EP2499314B1 - Method for producing a motor vehicle door latch and associated motor vehicle door latch - Google Patents

Description

The invention relates to a method for producing a motor vehicle door lock, with a housing, further comprising at least one plastic carrier, and with electrical / electronic components in and / or on the housing, which individual or all electrical conductors for contacting the electrical / electronic components in the plastic carrier be integrated in the course of a manufacturing process, and then the electrical traces are applied to the independently produced or produced plastic carrier.

In a generic method according to the EP 0 982 978 A2 are electrical lines firmly connected to a housing and in particular lock housing for a motor vehicle door lock. One or more electrical components can be connected to the electrical lines. The electrical lines have strip conductors of a metallizable plastic, which extend on the housing surface and adhesively connected to the plastic of the associated housing, for. B. are sprayed onto the housing surface. In this way, a housing and in particular lock housing is created, which meets all mounting requirements in terms of assembly and stability and ensures proper electrical contact. However, the definition of the tracks is technologically complex.

In another method according to the DE 43 06 143 A1 The procedure is that the electrical conductor tracks in existing areas of injection molded plastic housing of the lock housing by means of injection molding be embedded. That is, the production of the plastic carrier or the entire housing in the example case and the embedding of the associated electrical conductors in the plastic carrier in question take place simultaneously. The plastic carrier is in this case a part of the housing, which is not mandatory.

Similar goes the DE 692 06 671 T2 which deals with a vehicle door locking device. Here, a metallic circuit element is integrated with a component or the plastic support of the housing by being inserted during molding of the component made of plastic material.

Quite independently it deals with the DE 197 02 205 B4 with a motor vehicle door lock, in which a motor / gear unit is in contact with protruding from the plastic of a housing cover conductor elements. The motor / gear unit is combined to form a structural unit with the aid of a plate-shaped component carrier.

As part of the DE 20 2007 005 076 U1 Such a component carrier or plastic carrier for locking systems will be explained in detail. In fact, such a component carrier essentially consists of a conductor track unit which can be equipped with electrical or electronic components or components. These components may be connectors, microswitches, sensors, motors, etc. used in a motor vehicle door lock. The conductor track unit consists essentially of a flexible conductor foil or generally a so-called stamped grid, which is or which is encapsulated to form a module made of plastic. As a result, a relatively rigid or dimensionally stable component carrier is made available overall, with the help of a secure Positioning of the aforementioned components in or on vehicle door locks can be ensured. This has proven itself in principle.

However, the known approaches encounter problems when the preparation of the plastic carrier on the one hand and its connection with the individual or all electrical conductors on the other hand can not or should not be made simultaneously. One reason for this may, for example, be the special design of the electrical conductor tracks, which are difficult to place within the overall surrounding injection molding tool. Also arise in practice sometimes requirements to equip one and the same component carrier or plastic carrier with different electrical conductors, for example, to realize different motor vehicle door locks by recourse to one and the same housing.

This is sometimes the case when different functions or different installation situations are to be mastered as a module, when resorting to one and the same motor vehicle door lock. All these requirements, the previous state of the art can not or only partially meet. For example, a change in the structure and leadership of the electrical conductors in a stamped grid according to the DE 692 06 671 T2 preceded that a new punched grid is manufactured and inserted for overmolding. - This is where the invention starts.

The invention is based on the technical problem of further developing such a method so that the flexibility is increased and the production costs are reduced.

To solve this technical problem, a generic method for producing a motor vehicle door lock in the invention is characterized in that the electrical conductors are applied to the plastic substrate subtractive structuring, in which the plastic carrier is metallized total on its surface, then a protective coating of the tracks takes place and Finally, the remaining metallization is removed.

In the context of the invention, therefore, the production of the plastic carrier on the one hand and the definition or the application of the electrical conductor tracks on the plastic carrier on the other hand is carried out separately from each other. As a result, there is the fundamental possibility of adapting the electrical strip conductors with respect to their structure, expansion and design to the respective intended use, without the production of the plastic carrier being influenced thereby. The electrical conductors are unchanged in the plastic carrier in question - at least superficially - integrated and experienced on the one hand protection by the plastic carrier and on the other hand stabilized by the plastic carrier. Incidentally, the conductor tracks may still be completely or partially enclosed by the plastic of the plastic carrier. This is not mandatory.

At this juncture, the invention makes use of the known MID (Molded Interconnect Devices) technology, in which the plastic carrier consisting of an electrically nonconducting plastic material on its surface, for example by electrically conductive stamping foils or by local metallization with the desired electrical conductor tracks is equipped. These tracks follow more or less the three-dimensional topography of the plastic carrier. Because the so-called MID technology Combined different approaches, it has not yet prevailed in practice, as the DE 10 2006 037 159 A1 busy. For this reason, a component carrier is here propagated for components to be wired to form an electrical assembly, in which case the components are supported on or in the bottom region of the component carrier. In addition, self-supporting circuit wires extending through a clearance above the ground area are attached to terminal portions of the components. Such a procedure is unsuitable for use in the motor vehicle sector because the circuit wires are partly exposed and thus more or less exposed to both mechanical and environmental influences.

In any case, the present invention proves that the so-called MID technology can be used in the meantime for the production of housings as a whole or of plastic carriers, for example, as components of the housing of motor vehicle door locks. In this case, the respective plastic carrier may be part of the housing, form the housing as a whole or be designed as a so-called component carrier independently of the housing, as described in the context of the previously described DE 20 2007 005 076 U1 is explained. All variants are covered by the invention.

In principle, the procedure is such that the electrical interconnects are applied in a subtractive manner to the plastic carrier in question. In the subtractive structured order of the electrical lines or conductor tracks, the procedure is such that the plastic carrier in the relevant areas is completely equipped with a metallic coating (on its surface) or metallized overall. After that For the most part, this metallization or the associated metal coating is removed, namely in the areas which serve as free areas between the remaining conductor tracks. In this approach, it is, of course, on the fact that the plastic carrier itself is designed to be electrically non-conductive, as already explained in one piece. In any case, the different basic procedures allow a particularly great flexibility in the definition of the electrical conductors and their attachment to the associated plastic carrier. In this case, the plastic carrier may be the entire plastic housing of the motor vehicle door lock, that is to say the casing of the motor vehicle door lock with the recessed metal lock case, which is usually made of metal. In addition, the plastic carrier but also only represent a part of the housing. In addition, in the context of the invention, the option that the plastic carrier as a component carrier in the sense of DE 20 007 005 076 U1 is designed.

In any case, the invention intentionally omits, for example, a prefabricated stamped grid, which is inserted into an injection mold and molded with plastic. Rather, the interconnects can be flexibly adapted to the respective plastic carrier. As a result, various variants of the motor vehicle door lock can be realized by resorting to one and the same injection mold for the plastic carrier or the housing. As a result, the manufacturing costs can be reduced while at the same time achieving increased flexibility. Here are the main benefits. The plastic carrier can be produced in the course of an injection process.

In order to facilitate the understanding of the invention, a further option for an additive metallizing coating is disclosed, which does not form part of the invention. In this case, the conductor tracks are applied to the plastic carrier by the plastic carrier in the region of the subsequent conductor tracks undergoes - at least local - metallization. Alternatively, it is also possible to work with electrically conductive embossing foils or conductor foils or conductor foils which form a connection with the plastic carrier. For this purpose, the so-called hot stamping has proven to be particularly favorable.

The electrical conductors can be applied as metallic conductors on the otherwise injection-molded plastic carrier. It can be used in detail on a two-component injection molding process become. In this context, a first non-metallizable and electrically non-conductive plastic forms a base body, while another second electrically non-conductive plastic can be made metallizable and defines the electrical conductor tracks. D. h., The other second and metallizable plastic forms a printed circuit board layout.

The metallization of the other second plastic can for example be made as in the DE 199 07 245 A1 will be described in detail. In this case, usually a thermoplastic plastic is used as the second plastic, for example polyamide, which can be electrolessly and wet-chemically metallized. For this purpose, the polyamide surface is first roughened and then a metal layer is deposited. In this context, a composite of two thermoplastic materials is first prepared, of which one component, the second plastic, is metallizable. The other component, the first plastic, remains completely unaffected by the subsequent chemical action of the metallization electrolytes. As a result, the overall plastic carrier can be produced in such a way that metallic properties are present in part in the region of the desired conductor tracks. In this case, the metallizable plastic or the second plastic in the form of electrical conductors can be easily structured. For this purpose, first the first plastic is injected and then encapsulated by the metallizable second plastic, or vice versa.

At this point, it is further proposed to use as a second plastic a metallizable and electrically non-conductive plastic, wherein the layout of the tracks is shown sublimely. The first non-metallizable plastic, which is also electrically non-conductive, then fills the open areas between the individual tracks. Instead of using a sublime design to realize the Leikerbahnlayouts too work, but also recesses can be used. In this case, the first plastic is again not metallizable and electrically non-conductive and are formed in the first plastic, the subsequent traces as wells. These recesses are then filled with the second metallizable and electrically non-conductive plastic.

In any case, the procedures described are those in which the electrical conductor tracks are applied to the actual plastic carrier in an additive metallizing manner. These approaches are not part of the invention, but merely serve to facilitate understanding of the invention.

Within the scope of an embodiment of the invention, it is provided that the plastic carrier to be finished on the surface with the strip conductors is firstly activated and structured on its surface. Then, a metal layer is applied to the individual structures or the plastic undergoes a corresponding metallization. Both approaches can be advantageously realized with a laser. In fact, with the help of such a laser in the plastic carrier, the subsequent conductor track as it were "inscribed". As a result of the laser irradiation, the plastic carrier can be converted into an electrically conductive state in the irradiation region of the laser. Then an additional metallization is not required, but rather the plastic of the plastic carrier is modified accordingly. Of course, this requires that the plastic itself is designed to be metallised.

Thus, it is conceivable, for example, to work with a polymer with the addition of additives for the realization of the metallizable plastic carrier. With the aid of the laser beam can now cause a chemical reaction of the additive with the polymer, as a result of which the previously electrically insulating polymer is converted into an electrically conductive material. Alternatively, it is also possible that in the polymer for the preparation of the plastic carrier from the outset electrically conductive particles are incorporated. These can be combined with one another by irradiation with the laser light merge and define the desired electrical trace. In this case, so to speak, subtractive structuring is used.

The same applies to the case that the plastic carrier is metallized overall and then a protective coating of the conductors takes place. Subsequently, the remaining metallization is then removed and there remain only the protected by means of the protective coating tracks. The metallization of the surface of the plastic carrier can be carried out again by means of laser irradiation, with inter alia Nd: YAG laser or fiber laser can be used. In the case of subtractive laser structuring, therefore, the entire surface of the plastic carrier is first of all metallized by means of laser radiation or, for example, by measurement. Subsequently, the structure of the desired printed conductors is defined by means of a protective coating. This may be an initially liquid and then curing plastic coating, which is resistant to subsequent etching processes. In any case, after this process, the metallized surface of the plastic carrier, which is not protected by the Ätzresist, then etch away.

The same applies to the mask exposure process. In this case, first of all the entire surface of the plastic carrier can be metallized in a customary manner, that is to say by depositing a metal or copper layer. A metallization by laser irradiation is conceivable. This metallized component surface then undergoes laser structuring by structuring the previously applied plastic layer or layer resistant to the etching process. The remaining exposed copper layer or metal layer is then etched away. In the mask exposure method, the plastic support is again, for example wet-chemically, with a metallic coating, such as a thin copper layer, equipped. A photoresist coating is applied to this copper layer. This coating can be exposed using an example three-dimensional photomask, for example, with UV light. After applying the thus produced etching mask, the photoresistive layer and the copper which is no longer needed can be etched away.

In addition to these subtractive structuring methods, it is finally also conceivable to back-coat a conductor foil with a plastic for the purpose of depicting the plastic carrier with the applied electrical conductor tracks. In this case, the actual printed circuit film or conductor tracks are inserted as such in an injection mold and back-injected with suitable plastics, so that it is located on the surface side of the plastic carrier and are as it were applied to this or are.

As a result, a method and an associated motor vehicle door lock are described, which are characterized by a particularly flexible production of the plastic carrier. In fact, the plastic carrier, which may be an electronic component carrier, is manufactured independently of the electrical conductors which are applied to the already produced or still to be produced plastic carrier. For this purpose, the invention relies on a per se known to partially modified MID method. Here are the main benefits.

Fig. 1

das erfindungsgemäße Kraftfahrzeugtürschloss in einem Teilausschnitt und

Fig. 2

die eingesetzte Leiterbahnfolie in einer schematischen Übersicht.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment; show it:

Fig. 1

the motor vehicle door lock according to the invention in a partial section and

Fig. 2

the used conductor foil in a schematic overview.

In the figures, a motor vehicle door lock is shown, which is of conventional design, that is a not explicitly illustrated locking mechanism with a catch and pawl has. Evident is a locking lever or central locking lever 1, which by means of a drive unit 2, 3, for example, in its positions "unlocked" and "locked" about an axis 4 can be pivoted. In the same way, an inner locking lever 5 may provide for corresponding pivoting movements of the central locking lever 1. Finally, the basic structure is still a housing 6, which at the transition from the Fig. 1 to Fig. 2 partially opened or removed. In fact, the housing 6 is composed of an upper housing part 6a and a lower housing part 6b.

In addition, it can be seen a connection socket 7 in the upper housing part 6a and two switches 8 in the upper housing part 6b which query the position of the rotary latch and the central locking lever 1. This is of course only to be understood as illustrative and not restrictive. The connector 7 and the two switches 8 are as well as the electric motor 2 via a in the Fig. 2 Basically illustrated conductor sheet 9 electrically connected to each other. That is, any signals of the switch 8 are transmitted to a remote control unit via the conductor foil 9 and finally the connection socket 7 or a plug inserted therein. In addition, the connection socket 7 ensures the control of the electric motor 2 with the interposition of the conductor film 9.

In the context of the invention, the one half of the housing or the upper housing part 6a acts as a plastic support 6a or component carrier in the sense of DE 20 2007 005 076 U1 , For the plastic support 6a carries, inter alia, the connector 7 and can also be equipped with other electrical / electronic components. In addition, the component carrier 6a is equipped with the conductor foil 9, which is integrated in the component carrier 6a - at least in the region of its surface. The surface in which the printed circuit film 9 is integrated or onto which it is applied is the surface facing the lower housing part 6b and consequently the switches 8 and the electric motor 2.

For the production of the housing half or the component carrier 6a, this is first formed by means of a plastic injection molding tool. Subsequently, electrical conductors are applied. In the context of the embodiment, for this purpose, a printed circuit foil 9 punched out of a metal foil is applied to the plastic carrier 6a in question by hot stamping. This corresponds to an additive metallizing order, which is not the subject of the method according to the invention and only serves to clarify the fundamental principle.

In fact, in this process, the conductor film 9 is punched out of the metal foil and impressed with the simultaneous application of pressure and heat in the plastic carrier 6a. As a result, the strip conductor 9 dips into the plastic support 6a on the surface side and at least slightly and ensures plasticized and displaced plastic mass corresponding to the fact that the strip conductor 9 is optionally sealed by the previously molten plastic. In principle, after this process, however, a potting compound can also be applied to the printed circuit film 9 for its protection, or the printed circuit film 9 can undergo a potting coating.

Claims (4)

1. A method for manufacturing a motor vehicle door lock comprising a housing (6), and furthermore comprising at least one plastic carrier (6a) and electric/electronic components (7, 8) in and/or on the housing (6), wherein

   - individual or all electric strip conductors for contacting the components (7, 8) are integrated into the plastic carrier (6a) in the course of a manufacturing operation, and wherein

   - the electric strip conductors are applied onto the plastic carrier (6a) which has been manufactured or is to be manufactured independently thereof,

   characterized in that

   - the electric strip conductors are applied in a subtractive structuring manner on the plastic carrier, in that

   - the entire surface of the plastic carrier (6a) is metallized, afterwards the strip conductors are coated with a protective layer and the other metallizing coating is finally removed.
2. A method according to claim 1, characterized in that the plastic carrier (6a) is injection moulded.
3. A method according to one of the claims 1 to 2, characterized in that the plastic carrier (6a) is surface activated and surface structured, wherein the metal layer will be afterwards applied onto the surface structured in such a way.
4. A method according to one of the claims 1 through 3, characterized in that the electric strip conductors will be back-injected with a plastic.

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