Housing with an electronic assembly arranged inside it

Abstract

Housing (1) with an electronic assembly arranged in its interior (4), comprising at least a lower housing part (2) and a upper housing part (3) which are fluid-tightly connected to each other in edge regions, wherein the lower housing part (2) has an outwardly projecting circumferential rim (5) with a top (6) and a bottom (7) and the upper housing part (3) has an outwardly projecting rim (8) which at least partially surrounds the circumferential rim (5) of the lower housing part (2) and has a first contact area (10) with it on the top (6) of the circumferential rim (5), wherein in the upper surface (6) of the circumferential edge (5) an adhesive-filled circumferential groove (15) is arranged outside next to the first contact area (10), wherein the groove (12) has an asymmetrical shape in cross-section with a shallower wall slope towards the outside.

Description

[0001] The present invention relates to a housing with an electronic assembly arranged inside it, for example a control unit for a motor vehicle.

[0002] Depending on its intended use, an enclosure for an electronic assembly can fulfill various functions. In particular, it protects the electronic assemblies located inside from external influences, especially corrosive substances. For this purpose, the enclosure is designed to be fluid-tight; specifically, the lower and upper parts of the enclosure are fluid-tightly connected.

[0003] Furthermore, a metallic housing can serve as electromagnetic shielding for the electronic components located inside it. Therefore, it is desirable to keep the contact resistance between the lower and upper parts of the housing low.

[0004] It is an object of the present invention to provide a housing with an electronic assembly arranged in its interior, in which the contact resistance between a lower housing part and a housing part is particularly effectively protected against degradation, for example by the influence of corrosive substances. This object is achieved by the subject matter of the independent claim. Advantageous embodiments and further developments are the subject of the dependent claims.

[0005] According to one aspect of the invention, a housing with an electronic assembly arranged inside it is provided, wherein the housing comprises at least a lower housing part and a upper housing part, which are fluid-tightly connected to each other in edge regions. The lower housing part has an outwardly projecting, circumferential rim with a top and a bottom. The upper housing part also has an outwardly projecting rim that at least partially encompasses the circumferential rim of the lower housing part and has a first contact area with it on the upper side of the circumferential rim. In the upper side of the circumferential rim, outside adjacent to the first contact area, a circumferential groove filled with adhesive is arranged, wherein the groove has an asymmetrical cross-sectional shape with a shallower wall slope towards the outside. In other words, the groove has an asymmetrical cross-sectional shape with a wall slope that becomes shallower towards the outside.In other words, the groove has an asymmetrical cross-sectional shape that is flattened outwards or in a direction away from the interior.

[0006] The term "outside" is used in reference to a cross-section of the housing, where, for example, "outwards" indicates a direction away from the interior of the housing, and an arrangement of the groove "outside next to the first contact area" means that the groove is located further away from the interior of the housing than the first contact area.

[0007] Housings often comprise a trough-shaped lower housing section and a lid-like upper housing section. However, housings are also conceivable that have a central body and a lid at each of its two open ends. The teaching described here is also applicable to such housings, whereby the central body is understood as the lower housing section, which can be connected to two upper housing sections in the manner described.

[0008] The housing has the advantage that the first contact area, which is particularly relevant for the electrical contact resistance of the housing, is very well protected against the influence of corrosive substances. This is achieved in particular by the fact that the adhesive-filled groove is positioned between this first contact area and the environment.

[0009] Furthermore, the second contact area is also positioned between the first contact area (the groove) and the environment, thus providing the first contact area with a degree of protection from the effects of corrosive substances. The first contact area is further protected by the groove's asymmetrical cross-sectional shape, which features a shallower outward slope. This causes the adhesive to flow outwards from the groove, away from the first contact area, thereby widening the adhesive seal formed when the lower and upper housing parts are joined, thus improving its sealing effect. The asymmetrical shape of the groove therefore directs the adhesive outwards, away from the first contact area.

[0010] The amount of adhesive applied to the circumferential groove before joining is precisely measured so that, on the one hand, a seal is created when the lower and upper housing parts are joined, meaning the groove is completely filled with adhesive. On the other hand, only a limited amount of adhesive escapes from the groove, preventing the housing parts from being wetted by adhesive in the initial contact area and allowing direct contact between the lower and upper housing parts. This results in low contact resistance in the initial contact area and also provides lasting protection for this area against environmental influences.

[0011] According to one embodiment, the groove transitions outwards into a shallow depression in the top of the circumferential edge, which is at least partially filled with adhesive.

[0012] In this embodiment, the groove transitions outwards, i.e., away from the first contact area, into a recess that is shallower than the groove itself. After the housing parts are joined, adhesive oozes out of the groove because the amount of adhesive introduced into the groove exceeds the groove's volume. This adhesive then flows into the shallow recess, which is subsequently at least partially filled with adhesive.

[0013] This has the advantage that the shallow recess forms a reservoir for adhesive oozing from the groove, allowing for certain tolerances in the amount of adhesive applied. The recess thus absorbs excess adhesive from the groove and prevents it from being forced into the initial contact area and wetting the surfaces to be brought into contact. Furthermore, the recess, which is at least partially filled with adhesive, widens the sealing area and thus improves the seal against environmental influences.

[0014] According to one embodiment, the edge of the upper housing part has a second contact area with the edge of the lower housing part on the underside of the circumferential edge. This embodiment has the advantage that the upper and lower housing parts can be stably connected to each other by plastically deforming the upper housing part.

[0015] According to one embodiment, in the second contact area an outermost edge of the upper housing part is in contact with the lower housing part.

[0016] According to this embodiment, the edge of the upper housing part wraps around the edge of the lower housing part, with its outermost edge coming into contact with the lower housing part on the underside of the edge. This has the advantage that the upper and lower housing parts can be joined together very stably.

[0017] According to one embodiment, the upper and lower housing parts are joined by crimping. Crimping involves joining two or more components through plastic deformation. In particular, the edge of the upper housing part can be deformed during crimping such that it connects to the lower housing part in the first contact area and in the second contact area. The term "crimping" is used here to describe a joining process in which several elements are joined together by plastic deformation, such as flanging or folding.

[0018] According to one aspect, a control unit for a motor vehicle is specified with the described housing. The control unit could be, for example, an engine control unit, a voltage converter, or a high-voltage box of a motor vehicle, but also another type of control unit.

[0019] According to a further aspect of the invention, a method for mounting a control unit is specified, which includes the provision of a housing, wherein the housing comprises at least a lower housing part and a upper housing part which can be fluid-tightly connected to each other in edge regions, wherein the lower housing part has an outwardly projecting, circumferential edge with a top and a bottom, and the upper housing part also has an outwardly projecting edge which can at least partially encompass the circumferential edge of the lower housing part.

[0020] An electronic assembly is inserted into the housing and an adhesive, for example in the form of an adhesive bead, is applied to a circumferential groove in the top of the circumferential edge, the groove having an asymmetrical cross-sectional shape with a shallower wall slope towards the outside.

[0021] The housing is then assembled by placing the upper housing part onto the lower housing part and connecting the lower housing part to the upper housing part, wherein the edge of the upper housing part at least partially surrounds the edge of the lower housing part and has a first contact area on the top of the circumferential edge and optionally also a second contact area on the underside of the circumferential edge, wherein adhesive emerges from the groove arranged outside next to the first contact area and fluid-tightly connects the upper housing part to the lower housing part.

[0022] The lower part of the housing is connected to the upper part of the housing, in particular by means of crimping.

[0023] Embodiments of the invention are described below by way of example with reference to schematic drawings.

[0024] The single figure shows a cross-section through a housing according to one embodiment of the invention.

[0025] Fig. Figure 1 shows a housing 1 of a control unit, comprising a lower housing part 2 and an upper housing part 3, which enclose an interior 4 in which electronic assemblies (not shown) are arranged. The lower housing part 2 and the upper housing part 3 are made of metal, for example, die-cast aluminum or sheet metal, with the upper housing part 3 typically being made of sheet metal.

[0026] The lower housing part 2 has an outwardly projecting, circumferential rim 5 with a top 6 and a bottom 7. The upper housing part 3 also has an outwardly projecting rim 8, i.e., projecting away from the interior 4 in the direction of arrow 14, which at least partially encompasses the rim 5 of the lower housing part 2. An outermost edge 9 of the upper housing part 3 rests on the bottom 7 of the rim 5 of the lower housing part 2.

[0027] The rim 8 of the upper housing part 3 is in close contact with the rim 5 of the lower housing part 2 in at least two areas: a first contact area 10 on the upper surface 6 of the rim 5 and a second contact area 11 on the lower surface 7 of the rim 5. Furthermore, the housing 1 has, according to the Fig.In the embodiment shown in Figure 1, a third contact area 16 is also provided between the first contact area 10 and the second contact area 11, which is also located on the top side 6 of the edge 5, but further outwards than the first contact area 10.

[0028] In the second contact area 11, the outermost edge 9 is in contact with the underside 7 of the rim 5. The connection of the lower housing part 2 with the upper housing part 3 is carried out by crimping, in which the rim 8 of the upper housing part 3 is placed around the rim 5 of the lower housing part 3 and tightly connected to it by plastic deformation.

[0029] In contact areas 10, 11, and 16, an electrical contact is established between the lower housing part 2 and the upper housing part 3. The contact resistance of this contact should be as low as possible for optimal electromagnetic shielding. Therefore, the contact between the lower housing part 2 and the upper housing part 3 is tight and should be protected from corrosion, which would increase the contact resistance over time.

[0030] To seal the housing 1, a groove 12 filled with adhesive 15 is provided in the upper surface 6 of the rim 5, transitioning outwards into a shallow recess 13. The adhesive 15 is applied to the groove 12, for example in the form of a bead of adhesive, before the lower housing part 2 is assembled with the upper housing part 3.

[0031] When the lower housing part 2 is assembled with the upper housing part 3, the adhesive 15 is at least partially squeezed out of the groove 12. Since the groove 12 has an asymmetrical cross-section and a shallower wall slope on the outside than on the inside, the adhesive 15 does not flow inwards towards the first contact area 10, but preferentially towards the shallow recess 13. Therefore, the lower housing part 2 and the upper housing part 3 remain free of adhesive in the first contact area 10.

[0032] The groove 12 filled with adhesive 15 is located on the outside next to the first contact area 10 and thus protects the first contact area 10 from environmental influences. Reference symbol list 1 case 2 Housing lower part 3. Upper housing 4 Interior 5 Rand 6 Top 7 Underside 8 rand 9 edge 10 first contact area 11 second contact area 12 Nut 13. Further Study 14 Arrow 15 adhesive 16 third contact area

Claims

Housing (1) with an electronic assembly arranged in its interior (4), comprising at least a lower housing part (2) and a upper housing part (3) which are fluid-tightly connected to each other in edge regions, wherein the lower housing part (2) has an outwardly projecting circumferential rim (5) with a top (6) and a bottom (7) and the upper housing part (3) has an outwardly projecting rim (8) which at least partially encompasses the circumferential rim (5) of the lower housing part (2) and has a first contact area (10) with it on the top (6) of the circumferential rim (5), wherein in the top (6) of the circumferential rim (5) an adhesive-filled circumferential groove (12) is arranged outside next to the first contact area (10), wherein the groove (12) has an asymmetrical shape in cross-section with a shallower wall slope towards the outside. Housing (1) according to claim 1, wherein the groove (12) transitions outwards into a flat recess (13) in the top surface (6) of the circumferential rim (5), which is at least partially filled with adhesive (15). Housing (1) according to claim 1 or 2, wherein the rim (8) of the housing upper part (3) has a second contact area (11) on the underside (7) of the circumferential rim (5) with the rim (5) of the housing lower part (2). Housing (1) according to claim 3, wherein in the second contact area (11) an outermost edge (9) of the housing upper part (3) is in contact with the housing lower part (2). Housing (1) according to one of claims 1 to 4, wherein the housing upper part (3) and the housing lower part (2) are connected to each other by crimping. Control unit for a motor vehicle with a housing (1) according to one of claims 1 to 5 . Method for assembling a control unit according to claim 6, comprising: - providing a housing (1) comprising at least a lower housing part (2) and an upper housing part (3) which can be fluid-tightly connected to each other in edge regions, wherein the lower housing part (2) has an outwardly projecting, circumferential rim (5) with a top (6) and a bottom (7) and the upper housing part (3) has an outwardly projecting rim (8) which can at least partially encompass the circumferential rim (5) of the lower housing part (2); - inserting an electronic assembly into the housing (1);- Introducing an adhesive (15) into a circumferential groove (12) in the upper surface (6) of the circumferential rim (5), wherein the groove (12) has an asymmetrical cross-sectional shape with a shallower wall slope towards the outside; - Assembling the housing (1) by placing the upper housing part (3) onto the lower housing part (2) and connecting the lower housing part (2) to the upper housing part (3), wherein the rim (8) of the upper housing part (3) at least partially surrounds the rim (5) of the lower housing part (2) and has a first contact area (10) with it on the upper surface (6) of the circumferential rim (5), wherein adhesive (15) emerges from the groove (12) arranged outside next to the first contact area (10) and seals the upper housing part (3) to the lower housing part (2) in a fluid-tight manner. Method according to claim 7, wherein the connection of the lower housing part (2) to the upper housing part (3) is carried out by crimping.

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