DE202010018233U1 - Electric device - Google Patents

Abstract

An electric device comprising - a subassembly (1) having a support (2) and electrical components (3-8), the components (3-8) being fastened to and protruding from the support (2) at predetermined positions, with the assembly (1) fixedly connected to this one distance (13) having, the components (3-8) covering and with recesses (15-19) provided with protective body (12), wherein the recesses (15-19) the predetermined Positions are arranged opposite one another, so that the components (3-8) in the recesses (15-20) immerse, - one in the distance (13) between the protective body (12) and the assembly (1) arranged and both with the protective body (12) as well as with the assembly (1) in contact, elastic intermediate layer (24), characterized in that the intermediate layer (24) serves as a spacer between the assembly (1) and the protective body (12), so that a direct Contact of carrier (2) and Protective body (12) is prevented, wherein the intermediate layer (24) at least partially fills the distance between the protective body (12) and the carrier (2) and is in contact both with the protective body (12) and with the carrier (2) ,

Description

The invention relates to an electrical device comprising a carrier and electrical components comprehensive assembly, wherein the components are fixed to predetermined positions on the carrier and protrude from this, one firmly connected to the assembly, this having a distance, the components covering and with Recessed protective body, wherein the recesses are arranged opposite to the predetermined positions, so that the components are immersed in the wells, and arranged in the distance between the protective body and the assembly and in contact with both the protective body and with the assembly intermediate layer.

The sealing of components having electrical components from their environment, so that protection against moisture, high temperatures and damage caused by vibrations is known from the prior art. Such protection is z. B. achieved by an electrically insulating protective body, which is connected to the module and covers the components. The method for applying such a protective body to the assembly or for introducing the assembly into such a protective body is referred to as potting or encapsulation.

The electrical components are usually soldered to a circuit board, z. B. via vias or Oberflächenkontaktierungen. In the simplest form of the potting process, the assembly is positioned in a mold which is poured with a resin, thereby completely enclosing the components of the resin. After curing of the resin, a hard and durable protective body is formed around the components. The mold can form a housing and remain permanently connected to the protective body.

In other potting methods, the mold is removed after curing of the resin and can be used for other assemblies. As another way to protect electrical components, a so-called "dip coating" or dip coating is known, in which the assembly is immersed in a bath of resin, so that a thick and hard protective layer is produced on the components, which forms the protective body and completely encloses the assembly.

However, the potting process involves some difficulties, such as unwanted and harmful influences on the components. For example, undesirable pressures and mechanical stresses caused by the shrinkage process during curing of the resin may occur. Also, the components can be damaged by high temperatures that occur due to exothermic processes during curing of the resin. Furthermore, mechanical stresses acting on the components, which are caused by a different thermal expansion behavior of printed circuit board, components and cured resin, are detrimental. Likewise, changes in the electrical properties of the components may occur, for. Example, when resin penetrates into air gaps of transformers, coils or other electrical components, the functionality of which depends on the magnetic permeability of the air gaps, since the resin has a different permeability than air in the rule. Changes in the electrical properties of devices may also occur due to shrinkage of the resin during cure or thermal expansion of the resin during operation when the devices are pressure sensitive. Pressure sensitive components are z. B. quartz crystals, glass-clad reed relays and spools made of iron powder. Finally, the components may be damaged by chemical by-products forming during curing. Mechanical stresses lead in particular to damage in surface-mounted components (SMD components), which can be easily separated from the circuit board due to their relatively weak solder joint. Furthermore, the potting method can not be used if the printed circuit board has cable connectors, since penetration of the resin into the connectors could block movable parts thereof and thus impair the function of the connectors.

The US Pat. No. 6,583,355 B2 describes a printed circuit board, which is arranged in a housing and is enclosed there by a protective cover. To avoid mechanical stresses, a bladder is disposed in the housing that is compliant and enclosed by the protective sheath.

Mechanical stresses that occur during the manufacture of the protective cover can be compensated by the bladder positioned in the protective cover.

An encapsulated circuit is further disclosed in U.S. Patent Nos. 5,194,954 DE 42 24 122 A1 described, wherein the circuit is completely enclosed by a potting compound. To reduce unwanted stresses that occur during curing of the potting compound, a buffer element is disposed within the potting compound.

Although mechanical stresses are reduced with the compensation means developed in the prior art, these are not excluded. In particular, it has been found That these compensation means can not compensate for mechanical stresses to a sufficient extent, so that a deterioration of the serviceability of the components can not be reliably prevented.

These problems are partially solved by a method according to the US Pat. No. 6,035,524 according to which a protective body, which simultaneously forms a heat sink, is not produced by casting over the printed circuit board, but separately from it. The protective body has recesses assigned to the components and is connected to the assembled printed circuit board in such a way that the components dip into the recesses. Further, the protective body to the circuit board and the components at a distance which is filled with an electrically insulating, good heat conducting and adhesive interlayer. This intermediate layer forms a thermal coupling between the components and the protective body and consists for. As mastic, resin, paint, lubricant or gel.

However, a different thermal expansion behavior of the protective body and printed circuit board still entails the risk that local mechanical stresses occur on the components, which can lead to damage or impairment of the functionality of the components.

It is therefore an object of the invention to provide a means for encapsulating the assembly having the electrical components, wherein the occurrence of mechanical stresses in the area of the components due to a different thermal expansion behavior of the carrier and protective body can be avoided or at least reduced.

This object is achieved with a device according to claim 1. Preferred developments of the invention are given in the dependent claims.

The electrical device according to the invention has a carrier and electrical components having assembly, wherein the components are fixed at predetermined positions on the carrier and protrude from this, one with the assembly firmly connected to this distance having, the components covering and provided with recesses Protection body, wherein the recesses are arranged opposite the predetermined positions, so that the components are immersed in the wells, and arranged in the distance between the protection body and the assembly and in contact with both the protective body and the assembly in the intermediate layer, the elastic is formed and serves as a spacer between the assembly and the protective body, so that a direct contact of the carrier and the protective body is prevented, wherein the intermediate layer at least partially fills the distance between the protective body and the carrier and so probably in contact with the protective body as well as with the carrier.

According to the invention an elastically formed intermediate layer is provided in the distance between the assembly and the protective body, which elastically deforms when forces are introduced into the intermediate layer. The intermediate layer thus forms a buffer for mechanical stresses that occur due to different thermal expansions of assembly and protective body. At the same time, the intermediate layer serves as a spacer between the assembly and the protective body, so that direct contact between the carrier and the protective body is prevented. Damage and functional impairment of the components due to a different thermal expansion behavior of the carrier and protective body are thus avoided or at least noticeably reduced.

The components are preferably arranged spaced apart on the carrier. Preferably, the components are arranged on the same side of the carrier. In particular, the components protrude in the same direction from the carrier. According to one embodiment of the invention, the carrier is plate-shaped or at least partially plate-shaped. In particular, the carrier is a printed circuit board with which the components are preferably electrically connected, for example by solder joints.

The depressions are assigned in particular to the components. A front side of the protective body facing the carrier and provided with the depressions preferably follows or preferably follows at least approximately a spatial structure formed by the carrier and the components. In particular, the recesses have such dimensions that at least one or more of the components or the components to the protective body at a distance, in particular a circumferential distance. Preferably, at least one or more of the or the components further comprises a frontal distance to the protective body. This ensures that the components are not in direct contact with the protective body, or only to a small extent. This also can be kept away from the components mechanical stresses or at least significantly reduced, which are due to a different expansion behavior of the assembly and protective body.

According to one embodiment of the invention, the circumferential distance between one of the components and the protective body is different from the circumferential distance between another of the components and the protective body. A larger circumferential distance between one of the components and the protective body can, for. B. be used as a thermal barrier when as little heat from this device to be delivered to the protective body. Furthermore, the frontal distance between one of the components and the protective body may be different from the frontal distance between another of the components and the protective body.

Preferably, the intermediate layer fills the gap between the assembly and the protective body partially or at least partially. In particular, the intermediate layer is in contact with the carrier, with the protective body and preferably also with at least one or more of the components or components. The at least one or the components in contact with the intermediate layer are preferably fixed and / or stabilized and / or secured and / or centered by the intermediate layer. Thus, protection of the at least one or the components in contact with the intermediate layer before local mechanical stresses can be achieved. Advantageously, the intermediate layer is provided at the front of the protective body at least in areas between the recesses. Preferably, the intermediate layer extends into at least one or more of the or in the wells, in particular at least at the edge.

According to one embodiment of the invention, the intermediate layer extends into at least one or more of the or in the circumferential distances. Preferably, the intermediate layer extends into at least one or more of the or in the frontal distances. Preferably, at least one or more of the components or components is connected to the protective body via the intermediate layer.

The intermediate layer preferably has a good thermal conductivity, so that heat can be emitted from at least one or more of the components or from the components and / or from the carrier into the protective body. According to one embodiment of the invention, the protective body forms a heat sink or a thermal coupling member to a heat sink. Thus, by means of the intermediary of the intermediate layer, the assembly can be cooled.

For components that produce a lot of heat, such. As power transistors, the thermal coupling over the intermediate layer but can cause problems. These components may overheat during operation if not enough heat is dissipated. Furthermore, these components can heat the protective body at least in regions such that other components are thermally overloaded. Also, it can not be ruled out that the material of the intermediate layer creeps into the interior of connectors and thus blocks moving parts thereof.

Thus, at least one of the recesses into which at least one of the components is immersed is preferably free or substantially free of the intermediate layer. This ensures that the at least one component immersed in this depression is not in contact with the intermediate layer. Preferably, at least one or more of the components is thus not in contact with the intermediate layer. The disadvantages associated with the intermediate layer or with the material of the intermediate layer in some components can thereby be avoided. Furthermore, this at least one depression is preferably dimensioned so large that the component immersed in this depression is positioned at an all-round distance from the protective body. As a result, as already mentioned above, a thermal barrier to the protective body can be formed.

However, preferably at least one (other) of the recesses into which at least one (another) of the components is immersed is provided with the intermediate layer. In particular, in this case, the at least one (other) component is in contact with the intermediate layer. Thus, it is possible depending on the nature of the components to take advantage of the intermediate layer and to avoid disadvantages of the intermediate layer. The intermediate layer thus does not have to be formed over its entire area between the assembly and the protective body. In particular, it is sufficient to provide the intermediate layer at a plurality of spaced-apart locations.

Furthermore, there is the problem that some components, such. B. electrolytic capacitors, have ventilation holes that can be clogged by the material of the intermediate layer. At high load of these components then formed gases can not be dissipated to the outside, which can lead to the destruction of the components. Preferably, a free space is thus provided between at least one of the components and the carrier, which is free of the intermediate layer. If the component is an electrolytic capacitor which has a ventilation hole on its side facing the carrier, then gas can be released into the clearance.

Additionally or alternatively, a front-side free space is preferably provided between at least one of the components and the bottom of the associated recess, wherein the bottom of the recess is free of the intermediate layer. If the component is an electrolytic capacitor which has a ventilation hole on its side facing away from the carrier, then gas can be released into the frontal space.

As already mentioned above, the front side of the protective body facing the carrier and provided with the depressions preferably follows at least approximately the spatial structure formed by the carrier and the components. In particular, the components form elevations on the carrier, to which the protective body has the depressions in a complementary manner. To ensure complete encapsulation of the components of the protective body is thus adapted to the shape of the module.

Preferably, the circumferential contours of the recesses follow at least approximately the circumferential contours of the components. Preferably, at least one or more of the depressions or depressions are dimensioned such that an all-round distance remains between at least one or more of the structural elements and the protective body. The protective body is preferably spaced differently far from the components. The depressions are dimensioned in particular depending on the size of the components.

Preferably, the recesses in the protective body are also adapted to the function and / or to the heat development of the components with regard to their dimensioning. In a component with greater heat development, for example, the associated recess can be made larger, so that a larger space or distance to the protective body is formed.

The components preferably protrude perpendicularly or substantially perpendicularly from the carrier. The depressions preferably run straight or substantially straight. Thus, a simple introduction of the components in the wells is possible. Preferably, the peripheral walls delimiting the depressions or some of the depressions extend perpendicularly or substantially perpendicular to the carrier.

The depressions in particular have a distance from one another. Preferably, one or at least one of the components is arranged in each of the recesses. Furthermore, it is possible for two or more components to be arranged in at least one of the depressions. This is advantageous if these two or more components are arranged relatively close to each other on the carrier. The recess can then have different depths, which are adapted to the respective component.

The lying between the wells areas of the front of the protective body are preferably adapted to the course of the wearer. In particular, the lying between the recesses areas of the front of the protective body lie on a plane.

The intermediate layer preferably fills in part or at least in part the distance between the protective body and the carrier and is preferably in contact both with the protective body and with the carrier. Preferably, in at least one of the recesses, the intermediate layer additionally fills in part or at least in part the distance between the protective body and the component associated with this recess. Preferably, the intermediate layer is in contact with the component and the protective body. Thus, the intermediate layer is preferably in contact with the carrier, the protective body and the component.

The intermediate layer preferably ensures the distance between the assembly and the protective body and thus serves as a spacer. Preferably, the intermediate layer is arranged only in the areas in which it is expedient. According to one embodiment of the invention, only a portion of the distance between the protective body and the carrier and / or the components may be filled with the intermediate layer, preferably only as far as it is to ensure the distance between the assembly and the protective body and / or a desired heat transfer between the assembly and the protective body and / or a desired sealing of the components is beneficial to the outside. Thus, enough space can be made available for the components. In particular, not every type of component requires the same distance to the protective cover.

Preferably, the components are encapsulated by the carrier, the protective body and the intermediate layer and preferably also sealed to the outside. Since the protective body is preferably adapted to the spatial structure formed by the carrier and the components and the intermediate layer preferably also assumes the sealing function in addition to the elastic buffer function, this encapsulation and sealing to the outside is relatively easy.

According to one embodiment of the invention, a protective body on the back is provided, wherein the protective body by at least one mechanical Fasteners, such. As a screw, are firmly connected. The assembly is arranged in particular between the protective bodies. Furthermore, an elastic layer can be provided between the back protection body and the assembly.

The protective body is preferably fastened to the carrier by at least one fastening means. The fastener may, for. B. be formed by the intermediate layer or include these. Preferably, the protective body is attached by means of the intermediate layer to the module. In particular, the protective body is fastened to the carrier and / or to at least one or more of the components by means of the intermediate layer. Preferably, the protective body is glued to the assembly by means of the intermediate layer. In particular, the protective body is adhesively bonded to the carrier and / or to at least one or more of the components by means of the intermediate layer. The intermediate layer preferably has adhesive properties for this purpose. With such an intermediate layer, the encapsulation of the components can be achieved in a simple manner, since additional fastening means are not absolutely necessary. Additionally or alternatively, the protective body to the assembly by at least one mechanical fastening means, such. As a screw attached. In particular, the protective body may additionally or alternatively be fastened to the carrier and / or to at least one or more of the components by the at least one mechanical fastening means. The one or more fastening means are also preferably used as spacers, in particular for maintaining the distance between the assembly and the protective body.

The intermediate layer is z. B. formed by an elastomer. In particular, the intermediate layer is formed by a silicone elastomer or by a silicone-based elastomer. With such an elastomer bonding of the protective body with the module is possible. Alternatively, a rubber may also be used as the elastomer. In this case, the at least one mechanical fastening means is preferably used. The intermediate layer is preferably electrically insulating. In particular, the carrier and / or the assembly is electrically isolated from the protective body by means of the intermediate layer. Furthermore, the intermediate layer is preferably thermally conductive. In particular, the carrier and / or the assembly is thermally coupled to the protective body by means of the intermediate layer.

According to one embodiment of the invention, the bottom of at least one of the recesses is in heat-conducting contact with the component arranged in this recess. Thus, a direct cooling of this device by the protective body is possible. This embodiment is useful for components with a greater heat development.

Preferably, the arrangement formed by the assembly and the protective body is completely or at least partially surrounded by a sheath. The sheath provides additional protection of the components, for example from moisture and / or externally introduced vibrations. Thus, use of the electrical device is possible even in extremely adverse weather and environmental conditions. The casing is preferably produced in the casting process from a potting compound, which cures in particular after casting. Thus, the arrangement is preferably completely or at least partially encapsulated by the sheath.

If the term "potting compound" is used, it is preferably a mass that is liquid during casting and then cured or cured. The cured potting compound preferably forms a solid and / or substantially solid and / or dimensionally stable and / or substantially dimensionally stable material. As potting compound, for example, a polyurethane or an epoxy resin can be used. Depending on the application can be used as potting z. But also a polyamideimide, a metal or another material can be used.

According to one embodiment of the invention, the arrangement formed by the assembly and the protective body is introduced into a container.

Preferably, the protective body has a through opening opening into one of the recesses, into which, in particular, a cooling body is introduced, which is in heat-conducting contact with the component arranged in this recess. This is useful for a device with a large heat generation, such. As a power transistor or a power transistor arrangement, in particular when the heat produced by the device is not to be introduced into the protective body. Preferably, a projection of the container, which is in particular in heat-conducting contact with the component, extends into the through opening, so that the projection forms the heat sink. The heat sink is preferably metallic.

According to one embodiment of the invention, the arrangement is arranged at a distance or at least partially spaced from the walls of the container and completely or at least partially surrounded by the sheath, which is provided between the assembly and the walls of the container. The sheath is preferably by Pouring the distance between the assembly and the walls of the container made with the potting compound.

The container preferably forms a housing, which in particular provides additional protection for the components. For example, an electrical shielding of the components can be realized via the container. The container consists z. As plastic or metal, especially aluminum or steel, such as. B. stainless steel.

The term "electrical components" also includes electronic components. Furthermore, an electrical component may comprise one or more electrical and / or electronic components.

The protective body is preferably a solid or substantially solid body. For example, the protective body consists of an epoxy resin, polyamide imide or metal, such as. As aluminum.

Preferably, the electrical device and / or the arrangement formed by the carrier and the components is arranged on or in a rotor of a wind turbine and preferably forms a control or at least part of a control of a Blattwinkelverstellantriebs, by means of which one or at least one rotor blade of the rotor relative to a rotor hub of the rotor can be rotated, on which the rotor blade is rotatably mounted. The Blattwinkelverstellantrieb in particular comprises one or at least one electric motor, with which the electrical device and / or the arrangement is preferably electrically coupled.

Preferably, the electrical device and / or the arrangement is attached to the electric motor. The electrical device and / or the arrangement preferably comprises one or at least one converter which is electrically connected to the electric motor and has at least one or more of the components or components. The protective body is preferably produced separately from the assembly, in particular before it is connected to the protective body.

According to one embodiment of the invention, the intermediate layer between the protective body and the components and / or the carrier is provided. Before connecting the protective body to the assembly, the intermediate layer is preferably applied to the protective body. Preferably, the protective body is then placed with the intermediate layer on the assembly or the assembly is placed on the intermediate layer. Preferably, the distance between the protective body and the assembly is ensured by the intermediate layer, which thus forms a spacer.

According to a further embodiment of the invention, the intermediate layer is applied to the protective body in at least one area. The intermediate layer is preferably applied on a front side of the protective body in regions between the depressions and is preferably introduced into at least one of the depressions, at least peripherally.

The recesses are preferably assigned to the components. In particular, the recesses are provided in the protective body at positions which are assigned to the predetermined positions. Preferably, the protective body is adapted to the spatial structure formed by the carrier and the components or at least approximately adapted, preferably in a complementary manner. Thus, the components can immerse in connecting the assembly with the protective body in the wells. Advantageously, the protective body is produced by casting, pressing, machining, milling or the like.

According to one embodiment of the invention, the components are encapsulated by the joining or merging of the protective body with the assembly and preferably further sealed to the outside. In particular, the intermediate layer is brought into contact with the carrier. Preferably, the intermediate layer is further contacted with at least one or more of the components. Additionally or alternatively, the intermediate layer is preferably not brought into contact with at least one or more (other) of the components.

Preferably, the intermediate layer is provided in at least one region or in several regions in the distance between the protective body and the assembly. The intermediate layer, in particular in the region of the components, is preferably brought into contact with the protective body and the carrier and preferably also with at least one or more of the components or components. Transitions between areas can be seamless or intermittent.

Preferably, the assembly formed from the assembly and the protective body connected thereto is provided with a sheath which surrounds the arrangement completely or at least partially and preferably seals to the outside. In particular, the arrangement formed from the assembly and the protective body connected thereto is completely or at least partially encapsulated with a potting compound, which preferably forms the casing after it has hardened. In particular, the potting compound does not come into contact with the electrical components, so that no Damage or functional impairment of the components may occur through the potting compound.

According to one embodiment of the invention, the arrangement formed from the assembly and the protective body connected thereto is introduced into a container and preferably connected by at least one fastening means to the container. The fastening means comprises, for example, an adhesive and / or a mechanical fastening means, such. B. a screw.

The arrangement is preferably arranged at a distance or at least in regions spaced from walls of the container. The at least one fastening means preferably also serves as a spacer. In particular, the distance between the arrangement and the walls of the container is poured with the potting compound. Thus, the assembly is completely or at least partially enclosed by the potting compound, which forms the shell after curing. The container preferably forms a mold. In particular, the container forms a housing.

According to a first variant of the invention, the arrangement provided with the jacket remains in the container.

According to a second variant of the invention, the arrangement provided with the sheath is removed from the container. Subsequently, the arrangement provided with the sheath is preferably installed in a housing, which is provided in particular in addition to the container.

The housing, regardless of whether it is formed by the container or provided in addition to this, serves in particular for better shielding of the assembly from its surroundings and thus provides additional protection.

According to an alternative, a mask which simulates or at least approximately reproduces the spatial structure formed by the carrier and the components is produced, and the protective body is manufactured using the mask. Preferably, the mask is arranged in a mold and preferably connected by at least one fastening means with the mold. The fastening means is in particular detachable and comprises, for example, a mechanical fastening means, such. B. a screw. The mask in particular represents one or approximately a positive impression of the carrier with the components. The mask is preferably arranged at a distance or at least in regions at a distance from walls of the casting mold, wherein the at least one fastening means preferably also serves as a spacer.

After arranging the mask in the mold, it is preferably poured out with a potting compound, which then hardens. After curing of the potting compound, the mask is removed from the mold, wherein the cured potting compound forms the protective body. Furthermore, the protective body can be removed from the mold. However, the casting mold preferably forms a housing, so that the protective body can remain in the casting mold.

Subsequently, the intermediate layer is applied to the protective body and / or the assembly and the assembly connected to the protective body and / or the housing. In particular, the assembly is introduced into the housing. Preferably, the assembly is applied to the intermediate layer and connected to the protective body, so that the components dive into the wells and the intermediate layer is brought into contact with the carrier. If the casting forms a housing, then it is in particular firmly connected to the arrangement formed by the assembly and the protective body.

The process with the help of the mask ensures that no damage or functional impairment of the components are caused, which are due to the potting compound. When casting the mold is encased by the potting compound only the mask, the stresses may be exposed during curing of the potting compound.

For producing the mask can, for. B. the spatial structure formed by the carrier and the components are scanned. Based on the information obtained by the scan then the mask can be made. But is already a negative impression of the module, such. As a protective body, present, it can be used in a mold, after which the mask is made by introducing a potting compound into the mold.

The assembly formed from the assembly and the protective body connected thereto is preferably mounted on or in a rotor of a wind turbine. Preferably, the arrangement is surrounded by the sheath and / or arranged in the housing. In particular, the assembly is electrically coupled to a blade angle adjustment drive disposed on or in the rotor, by means of which a rotor blade of the rotor is preferably rotated relative to a rotor hub of the rotor on which the rotor blade is or will be rotatably mounted. Preferably, the assembly is also mechanically coupled to a motor of the Blattwinkelverstellantriebs.

The invention will be explained below with reference to preferred embodiments with reference to the drawing. In the drawing show:

1 a partially sectioned side view of an assembly with a support and thereon arranged electrical components,

2 a partially sectioned side view of the assembly according to 1 and a protective body adapted to the spatial structure of the assembly,

3 the view after 2 with an intermediate layer applied to the protective body,

4 the view after 3 in which the assembly with the protective layer coated with the intermediate layer is connected to an arrangement according to a first embodiment of the invention,

5 a partially sectioned side view of the arrangement according to 4 in a state brought into a housing,

6 the view after 5 wherein the housing is poured with a potting compound,

7 a partially sectioned side view of an arrangement according to a second embodiment of the invention,

8th a partially sectioned side view of a housing arranged in a mask,

9 the view after 8th , wherein the housing is poured with a potting compound and

10 the view after 9 , wherein the mask by an assembly according to 1 has been replaced.

From the 1 to 6 is a method for encapsulating electrical components according to a first embodiment of the invention can be seen. An assembly 1 includes a carrier 2 in the form of a printed circuit board with electrical components arranged thereon 3 to 8th , The individual components are spaced from each other on the circuit board 2 arranged and illustrate the diversity of electrical components that can be installed on the circuit board. The component 3 puts a transformer with louvres 9 which are preferably to remain free of foreign material. The component 4 is a connector. The component 5 is an electrolytic capacitor that is spaced from the circuit board 2 is arranged, leaving a free space 10 between the capacitor 5 and the circuit board 2 is provided. The capacitor 5 is on the circuit board 2 attached with connecting wires and preferably has a ventilation hole in the area. The component 6 is a diode with a glass housing, which may only be exposed to low mechanical loads. The component 7 is an SMD card. Furthermore, the component forms 8th a transistor arrangement, in particular an IGBT module, which has a surface 11 can be cooled.

When referring hereinafter to "the" component or "the" components, what has been said preferably relates to any of the components described above 3 to 8th unless it is explicitly referred to a particular device.

To protect the components against environmental influences is a protective body 12 with the carrier 2 connected so that the components between the carrier 2 and the protective body 12 encapsulated and thereby protected. The protective body 12 becomes so with the carrier 2 connected that a distance 13 between the carrier 2 the protective body 12 remains. Furthermore, circumferential distances 14 and frontal distances 37 between the components and the protective body 12 intended. Thus, the protective body touches 12 neither the carrier 2 nor the components directly.

The protective body 12 is to one by the wearer 2 and the components formed spatial structure of the assembly 1 customized. In particular, the protective body 12 wells 15 to 19 on, which correspond approximately to the sizes and shapes of the components. In particular, the depression serves 15 for receiving the device 3 , the recess 16 for receiving the device 4 , the recess 17 for receiving the device 5 and the depression 19 for receiving the device 8th , Furthermore, the depression serves 18 for receiving the components 6 and 7 so that the depression 18 a common recess for the components 6 and 7 forms. Each of the recesses is formed larger than the respectively associated component or the respective associated components.

In the distance 13 between the protective body 12 and the carrier 2 as well as in the depressions 15 . 17 and 18 , between the protective body 12 and the components 3 . 5 . 6 and 7 , is an elastic intermediate layer 24 provided by means of which the assembly 1 with the protective body 12 connected is. On the other hand, the depressions 16 and 19 free or substantially free of the intermediate layer 24 , Further, the bottom of the recess 17 free from the interlayer 24 , Also, the recess 15 in the area of the louvers 9 free from the interlayer 24 , Thus, the distance between the assembly 1 and the protective body 12 only partially with the intermediate layer 24 filled out, inter alia, as a spacer between the assembly 1 and the protective body 12 serves.

As already mentioned above, some of the recesses are free or at least partially free of the intermediate layer 24 , The between the component 4 and the protective body 12 enclosed space 21 in the depression 16 is free or substantially free of the interlayer 24 so that no material of the intermediate layer in the connector 4 can penetrate and block moving parts of the same. The between the component 5 and the protective body 12 enclosed space 22 in the depression 17 is free or substantially free of the interlayer 24 so that this one in the capacitor 5 frontal provided ventilation hole can not clog. The between the component 8th and the protective body 12 enclosed space 23 in the depression 19 is free or substantially free of the interlayer 24 so that these no thermal bridge between the device 8th and the protective body 12 can form. Further, in the depression 19 the circumferential distance 14 larger than the other recesses for creating a thermal barrier, so that of the device 8th delivered heat in the smallest possible extent in the protective body 12 is initiated.

The intermediate layer 24 is thus only partially between the module 1 and the protective body 12 arranged. In particular, some depressions are free or at least partially free of the intermediate layer 24 if it is useful for the functioning of the components arranged in these recesses.

The one to the by the carrier 2 and the components formed spatial structure adapted protective body 12 is produced in a preliminary process. For example, the protective body 12 by casting, machining, pressing, milling and / or other forming processes. The protective body 12 thus becomes separate from the assembly 1 made, and before that with the protective body 12 is connected.

The from the assembly 1 and the protective body connected thereto 12 formed arrangement 20 gets into a housing 25 used, being between the arrangement 20 and the walls of the housing 25 partially a distance 30 remains. A lead 27 of the housing 25 extends through a through opening 28 in the protective body 12 through, into the depression 19 passes. The lead 27 lies on the surface 11 of the component 8th and serves as a heat sink for the device 8th , Further, the assembly is 1 and therefore also the arrangement 20 by mechanical fasteners 26 , here in the form of screws, with the projection 27 and therefore also with the housing 25 firmly connected.

Complementary or alternative to the mechanical fasteners 26 can the arrangement 20 also by an adhesive 29 on the housing 25 be attached. The between the arrangement 20 and the walls of the housing 25 formed distance or gap 30 comes with a potting compound 31 filled, where also the protective body 12 opposite side of the carrier 2 from the potting compound 31 is covered. After curing of the potting compound 31 is the arrangement 20 permanently encapsulated in the potting compound. This is off 6 It can be seen that an electrical device 38 according to a first embodiment of the invention.

Due to the separate production of the protective body 12 can be used for this different materials with different properties. For example, as a material for the protective body 12 an epoxy resin, in particular a 2-component epoxy resin are used, which z. B. a modulus of elasticity of E = 2.7 MPa, a yield strength of E_Flow = 20 MPa, a working temperature of T = -40 to 150 ° C, a glass transition temperature of about 60 ° C and a thermal expansion coefficient of Tg = 80 ppm / K (instead of ppm / K also μm / m / K is written). The thermal expansion coefficient of the carrier or circuit board material is preferably in a range of 20 to 30 ppm / K. The value of 80 ppm / K of the epoxy resin is reasonably close to the value of 30 ppm / K, so that differences in material expansion remain relatively small when the temperature during operation is subjected to relatively small fluctuations (for example, between 0 and 40 ° C) ) and remains below the glass transition temperature Tg of the epoxy resin. The thermal conductivity of the epoxy resin is in particular 0.18 W / (m · K) and its dielectric strength in particular at 16 kV / mm. Furthermore, the water absorption capacity of the epoxy resin is preferably very low. Such an epoxy resin forms a good potting material and is known in the art.

A more suitable material for the protective body 12 However, it is polyamide-imide (PAI), for example, the 4275th This is in particular a polyimide with 20% graphite and 3% polytetrafluoroethylene (PTFE). This material has a thermal expansion coefficient of 25 ppm / K, which is close to the value of 20 ppm / K of the printed circuit board material, so that due to temperature fluctuations almost no relative movements between the carrier 2 and the protective body 12 and thus almost no mechanical Tensions occur. In addition, PAI retains high strength over a temperature range of -190 to 260 ° C and has a very good dielectric strength. Furthermore, PAI has a glass transition temperature of 275 ° C and can therefore be used even at the highest working temperatures of electrical components.

However, due to the high viscosity and melting temperature of over 200 ° C of PAI, this material can not be used in a normal casting process in which the components can make closer thermal contact with the potting compound. As a result, the protective body becomes 12 manufactured separately, without touching the electrical components. For producing the protective body 12 known manufacturing methods can be used, such. B. also injection molding. The separate production of the protective body 12 is referred to as pre-potting.

Hereinafter, the manufacturing method according to the first embodiment will be described.

The assembly 1 is made by placing the components on the carrier 2 be attached. The assembly 1 is z. B. off 1 seen. The protective body 12 will be separate from the assembly 1 made and to the by the carrier 2 and the components formed spatial structure of the assembly 1 customized. Thus, the protective body 12 the wells 15 to 19 on, in which the on the carrier 2 arranged components can dip what made 2 is apparent. According to 3 is then on the surface of the protective body 12 the elastic intermediate layer 24 applied with adhesive properties, by means of which the carrier 2 with the protective body 12 permanently connected, what is out 4 is apparent. This is what the intermediate layer represents 24 prefers a desired distance between the carrier 2 and the protective body 12 for sure.

As a preferred material for the intermediate layer 24 For example, a silicone elastomer or silicone-based elastomer is used which has a low viscosity before curing and a high flexibility (low modulus of elasticity) after curing, a high dielectric strength and a low coefficient of thermal expansion. For example, such an elastomer has a viscosity of 2850 mPA · s, a hardness of 45 Shore A after curing, and a thermal expansion coefficient of 250 ppm / K

After connecting the protective body 12 with the carrier 2 is the resulting arrangement 20 waterproof and can thus survive unscathed use in a humid environment. Furthermore, the arrangement 20 Resistant to vibration and other external influences. The arrangement preferably forms a coherent, in particular monolithic structure.

Due to the high dielectric strength of the intermediate layer 24 and due to the electrically insulating properties of the intermediate layer 24 can the protective body 12 also have metallic material or consist of metallic material. In this case, the protective body 12 an external housing for the module 1 and / or the components form or the function of an external housing for the assembly 1 and / or take over the components. The metallic material is or preferably comprises aluminum.

According to 5 becomes the composite arrangement 20 in the case 25 introduced, the arrangement 20 through the fasteners 26 and / or the adhesive 29 who is on a spacer 39 is applied in the housing 25 is attached. The order 20 is at a distance or at least partially spaced from the walls of the housing 25 positioned. The protective body 12 points in the area of the component 8th the continuous recess 28 on, leaving the device 8th with the lead 27 of the housing 25 is brought into contact. According to 6 becomes the case 25 with a liquid potting compound 31 poured, which consists for example of a polyurethane or an epoxy resin. After curing of the potting compound 31 form the housing 25 , the potting compound 31 and the arrangement 20 a coherent, in particular monolithic structure.

Alternatively to a silicone-based elastomer may also be another elastic and / or elastomeric material for the intermediate layer 24 be used. For example, the intermediate layer 24 made of a non-adhesive, elastic material 32 consist of what 7 it can be seen that an arrangement 20 according to a second embodiment of the invention, wherein identical or similar features to the first embodiment are denoted by the same reference numerals as in the first embodiment. Further, the carrier 2 from a back protection body 33 covered, with the two protective bodies 12 and 33 by mechanical fasteners 34 , here in the form of screws, are firmly connected. Furthermore, between the back protection body 33 and the carrier 2 an elastic layer 41 arranged. According to 7 becomes for the intermediate layer 24 and / or for the elastic layer 41 preferably rubber used. The order 20 according to 7 forms in particular an electrical device according to a second embodiment of the invention.

For further description of the second embodiment, reference is made to the description of the first embodiment. In particular, the arrangement 20 according to the second embodiment, the arrangement 20 replace according to the first embodiment.

With reference to the 8th to 10 A third embodiment of the invention will be described, wherein to the previous embodiments, similar or identical features with the same reference numerals as in the previous embodiments are designated. According to 8th gets into a housing 25 a mask 35 used, which is an approximate positive shape of an assembly 1 forms according to 1 is constructed and a carrier 2 and having attached thereto components. The mask 35 is made by mechanical fasteners 40 , here in the form of screws, in the housing 25 forming at least one gap 36 fixed, the housing 25 at the same time forms a mold. Subsequently, the housing 25 with a liquid potting compound 31 poured out, what made 9 is apparent. This is the gap 36 between the mask 35 and the walls of the housing 25 with the potting compound 31 filled, being as potting compound 31 Polyurethane or epoxy resin can be used. After curing of the potting compound 31 becomes the mask 35 removed, passing through the cured potting compound 31 educated body 12 a negative mold of the mask and thus an approximate negative form of the assembly 1 forms. Subsequently, an elastic, adhesive intermediate layer 24 on the body 12 applied, after which the carrier 2 with the components on the body 12 is placed, thus forming a protective body. The body 12 , the case 25 and the assembly 1 thus form a coherent, especially monolithic structure. This is off 10 It can be seen that an electrical device 38 according to a third embodiment of the invention. For further description of the third embodiment, reference is made to the description of the first embodiment.

To prevent water or water vapor from entering the cavities between the carrier 2 and the protective body 12 occurs, connecting the assembly 1 with the protective body 12 in all embodiments, preferably in an inert atmosphere.

LIST OF REFERENCE NUMBERS

1

module

2

Carrier / circuit board

3

transformer

4

Connectors

5

Electrolytic capacitor

6

Diode with glass housing

7

SMD card

8th

transistor arrangement

9

Louvre

10

free space

11

Surface of the transistor arrangement

12

protective body

13

distance

14

distance

15

Deepening in protective body

16

Deepening in protective body

17

Deepening in protective body

18

Deepening in protective body

19

Deepening in protective body

20

arrangement

21

room

22

room

23

room

24

interlayer

25

casing

26

Fasteners / screws

27

Projection of the housing

28

through opening

29

adhesive

30

Distance / gap

31

potting compound

32

non-adhesive, elastic material / rubber

33

back protection body

34

Fasteners / screws

35

mask

36

Space between mask and housing

37

distance

38

electrical device

39

spacer

40

Fasteners / screws

41

Elastic layer

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 6583355 B2 [0006]
• DE 4224122 A1 [0008]
• US 6035524 [0010]

Claims (19)

Electric device with - a carrier ( 2 ) and electrical components ( 3 - 8th ) having assembly ( 1 ), the components ( 3 - 8th ) at predetermined positions on the carrier ( 2 ) and protrude from this, - one with the assembly ( 1 ), to this one distance ( 13 ), the components ( 3 - 8th ) and with depressions ( 15 - 19 ) provided protective body ( 12 ), the depressions ( 15 - 19 ) are arranged opposite to the predetermined positions, so that the components ( 3 - 8th ) into the depressions ( 15 - 20 ), - one in the distance ( 13 ) between the protective body ( 12 ) and the assembly ( 1 ) and both with the protective body ( 12 ) as well as with the assembly ( 1 ) in contact, elastic intermediate layer ( 24 ), characterized in that the intermediate layer ( 24 ) as a spacer between the assembly ( 1 ) and the protective body ( 12 ), so that a direct contact of the carrier ( 2 ) and protective body ( 12 ), the intermediate layer ( 24 ) at least in part the distance between the protective body ( 12 ) and the carrier ( 2 ) and both with the protective body ( 12 ) as well as with the carrier ( 2 ) is in contact. Electrical device according to claim 1, characterized in that the components ( 3 - 8th ) spaced apart on the support ( 2 ) are arranged. Electrical device according to claim 1 or 2, characterized in that a carrier ( 2 ) and with the depressions ( 3 - 8th ) provided front side of the protective body ( 12 ) one by the wearer ( 2 ) and the components ( 3 - 8th ) follows or at least approximately follows. Electrical device according to one of the preceding claims, characterized in that the recesses have dimensions such that the components ( 3 - 8th ) to the protective body ( 12 ) a circumferential distance ( 14 ) exhibit. Electrical device according to claim 4, characterized in that the circumferential distance ( 14 ) between one of the components ( 3 ) and the protective body ( 12 ) different from the circumferential distance ( 23 ) between another of the components ( 8th ) and the protective body ( 12 ). Electrical device according to one of the preceding claims, characterized in that the intermediate layer ( 24 ) the distance ( 13 ) between the assembly ( 1 ) and the protective body ( 12 ) at least partially and in contact with the institution ( 2 ), the protective body ( 12 ) and at least one of the components ( 3 ) stands. Electrical device according to claim 6, characterized in that the at least one with the intermediate layer ( 24 ) in contact by the intermediate layer ( 24 ) is centered and secured. Electrical device according to one of the preceding claims, characterized in that at least one of the depressions ( 19 ) free or substantially free of the intermediate layer ( 24 ). Electrical device according to one of the preceding claims, characterized in that at least one of the components ( 8th ) not with the intermediate layer ( 24 ) is in contact. Electrical device according to one of the preceding claims, characterized in that the components ( 3 - 8th ) by the carrier ( 2 ), the protective body ( 12 ) and the intermediate layer ( 24 ) are encapsulated and sealed to the outside. Electrical device according to one of the preceding claims, characterized in that the protective body ( 12 ) by at least one mechanical fastening means ( 34 ) on the carrier ( 2 ) is attached. Electrical device according to one of the preceding claims, characterized in that the protective body ( 12 ) by means of the intermediate layer ( 24 ) with the carrier ( 2 ) is glued. Electrical device according to one of the preceding claims, characterized in that the intermediate layer ( 24 ) is formed by an elastomer. Electrical device according to one of the preceding claims, characterized in that the bottom of at least one of the depressions ( 19 ) in heat-conducting contact with the arranged in this component ( 8th ) stands. Electrical device according to one of the preceding claims, characterized in that the device ( 1 ) and the Protective body ( 12 ) formed arrangement ( 20 ) at least partially from a casing ( 31 ) is surrounded. Electrical device according to one of the preceding claims, characterized in that the device ( 1 ) and the protective body ( 12 ) formed arrangement ( 20 ) into a container ( 25 ) is introduced. Electrical device according to claim 16, characterized in that the protective body extends into one of the recesses ( 19 ) opening, through opening ( 28 ) into which a projection ( 27 ) of the container ( 25 ), which in heat-conducting contact with the in this recess ( 19 ) arranged component ( 8th ) stands. Electrical device according to claim 15 and according to claim 16 or 17, characterized in that the arrangement ( 20 ) at least in regions spaced from the walls of the container ( 25 ) and the sheath ( 31 ) between the arrangement ( 20 ) and the walls of the container ( 25 ) is provided. Electrical device according to one of the preceding claims, characterized in that the intermediate layer ( 24 ) is electrically insulating and the carrier ( 2 ) by means of the intermediate layer ( 24 ) electrically from the protective body ( 12 ) is isolated.

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