introducing an opening in the housing. In particular, the discharge can be achieved without removing the cover through the discharge opening, and more uniform heating of the potting compound is achieved through the cover, such that the removal of the potting compound substantially residue-free is additionally simplified.

[0019] Another embodiment provides that the discharge opening is sealed in a fluid-tight and detachable manner by a first sealing element during the operation of the semiconductor component. The first sealing element is implemented as a sealing plug, for example. Such a sealing plug enables the simple removal of the potting compound and reliably and inexpensively ensures the tightness of the housing.

[0020] Further embodiments provide that the housing has a pressure compensation opening which is sealed in a fluid-tight and detachable manner by means of a second sealing element during operation of the semiconductor component. The pressure compensation opening can also be embodied as a rated breaking point or as a marking for introducing an opening in the housing. The second sealing element is embodied, for example, as a sealing plug. In particular, the discharge opening and the pressure compensation opening are arranged such that at least 60% of the enclosed volume can be located between the openings. The air flow passing through the pressure compensation opening compensates the pressure in the housing, so that the potting compound can be removed from the housing substantially residue-free.

[0021] Further embodiments provide that the housing is at least partially made of a fusible material which has a higher melting temperature than the fusible potting compound. In this way, it is ensured that the housing does not liquefy during heating and discharging of the potting compound.

[0022] Further embodiments provide that the semiconductor component includes an electrical heating device which is at least partially arranged inside the housing. For example, heating conductors are arranged in the region of the inner surface of the housing frame or the housing cover. By means of this heating device, the required energy input is reduced and accidental detachment of components inside the housing is prevented, especially compared to heating by means of a cooling body or a bottom plate.

[0023] Further embodiments provide that the electrical heating device includes a heating coil which is at least partially connected to the housing. The heating coil can be connected to the inner surface of the housing frame or the housing cover. The energization of the heating coil can be carried out in a contactless manner, in particular in a transformer-like manner. Such a heating device enables the potting compound to be heated simply and quickly. Description of the Drawings

[0024] The present invention will be described and explained in more detail below with the aid of the embodiments shown in the drawings.

[0025] Shown:

[0026] Figure 1 A schematic cross-sectional view showing a first embodiment of a semiconductor component,

[0027] Figure 2 The recirculation of a first embodiment of a semiconductor component is shown in a schematic cross-sectional view,

[0028] Figure 3 A schematic cross-sectional view showing a second embodiment of a semiconductor component,

[0029] Figure 4 A schematic cross-sectional view showing a third embodiment of a semiconductor component,

[0030] Figure 5Schematic cross-sectional view showing a fourth embodiment of a semiconductor component,

[0031] Figure 6 Schematic view showing a converter.

[0032] The embodiments described below are preferred embodiments of the present invention. In the embodiments, the described components of the embodiments are respectively individual features of the present invention that can be regarded as independent of each other. These features also improve the present invention independently of each other and can therefore be regarded as components of the present invention individually or in combinations different from the combinations shown. In addition, the described embodiments can also be supplemented by additional features of the features already described in the present invention.

[0033] The same reference numerals have the same meaning in different figures. Detailed Description of the Invention

[0034] Figure 1 Schematic cross-sectional view showing a first embodiment of a semiconductor component 2 having a semiconductor element 4, which semiconductor element is arranged in a closed housing 6. For example, the semiconductor element 4 is implemented as a vertical transistor, in particular as an IGBT or a vertical SiC-MOSFET. The housing 6 includes a metallic cooling body 8, a housing frame 10 having a plurality of pins 12, and a housing cover 14. The housing frame 10 and the housing cover 14 are made of plastic, for example, and these pins 12 are cast or pressed into the housing frame 10. The cooling body 8 acting as a bottom plate is made of copper, aluminum or an alloy thereof, for example. The circuit carrier 16 is connected to the cooling body 8 in a planar manner. Exemplarily, the circuit carrier 16 includes a dielectric material layer 18 and a metallization 20. The dielectric material layer particularly includes alumina, aluminum nitride or an organic electrically insulating and thermally conductive material, and the metallization includes copper, gold, molybdenum, silver or an alloy thereof, for example. The dielectric material layer 18 can be extruded together with the cooling body or adhesively connected thereto. Alternatively, the circuit carrier 16 can be implemented as a substrate, in particular as a DGB (direct copper bonding) substrate, and the substrate is soldered to the cooling body 8, for example.

[0035] The semiconductor component 4 has a first power contact 22, in particular a collector contact, and on the opposite side a second power contact 24, in particular an emitter contact, and a control contact 26, in particular a gate contact. The first power contact 22 of the semiconductor component 4 is, for example, adhesively connected to the metallization 20 of the circuit carrier 16. The adhesively bonded connection of the semiconductor component 4 to the circuit carrier 16 can in particular be produced by soldering and / or sintering. The second power contact 24 and the control contact 26, which are arranged on the side of the semiconductor component 4 facing away from the circuit carrier 16, are each connected to the metallization 20 of the circuit carrier 16 by a wiring mechanism 28, wherein the metallization 20 is connected to the pin 12 of the housing 6. In this way, the contacts 22, 24, 26 of the semiconductor component 4 are led out of the housing 6 and can be conductively contacted from the outside via the pins 12. The wiring mechanism 28 is, for example, embodied as a bonding wire or a bonding strip, which is in particular welded by ultrasonic wire bonding.

[0036] The housing 6 is filled with a potting compound 30, which can be melted via a heating process and which is in direct contact with the semiconductor component 4 and partially surrounds the semiconductor component. The potting compound 30 can in particular contain a thermoplastic or paraffin. In particular, high-melting paraffins or other waxes with a melting point above 100 °C can be considered, such that the potting compound is solid at room temperature. The potting compound 30 can contain fillers such as ceramic particles. The potting compound 30 can be liquefied or evaporated for removal.

[0037] The housing 6 can be at least partially made of a fusible material, which has a higher melting temperature than the fusible potting compound 30, in order to prevent the housing from also being liquefied when the fusible potting compound 30 is heated. In order to remove the fusible potting compound 30, the housing has a discharge opening 32, which is sealed in a fluid-tight and detachable manner during operation of the semiconductor module 2 by a first closing element 34. The first closing element 34 is, for example, embodied as a sealing plug. In addition, the housing 6 has a pressure compensation opening 36, which is sealed in a fluid-tight and detachable manner during operation of the semiconductor module 2 by a second closing element 38. The openings 32, 36 are arranged such that at least 60 % of the enclosed volume can be located between the openings 32, 36. The openings 32, 36 can also be embodied as predetermined breaking points or as markings for inserting openings in the housing 6.

[0038] Figure 2 A recycling of a first embodiment of the semiconductor module 2 is shown in a schematic cross section, wherein the liquefied potting compound 30 is discharged through the discharge opening 32. For this purpose, the first closing element 34 is removed from the discharge opening 32 and the second closing element 38 is removed from the pressure compensation opening 36. The semiconductor module 2 as inFigure 1 is implemented as shown. The potting compound 30 is liquefied by heating with the aid of an electric heating device, for example by means of a hot plate. Alternatively, the potting compound 30 can be converted into a gaseous state by heating for removal.

[0039] The liquefied potting compound 30 is discharged through the discharge opening 32 into the collecting container 42. For example, the housing 6 is inclined at an angle α. The angle α can be in the range from 10° to 90° and can change several times in particular during the discharge. Additionally or alternatively, the collecting container 42 can include a suction device for sucking the potting compound 30. Separately collecting the potting compound 30 improves environmental friendliness or sustainability. The air flow 43 flowing through the pressure compensation opening 36 compensates the pressure in the housing 6 so that the potting compound 30 can be removed from the housing 6 in particular without residue. Alternatively, in the case of a wire-bonded circuit, pressure compensation can be carried out by removing the housing cover 14 without a pressure compensation opening 36, wherein the potting compound 30 is heated more uniformly by the housing cover 14.

[0040] In a further step, the housing cover 14 is opened and the semiconductor element 4 is removed. Additionally, the circuit carrier 16, in particular the DGB substrate, can be removed. In this way, the components for further use are cleanly separated.

[0041] The liquefied potting compound 30 can also be discharged through the discharge opening 32 for repair, wherein the housing cover 14 is opened to remove at least one defective semiconductor element 4. In a further step, at least the defective semiconductor element 4 is replaced. In particular, it is possible to remove the circuit carrier 16 having at least one defective semiconductor element 4, and the defective semiconductor element replaces the removed component in a further step.

[0042] Figure 3 Schematic cross-sectional view showing a second embodiment of the semiconductor assembly 2, wherein the semiconductor element 4 is force-fittingly connected to the circuit carrier 16 by means of a first pressure contact 44. The first pressure contact 44 establishes an electrical contact of the second power contact 24 of the semiconductor element 4 in addition to mechanical fixation.

[0043] The first metal contact element 46 is connected to the second power contact portion 24 of the semiconductor element 4 and serves as a buffer layer that distributes the force F from the pressure contact portion 44, thereby preventing pressure peaks from being introduced into the sensitive semiconductor element 4. The first metal contact element 46 can in particular be implemented as a metal sheet containing copper and / or molybdenum and has a thickness in the range of 25 μm to 250 μm. The connection of the first metal contact element 46 to the semiconductor element 4 can be made by material bonding, for example by soldering or sintering. Alternatively, the first metal contact element 46 can be sprayed, in particular in the form of copper particles and / or molybdenum particles, by means of a thermal spraying method. An optional second metal contact element 48 is arranged between the first power contact portion 22 and the circuit carrier 16, and the second metal contact element can be implemented as a metal sheet containing in particular copper and / or molybdenum.

[0044] The second pressure contact portion 50 and the third pressure contact portion 52 are force-fittingly connected to the metallization 20 of the circuit carrier 16 for electrically contacting the first power contact portion 22 or the control contact portion 26, wherein the control contact portion 26 is connected to the metallization 20 by means of at least one wiring mechanism 28. The circuit carrier 16 is pressed onto the cooling body 8 by the pressure contact portions 44, 50, 52 and is thereby force-fittingly connected thereto.

[0045] The pressure contact portions 44, 50, 52 are implemented as busbars, which are also referred to as bus bars. For example, the busbars are made of copper or a copper alloy. Additionally or alternatively, the pressure contact portions 44, 50, 52 can have springs, screws or clamps. The busbars are guided out of the housing 6 via the sealing element 54, so that the housing 6 is sealed in a fluid-tight manner. A plurality of first pressure contact portions 44 are arranged in particular equidistantly in a square or rectangle on the metal contact element 46 (for example 2x2, 2x3, 3x4 or 4x4), which can improve the mechanical fixation of the semiconductor element 4, make the pressure distribution more uniform, and achieve a low-resistance electrical contact. Figure 3 Another embodiment of the semiconductor assembly 2 in Figure 1 corresponds to the embodiment in Figure 2 Recycling is carried out as shown in

[0046] Figure 4Schematic cross-sectional view showing a third embodiment of semiconductor component 2, wherein an electric heating device 56 is arranged in a housing 6. The electric heating device 56 has a heating coil 58 which is exemplarily connected to the housing cover 14. For example, the heating coil 58 and the plastic housing cover 14 are manufactured together by means of the MID (molded interconnect device) method. The heating device can include an electrical contact 60 for connection to a current source 62, wherein the electrical contact 60 is arranged to extend through the housing cover 14. Alternatively, the heating coil 58 can be energized contactlessly via a transformer. Figure 4 A further embodiment of the semiconductor component 2 in Figure 1 corresponds to the embodiment in Figure 3 As shown in

[0047] Figure 5 Schematic cross-sectional view showing a fourth embodiment of semiconductor component 2, wherein the electric heating device 56 includes at least one electrically insulated heating wire 62 which is arranged to extend through the housing 6. The at least one electrically insulated heating wire 62 is potted with a potting compound 30 and can directly heat the potting compound. Figure 5 A further embodiment of the semiconductor component 2 in Figure 4 corresponds to the embodiment in

[0048] Figure 6 Schematic view showing a converter 64 including the semiconductor component 2. The converter 64 can include more than one semiconductor component 2.

[0049] In summary, the present invention relates to a semiconductor component 2, in particular a power semiconductor component for a converter 64, which has at least one semiconductor element 4. In order to improve the recyclability of the semiconductor component 2, it is proposed to arrange the semiconductor element 4 in a housing 6, wherein the housing 6 is at least partially filled with a potting compound 30 which can be melted via a heating process and which is in direct contact with the semiconductor element 4.

Claims

1. A semiconductor component (2), in particular a power semiconductor component for a converter (64), having at least one semiconductor element (4), wherein, The semiconductor component (4) is arranged in a housing (6), wherein the housing (6) is at least partially filled with a potting compound (30) which can be melted via a heating process and which is in direct contact with the semiconductor component (4).

2. The semiconductor component (2) according to claim 1, wherein, A circuit carrier (16) is arranged in the housing (6), wherein the semiconductor component (4) is force-fittingly connected to the circuit carrier (16) in particular by means of at least one pressure contact (44, 50, 52).

3. The semiconductor component (2) according to any one of claims 1 or 2, wherein, The housing (6) has a discharge opening (32) for removing the meltable potting compound (30).

4. The semiconductor component (2) according to claim 3, wherein, The discharge opening (32) is fluid-tightly and removably closed by a first closing element (34) during operation of the semiconductor module (2).

5. The semiconductor component (2) according to any one of claims 3 or 4, wherein, The housing (6) has a pressure compensation opening (36) which is fluid-tightly and removably closed by a second closing element (38) during operation of the semiconductor module (2).

6. The semiconductor component (2) according to any one of the preceding claims, wherein, The housing (6) is at least partially made of a meltable material which has a higher melting temperature than the meltable potting compound (30).

7. The semiconductor module (2) according to any one of the preceding claims, comprising an electrical heating device (56) which is at least partially arranged within the housing (6).

8. The semiconductor component (2) according to claim 7, wherein, The electrical heating device (56) has a heating coil (58) which is at least partially connected to the housing (6).

9. A converter (64) having at least one semiconductor module (2) according to any one of the preceding claims.

10. A method for recycling or repairing a semiconductor module (2) having a semiconductor component (4), Among them, wherein the semiconductor component (4) is arranged in a housing (6), wherein the housing (6) is at least partially filled with a potting compound (30) which can be melted via a heating process and which is in direct contact with the semiconductor component (4), the method comprising the following steps: - liquefying the potting compound (30) by heating, - discharging the liquefied potting compound (30) from the housing (6), and - removing the semiconductor component (4) from the housing (60).

11. The method according to claim 10, Among them, a circuit carrier (16) is arranged in the housing (6), wherein the semiconductor component (4) is force-fittingly connected to the circuit carrier (16) in particular by means of at least one pressure contact (44, 50, 52), wherein the removal of the semiconductor component (4) from the housing (6) includes disassembling the pressure contacts (44, 50, 52).

12. The method according to any one of claims 10 or 11, Among them, the housing (6) has a discharge opening (32) for removing the meltable potting compound (30), Wherein, during operation of the semiconductor component (2), the discharge opening (32) is sealed in a fluid-tight and detachable manner by a first sealing element (34). Wherein, before discharging the liquefied potting compound (30), the discharge opening (32) is opened by removing the first sealing element (32). Wherein, the liquefied potting compound (30) is discharged via the discharge opening (32).

13. The method according to claim 12, Among them, The housing (6) has a pressure compensation opening (36), which is sealed in a fluid-tight and detachable manner by a second sealing element (38) during operation of the semiconductor component (2). Wherein, before discharging the liquefied potting compound (30), the pressure compensation opening (36) is opened by removing the second sealing element (38). Wherein, when the liquefied potting compound (30) is discharged via the discharge opening (32), pressure compensation is carried out via the pressure compensation opening (36).

14. The method according to any one of claims 10 to 13, Among them, The semiconductor component (2) includes an electric heating device (56), which is at least partially arranged inside the housing (6). Wherein, heating is at least partially carried out via the electric heating device (56).

15. A method for recycling or repairing a semiconductor component (2) having a semiconductor element (4), Among them, The semiconductor element (4) is arranged in a housing (6). Wherein, the housing (6) is at least partially filled with a potting compound (30), which can be melted via a heating process and which is in direct contact with the semiconductor element (4), the method comprising the following steps: - Evaporating the potting compound (30) by heating, - Discharging the gaseous potting compound (30) from the housing (6), and - Removing the semiconductor element (4) from the housing (6).

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