Electrical contacting of a conductive film, especially a heating layer for laminated automobile glazing, comprises connecting a collector bar to solder deposits by energy supply through the pane and-or an adhesive film on the thin film

The invention relates to a method for electrically contacting a leit capable thin film on a glass sheet.

Such a process is basically known from EP 0527680 B1 and the supplied impaired German translation DE 692 01 930 T2.

The composite glass panel described therein comprises a first glass sheet having a layers deposited thereon sequence z of an electrically conductive heating layer. B. simplified silver and these enclosing antireflection (hereinafter referred to as Thin film hereinafter). At the edge of the glass sheet by the process described there, Manufacturing process before application of the thin film on the glass surface a strip coated from Leitsilberpaste and baked. Above this strip is to the application of the thin film aufgetra a solder layer with ultrasonic support gen. The application of ultrasound to the breaching of the poorly or not lei border anti-reflective coatings, so that the solder direct in sufficiently Contact with the conductive (silver) can reach layer. With the solder layer is a thin copper sheet as a current bus bar by soldering at least at a plurality connected by points. On the copper strip finally is a power connection cable to closable.

After completion of this Kontaktierungsmaßnahmen the laminated glass is in the conventional manner by placing an adhesive film of polyvinyl butyral (PVB) and the completes second glass plate, evacuated and laminated in an autoclave. The search for this Process products obtained have proved themselves in practice, but will only individual solder deposits ultrasonically assisted soldered. When was exported slices no conductive silver strips between glass and thin film provided, but only a opaque edge strip.

In laminated glass embedded thin-film systems are usually caused by Cathode produced in a vacuum (sputtering) and are compared with pyro lytically deposited thin films are relatively sensitive to mechanical Einwirkun gen. It therefore aims at the time and machining operations between the Abschei to minimize the layer system and the production of the composite.

British Patent 1,183,316 discloses a method for producing a through resistance wires heatable laminated pane. Thus you can the entire first Composite structure made from two sheets of glass with inlaid heating wires, pre-tinned Sam busbars and adhesive film finish in the autoclave. It is then fed through the Glass panes through energy for melting the pre-tinning and preparing the electrically connecting to between the bus bars and the heating wires, by a system suitable for high-frequency induction tool along the busbars to be led. It is not intended and with the disclosed tool not possible, the energy with only locally at the respective contact points of the bus bars feeding the individual wires.

It is also known (DE-AS 18 07 862), busbars specifi detail of a there ed solder with ultrasound support directly on a glass surface of a solder heated single pane of glass. The ultrasonic vibrations to the improve access of Speziallots to the glass surface. The busbars may also be divided into sections, occurs to reduce the manufacturing cost of the Location of an applied by screen printing a conductive strip Leitsilberpaste. The Heating itself is formed by resistance strips and by screen printing Baking a conductive paste are prepared.

Lote for direct soldering to glass and other substrates are also poorly solderable otherwise known in manifold versions.

Finally, DE 22 27 238 A1 discloses a heatable single glass pane with rand side metallization and it deposited metal or metal layer whose connections to the outside by soldering electrical conductors to the Metallization zones are produced. The metal or metal oxide layer is applied to the Pads mechanically removed prior to soldering to the required electrical and optical characteristics of the connection ensured.

U.S. Patent 5,332,888 describes, inter alia, a laminated glass windshield with built-in solar filter made of silver layers, the electric by applying tension tion can be used as heatable layers. Must the Dünnschich th busbars are used having a relatively rough surface whose Unebenhei th penetrate during lamination in the thin films and therefore a good electrical can make contact.

The invention is based on the object, a method of the type mentioned with regard to the inclusion in the production line to further improve and to reduce risk of damage to the thin film.

This object is achieved with the features of claim 1. The features of the subclaims specify advantageous developments of this method at.

The laid on the thin film in a predetermined position busbar (they will preferably made of a thin, pre-tinned copper strip) is only after the durchdrin placing the adhesive film by means of a glass pane and / or the adhesive sheet verlö lowing power supply with the arranged beneath the thin solder deposits tet, wherein the thin film is broken at least partially to the solder joints. The method is both networks of a single pane of glass and an adhesive film as well as the usual in particular for vehicle glazing composite structure th applicable with at least two glass sheets and these connecting adhesive film. in the the latter case, the energy can also be supplied by the second glass sheet. For the application of the inventive method is not a second sheet of glass absolutely necessary.

With the above measures, we achieved a strong shortening of Manipulation duration of the glass pane with an exposed film. After their application is placed and positioned only the busbar - possibly also temporarily fixed, z. For example by adhesive dots -, immediately thereafter, the adhesive film and possibly the second Glass pane placed. Soldering with exposed film and related extensive damage risks are completely eliminated.

Also scored one a very reliable electrical contact of the thin film, for which at least local soldering of the contact means with the help of ultrasound before Applying the thin layer directly on the glass or on a frit fixed Base is. In good, the contact points are defined by templates.

In a particularly preferred formation is prior to the power supply the trapped Air removed from the composite, but not yet for füh Vorverbinden the laminate Rende supplied heat. It is particularly advantageous for the contact safety finally, if at least during the power supply, a pressure or pressure forces on the Lötstel len be exercised. These forces result from the preferred removing the air the composite of the influence of the ambient pressure on the outer glass panes areas. However, the contact forces could also purely mechanically without vacuum effect be generated.

required for supplying for soldering the bus bar to the contact points Energy are in principle several options into consideration, in particular, was High-frequency induction calculated as the appropriate method. You can see the locally required Energy but also by heat radiation (infrared) of the not ver with the thin film provided side or out by laser beams.

In general, the energy may be continuous with a sweep of the areas to be soldered or be selectively supplied by selective heating of the contact or solder points. The energy input should be metered so that the adhesive film it still possible is not plastically deformed.

You can see the contact points without affecting the one in question electrical Connection instead of directly onto the glass surface on an opaque frit set, which is usually required for covering the electrical connection elements. As Secondary advantage of the method discussed here you recognize any weaknesses in Screen printing edge immediately after the ultrasonic soldering even before the application of the Thin.

After soldering, the so far only preliminary collapsed and possibly evaku ated laminated glass in the usual way a Vorverbindeprozeß with increased fed temperature and finally under high pressure and temperature of the melt Adhesive film laminated to the finished product.

Laminated glass panes with contacted by the process described Dünnschich th can be used in particular as full-surface heatable disks. however can also find other uses the conductive thin film, eg. as in formants nenscheiben or solar modules.

Further details and advantages of the subject matter of the invention emerge from the drawing tion of an embodiment and their detailed in the following subsequent the description.

The sole Figure is a schematic and not to scale, sectional view of a Laminated glass pane in the embodiment according to the inventive method. These consists essentially of a first lower sheet of glass <b>1</b>, An adhesive film <b>2</b> and a second, upper glass pane <b>3</b>, Can also be seen in the section of the near-edge Be Reich the first glass pane <b>1</b> a parallel to the edge extending edge streak <b>4</b>, The opaque edge strip<b>4</b> consists of an advance by sieve printing on the glass sheet <b>1</b> applied and baked ceramic or enamel color, which can also be electrically conductive. Such margins are known to the edge in particular provided by vehicle glass panes electric Kon covering contacts and adhesive strands visually and if necessary to protect against UV radiation.

On the edge strips <b>4</b> can be seen in section, a solder deposit <b>5</b>, This is one of a whole range of non-visible here like solder deposits, which laid in a added assembly and preferably using a template along the Randstrei fen were applied. You are in a conventional manner with ultrasound sup tion soldered. This is a mechanically resilient contact with its substrate ensured. For this purpose one uses a suitable metallic solder or Contact means. One could just as well the solder deposits resolu directly on the glass surface th when either no edge strip is required or otherwise for a corre sufficient visual coverage is provided (eg. as in another of the four glass disc surfaces of the laminated glass pane). For the discussed herein, the edge strip itself irrelevant.

After the production of the solder deposits <b>5</b> A transparent layer sequence of min least one electrically conductive heating layer z. B. in silver and enclosing this Antireflection surface on the glass pane <b>1</b> applied, preferably to sputtered. It is here simply as uniform thin film<b>6</b> designated and Darge provides. Your can be added as needed, further layers. Obviously over covers the thin film <b>6</b> both the marginal strip <b>4</b> and the solder deposit <b>5</b> and Furthermore, invisible solder deposits.

There are other appropriate measures to protect the thin film <b>6</b> against Korro sion ago taken from the edge of the laminated glass pane, the Mannig in the art times are described.

The film, firstly a passive thermal barrier function against Infrarotstrah have treatment, on the other hand it has in the present case also active electrical function. It is in particular as a heating layer for heating an area of ​​the laminated glass pane used. With a suitable structure and appropriate design of the electrical rule connections they may also serve as an antenna pane.

Above the solder deposits <b>5</b> is for electrically contacting the thin film <b>6</b> after outside a busbar <b>7</b> provided. This preferably consists of a narrow, thin copper sheet, which in turn is coated with a thin layer of solder. The busbar <b>7</b> if you wish, not visible here, not brushing Adhesives on the film <b>6</b> be temporarily fixed. Moreover, it is in itself known manner connected with - electrical connection means - not shown the laminated glass pane are led out.

In preparing the laminated glass pane is immediately after hanging up, positioning and possibly fix the busbar <b>7</b> the adhesive film <b>2</b> carefully placed and positio defined so that the thin film <b>6</b> is covered. Then, the composite structure with the second glass plate <b>3</b> completed. In this manufacturing stage, the drawn direct contact between the busbar <b>7</b> and the solder deposit <b>5</b> according to the method presented here is not prepared. Rather, the film still forms a continuous separating interlayer.

The solder deposits <b>5</b> Namely, with the lowest possible elevation above the glass pane or edge strip surface produced. In any case, they are however - like the edge streak <b>4</b> and the busbar <b>7</b> - Substantially thicker than the thin film <b>6</b>That norma mally only a few nanometers to micrometers thick and here the visibility sake was drawn with exaggerated thickness.

The solder deposits <b>5</b> may have a relatively rough surface due to the ultrasonic action who whose tips the film without further assistance in their preparation by can penetrate. To produce the necessary intimate electrical contact between the busbar <b>7</b> and the thin film <b>6</b> will now be through the glass panes <b>1</b> and/ fed or 3 through energy which the pre-tinning the busbar <b>7</b> so as the material of the solder deposits can be melted. Preferably used High-frequency induction. Suitably not lead to the energy continuously over the entire length of the bus bar, but only at the locations of the solder deposits (about to the position indicated by dashed circles joints). This process can as a result of predetermined positions of the solder deposits also mechanize very good - this especially in the use of laser energy - and ideally in a line clock incorporate in the series production of laminated glass panes. The aforementioned adhesive provisionally fixing the busbar <b>7</b> be expedient in between the solder deposits lying attached intervals. They can in principle before applying the busbar may be stuck to the thin film, it is preferred, however, the busbar itself preliminary set accordingly.

The film is in the melting of the low melting metals locally broken, so that the indicated direct connection between the solder deposit <b>5</b> and the busbar <b>7</b> results. The conductive layer of the thin film is likewise with the busbar <b>7</b> electrically connected. Through experiments was a high Reproducibility are verified with low contact resistance.

The best results are obtained if, prior to the energy supply the trapped Air is evacuated from the composite structure (eg., By use of a Absaugrah volume) and during energy supply pressure is exerted on the pane edges. in the Case sufficient applied negative pressure to the ambient pressure on the glass panes benflächen forces exerted.