Patent Document

CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a 35 USC 371 application of PCT/EP2008/065301 filed on Nov. 11, 2008. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is based on a heat sink of at least one electrical component. 
     2. Description of the Prior Art 
     It is known to mount heat sinks on electrical power components, to ensure adequate heat dissipation from the power component. Typically, such heat sinks comprise a face, which establishes large-area contact with the power component, and fins protruding transversely from that face which effectively increase the surface area of the heat sink and improve the heat dissipation. Often, the heat sink is joined to the power component by a heat-conducting paste or a potting composition. In the event of vibration or major fluctuations in acceleration, damage to the power component can occur. 
     ADVANTAGES AND SUMMARY OF THE INVENTION 
     It is proposed that a first heat sink portion is embodied as a spring, and a contact face is provided in the first heat sink portion, between the heat sink and the at least one component. 
     Advantageously, an electrical component joined to the heat sink on the first heat sink portion can be protected by the spring action of the heat sink portion, for instance in the event of vibration, impact, or fluctuations in acceleration. In the event of deformation, for instance after major fluctuations in acceleration, the spring action of the heat sink can halt the electrical component and return it to the original position. Advantageously, the first heat sink portion can be joined to a second heat sink portion in such a way that this first heat sink portion is deflectable, for instance resiliently, relative to the second heat sink portion. Thus the first heat sink portion can be angled relative to the second heat sink portion or joined to it by a spring element. If the second heat sink portion is rigidly fixed, then impacts or vibration can be absorbed by the first heat sink portion. A plurality of components to be cooled can be disposed on the heat sink, and at least one of the components is attached mechanically as described, and as a result is attached thermically. 
     The first heat sink portion, in a preferred feature, can be angled transversely to a second heat sink portion, and in the mounted state the second heat sink portion is intended for being secured to a circuit board. The first heat sink portion can be moved flexibly counter to the second heat sink portion. Vibration can easily be cushioned by spring action. 
     In a preferred refinement, the second heat sink portion can be secured in the mounted state to a circuit board by at least one securing element. Preferably, the circuit board can be firmly clamped. Thus a screw connection, for instance, which requires additional securing elements and is time-consuming to produce, can be advantageously avoided. The at least one securing element can preferably be embodied as a detent or as a crimped foot and can engage corresponding recesses in the circuit board. As a result, a mechanical hold of the heat sink on the circuit board can be attained without additional securing elements. Solid cohesion of the circuit board and heat sink can be attained with and without additional potting composition. However, the securing can also be done in such a way that the circuit board can be slid in on the heat sink portion. Fixation against shifting can be ensured, for instance by means of a potting composition that is disposed for instance above the connection point of the circuit board and the heat sink portion. 
     In an advantageous feature, the first heat sink portion can be embodied in hooplike form, with a first leg and a second leg. As a result of the hooplike embodiment, an advantageous spring action of the heat sink can be reinforced. As a result of this embodiment, a secure, reliable two-dimensional contact of the heat sink with the at least one component, and thus both a secure fixation of the at least one component and reliable heat dissipation can be ensured. A reliable connection with the at least one component can be made, and an advantageous compact, narrow structural shape of the heat sink can be achieved. 
     Advantageously, the first heat sink portion can be firmly clampable to the at least one component. Favorably, the first heat sink portion, for instance, can be provided for contact with a main face of the at least one component. Laterally on the heat sink portion, two guide elements may be embodied, which for instance firmly hold opposed side faces of the component and serve for instance to guide the at least one component. 
     In an expedient feature, the contact face can be disposed on an inner side of at least one of the legs. Then the at least one component can be disposed in a hollow space between the legs. Advantageously, the at least one component can be clampable between the first and the second leg. The heat transfer can be ensured by the clamping force of the two legs, and the at least one component can be securely fixed. It is also conceivable for further electrical components to be secured, for instance screwed, to one or both legs. For instance, the component disposed between the legs may be a capacitor, while other components, such as field effect transistors, can be disposed on the outer side of one or both legs. 
     In an alternative feature, the contact face can be disposed on an outer side of one of the legs. The heat transfer can be ensured by a contact pressure between the at least one component and the heat sink. Advantageously, in the mounted state, the at least one component can be clampable between the contact face on the outer side of one of the legs and a further clamping portion in the heat sink. Favorably, the clamping portion can be stamped out from the heat sink and suitably bent in a curve. Here as well, further electrical components may be disposed on the first heat sink portion, on its outer side, for instance being screwed to an outer side. 
     Overall, the heat sink can be inexpensively made as a stamped part, in which the first heat sink portion, the guide elements, the clamping element, and securing elements can be angled in a suitable way. The mounting of the heat sink or of the component can be done quickly and economically. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages will become apparent from the ensuing description of the drawings. In the drawings, exemplary embodiments of the invention are shown. The drawings, description and claims include numerous characteristics in combination. One skilled in the art will expediently consider the characteristics individually as well and put them together to make useful further combinations. 
       The drawings schematically show the following: 
         FIGS. 1   a, b , a preferred embodiment of a heat sink, with an electrical component that is firmly clamped in a heat sink portion, in perspective ( FIG. 1   a ) and in side view ( FIG. 1   b ); and 
         FIGS. 2   a, b , a preferred embodiment of a heat sink, with an electrical component that is pressed against a heat sink portion, in perspective ( FIG. 2   a ) and in side view ( FIG. 2   b ). 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the drawings, elements that are identical or have the same function are identified by the same reference numerals. 
     In  FIGS. 1   a  and  1   b , a first preferred feature of a heat sink  10  can be seen in perspective ( FIG. 1   a ) and in side view ( FIG. 1   b ). An electrical component  42  mounted on a circuit board  40  is connected to the heat sink  10  for heat dissipation. In the exemplary embodiment shown, a first heat sink portion  12  is embodied as a spring, in that the first heat sink portion  12  is bent at an angle transversely, in particular vertically, from a second heat sink portion  14 . The second heat sink portion  14  is embodied in platelike form and is affixed to the circuit board  40  with securing elements  16 . 
     Advantageously, the second heat sink portion  14  can be secured to the circuit board  40  by means of a positive-engagement connection, for instance in this case with so-called crimped feet as securing elements  16 , which engage corresponding recesses, not identified by reference numeral, in the circuit board  40 . The circuit board  40  can be connected for instance to a further circuit, not shown, or may be a portion of a larger circuit board. 
     Electrical contacts of the component  42  with the circuit board  40  are extended through suitable openings  36  in the second heat sink portion  14 . For heat dissipation, the component  42  is mechanically connected to the first heat sink portion  12 . The component  42  is spaced apart somewhat from the main face of the second heat sink portion  14  and is seated on a hump  32  of the second heat sink portion  14 . 
     The first heat sink portion  12  is embodied in hooplike form and has a first leg  18  and a second leg  22 , parallel to the first, which are connected by a connecting piece  26 . A contact face  20  between the heat sink  10  and the component  42  that acts in a targeted way as a heat diversion face, is provided in the first heat sink portion  12 . 
     The first heat sink portion  12  includes main faces, not identified by reference numeral, of the component  42 , and these faces are contacted over a large area by the legs  18 ,  22 , in that with a clamping force, the two legs  18 ,  22  contact the component  42  disposed in the hollow space  28  between the legs  18 ,  22 . Accordingly, the contact face  20  is disposed on an inner side of the first leg  18 . There, the leg  18  rests over a large area on the component  42 . The second leg  22  rests with its rounded end piece  24  on the opposite side and presses the component against the first leg  18 . 
     The component  42  can be guided and optionally even held by means of guide elements  30 , which are disposed on the heat sink portion  12  and protrude transversely from it. The guide elements  30  are disposed laterally on the first leg  18 , engage side faces of the component  42 , and serve to guide the component  42 . 
     The component  42  may for instance be a capacitor. In a variant, not shown, further components, such as field effect transistors, can be disposed on, in particular screwed to, the outer side of the leg  18  and/or  22  of the first heat sink portion  12 . 
     The foregoing relates to the preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. 
       FIGS. 2   a  and  2   b  show an alternative embodiment in perspective ( FIG. 2   a ) and in a side view ( FIG. 2   b ), in which a contact face  20  intended for targeted heat dissipation is disposed on an outer side of one leg  22  of a heat sink  10 . 
     An electrical component  42  mounted on a circuit board  40  is connected for heat dissipation to the heat sink  10 . A first heat sink portion  12  is embodied as a spring, in that the first heat sink portion  12  is bent at an angle transversely, in particular vertically, from a second heat sink portion  14 . The second heat sink portion  14  is embodied in platelike form and is affixed to the circuit board  40  with securing elements  16 . 
     Advantageously, the second heat sink portion  14  can be secured to the circuit board  40  by means of a positive-engagement connection, for instance in this case with so-called crimped feet as securing elements  16 , which engage corresponding recesses, not identified by reference numeral, in the circuit board  40 . The circuit board  40  can be connected for instance to a further circuit, not shown, or may be a portion of a larger circuit board. 
     In the exemplary embodiment shown, in the mounted state, the component  42  can be clamped between the contact face  20  on the outer side of one of the legs  18 ,  22  and a further clamping portion  34 . The clamping portion  34  can be stamped out of the second heat sink portion  14  and curved accordingly. 
     The first heat sink portion  12  is designed such that the two legs  18 ,  22  are pressed against one another, while the legs  18 ,  22  seek to move apart from one another. As a result, a spring force is exerted against the component  42 , which the clamping portion  34  counteracts and thus presses the component  42  firmly against the outer side of the second leg  22 . As a result of the intimate two-dimensional contact, a good heat transfer from the component  42  to the leg  22  and thus into the heat sink portion  12  can be accomplished. 
     Here as well, the component  42  is held or guided on the first heat sink portion  12  by means of guide elements  30 . The guide elements  30  are disposed laterally on the first leg  18 , are angled transversely to it, and engage side faces of the component  42 . 
     The component  42  may for instance be a capacitor. In a variant, not shown, further components, such as field effect transistors, can be disposed on, in particular screwed to, the outer side of the leg  18  and/or  22  of the first heat sink portion  12 . 
     The foregoing relates to the preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.

Technology Category: 5