Abstract:
The invention relates to a contacting part ( 5 ) for a drive module ( 1 ), comprising: a main body for providing contacting of a brush-commutated drive motor ( 2 ) by means of brushes; at least one supply line ( 62 ), in particular a punched-grid line ( 62 ), for electrically contacting the drive motor ( 2 ); a circuit surface ( 57 ), to which a conducting track is directly applied by means of an MID technique; and at least one component ( 59 ), in particular a surface-mounted device ( 59 ), which is electrically connected to the conducting track ( 58 ).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to drive modules, in particular drive modules with electric motors. The invention furthermore relates in particular to the arrangement of EMC components and/or sensors for sensing the position of the rotor in electric machines for drive modules. 
         [0002]    Electric motors in drive modules, such as, for example, power window drive modules in motor vehicles, can be provided as brush-commutated DC motors. Electric motors of this type are provided with brush supports which hold brushes for the electric commutation of the electric motor. The brushes are customarily electrically connected to an external plug connector via a leadframe. 
         [0003]    In order to reduce EMC interfering signals on the supply lines, EMC components and/or sensors for sensing the position of a rotor are electrically connected to leadframe lines of the leadframe. The EMC components and/or sensors can be provided as wired components which are connected to the leadframe lines by a welding or soldering process. 
         [0004]    In order to save construction space, the wired components can be replaced by SMD components which are either directly connected to the leadframe lines or are placed into a suitable printed circuit board which is electrically connected to the leadframe lines. However, the electric contacting of SMD components frequently turns out to be complicated in practice. 
         [0005]    Electric machines for drive modules are generally provided with a pole pot housing and a contacting part which is placed onto the end side thereof and provides brush supports for receiving brushes via which the rotor of the electric machine can be electrically contacted. The contacting part furthermore has leadframe lines which end at a plug connector, wherein a circuit consisting of SMD components and/or one or more sensors for detecting the position of a rotor is arranged between the plug connector and the brushes. The arrangement of the components increases the construction space required and therefore influences the overall size of a drive module in which the brush support element is inserted. 
         [0006]    It is the object of the present invention to provide a contacting part for a drive module, which contacting part serves for receiving brush supports and for electric contacting thereof. Furthermore, the contacting part is intended to be provided in a space-saving manner with electric components, in particular EMC components and/or one or more sensor components. 
       SUMMARY OF THE INVENTION 
       [0007]    This object is achieved by a contacting part for a drive module and by the electric machine and the drive module according to the invention. 
         [0008]    According to a first aspect, a contacting part for a drive module is provided, comprising: 
         [0009]    an electrically non-conductive basic body for providing contacting of a brush-commutated drive motor via brushes; 
         [0010]    at least one supply line, in particular a leadframe line, for electrically contacting the drive motor; 
         [0011]    a circuit surface of the basic body, on which a strip conductor is directly applied by means of an MID technique; and 
         [0012]    at least one electric component, in particular an SMD component, which is electrically connected to the strip conductor. 
         [0013]    One concept of the above contacting part consists in providing the basic body of the contacting part with a circuit surface onto which a strip conductor is directly applied. In other words, the strip conductor is directly applied onto the non-conductive material, in particular the plastics material, of the basic body of the contacting part. It is thereby possible to dispense with both wired components and with printed circuit boards for the connection of SMD components and therefore to considerably reduce the construction space required for the provision of the components. 
         [0014]    Furthermore, it is possible to use conventional SMD components for application onto the strip conductor applied on the surface of the contacting part. 
         [0015]    Moreover, the contacting part can be provided with simplified geometry since holders for components or printed circuit boards can be omitted. The contacting part is frequently produced as an injection molded part, as a result of which the outlay for the production can be considerably reduced and, furthermore, plastics material can be saved. 
         [0016]    In addition, because of the shorter connections of EMC components, an improved EMC behavior can be achieved. 
         [0017]    Furthermore, the at least one supply line can run at least in sections in a direction of extent, wherein the circuit surface is arranged transversely with respect to the direction of extent. 
         [0018]    Alternatively, the at least one supply line can run at least in sections in a direction of extent, wherein the circuit surface is arranged parallel to the direction of extent, and wherein, for contacting the at least one supply line, the strip conductor is guided onto an adjacent supply line surface which is arranged transversely with respect to the direction of extent. 
         [0019]    According to an embodiment, it can be provided that the component is connected to the strip conductor and/or the strip conductor is connected to the at least one supply line by a conductive material, in particular a conductive adhesive or a solder material, being applied between the contact of the component and the strip conductor or between the at least one supply line and the strip conductor. 
         [0020]    It can be provided that a portion of the supply line is accessible via an opening close to one end of the strip conductor to be contacted, wherein a portion of the supply line penetrates the strip conductor to be contacted, or wherein a portion of the supply line is guided on a surface of the contacting part and the strip conductor is adjacent to the portion of the supply line. 
         [0021]    According to a further aspect, a drive module is provided which comprises a drive motor and the above contacting part which is connected to the drive motor in order to provide contacting of the drive motor via the supply lines. 
         [0022]    Furthermore, the drive module can be inserted into a housing of the drive motor. 
         [0023]    A transmission case can be arranged on a side of the contacting part that is situated opposite the drive motor, wherein the circuit surface projects into the transmission case. 
         [0024]    According to a further aspect, a method for producing a contacting part for a drive module is provided, the method comprising the following steps: 
         [0025]    providing a non-conductive basic body, in particular made from a plastics material, with at least one at least partially embedded supply line for providing contacting of a brush-commutated drive motor; 
         [0026]    applying a strip conductor directly onto a circuit surface of the basic body by means of an MID technique; and 
         [0027]    electrically contacting at least one electric component, in particular an SMD component, via the strip conductor. 
         [0028]    Furthermore, it can be provided that the electric contacting of the electric component is undertaken with the aid of a curing conductive material, in particular a conductive adhesive. 
         [0029]    It can be provided that the electric component is electrically contacted with the aid of a curing conductive material, in particular a conductive adhesive. 
         [0030]    Furthermore, the strip conductor can be applied onto the circuit surface by means of one of the following methods: 
         [0031]    printing with a film made from a conductive material using a hot embossing die which depicts the structures of the strip conductor as embossed surfaces such that that region of the film which is acted upon by the hot embossing die fuses with the material of the basic body and remains adhering to the basic body when the film is peeled off, while the remaining region of the film is detached from the circuit surface; 
         [0032]    spraying the circuit surface through a patterning mask with conductive metal particles which are formed so as to adhere such that the structure of the strip conductor is formed on the circuit surface in a manner corresponding to the patterning mask; and 
         [0033]    inscribing the circuit surface with the aid of laser direct patterning in accordance with the structure of the strip conductor such that the material of the basic body is activated in the region of the strip conductor to be applied, wherein the strip conductor is produced by electrodeposition metallization of the activated region. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    Preferred embodiments of the present invention are explained in more detail below with reference to the attached drawings, in which: 
           [0035]      FIG. 1  shows an illustration of a drive module with a drive motor and a transmission case, which are connected to each other via a contacting part; 
           [0036]      FIG. 2  shows an illustration of a contacting part with applied components; 
           [0037]      FIG. 3  shows an illustration of the contacting part from a further viewing direction to illustrate the assembly direction for the components; 
           [0038]      FIG. 4  shows a more detailed illustration of the circuit surface and the contacting of the leadframe lines; 
           [0039]      FIG. 5  shows an illustration of a further contacting part with applied components; 
           [0040]      FIGS. 6   a  and  6   b  show a perspective and sectional illustration of a manner of contacting between a leadframe line and a strip conductor on the circuit surface; 
           [0041]      FIGS. 7   a  and  7   b  show a perspective and sectional illustration of a further manner of contacting between a leadframe line and a strip conductor on the circuit surface; and 
           [0042]      FIGS. 8   a  and  8   b  show a perspective and sectional illustration of a further manner of contacting between a leadframe line and a strip conductor on the circuit surface. 
       
    
    
     DETAILED DESCRIPTION 
       [0043]      FIG. 1  shows a perspective illustration of a drive module  1  in the form of a power window module for use in motor vehicles with electric power windows. The drive module  1  has a drive motor  2  which is arranged on a transmission case  3 . An output shaft  4  for driving a mechanism, for example for raising or lowering a window in an electric power window system of a motor vehicle, projects out of the transmission case  3 . A contacting part  5  is arranged between the transmission case  3  and the drive motor  2 , the contacting part mechanically connecting the drive motor  2  and the transmission case  3  to each other. 
         [0044]    The drive motor  2  is accommodated in a stator  21  which, at a first end  22 , provides a bearing receptacle  23  for the mounting of a motor shaft (not illustrated). The contacting part  5  is arranged at an end  24  of the stator  21  which is situated opposite the first end  22 . 
         [0045]    The drive motor  2  is designed in such a manner that a commutator arranged on the motor shaft projects into the contacting part  5  and is contacted there by brushes (not shown) held in a brush support. The motor shaft penetrates the contacting part  5  and projects into the transmission case  3  where said motor shaft can be connected, for example, to a worm gear in order to engage in a corresponding transmission arranged in the transmission case  3 . 
         [0046]    The contacting part  5  is illustrated separately in  FIG. 2 . The contacting part  5  has a basic body which is preferably manufactured as a single piece from a plastics material as an injection molded component. 
         [0047]    The basic body has a drive module portion  51  and a connector portion  52  which are connected to each other via a connection portion  53 . The contacting part  5  is preferably produced as a single piece from an electrically non-conductive material, for example a plastics material, for example in an injection molding process, and serves to ensure contacting of the brushes in the drive module portion  51  via the connector of the connector portion  52 . 
         [0048]    The connector of the connector portion  52  contains protruding contact pins which can be contacted via a suitable plug connector. The contact pins are formed by the ends of leadframe lines  62  of a leadframe, which leadframe lines are in particular embedded in the material of the contacting part  5  in the connection portion  53 . The leadframe lines  62  of the leadframe serve as supply lines for the drive motor  2 . 
         [0049]    The drive module portion  51  has a first holding portion  54  with holding structures which are inserted into the second end  24  of the stator  21  such that the contacting part  5  sits fixedly on the stator  21  of the drive motor  2 . The contacting part  5  and the stator  21  can be connected to each other by connection elements  26 , such as, for example, screws. In the first holding portion  54  of the contacting part  5 , the brushes are arranged in corresponding brush supports in order electrically to contact the commutator located on the rotor shaft of the drive motor  2 . 
         [0050]    The first holding portion  54  is adjoined by a brush support base  55  of the basic body of the contacting part  5 . On that side of the brush support base  55  which is situated opposite the first holding portion  54 , a second holding portion  56  with corresponding holding structures is provided, the holding structures, in the fitted state, projecting into the transmission case  3  and thereby connecting the contacting part  5  to the transmission case  3 . 
         [0051]    The second holding portion  56  of the basic body has a circuit surface  57  which can be oriented in particular parallel to the axis of the motor shaft and in the direction of the connection portion  53 . Alternatively, the circuit surface  57  can also be provided on other surfaces, such as, for example, on the first holding portion or on the brush support base  55 . 
         [0052]    On the circuit surface  57 , a strip conductor  58  is applied directly onto the surface of the material of the basic body of the contacting part  5  with the aid of a suitable technique. The strip conductor  58  can be formed, for example, from copper, silver or another conductive material. The strip conductor  58  can be applied onto the material of the contacting part  5  with the aid of various methods. 
         [0053]    SMD components  59  are applied onto the strip conductor  58  by means of a suitable method, for example with the aid of a conductive adhesive or by soldering, and therefore the SMD components  59  are held reliably on the strip conductor  58  and electrically contact the latter. The components  59  can comprise EMC components, such as, for example, inductors or capacitors, and, furthermore, have one or more sensor components, such as, for example, a Hall sensor, which is arranged on the circuit surface  57  in such a manner that it is situated opposite a ring magnet (not shown) on the motor shaft (not shown) in a direction perpendicular to the axial direction of the motor shaft. The strip conductor  58  is provided on the circuit surface  57  in the form of an MID (Molded Interconnect Device). 
         [0054]    In a first method for the application of a strip conductor, the circuit surface  57  can be printed with a film made from an electrically conductive material, for example a copper film, specifically using a hot embossing die which reproduces the structures of the strip conductor  58  as heated embossed surfaces such that those regions of the film which are acted upon by the hot embossing die fuse with the plastics material of the circuit surface  57  and remain adhering to the plastics material when the film is peeled off, while the remaining regions of the metal film are not connected to the circuit surface  57  and are detached therefrom. 
         [0055]    In a further method, the circuit surface  57  can be sprayed via a mask with conductive metal particles which are designed so as to adhere in a suitable manner. For example, a spray of silver particles can be sprayed onto the circuit surface  57  through the patterning mask, wherein the metal particles can be connected to the material of the circuit surface  57  by means of a suitable adhesive, a temperature or sufficiently high impact energy. Alternatively or additionally, solvent or the like can also be added to the spray in order to connect the metal particles permanently to the material of the contacting part  5 . 
         [0056]    With the aid of a third method, the circuit surface  57  can be inscribed in accordance with the structures of the strip conductors by means of laser direct patterning in such a manner that the material, in particular the plastics material, of the contacting part  5  is activated in order then to be able to be metalized by electrodeposition. This process is also referred to as electrochemical plating. 
         [0057]      FIG. 3  shows a further perspective illustration of the contacting part  5 , to be precise in a direction of observation parallel to the extent of the circuit surface  57 . The assembly direction B is seen as a direction perpendicular to the circuit surface  57 . In the direction of the assembly direction B, the SMD components  59  are applied onto the strip conductor  58  and are subsequently fixed or soldered on using the conductive adhesive. 
         [0058]      FIG. 4  shows a top view of the circuit surface  57 . The circuit surface  57  is adjoined by the connection portion  53 , into which leadframe lines  62  as supply lines to the drive motor  2  are embedded. The circuit surface  57  protrudes substantially perpendicularly or transversely with respect to the direction of extent of the leadframe lines  62 . At the position at which the circuit surface  57  sits on the brush support base  55 , openings  60  are provided in the material of the contacting part  5  in order to expose the leadframe lines  62  there. The strip conductor  58  is guided to the openings  60 . The circuit formed by the SMD components  59  is now contacted by the leadframe lines  62  through the openings  60 . 
         [0059]    As illustrated in  FIG. 4 , the strip conductor  58  is provided with ends  61  facing the openings  60 . Contacting of the leadframe lines  62  by the ends  61  of the strip conductor  58  can be undertaken in a working step of the conductive adhesive bonding of the components  59  on the strip conductor  58 . For this purpose, a spot of conductive adhesive has to be introduced into the openings  60  such that the spot of adhesive extends from the leadframe lines  62  as far as the ends  61  of the strip conductor  58  and thereby produces electric contacting. The spot of adhesive is then located in the opening  60 , contacts the exposed portion of the leadframe line  62  concerned and is of a sufficient size in order likewise to enter into electric contact with the end  61  of the strip conductor  58 . 
         [0060]    By means of the provision of the SMD components  59  on the circuit surface  57 , a construction space for wired components or for a printed circuit board, such as, for example, an interference suppression board, can be saved. The low overall height of the SMD components  59  means that the provision of additional construction space for introducing the components  59  is generally not necessary, and therefore the entire drive module  1  can be constructed in a space-saving manner. In addition, improved electric properties should be anticipated since the components  59  can be connected with a shorter connection to the leadframe lines  62 . 
         [0061]    A further contacting part  50  is illustrated separately in  FIG. 5 . As in the above embodiment, the contacting part  50  has a drive module portion  51  and a connector portion  52 , which are connected to each other via a connection portion  53 . However, in contrast, rather than being arranged transversely with respect to the direction of extent of the leadframe lines  62 , the circuit surface  57  is arranged parallel thereto, wherein the strip conductor  58  extends to a supply line surface  65  which, as part of the circuit surface, runs transversely with respect to the direction of extent of the leadframe lines  62  such that contacting with the leadframe lines  62  can be undertaken in the manner described above. 
         [0062]      FIGS. 6   a - 6   b  illustrate a perspective and cross-sectional illustration through a further configuration of the connection region between one of the leadframe lines  62  and the strip conductor  58 . It is illustrated in the embodiment shown that the leadframe line  62  is led up to the strip conductor  58  and is adjacent thereto. By means of application of a conductive spot of adhesive  63 , which extends over part of the strip conductor  58  and part of the leadframe line  62 , an electric connection can be produced. 
         [0063]      FIGS. 7   a  and  7   b  illustrate a perspective and cross-sectional illustration through the connection region between one of the leadframe lines  62  and the strip conductor  58  in a further variant. In the embodiment shown, a recess  64  is provided, wherein the strip conductor  58  is located on the surface on which the recess  64  is provided. In particular, the recess  64  can penetrate the strip conductor  58 . By introduction of a drop of glue  67 , which completely fills the recess  64 , the electric connection can be produced. In order to relieve the connection with the conductive adhesive of load thermally, the leadframe line  62  can have a branching or protruding structure  66  through which thermal stresses are reduced. 
         [0064]      FIGS. 8   a  and  8   b  illustrate a perspective and cross-sectional illustration through the connection region between one of the leadframe lines  62  and the strip conductor  58  in a further variant. It is illustrated in the embodiment shown that one of the leadframe lines  62  projects out of the body of the contacting part  5  and the strip conductor  58  is arranged around the projecting portion of the leadframe line  62 . By application of the conductive adhesive onto the projecting portion of the leadframe line  62 , an electric connection between the leadframe line  62  and the strip conductor  58  can be produced.