Control unit with sealed canal for cooling fluid

p0001The present invention relates to an electronic unit, in particular control device for a motor vehicle, with electrical and / or electronic components which are arranged on an upper surface of a thermally conductive electronic base plate and thermally coupled to this base plate, wherein the bottom plate is in turn thermally coupled with a coolant passage.

p0002Such electronic units are known in many versions in particular in the field of power electronics and have the advantage of being created during operation of the electrical or electronic components heat (power loss) to a coolant passage through coolant flowing (z. B. cooling liquid such as water) can be issued ,

p0003However, the problem here is more or less great risk of leakage of the coolant passage, which is accompanied by such a cooling method. Depending on the type of refrigerant used and the thus-cooled circuitry, this problem particularly in a compact design of the electronics unit then be particularly serious if escaping coolant can reach the circuit or its components due to a leak. An example of this is the water cooling of power electronics, in which the operation consists of relatively high electrical voltages. In this case, the penetration of cooling water to the electronics or the ingress of cooling water into an electronics housing could cause a short circuit, destroying devices, or even cause a fire. A leak of the coolant passage is to be expected in practice, especially when the difference between refrigerant pressure and ambient pressure is particularly great. The risk of penetration of coolant to the electronics is especially large when both the refrigerant passage and the space occupied by the electrical or electronic components room ( "electronics space") are housed within a more or less closed housing structure.

p0004One known way to minimize the above-mentioned risks, the use of a possible reliable tight welded or brazed radiator, on which a thermal grease or a thermal adhesive electronic modules or unpopulated flat sides of circuit boards attached (z. B. screwed) are. The use of solder instead of thermal paste or thermal glue is usually not practical because the electronic modules or electronic circuit board to be frequently dismantled. Furthermore, with use of solder, the risk of cracking in the solder, so that if the thermally coupled components have different thermal expansion coefficients. Apart from these drawbacks, the use of a possible reliably sealed cooler a high production cost.

p0005It is an object of the present invention, in an electronic unit of the type mentioned to improve the sealing of the coolant passage and to reduce the risks in the event of a leak arising.

p0006This object is achieved according to the invention by a special design and arrangement of those components, which define the coolant passage. A particular advantage of the invention is that the underside of the bottom plate can enter directly into contact with the refrigerant, so a "direct cooling" can be realized.

p0007According to a first aspect of the invention it is provided that the base plate has an integrally formed on its underside with the base plate, projecting downwards and closed in a ring extending web which limits its inside together with the underside of the bottom plate and a top of a radiator portion of the refrigerant passage, wherein the top of the radiator portion is connected via a closed ring extending at the lower end of the ridge seal coolant sealed to the web.

p0008This solution is reliably prevented by the integral formation of a closed ring extending web that leaking coolant flows from the coolant passage directly to the bottom of the electronics base plate. This is especially important if this baseplate has apertures such. As screw holes, etc. and / or the coolant passage in the vicinity of an edge of the base plate is arranged so that coolant from the underside of the bottom panel rather short way (to the bottom plate periphery thereof) can reach the top of the bottom plate and thus in the electronics compartment.

p0009According to a second aspect of the invention, the above object is achieved by a radiator portion having a recess and an integrally with the radiator part formed annularly on the edge of the recess closed running web, limits its inside together with the underside of the bottom plate, the coolant passage, the underside of the bottom plate is connected to a running at the dock seal assembly coolant sealed to the web, which includes two each closed ring at the upper end of the ridge extending seals between which a closed ring extending space is limited, which is connected to a leading out of the cooler part leakage passage ,

p0010In this solution, the sealing of the coolant passage through a seal assembly at the bottom of the electronics bottom plate takes place. If a leak occurs in this area, it is still reliably prevented by a special design of the seal assembly that from the coolant passage escaping coolant directly to the underside of the base plate (and possibly from there in the electronics compartment) arrives. The seal assembly is in fact (at least two closed ring extending seals) formed "multi-stage", a closed ring extending "gap" between the seals is connected to a pressure-relieving in Undichtigkeitsfall leakage passage. So if befindliches in the coolant passage coolant should overcome the first seal, so that on the leakage passage in a controlled manner (eg. as of the electronics base plate away) can be discharged. Depending on the leak rate and flow resistance of the leakage passage is present at the second seal nurmehr a more or less considerably reduced coolant pressure.

p0011In a third aspect of the invention, the above object is achieved in that the upper surface of the base plate and components is sealed by a housing structure against the penetration of coolant and the underside of the bottom plate is connected via a closed ring extending seal coolant sealed with a closed ring extending web which is formed to protrude on an upper side of a radiator part limited upward and the inside of which together with the underside of the bottom plate, and an upper surface of the radiator portion of the refrigerant passage.

p0012In this solution, the sealing of the coolant passage through a seal at the underside of the bottom plate is carried out electronics. If a leak occurs in this area, it is still reliably prevented by the also provided sealing the top of the floor plate including devices that directly passes from the coolant passage coolant emerging in the electronics compartment. In this context it is noteworthy that the refrigerant pressure of leaking refrigerant is not present in this solution at the seal on top of the base plate. With this solution, the cooler part is screwed to the base plate, so screw holes should be provided which does not pass completely through the bottom plate, but z. B. are formed as blind holes on the underside of the bottom plate.

p0013For all above-mentioned aspects of the invention will be appreciated that the coolant passage advantageously has at least one inlet and at least one outlet for admitting coolant or for discharging coolant, ie may have to flow through the coolant passage. For all aspects may extend through such inlet or outlet through the bottom plate, by the web or by the cooler part.

p0014Further, for each of the aspects of the invention also a plurality of coolant passages may be provided, which may be either completely separately from each other (eg. As with its own inlets and outlets) or in any way "chained" (z. B. in parallel and / or series configuration) , Thus, an outlet of a coolant passage z. B. simultaneously form the inlet of a subsequent refrigerant passage.

p0015If the electronic unit has a plurality of refrigerant passages, so may be sealed according to another aspect of the invention readily a part thereof according to an aspect of the invention, and another part thereof. In other words, aspects of the invention can also be combined in one and the same electronic unit to each other.

p0016The electronic unit according to the invention is particularly suitable for use in an elevated ambient temperature, such as those present in the engine compartment of a motor vehicle.

p0017In particular, a so-called power electronics realized electronic units can be cooled reliably and relatively safe according to the invention. Here such electronic units are of particular interest in which operatively at least one point, an electrical voltage greater than 100 V occurs and the refrigerant used as such represents a short circuit and / or flammable. A preferred application is for control units of a motor vehicle, such as engine control units, gear control units, etc., especially if they are located in the engine. For such devices, there is in practice a great need for cooling of microelectronic components, in particular so-called power semiconductor components. Electric voltages greater than 100 V occur, for example in control devices for hybrid vehicles and in control devices for the control of piezo-actuated fuel injectors.

p0018In a preferred embodiment it is provided that the base plate is designed as a housing part of an electronic module containing a part of the electrical or electronic components. Electronic modules per se are known and particularly advantageous for disassembly or interchangeability. However, the use of a module housing part as a base plate for the purposes of the present invention also has the considerable advantage that the respective housing part, for example, a flat side of a total of approximately cuboid electronic module, directly adjacent to the coolant passage, or directly contacts the coolant in contact during operation. If the seal is provided in this case according to the first aspect of the invention, the housing part in question must already have the integral thereof projecting web. However, if the sealing is to take place according to the second aspect of the invention, as particularly advantageous often a conventional module (z. B. having a planar lower flat side) can be used.

p0019In a preferred embodiment it is provided that the base plate is formed as a metal plate which is attached flat against the underside of a circuit carrier for the electrical or electronic components.

p0020For the formation of the circuit substrate or the substrate may be resorted to common in the field of power electronics technologies. More generally, a layer structure of one or more interconnect layers that are structured at least partially to the formation of interconnects is (and possibly "by contact"), and one or more insulating layers (dielectric substrate) at least between adjacent wiring layers. In one embodiment, a circuit board having a ceramic substrate material and one or more wiring layers of metallic material. Advantageously, z. B. a comparatively small difference of the thermal expansion coefficients of the substrate (eg. As a ceramic material), and the common power electronics silicon material (z. B. unhoused applied silicon chips) can be realized. Obviously, however, may be provided in the context of the invention, any other circuit carrier.

p0021The above-mentioned connection of a metal plate on the underside of the circuit carrier can already during circuit board production (eg. As in a so-called DCB substrate), or subsequently, eg. As a thermal grease, a thermally conductive adhesive or soldering done. In particular, with regard to an adaptation of the thermal expansion coefficient on the one hand a circuit carrier substrate, and the other part of the metal plate used as a base plate is provided, in one embodiment, that the base plate is formed of a metal alloy, for example, AlSiC, CuW or CuMo. If the bottom plate (or a part of several base plates) from such rather "exotic" and thus made expensive materials, so in most cases a sealing of the cooling passage according to the second aspect of the invention is more advantageous since the bottom plate in shape less complex (without the bridge) can be formed. In this context it must be remembered also that in an embodiment according to the second aspect of the invention advantageously z. B. a radiator portion having a plurality of each closed ring extending and integral webs can simultaneously serve as a cooler part for more each relatively simple design and small-sized floorboards.

p0022The coolant is preferably a cooling liquid. When used in the electronics of a motor vehicle, the coolant passage can be supplied, for example, with the already existing cooling water of the cooling circuit for an internal combustion engine. Alternatively or additionally, the connection of the electronic unit or the extent provided coolant passage to a specially provided for the coolant circuit is possible. A particularly interesting application for the invention is present if the coolant passage for receiving a cooling agent having a pressure of at least 2 bar, in particular at least 3 bar is designed.

p0023In an advantageous for each seal in terms of ease of installation and sealing embodiment is provided that the web has a groove for the seal or grooves for the seals and / or connected via the seal or seal assembly with the web component, cooler part or base plate having a receiving groove for the seal or grooves for the seals.

p0024In one embodiment it is provided that a plurality of separately formed floor panels are provided, which are connected via a corresponding number of seals or sealing arrangements with a common radiator portion. Some extent is reversed may also be provided that a plurality of separately formed radiator parts are provided, which are connected via a corresponding number of seals or sealing arrangements with a common base part.

p0025In one development of the invention, the coolant passage is formed with a kühloberflächenvergrößernden structure. The structure may, for. Example, be formed from the material of the base plate or the cooling part or as a separately arranged structure (eg. As sheet metal). By suitable mounting or assembly of such structures or cooling plates (such as so-called "turbulators") may advantageously also specifically directed or turbulent and not laminar flow in the cooling passages or be accomplished to improve the cooling effect.

p0026As for the material of the sealing element used in the invention (s), so can this be advantageous to resort to materials as in the fluid seal are common (eg. As elastomers).

p0027In one embodiment it is provided that the seal or at least one is formed of a plurality of gaskets as sealing ring. Such a sealing ring can over its length considered z. B. having substantially uniform cross-section, in particular, for. Example, circular cross-section, may be formed. Alternatively or additionally, z. B. can gaskets (z. B. having a substantially rectangular cross-section) may be used.

p0028According to a preferred embodiment it is provided that the base part with the radiator part is detachably connected, in particular, for. Example, is screwed. In view of a good seal between the bottom plate and cooler part of a screw is preferably carried out by a plurality of bolts or screws, so that in a simple manner a uniform contact pressure can be achieved over the course of the seal (s). For this purpose it is particularly advantageous if a plurality of screw connection points approximately along the garter course of a seal over the seal considered essentially equidistant, is provided. When sealing the coolant passage according to the first aspect of the invention such a screw connection points can be easily provided directly in the region of a seal, ie with screws or bolts which through local recesses (passages) pass the seal. However, if the sealing is performed according to the second aspect of the invention, it is expediently to ensure that constitute such screw connection points in Undichtigkeitsfall for leaked coolant no short path from the underside of the bottom plate to the top of the bottom plate (or other areas of the electronics compartment).

p0029The invention is further described below by means of embodiments with reference to the accompanying drawings. It represents:<dl id="dl0001"><dt>Fig. 1</dt><dd>is a schematic side view of an electronic unit according to a first embodiment,</dd><dt>FIG. 2</dt><dd>a perspective view of an electronic base plate for an electronic unit according to another embodiment,</dd><dt>Fig. 3</dt><dd>is a schematic side view of an electronic unit according to another embodiment, </dd><dt>Fig. 4</dt><dd>a schematic plan view of a plate-shaped radiator part for an electronic unit according to another embodiment,</dd><dt>Fig. 5</dt><dd>a schematic of the radiator portion of Fig. 4 viewed from the opposite side,</dd><dt>Fig. 6</dt><dd>a partially sectional view of the electronic unit formed by using the bottom part of FIG. 4 and 5,</dd><dt>Fig. 7</dt><dd>a perspective view of a radiator portion of an electronic unit according to another embodiment,</dd><dt>Fig. 8</dt><dd>a perspective view of a radiator portion of an electronic unit according to another embodiment,</dd><dt>Fig. 9</dt><dd>a perspective view of the radiator portion of Fig. 8, of the opposite side viewed, and</dd><dt>Fig. 10</dt><dd>is a schematic side view of an electronic unit according to another embodiment.</dd></dl>

p0030Fig. 1 illustrates a first embodiment of an electronics unit 10 (here: engine control unit) in which are electrical and electronic components 12-1 to 12-5 disposed at an upper side 14 of a heat-conductive electronics bottom plate 16.

p0031The bottom plate 16 is made of a highly heat-conductive metallic material (eg., Aluminum or AlSiC) and connected with its top via a thermal grease on the bottom of a (not shown) circuit carrier, which the elements contributes in a conventional manner 12 and wired together. Alternatively, the base plate 16 could also be part (lower flat side) to be of such a circuit carrier.

p0032In the illustrated embodiment, a lower surface 18 of the bottom plate 16 includes a first portion 18-1 and a second portion 18-2. The first area 18-1 upwardly bounded a coolant passage 20, which flows through the operation of the electronic unit of cooling water. In the illustrated embodiment, this space 20 is further bounded laterally by the inside 22 of a closed ring extending ridge 24 and the bottom by the top 26 of a plate-shaped radiator part 28th

p0033The thermally coupled with the components 12 bottom plate 16 is thus in turn coupled by the immediate adjacency of the coolant passage 20 at the underside 18 of the bottom plate 16 thermally directly connected to the coolant passage 20 so that during operation of the electronic unit 10, an efficient cooling path of the components 12 to the cooling water given is.

p0034The top 26 of the radiator portion 28 is connected via a closed ring at the free or lower end of the ridge 24 extending seal 30 coolant sealing the web 24th The web 24 is integrally formed with the bottom plate 16 and is on its underside 18 in the downward direction from.

p0035In FIG. 1 by dashed lines is finally yet a further casing structure 32 consisting of one or several housing parts which covers protecting the electronics at the top. As shown in FIG. 1 can be seen the bottom plate 16 and / or the cooler portion 28 may also constitute part of the total system structure of the enveloping housing.

p0036In the following description of other embodiments the same reference numbers are used for functionally identical components, each supplemented by a small letter to differentiate the embodiment. Attention is paid essentially only the differences to the or the embodiments already described and expressly refer also to the description of previous exemplary embodiments. The reference numerals of in one embodiment repeatedly provided, in effect, however, analog components are numbered (each followed by a hyphen and a sequential number). In some of such components or to the totality of such components is referred to hereinafter by the nichtergänzte numeral.

p0037Fig. 2 shows a bottom plate 16a for an electronic unit according to another embodiment. In this figure, the garter-type course of a web 24a can be clearly seen, which is formed on the bottom 18a of the bottom plate 16a integral with the base plate 16a and protrudes downward.

p0038In contrast to the above-described embodiment 2, a cooling water inlet 34a and a cooling water outlet 36a in Fig. Can also be seen, which are formed (for attaching tubing) in the illustrated embodiment as a tubular connection piece and provide an entrance passage and exit passage through the web 24a passes ,

p0039Also in contrast to the embodiment described above has the web 24a within its garter course another web sections, which have a elongated contiguous, multiply bent course in the illustrated embodiment. In the example shown, this additional land portion is integrally connected to the inner side 22a of the bar 24a. It causes in addition to a mechanical stabilization of the bottom plate 16a and the (not shown) cooler part also advantageous steering of the cooling water flow, starting from the cooling water inlet 34a for cooling water outlet 36a.

p0040In contrast to the embodiment described above, the manner of connection of the (not shown) condenser portion with the illustrated base plate 16a can be seen in Fig. 2. At screw connection points 38a of the ridge 24a is respectively widened in its cross-section and forms blind holes made for a fitting of the radiator portion to the bottom plate 16a, which (not shown) screw correspondingly arranged recesses of interposed seal prevail.

p0041For the two embodiments of FIGS. 1 and 2, respectively essential that in case of leakage of the coolant passage 20 or 20a in the area of ​​the sealing ring, the cooling water can not directly in the region of the bottom 18 and 18a of the bottom plate 16 or 16 exit, but at a distance therefrom. This prevents leaking cooling water gets rather short way into the electronics compartment.

p0042Fig. 3 illustrates another embodiment of an electronic unit 10b, which is formed using an electronic base plate 16b and a radiator arranged underneath part 28b.

p0043The bottom 18b of the bottom plate 16b adjacent back directly to a coolant passage 20b which is bounded at the bottom by an upwardly facing surface 26b of the cooler portion 28b. As with the embodiments described above, the coolant passage 20b side again bounded by the inner side 22b of a closed ring around the coolant passage 20b extending ridge 24b.

p0044However, in contrast to the above-described embodiments of this web is not integral with the bottom plate, but formed integrally with the radiator part 28b. In the illustrated embodiment, the web 24b projects from the upper surface 26b upward.

p0045The bottom 18b of the bottom plate 16b 24b extending sealing arrangement coolant sealed to a at the free (upper) end of the web with web 24b. The seal assembly case consists of two each closed ring at the upper end of the web 24b extending seals 30b-1 and 30b-2, between which a closed ring extending space is limited 40b, passing with one (or more) down through the web 24b connected from the cooler portion 28b leading out leakage passage 42b.

p0046In this embodiment, it is essential that in the event of a leak of the coolant passage 20b in the region of the first sealing ring 30b-1 in the gap 40b vordringendes cooling water is discharged in a controlled manner through the leakage passage 42b to reduce the risk of intrusion into the electronics compartment. By providing the leakage passage 42b is reliably prevented in Undichtigkeitsfall bears a significant water pressure on the inside of the second seal ring 30b-2. In the example shown, the leakage passage 42b leads downward out of the radiator portion 26b.

p0047At the bottom in Fig. 3 the mouth of the leakage passage 42b, a pressure equalization element to avoid excessive positive pressure or negative pressure in the space 40b is preferably (3 not shown in Fig.) Is provided, which in practice also, for. Example, penetration of water (e.g. . B. rainwater) from the outside into the space 40b into prevented.

p0048The described use of a "double seal" between the cooling water circuit and the electronics compartment and the leakage possibility between the two orbiting individual seals to the environment, the risk of leakage and the extent of their impact is greatly reduced. The addition of a circumferential "secondary" seal 30b-2 outside the first, "primary" seal 30b-1 and the introduction of a leak between the two seals 30b-1 and 30b-2 of the optionally relatively high cooling water pressure (z. B. about 3 bar, or even more not be available at the secondary seal) to the housing. Thus the interior of the electronics is significantly less impacted because these electronics compartment is secured twice and because the place designated for the coolant passage 20b cooling water pressure may not be available at the secondary housing seal 30b-2. In the embodiment shown in Fig. 3, a part of the components 12b, namely the elements 12b-4 and 12b-5, no. 14b on the upper side of the bottom plate 16b, but adjacent to it, arranged on the top part 26b of the radiator 28b The electronics compartment is therefore partially partially delimited by the upper side 14b of the bottom plate 16b and 26b from the top of the radiator portion 28b. As seen from Fig. 3, this is due to the described "double seal" 30b-1, 30b-2, however, without problems.

p0049Deviating from the illustrated embodiment, also several floor panels could be placed side by side on top of the cooler portion 28b.

p0050Figs. 4, 5 and 6 illustrate another embodiment of an electronic unit 10c using an electronic base plate 16c and a condenser portion 28c, which is connected via an interposed, two-stage sealing arrangement 30c-1, 30c-2.

p0051Fig. 4 schematically shows the approximately rectangular contour of the approximately plate-shaped radiator part 28c when viewed from above. To the radiator part 28c an annularly closed web extending portion 24c is again provided integrally, which forms a lateral boundary for a coolant passage 20c-1.

p0052In this embodiment, further comprising a second coolant passage portion 20c-2 is provided to which will not be discussed in detail for simplicity of explanation in the following. This is mainly therefore superfluous, as the seal of this second refrigerant passage 20c-2 is formed according to the sealing of the first refrigerant passage 20c-1 described below.

p0053At the upper end of the bar 24c, a primary sealing ring 30c-1 and a secondary sealing ring 30c-2 are arranged which are symbolized in Fig. 4 by dotted lines, and, in the finished electronic unit, the sealing of the radiator portion 28c again to an electronics base plate 16c ( realize see. Fig. 6).

p0054Fig. 5, a view of the cooler portion 28c from below, illustrating further details of this embodiment. How to Spot a first larger recess 44c and a second smaller recess 46c at the bottom of the cooler illustrated portion 28c. The approximately plate shaped radiator part 28c is formed relatively thick in this embodiment. The two recesses 44c and 46c have a considerable depth, however, pass through the cooler part 28c is not complete.

p0055a further, third coolant passage 44c with the recess realized on the will not be discussed in more detail below. In contrast, the recess 46c serves to establish a connection passage between said coolant passages 20c-1 and 20c-2, the position of FIG. 4 can be seen. To this end, the recess extends 46c to a depth in the material of the cooler portion 28c into which extends into the region of the annularly extending webs (z. B. 24c) ranges. On the finished electronic unit 10c are the 5 visible in FIG. Recesses 44c, 46c covered in any suitable manner coolant sealing.

p0056Fig. 6 illustrates 10c marked in Fig. 4 with VI region of the finished electronic unit in a partially sectioned perspective view. Good to see here is the sealing of the coolant passage 20c-1 with respect to the over half (and side) of the bottom plate 16c located electronics compartment. The cooler part 28c has for this purpose the web 24c on which the coolant passage 20c-1 is limited laterally, wherein the upper end of the fin 24c the "double seal" 30c-1, 30c-2, the seal to the bottom 18c of the bottom plate 16c toward implemented.

p0057From Fig. 6 is further visible a screw 38c by a plurality of screws, by means of which the bottom plate 16c are bolted to the cooler part 28c.

p0058If fails during operation of the electronics unit 10c of the first seal ring 30c-1, so the penetration of leaking refrigerant in the electronic space is reliably prevented by the fact that the coolant is discharged via a leakage passage 42c, which simultaneously advantageously to a pressure relief a gap 40c between the two sealing rings 30c-1 and 30c-2 leads.

p0059Fig. 7 shows a perspective, bottom view of a radiator part 28d according to a similar embodiment.

p0060A special feature of this embodiment is that the cooler part 28d is formed substantially without undercuts and thus particularly inexpensive. The cooler part 28d of a large recess 44d and recesses in the region of the subsequent refrigerant passages 20d-1 and 20d-2 completely through.

p0061The refrigerant passages 20d-1 and 20d-2 are again 46d connected on the opposite side by a smaller recess with each other and otherwise laterally in each case by an annularly closed circumferential rib 24d-1 and 24d-2 restricted. These webs or opening edge portions are formed integrally with the material of the radiator portion 28d and protrude from the body of the cooler portion 28d upward (in FIG. 7 in the downward direction) from. To the closed ring extending free ends of the ribs 24d-1, 24d-2, the sealing of the refrigerant passages 20d-1 and 20d-2 is again carried out by a "double seal" of the type already described above. On the in Fig. 7 apparent underside of the radiator portion 28d, the refrigerant passages 20d-1 and 20d-2 are subsequently suitably sealed (z. B. by one or more cover plates soldered). The same applies to the through recess 44d.

p0062In the finished electronic unit a flow of the places is 44d, 20d-1 and 20d-2, partially in parallel and partially sequentially, as illustrated by arrows in Fig. 7. One of the panels carries the recess 44d and cools electrolytic capacitors of the circuit arrangement, whereas the refrigerant passages 20d-1, 20d-2 are used for cooling of power electronics parts that are formed of active microelectronic components.

p0063In Fig. 7 can also be seen even "turbulator" structures 38d-1 and 38d-2 to improve the cooling effect or steering the flow of coolant.

p0064FIGS. 8 and 9 finally illustrate an embodiment of a cooler part 28e, wherein similar to the embodiment described above, two flowed successively through coolant passages 20e-1 and 20e-2 are provided.

p0065As in the embodiment described above, this coolant passages 20e are formed as passage openings in the material of the radiator portion 28e. These are 50e by a separate, but common for the two coolant passages cover down towards complete coolant sealing.

p0066The cover 50e is screwed as shown in Fig. 8 visible at screw connection points 52e to the body of the radiator portion 28e (with the interposition of a ring seal).

p0067The seal at this point by a single seal is so far not critical because the electronics compartment is on the cover 50e opposite side of the radiator portion 28e and the electronics compartment is protected by the already above-described concept of a "double seal" reliably against possible leaking coolant.

p0068FIG. 10 illustrates another embodiment of an electronic unit 10f, which is formed using an electronic base plate 16f and a radiator arranged underneath part 28f.

p0069A top 26f of the radiator portion 28f is directly adjacent to a coolant passage 20f, which is limited upwards by a downward-facing surface 18f of the bottom plate 16f. The refrigerant passage 20f is laterally again bounded by the inner side 22f of a closed ring around the coolant passage 20f extending rib 24f.

p0070In the illustrated embodiment of this web 24f integrally formed projecting to the cooler part 28f and upwardly therefrom.

p0071The underside 18f of the base plate 16f is connected to a extending on the free or upper end of the ridge 24f seal 30f coolant sealing the web 24f. The gasket 30f is hereby z. B. from an elastomeric sealing ring, which zwischeng during assembly of the electronic unit 10f is efügt.

p0072In this embodiment, it is essential that in the event of a leak of the coolant passage 20f in the region of the sealing ring 30f leaking refrigerant can not pass directly into the electronic space, since the upper surface 14f of the baseplate 16f coolant sealingly connected to the upper housing structure 32f.

p0073The cooler is part 28f preferably fastened by a screw to the bottom plate 16f, and / or the housing structure 32f, the seal used can be clamped accordingly by this screw as in the above embodiments. For example, screws may be screwed to the underside of the baseplate from below the material of the cooler part by putting in blind holes. In the field of such blind holes, the bottom plate may be increased locally according to their thickness. Alternatively, it is also conceivable to select a total groE SSSR the thickness of the bottom plate.

p0074In this embodiment, coolant inlets and coolant outlets can (z. B. tubular bushings) advantageous to the conditions placed on the cooler part to very freely. One special shaping of the electronics base plate this does not require it. Accordingly, in this embodiment as well as in the embodiments described above generally favorable to provide coolant inlets and coolant outlets to the radiator portion (z. B. by appropriate shaping). Furthermore, it is for the above-described embodiments generally advantageous if the top of the electronics base plate is mostly flat.

p0075Allen embodiments described above have in common is the fact that each coolant passage is sealed so that at overcoming a seal (z. B. is realized by an elastomeric gasket, or soldering), the escaping coolant can not penetrate directly into the electronics compartment. In addition, there is a "direct cooling" in the sense that the underside of the electronic base plate directly contacts the coolant in contact during operation of the electronic unit.