WO2012146544A1

WO2012146544A1 - Electrical arrangement having a coating and gear arrangement having such an arrangement

Info

Publication number: WO2012146544A1
Application number: PCT/EP2012/057299
Authority: WO
Inventors: Andreas Otto; Sabrina RATHGEBER; Marc Fischer; Andreas Fix
Original assignee: Robert Bosch Gmbh
Priority date: 2011-04-26
Filing date: 2012-04-20
Publication date: 2012-11-01
Also published as: EP2702843A1; DE102011017521A1

Abstract

The invention relates to an electrical arrangement (1) containing a support (2) and at least one electrical component (3), which arrangement can be arranged at a location having aggressive substances and high temperatures and fluctuations in temperature. According to the invention, the electrical arrangement is provided with a coating (4), which consists of a curing component and ceramic particles and/or nanoparticles with oleophobic functional groups and further constituents where necessary. Hence, the wetting angle of the coating is increased and an attack by substances contained in the lubricant is effectively prevented. An electrical arrangement, which can be arranged without a protective housing for example in a gear arrangement for an automotive drive gear system, is thus provided.

Description

Description title

Electrical arrangement with coating and gear arrangement with such an arrangement

State of the art

The present invention relates to an electrical arrangement, in particular for positioning in a gear arrangement. More particularly, the present invention relates to an electrical assembly that includes electrical components to be warmed up and may come into contact with lubricious, aggressive substances.

State of the art

Electrical arrangements, such as control units for automotive applications, are often positioned in locations where they are significantly strained by operating conditions and environmental conditions. Since the electrical control devices are usually arranged in the vehicle near or even on the respective unit of the vehicle, come to the environmental influences, such as moisture and aggressive substances, in addition

Vibrations and high temperatures as well as high temperature change ranges. In addition, the electrical arrangements often produce even a considerable amount of electrical waste heat. To protect against environmental influences, therefore, various possibilities are known in the prior art, electrical

Protect components against environmental influences. DE 20 2005 009 039 U 1 shows an electrical control device for a transmission control arranged in a housing. To protect against electronic heat is also a

Electronic heat protection barrier provided in the housing. The aforementioned solutions have in common that the measures for the protection of the electronic control unit bring a considerable constructive and manufacturing-related and material costs. In particular, for the mass production generally used in the automotive industry, such an arrangement is disadvantageous and economically undesirable.

In addition, a separate housing with appropriate space requirements, both in the vehicle itself and in storage, connected. Moreover, previous protective lacquers, as well as heat-dissipating cases, have often been detrimental. In view of the fact that in the event of a defect in an electronic control unit, the unit is only rarely repaired, but much more often completely replaced, is also for the maintenance and repair in workshops a cost-effective design and simple

Accessibility of electrical control devices advantageous. Disclosure of the invention

The electrical arrangement according to the invention with the features of claim 1 has the advantage over the known concepts for encapsulating an electrical arrangement against aggressive substances and other environmental influences that can be dispensed with a housing entirely. Nevertheless, a reliable protection of the electrical arrangement against aggressive

Substances, e.g. Sulfur, given, which lead on the one hand to corrosion, so a removal, for example of traces on a support, on the other hand, for the deposition of metallic substances between the electrical conductors on a support and thus could form short circuits.

In particular, in gearboxes also generated by abrasion metal chips for the function of the electrical components located in the transmission oil can be dangerous. Again, the coating of the invention provides effective remedy. If the electrical arrangement has components to be warmed up, the coating of the arrangement according to the invention moreover ensures that sufficient heat dissipation to the surroundings is ensured. The carrier of the electrical arrangement according to the invention may be, for example, an organic circuit carrier, a printed circuit board or a circuit board, on which as electrical components Wderstände, transistors, capacitors and integrated circuits and entire processors and memory modules can be arranged. The cured component of the coating can for example, a resin or a paint, in particular a printed circuit board protective lacquer. According to the invention, the coating comprises ceramic particles, which may comprise, for example, MgO, Al ₂ O ₃ , BN, AIN. In addition, fluorine groups, for example, are typically suitable as oil-repellent functional groups in the nanoparticles. Such a defined coating has the advantage over prior art coatings that on the one hand an attack by the arrangement surrounding chemically aggressive substances due to the oil-repellent particles is effectively repelled, on the other hand, the heat dissipation via an admixture of ceramic particles

is guaranteed

The dependent claims show preferred developments of the invention.

Preferably, the coating can be provided both on the carrier and on the electrical components. In order to wet both the surfaces of the electrical components and the surface of the carrier at least approximately completely with the coating, the coating may preferably be applied to the electrical arrangement in a dipping process and / or in a spraying process. The surface structure of the ceramic particles causes an oil-repellent outer surface of the coating.

In addition, it is possible to thermally conductive particles, in particular

Ceramic particles to provide in the coating before applying to the electrical arrangement, whereby the coating is interspersed by these thermally conductive particles to a high thermal

Conductivity of the coating to achieve. In addition, it may be particularly advantageous to provide those particles which are intended for the oil-repellent function (for example ceramic particles and / or nanoparticles with fluorine groups) only on the outside of the coating in order to prevent ingress of oil or aggressive substances. In particular, therefore, the oil-repellent character of the coating by a subsequent

Apply appropriate nanoparticles on the applied coating, for example, during curing of the coating and / or by a subsequent vapor deposition after curing of the coating may be provided. The coating may preferably contain ceramic particles and / or nanoparticles for cooling the electrical arrangement. Alternatively, second ceramic particles and / or nanoparticles for cooling the electrical

Arrangement be included. In particular, the resulting in processors electrical heat is thus effectively on the coating from the electrical

Arrangement dissipated. Particular preference is given to the cooling

exclusively by the ceramic particles.

More preferably, the ceramic particles comprise MgO and / or Al ₂ O ₃ and / or BN and / or AlN. While the above-mentioned substances have been found to be advantageous for the function according to the invention, the particles which are suitable for an oil-repellent and heat-dissipating function are not limited to these substances. Fullerenes and / or fluorohydrocarbons are preferably used as nanoparticles with an oil-repellent function.

Advantageously, the ceramic particles have a proportion of 10 to 50% by volume, preferably 25 to 35% by volume, of the cured coating. The

The above-mentioned proportions of the ceramic particles on the cured coating, wherein also further second ceramic particles are included, have proven to be particularly advantageous for the fulfillment of the oil-repellent and heat-dissipating

Function of the coating exposed.

The nanoparticles in the coating preferably have a fraction of from 10 to 50% by volume, preferably from 25 to 35% by volume, of the cured material

Coating, wherein also further second nanoparticles are included here. The abovementioned percentages have proven to be particularly advantageous in the production of an oil-repellent surface of the coating.

According to another aspect of the present invention is a

Transmission arrangement provided, which is a transmission, a

Lubricant and at least one electrical arrangement, as has been previously described. The transmission can, for example, a

Be drive gear for an automobile. On the transmission can a

Transmission control unit as an electrical arrangement according to the present

Be arranged invention. As the electrical arrangement against the corrosive

Substances in the lubricant and the prevailing at the transmission high Temperatures and temperature change is protected over a wide range, the electrical arrangement can even be placed in the lubricant of the transmission or at least in an area closed by the oil pan area, where it is particularly well protected against mechanical effects such as shocks and vibrations. Since the electrical arrangement according to the invention does not have a separate housing, its volume is particularly low and the degrees of freedom for a positioning as well as the so-called "package" are particularly large, more preferably the gear arrangement comprises an oil sump, the electrical arrangement without a protective housing in the sump

closed volume of the gear assembly is arranged. The electrical arrangement according to the present invention, neither the chemically aggressive substances nor the high temperatures and the temperature changes can be something, so that in the oil sump

closed volume is particularly well protected against further environmental influences and in particular against mechanical shocks and vibrations.

According to another aspect of the present invention, there is provided a method of manufacturing an electrical device as described above. According to this aspect, the method comprises the following steps: equipping a carrier, in particular a printed circuit board, with electrical components. In particular, a board with exposed conductor tracks, for example made of copper, comes into question as the carrier. For electrical insulation, the printed circuit board can be coated, for example, after the first assembly with a conventional paint as a primer for electrical insulation and adhesion. Subsequently, a coating composition of a curable substance by admixing ceramic particles and / or nanoparticles with oil-repellent, functional groups, in particular fluorine groups prepared. The curable substance may, for example, a resin, a Lackart and a

Printed circuit board protection paint. In particular, in this step, those constituents or particles are admixed which ensure a high thermal conductivity of the coating. As a final step, the coating composition is applied to the stocked carrier, in particular by dipping and / or spraying. Optionally, in addition, a suitable Concentration of nanoparticles on the surface of the applied

Coating can be applied. Thus, the coating receives on the one hand a high thermal conductivity by penetration of thermally conductive particles, on the other hand on the outside a strong oil repellency.

According to an alternative embodiment of the method according to the invention, the method comprises the steps: equipping a carrier, in particular a printed circuit board, with electrical components, applying a curable substance to the loaded carrier, in particular by dipping and / or spraying, and then applying ceramic particles and / or Nanoparticles with oil-repellent, functional groups, in particular

Fluorine groups, on the uncured substance on the stocked carrier. The above-described method offers the advantage that a particularly homogeneous layer envelops the electrical arrangement and thus protects it against oil and aggressive substances. The oil-repellent surface receives the

Coating according to this embodiment of the manufacturing process only after the process of applying the curable substance. Even while the coating on the carrier or the electrical

Curing components, the ceramic particles and / or nano-particles are applied, whereby they penetrate only into outer regions of the coating. With increasing distance from the carrier or the electrical components thus results in an increasing concentration of particles through the coating in the direction of the surface.

drawings

Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawings show:

1 shows a sectional view through an inventive electrical

Arrangement;

Figure 2 is a partially sectioned side view of a

transmission arrangement according to the invention; and Figure 3 ac steps of the manufacturing method according to the invention for an electrical arrangement according to the invention.

Preferred embodiments of the invention

The essential features of an electrical arrangement 1 according to a first exemplary embodiment of the present invention will be explained below with reference to FIG. In Figure 1, a printed circuit board carries as a carrier 2 both on its underside and on its top electrical components 3. These electrical components 3 are shown only schematically and may include, for example, resistors, capacitors, transistors, integrated circuits and memory devices and processors. Two of the electrical components 3 are arranged as components to be warmed 3a on the upper side of the circuit board. A coating 4 surrounds the electrical components 3 and 3a, as well as the carrier 2. Within the

Coating 4, ceramic particles are provided as particles 4a and illustrated as dots.

FIG. 2 shows a gear arrangement 6 according to the invention. In the lower area of the gear arrangement 6 there is an oil pan 7 in which transmission oil 5 is located. In the completed by the oil pan 7 volume is an electrical arrangement 1 according to the present invention.

In conjunction with FIGS. 3 a to 3 c, an embodiment of a method according to the invention for producing an electrical arrangement 1 according to the present invention is shown.

In FIG. 3 a, a printed circuit board as a carrier 2 is equipped with an electrical component 3 and an electrical component 3 a to be devoured.

In FIG. 3b, the printed circuit board is provided with a printed circuit board protective lacquer as a curable substance for forming a coating 4. The printed circuit board protective lacquer is applied to the carrier 2 and the electrical components 3 and 3a, for example, by a dipping method or a spraying method. The lacquer may consist only of the curable substance itself, or may already contain ceramic and / or nanoparticles as particles 4a. FIG. 3c shows the electrical arrangement 1 which is completely surrounded by the printed circuit board protective lacquer 1. In order to make the outer surface of the coating 4 particularly oil-repellent, nanoparticles are deposited on the surface of the particles 4a as particles

Coating 4 applied. This can, for example, in a scatter or

Aufdampfvorgang happen. In this case, a large part of the nanoparticles remain on the surface of the coating 4 or penetrate at least only a little into the coating 4.

The foregoing embodiments merely illustrate aspects of the present invention and do not limit the scope of protection as defined by the appended claims.

The central idea of the present invention is to provide an electrical arrangement comprising a carrier and at least one electrical component, which can be arranged at a location having aggressive substances as well as high temperatures and temperature changes. According to the present invention, the electrical arrangement is provided with a coating which consists of a curing component and ceramic particles and / or nanoparticles with oil-repellent functional groups and

optionally further constituents. This will be the

Increased wetting angle of the coating and thus effectively prevented attack by substances contained in the lubricant. Thus, an electrical arrangement is provided which can be arranged without a protective housing, for example in a transmission arrangement for an automotive drive transmission.

Claims

Electrical arrangement, in particular for positioning in a

Gear arrangement (6), comprising:

a carrier (2), and

at least one electrical component (3) arranged on the carrier (2),

wherein the electrical assembly (1) comprises a coating (4) comprising a cured component and a portion of

Ceramic particles and / or nanoparticles, wherein the

Ceramic particles and / or nanoparticles oil-repellent, functional groups, in particular fluorine groups have.

Electrical arrangement according to claim 1, wherein the coating (4) on the support (2) and on the electrical components (3) and in particular in a dipping process and / or in a

Spray method has been applied and preferably the carrier (2) and the at least one electrical component (3) are at least approximately completely enclosed by the coating (4).

Electrical arrangement according to claim 1 or 2,

wherein the ceramic particles and / or nanoparticles of the coating (4) for the cooling of the electrical arrangement (1 are set up, or

second ceramic particles and / or second nanoparticles for cooling the electrical arrangement (1) in the coating (4) are provided.

Electrical arrangement according to one of the preceding claims, wherein the ceramic particles comprise MgO and / or Al ₂ 0 ₃ and / or BN and / or AIN.

Electrical arrangement according to one of the preceding claims, wherein the ceramic particles in the coating (4) have a proportion of the cured coating (4) of 10 to 50 vol .-%, preferably 25 to 35 vol .-%. Electrical arrangement according to one of the preceding claims, wherein the nanoparticles in the coating (4) have a proportion of the cured coating (4) of 10 to 50 vol .-%, preferably 25 to 35 vol .-%.

Transmission arrangement comprising a gear, a lubricant and at least one electrical arrangement (1) according to one of the preceding claims.

Transmission assembly according to claim 7, wherein the gear assembly (6) further comprises an oil pan (7) and wherein the electrical assembly (1) without a protective housing in a lubricant and high

Temperatures exposed area of the gear assembly (6), in particular in of the oil pan (7) completed volume is arranged.

Method for producing an electrical arrangement (1) according to one of Claims 1 to 6, comprising the steps:

Equipping a carrier (2), in particular a printed circuit board, with electrical components (3),

Creating a mixture by admixing ceramic particles and / or nanoparticles with oil-repellent, functional groups, in particular fluorine groups, to a curable substance, and applying the mixture to the stocked carrier (2), in particular by dipping and / or spraying.

Applying a curable substance, in particular a paint or resin, on the stocked carrier (2), in particular by dipping and / or spraying, and

Application of ceramic particles and / or nanoparticles with oil-repellent, functional groups, in particular fluorine groups, on the uncured substance on the equipped carrier (2).