Method for producing SMD power semiconductor component module and SMD power semiconductor component module

Abstract

The invention relates to a method for producing an SMD power semiconductor component module, comprising the following steps: providing an SMD circuit carrier (1, 10) provided with a contact point (3) and an insulation; providing at least one discrete power semiconductor component (4) provided with an electrically conductive connection element (5), preferably a connection leg; arranging the at least one discrete power semiconductor component (4) provided with an electrically conductive connecting element (5) on the side of the SMD circuit carrier (1, 10) provided with the contact point (3), the connecting element (5) of the power semiconductor component (4) contacting the contact point (3) of the SMD circuit carrier (1, 10); and connecting the connecting elements (5) to the respectively arranged contact points (3) by means of laser welding.

Description

Technical Field

[0001] The invention relates to a method for producing an SMD power semiconductor component module, in which at least one discrete power semiconductor component provided with electrically conductive connecting elements is mounted in an SMD construction on an SMD circuit carrier provided with contact locations. In this case, mechanical fastening and electrical contacting take place on the same side of the SMD circuit carrier. The invention also relates to an SMD power semiconductor component module, which is produced according to the method according to the invention. Background Art

[0002] Discrete SMD power semiconductor components are now used as SMD components in large quantities and are soldered on SMD circuit carriers, such as printed circuit boards (PCBs) or IMS substrates, by a soldering method. All three contacts of this component, namely the collector, emitter and gate, are soldered to the current conductors of the SMD circuit carrier. As the effective power of the power semiconductor chip rises, the current intensity also rises, so that the newer power semiconductor chips have a higher current carrying capacity. Due to the higher current in these components, the contacts are heated more strongly, thereby reducing the reliability in the application. Therefore, the type of connection of the contacts in the power semiconductor component determines the current carrying capacity of the power semiconductor component. This means that in an emergency, the current must be reduced or limited in order to ensure the required reliability of the circuit. It has become particularly important that the power circuit including the SMD component is constructed on a circuit carrier, which can also bear the enhanced cooling function of the circuit differently from the PCB. Then, the small copper cross-section of the connecting leg and the additional ohmic impedance based on the soldering connection cause losses, which hinder the economic utilization of the current carrying capacity of the chip or reduce the reliability of the circuit.

[0003] Printing technology

[0004] A method according to the preamble of claim 1 is known from DE 10 2013 213 448 B4. In this case, the power semiconductor is mounted on the top side of a substrate, the bottom side of which is connected to a heat sink. The electrical connection of the power semiconductor and the contact points of the substrate is carried out by soldering in a reflow process.

[0005] EP 2 458 632 A1 discloses a heat sink module for electronic semiconductor devices, in which a plurality of electronic semiconductor devices are fixed to a ribbed output body by means of a fastening frame, leaf springs and fastening screws. The fastening frame specifies the exact arrangement of the individual semiconductor devices. The connecting legs of the electronic semiconductor devices extend through the circuit board in a vertical direction and are connected to the circuit board on the side of the circuit board opposite to the heat sink module by sonic welding or point-to-point welding. The mechanical fastening plane and the electrical connection plane of the electronic semiconductor device are therefore located on different sides of the circuit board.

[0006] DE 10 2019 205 772 A1 discloses a power module comprising encapsulated power semiconductors for controllably supplying electrical power to a consumer. For cooling, a cooling body comprising a cooling surface is provided on the underside of a circuit board. The power semiconductor is directly fastened to the cooling body and protrudes through a through hole that is compulsorily provided in the circuit board. The connecting elements of the power semiconductor are electrically connected to the connecting surface on the side of the circuit board facing away from the cooling body. Soldering, in particular gap head soldering, but also welding are mentioned as possible connections. However, SMD power semiconductor components are not involved here, because the fastening of the power semiconductor is carried out directly on the cooling body. The power semiconductor must be provided with an insulating portion on the underside, because the power semiconductor is directly fastened to the upper side of the cooling body. Summary of the invention

[0007] Mission of the present invention

[0008] The object of the present invention is to provide a method which allows the production of SMD power semiconductor component modules having a high current carrying capacity using simple production technology.

[0009] Solving the task

[0010] This object is achieved by the features of claim 1. Advantageous embodiments of the method according to the invention are claimed in the dependent claims. Claim 25 teaches an SMD power semiconductor component module according to the invention.

[0011] The method for manufacturing an SMD power semiconductor assembly module according to the present invention comprises the following steps:

[0012] providing an SMD circuit carrier provided with contact points and an insulation or an insulator, providing at least one discrete power semiconductor component provided with an electrically conductive connecting element,

[0013] Arranging the at least one discrete power semiconductor component provided with an electrically conductive connecting element on the side of the SMD circuit carrier provided with the contact locations, wherein the connecting elements of the power semiconductor component make contact with the contact locations of the SMD circuit carrier, and

[0014] The connecting elements are connected to the respectively assigned contact locations by laser welding.

[0015] Preferably, within the scope of the method according to the invention, power semiconductor components are used which have electrical contact connections on the bottom side (ie without insulation).

[0016] Preferably, the SMD circuit carrier comprises a cooling function.

[0017] Preferably, a printed circuit board, a so-called IMS substrate or a lead frame is provided as an SMD circuit carrier. The IMS substrate is a conductor track structure on an insulator. The lead frame is a metal grid, for example a punched grid, which forms the conductor track. The conductor track can be insulated and / or provided with a cooling structure or a cooling body or a cooling layer.

[0018] Therefore, in the process of the method according to the present invention, the power semiconductor assembly is fastened on the same side of the SMD circuit carrier in an SMD construction mode, and the electrical contact of the connecting element of the power semiconductor assembly on the SMD circuit carrier is made on the side. Therefore, the mechanical fastening plane and the electrical contact plane are the same or at least parallel to each other on the same side of the SMD circuit carrier. The assembly of the SMD power semiconductor assembly module is thus completely and significantly simplified. Based on the connection of the connecting element with the respectively configured contact position by laser welding instead of soldering, the current carrying capacity of the SMD power semiconductor assembly module is also significantly improved. In laser welding, the connecting element and the contact position in the relevant area of ​​the laser beam melt, thereby producing a tight connection of the joining partner. Therefore, the connection of a single metal can be manufactured by laser welding. The following advantage is thus generated, that is, the material-locked connection of this type allows the SMD power semiconductor assembly module to operate with a higher current intensity, unlike the soldering connection. In addition, the connection according to the present invention also allows the SMD power semiconductor assembly module to operate at a higher temperature than the temperature possible during the soldering connection. In addition, compared to the soldering connection, a more durable operation under high load change conditions is possible. This makes it possible to achieve a high reliability of the SMD power semiconductor component module. Furthermore, it is achieved that the power semiconductor component module can be operated at the full effective power of its power semiconductor components, ie no “limiting” has to take place.

[0019] The contacting of the (contact location and connecting element) is the contacting that is common for soldering connections, in which the contact location and / or the connecting element are made of copper or a copper alloy. As a result, the method according to the invention can be used in conventional semiconductor components (e.g. TO 263; D 2 Pack, SO-8) or circuit carriers (e.g. circuit boards, PCBs, DCB substrates, IMS substrates, lead frames), wherein corresponding contact connections are always provided. This is particularly advantageous when the power circuit including SMD components is constructed on an IMS substrate, which, unlike a PCB, can also assume an enhanced cooling function for the circuit. Then the small copper cross section of the connection end and the additional ohmic impedance will lead to losses in conventional soft soldering, which hinder the economic use of the current carrying capacity of the chip or reduce the reliability of the circuit. This can be effectively avoided by the present invention. The contact locations and / or the connecting elements can be pre-tinned here.

[0020] Advantageously, the connecting element is designed to extend parallel to a main extension area of ​​the SMD circuit carrier in the region of the connecting element in which the laser welding takes place.

[0021] Preferably, the connecting element is a so-called connecting leg, in which a particularly small connecting end cross section is provided. The method according to the invention is particularly advantageous here, since laser welding results in a lower ohmic resistance than a soldered connection.

[0022] Preferably, in the case of a power semiconductor component, the laser welding can be limited only to the region of the connecting legs. Preferably, no laser welds are provided in the region of the further underside contact region of the power semiconductor component comprising the SMD circuit carrier.

[0023] The connecting legs are preferably designed in a stepped manner, whereby on the one hand they extend parallel to the connecting plane in the area to be welded and / or are adapted to the structural height of the arrangement. On the other hand, this offers the advantage that the laser beam can be coupled from above undisturbed and uniformly to the location to be welded.

[0024] Studies have shown that it is particularly advantageous to form the laser welded connection via a connected melt zone, thereby enabling uniform energy input at a small contact surface due to the narrow connecting legs, thereby providing an effective and stable contact.

[0025] It is particularly advantageous to carry out the laser welding connection alternatively or additionally by means of an oscillating laser beam. This also enlarges the area of ​​the laser beam coupling and thereby avoids local excessive melting that could lead to perforations.

[0026] The laser welding is preferably carried out using an IR laser. The use of an IR laser has proven to be very advantageous because, through its use, oxides, in particular copper oxide, are first formed on the surface of the welding location, whereby the reflectivity for the laser beam is reduced and thus improved coupling of the laser beam or its energy can be achieved.

[0027] According to a further embodiment, the at least one power semiconductor component, preferably a plurality of power semiconductor components, which are discrete and provided with electrically conductive connecting elements, can be situated between the SMD circuit carrier and the holding component.

[0028] The at least one discrete power semiconductor component, preferably the plurality of power semiconductor components, which are provided with conductive connecting elements, can be first positioned and fixed on the holding component before the laser welding based on a special embodiment of the method according to the present invention. The holding component acts as a transfer component in this case. In this case, the discrete one power semiconductor component or the discrete plurality of power semiconductor components can already be fixed on the holding component in a special arrangement structure, for example a circular or star-shaped arrangement structure. This can involve an arrangement structure that is ultimately to be specified in advance in a certain application. The holding component can be retained on the power semiconductor component module to be manufactured in a suitable embodiment, so that the power semiconductor component is reliably stabilized in its position during its subsequent laser welding. The holding component also serves as a mechanical support in the overall arrangement structure.

[0029] In an alternative embodiment of the invention, the at least one discrete power semiconductor component or the plurality of discrete power semiconductor components can be grasped by a gripper and positioned on the power semiconductor component module to be produced in a special arrangement, for example in a circular or star-shaped arrangement. The respective power semiconductor component is then fixed in position by means of a retaining element only during the laser welding. The retaining element can then be removed again. In this case, the retaining element acts only as a temporary retainer during the laser welding.

[0030] The power semiconductor component can be fixed to the holding component by means of adhesive bonding, for example by means of adhesive points on the top side of the power semiconductor component.

[0031] Advantageously, the holding component has a welding window through which the laser welding is performed. This allows for an advantageous coupling of the laser beam from above. At the same time, other areas of the SMD circuit carrier are protected or shielded from damage by the laser beam. In particular, welding residues can be retained here due to the shielding. In addition, the presence of the welding window enables the introduction of insulating material at the welding location or of a casting material, provided that the entire volume can be cast, which is also formed or at least limited by the holding component.

[0032] Furthermore, a pressure contact can be additionally produced between the at least one power semiconductor component and the SMD circuit carrier by means of a retaining component for electrical and thermal contacting in the SMD power semiconductor component module, in that the arrangement comprising the power semiconductor component and the circuit carrier is clamped between the retaining component and a support, preferably a support on the mounting side. The latter can be, for example, a heat sink located on the lower side of the SMD circuit carrier or a support on the mounting side, such as a housing component, with which the power semiconductor component module is mounted in a state of use. Furthermore, due to the use of the retaining component for clamping the corresponding power semiconductor component, the necessity of adapting the shape or design of the power semiconductor component itself, for example, to its pressing in, can be omitted. The power semiconductor component itself does not need to be adapted, but only needs to be placed on the conductor circuit structure of the SMD circuit carrier located on the insulating body. In particular, the pressure contact can be realized, for example, by screwing the retaining component to the heat sink or by pressing the retaining component to the SMD circuit carrier. The pressure contacting produces a reliable electrical and thermal contact between the power semiconductor component and the SMD circuit carrier, which always ensures good electrical and thermal contact even in the event of temperature fluctuations or mechanical influences.

[0033] According to another advantageous embodiment, an elastic element can be arranged between the at least one power semiconductor component and the holding element. This allows the power semiconductor components to be pressed onto the SMD circuit carrier with the same or at least similar force. In addition, this design makes it possible to produce pressure contact by clamping with the holding element even in the case of height differences due to different heights of power semiconductor components.

[0034] Suitably, the elastic element is a silicone foam pad.

[0035] The at least one power semiconductor component, preferably a plurality of power semiconductor components, can first be positioned in a predefined arrangement and / or orientation on a mounting film, preferably a self-adhesive mounting film, and fixed there, wherein the holding part can then be fixed to the at least one power semiconductor component, preferably the plurality of power semiconductor components, in the arrangement and / or orientation predefined on the mounting film. The method according to the invention thus allows the arrangement of power semiconductor components to be produced in advance, for example in batches on a large scale, and then to be transferred to the holding part to be used as a transfer part or to be removed by a gripper. For example, in this way, a variety of arrangements and / or orientations of a plurality of power semiconductor components can be provided on a supply roll for a manufacturing process.

[0036] The film is removed from the holding component after the power semiconductor component has been attached to the holding component to be used as a transfer component.

[0037] Preferably, the film is a self-adhesive film.

[0038] The method according to the invention also makes it possible to implement the power semiconductor component module with a low-inductive wiring plane. In particular, a low-inductive wiring plane enables fast switching. In particular, as an SMD circuit carrier, a multilayer SMD circuit carrier comprising at least a first and a second insulator and a first and a second conductor circuit structure can also be produced within the scope of the method according to the invention, wherein the contact point can be located on the first conductor circuit structure or the second conductor circuit structure. It is also possible to produce a structure comprising more than two insulators or insulation layers.

[0039] The method according to the invention also allows the second insulating body with the second conductor track structure to be arranged laterally to the semiconductor component. Here, laser welding of the connecting element of the power semiconductor component to the laterally arranged second conductor track structure can also be performed in the manner according to the invention.

[0040] In particular, the contact point can be located on the second conductor track structure, wherein the second insulator is bent together with the second conductor track structure and the first conductor track structure is also bent accordingly or in accordance with the second insulator and moved away from the latter. The contact point is located in the region of the second conductor track structure which is arranged parallel to the first insulator.

[0041] In order to fulfill the cooling function under the SMD circuit carrier, a cooler, preferably in the form of a cooling body, can be provided for heat conduction. In particular, a cooling body made of aluminum, preferably pure aluminum, can be provided due to the high thermal conductivity of aluminum. With these cooling devices and conditions, the semiconductor chips contained in the semiconductor component can meet optimized power and reliability requirements.

[0042] Particularly advantageously, the semiconductor components can be designed for a minimum current of 5 V or for a minimum voltage of 24 V. In particular, the method according to the invention is particularly suitable for this range of power electronics, since the laser welding connection allows high temperatures caused by high currents and voltages of the semiconductor components without limiting the power and reliability of the circuit.

[0043] The semiconductor components can be active or passive components. As active and passive semiconductor components, (packaged) discrete power components are used, which can be selected according to the corresponding parameters in accordance with the requirements of the circuit. The semiconductor chips contained therein are constructed in such a way that they meet the optimized power and reliability requirements under given cooling conditions. Other (passive) circuit modules can also be welded or pressure contacted.

[0044] The semiconductor component can have an electrically and thermally conductive base surface, which can be contacted with an SMD circuit carrier or a conductor circuit structure arranged thereon by means of a pressure contact. For this purpose, for example, a surrounding frame of the holding component can be pressed against an edge region of the insulating body. In particular, the holding component can have at least one projection, which engages in a corresponding recess on the edge region of the insulating body for the purpose of pressing, or vice versa. In particular, a locking or snapping-in of the component can also be provided. By pressing or locking or snapping connections, pressure contacts with the required pressure or pressing force can be reliably and continuously produced.

[0045] Advantageously, the electrically and thermally conductive base surface of the semiconductor component can be provided with a coating made of silver or a silver alloy, thereby achieving good ohmic and thermal contact over the long term. Good ohmic contact ensures good current conduction, and good thermal contact leads to good heat conduction and thus corresponding cooling.

[0046] The coating composed of silver or a silver alloy can have a thickness of 0.1 μm to 0.5 μm, in particular 0.1 μm to 0.3 μm.

[0047] The invention furthermore relates to an SMD power semiconductor component module which is produced according to a method according to at least one of claims 1 to 24 . BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Description of the invention by means of examples

[0049] The invention is explained in more detail with reference to an exemplary embodiment in the drawing. Figure 1 :

[0050] Figure 1 A highly simplified schematic diagram shows the provision of a plurality of power semiconductor components in a defined arrangement and / or orientation on a mounting film;

[0051] Figure 2 A greatly simplified schematic diagram shows the transfer of power semiconductor components arranged on a mounting film in the relevant arrangement and / or orientation to a holding component, which in this example serves as a transfer component;

[0052] Figure 3 A greatly simplified schematic diagram shows a laser welding process for connecting connecting elements of a power semiconductor component to contact locations of an SMD circuit carrier in the form of a lead frame;

[0053] Figure 4 Shown after completion according to Figure 3 A strongly simplified schematic diagram of the arrangement of the structure;

[0054] Figure 5A greatly simplified schematic diagram shows a laser during the implementation of a laser welding connection;

[0055] Figure 6 A greatly simplified schematic diagram shows a melting region in the region of a connection element of a power semiconductor component and a contact location of an SMD circuit carrier in a first embodiment;

[0056] Figure 7 shows a greatly simplified schematic representation of a melting region in the region of a connecting element of a power semiconductor component and a contact location of an SMD circuit carrier in another embodiment;

[0057] Figure 8 A highly simplified schematic diagram shows another embodiment of an SMD power semiconductor component module produced by the method according to the invention in the region of a power semiconductor component in the form of a lead frame comprising two insulators;

[0058] Fig. 9 A highly simplified schematic diagram shows another embodiment of an SMD power semiconductor component module produced by the method according to the invention in the region of a power semiconductor component in the form of a lead frame comprising two insulators;

[0059] Fig.10 Shown in accordance with Figure 4 A greatly simplified schematic diagram of an arrangement of the insulating body with a retaining element locked or pressed against the insulating body;

[0060] Fig.11 A greatly simplified schematic diagram shows a further embodiment of an SMD power semiconductor component module produced by the method according to the invention in the region of a power semiconductor component comprising a holding component which has been applied after laser welding has been carried out in order to produce a pressure contact;

[0061] Fig.12 A highly simplified schematic diagram shows another embodiment of an SMD power semiconductor component module produced by the method according to the invention in the region of the power semiconductor component module using elastic elements between the holding component and the power semiconductor component to produce a pressure contact;

[0062] Fig.13 The following is shown with the additional use of elastic elements and retaining components. Fig.10 A greatly simplified schematic diagram of an arrangement of the type shown in FIG. 1 , wherein the holding element is not provided as a transfer element; and

[0063] Fig.14 A greatly simplified schematic diagram of a holding element for ensuring pressure contact for a plurality of power semiconductor components arranged on an SMD circuit carrier is shown. DETAILED DESCRIPTION

[0064] Figure 1 It is shown that in an assembly machine 13, a plurality of power semiconductor components 4 are provided on an assembly film 11 which is not insulated on its underside, the assembly film being unwound from a reel 17 and being wound again on another reel 17 with the power semiconductor components 4 arranged thereon. The power semiconductor components 4 are discrete power semiconductor components which include connection elements 5 in the form of connection legs. Usually, for each power semiconductor component 4, a connection leg is provided for the collector, emitter and gate of the power semiconductor component 4, respectively. The assembly machine 13 comprises a support plate 14, for example of metal. The metal support plate 14 causes electrostatic discharge of the power semiconductor components 4.

[0065] The mounting film 11 is preferably a film which is self-adhesive on one side.

[0066] Therefore, in the process of assembling the power semiconductor components 4 on the mounting film 11, the arrangement and / or orientation of the power semiconductor components 4 as they should be set as needed in the subsequent use can be specified. This involves the arrangement and / or orientation of the power semiconductor components 4 with each other or with each other, which can be pre-produced in batches within the scope of providing a plurality of power semiconductor components 4. For example, a ring-shaped or star-shaped arrangement can be involved here. Large-scale pre-batch production of power semiconductor component groups can be achieved in this way. The grouped power semiconductor components can be provided in roll form together with the mounting film 11.

[0067] According to the method according to the invention, the combination (Zusammenstellung) of the power semiconductor components 4 arranged on the mounting film 11 is transferred to the holding component 9, positioned thereon and fixed. This is carried out on the operating medium plate 15. On the operating medium plate 15, the mounting film 11 is provided together with the power semiconductor components 4 located thereon. On the upper side of the power semiconductor components 4, the adhesive 12 is applied respectively and the holding component 9 is then applied to the upper side of the corresponding power semiconductor component 4 provided with the adhesive 12. The holding component 9 is thereby continuously connected to the pre-mass-produced arrangement of the power semiconductor components 4. The mounting film 11 is then pulled out. The holding component 9 is provided with individual welding windows 8. Preferably, the holding component 9 is a plastic plate or a plate-shaped part of a component for a later use purpose.

[0068] Figure 3 The contacting of a power semiconductor component 4 is shown, which has been connected to a holding component 9, including an SMD circuit carrier 1 in the form of a lead frame using a laser welding connection. Figure 3 Only a partial region of the holding element 9 provided in the production method is shown.

[0069] The lead frame comprises an insulator 2 and a conductor track structure 2a or contact position 3 located on the insulator 2 for contacting with the connecting element 5 of the power semiconductor component 4. The conductor track structure of the lead frame can be punched, etched or laser cut. The corresponding power semiconductor component 4 has a conductive base surface 4a, on which a coating 6 is located. The coating 6 is preferably a coating made of silver or a silver alloy. The coating made of silver or a silver alloy can have a thickness of 0.1 μm to 0.5 μm, in particular 0.1 μm to 0.3 μm.

[0070] Positioned on the underside of the insulating body 2 is a cooler 7 which serves to dissipate thermal energy generated during operation of the power semiconductor components 4 .

[0071] Instead of an SMD circuit carrier 1 in the form of a lead frame, it is also possible to use an SMD circuit carrier in the form of a circuit board or an IMS substrate.

[0072] The arrangement of the power semiconductor components 4 and the holding elements 9 attached thereto is oriented with the SMD circuit carrier 1 in such a way that the connecting elements 5 of the respective power semiconductor components 4 are located at the contact locations 3 of the SMD circuit carrier 1. The connecting elements 5 of the power semiconductor components 4 are preferably designed in a stepped manner and extend parallel to the main extension surface of the SMD circuit carrier 1 in the contact region with the contact locations 3.

[0073] The contact points 3 and the connecting elements 5 are made of copper or a copper alloy. The connecting elements 5 of the power semiconductor components 4 can be provided with a Sn-Ag coating (not shown in the figure). The latter is usually provided as a soldering aid in order to avoid copper oxidation during the soldering process that usually occurs.

[0074] In the context of the method according to the invention, the contact between the connecting element 5 and the contact location 3 is not produced by means of soldering, but by means of laser welding 16 .

[0075] In the process of the method according to the present invention, the power semiconductor component 4 is fastened on the same side of the SMD circuit carrier 1 in an SMD construction mode, and the electrical contact of the connecting element 5 of the power semiconductor component on the SMD circuit carrier 1 is made on the side. Therefore, the mechanical fastening plane and the electrical contact plane are the same or at least parallel to each other on the same side of the SMD circuit carrier 1. Based on the connection of the connecting element 5 with the respectively configured contact position 3 by laser welding 16 instead of the soldering connection, the current carrying capacity of the manufactured SMD power semiconductor component module is significantly improved. In laser welding, the connecting element and the contact position in the relevant area of ​​the laser beam melt, thereby producing a tight connection of the joint part. The connection of a single metal is made differently from soldering by laser welding. This produces an advantage that this type of material-locked connection allows the SMD semiconductor component module to be operated with a higher current intensity, unlike the soldering connection. In addition, the connection according to the present invention also allows the SMD power semiconductor component module to be operated at a higher temperature than the temperature possible during the soldering connection. In addition, compared to the soldering connection, a more durable operation under high load change conditions is possible. This makes it possible to achieve a high reliability of the SMD power semiconductor component module. Finally, it is achieved that the power semiconductor component module can be operated at the full effective power of its power semiconductor components, ie no “limiting” is necessary.

[0076] Due to the holding element 9 arranged on the top side with the welding window 8 formed therein, the laser beam 18 can be advantageously coupled in from above. At the same time, other areas of the SMD circuit carrier 1 are protected or shielded from damage by the laser beam 18, in particular welding residues. In addition, the welding window 8 enables the insulating material 26 (in the Figure 4 The introduction of insulating material 26 in the form of a casting material by pouring the insulating material 26 completely through the cavity at least partially defined by the holding part 9, for example in the form of insulating droplets, in the area of ​​the laser welding. Fig.10 As shown in the example.

[0077] According to a suitable alternative embodiment of the method according to the invention, at least one power semiconductor component, preferably a plurality of power semiconductor components, can be removed from a supply source, for example a correspondingly mounted mounting film 11, in a desired arrangement by a gripper (not shown in the drawings) and arranged on an SMD circuit carrier. Figure 3 The holding component 9 is used for fixing the position of the power semiconductor component 4 during the laser welding process. The holding component 9 does not serve as a transfer component in this case, but is only used for fixing during the laser welding.

[0078] according to Figure 4By means of the holding element 9, a pressure contact can be produced between the power semiconductor component 4 and the SMD circuit carrier 1 for electrical and thermal contacting. This can be done according to Figure 4 This is done by clamping the power semiconductor component 4 with the holding component 9 and the SMD circuit carrier 1. This can be done, for example, by screwing the holding component 9 together with the cooler 7 with the aid of screws 25. Figure 4 For simplicity, only one screw 25 is shown. The entire arrangement comprising the holding element 9, the power semiconductor component 4, the SMD circuit carrier 1 and the cooler 7 can be arranged, for example, on a bearing cap of an electrical device, such as an electric motor. For example, certain electrical consumers or electrical components (such as motor coils) can be directly connected to the SMD power semiconductor component module prepared in this way.

[0079] Alternatively, the holding component 9 can also be pressed against the SMD circuit carrier 1 in order to produce a pressure contact. For this purpose, for example, the surrounding frame 27 of the holding component 9 can be pressed against the edge region 28 of the insulating body 2. By pressing or locking or snapping the connection, a pressure contact with the required pressure or pressing force can be reliably and permanently produced. In particular, a locking or snapping of the components can also be provided (see Fig.10 The clamping connection and / or the locking connection is provided with the reference numeral 29. In particular, the holding element 9 can have at least one (in Fig.10 The projection (not shown) is pressed into or locked or snapped into the edge region 28 of the insulating body 2 (at Fig.10 By means of the pressing, locking and / or snap connection, a pressure contact with the required pressure or pressing force can be reliably and continuously produced.

[0080] Figure 5 A greatly simplified schematic diagram of the embodiment and mode of operation of the laser to be used for producing the laser welded connection 16 is shown. Preferably, this is a so-called fiber laser 22, in which the laser beam 18 is provided via a glass fiber 19. The laser beam 18 can be moved according to the desired intended use by means of a scanner 24. The scanner 24 can ensure that the laser beam 18 is implemented, for example, as in Figure 5 As an alternative or in addition, the laser beam 18 can also perform a swinging motion (WB), as also shown in FIG. Figure 5 As shown in .

[0081] Figure 5 An example of a coupling surface 23 of a laser beam 18 in transient reception during the circular movement KB and during the oscillating movement WB is shown. The laser is preferably an IR laser.

[0082] The laser spot has a diameter in the range of 20-50 μm, in particular 30-40 μm. The melt region 21 created by the laser beam 18 is at least substantially connected, for example point-like or circular. The diameter of the melt region 21 is in the range of 60-100 μm, preferably 70-90 μm.

[0083] Figure 6 The laser welded connection 16 is shown in a greatly simplified schematic diagram and has at least substantially a circular melting region 21. Figure 6 In the figures shown in , the at least substantially punctiform or circular shape of the melt region 21 is determined by the substantially circular cross section of the laser beam 18 .

[0084] exist Figure 7 In the alternative embodiment shown in FIG. 1 , a melting zone 21 is provided which is also at least substantially point or circular. However, the latter is established by a special movement of the laser beam 18, namely by a circular movement KB, see Figure 5 The circular motion can also be superimposed by a swinging motion WB.

[0085] Figure 8 A power semiconductor component module produced according to the method according to the invention is shown in a greatly simplified schematic diagram, which has a low-inductance construction comprising a multi-layer SMD circuit carrier 10 in the form of a multi-layer lead frame. Figure 8 The visible multilayer SMD circuit carrier 10 comprises a first insulating body 2 assigned to the cooler 7 with a punched or cut conductor track structure 2a and contact locations 3, and a second insulating body 20 located thereon and comprising the associated punched or cut conductor track structure 20a. The connecting elements 5 of the power semiconductor components 4 make contact with the contact locations 3 of the conductor track structure 2a. A corresponding design enables particularly fast switching characteristics of the electronic circuit.

[0086] Fig. 9 A further variant of a power semiconductor component module is shown in a greatly simplified schematic diagram, which can be produced according to the method according to the invention. This also involves a multilayer SMD circuit carrier 1 in the form of a multilayer lead frame, which has a first insulating body 2 provided with a conductor track structure 2a, which is connected to a cooler 7, and a second insulating body 20 located thereon and provided with a second conductor track structure 20a, which is designed to be bent. The corresponding connecting elements 5 of the power semiconductor components 4 are contacted with the contact points 3 of the second conductor track structure 20a of the second insulating body 20 by means of laser welding 16.

[0087] exist Figure 8 and9 In the power semiconductor component module shown in , it is possible to use a multilayer printed circuit board or a multilayer IMS substrate instead of an SMD circuit carrier 10 in the form of a multilayer lead frame.

[0088] In addition, two embodiments of the power semiconductor assembly module correspond to Figure 4 Power semiconductor component modules in. Figure 8 The two embodiments of the present invention also include, in the fully mounted state, a holding element 9 arranged on the upper side, with which the already mounted Figure 4 The manner and method of producing a pressure contact is described.

[0089] exist Fig.11 In the embodiment shown in Figure 4 In contrast to the embodiment of the invention, the pressure contact is applied to the power semiconductor component 4 by means of a holding component 90 which does not have a through hole for the laser beam. In this embodiment, the laser welding of the connecting element 5 of the power semiconductor component 4 is performed before the holding component 90 is applied. For example, the laser weld can be produced by using a holding component 9 which is only temporarily provided for fixing the power semiconductor component 4 during the laser welding and includes a welding window 8, which is then removed again. Based on this, in Fig.11 The retaining member 90 shown in FIG. 1 does not require a welded window. Fig.11 The embodiment of the present invention corresponds to Figure 4 implementation plan.

[0090] Fig.12 A further embodiment of the present invention is shown, in which an elastic element 91 is inserted between the holding part 90 and the respective power semiconductor component 4, by means of which a controlled pressure is applied to the power semiconductor component 4 in order to ensure pressure contact. The elastic element 91 is preferably a silicone foam pad. By means of the elastic element 91, a uniform pressing force can be applied to a plurality of power semiconductor components 4 via the holding part 90.

[0091] In the same way, it is also possible that, if a holding part 9 equipped with a welding window 8 is to be used for applying the pressure contact instead of the holding part 90 , a corresponding elastic element 91 can also be present in this case.

[0092] In addition, according to Fig.13 The implementation scheme is shown in accordance with Fig.10 A possible variant of the embodiment of the invention is that, on the one hand, an elastic element 91 is arranged between a holding component 90 and a power semiconductor component 4, in which the ... Fig.10 There is no welding window. Fig.10In an embodiment of the present invention, an elastic element 91 is present.

[0093] Fig.14 A holding component 90 is shown in which a plurality of elastic elements 91 are provided for a plurality of (in Fig.14 The pressure of the power semiconductor components (not shown) can be applied to each power semiconductor component. Fig.14 The holding element 90 of the embodiment of FIG. 1 can be mechanically coupled to the heat sink 7 or the insulating body 2 of the SMD circuit carrier 1 in the manner already described above.

[0094] In the aforementioned embodiment, the SMD circuit carrier may also be as in Figure 8 and 9 The SMD circuit carrier illustrated by way of example in FIG.

[0095] The method according to the invention is very particularly suitable for power semiconductor component modules with a minimum current intensity of 5 V or for a minimum voltage of 24 V. In particular for this range of power electronics, the method according to the invention is particularly suitable because the laser welded connection 16 allows the high temperatures caused by the high current intensity and voltage of the semiconductor components 4 and does not limit the power and reliability of the circuit.

[0096] The semiconductor component 4 can be an active or passive semiconductor component. As active and passive semiconductor components, (packaged) discrete power semiconductor components are used, which can be selected according to the corresponding parameters in accordance with the requirements of the circuit. The semiconductor chips contained therein are configured in such a way that they meet the optimized power and reliability requirements under given cooling conditions. Preferably, they are standard semiconductor components, which include electrical contact surfaces on their underside, which are provided for SMD technology.

[0097] Reference numerals list

[0098] 1SMD circuit carrier

[0099] 2 (First) Insulator

[0100] 2a (First) Conductor Circuit Structure

[0101] 3 contact positions

[0102] 4 Power semiconductor components

[0103] 4a Conductive base surface

[0104] 5. Connecting elements

[0105] 6. Cladding

[0106] 7 Cooler

[0107] 8 welding window

[0108] 9. Keeping components

[0109] 10SMD circuit carrier

[0110] 11 Assembly film

[0111] 12 Adhesive

[0112] 13Assembly machine

[0113] 14Metal bracket plate

[0114] 15 Running medium board

[0115] 16Laser welding department

[0116] 17 reels

[0117] 18 Laser beams

[0118] 19 Fiberglass

[0119] 20 Second Insulator

[0120] 20a Second conductor circuit structure

[0121] 21 Melting Area

[0122] 22 Fiber Laser

[0123] 23 coupling surface

[0124] 24 Scanner

[0125] 25 screws

[0126] 26 Insulation Materials

[0127] 27 Frames

[0128] 28 Edge Area

[0129] 29 card lock connection

[0130] 90 Holding parts

[0131] 91 Elastic Components

[0132] KB circular motion

[0133] WB Swing Movement

Claims

1. A method for manufacturing an SMD power semiconductor component module, the method comprising the following steps: An SMD circuit carrier (1, 10) provided with contact locations (3) and an insulating part is provided. Providing at least one discrete power semiconductor component (4) provided with an electrically conductive connecting element (5), preferably a connecting leg, The at least one discrete power semiconductor component (4) provided with an electrically conductive connecting element (5) is arranged on the side of the SMD circuit carrier (1, 10) provided with the contact location (3), wherein: The connecting element (5) of the power semiconductor component (4) makes contact with the contact point (3) of the SMD circuit carrier (1, 10), and The connecting element (5) is connected to the respectively assigned contact positions (3) by laser welding.

2. The method according to claim 1, characterized in that A printed circuit board, an IMS substrate or a lead frame is provided as the SMD circuit carrier (1).

3. The method according to claim 1 or 2, characterized in that The contact point (3) and / or the connecting element (5) comprises copper or a copper alloy.

4. The method according to at least one of the preceding claims, characterized in that The connecting element (5) is designed to extend parallel to a main extension area of ​​the SMD circuit carrier (1, 10) in the region of the connecting element (5) where the laser welding takes place.

5. The method according to at least one of the preceding claims, characterized in that The connecting leg is designed to be stepped.

6. The method according to at least one of the preceding claims, characterized in that The laser welded connection is formed by means of connected melt zones (21).

7. The method according to at least one of the preceding claims, characterized in that The laser welding connection is carried out by means of an oscillating laser beam.

8. The method according to at least one of the preceding claims, characterized in that The laser welding is performed using an IR laser.

9. The method according to at least one of the preceding claims, characterized in that The at least one discrete power semiconductor component (4), preferably a plurality of power semiconductor components (4), provided with electrically conductive connecting elements (5), is located between the SMD circuit carrier (1, 10) and the holding component (9, 90).

10. The method according to claim 9, characterized in that The at least one discrete power semiconductor component (4), preferably the plurality of power semiconductor components (4), which is provided with an electrically conductive connecting element (5), is positioned and fixed on the holding component (9, 90) before the laser welding, or the holding component (9, 90) is placed on the at least one discrete power semiconductor component (4), preferably the plurality of power semiconductor components (), which is provided with an electrically conductive connecting element (5) for positional fixation before the laser welding.

11. The method according to claim 9 or 10, characterized in that The holding component (9) has a welding window (8) through which the laser welding is performed.

12. The method according to at least one of the preceding claims, characterized in that In addition, pressure contacts are produced between the at least one power semiconductor component (4) and the SMD circuit carrier (1, 10) for electrical and thermal contact-making.

13. The method according to claim 12, characterized in that The pressure contact is produced by the holding element (9, 90) in that the arrangement comprising the power semiconductor component (4) and the SMD circuit carrier (1, 10) is clamped between the holding element (9, 90) and a support, preferably a mounting-side support.

14. The method according to claims 9 to 13, characterized in that An elastic element (91) is arranged between the at least one power semiconductor component (4) and the holding element (9, 90).

15. The method according to claim 14, characterized in that The elastic element (91) is a silicone foam pad.

16. The method according to claims 9 to 15, characterized in that The at least one power semiconductor component (4), preferably a plurality of power semiconductor components (4), is first positioned in a predetermined arrangement and / or orientation on a preferably self-adhesive mounting film (11), fixed there, and the retaining element (9) is fixed to the at least one power semiconductor component (4), preferably a plurality of power semiconductor components (4), in a predetermined arrangement and / or orientation on the mounting film (11).

17. The method according to at least one of the preceding claims, characterized in that A multilayer SMD circuit carrier (10) is provided as an SMD circuit carrier (10) comprising at least a first and a second insulator (2, 20) and a first and a second conductor circuit structure (2a, 20a), wherein the contact point (3) is located on the first conductor circuit structure (2a) or the second conductor circuit structure (20a).

18. The method according to claim 17, characterized in that The second insulating body (20) together with the second conductor track structure (20a) is arranged laterally to the semiconductor component (4).

19. The method according to claim 18, characterized in that The contact point (3) is located on the second conductor circuit structure (20a), The second insulator (20) is bent together with the second conductor circuit structure (20a), and The connection of the connecting element (5) to the respectively assigned contact point (3) is carried out by laser welding in a region of the second conductor track structure (20a) arranged parallel to the first insulating body (2).

20. The method according to at least one of the preceding claims, characterized in that The SMD circuit carrier (1, 10) comprises a cooling function, preferably in the form of a cooler (7).

21. The method according to at least one of the preceding claims, characterized in that The power semiconductor component (4) is designed for a minimum current intensity of 5V or for a minimum voltage of 24V.

22. The method according to at least one of the preceding claims, characterized in that The power semiconductor component (4) is an active or passive semiconductor component.

23. The method according to at least one of the preceding claims, characterized in that The power semiconductor component (4) has an electrically and thermally conductive base surface (4a) which is contact-connected to the SMD circuit carrier (1, 10), preferably by means of pressure contact.

24. The method according to claim 23, characterized in that The electrically and thermally conductive base surface (4a) is provided with a coating made of silver or a silver alloy.

25. An SMD power semiconductor component module produced according to a method according to at least one of the preceding claims.

Images