DE102009053512A1 - Method and device for producing a composite component, composite component - Google Patents

Abstract

The present invention describes a method for producing a composite component in which a component or a partial area of a component is provided with an adhesive layer which has a microrough surface with undercuts, the undercuts being designed so that a liquid hardenable material flows from behind. The micro-rough surface is brought into contact with the liquid hardenable material so that the liquid hardenable material flows behind the undercuts. Furthermore, a device for producing a composite component and a composite component are described.

Description

The present invention relates to a concept for producing a composite component, as it may be, for example, a metal part with a plastic sheath.

Composite components allow the combination of different material properties in one component. The encapsulation of metal parts with thermoplastic materials is therefore widely used today in a wide variety of applications. Often stamped grid are overmolded to lead out contact elements from a housing or to realize an electrical wiring structure on a plastic component. Furthermore, in the production of plug-in elements such. B. power strips often metallic plug contacts such. B. connector pins and sleeves encapsulated with thermoplastics. In addition, however, other metal-plastic composites are conceivable, such as for applications in pipes and vessels for liquids and gases or mechanically stressed components, even if it depends on a good mechanical power transmission.

As a material for metallic inserts often come copper or copper alloys such. B. CuSn6 used. Depending on the application, the metal inserts may still be provided with a final layer, such as tin. As thermoplastics often technical thermoplastics or high-performance thermoplastics such as polyamide (PA), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) or liquid crystal polymers (LCP) are used.

For many applications, a media- and / or pressure-tight connection of insert to thermoplastic is required. However, if both materials have no chemical affinity to each other, then a gap formation may occur after the encapsulation, which due to the capillary action can lead to the penetration of a medium, such as, for example, air or liquids. During mechanical or thermal stress during operation, the gap may increase due to continuous stress and eventually lead to failure of the component.

If metal inserts are encapsulated with a thermoset, such. As in the transfer molding (so-called "transfer molding"), it can be assumed here as a rule of a higher affinity of thermoset to metal insert. Since non-crosslinked thermosets still reactive functional groups of the polymer are present, they can then ideally bind directly to the metal of the insert cohesively, resulting in improved adhesion between the two components.

In order to achieve a similar effect when encapsulating with thermoplastics, metal insert parts are often pretreated prior to encapsulation with adhesion promoters, which should enable a good cohesive connection with the thermoplastic. For this purpose, for example, adhesion promoters based on silanes or epoxides are used. Depending on the material combination, a specific adhesion promoter must be used. However, for some applications, such. B. in high thermal stress and exposure to aggressive media, the connection of thermoplastic to insert is not always sufficient, d. H. the adhesion between thermoplastic and insert is too low.

In printed circuit board technology, suitable copper foils are micro-roughened by brushing, but also by electrochemical processes such as pulse coating (also known as "pulse plating" in the production of multilayer printed circuit boards) in order to achieve the greatest possible adhesion of the so-called "prepreg" (unhardened thermoset Plastic matrix) on the microrough copper. Due to the micro-rough surface, a mechanical positive connection can be formed between the plastic matrix and copper. Furthermore, the microrough layer causes an enlargement of the surface and thus an increase of the adhesion forces. As a further measure, the adhesive strength can be further improved by chemical aftertreatment of the microrough copper foil, usually by oxidizing media.

The hot embossing MID technology uses micro-rough copper foils with defined brittleness, in order to obtain a very high adhesion of the hot-stamped conductor structures on suitable thermoplastics. In order to produce this microroughness on the copper foils, similar to the copper foils used in printed circuit board technology, a sticking and wipe-resistant coating of copper dendrites (so-called "treatment" or "treatment layer") is deposited by means of "pulse plating". The deposition can be carried out, for example, from a sulfuric acid copper electrolyte, which passes through the film to be coated continuously. Through targeted optimization of z. B. pulse height, pulse length and pulse spacing, the adherent deposition of copper dendrites can be achieved. Such a pulse regime leads to a firmly rooted on the surface "cauliflower" treatment with high strength. In addition, this "cauliflower-like" treatment can be further treated by means of oxidizing media (black oxidation - so-called "black oxide"). If such a copper dendrite-coated (so-called "treatment-coated") copper foil is impressed on a thermoplastic with a heated, structured embossing stamp, it is thus possible to produce highly adhesive conductor track structures on thermoplastic components. Of the Thermoplastic material softening by the embossing process claws mechanically with the micro-rough treatment of the copper foil, which leads to a very stable positive connection between the two components and thus to a very good adhesive strength of the conductor structures.

Based on the cited prior art, it is an object of the present invention to provide a concept which allows a better adhesion of a shell of a composite component with a component to be joined of the composite component.

A method according to claim 1, an apparatus according to claim 15 and a composite component according to claim 18 solve this object.

A core idea of the present invention is based on the finding that a composite component with a greater adhesion between a shell of curable material of the composite component and a component to be joined can be created if the component is provided with an adhesive layer having a micro-rough surface with undercuts and the microrough surface is contacted with liquid curable material so that the liquid curable material flows behind the undercuts.

An advantage of the present invention is that, by utilizing liquid curable material in conjunction with a microrough surface having undercuts, the backbone of the liquid curable material of the undercuts allows the liquid curable material to cling to the microrough surface to produce such a cohesive and adhesive bond with the component, as this is previously possible from the prior art.

The liquid curable material can be cured for example by cooling, irradiation or chemical processes.

The liquid curable material may be, for example, a thermoplastic or a thermoplastic elastomer, or an elastomer or a thermoset which, utilizing the concept of the present invention in conjunction with a member made of, for example, metal, a strong bond of the thermoplastic or thermoplastic elastomer or elastomer or duromers with the metal, comparable to an adherent bond of a thermoset with a metal. It is thus a more adhesive bond between the thermoplastic and the metal component allows as this is possible in known from the prior art adhesion promoters.

Further, in embodiments of the present invention, the component may be contacted with the liquid curable material by overmolding (e.g., completely enclosing the component with liquid curable material) or by injection molding (e.g., location-selective coating of the component with liquid curable material). In contrast to the known methods of hot embossing, the overmolding or injection molding allows any shape and, in particular, the use of solid components for encapsulation or gating in contrast to films which are coated.

Another advantage of the present invention is that the shape of the composite component to be produced is freely selectable by the encapsulation of a component with liquid curable material. In this case, the shape can be predetermined, for example, by an impression tool, as used in plastic injection technology.

In further embodiments of the present invention, contacting a liquid hardenable material component selectively on the component, i. h., only a selected part of the component is coated with the hardenable material.

A further advantage of the present invention is that a composite component with an adhesive bond of a component can be made to a sheath of the component made of hardenable material, in which only a part of the component is enclosed with curable material.

Embodiments of the present invention will be explained in more detail below. Show it:

1 a flowchart according to an embodiment of the present invention;

2a a schematic representation of a device according to an embodiment of the present invention;

2 B a schematic representation of a device for providing a component or a portion of a component with an adhesive layer, the part of in 2a shown device; and

3 a sectional view of a composite component according to an embodiment of the present invention.

1 shows a flowchart 100 according to an embodiment of the present invention. The flowchart 100 includes a first step 110 the provision of a component or a Part of a component with an adhesive layer having a micro-rough surface with undercuts, wherein the undercuts are designed to be backed by a liquid curable material. Furthermore, the flowchart includes 100 one step 120 contacting the microrough surface with the liquid curable material such that the liquid curable material overflows the undercuts. Furthermore, the flowchart 100 one step 130 curing the curable material.

The curable material may preferably be a thermoplastic or a thermoplastic elastomer and is therefore also referred to below as a thermoplastic.

The step 110 the provision of a component or a subregion of a component with an adhesive layer can take place, for example, by chemical or electrochemical deposition of an adhesive layer (so-called treatment layer).

The component is here preferably a metal part and is therefore referred to below as a metal part or metal component.

At the in 1 shown method 100 Among other things, all metal components are suitable which have a surface on which an adhesive layer ("treatment layer") can be produced by means of chemical or electrochemical deposition. The adhesive layer (the "treatment") on the metal parts can be deposited, for example, electrochemically by means of the method of "pulse plating" already described, by the parts, ie the metal parts, for example in an acidic copper electrolyte, either individually in the frame or in a drum or Similar to a strip electroplating on a strip from roll to roll are processed. In other words, the metal parts are immersed in a bath of copper electrolytes, wherein the metal parts act as a cathode and, for example, a copper electrode acts as an anode. The pulse regime, ie the properties of the applied current between the anode and cathode, such as pulse height, pulse length and pulse spacing, is selected such that an adherent and smear-resistant adhesive layer ("treatment layer"), for example of copper dendrites, is deposited on all sides on the metal parts. The all-over adhesion coating ("treatment coating") is ensured by a corresponding arrangement of the anodes. The term on all sides is to be understood here merely as an example and not restricting, since in further embodiments it may also be possible that by appropriate design of the anode geometry and coverage of the cathode, the adhesive coating ("treatment coating") is also selective.

Furthermore, it should be mentioned that in further embodiments, instead of the metal part, a ceramic component or another, for example non-conductive component can be used in which an adhesive layer ("treatment layer") either directly on the surface or on an intermediate layer on the surface of chemical or was deposited electrochemically.

Furthermore, in further embodiments of the invention, the component could be provided with an adhesive layer with a micro-rough surface with undercuts, for example by purely chemical processes such as acid etching or the like, or by purely mechanical processes such as grinding, milling or the like. Of course, other embodiments can be used in which the component can be provided with an adhesive layer with a micro-rough surface with undercuts by other, not shown here processes.

The in step 110 The adhesive layer ("treatment layer") produced on the component and its micro-rough surface can be used, for example, in a further step of the method 100 be improved by another chemical treatment, such as oxidation, in their properties, for example in terms of strength, temperature resistance, resistance to external influences or substances, or the like.

The step 120 contacting the microrough surface with the liquid curable material may be accomplished, for example, by overmolding the metal part with a liquid thermoplastic. By the step 110 subsequent overmolding 120 The pretreated metal parts with thermoplastic materials can thus be a form-locking clawing between the two materials, ie the metal part and the thermoplastic, which appears macroscopically as a cohesive connection appears. The thermoplastic may be, for example, a melt-shaped thermoplastic or a plastic melt made of thermoplastic, which connects form-fitting with the microrough surface of the adhesive layer ("treatment layer") during encapsulation of the metal part. Thus, in particular a media- and pressure-tight connection of a thermoplastic, so the curable material and a metal part, ie the component can be achieved.

In contrast to a lamination or hot stamping process, the metal part is heated by the plastic melt in the molding of the metal part with a plastic melt.

That in the step 120 described contacting the microrough surface with a liquid curable material may be equated with imparting to the microrough surface a liquid curable material, providing the microrough surface with a liquid curable material, feeding the microrough surface of a curable material, and then overmolding the microrough surface with a liquid hardenable material, with a back-molding of the microrough surface with a liquid curable material, with immersion of the microrough surface in liquid curable material, such as a plastic melt or with a flow around the microrough surface with a liquid curable material.

The described contacting can take place here under high pressure so as to produce an even better connection of the liquid curable material, that is, for example, the thermoplastic with the microrough surface of the adhesive layer of the component, that is, for example, of the metal part.

The curing 130 the curable material, so for example of the thermoplastic, can be done by cooling the curable material.

Although in the above embodiment, the liquid curable material is formed as a thermoplastic or a thermoplastic elastomer, it may also be possible in other embodiments that the liquid curable material is a thermoset or a UV polymer. It should be noted that when using a UV polymer as a liquid curable material curing does not take place by cooling, but by irradiation of the liquid curable material with UV light. The irradiation, for example in the step 130 This can optionally selectively or flood-like over the entire composite component, so as to allow selective curing and thus a selective coating of the component.

2a shows a device 200 according to an embodiment of the present invention. The device 200 comprises means for providing a component or portion of a component with an adhesive layer having a microrough surface with undercuts, the undercuts being adapted to be backed by a liquid curable material. Furthermore, the device comprises 200 An institution 220 for contacting the microrough surface with the liquid curable material so that the liquid curable material flows behind the undercuts. Furthermore, the in 2a shown device 200 An institution 230 for curing the curable material.

The device 210 for providing a component or a portion of a component with an adhesive layer is formed, for example, a step 110 as he is in the flow chart 100 in 1 has been described. The device 220 for contacting the microrough surface with the liquid curable material is formed, for example, a step 120 as he is in the in 1 shown flow chart 100 has been described. The device 230 for curing the curable material is formed, for example, a step 130 as he is in the in 1 shown flow chart 100 has been described.

2 B shows a schematic representation of the device 210 for providing a component or a portion of a component with an adhesive layer forming part of 2a shown device 200 is.

The device 210 can, for example, a galvanic bath 240 , with a solution of acid copper electrolytes and an anode or an anode arrangement 250 have, in which the components to be coated 260 be processed as a cathode either individually in the frame or in a drum or similar to a strip electroplating on a strip from roll to roll. By applying a voltage, for example a DC voltage or a pulsed voltage, between the anode and the anode arrangement 250 and the cathode, so the components to be coated 260 , positively charged copper ions are deposited on the components to be coated 260 at. As a result, on the components to be coated 260 Copper deposited.

The device 220 For example, it may comprise a plastic melt which is brought into contact with a component coated with an adhesive layer having a microrough surface having undercuts. The bringing into contact can take place here, for example, by immersing the component coated with an adhesive layer in the plastic melt or by encapsulating, injecting or injecting the component coated with an adhesive layer with the plastic melt or else by other similar methods. The device 220 For example, comparable to a plastic injection molding machine may have a tool for generating the shape of the composite component to be produced.

The device 230 For hardening the curable material may include, for example, a cooling chamber for cooling the curable material or when using a UV polymer as a curable material, a UV irradiator, which cures the UV polymer.

3 shows a composite component 300 according to an embodiment of the present invention. The composite component 300 can be based on the in 1 shown method 100 with a device 200 have been produced. The composite component 300 includes a first component 310 For example, a metal component which has an adhesive layer on a surface 320 with a microrough surface with undercuts 330 having. The microrough surface of the adhesive layer 330 is enclosed with hardened hardenable material 340 For example, a cooled thermoplastic.

The microrough surface and the undercuts 330 are shown greatly enlarged here for clarity. The undercuts 330 , which are generated for example by deposited copper dendrites, typically have a height of 3 microns to 100 microns.

It is clearly recognizable in 3 the cauliflower microrough surface of the adhesive layer 320 and the undercuts produced by the cauliflower-like shape of the surface 330 , The cured material 340 has these undercuts 330 flows behind and thus forms a firmly adhering connection to the component 310 , The cured material 340 thus has adherence to the microrough surface of the adhesive layer 320 digs. Furthermore, it can be clearly seen that the micro-rough surface has an enlarged surface in relation to a surface of the component 310 which is in addition to the undercuts 330 due to adhesion forces in a still increased adhesion of the cured material to the component 310 results.

Furthermore, in 3 to recognize that the adhesive layer 320 only over a partial area of the surface of the component 310 extends. It is of course also possible that the adhesive layer 320 the component 310 completely encloses to a complete enclosure of the component 310 with hardenable material 340 to enable.

This in 3 shown composite component 300 For example, it may be an adhesive-coated ("treatment-coated") stamped grid which is overmoulded with a technical or high-performance thermoplastic 340 such as polyamide, polybutylene terephthalate, polyphenylene sulfide or liquid crystal polymer. Furthermore, the composite component 300 an adhesive-coated ("treatment-coated") male contact with an overmolded engineering or high performance thermoplastic 340 such as polyamide, polybutylene terephthalate, polyphenylene sulfide or liquid crystal polymer.

In further embodiments of the present invention, the component 310 For example, a stamped grid, a plug, a vessel, a conduit element or a mechanical element.

Other embodiments of the present invention may provide a method of adhering metallic components to a thermoplastic or thermoset, wherein the surface of the metal component is chemically sealed at least in areas where metal and thermoplastic contact occurs prior to an overmolding process or electrochemically produced adhesive layer ("treatment layer"), which is similar to that provided in the hot stamping foils of the prior art. This adhesive layer ("treatment layer") may optionally by another chemical treatment, eg. As oxidation, be improved in their properties.

In further embodiments of the present invention, unlike printed circuit board technology, this may not be a combination with a thermoset material. Furthermore, when the metal component is brought into contact with liquid curable material, that is, for example, during an extrusion coating process, the metal component is heated and pressed by the plastic melt, while in the case of a printed circuit board production after joining prepreg with metal foil, a lamination process with heat input and pressure takes place. Compared to the hot stamping technique, the metal components in methods according to embodiments of the present invention are generally and preferably no films, but three-dimensionally distinct components with significantly greater thickness. Another difference is that the plastic is melted during hot stamping mainly by the hot foil, while in embodiments of the present invention when contacting the component with the curable material, so for example in a Umspritzvorgang the metal part is heated by the plastic melt ,

In summary, it can be stated that the electrochemical production of an adhesion-promoting microrough layer ("treatment") on metal parts to be extrusion-coated with thermoplastics has hitherto not been used. So far, electrochemically adhesion-promoting adhesive layers ("treatment layers") were deposited only on metal foils, such as copper foils, which were processed from roll to roll. These films have so far only been used in printed circuit board technology and hot stamping MID technology.

Other exemplary embodiments of the present invention may also include a coated with an adhesive layer ("treatment-coated") metal foil (for example, copper foil), which on the adhesive layer side ("treatment side") behind a molten thermoplastic, ie liquid curable material, so brought into contact becomes. This also results in a positive and very adherent connection between the metal foil and the back-injected thermoplastic. This effect is now also utilized in the overmolding of adhesive-coated ("treatment-coated") metal parts with thermoplastics.

Although some aspects have been described in the context of a device, it will be understood that these aspects also constitute a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device.

Claims (17)

Procedure ( 100 ) for producing a composite component comprising the following steps: 110 ) of a component ( 260 ; 310 ) or a subsection of a component ( 260 ; 310 ) with an adhesive layer ( 320 ), which has a microrough surface with undercuts ( 330 ), wherein the undercuts ( 330 ) are designed to receive a liquid curable material ( 340 ) to be drowned; and bringing in contact ( 120 ) of the microrough surfaces with the liquid curable material ( 340 ), so that the liquid curable material ( 340 ) the undercuts ( 330 ) flows behind. Procedure ( 100 ) according to claim 1, wherein the microrough surface is coated with the liquid hardenable material ( 340 ) is sprayed or circulated around the microrough surface with the liquid curable material ( 340 ). Procedure ( 100 ) according to claim 1 or 2, further comprising the step of: curing ( 130 ) of the liquid curable material ( 340 ). Procedure ( 100 ) according to one of claims 1 to 3, wherein the liquid curable material ( 340 ) is a plastic melt and in which the microrough surface is brought into contact with the plastic melt; and wherein the plastic melt is designed to transfer heat to the component ( 260 ; 310 ). Procedure ( 100 ) according to claim 4, wherein the plastic melt is formed from a liquid thermoplastic or a liquid thermoplastic elastomer or a liquid elastomer or a duromer. Procedure ( 100 ) according to one of claims 1 to 5, in which the component ( 260 ; 310 ) by chemical or electrochemical deposition with the adhesive layer ( 320 ). Procedure ( 100 ) according to claim 6, wherein the chemical or electrochemical deposition for providing the component ( 260 ; 310 ) with an adhesive layer ( 320 ), immersing a drum or rack with at least one component ( 260 ; 310 ) in a chemical or electrochemical bath ( 240 ), or passing through a belt with at least one component ( 260 ; 310 ) by a chemical or electrochemical bath ( 240 ). Procedure ( 100 ) according to one of claims 1 to 7, in which the bringing into contact ( 120 ) of the microrough surface with the liquid hardenable material ( 340 ) under pressure. Procedure ( 100 ) according to one of claims 1 to 8, in which the component ( 260 ; 310 ) Metal. Procedure ( 100 ) according to one of claims 1 to 8, in which the component ( 260 ; 310 ) comprises an electrically non-conductive material, and further comprising the step of: applying an electrically conductive layer to the component ( 260 ; 310 ) or a portion of the component ( 260 ; 310 ). Procedure ( 100 ) according to claim 10, wherein the electrically non-conductive material is ceramic. Procedure ( 100 ) according to one of claims 1 to 11, in which the component ( 260 ; 310 ) is a punched grid or a plug or a vessel or a conduit element or a mechanical element. Procedure ( 100 ) according to one of claims 1 to 12, further comprising the following step: oxidation of the microrough surface of the adhesive layer ( 320 ). Contraption ( 200 ) for producing a composite component, comprising: a device ( 210 ) for providing a component ( 260 ; 310 ) or a subsection of a component ( 260 ; 310 ) with an adhesive layer ( 320 ), which has a microrough surface with undercuts ( 330 ), wherein the undercuts ( 330 ) are designed order from a liquid curable material ( 340 ) to be drowned; and a facility ( 220 ) for contacting the microrough surface with the liquid curable material ( 340 ), so that the liquid curable material ( 340 ) the undercuts ( 330 ) can flow behind. Contraption ( 200 ) according to claim 14, wherein the device ( 210 ) for providing the component ( 260 ; 310 ) or a portion of the component ( 260 ; 310 ) with the adhesive layer ( 320 ) an anode arrangement ( 250 ), which is formed to the component ( 260 ; 310 ) or a portion of the component ( 260 ; 310 ) by electrochemical deposition selectively or completely with the adhesive layer ( 320 ) to provide Contraption ( 200 ) according to claim 14 or 15, wherein the component ( 260 ; 310 ) is an extended 3-dimensional rigid body and has a curved surface; and where the device ( 210 ) for providing the component ( 260 ; 310 ) or a portion of the component ( 260 ; 310 ) with the adhesive layer ( 320 ) is formed to completely or at least partially with the adhesive layer ( 320 ) to provide. Composite component ( 300 ), comprising: a component ( 260 ; 310 ), wherein the component ( 260 ; 310 ) or a part of the component ( 260 ; 310 ) with an adhesive layer ( 320 ), which has a micro-rough surface with undercuts ( 330 ) having; and a cured material ( 340 ) attached to the component ( 260 ; 310 ) and which contacts the microrough surface in such a way that the hardened material ( 340 ) the undercuts ( 330 ) to ensure a strong bond between the cured material ( 340 ) and the adhesive layer ( 320 ) to create.

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