Patent ID: 12211629

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG.1shows the cross section of a contact system3. The contact system comprises a heat sink1and a support body2with a reliable insulation in the form of an insulating layer4. The insulating layer4is located between the heat sink1and the support body2. For this, the heat sink1has a first surface10which is intended for the contacting with the support body2. The support body2has a contact area21which is intended for the contacting with the first surface10of the heat sink1.

For the sake of clarity, elements for ensuring a lasting contact between heat sink1and support body2have been omitted. This can be realized by means of for example a screw connection, a spring connection, a clamping connection, etc. These can be referred to generally as fastening devices. The support body2can take the form of for example a semiconductor module or a current bar. In the case of a contact system3comprising heat sink1and current bar, for example, it must also be ensured that there are no equalizing currents between heat sink1and support body2as a result of different electrical potentials. Heat sink1and support body2are therefore electrically insulated from each other by means of the insulating layer4. Unwanted equalizing currents between these bodies1,2are prevented thereby.

The contact system3therefore has a three-layer structure comprising the heat sink1with a first electrical potential, an insulating layer4, and a support body2which carries a second electrical potential, the first and the second electrical potentials generally differing from each other. The structure of this exemplary embodiment serves to cool a current bar via a heat sink1for example. The current bar forms the support body2in this case.

FIG.2is a detail view of the circular region shown inFIG.1on the left-hand side of the periphery of the support body2. In order to avoid repetition, reference is made to the description ofFIG.1and to the reference signs assigned there. It can be seen from the support body2in this case that it has a geometric flaw, for example a burr5, which projects from the regular geometry of the structural element. This flaw could penetrate the insulating layer4completely when the support body2is pressed or pushed onto the heat sink1, resulting in an electrical contact between heat sink1and support body2and therefore an unwanted electrical connection of the potentials that must be separated. Alternatively, it could penetrate the insulating layer4only partially, as a result of which the contact, for example due to effects of settling or partial discharge, might only occur after a time delay and might not be reliably identifiable in tests.

The effect of the flaw is particularly critical if the insulating layer4is very thin and/or soft, which applies in the case of for example limited structural space or the need for thermal penetration.

FIG.3shows an exemplary embodiment of the proposed contact system3in cross section. In order to avoid repetition, reference is made to the description ofFIG.1andFIG.2and to the reference signs assigned there. In this exemplary embodiment, recesses11have been introduced into the first surface10of the heat sink1. These counteract geometric flaws that are present, for example a burr5of the support body1.

The support body2ideally has chamfered edges as per its specification for protecting the insulating layer4against damage. In the illustration according toFIG.3, the right-hand edge of the support body2at the transition zone to the contact area21is designed as a beveled edge and the left-hand edge of the support body2at the transition zone to the contact area21as rounded edges. This does not however provide reliable protection against projecting parts of the support body2, The risk of damage is therefore reduced but not eliminated.

Therefore, in order to improve the contact system3in terms of contacting with electrical insulation, one or more recesses are provided on the first surface10of the heat sink1, These are able to accommodate projecting geometric flaws such as for example a burr5, without pressure being exerted on the intermediate insulating layer4, This offers reliable protection for the insulating layer4, because the recesses11allow the insulating layer4to withdraw into a hollow space of the recess11if burrs5or other protruding geometric flaws are placed thereon. The force effect on the insulating layer4is significantly reduced thereby and prevents the insulating layer4from being damaged or even penetrated by the support body2. The hollow space is formed by means of a material recess, designated recess11, in the heat sink1. In the case of a contact system3, this is advantageously located at the edge of the contact area21of the support body1. It can have a rectangular cross section in particular, as illustrated in the left-hand recess11. Alternatively or additionally, it is also possible for the recess11to have a rounded cross section, in particular at the transition zone to the first surface10. Furthermore, cross sections which are shaped differently are also possible and effective for the recess11.

The insulating layer4can overlap the hollow space completely as illustrated, but can also overlap the hollow space only partially.

Furthermore,FIG.4shows the cross section of a further exemplary embodiment having an oval cross section of the recess11. In order to avoid repetition in the explanation forFIG.4, reference is made to the description ofFIGS.1to3and to the reference signs assigned there. The heat sink1advantageously has a chamfered edge, in particular on that side which is overhung by support body2. This again reduces the load on the insulating layer4. Particularly in the case in which the insulating layer4actually overlaps the entire recess11, It has proven advantageous to additionally likewise embody the edge on the opposite side of the recess as a chamfered edge. The chamfered edge prevents the heat sink1from penetrating into the insulating layer.

FIG.5shows a further heat sink1with recesses11. By virtue of the perspective illustration, the unbroken tracks of the recesses11can be seen, Two separate recesses11are provided in the left-hand part of the heat sink1, allowing two support bodies2to be contacted. The support bodies2in this case have a contact area which is for example rectangular and overlaps parts of the recess11when contacted, A recess in the form of a figure-8 is shown in the right-hand part of the heat sink1. The different sections of the recess can have different widths in this case. In particular, the central path of the recess can be wider in the figure-8-shaped embodiment. This allows greater flexibility in the utilization of the heat sink. The track in the figure-8-shaped embodiment of the recess11is likewise an unbroken track. For example, two support bodies2can be contacted at this recess11. The recess is then used by both support bodies2at the central path of the recess11. It is alternatively also possible respectively to contact a large support body2which uses only the outer part of the recess11. This type of recess11is particularly flexible, since different embodiments of the support body2can be connected to the heat sink1while making full use of the cited advantages.

In summary, the invention relates to a heat sink for contacting with a support body in an electrically insulated and/or heat-conducting manner, said heat sink having a first surface. For improved contacting, it is proposed that the first surface should have at least one recess, said recess being located in a region of the first surface, which region is intended for contacting with the periphery of a contact area of the support body, said recess forming an unbroken track on the first surface, and said first surface being embodied substantially as a flat area. The invention further relates to a contact system having such a heat sink and a support body, a contact area of the support body being located on the heat sink in such a way that the recess of the heat sink extends completely along the periphery of the contact area. The invention further relates to a method for producing such a contact system, the support body being positioned on the heat sink in such a way that the entire periphery of the contact area of the support body extends along the recess of the heat sink.