WO2017054981A1

WO2017054981A1 - Electronic module for a transmission controller

Info

Publication number: WO2017054981A1
Application number: PCT/EP2016/069343
Authority: WO
Inventors: Uwe Liskow
Original assignee: Robert Bosch Gmbh
Priority date: 2015-10-02
Filing date: 2016-08-15
Publication date: 2017-04-06
Also published as: DE102015219072A1

Abstract

The invention relates to an electronic module (10) for a transmission controller of a motor vehicle, having a printed circuit board (12) with an electronic circuit (18), a conductor foil (20), and a base plate (30). The printed circuit board (12) has an assembly surface (14) on which the electronic circuit (18) is arranged and a contact surface (16) opposite the assembly surface (14). The assembly surface (14) is at least partly covered with a protective compound (28), and the contact surface (16) of the printed circuit board (12) is arranged on the base plate (30). The electronic module (10) is characterized in particular in that at least one sub-region (21) of the conductor foil (20) is arranged between the base plate (30) and the contact surface (16) of the printed circuit board (12), and a plurality of contact points (15) are formed on the contact surface (16) of the printed circuit board (12), each contact point being connected to a conductor path (26) of the conductor foil (20) in an electrically conductive manner. Thus, a robust, reliable, and inexpensively producible electronic module (10) is provided.

Description

description

Electronic module for a Getriebesteuerqerät area of the invention

The invention generally relates to an electronic module. In particular, the invention relates to an electronic module for a transmission control unit of a motor vehicle.

State of the art

For controlling transmissions, in particular automatic transmissions, in a motor vehicle electronic modules are used, which are usually a transmission control unit with an electronic circuit ("transmission control unit", TCU), at least one connector for connection to a

Vehicle wiring harness, electrical interfaces for driving actuators and at least one sensor element.

The sensor elements can be designed in particular for determining a rotational speed and / or for determining paths or positions in the transmission. For example, such sensor elements as

Hall sensors, such as in the form of an integrated circuit (or an "Integrated Circuits", IC) or in the form of an application-specific integrated circuit (or "Application-Specific Integrated Circuit", ASIC).

Especially when used in a transmission of a motor vehicle

Electronic modules, also called integrated transmission control modules, it may be necessary to protect the electronic components of the electronic module from the sometimes aggressive media, such as a transmission fluid, comprehensive and durable. For this purpose, the electronic components are often encapsulated in a protective compound or coated with a protective varnish and / or protected with a lid. The electronic circuit can also be contacted, for example, with a module printed circuit board, a flexible printed circuit board and / or a stamped grid and connected to other components. From DE 10 2010 039 187 A1 an electrical connection arrangement is known, in which an electronic module has a contact plate, which is contacted with a flexible flat conductor or a flexible conductor foil. The flat cable is between the contact plate and a Gehäusevorspung the connection assembly largely powerless plugged in and through

Forming the contact plate is an electrically conductive connection to produce.

Disclosure of the Invention Advantages of the Invention

Embodiments of the present invention may advantageously enable a robust, reliable, and economically producible electronic module for a transmission control unit of a motor vehicle

provide.

According to one aspect of the invention, an electronic module for a

Gearbox control unit of a motor vehicle proposed which a

Printed circuit board having an electronic circuit, a conductor foil with recorded between a base layer and a cover layer traces for electrically contacting the electronic circuit and a base plate. The circuit board has a mounting surface on which the electronic circuit is arranged, and one of the mounting surface

opposite contact surface. The mounting surface is at least partially, in particular completely, with a protective compound to protect the electronic

Circuit covered against environmental influences, and the circuit board is arranged with the contact surface on the base plate. The electronic module is characterized in particular by the fact that at least a portion of the conductor foil between the base plate and the contact surface of the circuit board is arranged, and that on the contact surface of the circuit board, a plurality of contact points is formed, which for contacting the electronic circuit each with a conductor of the Conductive foil are electrically conductively connected. The mounting surface of the printed circuit board may be an upper side of the printed circuit board and the contact surface may denote a lower side of the printed circuit board. The conductor foil may in particular designate a flexible conductor foil, a flexible flat conductor and / or a "flexible printed circuit, FPC".

The electronic circuit can according to the invention on the opposite side of the electronic circuit or surface of the circuit board at the contact points of the printed circuit board with the portion of the conductor foil, which may for example denote a contact region of the conductor foil contacted or electrically conductively connected. The portion of the conductor foil can be accommodated between the base plate and the circuit board, so that advantageously the electrical contacts between the contact points and the tracks of the conductor foil against transmission fluid and / or caused by transmission fluid or chips in the transmission fluid short and

Shunts can be comprehensively protected (so-called chip protection).

Ideas for embodiments of the present invention may be considered, inter alia, as being based on the thoughts and findings described below. The e.g. With a further printed circuit board, a conductor foil and / or a punched grid contacted contact points of the electronic circuit are often arranged in known electronic modules in an edge region of the circuit board on the same side, on which also the

electronic circuit is arranged. On the one hand, the contact points are therefore only costly against influences of the transmission fluid, such as against short circuits and shunts, protectable and on the other hand space on the mounting surface of the circuit board is required for the contact points, which is then no longer available for the electronic circuit or It may therefore be necessary to use larger printed circuit boards. By the invention

Design of the electronic module can according to one for the

Components required area the entire mounting surface can be used for the electronic circuit and / or the circuit board can be made smaller overall.

Furthermore, especially when using glued and / or bonded bare-die components of the electronic circuit, the size of the printed circuit board, which may be, for example, a "high-density interconnect, HDI" printed circuit board, may be limited when mounted through a working area for fine wire bonders. which connect the bare-die devices to the circuit board. If, for example, an existing system for the processing of two-inch printed circuit boards is available for the assembly of the printed circuit board with the components and the associated bonding or wiring, the size of the printed circuit board is limited to two inches. By the present invention, the entire mounting surface of the circuit board for the

Components of the electronic circuit can be used and on the tightly mounted mounting surface is not necessarily an edge area for a connection or a further Kontakierung be kept to the outside, as these connections are on the bottom or the contact surface. This allows the circuit board or mounting surface to be encapsulated directly after loading, e.g. by casting the components or the

electronic circuit with the protective ground, which is about one

Epoxy resin composition and / or electronic potting compound may be. Also, the circuit board or the mounting surface can be protected directly after loading by gluing a lid. Overall, an assembly effort for mounting the components of the electronic circuit can be reduced by the larger surface available, which in turn can be associated with a cost savings. Also, the electronic module can be made compact overall.

The protection provided by the protective composition may further according to the invention extend to the edge of the circuit board and also include the edges of the circuit board (e.g., cut edges). Therefore, when using an HDI circuit board with bonded and / or bonded bare dies, the mounting surface does not need to be ground with e.g. Solder mask, tinning or another

Surface protection are treated. The topmost layer of the printed circuit board, which e.g. can be arranged directly under the protective ground, is usually led out in conventional electronic modules from the protective material, for example, to a contact pad at the edge of the mounting surface of the circuit board, which, for. bare copper or gold plated and / or can be nickel-plated.

Such can be omitted in the electronic module according to the invention, since the entire mounting surface can be covered with protective material. The contact points arranged on the contact surface can also be contacted or connected to the conductor foil prior to assembly of the printed circuit board on the baseplate, so that the contact points can be comprehensively protected.

Furthermore, by the arrangement of the portion of the conductor foil and the arrangement of the contact points between the contact surface and the base plate, such as mentioned above, the chip protection can be improved, whereby also about a use of a protective compound to protect the electrical contacts between the conductor foil and the contact points can be reduced. Furthermore, it is also possible to dispense with further contacting of the printed circuit board via contact plates, for example. Overall, according to the above, a compact, economically producible and robust electronic module can be provided.

According to one embodiment of the invention, a contact pad, which protrudes from the contact surface and which is electrically conductively connected to one of the conductor tracks of the conductor foil, is arranged on the contact points of the printed circuit board formed on the contact surface. As a result, secure and robust contact points can be provided, which can be contacted in a simple manner with the conductor tracks. According to one embodiment of the invention, the conductor foil in the portion arranged between the base plate and the contact surface of the printed circuit board on a plurality of recesses introduced into the base layer or the cover layer, wherein each one of the contact pads of the circuit board is received in one of the recesses of the conductor foil. The contact pads can partially and in particular completely in the

Recesses added. Thereby, the chip protection can be further improved because e.g. a creepage distance for shorts and shunts may be increased. According to one embodiment of the invention, electrical contacts of the electronic circuit are guided from the mounting surface through the printed circuit board to the arranged on the contact surface contact points of the printed circuit board. The electrical contacts can be performed, for example, via conductor tracks integrated in the printed circuit board from the mounting surface to the contact surface, which can thus be comprehensively protected against influences of the transmission fluid.

Overall, such exposed interconnects can be avoided, which would otherwise be additionally protected.

According to one embodiment of the invention, the conductor tracks of the

Conductor foil connected in each case via a solder depot with the contact points of the circuit board, and / or the conductor tracks of the conductor foil are soldered to the contact points of the circuit board, for example by means of ironing and / or light soldering. This can advantageously be a cost effective and reliable be made electrical connection between the conductors and the contact points.

According to one embodiment of the invention, the contact surface of

Printed circuit board attached by means of an adhesive bond to the base plate. To the

Forming the adhesive bond may be, for example, an adhesive and / or a e.g. epoxy resin-based potting compound can be used. As stated above, the electronic circuit can be encapsulated with protective compound prior to mounting the circuit board on the base plate. Therefore, the circuit board can also be fixed with a silicone-containing potting compound or a silicone-containing adhesive on the base plate. If the electronic circuit was potted with protective compound only after mounting the circuit board on the base plate, then no silicone-containing potting compound should be used for the adhesive bond, since during curing silicone outgassing could occur, which could chemically alter the surface finish of the circuit board so that the protective material is no longer sufficient could stick to the mounting surface. Thus, by using a low-cost silicone-containing standard material for the adhesive bond, the cost of the

Electronic module can be reduced.

According to one embodiment of the invention, a heat-conducting film and / or a heat-conducting adhesive for dissipating heat from the printed circuit board to the base plate is arranged between the base plate and the contact surface at least in a partial region.

The heat-conducting adhesive may also be silicone-containing for the reasons explained above and / or the heat-conducting adhesive may be used to produce the adhesive bond between the printed circuit board and the base plate. By using a heat conducting foil with a thermal conductivity of e.g. greater than or equal to about 3 W / mK can also heat conduction compared to a use of a thermal adhesive with about 1 W / mK be further increased and robustness and reliability of the electronic module can be further increased.

According to one embodiment of the invention, the heat-conducting film and / or the heat-conducting adhesive is enclosed on an outer periphery by an adhesive with which the printed circuit board and / or the contact surface of the printed circuit board is fastened to the base plate. Preferably, the heat-conducting film and / or the thermal adhesive is completely of the adhesive, which is about an adhesive and / or a Potting compound can be enclosed. For example, the heat-conducting foil and / or the heat-conducting adhesive can be arranged in a central region of the contact surface and enclosed on the outer periphery by the adhesive so that the heat-conducting foil and / or the heat-conducting adhesive need not be resistant to transmission fluid and / or must be further protected. The surrounding

Adhesive composition therefore does not have to be optimized with regard to thermal conductivity, since increased thermal conductivity is at the expense of resistance to heat

Transmission fluid can go. Thus, a cost-effective and reliable against transmission fluid resistant adhesive can be used, which can be cured, for example thermally, such as by heating the base plate.

According to one embodiment of the invention, a protective compound for protecting the contact points of the printed circuit board is arranged at least in a partial region of an outer circumference of the printed circuit board. Thus, the contact points and / or edges of the circuit board can be further protected against transmission fluid.

According to one embodiment of the invention, the conductor foil has a

Projection on which is arranged between the contact surface and the base plate, wherein arranged in the projection conductor track of the conductor foil is electrically conductively connected to a arranged in a central region of the contact surface pad of the circuit board. In other words, the contact points in the central region, approximately centrally located in the contact surface, and therefore need not be at the edge of the

Can be arranged contact surface, so that a flexibility in terms of a layout of the electronic circuit can be increased. For contacting these centrally arranged contact points, the conductor foil on the projection, wherein the heat-conducting film and / or the thermal adhesive accordingly

may be interrupted or may have cooperatively configured recesses.

Brief description of the drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, in which neither the drawings nor the description are to be construed as limiting the invention.

Fig. 1A shows an electronic module according to an embodiment of the invention. Fig. 1B shows a section through the electronic module of Fig. 1 A.

2 shows a detailed view of a part of an electronic module according to an embodiment of the invention.

The figures are only schematic and not to scale. Like reference numerals in the figures designate the same or equivalent

Characteristics.

Embodiments of the invention

Fig. 1A shows an electronic module 10 for a transmission control unit of a

Motor vehicle according to an embodiment of the invention. FIG. 1B shows a section through the electronic module 10 from FIG. 1A.

The electronic module 10 has a printed circuit board 12 with a mounting surface 14 and a contact surface 16 arranged opposite to the mounting surface 14. The mounting surface 14 and the contact surface 16 may refer to two opposite sides of the printed circuit board 12.

For example, the mounting surface 14 may be an upper surface of the printed circuit board 12, and the contact surface 16 may be a lower surface of the printed circuit board 12.

On the mounting surface 14 of the printed circuit board 12, an electronic circuit 18 is arranged with a plurality of electronic components 19. The components 19 may comprise, for example, bare components, surface mounted devices (SMD) and / or application specific integrated circuit (ASIC) devices. The electronic circuit 18 may include sensors, capacitors, printed conductors,

Having connector elements and the like.

Furthermore, the mounting surface 14 and / or the electronic circuit 18 for protection against environmental influences, such as protection against Getriebefuid, at least partially and preferably completely covered with a protective compound 28. Similarly, the electronic circuit 18 may be at least partially embedded in the protective mass 28. The protective compound 28 may also cover one or more flanks 17 or cut edges 17 of the printed circuit board 12. The protective compound 28 may, for example, an epoxy resin-based mass and / or to be a protective varnish. The protective compound 28 may be thermally and / or light-curing.

Furthermore, the electronic module 10 has a base plate 30, which

for example, made of metal, such as aluminum, and / or plastic and which is designed for attachment of the electronic module 10, for example via screw-on points 31, to other components and / or for dissipating heat.

The printed circuit board 12 is arranged with the contact surface 16 on the base plate 30 or is a normal vector of the contact surface 16 directed in the direction of the base plate 30.

Between the circuit board 12 and the base plate 30, a heat-conducting film 32 and / or a thermal adhesive 32 is further arranged, which (r) rests flat against the contact surface and is designed for dissipating heat from the circuit board 12 to the base plate 30. The heat-conducting foil 32 or the heat-conducting adhesive 32 is arranged at least in a partial region 13 of the contact surface 16, preferably in a central central region 13 of the contact surface 16. The heat-conducting foil 32 and / or the heat-conducting adhesive 32 can also extend to an edge of the contact surface 16. The thermal adhesive 32 may serve to secure the printed circuit board 12 to the base plate 30.

The heat-conducting film 32 and / or the thermal adhesive 32 are at one

Outer circumference at least partially, preferably completely, of one

Enclosed adhesive 34, wherein the adhesive 34 is designed to attach the circuit board 12 on the base plate 30. In other words, the printed circuit board 12 is attached by means of the adhesive 34 via an adhesive bond on the base plate 30. The adhesive 34 may denote a potting compound, similar to the protective compound 28, and / or an adhesive.

Next, the electronic module 10 at least one, in particular a plurality of flexible conductor foils 20 for contacting or

Further contact of the electronic circuit 18. The flexible conductor foil 20 may, for example, denote an FPC ("flexible printed circuit"), a flex foil, a flat conductor or the like .The conductor foils 20 each have conductor tracks 26 accommodated between a base layer 22 and a cover layer 24 (see detailed view of FIG. Various conductor foils 20 of a Electronic module 10 can be arranged on different flanks 17 of the respective electronic module 10 and / or protrude from different flanks 17 of the electronic module 10. Also, a plurality of conductor foils 20 may be arranged on an edge 17 of the electronic module and / or protrude from this edge 17.

At least a portion 21 of each conductor foil 20 is between the

Circuit board 12 and the base plate arranged and / or received. The partial regions 21 may be at least partially embedded in the adhesive 34 and / or the adhesive 34 may at least partially surround the partial regions 21 on an outer circumference, so that the

Conductor foils 20 are each fixed. The conductor tracks 26 of each conductor foil 20 are each electrically conductively connected to a contact point 15 arranged on the contact surface 16 of the printed circuit board 12. In other words, the printed circuit board 12 has a plurality of arranged on the contact surface 16

Contact points 15, which are each connected to one of the conductor tracks 26 of a conductor foil. Thereby, as explained in detail above, the contact points 15 and the electrical contacts between the tracks 26 and the pads 15 are fully protected against environmental influences, such as shavings in the transmission fluid caused by short circuits and shunts, and the electronic module 10 can be more compact and robust manner.

The contact points 15 are connected to electrical contacts of the electronic circuit 18. For example, the electrical contacts of the electronic circuit 18 can be integrated by means of the printed circuit board 12

Conductor tracks from the mounting surface 14 through the printed circuit board 12 through to be arranged on the contact surface 16 arranged contact points 15. The contact points 15 do not necessarily have in an edge region of

Can be arranged contact surface 16, but may also be arranged centrally, for example in the central region 13, the contact surface 16. For contacting these contact points 15 arranged in the central area 13, the conductor foil 20 used for contacting has a projection 25 which is finger-like or projecting in a cooperatively configured recess

33 is arranged in the heat-conducting foil 32 or the heat-conducting adhesive 32. To further protect the contact points 15 and / or the electrical contacts between the contact points 15 and the conductor tracks 26 of the conductor foils 20, the electronic module 10 may have a protective compound 36, which the printed circuit board 12 at least in a partial area on an outer periphery and / or on the flanks 17th the circuit board 12 can enclose. The protective compound 36 may consist of the same material as the protective compound 28. Alternatively, the protective compound 36 may be a different material than the protective compound 28, in particular the protective compound 36 may be a silicone-containing standard material.

FIG. 2 shows a detailed view of part of an electronic module 10 according to an embodiment of the invention. Unless otherwise described, the electronics module 10 of FIG. 2 may have the same elements and features as the electronics module 10 of FIGS. 1A and 1B.

In the exemplary embodiment shown in FIG. 2, the electronic module 10 in each case has a contact point 15 arranged on the contact surface 16

Contact pad 38 on. The contact pad 38 protrudes at least partially from the contact surface 16.

For contacting the contact pad 38 with a conductor tracks 26 of the conductor foil 20 is in the cover layer 24 of the conductor foil 20 cooperates with the

Contact pad 38 configured recess 27 introduced. Alternatively, a corresponding recess 27 may be introduced into the base layer 22 of the conductor foil 20. For producing a robust and reliable electrically conductive connection between the conductor track 26 and the contact pad 38, a solder deposit 40 is arranged in the recess 27 and the conductor track 26 is soldered to the contact pad 38. The solder deposit 40 or the conductor track 26 can be approximately by means of ironing and / or light soldering of the recess 27th

opposite side of the conductor foil 20 are soldered ago.

Finally, it should be noted that terms such as "comprising," "comprising," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a multitude. Reference signs in the claims are not to be considered as limiting.

Claims

Electronic module (10) for a transmission control unit of a motor vehicle, comprising:

a printed circuit board (12) having an electronic circuit (18);

a conductor foil (20) with between a base layer (22) and a

Cover layer (24) recorded conductor tracks (26) for electrically contacting the electronic circuit (18); and

a base plate (30),

the printed circuit board (12) having a mounting surface (14) on which the electronic circuit (18) is arranged, and a contact surface (16) opposite the mounting surface (14),

wherein the mounting surface (14) at least partially with a protective mass (28) for protecting the electronic circuit (18) against

Environmental influences is covered, and

wherein the printed circuit board (12) with the contact surface (16) is arranged on the base plate (30),

characterized in that

at least a portion (21) of the conductor foil (20) between the base plate (30) and the contact surface (16) of the printed circuit board (12) is arranged, and in that on the contact surface (16) of the printed circuit board (12) has a plurality of contact points (15 ) is formed, which for contacting the

electronic circuit (18) in each case with a conductor track (26) of the conductor foil (20) are electrically conductively connected.

Electronic module (10) according to claim 1,

wherein a contact pad (38), which protrudes from the contact surface (16) and which is connected to one of the conductor tracks (26) of the conductor foil (20), is arranged at the contact points (15) of the printed circuit board (12) formed on the contact surface (16). electrically conductive is connected.

Electronic module according to claim 2,

wherein the conductor foil (20) in the partial region (21) arranged between the base plate (30) and the contact surface (16) of the printed circuit board (12) has a plurality of embedded in the base layer (22) or the covering layer (24).

having introduced recesses (27),

wherein in each case one of the contact pads (38) of the printed circuit board (12) in one of Recesses (27) of the conductor foil is at least partially accommodated.

4. Electronic module (10) according to one of the preceding claims,

wherein electrical contacts of the electronic circuit (18) from the mounting surface (14) through the printed circuit board (12) through to the arranged on the contact surface (16) contact points (15) of the printed circuit board (12) are guided.

5. Electronic module (10) according to one of the preceding claims,

wherein the conductor tracks (26) of the conductor foil (20) are each connected via a solder depot (40) to the contact points (15) of the printed circuit board (12);

and or

wherein the conductor tracks (26) of the conductor foil (20) are soldered to the contact points (15) of the printed circuit board (12).

6. electronics module (10) according to one of the preceding claims,

wherein the contact surface (16) of the printed circuit board (12) by means of a

Adhesive is attached to the base plate (30).

7. Electronic module (10) according to one of the preceding claims,

wherein between the base plate (30) and the contact surface (16) at least in a partial region (32) of the contact surface (16) a heat conducting foil (32) and / or a Wärmeleitkleber (32) for dissipating heat is arranged

8. electronics module (10) according to claim 7,

wherein the heat-conducting foil (32) and / or the heat-conducting adhesive (32) is enclosed on an outer periphery by an adhesive (34) with which the contact surface (16) of the printed circuit board (12) is fastened to the base plate (30).

9. Electronic module (10) according to one of the preceding claims,

wherein a protective compound (36) for protecting the contact points (15) of the printed circuit board (12) is arranged at least in a partial region of an outer circumference of the printed circuit board (12).

10. Electronic module (10) according to one of the preceding claims, wherein the conductor foil (20) has a projection (25) which is arranged between the contact surface (16) and the base plate (30),

wherein a in the projection (25) arranged conductor track (26) of the conductor foil (20) is electrically conductively connected to a in a central region (32) of the contact surface (16) arranged contact point (15) of the printed circuit board (12).