WO2013110416A1

WO2013110416A1 - Gearbox control module with oil-resistant conductor paths

Info

Publication number: WO2013110416A1
Application number: PCT/EP2012/075949
Authority: WO
Inventors: Andreas Otto; Sabrina RATHGEBER; Marc Fischer
Original assignee: Robert Bosch Gmbh
Priority date: 2012-01-24
Filing date: 2012-12-18
Publication date: 2013-08-01
Also published as: DE102012201014A1; EP2807405A1; KR20140124363A; CN104067030A; CN104067030B

Abstract

The invention relates to a gearbox control unit (1) for a motor vehicle. Electrical components (7, 9, 11) are used for implementing a gearbox control function and are interconnected by means of conductor paths (5). According to the invention, the conductor paths (5) are made substantially of an electrically conductive material other than copper. By replacing conductor paths containing copper with different electrically conductive conductor paths, such as those made of an electrically conductive plastic or from nickel, gold, tin, silver or palladium, contact with chemically aggressive gearbox oil, for example, that corrodes the conductor paths, and a subsequent malfunction of the gearbox control unit, is prevented.

Description

description

Transmission control module with oil-resistant conductor tracks The present invention relates to a transmission control module for a motor vehicle. Furthermore, the invention relates to the use of a printed circuit board in a motor vehicle.

PRIOR ART In modern motor vehicles electrical circuits are used in a variety of ways, for example for controlling vehicle components, such as vehicle components. an automatic transmission. In such electrical circuits, electrical components such as resistors, diodes, transistors, ICs, etc. are interconnected. For interconnection of the components, conductor tracks are usually used, which electrically connect the components to one another. The components can be arranged on a circuit carrier such as a printed circuit board, wherein the conductor tracks are part of the circuit substrate.

For example, in modern motor vehicles for controlling

Transmission functions Transmission control modules used. These transmission control modules can preferably be accommodated directly in a housing of the transmission. In doing so, the transmission control module usually comes in contact with the aggressive fluids contained in the transmission, such as e.g. Transmission fluid. DE 10 2009 00 427 AI shows a transmission control module in which a circuit carrier is protected by means of a media-resistant enclosure against aggressive fluids.

DISCLOSURE OF THE INVENTION The present invention, in its embodiments, makes it possible to provide a transmission control module, which advantageously directly into a motor vehicle transmission can be integrated and are exposed to the tracks no degradation by aggressive fluids. In other embodiments, the present invention allows a use of a printed circuit board in a motor vehicle, in particular in a motor vehicle transmission, wherein printed conductors of the printed circuit board are not subject to degradation by aggressive fluids.

According to one embodiment of the present invention is a

Transmission control module proposed in which electrical components for implementing a transmission control function are electrically interconnected. The electrical interconnection is carried out by means of conductor tracks, which are provided on a printed circuit board. The conductor tracks consist essentially of a different electrically conductive material than copper.

According to another embodiment of the present invention, the

Use of a printed circuit board proposed in a motor vehicle, wherein the

Printed circuit board has conductor tracks for electrical interconnection of electrical components and the conductor paths consist essentially of a different electrically conductive material than copper. An idea or realization on which the embodiments of the invention are based can be seen in that it has been found that in particular the aggressive fluids used in vehicle transmissions, such as transmission oil, for example, the tracks used conventionally on a circuit carrier

Essentially consist of copper, attack with time. For example, it has been observed that over the life of a vehicle transmission, for example, up to 20 years, the transmission oil is in contact with the transmission oil

Can strongly corrode conductor tracks. In particular, additives of the gear oil such as sulfur, but also the base oil itself, can react with the copper of the tracks, whereby this can go into solution. As a result, it can lead to interruptions of the tracks, which can eventually lead to malfunction or even failure of the transmission control module.

Based on this finding, in particular for the case that a holder of the transmission control module is formed and the circuit board in the

Transmission control module is arranged such that the transmission control module can be integrated in a vehicle transmission such that the interconnects with a Gear fluid come into contact, proposed that the interconnects consist essentially of a different electrically conductive material than copper. In other words, the interconnects should essentially not contain any copper, ie be low in copper or preferably copper-free. In this context, "essentially" can be understood to mean that the interconnects contain as much copper as possible so that the interconnects remain functional even if the copper portion is completely removed

Functionality to be achieved for the particular application

Current carrying capacity should be considered.

Since in the interconnects on the sensitive, for example, gear oil copper is omitted, the circuit board including the components and conductors can be used, for example, in the harsh conditions of a vehicle transmission, without areas of the circuit board or the interconnects, for example, by a cover or encapsulation would need to be protected from contact with aggressive fluid from the transmission. For example, the circuit board can be designed as a simple or multilayer printed circuit board and thus the entire transmission control module as simple and inexpensive to produce electrical

Circuit can be formed using the large-scale industrially manageable circuit board technology. Only the printed conductors of such a printed circuit board are formed here with other materials instead of the conventionally used copper in order to form a printed circuit board with sufficient current carrying capacity

To transmit signal streams to provide. For example, the conductor tracks can be formed with an electrically conductive plastic and preferably consist predominantly of an electrically conductive plastic.

By "predominantly" is to be understood in this context that at least 50 vol% of a conductor made of an electrically conductive plastic and preferably a proportion of other materials such as copper in particular is so low that a loss of these materials or the copper, for example Corrosion does not lead to a significant impairment of the function of the circuit board. As electrically conductive plastics, for example, highly filled plastics can be used, wherein the filler can usually consist of nickel or silver and the plastic can be Epoxydharzsysteme or silicones. Alternatively, tinned copper flakes can be used as filler. As a matrix for the filler can continue to serve thermoplastics such as polyamide. Such electrically conductive plastics can have a high chemical resistance and high adhesive forces. The electrically conductive plastic can in this case have a specific electrical conductivity of at least 10.sup.- ⁴ .OMEGA.cm.Alternatively, the conductor tracks may consist predominantly of a metal or a metal

Combination of metals, wherein the metal or metals should be resistant to gear oil. By way of example, the conductor tracks may be formed predominantly of nickel, gold, tin, silver and / or palladium. Due to their very high electrical conductivity, silver and gold can be of interest in particular for applications requiring a high current carrying capacity. Although nickel and tin have a lower conductivity, but are clear

cost-effective.

In one embodiment, the transmission control module may include a printed circuit board having a plurality of tracks running in different planes. Such multilayer printed circuit boards enable complex interconnection structures between electrical components, wherein interconnects that run in different planes can also cross in plan view, without causing short circuits. In the proposed transmission control module, such multi-layered

Printed circuit boards in particular be designed such that at least outer conductor tracks of the multilayer printed circuit board substantially consist of a different material than copper. The outer conductor tracks, which come into contact with aggressive fluids during use in the motor vehicle transmission, are therefore not subject to degradation due to a chemical attack of copper contained in the conductor tracks. The internal conductor tracks of the printed circuit board, which do not directly come into contact with the aggressive fluids, can be conventional conductor tracks made of copper or, like the outer conductor tracks, also essentially copper-free. In embodiments, the present invention provides the ability to work in the

Substantial PCB technology for implementing a transmission control module and its use in aggressive fluids such as oils of a gearbox. In this case, no coverage or encapsulation of the tracks is needed. A cost-effective alternative to gearbox controls based on stamped bars is offered. Furthermore, a low-cost technology for small batches is made possible. As a result, a shortening of development times, in particular, for example, in the production of patterns, and a saving of tooling costs can be made possible.

It is noted that possible features and advantages of embodiments of the invention are described herein in part with reference to a transmission control module and in part with respect to the use of a printed circuit board in a motor vehicle. A person skilled in the art will recognize that the individual features can advantageously be combined or exchanged with one another in order to be further

Embodiments and in particular to achieve possible synergy effects.

It should also be noted that the term "transmission control module" is to be interpreted broadly and is intended to include in particular all electrical circuits which are integrated in one

Motor vehicle for controlling a transmission, in particular an automatic transmission, are used, such. Sensor modules, actuator modules, monitoring modules, control modules, control modules, etc.

Brief description of the drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, in which neither the description nor the drawings are to be construed as limiting the invention. FIG. 1 shows a plan view of a transmission control module according to FIG

Embodiment of the present invention;

Figure 2 shows a sectional view of a multilayer printed circuit board for a

Transmission control module according to an embodiment of the present invention. The figures are only schematic and not to scale.

DETAILED DESCRIPTION FIG. 1 shows a very schematically illustrated transmission control module 1, which is designed to control an automatic transmission of a motor vehicle. On a circuit board 3, a plurality of electrical components 7, 9, 11 are provided, the one

Implement transmission control function. The electrical components 7, 9, 11 are electrically interconnected by interconnects 5. For electrical contact with other devices within the motor vehicle connections 13 are provided. As a simple embodiment of a holder 17 3 openings are provided at the corners of the circuit board to which the circuit board 3 can be screwed for example inside a gear housing. The printed circuit board 3 or board or printed circuit (English: Printed Circuit

Board, PCB) serves as a carrier both for mechanical attachment of the components 7, 9, 11 as well as for their electrical connection by means of the conductor tracks 5. According to conventional printed circuit board technology, the printed circuit board of an electrically insulating material having adhered thereto conductive connections to form the conductor tracks be designed. As insulating material, for example, fiber-reinforced plastic can be used. The components 7, 9, 11 are

typically on solder pads, so-called pads, or pads by

However, solder joints held, but can also be mechanically attached to the circuit board in other ways and electrically connected to this. For example, electrically conductive adhesives can be used.

The interconnects 5 have electrically conductive material, but in the

Substantially dispensed with copper as a conductive material. Instead, the tracks 5 may be e.g. made of electrically conductive plastic or other

Metals such as e.g. Nickel, gold, tin, silver or palladium or combinations of such metals.

FIG. 2 shows a cross section of a printed circuit board 3 in the form of a multilayer printed circuit board. In a stack 55, in which several boards are stacked one above the other, printed conductors 51, 52, 53 are formed in different levels. Outside of the stack 55 are outer conductor tracks 5 and exposed to the outside Contacts 13 are provided. The stack 55 is wrapped by insulating material 15 such as a solder resist. At least the outer conductor tracks 5 consist of a copper-poor or copper-free material.

Claims

claims

1 . Transmission control module (1) for a motor vehicle, comprising:

electrical components (7, 9, 11) for implementing a transmission controfunction; and a printed circuit board (3) with conductor tracks (5) for the electrical connection of the electrical components (7, 9, 11);

characterized in that

the conductor tracks (5) consist essentially of a different electrically conductive material than copper.

2. Transmission control module according to claim 1, wherein a holder (17) of the

Transmission control module (1) is formed and the circuit board (3) in the

Transmission control module (1) is arranged such that the transmission control module (1) is to be integrated in a vehicle transmission such that the conductor tracks (5) come into contact with a transmission fluid.

3. Transmission control module according to claim 1 or 2, wherein the conductor tracks (5) consist predominantly of an electrically conductive plastic.

4. Transmission control module according to one of claims 1 to 3, wherein the conductor tracks (5) consist predominantly of a metal which is resistant to gear oil.

5. Transmission control module according to one of claims 1 to 4, wherein the conductor tracks (5) consist predominantly of a metal selected from the group comprising nickel, gold, tin, silver, and palladium.

6. Transmission control module according to one of claims 1 to 5, wherein the circuit board (3) a plurality of conductor tracks (5) which extend in different planes.

7. Transmission control module according to claim 7, wherein at least external

Conductor tracks (5) consist essentially of a material other than copper.

8. Use of a printed circuit board (3) in a motor vehicle, wherein the printed circuit board (3) conductor tracks (5) for electrical interconnection of electrical components (7, 9, 1 1) and wherein the conductor tracks (5) come into contact with a chemically aggressive fluid;

characterized in that