Abstract:
A device with power semiconductor components controlling the power of high currents has each power semiconductor component insulated and fixed to a common cooled carrier body. Conductor bars, in addition to the power semiconductor components, are fixed to the carrier body, the conductor bars being electrically insulated and placed on top of each other, whereby each semiconductor bar has a free contact surface, and one electrical contact surface of each semiconductor component is electrically connected to a conductor bar by one or several electric conductor bridges and another electrical contact surface of the power semiconductor component is electrically connected to another bar conductor by one or several conductor bridges.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an arrangement with one or more power semiconductor components for high current power control. 
     DESCRIPTION OF THE RELATED ART 
     In automobile engineering, an increasing number of functions are controlled by electrical means. For example, the starter and generator may be combined into a single unit. The power supply of such systems requires more powerful supply units which, because of their large thermal dissipations, require active cooling which is provided e.g. by the circulation of cooling water. 
     In extreme cases the cooling water temperature can reach 125° C., which means that only a very small temperature variation is possible for all the electrical components. Because of the low vehicle electrical system voltage of only 14–42 V, very large currents and therefore short paths to the load are necessary. Consequently the control units must be installed close to the engine which constitutes a hot, high vibration environment. 
     Arrangements incorporating one or more power semiconductor components for high current power control are generally of modular design. The power semiconductor components or semiconductor switches are mounted on substrates, mainly metallized ceramic plates, in an electrically isolating manner. These sub-units are fixed to a supporting structure in the form of a coolable base plate. The supply leads are routed from the substrates to pins in a package frame and ultimately to the top of the package by means of soldered-on metal links, spring contacts or bonds. Power is then supplied above the package by means of a busbar or a circuit board. This means that no space is needed on the base plate for a busbar and the size can be kept small. 
     As some of the electrical connection parts are now far above the base plate, they may oscillate severely in the event of vibrations and quickly fatigue the connection to the substrate. 
     Designs are also known whereby the supply leads for the positive electrical pole “+” and the negative electrical pole “−” are routed in antiparallel one above the other in an electrically isolated manner (see e.g. EP 585578 A1 or Mitsubishi) or additionally routed directly via substrates (see e.g. U.S. Pat. No. 5,574,312 of ABB Management AG) in order to minimize the inductance of the arrangement. Reservoir capacitors are also disposed in a low inductance manner on the free side of the busbar (see e.g. WO 9 5504 448 of KAMAN ELECTROMAGNETICS CORP.) or a heat sink is itself used as a current-carrying part (see e.g. EP 443378 A of REHM SCHWEISSTECHNIK GmbH &amp; Co.). 
     SUMMARY OF THE INVENTION 
     The object of the invention is generally to provide an arrangement with one or more power semiconductor components for high current power control and having a long service life in a high vibration environment. 
     This object is achieved by an arrangement with one or more power semiconductor components for high current power control, having the features set forth below. 
     According to this solution, in the arrangement according to the invention incorporating one or more power semiconductor components for high current power control,
         each power semiconductor component is mounted in an electrically isolating manner on a surface of a common supporting structure and has at least two electrical terminal lands disposed separately from one another,   two or more conductor bars disposed separately from one another being fixed to the surface of the supporting structure adjacently to the power semiconductor component(s) and electrically isolated from each power semiconductor component, and   an electrical terminal land of each power semiconductor component being electrically connected to one of the conductor bars by one or more electrical bridging links and another electrical terminal land of each power semiconductor component being electrically connected to the other of the conductor bars by one or more electrical bridging links.       

     In the arrangement according to the invention, the conductor bars and likewise the power semiconductor components can advantageously be disposed in close proximity to one another directly on the surface of the supporting structure. This means that the oscillations of the conductor bars and power semiconductor components against one another advantageously remain negligibly small. Moreover, because of the conductor bars and power semiconductor components being disposed in close proximity to one another, advantageously short electrical bridging links are used, having natural frequencies such that they are unlikely to be excited to resonance during normal operation of the arrangement according to the invention in a high vibration environment. For these reasons the arrangement according to the invention is excellently suited for long-term use in a high vibration environment, particularly in the vicinity of a prime mover, e.g. an internal combustion engine of a motor vehicle, which moreover constitutes a hot environment. 
     With the arrangement according to the invention, the power semiconductors advantageously do not need to be encapsulated, but are preferably mounted bare on the supporting structure. Only the arrangement as a whole must be hermetically sealed in a package. 
     Preferred and advantageous embodiments of the arrangement according to the invention are detailed below. 
     Some embodiments include the conductor bars disposed one above the other are advantageous for a particularly compact design of the arrangement according to the invention. 
     As already mentioned, a preferred and advantageous application of the arrangement according to the invention is its use in a motor vehicle engine compartment and in particular, but not exclusively there, for supplying an electrical load of a motor vehicle. 
     An electrical load of a motor vehicle is taken to mean, for example and among other things : a starter/generator, particularly comprising a starter motor and a generator, an electric active suspension system, an electric power-assisted steering system, an electric water pump, an electric oil pump, an air conditioning system of a motor vehicle, etc. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following description the invention will be explained in greater detail with reference to the drawings in which: 
         FIG. 1  shows a perspective view of an exemplary embodiment of the arrangement according to the invention with conductor bars disposed adjacently to one another, 
         FIG. 2  shows a perspective view of another exemplary embodiment of the arrangement according to the invention with conductor bars disposed one above the other, 
         FIG. 3  shows a vertical section through part of the embodiment according to  FIG. 2  along the line III—III in  FIG. 2 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the exemplary embodiments of the arrangement according to the invention as shown in  FIG. 2 , each power semiconductor component  1  is mounted in an electrically isolated manner on a surface  20  of a common supporting structure  2  forming e.g. a base plate. 
     In the embodiment according to  FIG. 1 , by way of example six rows  10  of four power semiconductor components  1  are disposed on the surface  20 . 
     In the other embodiment according to  FIG. 2 , by way of example only two power semiconductor components  1  are shown for the sake of clarity. In this other embodiment the number of power semiconductor components  1  could also be greater than two, e.g. as many as in the embodiment according to  FIG. 1  and e.g. have the same arrangement as there. 
     In general the number of power semiconductor components  1  can be any natural number, i.e. also one, and the figure likewise has an upper limit for technical reasons. 
     Each power semiconductor component  1  has at least two electrical terminal lands  11 ,  11  disposed separately from one another, at least one of which is disposed, for example, on a side of the power semiconductor component  1  facing away from the relevant surface  20  of the supporting structure  2  and the other on a side of said power semiconductor component  1  facing towards the surface  20  and not directly visible in  FIGS. 1 and 2 . 
     On the surface  20  of the supporting structure  2  in each of the two embodiments shown, a plurality of conductor bars  3  disposed separately from one another are mounted adjacently to the power semiconductor components  1  and electrically isolated from each power semiconductor component  1 . 
     Likewise in each of the embodiments shown, one electrical terminal land  11  of each power semiconductor component  1  is electrically connected by one or more electrical bridging links  4  to one of the conductor bars  3 , and the other electrical terminal land  11  of said power semiconductor component  1  is electrically connected by one or more electrical bridging links  4  to another of the conductor bars  3 . 
     In particular, in each of the embodiments shown, an electrical terminal land  11  of one power semiconductor component  1  is electrically connected by one or more bridging links  4  to a conductor bar  3  assigned to one “−” electrical pole, an electrical terminal land  11  of another power semiconductor component  1  is electrically connected by one or more bridging links  4  to another conductor bar  3  assigned to the other “+” electrical pole opposite to the “−” electrical pole, and the other electrical terminal land  11  of one power semiconductor component  1  and the other terminal land  11  of the other power semiconductor component  1  are electrically connected by one or more bridging links  4  to another conductor bar  3 . 
     For example, in the embodiments according to  FIGS. 1 and 2  the configuration is preferably such that each power semiconductor component  1  is implemented as a switching or control element wherein a current dependent on the switching or control state of the component  1  flows or does not flow between its one terminal land  11  and its other terminal land  11 , and that the power semiconductor component  1  connected with one terminal land  11  to the conductor bar  3  assigned to one “−” pole and the power semiconductor component  1  connected with one terminal land  11  to the other conductor bar  3  assigned to the other “+” pole are switched or controlled in a push-pull manner, i.e. a component  1  is switched off or on while the other is switched on or off and vice versa. The other conductor bar  3  connected to the other terminal land  11  of each of these two power semiconductor components  1  forms in this case specifically a phase conductor bar which is additionally identified as “N” in  FIGS. 1 and 2 . 
     The embodiment according to  FIG. 1  is implemented for example in such a way that all the conductor bars  3  are disposed adjacently and parallel to one another on the surface  20  of the supporting structure  2 . 
     Specifically the configuration for this embodiment is such that
         between a first conductor bar  3  located farthest right in  FIG. 1  and assigned to the “+” pole and a first phase conductor bar  3  on the left adjacent thereto and designated “N” there is disposed a first row  10  of four power semiconductor components  1 ,   between the first phase conductor bar  3  and a first conductor bar  3  on the left adjacent thereto and assigned to the “−” pole there is disposed a second row  10  of four power semiconductor components  1 ,   between the first conductor bar  3  assigned to the “−” pole and a second phase conductor bar  3  on the left adjacent thereto and designated “N” there is disposed a third row  10  of four power semiconductor components  1 ,   between the second phase conductor bar  3  and a second conductor bar  3  on the left adjacent thereto and again assigned to the “+” pole there is disposed a fourth row  10  of four power semiconductor components  1 ,   between the second conductor bar  3  assigned to the “+” pole and a third phase conductor bar  3  on the left adjacent thereto and designated “N” there is disposed a fifth row  10  of four power semiconductor components  1 , and   between the third phase conductor bar  3  and a second conductor bar  3  on the left adjacent thereto and again assigned the “−” pole there is disposed a sixth row  10  of four power semiconductor components  1 .       

     Two oppositely disposed power semiconductor components  1  of two adjacent rows  10  between which there is disposed a phase conductor bar  3  designated “N” are mutually assigned and form a pair of power semiconductor components  1  connected in a push-pull configuration. 
       FIG. 1  highlights two such pairs of mutually assigned power semiconductor components  1  by showing their power semiconductor components  1  as being connected to the relevant conductor bars  3  by individual electrical bridging links  4 . For example, a bridging link  4  connects each paired component&#39;s electrical terminal land  11  facing the surface  20  of the supporting structure  2  to one conductor bar  3 , and another bridging link  4  connects the electrical terminal land  11  facing away from the surface  20  to the other conductor bar  3 . In a practical embodiment, each individual bridging link  4  is preferably implemented by a plurality of such links  4 , e.g. as indicated in  FIG. 2 . 
     Each conductor bar  3  is preferably implemented from a material of good electrical conductivity, e.g. copper, and having a cross section large enough to handle the specified high current density. 
     Whereas the phase conductor bars  3  designated “N” are formed by individual bars, it is advisable to interconnect the conductor bars  3  assigned to the “+” pole by means of a common conductor bar  33 . The common conductor bar  33  is preferably a plate made of a material of good electrical conductivity disposed on the surface  20  of the supporting structure  2  and from which the conductor bars  3  assigned to the “+” pole project as comb-tooth-like bars, the plate and the bars preferably forming a single piece. 
     The conductor bars  3  assigned to the “−” pole are also preferably interconnected by a common conductor bar which, like the conductor bars  3  assigned to the “−” pole must be electrically isolated from the conductor bars assigned to the “+” pole and from the common conductor bar  33 . 
     In contrast to the embodiment according to  FIG. 1 , in the embodiment according to  FIG. 2  the conductor bars  3  are disposed one above the other and electrically isolated from one another on the surface  20  of the supporting structure  2 , and each of these conductor bars  3  has a free terminal land  30  which is connected by in particular a plurality of electrical bridging links  4  to an electrical terminal land  11  of at least one power semiconductor component  1 . This allows in particular a more compact constructional design of the arrangement according to the invention. 
     In this embodiment it is possible in particular to dispose each pair of mutually assigned power semiconductor components  1 , which are switched or controlled in a push-pull relationship to one another as defined above, on one and the same side of all the conductor bars  3 , in contrast to the embodiment according to  FIG. 1  in which the power semiconductor components  1  of any such pair are disposed on both sides of a phase conductor bar  3  and also flanked by conductor bars  3  assigned to poles different from one another. 
     In the embodiment according to  FIGS. 2 and 3 , a single pair of such power semiconductor components  1  is disposed, for example, on the right-hand side of the stacked conductor bars  3 . However, there are preferably disposed on this right-hand side, although not shown, two or more pairs of mutually assigned power semiconductor components  1  in series along the stacked conductor bars  3  and connected to said conductor bars  3  in the same way as the pair of power semiconductor components  1  shown in  FIG. 2 . 
     Moreover, such pairs of mutually assigned power semiconductor components  1  can also be disposed in series on the left-hand side of the stacked conductor bars  3  facing away from the right-hand side and connected to the stacked conductor bars  3  in a similar manner to the pair of power semiconductor components  1  shown in  FIG. 2 . 
     For example, the power semiconductor devices  1  of the pair shown in  FIG. 2  are connected to the stacked conductor bars  3  in such a way that
         an electrical terminal land  11  of one power semiconductor device  1  of the pair, said terminal land facing away from the surface  20  of the supporting structure  2 , is electrically connected by a plurality of bridging links  4  to the conductor bar  3  disposed, for example, directly on the surface  20  of the supporting structure  2  and assigned to the “−” pole,   an electrical terminal land  11  of the other power semiconductor device  1  of the pair, said terminal land facing the surface  20  of the supporting structure  2 , is electrically connected by a plurality of electrical bridging links  4  to the conductor bar  3  assigned to the “+” pole and disposed, for example, on the conductor bar  3  assigned to the “−” pole and separated from this conductor bar  3  by a layer  32  of electrically isolating material,   the other electrical terminal land  11  of one power semiconductor device  1  of the pair, said surface facing the surface  20  of the supporting structure  2 , is electrically connected by a plurality of electrical bridging links  4  to the phase conductor bar  3  designated “N” and disposed, for example, on the conductor bar  3  assigned to the “+” pole and separated from this conductor bar  3  by a layer  32  of electrically isolating material, and   the other electrical terminal land  11  of the other power semiconductor device  1  of the pair, said terminal land facing away from the surface  20  of the supporting structure  2 , is electrically connected by a plurality of bridging links  4  to this phase conductor bar  3 .       

     A free terminal land  30  of a conductor bar  3  of the stacked or vertically disposed conductor bars  3  is formed, for example, by a surface  300  of said conductor bar  3 , said surface extending beyond another conductor bar  3  disposed on the first conductor bar  3 , said surface  300  having a margin edge  31  over which is routed each individual bridging link  4  electrically connecting the free terminal land  30  of the first conductor bar  3  to an electrical terminal land  11  of a power semiconductor component  1 . 
     Laterally adjacent to the conductor bars  3  disposed one above the other, electrical intermediate terminal lands  5  are disposed on the surface  20  of the supporting structure  2  in an electrically isolated manner and separately from each conductor bar  3 , each of said intermediate terminal lands being electrically connected to a terminal land  11  of one or more power semiconductor components  1  and electrically connected in each case by a plurality of bridging links  4  to a conductor bar  3 . 
     In the embodiment according to  FIG. 2 and 3  there is provided, for example, for each power semiconductor component  1  an intermediate terminal land  5  which is in direct electrical contact with the terminal land  11  of this power semiconductor component  1  facing the surface  20  of the supporting structure  2  and which is fixed to said terminal land. 
     In the embodiment according to  FIG. 2 and 3  there is also provided, for example, an intermediate terminal land  5  which is electrically isolated from the terminal lands  11  of the power semiconductor components  1  but which is electrically connected by a plurality of bridging links  40  to the terminal land  11  of a power semiconductor component  1  facing away from the surface  20  of the supporting structure  2 . 
     Specifically the configuration for the embodiment according to  FIGS. 2 and 3  is such that
         each of the two mutually assigned power semiconductor components  1  is disposed on an electrical intermediate terminal land  5  assigned to said power semiconductor component  1  so that the terminal land  11  of said power semiconductor component  1  facing the surface  20  of the supporting structure  2  and said assigned intermediate terminal land  5  are in direct electrical contact with one another,   an intermediate terminal land  5  assigned to a power semiconductor component  1  is electrically connected by preferably a plurality of electrical bridging links  4  to a conductor bar  3  assigned to an electrical pole, e.g. to the “+” pole,   the terminal land  11  of this power semiconductor component  1  facing away from the surface  20  of the supporting structure  2  is electrically connected by preferably a plurality of electrical intermediate bridging links  40  to the intermediate terminal land  5  assigned to the other power semiconductor component  1  and in turn electrically connected by preferably a plurality of electrical bridging links  4  to the phase conductor bar  3  designated “N”, and   the terminal land  11  of the other power semiconductor component  1  facing away from the surface  20  of the supporting structure  2  is electrically connected by preferably a plurality of electrical intermediate bridging links  40  to an intermediate terminal land  5  electrically isolated from the terminal lands  11  of the power semiconductor components  1  and electrically connected by preferably a plurality of electrical bridging links  4  to the conductor bar  3  assigned to the other electrical pole, e.g. to the “−” pole.       

     Each intermediate terminal land  5  preferably has a margin edge  51  over which each electrical bridging link  4  or  40  connected to said intermediate terminal land  5  is routed. 
     Such electrical intermediate terminal lands  5  can, although not shown, equally well be provided in the embodiment according to  FIG. 1  where, for example, the power semiconductor components  1  of one or each row  10  can be disposed on a common intermediate terminal land  5  in such a way that a terminal land  11  of each power semiconductor component  1  facing the surface  20  of the supporting structure  2  is in direct electrical with said common intermediate terminal land  5 , and the intermediate terminal land  5  can be connected by one or more electrical bridging links  4  to one of the two conductor bars  3  between which said row  10  is disposed. 
     An electrical intermediate terminal land  5  electrically isolated from the electrical terminal lands  11  of the power semiconductor components  1  and electrically connected on the one hand by one or more electrical bridging links  4  to said conductor bar  3  and on the other hand by one or more electrical intermediate bridging links to a terminal land  11  of a power semiconductor component  1  facing away from the surface  20  of the supporting structure  2  can also be disposed, for example, between a conductor bar  3  and an adjacent row  10  of power semiconductor components  1 . 
     The surface  20  of the supporting structure  2  is preferably electrically conducting, and each power semiconductor component  1  and each electrical intermediate terminal land  5  is, as shown in  FIG. 2 , electrically isolated from said surface  20  by a layer  6  of electrically isolating material on the electrically conducting surface  20  of the supporting structure  2 . The layer  6  can be, for example, a DCB ceramic substrate. 
     In the embodiment according to  FIGS. 2 and 3 , for example, all the power semiconductor components  1  and all the intermediate terminal lands  5  are mounted on a common layer  6  of electrically isolating material. Also in the embodiment according to  FIG. 1 , the power semiconductor components  1  of each row  10 , even if not specifically shown, and in said row  10  any intermediate terminal lands  5  provided, are mounted on a common layer  6  of electrically isolating material. 
     The electrically conducting surface  20  of the supporting structure  2  is preferably assigned to an electrical pole, and a conductor bar  3  assigned to said electrical pole is preferably connected directly to said surface  20 , the conductor bar  3  directly connected to the surface  20  being definable by said surface  20  itself. 
     In the embodiment according to  FIGS. 2 and 3  the electrically conducting surface  20  of the supporting structure  2  is assigned, for example, to the “−” pole, and the lowest conductor bar  3  assigned to said “−” pole is directly mounted on the electrically conducting surface  20  of the supporting structure  2 . It could also be formed by the electrically conducting surface  20  of the supporting structure  2  itself. 
     In the embodiment according to  FIG. 1  it is likewise assumed, for example, that the electrically conducting surface  20  of the supporting structure  2  is assigned to the “−” pole, and that each conductor bar  3  assigned to said “−” pole is mounted directly on the electrically conducting surface  20  of the supporting structure  2  or is formed by said electrically conducting surface  20  of the supporting structure  2  itself. The other conductor bars  3  electrically isolated from the conductor bars  3  assigned to the “−” pole and from one another, i.e. the conductor bars  3  assigned to the “+” pole and the phase conductor bars  3  designated “N”, must be electrically isolated from the electrically conducting surface  20  of the supporting structure  2 , e.g. by a layer of electrically isolating material such as that provided by a layer  32  as shown in the embodiment according to  FIGS. 2 and 3 . 
     If cooling is provided, an individual conductor bar  3  can advantageously consist of a thin metal sheet even at high currents of hundreds of amperes in a hot, high vibration environment up to 165° C. 
     On the surface  20  of the supporting structure  2  there is mounted a circuit board  7  of electrically isolating material on which at least one driver circuit  8  and one or more electrical terminal lands  71  are mounted, each terminal land  71  of the circuit boards  7  being connected by a least one electrical bridging link  41  to a terminal land  12  of a power semiconductor component  1 , said terminal land preferably being a control terminal land of said component  1 . 
     In  FIG. 1 , three circuit boards  7  are adjacently disposed, for example, on a common conductor bar  33  and each board is assigned to a phase conductor bar  3  designated “N”. The driver circuit  8  of the circuit board  7  is shown only on the middle circuit board  7  by way of indication. Even though not shown, in reality one such driver circuit is present on each of the other two circuit boards  7 . Also not shown in  FIG. 1  for simplicity&#39;s sake are the terminal lands present on each circuit board  7  and corresponding to the terminal lands  71  of the circuit board  7  in  FIG. 2 , and the terminal lands present on each power semiconductor component  1  and corresponding to the terminal lands  12  in  FIG. 2 . 
     One of these terminal lands of each circuit board  7  in  FIG. 1  is electrically connected by an electrical bridging link  41  to its corresponding terminal land on the first power semiconductor component  1  of the row  10  on one side of the phase conductor bar  3  to which this circuit board  7  belongs, and the other terminal land of this circuit board  7  is connected by an electrical bridging link  41  to its corresponding terminal land on the first power semiconductor component  1  of the row  10  on the other side of said phase conductor bar  3 . In each pair of such rows  10 , the mutually corresponding terminal lands of adjacent power semiconductor components  1  are in each case electrically connected by a bridging link  41  of which only is shown in  FIG. 1 . In each pair of such rows  10 , for example, all the power semiconductor components  1  of a row  10  are switched or controlled in push-pull with all the power semiconductor components  1  of the other row  10  and vice versa. 
     An electrical bridging link  4 ,  40  and/or  41  can consist of a bond wire consisting in particular of a welded fillet or a soldered link. When using bond wires or fillets for the bridging links  4 ,  40 , it is advisable, because of the small cross section, to use two or more such wires or fillets, as shown in  FIG. 2 , for the electrical power connection of an individual terminal land  11  of a power semiconductor component  1  to an intermediate terminal land  5  or a conductor bar  3  and likewise for the electrical power connection of an individual intermediate terminal land  5  to a conductor bar  3 . A soldered link, on the other hand, can be implemented with a very large cross section, so that an electrical power connection can be established using an individual soldered link of this kind. 
     To cool the arrangement, the supporting structure  2  is linked to a heat sink  9  preferably having a cooler  90  which is thermally connected to the supporting structure  2  under the surface  20  of said supporting structure  2 . The cooler  90  is preferably incorporated in the supporting structure  2 . 
     In an exemplary arrangement according to the invention disposed in close proximity to a hot, strongly vibrating internal combustion, a conductor bar  3  and a surface  20 ′ of the supporting structure  2  facing away from the surface  20  of the supporting structure  2  are clamped together by a clamping device  100  gripping around the supporting structure  2  and made of electrically conducting material through which current can be conducted to or from the conductor bar  3 . 
     There is additionally disposed, e.g. on the surface  20 ′ of the supporting structure  2  facing away from the surface  20  of the supporting structure  2 , a capacitor  110  having two electrodes  111  and  112  isolated from one another by a dielectric  113 , of which one electrode  111  is assigned to one of the opposite electrical poles, e.g. the “−” pole in the embodiments shown in the Figures, and is in surface contact with the surface  20 ′ of the supporting structure  2  facing away from the surface  20 , and the other electrode  112  is assigned to the other electrical “+” pole. 
     The electrode  111  of the capacitor  110  which is in surface contact with the surface  20 ′ of the supporting structure  2  facing away from the surface  20  and which is assigned e.g. to an electrical “−” pole is electrically connected to a conductor bar  3  which is assigned to this electrical “−” pole, the other electrode  112  of the capacitor  110  being electrically connected to a conductor bar  3  which is assigned to the electrical “+” pole. 
     A preferred and advantageous use of the arrangement according to the invention is in an engine compartment of a motor vehicle and in particular its use in that location for supplying an electrical load of a motor vehicle, the term “load” being taken to mean the motor vehicle equipment already mentioned above. 
     In a preferred embodiment of the arrangement according to the invention for such an application, the one or more electrically isolating layers  6  with the power semiconductor components  1  mounted thereon are built up on the surface  20  of the supporting structure  2  implemented in the form of a base plate. For example, a layer  6  of electrically isolating material is used whose flat sides facing away from one another are coated with metal, said layer  6  lying flat on the electrically conducting surface  20  of the supporting structure  2  with one of the metal-coated flat sides and being soldered to said surface  20 , whereas, on the other metal-coated flat side of said layer  6  facing away from the surface  20 , one or more of the power semiconductor components  1  are soldered to a terminal land  11  lying flat thereon and separation channels are patterned in the metal coating of said other flat side for forming intermediate terminal lands  5 . 
     The supporting structure  2  can also already contain the integrated cooler  90  which incorporates channels  91  for circulating a coolant. The supporting structure consists of metal, for example, and is electrically conducting. It can additionally be used as the “−” pole. The conductor bars  3  in the form of thin metal sheets are adhesively attached directly adjacent to the substrate or substrates  6  in an isolating manner to the surface  20  of the supporting structure  2  or soldered to the conductor bar  3  right at the bottom for the “−” pole. The contacting to the substrate or substrates in the form of electrically isolating layers  6  is accomplished by a plurality of short bridging links  4  in the form of bond wires, welded fillets or soldered links. The driver circuits  8  for the power semiconductors, preferably MOSFETs, can likewise be integrated adjacent to the electrically isolating layers  6  on the supporting structure  2 . 
     Because of the high ripple current, the capacitor  110  constituting a reservoir capacitor develops non-negligible losses in the form of heat which must be dissipated because of the already very high ambient temperature. For this purpose the capacitor  110  is brought into thermal contact with the back of the cooler  90 , e.g. by adhesively attaching or press-fitting to an electrode  112  to be used as + pole and in contact over its entire surface, in the embodiment according to  FIGS. 2 and 3 , with a cover  60  of electrically conducting material which lies with one edge  61  resting against a layer  34  of electrically isolating material which is mounted adjacent to the electrode  111  of the capacitor  110  assigned to the “−” pole on the surface  20 ′ of the supporting structure  2  facing away from the surface  20  and facing towards the capacitor  110 . 
     The electrode  111  for the “−” pole of the capacitor  110  is in direct planar contact with the surface  20 ′ of the supporting structure  2  facing the capacitor  110 . An electrically conducting connection with a conductor bar  3  assigned to the “+” pole and to a cable lug  103  of a connecting cable is established by a clamping device  100  which can have, for example, for connection to the “+” pole, an electrically conducting screw clamp  101  isolated from the supporting structure  2  and the electrode  111  of the capacitor  110  assigned to the “−” pole and having a handle  102  of electrically isolating material for manual access, said clamp gripping around the supporting structure  2  with the cooler  90  and pressing the capacitor  110  by the cover  60  against the supporting structure  2 . 
     In the embodiment according to  FIGS. 2 and 3 , a clamping device  100  can also be implemented as in the embodiment according to  FIG. 1 . In this embodiment the clamping device  100  has a plurality of clamps  101  each of which grips around the supporting structure  2  and the capacitor  110  of one surface  20  of the supporting structure  2  up to the electrode  112  of the capacitor  110  assigned to the “+” pole. A clamp  101  assigned to the “+” pole is electrically conducting, contacts the electrode  112  of the capacitor  110  assigned to said “+” pole and a conductor bar  3  assigned to said “+” pole or the common conductor bar  33  and is electrically isolated from the supporting structure  2  and the electrode  111  of the capacitor  110  assigned to the “−” pole. For example, two such electrically conducting clamps  101  are provided. 
     All the other clamps  101  are essentially used to fix the supporting structure  2  and capacitor  110  mechanically to one another and each clamp grips around the supporting structure  2  and the capacitor  110  of one surface  20  of the supporting structure  2  up to the electrode  112  of the capacitor  110  assigned to the “+” pole. If any such mechanical clamp  101  is electrically conducting, it must be electrically isolated from the capacitor electrode  112  assigned to the “+” pole. 
     In  FIG. 1  additional conductor bars  330  in the form of metal strips are present, each of which additionally electrically interconnects the electrode  112  of the capacitor  110  assigned to the “+” pole and the conductor bars  3  assigned to said “+” pole, in particular via the common conductor bar  33 , and helps to further improve the electrical conductivity between the electrode  112  of the capacitor  110  and a conductor bar  3  assigned to the “+” pole. 
     The capacitor  110  is, for example, preferably implemented in such a way that each electrode  111  and  112  consists of a metal plate or foil  111 ′ or  112 ′ from which thin planar-shaped parallel metal laminations  114  project vertically in a comb-tooth-like manner, some of which can be seen in section in  FIG. 3  in an opening  116  (not present in reality) in an outer wall  115  of the capacitor  110  and are perpendicular to the drawing plane of  FIG. 3 . The two plates  111 ′,  112 ′ are brought together in such a way that, apart from one lamination, at one end of each plate each lamination of a plate is disposed between two laminations of another plate and separated from these two laminations by the dielectric  113 . 
     In the embodiments shown, current is collected by the phase conductor bars  3  designated “N”. The “−” pole is preferably at ground potential, the “+” pole e.g. at 6 V, 12 V or 42 V. 
     It must be borne in mind that all the water-rich parts leading away from the supporting structure  2  tend to oscillate during vibrations, resulting in rapid fatigue of the joints particularly at the anticipated high temperatures. Because of the required currents of several hundred amperes, the supply leads would have to be implemented with a very large cross-section in order to prevent them from overheating in the very hot environment. By means of adhesive attachment to the supporting structure  2 , the losses in the form of heat can be dissipated so that even thin metal sheets are adequate as conductor bars  3 . As the bars  3  as well as the layers  6  of isolating material are disposed directly on the supporting structure  2  and closely adjacent to one another, the oscillations against one another remain negligibly small. Short bridging links  4 ,  40 ,  41  have natural frequencies such that they are unlikely to be excited to resonance. A clamping device  100  with connections in the form of electrically conducting clamps  101  on the supporting structure with the cooler  90  additionally ensures that the thick connection cables cannot pull off the adhesively attached conductor bars  3 .