Power semiconductor module and cooler device

Abstract

The invention relates to a method for providing a cooler (12) for a power semiconductor module (10), wherein a cooling structure (32) is soldered to a flat surface of a substrate (14) or baseplate (15). The invention also relates to an arrangement of a power semiconductor module (10) formed according to the method.

Description

Technical Field

[0001] The present invention relates to an arrangement of a power semiconductor module and a cooler. In particular, the present invention relates to a power semiconductor module having an improved connection to a cooler and an improved arrangement of the cooler. The present invention also relates to methods of forming these. Background Art

[0002] Power semiconductor modules are well known in the art in various applications. For example, it is known to position a circuit soldered on a substrate in a housing and to encapsulate the circuit in a resin filled in the housing.

[0003] However, transfer molded and especially sintered power modules have become an interesting alternative to the conventional approach due to their enhanced cycle reliability. However, this increases the complexity of circuit integration, for example including three phases on a common substrate or cooler. Although the substrate can be fully assembled with wire bonds when subsequent substrate soldering is performed, the substrate for sintering cannot or can hardly be wire bonded and tested before sintering due to the strong pressure required on the substrate by the sintering approach. Pressure is usually applied mechanically using a rubber stamp, which will damage the wire bonds.

[0004] For this reason, for example, a one-step sintering of six-pack modules is economically very risky.It may be preferred to employ a six-pack configuration made of 3 different transfer-molded and sintered half-bridge modules.

[0005] However, there are different issues that need to be considered when using transfer molded modules.

[0006] For example, integration by using O-rings has room for improvement for reliability reasons (such as due to aging of the O-rings). The use of screws requires storage and part numbering for the assembly line. In addition, due to the number of screws (such as 4 screws for a half-bridge module), this solution requires space for the O-ring cavity and the screws.

[0007] It is important that the method or technology used for the integration of the circuit must not damage the power module. In particular, it may be preferred that the temperature does not exceed 225° C. in order not to damage the molding compound. Furthermore, mechanical stresses should be avoided.

[0008] It should also be avoided that the integration by welding technology creates small cracks and holes that cause leakage.

[0009] Besides this, the fluid encapsulation of the fluid-based cooler should be robust and leak-free and at the same time the design should be space-saving and inexpensive.

[0010] EP 3 276 657 A1 describes a power semiconductor module device with a cooler, wherein the cooler has a cooler body, a cavity formed in the cooler body, and a bonding wire. The bonding wire is arranged in the cavity and directly bonded to the first surface of the cooler body. The bonding wire contains at least 95% (weight percentage) aluminum; at least 0.25% (weight percentage) silicon; and at least 0.05% (weight percentage) magnesium and at least 0.05% (weight percentage) manganese.

[0011] US 2014 / 0327 127 A1 describes a power module comprising a semiconductor chip, a bonding substrate and an array of cooling structures, the bonding substrate comprising a conductive sheet and an electrically isolating sheet, the electrically isolating sheet being directly attached to the conductive sheet and thermally coupled to the semiconductor chip, the array of cooling structures being directly attached to the conductive sheet and being configured to remove heat from the semiconductor chip when interacting with a cooling fluid.

[0012] US 2013 / 0285 234 A1 describes a power module comprising a substrate having an electrically insulating member with opposite first and second metallized sides, and one or more semiconductor dies attached to the first metallized side of the substrate. A plurality of thermally conductive structures are laterally spaced apart from one another and individually attached directly to the second metallized side of the substrate such that the plurality of thermally conductive structures extend outwardly from the second metallized side.

[0013] US 2017 / 0304 922 A1 describes a semiconductor module comprising a substrate having a metallized first side and a metallized second side opposite the metallized first side. A semiconductor die is attached to the metallized first side of the substrate. A plurality of cooling structures are welded to the metallized second side of the substrate. Each of the cooling structures comprises a plurality of different weld beads, which are arranged in a stacked arrangement extending away from the substrate. The substrate may be conductive or electrically isolated. A corresponding method of manufacturing such a semiconductor module and substrate having such welded cooling structures is also provided.

[0014] CN207165550 U provides a module with liquid cooling.

[0015] CN203722992 U discloses an embedded multi-channel diffuse radiation module assembly.

[0016] US 9,578,789 B2 describes a power semiconductor module comprising a substrate and a two-piece cooling system arranged below the substrate. The cooling system has an upper part and a lower part. The upper part forms a flow channel for a cooling liquid together with the substrate. The upper part has a first inflow portion and an outflow portion, through which the cooling liquid can be introduced into the flow channel and removed. The upper part also has at least one second inflow portion, which is spaced apart from the first inflow portion in the longitudinal direction. The lower part has an inlet and an outlet, the outlet is connected to the outflow portion, and the inlet is connected to the first inflow portion. The lower part also has a channel branched from the inlet, the channel including at least one bypass channel, which is connected to the second inflow portion so that a portion of the cooling liquid travels through the bypass channel into the flow channel.

[0017] WO 2015 / 176914 A1 discloses a soldering process method for a radiator, wherein a heating component, an aluminum-based PCB board and a radiator are sequentially arranged from top to bottom, wherein the heating component and the aluminum-based PCB board are soldered as a whole via a soldering medium, and the whole is fixed to the radiator by means of soldering. The heat dissipation effect is enhanced by means of soldering, which changes the combination method of the heating component, the aluminum-based PCB board and the radiator.

[0018] US 2009 / 249624 A1 describes a method for manufacturing a heat sink, the method comprising the steps of providing a base and a plurality of individual fins, and welding the fins to the base in sequence by ultrasonic welding.

[0019] However, providing a cooler for a power semiconductor module, such as a transfer molded three-phase module, remains a problem. Thus, the prior art provides room for improvement in this regard. Summary of the invention

[0020] It is therefore an object of the present invention to provide a solution for at least partially overcoming at least one disadvantage of the prior art. An object of the present invention is in particular to provide a solution for connecting a power semiconductor module to an effective cooler in a simple and reliable manner.

[0021] These objects are at least partially solved by a method having the features of independent claim 1. These objects are further at least partially solved by an arrangement of a power semiconductor module and a cooler having the features of independent claim 13. Advantageous embodiments are given in the dependent claims, the further description and the drawings, wherein the described embodiments may provide features of the invention individually or in any combination of the respective embodiments, unless expressly excluded.

[0022] A method for providing a cooler for a power semiconductor module is described, the method comprising the following steps:

[0023] a): providing the power semiconductor module, the power semiconductor module comprising a substrate having a first substrate side for carrying at least one electronic circuit and having a second substrate side located opposite to the first substrate side, wherein

[0024] The power semiconductor module comprises one of features a1) and a2), wherein:

[0025] According to feature a1), the second substrate side has a planar surface and is adapted to be in contact with the cooler, wherein a cooling region is located at the second substrate side, the cooling region being surrounded by the connecting region, and wherein,

[0026] According to feature a2), the power semiconductor module comprises a substrate, wherein the substrate comprises a first substrate side and a second substrate side located opposite the first substrate side, wherein the second substrate side is connected to the first substrate side, wherein the second substrate side has a planar surface and is adapted to be in contact with the cooler, wherein a cooling region is located at the second substrate side, the cooling region being surrounded by the connection region;

[0027] Wherein, if the feature a1) is implemented, the method comprises the following steps:

[0028] b1): connecting a first housing part of the cooler to the second substrate side at the connection region, wherein the first housing part optionally comprises at least one opening for receiving the cooling region;

[0029] c1): connecting a second housing component to the first housing component such that a cooling channel is provided between the first housing component and the second housing component, the cooling channel being used to provide a cooling fluid to the cooling area; and

[0030] Step d1): welding a cooling structure to the cooling region at the second substrate side;

[0031] Alternatively, if feature a2) is implemented, the method comprises the following steps:

[0032] Step b2): connecting a first housing component of the cooler to the second substrate side at the connection region, wherein the first housing component selectively comprises at least one opening for receiving the cooling region;

[0033] Step c2): connecting a second housing component to the first housing component such that a cooling channel is provided between the first housing component and the second housing component, the cooling channel being used to provide cooling fluid to the cooling area; and

[0034] Step d2): Welding a cooling structure to the cooling area at the second substrate side.

[0035] This method may provide significant advantages over the cited prior art, particularly in terms of providing a cooler to the power semiconductor modules. In particular, the described method may be used to form an inverter.

[0036] In addition, it must be noted that the steps described above are not necessarily performed in the order described above. In particular, it may be preferred that step d1) is performed before step c1) or in parallel with step c1), and step d2) is performed before step c1) or in parallel with step c1).

[0037] According to a first method step a), a power semiconductor module is provided, which comprises a substrate and optionally a base plate. The substrate can in particular be a ceramic substrate carrying a power semiconductor device on a substrate metallization. The power semiconductor device can thus be fixed, for example, to the substrate metallization and can form a circuit together with other components such as terminals and corresponding interconnections.

[0038] Depending on the fact that the power semiconductor module has a base plate or not, the power semiconductor comprises one of the features a1) and a2), wherein the features a1) and a2) are explained in detail below.

[0039] According to feature a1), the second substrate side has a flat surface. This means in particular that the second substrate side (such as the bottom metallization) has a surface that is not provided with a specific cooling structure, but is formed, for example, by the ceramic body of the substrate and the corresponding metallization. Thus, the second substrate side and therefore the corresponding surface can extend parallel to the plane of the substrate or the body of the substrate, respectively.

[0040] The second substrate side is suitable for contact with a cooler. In this regard, it is provided that the second substrate side is equipped with a cooling area, which is surrounded by the connection area. The cooling area is therefore the active part with regard to cooling and is therefore the part that should be cooled by the cooler and should in particular be in contact with a cooling fluid guided through the cooler. However, the connection area is provided for connecting the substrate to the cooler, and therefore it is not necessary and undesirable for this area to be in contact with the cooling fluid, for example at least completely in contact.

[0041] According to feature a2) and therefore in case a base plate is present, the base plate is connected to the substrate in order to provide a particularly effective cooling effect of the power semiconductor device.

[0042] Thus, although the first substrate side is connected to the substrate and in detail to the second substrate side, the second substrate side is suitable for connection to a cooler. In this regard, it is provided that the second substrate side is equipped with a cooling area surrounded by the connection area. The cooling area is therefore an active part of the substrate and is therefore a part that should be cooled by the cooler and should in particular be in contact with a cooling fluid guided through the cooler. However, the connection area is provided for connecting the substrate to the cooler and therefore it is not necessary or desirable for this area to be in contact with the cooling fluid, for example at least completely in contact.

[0043] In addition, it is provided that the second substrate side has a flat surface. This means in particular that the second substrate side has a surface that is not provided with a specific cooling structure but is formed, for example, by the surface of the main body of the substrate itself. The second substrate side and therefore the corresponding surface can therefore extend parallel to the plane of the main body of the substrate and additionally, for example, parallel to the substrate.

[0044] For providing a power semiconductor module with a cooler, different options are possible, depending in particular on whether feature a1) is implemented or feature a2 is implemented. Generally, however, for the two named options (ie with or without baseplate), the method of providing a cooler is performed accordingly.

[0045] In more detail, if feature a1) is implemented, the method comprises the following steps.

[0046] According to method step b1), the first housing part of the cooler is connected and thus fixed to the second substrate side at the connection region. This is preferably performed by welding as described below. The first housing part can be formed, for example, from a flat plate or from a plate with a raised portion that allows easy handling. In addition, in order to reliably fix the second substrate side to the first housing part, for example by welding, it can be preferred that at least the connection region of the second substrate side can be realized at the substrate metallization.

[0047] The first housing part may comprise at least one opening for receiving the cooling region. In other words, in the case where the first housing part is attached to the substrate, the cooling region can still be exposed so that it can be cooled by the cooling fluid flowing through the cooler. The cooling region is thus received through the opening. However, the provision of the opening may depend in particular on the fact whether the cooling structure is arranged independently of the housing and in particular independently of the first housing part, or whether the cooling structure is connected to the first housing part as described in more detail below. In addition, since the first housing part is fixed to the connection region, the cooling region is surrounded by the first housing part and in particular by the edge of the opening.

[0048] Furthermore, according to method step c1), it is provided that the second housing part is connected to and thus fixed to the first housing part, wherein it is provided that a cooling channel is formed between the first housing part and the second housing part, which cooling channel is used to provide a cooling fluid to the cooling area. The cooling channel can be a free volume existing between the first housing part and the second cooling part, or the cooling channel can have a structure that guides the cooling fluid through a defined path.

[0049] According to method step d1), it is further provided that a cooling structure is welded to the cooling area at the second substrate side. The cooling structure is not particularly restricted and can include, in particular, turbulators, cooling pins and the like. For example, in the case where the cooling structure is formed by turbulators, the cooling structure can be formed in the form of waves with rounded edges or with angled edges. The crests and / or troughs can be flat, rounded or angled. The dimensions can be selected according to the required requirements. For example, the distance between the crests can be in the range between 2.5 mm and 5 mm, and the height from the trough to the crest can be in the range between 2 mm and 12 mm, wherein these values ​​are however not subject to any restrictions. In addition, it can be provided that the cooling structure is formed by aluminum.

[0050] According to this embodiment, the cooling efficiency of the cooler can be further improved compared to a flat cooling area. This may be mainly due to the fact that the surface of the substrate that can be cooled by the influence of the cooling fluid can be significantly increased.

[0051] As another example, a cooling structure may be formed by using cooling pins.

[0052] It may be provided that the first housing part has an opening adapted to receive the cooling structure. Furthermore, the distance between the first housing part and the second housing part should be selected such that there is sufficient space for placing the cooling structure. If the distance is greater than the length of the cooling structure, a fluid bypass may occur in the gap between the end of the cooling structure and the second housing part, which may lead to a reduction in thermal performance.

[0053] However, as an alternative to the above, if a substrate is present and therefore in the case of feature a2), the method comprises the following steps which correspond substantially to steps b1) to d1) described above.

[0054] According to method step b2), the first housing part of the cooler is connected and thus fixed to the second substrate side at the connection area. This is preferably done by welding as described below. The first housing part can be formed, for example, from a flat plate or from a plate including a raised portion that allows easy handling. In addition, in order to reliably fix the second substrate side to the first housing part, for example by welding, it can be preferred that at least the connection area of ​​the second substrate side can be formed from a metal or a metal alloy.

[0055] The first housing part may comprise at least one opening for receiving the cooling region. In other words, in the case where the first housing part is attached to the base plate, the cooling region can still be exposed so that it can be cooled by the cooling fluid flowing through the cooler. Again, the arrangement of the opening may depend in particular on the fact whether the cooling structure is arranged independently of the housing, and in particular independently of the first housing part, or whether the cooling structure is connected to the first housing part as described in more detail below.

[0056] Furthermore, according to method step c2), provision is made for connecting the second housing part to the first housing part and thus fixing it, wherein provision is made for providing a cooling channel between the first housing part and the second housing part, the cooling channel being used to provide a cooling fluid for the cooling area. The cooling channel can be a free volume present between the first housing part and the second housing part, or the cooling channel can have a structure for guiding the cooling fluid through a defined path.

[0057] According to method step d2), it is further provided that a cooling structure is welded to the cooling region at the second substrate side. The cooling structure is not particularly restricted and may in particular include turbulators, cooling pins and the like. According to this embodiment, the cooling efficiency of the cooler can be further improved. This may be mainly due to the fact that the surface of the substrate that can be cooled by the influence of the cooling fluid can be significantly increased.

[0058] The cooling structure may be formed, for example, by using cooling pins or by other structures as described above with respect to feature d1).

[0059] Furthermore, it can be provided that the first housing part has an opening suitable for receiving the cooling structure. In addition, the distance between the first housing part and the second housing part can be selected so that there is sufficient space for placing the cooling structure. If this distance is greater than the length of the cooling structure, a fluid bypass may occur in the gap between the end of the cooling structure and the second housing part, which may lead to a reduction in thermal performance.

[0060] The method as described above thus allows to provide a cooler at the power semiconductor module in a very efficient manner, which cooler, selectively by means of the base plate, exhibits a reliable and effective cooling behavior for the substrate and thus for the power semiconductor module. This is due to the fact that the power semiconductor module is cooled in a very efficient manner by providing a cooler with an effective cooling behavior based on the cooling fluid to be used.

[0061] Besides this, due to the soldering step a reliable connection of the cooling structure to the substrate or baseplate can be achieved, which ensures a long-term reliable arrangement.

[0062] With regard to the housing forming the cooler and thus the first housing part and the second housing part, it can be provided that the housing parts are formed from a copper alloy or an aluminum alloy. These alloys can have aluminum-coated areas which can come into contact with the cooling fluid. No other or further surface treatment is necessary, and a long-term stable arrangement is achieved even when the housing is in contact with the cooling fluid.

[0063] In general, it can be provided that the housing parts are formed from the same material, so that the welding conditions can be enhanced.

[0064] Generally, the first housing part may serve as a base plate and the second housing part may serve as a cap or cover, respectively, for closing the cooling channel.

[0065] For example, these advantages may be preferred for a sintered substrate or for a substrate with a power semiconductor device sintered thereon, respectively. In fact, substrates for sintering cannot be wire bonded and tested before sintering, because the sintering approach requires strong pressure on the substrate, which is usually applied mechanically with a rubber stamp, which may damage the wire bonds.

[0066] The soldering process does not affect the functionality of the power module and allows a reliable connection to be created without the use of O-rings and screws. This results in a compact solution with high reliability and high temperature ratings.

[0067] It can be provided that feature a1) is implemented and thus a base plate of the power semiconductor module can be omitted. Accordingly, it is provided that the method comprises step b1), step c1) and step d1).

[0068] This embodiment thus allows the formation of a power semiconductor module and thus an arrangement of a power semiconductor module with a cooler without a base plate. This embodiment thus allows a particularly simple and cost-effective production process of the power module and the corresponding arrangement. In addition to this, weight can be saved, which can be a particularly important advantage for mobile applications, for example in electric vehicles.

[0069] Alternatively, it can be provided that feature a2) is implemented and a baseplate of the power semiconductor module is provided and thus fixed to the substrate and thus to its second side, ie the second substrate side. Accordingly, it is provided that the method comprises steps b2), c2) and d2).

[0070] This embodiment allows to provide a particularly effective and reliable cooling effect, since the base plate can provide a cooling effect in addition to the cooler.

[0071] It can also be provided that the cooling structure is welded to the first housing part or the second housing part. According to this embodiment, a particularly reliable device can be provided, because the cooling structure is not only welded to and thus fixed to the substrate or base plate, but can also be fixed to the first housing part or the second housing part, which can result in improved mechanical stability.

[0072] Furthermore, it has been found that the cooling structure projecting into the cooling channel has a larger spatial dimension than the opening, so that a particularly effective cooling effect can be achieved.

[0073] Furthermore, the design and arrangement of the cooling structure can be realized in a very adaptable manner, since, independently of the size and geometry of the opening of the first housing part, different cooling structures can be used in each case depending on the respective requirements.

[0074] The cooling structure can thus be an initially separate component, in particular a separate component from the first housing part, and the first housing part can thus comprise an opening for receiving the cooling region and for receiving the cooling structure.

[0075] Alternatively, it can be provided that the cooling structure is designed in one piece with the first housing part or the second housing part and that the cooling structure is therefore part of the first housing part or the second housing part. This embodiment allows a particularly simple production process, since the step of connecting the cooling structure can be carried out in one step together with connecting the first housing part or the second housing part. Thus, process steps can be omitted, which can allow for significant advantages. In addition, it can be recognized again that the cooling structure protruding into the cooling channel has larger spatial dimensions than the opening, so that particularly effective cooling can be achieved.

[0076] Regarding the opening of the first shell part, it can be stipulated that if the cooling structure is designed to be integrated with the second shell part, the first shell part may include an opening for accommodating the cooling area and for accommodating the cooling structure; and in the case where the cooling structure is designed to be integrated with the first shell part, the corresponding opening in the first shell part is omitted.

[0077] In view of the above, at least one of the first housing part and the second housing part and the cooling structure may form a continuous structural element. This may be achieved by using a one-piece component or an integral component comprising at least one of the first housing part and the second housing part and the cooling structure, respectively. Alternatively, the continuous structural element may be formed by a connected (such as welded) two-piece component, wherein the cooling structure is connected (such as welded) to the first housing part or the second housing part.

[0078] It can further be preferred that the first housing part is connected to the second substrate side or to the second baseplate side by means of welding. This feature allows a particularly safe arrangement, since an arrangement with high mechanical stability can be achieved. In addition, welding can achieve that temperature influences on the module and therefore in particular on the power semiconductor components are kept below appropriate limits, so that the risk of damaging the power semiconductor components can be minimized or can be completely eliminated.

[0079] For the same reasons, it may be preferred to connect the second housing part to the first housing part by means of welding, even though the temperature influence on the power module may be lower compared to the fixing of the first housing part.

[0080] With regard to the welding step, it may be particularly preferred that at least one of the welding of the cooling structure, the welding of the first housing part or the welding of the second housing part is performed by means of laser welding. In particular, by means of laser welding, the temperature influence on the parts to be welded and thus on the power semiconductor module can be significantly reduced. This may be due to the fact that the temperatures generated when using laser welding can be kept in a range well below 250° C. Thus, damage to parts of the power semiconductor module, such as damage to the power semiconductor devices, can be prevented or at least reduced, so that the module as described above can be realized in a reliable manner.

[0081] It may further be preferred that, in the case of all the steps of step a1), step b1), step c1) and step d1), the first housing part is welded to the connection area of ​​the second substrate side along a welding path which completely surrounds the opening. According to this embodiment, due to the fact that a very stable connection path (such as a welding path) is achieved, a very reliable connection can be provided. In addition, in the case of the welding path surrounding the entire opening, the substrate is sealed against the first housing part, so that no further sealing is required. Therefore, the use of screws can be avoided and O-rings can be provided, which can improve reliability and also save space, because no grooves for O-rings and threaded holes for screws are required.

[0082] Accordingly, in the case of implementing all of step a2), step b2), step c2) and step d2), it may further be preferred that the first housing part is welded to the connection area on the second substrate side along a welding path that completely surrounds the opening. According to this embodiment, again, due to the fact that a very stable connection path (such as a welding path) is achieved, a very reliable connection can be provided. In addition, in the case where the welding path surrounds the entire opening, the substrate is sealed against the first housing part, so that no further sealing is required. Therefore, the use of screws can be avoided and O-rings can be provided, which can improve reliability and also save space, because no grooves for O-rings and threaded holes for screws are required.

[0083] It may further be preferred that step d1) is performed before step c1) and therefore in particular after step b1) or in parallel with step b1); or that step d2) is performed before step c2) and therefore in particular after step b2) or in parallel with step b1). This embodiment allows forming the cooling structure in a very adaptable manner, so that the cooling capacity can be adjusted according to the desired needs. In addition, steps for connecting the cooling structure, such as welding the cooling structure, can be performed particularly easily.

[0084] However, it can also be provided that step d1) is performed in parallel with step c1) and thus step d1) is performed simultaneously compared to step c1); or that step d2) is performed in parallel with step c2) and thus step d2) is performed simultaneously compared to step c2). This can be performed, for example, to increase the stability of the cooler or to improve the flow of the cooling medium. Furthermore, again, this embodiment allows the cooling structure to be formed in a very adaptive manner, so that the cooling capacity can be adjusted according to the desired needs. In addition to this, steps for connecting the cooling structure, such as welding the cooling structure, can be performed particularly easily.

[0085] It may further be preferred that at least one of the first housing part and the second housing part comprises at least one of a fluid inlet and a fluid outlet. Thus, this embodiment allows the arrangement of the first housing part and the second housing part to be used as a fluid-based cooler in a very effective and simple manner. In this regard, it may be appreciated that both the inlet and the outlet are arranged at the first housing part or at the second housing part; or that one of the inlet and the outlet is arranged at the first housing part and the other of the inlet and the outlet is arranged at the other part of the inlet and the outlet. However, for space reasons, it may be preferred that both the inlet and the outlet are arranged at the second housing part, which may also be regarded as a kind of cap.

[0086] As can be seen in detail above, in a specific embodiment, the proposed invention allows to integrate 3 single half-bridge modules with a flat substrate side or flat base plate into a common metal frame as a first housing part by welding technology and at the same time increase the heat transfer area or heat transfer area on the cooling medium side. In a second step, a cover as a second housing part is welded thereto to form, for example, a fluid basin. The welding process does not affect the functionality of the power module and allows to create a tightly sealed container without the use of O-rings and screws. This results in a compact solution with high reliability and high temperature ratings.

[0087] Furthermore, for example, temperature influences can be reduced, which in turn reduces the risk of negative effects on the power semiconductor components of the module.

[0088] In summary, the following advantages may occur when carrying out the described method.

[0089] First, the method can allow for reduced costs. In this regard, eliminating the pin-fin substrate or even the entire substrate and substrate-to-substrate joint from the bill of materials and manufacturing costs by replacing it with a much cheaper flat substrate or isolated metal substrate will enable a low-cost concept that is particularly attractive for mass-market automotive applications. The cooling structure (such as, a turbulator structure) can be provided as a separate component at a very low cost, or the cooling structure (such as, a turbulator structure) can be manufactured into the cooler frame (i.e., the first housing component) at little additional cost. In this concept, laser welding of the cooling structure can be achieved at little additional cost because the laser welding of the cooling structure can be performed in one step together with the laser welding of the cooler frame and each module only extends the process by a few seconds.

[0090] Furthermore, improved manufacturability may be obtained. This may be due to the fact that the flat module bottom side simplifies manufacturing by simpler testing (such as scanning acoustic microscopy) and simplified handling of parts, for example during the half-bridge assembly process.

[0091] Besides this, increased flexibility can be provided, since separation of the cooler structure from, for example, the half-bridge module allows changes to be implemented in the cooler structure, for example if the layout of the chip positions is changed, without expensive changes to the assembly line of the half-bridge modules, for example by adapting the fixture or the carrier geometry.

[0092] For other advantages and technical features of the method, reference may be made to the apparatus, drawings and other descriptions.

[0093] Furthermore, a power semiconductor module and a cooler arrangement is described, wherein the power semiconductor module comprises a substrate having a first substrate side carrying at least one circuit and having a second substrate side located opposite the first substrate side, wherein the power semiconductor module comprises one of the features a10) and a20), wherein

[0094] - According to feature a10), the second substrate side has a flat surface, and a cooling area is positioned at the second substrate side, the cooling area being surrounded by a connection area, wherein the second substrate side is in contact with the cooler so that a first housing part of the cooler is connected to the second substrate side at the connection area, wherein the first housing part selectively comprises at least one opening for receiving the cooling area, and wherein the second housing part is connected to the first housing part so that a cooling channel for a cooling fluid is provided between the first housing part and the second housing part, and wherein a cooling structure is welded to the cooling area at the second substrate side, wherein at least one of the first housing part and the second housing part forms a continuous structural element with the cooling structure; and wherein,

[0095] - According to feature a20), the power semiconductor module includes a substrate, wherein the substrate includes a first substrate side and a second substrate side positioned opposite to the first substrate side, wherein the first substrate side is connected to the second substrate side, and the second substrate side has a flat surface, and a cooling area is positioned at the second substrate side, the cooling area is surrounded by a connecting area, wherein the second substrate side is in contact with the cooler so that a first housing part of the cooler is connected to the second substrate side at the connecting area, wherein the first housing part selectively includes at least one opening for accommodating the cooling area, and wherein the second housing part is connected to the first housing part so that a cooling channel for cooling fluid is provided between the first housing part and the second housing part, and wherein a cooling structure is welded to the cooling area at the second substrate side, wherein at least one of the first housing part and the second housing part forms a continuous structural element with the cooling structure.

[0096] Such an arrangement may provide significant advantages over prior art solutions.Furthermore, the described arrangement may comprise or form an inverter, and / or the described arrangement may be formed according to the method described previously.

[0097] The feature according to which at least one of the first housing part and the second housing part forms a continuous structural element with the cooling structure can be realized by a one-piece component or an integral component comprising at least one of the first housing part and the second housing part and the cooling structure, respectively. Alternatively, the continuous structural element can be formed by a connected (such as welded) two-piece component, wherein the cooling structure is connected (such as welded) to the first housing part or the second housing part. Therefore, the continuous structural element can be understood as a common structural component.

[0098] The described device can provide improved manufacturability. In addition, the device can operate with efficient cooling and high reliability.

[0099] In this regard, the power semiconductor module comprises a plurality of power semiconductor devices. Such power semiconductor devices may generally be formed as known in the art and may in particular respectively comprise transistors or switches, such as MOSFETs and / or IGBTs, and / or the plurality of power semiconductor devices may comprise diodes in a non-limiting manner. The power semiconductor devices may be respectively interconnected and thus may be in electrical contact (such as galvanic contact) with corresponding regions of the lead frame, for example by soldering or sintering the power semiconductor devices to corresponding regions of the lead frame.

[0100] In order to allow mild operating conditions for the power semiconductor module and in particular for the power semiconductor devices, the power semiconductor module is connected and thermally coupled to a cooler directly via the substrate or by means of an additional base plate. The cooler thus serves to dissipate heat from the substrate and thus from the power semiconductor devices.

[0101] Thus, a long-term stable and reliable arrangement of the cooler may be provided, which allows for safe working behavior. This may be due to the fact that the fluid-based cooler has an efficient cooling capacity.

[0102] It may further be provided that the power semiconductor module is a transfer-molded module. According to this embodiment, significant advantageous effects may be achieved.

[0103] In this regard, transfer molded power semiconductor modules have become an interesting alternative to traditional gel or resin encapsulation approaches due to the following benefits, which are benefits regarding cost due to the fact that no housing is required, cycling reliability due to the fact that a hard mold and low CTE encapsulation of the power semiconductor devices and corresponding connections can be provided, environmental protection due to the low moisture absorption and vapor diffusion achieved, and further due to the vibration, shock and handling characteristics and warpage reduction. Therefore, transfer molded modules have significant advantages over prior art solutions.

[0104] It may further be provided that the power semiconductor module is a three-phase module. Again, this embodiment can particularly effectively demonstrate the advantages as described, especially with regard to three-phase modules, for which the connection of the substrate to the cooler is problematic according to the prior art.

[0105] Regarding the three-phase module, the following can be noted.

[0106] In a two-level traction inverter driving a three-phase machine, six functional semiconductor switches are required. For example, when looking at traction inverters for electric vehicles, the state-of-the-art technology usually involves integrating six-pack modules of three independent phases in a common base plate or cooler. A typical module of this design is based on a three-phase pin-fin base plate, a plastic frame glued to the base plate.

[0107] Preferably, the three-phase mold module is realized based on 3 separate mold modules and thus one half-bridge module per phase. Accordingly, the mold modules need to be attached to the cooler system after being molded.

[0108] However, according to the prior art, the one-step sintering approach of transfer molded six-pack modules is economically very risky. The first preferred solution is a six-pack configuration made of 3 different transfer molded and sintered half-bridge modules (i.e., three-phase modules). However, there are also significant challenges.

[0109] Integration by using O-rings has potential for improvement, mainly for reliability reasons, such as due to aging of the O-rings, and for the use of screws, which require storage and part numbering for the assembly line. In addition, this solution requires space for the screws, for example 4 screws per half-bridge module.

[0110] Furthermore, the method or technology used for integration must not damage the power module. In particular, the temperature should not exceed 225°C in order not to damage the molding compound, and mechanical stress should be avoided.

[0111] The fluid encapsulation should be robust and leak-free and at the same time the design should be space-saving and cheap and besides that eg the half-bridge module and its mechanical integration should be a low-cost process. For this reason it is preferred to eliminate the base plate or to use a flat base plate without cooling fin structures.

[0112] These problems are solved according to the invention in a very effective manner.

[0113] If a base plate is present, provision should be made that the base plate material is suitable for the chosen welding technology and should also have a surface finish that does not require coatings (such as nickel) for galvanic corrosion protection when installed in a cooling circuit. Examples of such materials could be: copper / aluminum base plates, where the aluminum is partly in contact with the cooling medium, or AlSiC base plates, for example aluminum-rich only in the welding area, or copper / aluminum composite base plates. In the case where the base plate is omitted, the same may apply to the corresponding materials of the substrate, where the metal or alloy can be formed as a bottom cladding metal on the main layer of the ceramic substrate.

[0114] The first housing part and the second housing part should be made of the same type of material (such as different aluminum alloys), while the welding techniques used can be different. For example, laser welding, which has low pressure, high speed and does not cause high welding temperature, can be used to weld the power module to the first housing part (also commonly referred to as the frame), as well as to weld the cooling structure. Relatively speaking, friction stir welding, laser welding, and cold metal transfer can be used to join the second housing part to the first housing part because the requirements in terms of maximum temperature and mechanical stress are less challenging. However, laser welding would be preferred for using one process for all welding steps.

[0115] Regarding the choice of material and technology for the substrate or base plate, a number of different options are possible, with the commonality being that the side opposite to the power semiconductor device and thus the chip (i.e. its second side) is flat and preferably made of aluminum, and that there is a layer electrically isolating the metallization layer on the upper side with the semiconductor chip from the cooling medium on the opposite side. The following examples are also possible in a non-limiting manner:

[0116] Ceramic substrates with copper or aluminum metallization combined or integrated with aluminum / AlSiC or copper / aluminum composite substrates;

[0117] Ceramic substrate with thick metallization layer (preferably aluminum metallization on the bottom side for laser welding) and no base plate;

[0118] • An isolated metal substrate with a thick metal layer (preferably aluminum) and an organic isolation layer on the bottom side, and no baseplate.

[0119] For other advantages and technical features of the device, please refer to the method, drawings and other descriptions. BRIEF DESCRIPTION OF THE DRAWINGS

[0120] These and other aspects of the invention will become apparent and elucidated with reference to the embodiments described below. The various features disclosed in the embodiments constitute aspects of the invention individually or in combination. Features of different embodiments may be transferred from one embodiment to another.

[0121] In the attached picture:

[0122] Figure 1 An embodiment of a power semiconductor module is shown;

[0123] Figure 2 An embodiment of a first housing component is shown;

[0124] Figure 3 shows the device fixed to the first housing part of the power semiconductor module after the welding step;

[0125] Figure 4 An arrangement is shown which is fixed to a first housing part of a power semiconductor module after fixing a cooling structure to a substrate of the power semiconductor module;

[0126] Figure 5 An arrangement of a power semiconductor module according to a first embodiment is shown with a first housing part and a second housing part, which are to be fastened to the power semiconductor module and to a cooling structure of a base plate;

[0127] Figure 6 An arrangement of a power semiconductor module according to a further embodiment is shown with a first housing part and a second housing part, which are to be fastened to the power semiconductor module and to a cooling structure of a base plate;

[0128] Figure 7 An embodiment of a second housing component is shown;

[0129] Figure 8 shows the arrangement of the second housing part being secured to the first housing part after the welding step;

[0130] Fig. 9 Another embodiment of a power semiconductor module is shown; and

[0131] Fig.10 A further exemplary embodiment of a power semiconductor module is shown. DETAILED DESCRIPTION

[0132] Figure 1 Shown is a power semiconductor module 10 which should be provided with a cooler 12 by using the method according to the invention, as shown in more detail below.

[0133] The power semiconductor module 10 comprises a substrate 14 having a first substrate side carrying at least one electronic circuit 18 and having a second substrate side 20 located opposite the first substrate side 16, as described below with respect to Figure 5 and Figure 6 as well as Fig. 9 and Fig.10 Shown in more detail.

[0134] In another embodiment, the second substrate side 20 may be connected to the base plate 15 , such that the following description regarding providing the cooler 12 at the substrate 14 may be transferred to provide the cooler 12 to the base plate 15 .

[0135] The electronic circuit 18 of the power semiconductor module 10 includes a power semiconductor device 22 which may be sintered to the substrate 14 and Figure 1 1 , this is not shown because the power semiconductor module 10 is a transfer-molded module. Therefore, a mold compound 24 is shown, which encapsulates the electronic circuit 18. Therefore, the power semiconductor module 10 is an overmolded module. However, the terminals 26 for externally contacting the electronic circuit 18 are shown as extending from the mold compound 24.

[0136] As described above, the substrate 14 includes a second substrate side 20, which is adapted to be in contact with the cooler 12. Thus, the cooler 12 will be connected to the second substrate side 20. Figure 1 , in particular the substrate metallization is shown, and the second substrate side 20 is formed.

[0137] The second substrate side 20 is provided with a cooling region 28 surrounded by a connection region 30. The cooling region 28 is adapted to be in contact with a cooling fluid or cooling structure 32 and the connection region 30 is adapted to be fixed to the cooler 12, as described in more detail below.

[0138] It is further shown that the second substrate side 20 and therefore also the cooling region 28 has a flat surface and is therefore free of any cooling structures 32 .

[0139] Such a power semiconductor module 10 may be, for example, a half-bridge module and may be part of a three-phase module, as this is often required, for example, for vehicles.

[0140] Also there Fig. 9 and Fig.10 Such a power semiconductor device is shown in FIG.

[0141] according to Fig. 9, shows a power semiconductor module 10, which is arranged substantially as described above. Thus, the power semiconductor module comprises a substrate 14, which carries a metallization 48 on a substrate isolation layer 50, wherein the substrate 14 or the second side 20 of the substrate is flat so as to be in contact with the cooler 12 and so as to solder the cooling structure 32 to the substrate or the second side of the substrate. The power semiconductor devices 22 of the electronic circuit 18 are connected to other areas of the metallization 48, for example by means of wirebond connections 54. It can also be seen that the electronic circuit 18 is encapsulated by the molding compound 24.

[0142] according to Fig.10 The device comprises an additional substrate 15 having a first substrate side 17 connected to a second substrate side 20 and also having a second substrate side 19. The second substrate side 19 is flat in order to be in contact with the cooler 12 and in order to solder the cooling structure 32 thereto.

[0143] In order to provide the power semiconductor module 10 with a cooler 12, provision is made for a first housing part 34 of the cooler 12 to be connected to the second substrate side 20 at the connection region 30. The first housing part 34 can be formed from aluminum. In order for the cooling structure 32 and the cooling region 28, which should be fixed to the second substrate side 20 at a subsequent stage, to function under the operating conditions of the cooler 12, in this embodiment, the first housing part 34 comprises an opening 36 for receiving the cooling region 28 and thus the subsequently attached cooling structure 32.

[0144] exist Figure 2 Such a first housing part 34 is shown in FIG. The first housing part 34 is shown to include three openings 36, which may be suitable for receiving three power semiconductor modules 10, such as three half-bridge modules. Also shown are holes 38, which are used to fix the arrangement of the cooler 12 and the power semiconductor modules 10 to, for example, a support.

[0145] Figure 3 A top view of a first housing part 34 is shown, which is fixed to the power semiconductor module 10 or to its substrate 14 respectively by means of a welding step. This step can be performed, for example, by means of laser welding.

[0146] In more detail, it is shown that the first housing component 34 is secured to the substrate 14 by a continuous weld path 40 that runs continuously around the entire opening 36. Thus, the weld path 40 provides mechanical stability as well as sealing the first housing component 34 against the substrate 14.

[0147] Figure 4 Another view of the first housing part 34 fixed to the power semiconductor module 10 is shown. Figure 4 It can be seen that a cooling structure 32 is welded to each cooling region 28 of the second substrate side 20 of the substrate 14 to increase the heat transfer area or surface. The cooling structure 32 is formed in a wavy shape, wherein this arrangement is not intended to limit the present invention.

[0148] exist Figure 4 In the embodiment of the present invention, the type of turbulators as cooling structures 32 is the same for all three half-bridge modules, but their geometry or type can also be different. For example, the crests of the turbulators in the flow direction can be increased in order to reduce the heat accumulation effect and achieve an improved cooling area or achieve more turbulence. One of the advantages of welding the cooling structures 32 is that, for example, different types of cooling structures 32 can be combined, thereby providing high flexibility in terms of thermal design.

[0149] exist Figure 5 and Figure 6 The arrangement of the cooling structure 32 is further shown in FIG.

[0150] In detail, Figure 5 1 shows a power semiconductor module 10 comprising a substrate 14 having a first substrate side 16 carrying at least one electronic circuit 18 and having a second substrate side 20 located opposite the first substrate side 16. The first substrate side 16 comprises a metallization 48 connected to a base metal layer 51 of the substrate 14, for example, via a spacer sheet 52. The power semiconductor devices 22 of the electronic circuit 18 are connected to other areas of the metallization 48 by means of wire bonding connections 54. It can also be seen that the circuit is encapsulated by a molding compound 24.

[0151] With respect to the second substrate side 20, the connection of the first housing part 34 to the substrate 12 is shown. In more detail, it can be seen that the first housing part 34 comprises a cooling structure 32, which is formed in one piece with the first housing part 34. Furthermore, the second housing part 42 should be connected to the first housing part 34. The arrows should indicate that the second housing part 42 and the first housing part 34 including the cooling structure 32 are respectively fixed by means of welding, so that the first housing part 34 is welded to the connection area 30, the cooling structure 32 is welded to the cooling area 28, and the second housing part 42 is welded to the first housing part 34 and optionally also to the cooling structure 32.

[0152] The integral arrangement of the cooling structure 32 and the first housing part 34 can be achieved by: manufacturing the cooling structure 32 directly into the first housing part 34 formed as a cooler frame part, for example, by any combination of stamping, machining, deformation process, deep drawing, etc.; or by preassembling the first housing part 34 and the cooling structure 32 as separate components and connecting the first housing part and the cooling structure together by any bonding process such as welding, brazing, gluing, etc. before assembling the first housing part and the cooling structure to the power semiconductor module 10.

[0153] Figure 6 Shown with Figure 5 The embodiments of the present invention are similar to those of the embodiments of the present invention, so reference is made generally to the corresponding description. Figure 6 Examples and Figure 5 The embodiment of ATHENA ® differs in the fact that the cooling structure 32 is welded to the cooling region 28 , but the element forming the cooling structure is also welded to the first housing part 34 and is therefore initially a different part than the first housing part 34 .

[0154] Furthermore and with regard to the cooler 12 , in order to form the cooler, it is further provided that the second housing part 42 is connected to the first housing part 34 and optionally also to the cooling structure 32 .

[0155] exist Figure 7 4 , which shows that the second housing component 42 includes two openings 44 that can be used as an inlet and an outlet for guiding the cooling fluid through the cooler 12 .

[0156] In more detail and as Figure 8 As shown, it is provided that the second housing part 42 is fixed to the first housing part 34, so that a cooling channel is provided between the first housing part 34 and the second housing part 42, which cooling channel is used to provide a cooling fluid for the cooling area 28 or the cooling structure 32. This is achieved by welding the second housing part 42 to the first housing part 34 by means of a welding technique along a welding path 46, which completely surrounds the cooling channel. It can be provided that this welding step is performed by means of friction stir welding, laser welding and cold metal transfer, because the requirements in terms of maximum temperature and mechanical stress are less challenging than the welding step of fixing the first housing part 34 and the cooling structure 32 to the substrate 14.

[0157] Returning to the subsequent welding step of fixing the first housing component 34 to the substrate 14, the material for the substrate or substrate metallization can be selected as an optimal compromise between thermal performance, reliability, corrosion resistance and weldability. The latter point may be of high relevance. In order to avoid brittle intermetallic phases, the material of the substrate 14 at the welding interface and therefore at the connection area 30 can also be formed of aluminum.

[0158] Returning to the previous figures, it can be seen that the first housing part 34 includes a protuberance 35, which can form a cooling channel when the first housing part 34 is fixed to the second housing part 42 as shown above. In this case, the first housing part 34 can form a cooling basin enclosed by the second housing part 42.

[0159] Therefore, according to a preferred embodiment without limiting the invention, a solution to the above mentioned problem is provided by combining the integration of the power module 10 into a common frame as the first housing part 34 by using welding technology combined with increasing the substrate or baseplate heat transfer area in contact with the cooling medium. The increase of the heat transfer area of ​​the power module 10 with a flat plate is crucial to cope with the high heat flux density generated by the die during switching operation.

[0160] To cool them effectively, a larger heat transfer area is required compared to a flat plate as well as high turbulence to increase the fluid heat transfer coefficient. This can be achieved in an efficient and cost competitive manner by welding aluminum turbulators or similar cooling structures 32 to the substrate or base plate side in contact with the cooling medium. Aluminum turbulators are inexpensive and are the most advanced fins used in the automotive industry for air conditioning and oil heat exchangers. They can be of different shapes and sizes. The selection is based on the cooling requirements, such as cooling medium and turbulence, minimum allowed clearances, etc.

[0161] The turbulators or similar cooling structures may be inserted as separate parts and welded to the substrate or base plate, or alternatively the cooling structure may be an integral part of the cooler frame.

[0162] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description should be considered illustrative or exemplary rather than restrictive; the present invention is not limited to the disclosed embodiments. Other variations of the embodiments to be disclosed can be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure and the appended claims. In the claims, the words "comprise" or "comprising" do not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude the plurality. The fact that certain measures are recorded in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any figure signs in the claims should not be considered as limiting the scope.

[0163] Reference numerals list

[0164] 10 Power semiconductor modules

[0165] 12 Cooler

[0166] 14 Substrate

[0167] 15 substrate

[0168] 16 First substrate side

[0169] 17 First substrate side

[0170] 18 Circuit

[0171] 19 Second substrate side

[0172] 20 Second substrate side

[0173] 22 Power semiconductor devices

[0174] 24 Molding Compound

[0175] 26 terminals

[0176] 28 Cooling Zone

[0177] 30 Connection Area

[0178] 32 Cooling structure

[0179] 34 first housing component

[0180] 35 ridge

[0181] 36 Opening

[0182] 38 holes

[0183] 40 welding paths

[0184] 42 second housing member

[0185] 44 Opening

[0186] 46 welding paths

[0187] 48 Metallization

[0188] 50 Isolation Layer

[0189] 51 base metal layer

[0190] 52 Isolation Sheet

[0191] 54 Wire Bonding Connectors

Claims

1. A method for providing a cooler (12) for a power semiconductor module (10), the method comprising the following steps: a) providing the power semiconductor module (10), the power semiconductor module (10) comprising a substrate (14), the substrate (14) having a first substrate side (16) for carrying at least one electronic circuit (18) and having a second substrate side (20) located opposite the first substrate side (16), wherein: The power semiconductor module (10) comprises one of the features a1) and a2), wherein: According to feature a1), the second substrate side (20) has a flat surface and is suitable for contacting the cooler (12), wherein a cooling area (28) is located at the second substrate side (20), the cooling area (28) being surrounded by a connection area (30), and wherein, According to feature a2), the power semiconductor module (10) comprises a substrate (15), wherein the substrate (15) comprises a first substrate side (17) and a second substrate side (19) located opposite the first substrate side (17), wherein the second substrate side (20) is connected to the first substrate side (17), wherein the second substrate side (19) has a flat surface and is suitable for contacting the cooler (12), wherein a cooling area (28) is located at the second substrate side (19), and the cooling area (28) is surrounded by a connection area (30); Wherein, if the feature a1) is implemented, the method comprises the following steps: b1) connecting a first housing part (34) of the cooler (12) to the second substrate side (20) at the connection region (30), wherein the first housing part (34) optionally comprises at least one opening (36) for receiving the cooling region (28); c1) connecting a second housing component (42) to the first housing component (34) such that a cooling channel is provided between the first housing component (34) and the second housing component (42), the cooling channel being used to provide a cooling fluid to the cooling region (28); and d1) welding a cooling structure (32) to the cooling region (28) at the second substrate side (20); Alternatively, if feature a2) is implemented, the method comprises the following steps: b2) connecting a first housing part (34) of the cooler (12) to the second substrate side (19) at the connection region (30), wherein the first housing part (34) optionally comprises at least one opening (36) for receiving the cooling region (28); c2) connecting a second housing component (42) to the first housing component (34) such that a cooling channel is provided between the first housing component (34) and the second housing component (42), the cooling channel being used to provide a cooling fluid to the cooling region (28); and d2) welding a cooling structure (32) to the cooling region (28) at the second substrate side (19), The cooling structure (32) is directly manufactured into the first shell component (34) to achieve an integrated form of the cooling structure (32) and the first shell component (34).

2. The method according to claim 1, characterized in that The feature a1) is achieved.

3. The method according to claim 1, characterized in that The feature a2) is achieved.

4. The method according to any one of claims 1 to 3, characterized in that The cooling structure (32) is welded to the first housing component (34) or to the second housing component (42).

5. The method according to any one of claims 1 to 3, characterized in that The cooling structure (32) and the second housing component (42) are designed in an integrated form.

6. The method according to any one of claims 1 to 3, characterized in that The first housing part (34) is connected to the second substrate side (20) or to the second baseplate side (19) by means of welding.

7. The method according to any one of claims 1 to 3, characterized in that The second housing part (42) is connected to the first housing part (34) by means of welding.

8. The method according to claim 1 or 2, characterized in that: In the case of all steps a1), b1), c1) and d1), the first housing part (34) is welded to the connection region (30) of the second substrate side (20) along a welding path (40) which completely surrounds the opening (36).

9. The method according to claim 1 or 3, characterized in that: In the case of all steps a2), b2), c2) and d2), the first housing part (34) is welded to the connection area (30) of the second substrate side (19) along a welding path (40) which completely surrounds the opening (36).

10. The method according to any one of claims 1 to 3, characterized in that At least one of the welding of the cooling structure (32), the welding of the first housing component (34) or the welding of the second housing component (42) is performed by means of laser welding.

11. The method according to any one of claims 1 to 3, characterized in that Step d1) is performed before step c1), or step d2) is performed before step c2).

12. The method according to any one of claims 1 to 3, characterized in that The step d1) is performed in parallel with the step c1), or the step d2) is performed in parallel with the step c2).

13. A device of a power semiconductor module (10) and a cooler (12), wherein: The power semiconductor module (10) comprises a substrate (14) having a first substrate side (16) carrying at least one electronic circuit (18) and having a second substrate side (20) located opposite the first substrate side (16), wherein the power semiconductor module (10) comprises one of features a10) and a20), wherein: - According to feature a10), the second substrate side (20) has a flat surface, and a cooling area (28) is located at the second substrate side (20), the cooling area (28) being surrounded by a connection area (30), wherein the second substrate side (20) is in contact with the cooler (12), so that at the connection area (30) a first housing part (34) of the cooler (12) is connected to the second substrate side (20), wherein the first housing part (34) optionally comprises at least one opening (36) for receiving the cooling area (28), and wherein a second housing part (42) is connected to the first housing part (34), so that a cooling channel for a cooling fluid is provided between the first housing part (34) and the second housing part (42), and wherein a cooling structure (32) is welded to the cooling area (28) at the second substrate side (20) of the substrate (14), wherein at least one of the first housing part (34) and the second housing part (42) forms a continuous structural element with the cooling structure (32); and wherein, - According to feature a20), the power semiconductor module (10) comprises a substrate (15), wherein the substrate (15) comprises a first substrate side (17) and a second substrate side (19) located opposite the first substrate side (17), wherein the first substrate side (17) is connected to the second substrate side (20), and the second substrate side (19) has a flat surface, and a cooling area (28) is located at the second substrate side (19), the cooling area (28) is surrounded by a connection area (30), wherein the second substrate side (19) is in contact with the cooler (12), so that at the connection area (30) a first housing part (34) of the cooler (12) is ) is connected to the second substrate side (19) of the substrate (15), wherein the first housing part (34) selectively comprises at least one opening (36) for receiving the cooling area (28), and wherein a second housing part (42) is connected to the first housing part (34) such that a cooling channel for a cooling fluid is provided between the first housing part (34) and the second housing part (42), and wherein a cooling structure (32) is welded to the cooling area (28) at the second substrate side (19), wherein at least one of the first housing part (34) and the second housing part (42) forms a continuous structural element with the cooling structure (32), The cooling structure (32) is directly manufactured into the first shell component (34) to achieve an integrated form of the cooling structure (32) and the first shell component (34).

14. The device according to claim 13, characterized in that The power semiconductor module (10) is a transfer-molded module.

15. The device according to claim 13 or claim 14, characterized in that The power semiconductor module (10) is a three-phase module.

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