Housing, power module, and electric device

Abstract

The invention relates to a housing (1) for a power module (30). The housing (1) has a substantially rectangular design in plan view and comprises an outer housing frame (2), a connection region (3), and an inner housing frame (4), wherein the inner housing frame (4) is designed to receive and at least partly house an installation surface (5) for at least one electric component (26) of the power module (30), and the outer housing frame (2) is arranged outside of the inner housing frame (4) and is connected to the inner housing frame (4) via the connection region (3). The invention additionally relates to a power module (30) having such a housing (1) and an installation surface (5) for at least one electric component (26), said installation surface (5) being received and at least partly housed by the inner housing frame (4). The invention additionally relates to an electric device (32), in particular a converter, comprising at least one such housing (1) and / or at least one such power module (30), preferably at least three such power modules (30). In order to provide an improved housing (1), an improved power module (30), or an improved electric device (32) in particular, the invention proposes that the connection region (3) in the region of the respective short side (6) has a respective stepped connection region (7) which is arranged below the upper edge (8) of the outer housing frame (2) in the region of the respective short side (6) in plan view.

Description

[0001] Description

[0002] Housing, power module and electrical device

[0003] The invention relates to a housing for a power module, wherein the housing is substantially rectangular in plan view and has an outer housing frame, a connecting region and an inner housing frame, wherein the inner housing frame is designed to receive and at least partially enclose a mounting surface for at least one electrical component of the power module and wherein the outer housing frame is arranged outside the inner housing frame and is connected to the inner housing frame via the connecting region.

[0004] Furthermore, the invention relates to a power module comprising such a housing and a mounting surface for at least one electrical component, wherein the mounting surface is received by the inner housing frame and at least partially enclosed.

[0005] Finally, the invention relates to an electrical device, in particular a converter, comprising at least one such housing and / or at least one such power module, preferably at least three such power modules.

[0006] Such devices are used in a wide variety of applications in power electronics. The housings, often called terminal housings, for power modules serve to create a secure and permanent connection between power semiconductor chips and a printed circuit board. The connection between the semiconductor chips and the terminals is often made using bonding wires or ribbons with a diameter of approximately 75 pm to 600 pm, or a width of 0.5 mm to 3 mm. For the sake of simplicity, the terms bonding wires and wire bonding are used in the following text. The wires can be attached to both the chip and the terminals using (heavy wire) ultrasonic bonding or ultrasonic welding, i.e. in particular using an ultrasonic joining technique. The ultrasonic frequency is in the range of 10 kHz to 150 kHz, depending on the bonding machine and bonding head used, and is generally not changeable.

[0007] Ultrasonic frequencies can be used to excite the natural frequencies of the terminal housing during the bonding process or during joining using ultrasonic bonding technology. These natural frequencies are defined by the size, structures, and material properties, such as stiffness, of the housing. If the vibration is insufficiently damped, a resonance effect will cause the bond to oscillate. In this case, the bond connection may be insufficiently strong, so that the bond wire can later become loose at any time during operation, or in extreme cases, the wire may even fall off after the bonding process.

[0008] This problem may occur more frequently under the following conditions:

[0009] • The pins are firmly connected to the terminal housing, e.g. by overmolding, in contrast to plugged pins, which are partly still glued.

[0010] • The terminal housing is made of a very rigid plastic, such as polyphenylene sulfide (PPS). This high rigidity may be due, for example, to a high glass fiber content, which is intended to ensure greater heat resistance. This requirement arises from the increase in the permissible maximum chip temperature from the original 150°C to 175°C or more in recent years.

[0011] • The screw connection points of the terminal housing, which are also the holding points during the bonding process, are not located at the corners and outside the alignment lines of the pins.

[0012] • The housing geometry is asymmetrical with respect to the pins on the long and short sides. • To insert the pins into the tool before overmolding, space is required in the tool, which limits design freedom.

[0013] • In order to hold the pins securely during the injection process, clamping mechanisms must be provided in the tool, which also restrict the design freedom.

[0014] • To ensure that the terminal housing is ejected safely after the injection molding process, a sufficient number of ejectors must be provided, which imposes further design restrictions.

[0015] The excitation of resonances during the bonding process is a well-known problem in wire bonding. The problem is particularly aggravated when using thicker wires with diameters of 400 pm to 500 pm, as higher contact forces and ultrasonic power levels are applied, resulting in stronger excitation.

[0016] An object of the invention is to provide an improved housing, a corresponding power module and a corresponding electrical device, which in particular overcomes the disadvantages explained above and, for example, facilitates a secure and permanent connection of bonded electrical connections within the power module.

[0017] A solution to the problem is provided by a housing of the type mentioned at the outset in that the connecting area in the area of ​​the respective short side has a stepped connecting area which, when viewed from above, is arranged below the upper edge of the outer housing frame in the area of ​​the respective short side.

[0018] A further solution to the problem is provided by a power module of the type mentioned at the outset in that the power module has the proposed housing and a mounting surface for at least one electrical component, wherein the mounting surface is received and at least partially enclosed by the inner housing frame. An additional solution to the problem is provided by an electrical device of the type mentioned at the outset in that the electrical device has the proposed housing and / or the proposed power module, preferably at least three of the proposed power modules.

[0019] The mounting surface can be designed, for example, as a metal plate, a flat surface of a heat sink or a substrate. The substrate can be, for example, a DGB (Direct Copper Bonded) substrate or an AMB (Active Metal Brazing) substrate. In some examples, a printed circuit board (PCB) can also be used as the substrate. Furthermore, the substrate or, in general, the mounting surface can also be designed in two or more pieces. The respective electrical component can be mounted directly on the mounting surface. A bottomless housing or power module is also conceivable.

[0020] When viewed from above, the housing is essentially rectangular. For example, the mounting surface or the substrate can also be designed as a flat plate or as a flat cuboid. Thus, when viewed from above, the housing or the mounting surface has two opposing short sides and two opposing long sides. If the housing or the mounting surface is designed in two pieces or multiple pieces, the housing or mounting surface formed from the two or more mounting surfaces or substrate pieces can, for example, also have a substantially rectangular floor plan when viewed from above. In particular, the top view of the housing or the mounting surface is viewed from the top side of the housing or the mounting surface, with electrical components, in particular power semiconductors or transistors, for example, being arranged on the top side of the mounting surface.

[0021] To accommodate the mounting surface, the housing has, in particular, the inner housing frame, which is connected to the outer housing frame via the connecting area. For example, the inner housing frame, the connecting area, and the outer housing frame, or at least two of these elements, can be constructed in one piece.

[0022] The connection area is present at least in the area of ​​the two short sides explained above and can also be present in the area of ​​the two long sides explained above. In some examples, however, the housing does not have a separate connection area in the area of ​​the long side. In the area of ​​the two short sides, the connection area each has a stepped connection area. The outer housing frame also has an upper edge in the area of ​​the two short sides when viewed from above. This means that if the mounting surface spans an x-y plane, the outer housing frame extends in the area of ​​the respective short side, particularly in the z-direction, with the top side of the mounting surface pointing in the positive z-direction and the underside of the mounting surface pointing in the negative z-direction.The upper edge of the outer housing frame in the area of ​​the respective short side then corresponds to the uppermost point of the outer housing frame in the positive z-direction and analogously the lower edge of the outer housing frame in the area of ​​the respective short side corresponds to the lowest point of the outer housing frame in the negative z-direction.

[0023] This respective offset connection area is located below the upper edge of the outer housing frame. In other words, the outer housing frame projects beyond the respective offset connection area in the positive z-direction in the area of ​​the respective short side.

[0024] In particular, thanks to the offset connection area described above, any swinging of the housing during bonding or connecting of components of the power module using an ultrasonic joining technique can be reduced or prevented, thus facilitating a secure and permanent connection of bonded electrical connections within the power module.

[0025] In an advantageous embodiment of the invention, the offset connecting region is arranged in a plan view above the lower edge of the outer housing frame in the region of the respective short side.

[0026] The respective offset connection area is thus located above the lower edge of the outer housing frame. In other words, the outer housing frame projects beyond the respective offset connection area in the area of ​​the respective short side, even in the negative z-direction.

[0027] This design of the offset connection area or the housing also helps to reduce or prevent the housing from swinging open during bonding or connecting components of the power module using an ultrasonic joining technique, so that a secure and permanent connection of bonded electrical connections within the power module is facilitated.

[0028] In a further advantageous embodiment of the invention, the housing has a plurality of connection pins, wherein the respective connection pin has at its lower end a respective connection pin contact surface, via which the respective connection pin can be connected to the mounting surface by means of a bonding wire and by bonding, and wherein the offset connection region is arranged perpendicular to the plane of the mounting surface predominantly in a height range around the height of the respective connection pin contact surface.

[0029] For example, the housing can have cutouts in the area of ​​the long sides, wherein the cutouts can be cuboidal or cylindrical. A connection pin can be attached in one of the cutouts. Alternatively, the respective connection pin can also be overmolded, so that the housing does not have to have a cutout to accommodate the respective connection pin. At its lower end, the respective connection pin has a connection pin contact surface. In particular by means of a bonding wire, the respective connection pin can be electrically connected to the mounting surface, for which purpose bonding or an ultrasonic connection technology can be used in particular.

[0030] The respective connection pin contact surface is arranged at a specific height when viewed perpendicular to the plane of the mounting surface, with the offset connection region being predominantly arranged in a height range around this height. In the example explained above, in which the mounting surface spans an xy plane, the respective connection pin contact surface is therefore at a height which corresponds to a specific value in the z direction, and the offset connection region is predominantly located in a height range in the z direction which is arranged around the stated height or the specific value in the z direction.

[0031] In a further advantageous embodiment of the invention, the height range is ± 20 mm, in particular ± 10 mm or ± 5 mm, and / or the height range extends over three quarters, in particular half or one quarter, of the extent of the outer housing frame in a direction perpendicular to the plane of the mounting surface.

[0032] In the example explained above, in which the mounting surface spans an xy plane, the height range extends in the z direction. The direction perpendicular to the plane of the mounting surface therefore corresponds to the z direction. The height range can, for example, extend by ± 10 mm by the height in the z direction of the respective connection pin contact surface. In particular, the height range extends over a quarter of the extension of the outer housing frame in the z direction, whereby this refers in particular to the extension of the outer housing frame in the area of ​​the respective short side. Particularly good results can be achieved with a height range of ± 10 mm or a quarter of the extension of the outer housing frame in the z direction.

[0033] In a further advantageous embodiment of the invention, the housing is designed, in a plan view, below the connecting region and the inner housing frame for receiving a base plate or a cooling element, wherein the respective offset connecting region has a support section which touches the received base plate or the received heat sink or is connected to it.

[0034] The base plate is thus arranged under the mounting surface, i.e., from bottom to top or from the negative z-direction to the positive z-direction, the base plate is arranged first, then the mounting surface and then optionally the electrical components arranged on the mounting surface, in particular power semiconductors.

[0035] The base plate can be accommodated by the housing, for example by the inner housing frame supporting the base plate or being connected to the base plate. To accommodate the base plate in the housing, the respective offset connection area has a support section which touches the accommodated base plate or is connected to it (e.g. using adhesive). The offset connection area can therefore at least partially fix or hold the base plate via the support section. In addition to supporting the base plate, the support section has the advantage that force can be introduced from the offset connection area into the base plate, which can possibly dampen vibrations that occur during bonding. The respective support section can therefore also help to facilitate a secure and permanent connection of bonded electrical connections within the power module.The base plate can be designed as a heat sink, which for example has cooling fins or pins or includes heat pipes.

[0036] In a further advantageous embodiment of the invention, the respective support section is arranged at an end of the offset connecting region which faces the outer housing frame.

[0037] Particularly good results with regard to the damping of vibrations occurring during bonding can be achieved by arranging the respective support section at the end of the offset connection area facing the outer housing frame.

[0038] In a further advantageous embodiment of the invention, the respective offset connecting region from the inner housing frame to the outer housing frame is inclined at least in sections in a downward or upward direction when viewed from above onto the mounting surface.

[0039] The inclination means, in particular, that the respective offset connection area rises from the inner housing frame to the outer housing frame either in the positive z-direction or falls in the negative z-direction. The inclination is therefore particularly present in the positive or negative z-direction, starting from the above-mentioned xy-plane, which is spanned by the mounting surface.

[0040] The at least partially inclined design of the respective offset connection area can in particular lead to a stiffening of the housing, which can dampen vibrations occurring during bonding or, for example, can shift them to higher resonance frequencies which are not critical for the bonding process or the ultrasonic connection process.

[0041] In some examples, the respective offset connection area has a continuous downward or upward slope. It is also conceivable that the respective offset connection area has sections that rise and fall from the inner housing frame to the outer housing frame.

[0042] Particularly good results with regard to the damping of vibrations occurring during bonding or joining using an ultrasonic joining technique can be achieved if the respective offset joining area is inclined downwards from the inner housing frame to the outer housing frame, i.e., it is lowered in the negative z-direction.

[0043] In a further advantageous embodiment of the invention, the inclination of the respective offset connection region is between 3 ° and 30 °, preferably between 5 ° and 15 °, in particular approximately 9 °.

[0044] Particularly good results with regard to the damping of vibrations occurring during bonding can be achieved if the respective offset connection area is inclined downwards from the inner housing frame to the outer housing frame, i.e., it descends in the negative z-direction, and the inclination is approximately 9°.

[0045] In a further advantageous embodiment of the invention, the offset connection region is connected to the outer housing frame perpendicular to the plane of the mounting surface at the level of a connection height, wherein the connection height and / or the support section is arranged in the region of a vibration node of the outer housing frame in the event of a vibration of the outer housing frame excited by bonding.

[0046] The connection height is therefore in particular that position or that area in the z-direction at which or at which the offset connection area is connected to the outer housing frame. This embodiment is based in particular on the knowledge that in many examples it is primarily the outer housing frame that is excited to vibrate when bonds are created during manufacture of the power module. For example, the mounting surface can be electrically connected to electrical components arranged on the mounting surface, e.g. power semiconductors, by means of bonding or an ultrasonic connection technology, or the mounting surface can be electrically connected to the connection surfaces of the connection pins by means of bonding. During the aforementioned vibrations, the outer housing frame can vibrate in the area of ​​the short side explained, in particular in the direction of the inner housing frame.The vibrating outer housing frame has one or more vibration nodes, i.e., regions with zero vibration amplitude, and one or more antinodes, i.e., regions with maximum vibration amplitude. The vibration can be influenced by the connection of the outer housing frame to the base plate or the heat sink, so that the position of the vibration node(s) can change due to said connection.

[0047] The present embodiment now provides that the explained connection height is arranged in the region of a vibration node of the outer housing frame. This has the effect that even if the outer housing frame is excited to vibrate in the direction of the mounting surface during the production of bond connections, these vibrations are not transmitted, or are transmitted only insignificantly, by the outer housing frame via the offset connection region and the inner housing frame to the bond wires or the bonded electrical connections. Therefore, the present embodiment can make a significant contribution to facilitating a secure and permanent connection of bonded electrical connections within the power module.

[0048] Alternatively or additionally, the present embodiment provides that the above-described support section is arranged in the region of a vibration node of the outer housing frame. This also prevents or reduces the transmission of vibrations of the outer housing frame, which can be excited by the production of bond connections, via the offset connection region, possibly the support section and the base plate, and the inner housing frame to the bond wires or the bonded electrical connections.

[0049] The arrangement of the connection height or the support section in the region of a vibration node can be achieved in particular if the connection height or the support section is arranged up to 10%, in particular up to 5% or up to 3%, of the wavelength of the vibration occurring due to the bonding away from the vibration node. As a result, the amplitude of the vibration 21 in the region of the connection height or the support section is still comparatively small, so that a secure and permanent connection of bonded electrical connections within the power module can still be sufficiently ensured.

[0050] The wavelength of the vibration occurring during bonding or joining using an ultrasonic joining technique can be approximately 6 cm, for example in the case of an outer housing frame made of plastic and a frequency of 50 kHz.

[0051] Preferably, the inclination explained above is selected such that the offset connection region begins in the inner housing frame in the z-direction at the level of the respective bonding surface or the connection pin contact surface. In the outer housing frame or the support section, the offset connection region ends in the z-direction in particular at the level of the extension of the support section in the negative z-direction, i.e. for example at the level of the contact point of the support section on the base plate or on the heat sink. For example, the inclination of the offset connection region from the inner housing frame to the outer housing frame or to the support section is constant, so that the inclination from the inner housing frame to the outer housing frame is selected accordingly.

[0052] In a further advantageous embodiment of the invention, the outer housing frame and optionally the inner housing frame extend in the region of the short side, viewed perpendicular to the plane of the mounting surface, in at least one direction, preferably in both directions, beyond the respective offset connection region.

[0053] In particular, the above-mentioned upper edge of the outer housing frame in the region of the short side is located further up in the positive z-direction than the respective offset connection area. In addition, the above-mentioned lower edge of the outer housing frame in the region of the short side can be located further down in the negative z-direction than the respective offset connection area. The direction perpendicular to the plane of the mounting surface corresponds to the z-direction, which is oriented perpendicular to the xy-plane explained above.

[0054] In a further advantageous embodiment of the invention, the connecting region has a plurality of domes projecting from the connecting region in a direction perpendicular to the plane of the mounting surface, in particular for holding the mounting surface.

[0055] In some examples, the connection area, in particular the offset connection area, can have one or more domes that protrude from the remaining connection area in the positive or negative z-direction. For example, the domes can be provided to hold the mounting surface or as attachment points for the power module within the electrical device.

[0056] For the remaining design of the connecting area, and especially the offset connecting area, the domes can be disregarded in many examples. This applies particularly to the z-direction extension of the offset connecting area explained above.

[0057] In a further advantageous embodiment of the invention, the housing has at least two electrical connections.

[0058] For example, the power module can be provided for converting a (three-phase) alternating voltage into one or more direct voltages or vice versa. For this purpose, the housing has a corresponding number of electrical connections in the form of alternating voltage connections and direct voltage connections. Alternatively, the power module can be provided for converting a (three-phase) alternating voltage into another (three-phase) alternating voltage or for converting a direct voltage into another direct voltage, for which purpose the power module has corresponding electrical connections. Accordingly, the electrical device which has at least one such power module can be designed as a rectifier, inverter or converter.

[0059] In a further advantageous embodiment of the invention, the mounting surface is electrically connected by means of bonding or an ultrasonic connection technique to at least one connection pin comprised by the power module and / or to at least one electrical component comprised by the power module, in particular at least one power semiconductor.

[0060] For example, the mounting surface can be electrically connected to the respective connection pin and / or to the respective electrical component by means of one or more bonding wires, either by bonding or using an ultrasonic connection technique. For example, the respective electrical component can be designed as a power semiconductor, in particular as a transistor, e.g., as a power MOSFET (metal oxide semiconductor field-effect transistor) or as an IGBT (insulated-gate bipolar transistor), etc., or as a diode.

[0061] In a further advantageous embodiment of the invention, the power module can be operated with an electrical power of at least several 1 kW, preferably 40 kW to 500 kW, with an alternating voltage of at least several 10 V, preferably 280 V to 800 V, with a direct voltage of at least several 100 V, preferably 800 V to 1500 V, and / or electrical currents of several 1 A, preferably 70 A to 1000 A.

[0062] The invention is described and explained in more detail below with reference to the exemplary embodiments shown in the figures. They show:

[0063] FIGS 1-10 show a first to tenth embodiment of the proposed housing,

[0064] FIG 11 an embodiment of the proposed power module and

[0065] FIG 12 an embodiment of the proposed electrical device.

[0066] Figure 1 shows a first embodiment of the proposed housing 1, wherein a schematic, perspective view is shown.

[0067] The housing 1 has an outer housing frame 2, a connecting region 3 and an inner housing frame 4. In this case, the housing 1 is essentially rectangular in plan view. The housing 5 therefore has two opposing short sides 6 and two opposing long sides. Furthermore, the inner housing frame 4 is designed to receive and at least partially enclose a mounting surface 5. For example, the mounting surface 5 can for this purpose be designed essentially as a plate which can have an essentially rectangular shape, particularly in plan view. The outer housing frame 2 is arranged outside the inner housing frame 4 and is connected to the inner housing frame 4 via the connecting region 3. As shown in Figure 1, the outer housing frame 2, the connecting region 3 and the inner housing frame 4 can be sectioned, for examplein the area of ​​the long sides, merge into one another or be identical. In particular, in the area of ​​the respective short side 6, the outer housing frame 2, the connecting area 3 and the inner housing frame 4 are formed separately.

[0068] In the area of ​​the respective short side 6, the connecting area 3 has a stepped connecting area 7. In a plan view of the housing 1, the stepped connecting area 7 is arranged below the upper edge 8 of the outer housing frame 2 (again in the area of ​​the respective short side 6), which is indicated by an arrow in Figure 1.

[0069] For illustration purposes, the three axes of a Cartesian coordinate system are shown in Figure 1. Without loss of generality, the mounting surface 5 can span the xy plane. The outer housing frame 2 then extends in the region of the respective short side 6, in particular in the z direction, with the upper side of the mounting surface 5 pointing in the positive z direction and the underside of the mounting surface 5 pointing in the negative z direction. In a plan view of the housing 1, the offset connecting region 7 is thus arranged in the z direction below the upper edge 8 of the outer housing frame 2.

[0070] In some examples, the respective offset connection region 7 is inclined at least partially downwards or upwards from the inner housing frame 4 to the outer housing frame 2 when viewed from above onto the mounting surface 5. The inclination of the respective offset connection region 7 can in particular be between 3° and 30°, for example approximately 9°. An inclined, offset connection region 7 is illustrated and explained in more detail in Figures 6 to 10 and the associated figure description.

[0071] Figure 2 shows a second exemplary embodiment of the proposed housing 1, again depicting a schematic, perspective view. The same reference numerals as in Figure 1 designate the same elements.

[0072] In contrast to the first embodiment, according to the second embodiment of the proposed housing 1, the outer housing frame 2, the connecting region 3 and the inner housing frame 4 are always formed separately, i.e. also in the region of the long sides.

[0073] Figure 3 shows a third embodiment of the proposed housing 1, wherein a cross section through a section of the housing 1 is shown.

[0074] The third exemplary embodiment has some similarities to the first and second exemplary embodiments. As can be clearly seen in Figure 2, the offset connecting region 7 in the region of the short side 6 in the z-direction is arranged below the upper edge 8 of the outer housing frame 2 in a plan view. In addition, the offset connecting region 7 is also arranged above the lower edge 8' of the outer housing frame 2. This is indicated in Figure 3 by two corresponding arrows.

[0075] Furthermore, the offset connecting region 7 in the region of the short side 6 can also be arranged between an upper edge and a lower edge of the inner housing frame 4, as indicated in Figure 3. Furthermore, the inner housing frame 4 can have a projection which points towards the mounting surface 5 and on which the mounting surface 5 to be introduced can rest. Figure 4 shows a fourth exemplary embodiment of the proposed housing 1, again showing a cross-section through a section of the housing 1.

[0076] The fourth exemplary embodiment has some similarities to the three exemplary embodiments already explained. According to the fourth exemplary embodiment, the housing 1 has two connection pins 10. The connection pins 10 are arranged in the housing 1 in the region of the long side and aligned in the z-direction. At their lower end (i.e. at their end in the negative z-direction), the connection pins 10 each have a connection pin contact surface 11 by means of which the respective connection pin 10 can be electrically contacted. In particular, the respective connection pin 10 can be connected to the mounting surface 5 by means of a respective bonding wire 12 and by bonding or an ultrasonic connection technology.

[0077] The respective connection pin contact surfaces 11 are arranged at a height 14, wherein the height 14 refers to the plane of the mounting surface 5, i.e., it is a height in the z-direction. The offset connection region 7 is to be arranged in a height range 13 (again in the z-direction) around the said height 14.

[0078] For example, the height range 13 is ± 20 mm or ± 10 mm, so that the offset connection region 7 can be arranged or extend, for example, up to 20 mm or 10 mm higher or lower in the z-direction than the height 14 of the respective connection pin contact surface 11. In some examples, the height range 13 extends over three-quarters or, for example, one-quarter of the extension 15 of the outer housing frame 2 in a direction 22A, 22B perpendicular to the plane of the mounting surface 5, i.e. over three-quarters or, for example, one-quarter of the extension 15 of the outer housing frame 2 in the z-direction. Figure 5 shows a fifth exemplary embodiment of the proposed housing 1, again showing a cross-section through a section of the housing 1.

[0079] According to the fifth exemplary embodiment, the housing 1 is designed to accommodate a base plate or a heat sink 15, which, when viewed from above, can be arranged below the connecting region 3 and the inner housing frame 4. The housing 1 has a support section 16 at the respective offset connecting region 7, which support section can touch the base plate or the heat sink 15 or is connected thereto, whereby the base plate or the heat sink 15 can thus be fixed in the z-direction.

[0080] According to the fifth exemplary embodiment, the respective support section 16 is arranged at that end 17 of the offset connecting region 7 which faces the outer housing frame 2. With the Cartesian coordinate system used, the respective support section 16 is thus arranged at the end in the x-direction of the offset connecting region 7.

[0081] Figure 6 shows a sixth embodiment of the proposed housing 1, wherein again a cross section through a section of the housing 1 is shown.

[0082] According to the sixth exemplary embodiment, the offset connecting region 7 is inclined downwards from the inner housing frame 4 to the outer housing frame 2, i.e., along the positive x-direction in Figure 6, and downwards in the z-direction when viewed from above onto the mounting surface 5. A downward inclination 18 is present when the offset connecting region 7, aligned along the x-direction, is inclined downwards or counterclockwise in Figure 6 when viewed from the inner housing frame 4.

[0083] Preferably, the inclination 18 is between 3° and 30°, for example approximately 9°. Figure 7 shows a seventh embodiment of the proposed housing 1, again showing a cross-section through a section of the housing 1.

[0084] In contrast to the sixth exemplary embodiment, the offset connecting region 7 according to the seventh exemplary embodiment is inclined from the inner housing frame 4 to the outer housing frame 2, i.e., along the positive x-direction in Figure 7, and rising in the z-direction when viewed from above onto the mounting surface 5. This means, in particular, that the offset connecting region 7 aligned along the x-direction is inclined upwards or clockwise in Figure 7 when viewed from the inner housing frame 4.

[0085] Preferably, the inclination 18 is between 3 ° and 30 ° , for example approx . 9 ° .

[0086] Figure 8 shows an eighth embodiment of the proposed housing 1, wherein again a cross section through a section of the housing 1 is shown.

[0087] The eighth embodiment combines some aspects of the sixth and seventh embodiments. Thus, the housing 1 has the support section 16 at the respective offset connection area 7, which can contact the base plate or the heat sink 15 and thus fix the base plate 15 in the z-direction. Furthermore, the offset connection area 7 is inclined downwards from the inner housing frame 4 to the outer housing frame 2, i.e., in Figure 8, along the positive x-direction, and in a plan view of the mounting surface 5, downwards in the z-direction.

[0088] Figure 9 shows a ninth embodiment of the proposed housing 1, wherein again a cross section through a section of the housing 1 is shown.

[0089] According to the ninth exemplary embodiment, the offset connecting region 7 is connected to the outer housing frame 2 at a specific connecting height 19, wherein the connecting height 19 is a height perpendicular to the plane of the mounting surface 5 and thus a height in the z-direction. The connecting height 19 is arranged in the region of a vibration node 20 of the outer housing frame 2 during a vibration 21 of the outer housing frame 2 excited by bonding. The arrangement of the connecting height 19 in the region of a vibration node 20 can in particular be given if the connecting height 19 is arranged up to 10%, in particular up to 5% or up to 3%, of the wavelength of the vibration occurring due to bonding from the vibration node 2.

[0090] During production of the power module, for example, the bonding wires 11 shown and explained in Figure 4 can be electrically connected to the respective connection pin contact surface 11 or the mounting surface 5 by bonding or by means of an ultrasonic connection technique. During bonding or connecting, vibrations can be excited which also cause the outer housing frame 2 to vibrate 21, wherein the vibration 21 of the outer housing frame 2 can have one or more vibration nodes 20 with the vibration amplitude zero and one or more vibration antinodes with the maximum vibration amplitude. According to the ninth exemplary embodiment, the offset connection region 7 is connected to the outer housing frame 2 in the region of such a vibration node.

[0091] Preferably, the offset connecting region 7 is inclined from the inner housing frame 4 to the outer housing frame 2, i.e. in Figure 9 along the positive x-direction, and in a plan view of the mounting surface 5, downwards in the z-direction, as also shown in Figure 9. However, this is an optional feature, so that the offset connecting region 7 can also be inclined upwards or not be inclined at all. Figure 10 shows a tenth exemplary embodiment of the proposed housing 1, again showing a cross-section through a section of the housing 1.

[0092] The tenth exemplary embodiment of the proposed housing 1 has some similarities to the ninth exemplary embodiment. The offset connecting region 7 has the support section 16, which, according to the tenth exemplary embodiment, is arranged in the region of a vibration node 20 of the outer housing frame 2 during a vibration 21 of the outer housing frame 2 excited by bonding. The arrangement of the support section 16 in the region of a vibration node 20 can be given in particular if the support section 16 is arranged up to 10%, in particular up to 5% or up to 3%, of the wavelength of the vibration occurring due to bonding from the vibration node 20.

[0093] Furthermore, the offset connection area 7 can be connected to the outer housing frame 2 at the level of the connection height 19, as shown in Figure 10. The connection height

[0094] 19 can also be in the area of ​​a vibration node

[0095] 20 of the outer housing frame 2 in the case of a vibration 21 of the outer housing frame 2 excited by bonding, as already explained in connection with Figure 9.

[0096] Preferably, the offset connection region 7 is inclined from the inner housing frame 4 to the outer housing frame 2, i.e., in Figure 10, along the positive x-direction, and in a plan view of the mounting surface 5, downwards in the z-direction, as also shown in Figure 10. However, this is an optional feature, so that the offset connection region 7 can also be inclined upwards or not be inclined at all.

[0097] Figure 11 shows an embodiment of the proposed power module 30, wherein a plan view of the power module 30 is illustrated. The power module 30 has a housing 1 with an electrical connection 24, for example for an alternating voltage, and two further electrical connections 25, for example for two different direct voltages. Two electrical components 26, which can be designed as IGBTs, for example, are arranged on the mounting surface 5. The two electrical components 26 are connected to the mounting surface 5 via bonding wires 12. Furthermore, the mounting surface 5 is connected by means of bonding wires 12 to the connection pins 10, which are introduced into the housing 1.

[0098] Figure 12 shows an embodiment of the proposed electrical device 32, wherein a schematic view is shown.

[0099] The electrical device 32 can be designed, for example, as a converter, rectifier or inverter and has at least one power module 30.

Claims

Patent claims 1. Housing (1) for a power module (30), wherein the housing (1) is substantially rectangular in plan view and has an outer housing frame (2), a connecting region (3) and an inner housing frame (4), wherein the inner housing frame (4) is designed to receive and at least partially enclose a mounting surface (5) for at least one electrical component (26) of the power module (30), and wherein the outer housing frame (2) is arranged outside the inner housing frame (4) and is connected to the inner housing frame (4) via the connecting region (3), characterized in that the connecting region (3) has a stepped connecting region (7) in the region of the respective short side (6), which, when viewed from above, is arranged below the upper edge (8) of the outer housing frame (2) in the region of the respective short side (6).

2. Housing (1) according to claim 1, wherein the offset connecting region (7) is arranged in a plan view above the lower edge (8') of the outer housing frame (2) in the region of the respective short side (6).

3. Housing (1) according to one of the preceding claims, wherein the housing (1) has a plurality of connection pins (10), wherein the respective connection pin (10) has at its lower end a respective connection pin contact surface (11), via which the respective connection pin (10) can be connected to the mounting surface (5) by means of a bonding wire (12) or by means of an ultrasonic connection technique, and wherein the offset connection region (7), viewed perpendicular to the plane of the mounting surface (5), is arranged predominantly in a height range (13) around the height (14) of the respective connection pin contact surface (11).

4. Housing (1) according to claim 3, wherein the height range (13) is ± 20 mm, in particular ± 10 mm or ± 5 mm, and / or wherein the height range (13) extends over three quarters, in particular half or one quarter, of the extent (15) of the outer housing frame (2) in a direction (22A, 22B) perpendicular to the plane of the mounting surface (5).

5. Housing (1) according to one of the preceding claims, wherein the housing (1) in a plan view below the connecting region (3) and the inner housing frame (4) is designed to receive a base plate or a heat sink (15) and wherein the respective offset connecting region (7) has a support section (16) which touches the received base plate or the received heat sink (15) or is connected to it or this.

6. Housing (1) according to claim 5, wherein the respective support section (16) is arranged at that end (17) of the offset connecting region (7) which faces the outer housing frame (2).

7. Housing (1) according to one of the preceding claims, wherein the respective offset connecting region (7) from the inner housing frame (4) to the outer housing frame (2) is inclined at least in sections in a downward or upward direction when viewed from above onto the mounting surface (5).

8. Housing (1) according to claim 7, wherein the inclination (18) of the respective offset connecting region (7) is between 3° and 30°, preferably between 5° and 15°, in particular approximately 9°.

9. Housing (1) according to one of the preceding claims, in particular according to claim 5 or 6, wherein the offset connecting region (7) is connected to the outer housing frame (2) perpendicular to the plane of the mounting surface (5) at the level of a connecting height (19), and wherein the connecting height (19) and / or the support section (16) is arranged in the region of a vibration node (20) of the outer housing frame (2) during a vibration (21) of the outer housing frame (2) excited by bonding or an ultrasonic joining technique.

10. Housing (1) according to one of the preceding claims, wherein the outer housing frame (2) and optionally the inner housing frame (4) extend in the region of the short side (6) perpendicular to the plane of the mounting surface (5) in at least one direction (22A), preferably in both directions (22A, 22B), beyond the respective offset connection region (7).

11. Housing (1) according to one of the preceding claims, wherein the housing (1) has at least two voltage terminals (24, 25).

12. Power module (30) comprising - a housing (1) according to one of the preceding claims and - a mounting surface (5) for at least one electrical component (26), wherein the mounting surface (5) is received and at least partially enclosed by the inner housing frame (4).

13. Power module (30) according to claim 12, wherein the mounting surface (5) is electrically connected by means of an ultrasonic connection technique to at least one connection pin (10) comprised by the power module (30) and / or to at least one electrical component (26) comprised by the power module (30), in particular at least one power semiconductor.

14. Power module (30) according to claim 12 or 13, wherein the power module (30) is operable with an electrical power of at least several 1 kW, preferably 40 kW to 500 kW, with an AC voltage of at least several 10 V, preferably 280 V to 800 V, with a DC voltage of at least several 10 V, preferably 800 V to 1500 V, and / or electrical currents of several 1 A, preferably 70 A to 1000 A.

15. Electrical device (32), in particular a converter, comprising at least one housing (1) according to one of claims 1 to 11 and / or at least one power module (30), preferably at least three power modules (30), according to one of claims 11 to 14.

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