DE19832062A1 - Mounting for control circuit chip in motor vehicle - Google Patents

Abstract

The control circuit is used in a motor vehicle. A circuit module or chip is held by at least two edges in a baseplate (1) which may be bolted to a frame element (5) which may be made of a nonconducting plastics material. The frame has a number of bores in its sides through which conductor rods (9) pass. There are plates (14) at the ends of the rods which contact the edge of a conductor plate (11). The conductor plate has sealing ribs (8), and may contain a number of conductor paths. There may be a sheet of polyamide material on either side of the conductor paths, the sheets being held together by an adhesive layer. The edges of the conductor plate may be laser welded to the circuit chip (X1) and to the conductor rods (X2).

Description

The invention relates to a control device for a motor vehicle according to the preamble of claim 1. Furthermore, the Invention a method for producing such Control device according to the preamble of claim 11.

It is already known in engine and transmission control units the motor vehicle assembly to be controlled (i.e. engine or Ge drives) to integrate. Such integrated control devices must be oil-tight over a wide temperature range (about -40 ° C to 140 ° C) remain functional and high Have level of vibration resistance (up to about 40 g).

In a known transmission control unit are in a Plastic sealing frame, pressed-in metal pins, oil-tight lei created through the housing wall. The electrical contacting of the housed in the housing Control switching is done by bonding. The press-in stations and the bond connections fulfill the above requirements regarding oil tightness and vibrations resistance. The disadvantage, however, is that both the housings S bushings using press-in pins as well as internal electrical contacting by means of bond connections construct extremely cost-intensive both in terms of production and manufacturing technology ve measures, the cost being proportional to the an number of press-in pins / bond connections increase.

In the older, unpublished German patent application Message DE 197 13 657.5 is a motor vehicle control unit wrote, in which a flexible conductor foil in the area a seal between a housing base plate and a Housing cover is passed through. For electrical contact tation based on an LTCC substrate (Low Temperature Cofired Ceramics) assembled circuit carriers and  the conductor carrier has an area in which they overlap and in which the circuit carrier by means of an electrically lei tendency adhesive electrically connected to the conductor track carrier is. This control unit is characterized by low Her positioning costs. The disadvantage, however, is that the electri Contacting the circuit carrier by means of contact adhesive not always a sufficient level of mechanical Fe stability and vibration resistance guaranteed.

In the older, unpublished German patent application message 197 12 842.4 a transmission control unit is described, the housing of which serves as a supporting body housing cover made of plastic. In the housing cover are electrical Head encased. The ends of these conductors protrude from the housing sedeckel and are for contacting the flexible Lei sheet in the insulation area provided on the floor plate side Chen pressed with conductor tabs.

The object of the present invention is to provide a control unit create in which a mechanically stable and electrically si Chere electrical contacting in a housing of the Control unit housed circuit carrier, in particular LTCC substrate is realized in a cost-effective manner. Fer ner aims the invention, a method of manufacture To specify such a control unit, the Erfor a mechanically stable and safe electrical Contacting the circuit carrier in a cost-effective manner realized.

To solve this problem, the characteristic features of claims 1 and 11 provided.

According to the invention by laser soldering or laser welding placed electrical connections between the circuit carriers and the flexible conductor track carrier meet the requirements changes in terms of mechanical strength and electri full conductivity. At the same time they are  Weld or solder connection provided according to the invention make production technology simpler and therefore more economical to produce more than the previously used bond connections. In particular, no gold-plated contact surfaces of the Conductor tracks of the conductor track carrier as they are when bonding are required. Compared to the beginning written contact adhesive will lower electrical over gearing resistance and higher vibration resistance achieved. Another advantage of the invention is that it is different than with contact gluing, where the adhesive is used to harden binding over an extended period of time an elevated temperature is required for laser welding or soldering to the con clock formation required increased temperature selectively and briefly is applied early, which creates the risk of thermal Damage to circuit or plastic parts minimized and also a faster and therefore more cost-effective Manufacturing process is made possible.

An advantageous embodiment of the invention features differs in that the bottom plate of a peripheral frame menelement is surrounded that electrical in the frame element Conductors are guided in the area of the inner circumference of the frame mens exposed contact sections that the Lei terbahnträger one over the exposed contact sections bearing second contacting section, and that conductor tracks guided into the second contacting section via second laser welding or laser soldering points with the free lying contact sections of the electrical conductor elek trisch conductively connected. Since in this case the elec trical connection between the circuit carrier and the fle xiblen conductor carrier on the one hand and the flexible Lei terbahnträger and the guided in the frame element electrical Leaders, on the other hand, through the same contacting process (Laser welding or laser soldering) takes place, the Effort for the production of the flexible conductor foil as for the execution of the corresponding contacting stepped considerably.  

Basically, laser welding or laser soldering can be done directly executed on the copper conductor tracks of the conductor track carrier become. This leads from the metal surface of the conductor track absorbed light for local heating of the conductor track and thus to melt the metal surface. Through out sufficiently short pulse times of the laser can be guaranteed be that the flexible conductor track carrier in this process is not impaired or harmed.

Another measure, in particular under the aspect of Increasing the mechanical strength of the connection of Be interpretation is that the first and / or the two ten laser welding or laser soldering points each of several individual welding or soldering points are set up.

In the event that both the circuit carrier / conductor track and also the conductor track / conductor connection by laser welding or laser soldering is produced, be marked preferred embodiment of the invention in that the exposed contact sections of the electrical conductors and the contact elements arranged on the circuit carrier ko are planar. In this way, a particularly simple and fast execution of the laser welding / laser soldering step done because all connection points in a common The focal plane of the laser lies and is easily accessible from above are.

Another cost-cutting aspect of the present invention manure is that the bottom plate as a substantially Chen flat metal stamped part executed can be. Unlike with conventional realization for in which the electrical connection of the conductor tracks the bottom of the circuit carrier and therefore the Circuit carrier provided on a base plate side Increase must be put on, is due to the Surface-side training of laser welding / laser soldering  do not make a corresponding increase in the base plate compelled. Consequently, this can be as simple as, for example Stamped part made of Al inexpensively manufactured the.

A preferred embodiment of the invention The process is characterized in that before the execution of the Laser welding or laser soldering step using a pressure stamp a predeterminable pressing force on the first and / or the second contacting section is exercised. The pressure force causes an even contact of the welding the / soldering conductor track areas of the flexible conductor track carrier gers to the electrical contact elements of the circuit gers and / or the exposed contact sections of the elec tric leader. This causes that when the La serlichtes a defined and good heat transfer between the respective welding or soldering partner is present, and thus facilitates the manufacture of mechanical and electrical tric flawless connections.

Another advantageous embodiment of the invention ßen procedure is characterized in that in the context of Positioning step a visual monitoring of the position of the Conductor tracks of the first contacting section relative to the position of the contact elements of the circuit carrier and / or visual monitoring of the position of the conductor tracks of the two th contacting section relative to the location of the free lying contact sections of the conductors. This about guarding can be carried out in a simple manner because of the conductor web carrier in both contacting areas the more massive Contact partner (circuit carrier or conductor section te of the frame element) overlaid and thus recognizable from above is cash. It enables a high positioning accuracy of the Conductor track carrier, causing contacting errors caused by incorrect po positionings can be practically excluded.  

The laser welding or laser soldering on the two cones Tacting sections of the conductor track carrier are preferred wise in a sequential or automated manner Lich the first or second contact sections of old in a common laser welding or laser soldering station tion executed. Due to the identical Kontaktierungsver drive on the first and the second contacting section the conductor track carrier and the limited size of the ge entire arrangement, it is possible and preferred in this case the bottom plate with circuit carrier in the laser welding or Hold the laser soldering station in a fixed position and the laser beam by means of an optical beam guiding arrangement from Move weld / solder joint to weld / solder joint.

Another preferred variant of the Ver driving is by laser welding or laser soldering place to detect reflected light and to determine the achieved quality of laser soldering or laser welding evaluate. This enables a simple but effective Check the connections achieved. Furthermore, in this Case be provided, the energy emitted by the laser quantity or power or other laser parameters depending of the determined quality of the laser welding or Control laser soldering. This is for example a ge targeted re-welding or re-soldering of inferior quality sufficient or insufficient connections.

The invention is described below in an exemplary manner Explained with reference to the drawing; in this shows:

Figure 1 is an exploded view of the structure of a control device according to the invention without control device cover. and

Fig. 2 is a schematic partial sectional view of a control device according to the inven tion, in which an electrical contact point between circuit carrier and conductor carrier and an electrical contact point between conductor carrier and an electrical element included in the frame element is shown cheerfully.

According to Fig. 1, a control unit preferably of a alu minium existing metallic base plate 1 as well as serving as a circuit carrier LTCC substrate 2 made of ceramic. The LTCC substrate 2 is equipped with electronic components in a manner not shown and in the assembled state was glued to the underside of the metal base plate 1 via a heat-conducting adhesive. The base plate 1 serving as a heat sink can be produced in a simple manner as an Al stamped part. In its peripheral region, it has an offset 3 provided with ends 4 holes 4 gene.

In Fig. 1, a preferably made of glass fiber reinforced polyamide frame element 5 , a provided with a Zen tralausschnitt 6 flexible conductor sheet 7 with molded on both sides circumferential seal 8 and an electrical conductor 9 is shown. Instead of the gasket 8 molded on both sides, circumferential gaskets inserted into Dichtnu th of the base plate or the cover can also be provided. The frame member 5 with the holes 4 aligned through holes 10 through which the bottom plate 1 , the frame member 5 and a not shown in Fig. 1 housing cover via screw connections or rivets are firmly coupled. The electrical conductor 9 is guided in the frame element 5 and connects the control unit with electrical components (sensors, actuators) in the transmission.

The conductor track film 7 has first contacting sections 11 , 11 ′ arranged on the edge side to the central cutout 6 and within the area delimited by the circumferential seal 8 . In the assembled state, the first contacting sections 11 , 11 'of the conductor foil 7 correspond to corresponding edge-side contact zones 12 , 12 ' of the LTCC sub strate 2 and are electrically connected to them in a manner to be described in more detail below. The housing cover, not shown, is placed in the assembled state on the circumferential seal 8 of the conductor foil 7 and forms an oil-tight conductor bushing between the housing cover and the flexible conductor foil 7 . Outside the seal 8 , the conductor track film 7 is connected to the second contacting sections 13 , 13 'shown by dashed lines in a manner to be described in more detail with flattened exposed contact sections 14 of the electrical conductor 9 .

Fig. 2 shows a partial sectional view of a motor vehicle control unit in the assembled state without a housing cover. The control device shown in Fig. 2 differs from the control device shown in Fig. 1 only to the extent that the metallic base plate 1 is extrusion-coated by the plastic frame element 5 .

The conductor track film 7 is constructed in a manner not shown from a lower polyimide base film and an upper polyimide cover film, between which conductor tracks are embedded in an adhesive layer. In Fig. 2 it can be seen that the inner, first Kontaktierungsab section 11 of the conductor foil 7 overlays the contacting zone 12 of the substrate 2 . In this case, the conductor track film 7 is oriented relative to the substrate 2 such that one of the conductor tracks, not shown, comes to lie directly above an electrical contact element, also not shown, in the contact zone 12 of the LTCC substrate 2 . In an ana logic manner, in the second, outer contacting section 13 of the conductor track film 7, a conductor track is un indirectly above the flattened, exposed contact section 14 of the electrical conductor 9 which otherwise runs in the frame element 5 . The electrical connec tion points between the substrate 2 and the conductor foil 7 on the one hand and the conductor foil 7 and the electrical conductor 9 on the other hand are marked by the arrows X1 and X2 and are produced according to the invention by laser welding or laser soldering.

In the case of laser soldering, one of the connection partners is preferably the flexible conductor foil with a solder Layering, especially tinning. With the laser welding, there is no solder coating, so that the connection partners are usually welded directly to one another the. Furthermore, the surfaces of the conductor tracks can be through an organic coating to be tarnish proof prevent possible oxidation.

The contacting zone 12 of the LTCC substrate 2 and the flattened exposed contact section 14 of the conductor 9 lie essentially in one plane and are only a relatively short distance apart. This is favorable in terms of manufacturing technology, since the laser welding or laser soldering points X1, X2 can then be produced in a welding or soldering machine provided for this purpose with a high clock rate by the same laser. Without changing the position of the control unit assembly in the machine, the laser beam is guided from one welding point (soldering point) to the next through a process optic.

Another measure that is favorable in terms of production technology exists in the welding or soldering partner during manufacture the welded / soldered connections in a manner not shown to fix with a pressure stamp and with defined Push force against each other to create a gap-free system guarantee.

A major advantage of the method according to the invention is that the position of the conductor track film 7 is monitored optically before and during the execution of the laser welding / laser soldering step and the position of the laser focus can be readjusted if necessary.

Furthermore, the method according to the invention enables qualification monitoring of the achieved welding / soldering connections as well if necessary, an improvement in the quality of these compounds through automated readjustment of the laser parameters (e.g. Fo cal level, laser power, pulse duration) and / or by a targeted re-welding or re-soldering. For this purpose that of the laser welding / laser soldering point X1, X2 during the Welding / soldering process reflected laser light from an opti and received by a downstream receiver Evaluation electronics analyzed. This can be used, for example during a welding process, determine whether it is suitable for a mecha nically stable and electrically safe contacting required sufficient melting of the contact surfaces of the two welding partners took place.

The welded / soldered connections can, for example, with a pulsed Nd: YAG laser can be produced. After completion The complete electri circuit carriers are cast with Silgel. The Sil gel serves as additional protection against mechani cal impairments, such as those caused by a transmission or vibrations occurring in an engine can, and on the other hand as corrosion protection in particular also in the area of contact points.

After the optional Silgelverguss the housing cover, not shown in FIGS . 1 and 2 is placed and firmly connected to the base plate 1 and the frame element 5 in the manner already described.

The seal 8 for the oil-tight line bushing can be provided al ternatively to the manner shown in FIGS . 1 and 2 also in a sealing groove in the metal base plate 1 , preferably made of aluminum.

Claims (19)

1. Control device for a motor vehicle, which has:

• - a base plate ( 1 );
• - A housing cover, the device via at least one housing seal ( 8 ) is tightly coupled to the base plate ( 1 );
• - A circuit carrier ( 2 ) attached to the base plate ( 1 ); and
• - A flexible conductor carrier ( 7 ) with integrated electrical conductor tracks, the device in the area of the housing seal (s) ( 8 ) between the base plate ( 1 ) and the housing cover is passed through; characterized by
• - That the conductor track carrier ( 7 ) has a contacting zone ( 12 , 12 ') of the circuit carrier ( 2 ) overlying the first contacting section ( 11 , 11 '); and
• - That in the first contacting section ( 11 , 11 ') guided te conductor tracks via first laser welding or Laserlötstel len (XI) with in the contacting zone ( 12 , 12 ') existing contact elements of the circuit carrier ( 2 ) are electrically conductively connected.

2. Control device according to claim 1, characterized in

• - That the base plate ( 1 ) is surrounded by a peripheral frame element ( 5 );
• - That in the frame element ( 5 ) electrical conductors ( 9 ) are guided, which have exposed contact sections ( 14 ) in the region of the inner circumference of the frame element ( 5 );
• - That the conductor track carrier ( 7 ) has an exposed con tact sections ( 14 ) overlapping second Kontaktierungsab section ( 13 , 13 '); and
• - That in the second contacting section ( 13 , 13 ') led tracks via second laser welding or laser solder joints (X2) with the exposed contact sections ( 14 ) of the electrical conductors ( 9 ) are electrically conductively connected.

3. Control device according to one of the preceding claims, there characterized in that the first and / or the second La welding or laser soldering points (X1; X2) each of several individual welding or soldering points. 4. Control device according to one of claims 2 and 3, characterized in that the exposed contact portions ( 14 ) of the electrical conductors ( 9 ) are guided out substantially flat. 5. Control device according to one of claims 2 to 4, characterized in that the exposed contact sections ( 14 ) of the electrical conductor ( 9 ) and the contact elements arranged on the circuit carrier ( 2 ) are coplanar. 6. Control device according to one of the preceding claims, characterized in that the conductor track carrier ( 7 ) surrounds the scarf device carrier ( 2 ) on all sides. 7. Control device according to one of the preceding claims, characterized in that the housing seal ( 8 ) with the conductor track carrier ( 7 ) is connected, in particular is sprayed on this. 8. Control device according to one of the preceding claims, characterized in that the base plate ( 1 ) is an essentially all-over flat metal stamped part. 9. Control device according to one of the preceding claims, characterized in that the base plate ( 1 ) is provided with a sealing groove for receiving the housing seal ( 8 ). 10. Control device according to one of the preceding claims, characterized in that the circuit carrier ( 2 ) is glued to the base plate ( 1 ) via a heat-conducting adhesive. 11. A method for producing a control device for a motor vehicle, characterized by the steps:

• a) providing a base plate ( 1 );
• b) applying a circuit carrier ( 2 ) to the base plate ( 1 );
• c) Positioning a flexible conductor track carrier ( 7 ) with integrated electrical conductor tracks, such that a ster contacting section ( 11 , 11 ') of the conductor track carrier ( 7 ) comes to rest over a contacting zone ( 12 ) of the circuit carrier ( 2 );
• d) laser welding or laser soldering of conductor tracks in the first contacting section ( 11 , 11 ') with contact elements of the circuit carrier ( 2 ) present in the contacting zone ( 12 ) to achieve electrically conductive connections in the form of laser welding or laser soldering points (X1); and
• e) Installation of a housing cover which can be coupled tightly to the base plate ( 1 ) via a housing seal ( 8 ).

12. A method for producing a control device according to claim 11, wherein the base plate ( 1 ) is surrounded by a circumferential frame element ( 5 ) in which electrical conductors ( 9 ) are guided, which are exposed in the region of the inner circumference of the frame element ( 5 ) Have contact sections ( 14 ), characterized by the steps:

• f) Positioning a second contacting section ( 13 , 13 ') of the flexible conductor track carrier ( 7 ) with integrated electrical conductor tracks in such a way that the second contact section ( 13 , 13 ') of the conductor track carrier ( 7 ) above the exposed contact sections ( 14 ) of the electrical conductor ( 9 ) comes to rest; and
• g) laser welding or laser soldering of in the second contact processing section ( 13 , 13 ') guided conductor tracks with the exposed contact sections ( 14 ) of the electrical conductors ( 9 ) to achieve an electrically conductive connection.

13. The method according to any one of claims 11 or 12, characterized in that before step d) and / or step g) via a pressure ram a predetermined pressure force on the most and / or the second contacting section ( 11 , 11 '; 13 , 13th ') is exercised. 14. The method according to any one of claims 11 to 13, characterized in that as part of step c) a visual monitoring of the position of the conductor tracks of the first Kontaktie approximately section ( 11 , 11 ') relative to the position of the contact elements of the circuit carrier ( 2nd ) and / or that in step f) the position of the conductor tracks of the second contacting section ( 13 , 13 ') is visually monitored relative to the position of the exposed contact sections ( 14 ) of the conductors ( 9 ). 15. The method according to any one of claims 11 to 14, characterized ge indicates that steps d) and g) in automated Consecutively or alternately in a common manner men laser welding or laser soldering station. 16. The method according to claim 15, characterized in

• - That in step d) and / or step g) the base plate ( 1 ) with circuit carrier ( 2 ) in the laser welding or laser soldering station is held in a fixed position and
• - That by means of an optical beam guiding arrangement, the laser beam from the welding / soldering point (X1; X2) to the welding / soldering point (X1; X2) is moved.

17. The method according to any one of claims 11 to 16, characterized ge indicates that in step d) and / or step g) that of a laser welding or laser soldering point (X1, X2) reflected Light captured and used to determine the quality achieved Laser welding or laser soldering is evaluated. 18. The method according to claim 17, characterized in that one or more laser parameters, especially those from the laser  amount of energy given off during a welding or soldering process or performance depending on the determined quality the laser welding or laser soldering can be controlled. 19. The method according to any one of claims 11 to 18, characterized in

• - That the base plate ( 1 ) is provided with a sealing groove,
• - That the housing seal ( 8 ) is connected to the conductor track carrier ( 7 ), in particular molded onto it, and
• - That the sealing groove is used in step c) as a positioning aid.