CN114364530A

CN114364530A - Method for electrically contacting a planar electrode of a functional element having electrically controllable optical properties

Info

Publication number: CN114364530A
Application number: CN202180003187.9A
Authority: CN
Inventors: A·费赛马兹; S·特拉巴门德斯; N·黑克; 张慧星
Original assignee: Saint Gobain Glass France SAS
Current assignee: Saint Gobain Glass France SAS
Priority date: 2020-08-06
Filing date: 2021-07-22
Publication date: 2022-04-15
Also published as: WO2022028903A1

Abstract

The invention relates to a method for electrically contacting planar electrodes (2, 4) of a functional element (100, 100') having electrically controllable optical properties, said functional element comprising, arranged one above the other: -a first carrier film (1), -a first planar electrode (2), -an active layer (3), -a second planar electrode (4) and-a second carrier film (5), wherein a) the first carrier film (1) is cut into by means of a perpendicular laser beam (7) such that the first carrier film (1) is divided into a segment (8) to be separated and a remaining main part (9), b) the segment (8) of the carrier film (1) is removed together with the first planar electrode (2) arranged in the region of the segment (8) and at least partially with the active layer (3) arranged in the region of the segment (8) such that the first carrier film (1) and the first planar electrode (2) form a common edge, c) the second planar electrode (4) is cleaned, in that the active layer (3) is completely removed in the region of the removed segment (8) such that the exposed horizontal surfaces of the planar electrodes (4) are exposed, and d) the second planar electrode (4) is electrically contacted at the exposed surfaces.

Description

Method for electrically contacting a planar electrode of a functional element having electrically controllable optical properties

Technical Field

The invention relates to a method for electrically contacting a planar electrode of a functional element having electrically controllable optical properties.

Background

Functional elements with electrically controllable optical properties are used in the industrial production of glazing units (Verglasungseinheiten). Such glazing units are typically composite sheets into which the functional elements are embedded. The composite panel consists of at least one outer panel, an inner panel and an adhesive intermediate layer which connects the outer panel to the inner panel in a planar manner. In manufacturing the composite board, functional elements are cut out in a desired size and shape with the multilayer films, and the functional elements are inserted between the films of the intermediate layer. Typical interlayers here are polyvinyl butyral films which, in addition to their adhesive properties, also have high toughness and high acoustic damping. The interlayer prevents the composite glass sheet from collapsing when damaged. The composite panel only cracks but remains dimensionally stable.

Composite plates with electrically controllable optical properties are known from the prior art. Such composite plates contain a functional element, typically comprising an active layer between two planar electrodes. The optical properties of the active layer can be changed by a voltage applied to the planar electrode. Examples of this are electrochromic functional elements, which are known, for example, from US 20120026573 a1 and WO 2012007334 a 1. Another example is an SPD function (Suspended particle Device) or a PDLC function (Polymer Dispersed Liquid Crystal), which are known for example from EP 0876608B 1 and WO 2011033313 a 1. The transmission of visible light through the electrochromic or SPD/PDLC functional element can be controlled by the applied voltage.

SPDs and PDLC functional elements are commercially available as multilayer films. The planar electrodes required for applying the voltage are arranged between two PET carrier films. In the manufacture of glazing units, functional elements are cut from multiple layers of film and inserted between the films of an interlayer. The planar electrode can be electrically conductively connected to a control module (ECU) outside the composite plate via a flat conductor. The control module is configured to apply a voltage between the planar electrodes.

A possible adjustable functional element for realizing an adjustable sun visor is known from WO 2017/157626 a 1. The functional element is divided into segments by insulated wires. The insulating wire is introduced in particular into the planar electrodes of the functional element, so that the segments of the planar electrodes are electrically insulated from one another.

In WO 2020/083562 a1 and WO 2020/083563 a1, composite panels with a segmented switchable functional element are proposed.

WO 2020/143984 a1 discloses an unmounted functional element with electrically controllable optical properties, which comprises a protective film and a sealing film.

WO 2019/238520 a1 discloses a functional element with electrically controllable optical properties, in which a first carrier film is folded around the edge of a second carrier film at one side edge and the exit face of the active layer is sealed at this side edge.

Since each segment must be electrically contacted individually, the electrical contacting is a difficult step in the production of composite plates with functional elements divided into a plurality of segments. This is usually achieved by means of suitable connecting cables, for example, film conductors, which are connected to the planar electrodes via so-called bus conductors (bus bars), for example strips of electrically conductive material, or conductive prints (for example constructed from silver-containing screen-printed matter). The contacting is performed manually step by step and comprises a number of working steps. This action is very time consuming.

Disclosure of Invention

The object of the present invention is to provide an improved method which allows a reduction in the time required for electrically contacting functional elements and a great freedom in the choice of the position of the contact.

The object of the invention is achieved according to the invention by a method according to independent claim 1. Preferred embodiments of the invention emerge from the dependent claims.

The invention comprises a method for electrically contacting a planar electrode of a functional element having electrically controllable optical properties, wherein the functional element has a first carrier film, a first planar electrode, an active layer, a second planar electrode and a second carrier film, arranged one above the other.

The method according to the invention comprises at least the following steps:

a) cutting into the first carrier film by means of a perpendicular laser beam, so that the carrier film is divided into segments to be separated and remaining main portions,

b) removing the segments of the carrier film together with the first planar electrode arranged in (below) the segmented regions and at least partially with the active layer arranged in (below) the segmented regions, such that the first carrier film and the first planar electrode constitute a common edge,

c) cleaning the second planar electrode by completely removing the active layer in the removed segmented regions such that the exposed horizontal surfaces of the planar electrode are exposed, and

d) electrically contacting the second planar electrode at the exposed surface.

The method according to the invention has the advantages that: the incision into the carrier film is not performed manually (without manual incision with a sharp object). By using a laser in step a), the effort required for producing the contact surfaces is reduced and thereby valuable work time is saved in the production of functional elements having electrical contacts. Cutting the first carrier film by means of a laser can be carried out automatically. Therefore, the method is very advantageous especially for industrial mass production.

Furthermore, the possibility of selectively cutting the carrier film using a laser is advantageously provided. Thus, the coated carrier film (also referred to as substrate layer) can be easily removed. By using a laser it is possible to cut the carrier film quickly and simply at arbitrary positions or in arbitrary shapes, depending on the design.

The functional element comprises at least one active layer arranged between a first carrier film and a second carrier film. The active layer has variable optical properties that can be controlled by a voltage applied to the active layer. Electrically controllable optical properties are understood to be such properties that are continuously controllable in the sense of the present invention, but equally such properties that can be switched between two or more discrete states. The optical properties relate in particular to the light transmission and/or scattering behavior.

The functional element furthermore comprises a first carrier film and a second carrier film. The first and second carrier films are in particular polymer or thermoplastic films. The first and second carrier films may be the same or different in their composition and/or thickness. The two carrier films are typically composed of the same composition. The following description of the carrier film refers not only to the first carrier film but also to the second carrier film.

In particular, the carrier film comprises or consists of a thermoplastic material. The thermoplastic material may be a thermoplastic polymer or a mixture of two or more thermoplastic polymers. In addition to the thermoplastic material, the carrier film may furthermore contain additives, such as plasticizers. The thermoplastic material of the carrier film is preferably polyethylene terephthalate (PET) as is common for commercially available functional elements.

The thermoplastic material of the carrier film may also comprise or consist of a mixture of PET with other thermoplastic polymers and/or a copolymer of PET. The thermoplastic material of the carrier film may also comprise or consist of PU, polypropylene, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinyl chloride, polyacetate resins, fluorinated ethylene-propylene, polyvinyl fluoride and/or ethylene-tetrafluoroethylene, for example. The thickness of each carrier film is preferably in the range of 0.03 mm to 0.4 mm, more preferably 0.04 mm to 0.2 mm.

The functional element furthermore comprises a planar electrode for applying a voltage to the active layer, which is preferably arranged between the carrier film and the active layer. The planar electrodes are typically constructed in the form of a conductive coating on a carrier film. The side of the carrier film having the electrically conductive coating forming the planar electrode then faces the active layer. The planar electrodes may be the same or different in their composition and/or thickness. The planar electrodes are mostly identical.

The idea of the invention is to cut the first carrier film in a manner that is pitted (schonende) by process step a) in such a way that smooth cut edges are formed without disturbing damage (Schnittkanten). By using a laser beam, the carrier film can be cut into at every position on its surface. The method can realize free shaping of the contact surface.

In principle, the segment can be removed simultaneously with or after cutting the first carrier film. The chronological order of the method steps a) and b) should not be understood as meaning that the laser irradiation along the entire cutting line has to be completed before the removal of the segments begins. Conversely, during the movement of the laser beam still over the cutting line, it is already possible to start removing the region of the cutting line that has been separated by the laser beam. The segments may in principle have any shape and size. The segments can be of angular, elliptical or circular, in particular quadrangular, configuration. The segments may preferably extend in the form of strips along the side edges of the functional element. In addition, in step a), the main part can completely surround the segment in the layer of the first carrier film.

In a preferred embodiment, the segments are removed after cutting the first carrier film. The removal of the segments from the main part of the first carrier film is performed by means of a suction device, in particular a suction cup. Here, the suction device is placed in the segmented region on the first surface of the first carrier film. In the sense of the present invention, the first surface of the first carrier film is referred to as that surface of the first carrier film which faces away from the first planar electrode.

The irradiation with the laser is preferably carried out from the direction toward the first surface, so that the laser beam does not have to penetrate the functional element before impinging on the first surface of the first carrier film. In other words, the laser beam is focused on the first surface of the first carrier film.

In an advantageous embodiment, a deflection unit can be provided for deflecting the laser beam. The diverting unit is arranged for diverting the laser beam over the first carrier film such that a segment is cut into the carrier film to remove the segment of the carrier film. The steering unit may have a scanner or an X-Y coordinate system. So that any shape of the segments can be laser machined (lasern) into the carrier film. The scanning speed or coordinate system speed may be from 0.1 m/s to 20 m/s, preferably from 0.5 m/s to 10 m/s, particularly preferably from 2 m/s to 5 m/s (meters per second).

The subsequent removal of the segments results in an exposed surface of the second planar electrode, since at the same time the first planar electrode and the partially active layer adhere to the segments in the region of the segments and are removed. The exposed surface of the second planar electrode is cleaned by means of a laser beam and/or a cleaning agent, in particular acetone, and is removed from the remaining part of the active layer in the region exposed by the segment. The shape and size of the exposed surface corresponds to the shape and size of the removed segments of the first carrier film. The second planar electrode is electrically contacted at an exposed surface of the second planar electrode.

The planar electrode is arranged for electrical connection to an external voltage source. The planar electrodes are preferably contacted by (ultrasonic) welding, crimping (vercrimppen) or gluing. For this purpose, in step d) an electrically conductive material, in particular a paste or solder contact, is applied to at least one of the planar electrodes. The paste comprises silver or a silver-containing alloy. The electrically conductive material is connected to the planar electrodes as so-called bus conductors (bus bars), for example strips or conductive imprints of electrically conductive material. The planar electrodes can each be electrically contacted by means of a bus conductor.

In an alternative embodiment of the busbar, thin, narrow metal foil strips or wires are used, which preferably contain copper and/or aluminum, in particular copper foil strips having a thickness of approximately 50 μm. The width of the copper thin film strip is preferably 1 mm to 10 mm. The metal foil strips or wires are applied to the planar electrode during the further processing of the functional elements in the composite body consisting of the thermoplastic layers. In a later autoclaving process, a safe electrical contact between the busbar and the cladding is achieved by the action of heat and pressure. The electrical contact between the planar electrode and the bus conductor may alternatively be established by soldering or bonding with a conductive adhesive.

In an advantageous embodiment, the laser beam is formed by CO₂Laser generation. The laser beam has a wavelength of 5 μm to 15 μm, preferably 10.6 μm. The maximum power of the laser is preferably 120W, with a power of about 20W to 50W, preferably 25W, being applied. The laser has not only a pulsed mode of operation but also a continuous wave mode, wherein the pulsed mode is preferred. The pulse length can be 2-400 μm, the pulse sequenceThe frequency is preferably 1000 Hz to 60,000 Hz, particularly preferably 2000 Hz.

The method according to the invention can be carried out at two opposite sides of the functional element, so that the second carrier film is also cut into by means of the laser beam. Similarly to the first film, the second carrier film is here divided into the segments to be separated and the remaining main part. The segment of the second carrier film is removed together with the second planar electrode arranged in the region of the segment and at least partially together with the active layer arranged in the region of the segment, so that the second carrier film and the second planar electrode form a common edge. The face of the first planar electrode is cleaned by completely removing the active layer in the removed segmented areas such that the exposed horizontal surfaces of the first planar electrode are exposed. The first planar electrode is electrically contacted at the exposed surface.

The bus conductor is arranged at the planar electrode in such a way that the carrier film, the planar electrode and the active layer are freed by means of the method according to the invention in such a way that the respective other planar electrode with the associated carrier film protrudes. This may preferably be performed along the edge regions of the respective sides of the functional element. The bus conductors can then be placed on the protruding planar electrodes. On the opposite side of the respective functional element, a further busbar conductor is arranged in a corresponding manner at the further planar electrode.

The bus conductors are electrically conductive. For example, the bus conductor can also be formed by a conductive metal strip or a conductive coating, for example a printed matter containing silver. Here, the metal includes a metal alloy. For example, a belt composed of copper or a copper alloy is also suitable. The bus conductors, which are embodied as metal strips, can be connected to the planar electrodes, typically via an electrically conductive intermediate layer, for example a silver layer.

In a further advantageous embodiment, the functional element can be divided into segments by means of insulated wires. The insulating wire is in particular introduced into the planar electrode such that the segments of the planar electrode are electrically insulated from one another. The individual segments can be connected independently of one another via a connecting region at the busbar, the litz wire, a Crimp connector (Crimp), a wire and/or a flat conductor to an external voltage source, so that they can be individually actuated in the operating state. In this case, the segment of the functional element has two connecting regions. Each connection region has a contact (Kontaktierung) established according to the method according to the invention. Thus, for example, different regions of the functional element can be switched independently, for example as a sun visor.

The insulated wires and the segments are particularly preferably arranged parallel to one another. The insulated wires do not necessarily have to be straight but may also be slightly curved, preferably adapted to the possible curvature of the edges of the composite plate.

In an advantageous embodiment, the functional element is a PDLC functional element, in particular a functional element which switches at least one region of the glazing unit from a transparent state into an opaque state and vice versa. The active layer of the PDLC functional element comprises liquid crystals that are lined in a polymer matrix. In a further preferred embodiment, the functional element is a PNLC or SPD functional element. In the case of an SPD functional element, the active layer contains suspended particles, wherein the absorption of light by the active layer can be altered by applying a voltage to the planar electrodes. PNLC functional elements (PNLC = polymer network liquid crystal) comprise an active layer, in which the liquid crystal is inserted into the polymer network, wherein the mode of action is otherwise similar to that in the case of PDLC functional elements. The thickness of the functional element is, for example, 0.09 mm to 1 mm.

The functional elements may be present as rolls (Rollenware). The roll may then be used to cut pieces of the appropriate size. The faces of the functional elements according to the invention, which are suitably cut, can vary widely and can thus be adapted to the requirements of the individual case.

The planar electrode is preferably configured as a transparent conductive layer. The planar electrode preferably comprises at least one metal, metal alloy or Transparent Conducting Oxide (TCO). The planar electrode may for example comprise silver, gold, copper, nickel, chromium, tungsten, Indium Tin Oxide (ITO), gallium-or aluminium-doped zinc oxide and/or fluorine-or antimony-doped tin oxide. The planar electrode preferably has a thickness of 10 nm (nanometers) to 2 μm (micrometers), particularly preferably 20 nm to 1 μm, very particularly preferably 30 nm to 500 nm.

The invention further comprises a functional element with electrically controllable optical properties, at least in a face-on-face arrangement, comprising:

-a first carrier film having a first carrier film,

-a first planar electrode

-an active layer, which is,

-a second planar electrode, and

-a second carrier film,

characterized by the electrical contact established according to the method of the invention.

The invention furthermore relates to a glazing unit comprising a first pane, a second pane and at least two intermediate layers between the first pane and the second pane, wherein a functional element according to the invention is arranged in a layer between the two intermediate layers.

Drawings

The invention is explained in more detail below with reference to figures and examples. The figures are schematic and not to scale. The drawings are not intended to limit the invention in any way.

Figure 1 shows a schematic view of a functional element as a multilayer film,

figure 2 shows a plan view of a further development of the functional element according to the invention,

FIG. 3 schematically shows an embodiment of the method according to the invention, and

fig. 4 shows a schematic diagram of the functional elements divided into segments.

Detailed Description

The invention will be described more in depth with reference to the following figures. It should be noted here that different aspects are described, which aspects may each be used individually or in combination. That is, each aspect may be used with different embodiments of the invention as long as it is not explicitly shown as a pure alternative.

The description with numerical values is not to be understood as an exact value in each case, but also includes tolerances of +/-1% up to +/-10%.

Fig. 1 schematically shows a multilayer foil 10 in cross-section. The multilayer film 10 can be used as a PDLC functional element 100 having a first carrier film 1, a first planar electrode 2, a PDLC active layer 3, a second planar electrode 4, and a second carrier film 5. The PDLC active layer 3 consists of a polymer matrix arranged between the two planar electrodes 2 and 4, in which liquid crystal droplets are embedded. The planar electrodes 2 and 4 may be transparent ITO coatings. The

carrier films

1 and 5 may each consist of a PET film.

Fig. 2 shows a plan view of a further embodiment of the functional element 100 with the

bus conductors

6a, 6b on both sides of the functional element 100.

Two

bus conductors

6a and 6b are provided for electrically contacting the functional element 100. The

bus conductors

6a and 6b extend as two strips along respective one side of the active layer 3. It goes without saying that the

bus conductors

6a and 6b need not be arranged or need not be arranged only along one side edge of the active layer 3, but may be arranged arbitrarily. The

bus conductors

6a and 6b collect and conduct the current flowing through the planar electrodes 2 and 4.

Bus conductors

6a and 6b are arranged on the

opposite carrier films

1 and 5, respectively. The first bus-conductor 6a is configured as a narrow-edge strip of the second planar electrode 4, while the second bus-conductor 6b is configured as a narrow-edge strip of the first planar electrode 2.

The

bus conductors

6a, 6b are connected to the planar electrodes 2, 4 in such a way that the first carrier film 1, the first planar electrode 2 and the active layer 3 are left free (ausgespark) along the edge regions of the respective sides of the functional element by means of the method according to the invention, so that the second (further) planar electrode with the associated carrier film protrudes. The bus conductor 6a is arranged on the protruding second planar electrode 4. On the opposite side of the functional element 100, a further busbar 6b is arranged in a corresponding manner on the first planar electrode 2.

The

bus conductors

6a and 6b are much thicker than the planar electrodes 2 and 4, so that the true relationship cannot be expressed to scale (Verh ä ltnisse). The

bus conductors

6a and 6b can each be connected to a voltage source via a flat conductor 12, the flat conductor 12 extending from the

bus conductors

6a, 6b over the side of the functional element 100. The flexible flat conductor (sometimes also referred to as a thin film conductor or a flat conductor) preferably consists of a tinned copper tape having a thickness of 0.03 mm to 0.1 mm and a width of 2 mm to 16 mm. Copper has proven to be suitable for such ribbon wire (Leiterbahnen) because of its good electrical conductivity and good handleability as a thin film. Meanwhile, the material cost is low. Other conductive materials that can be processed into thin films can also be used. Examples of this are aluminum, gold, silver or tin and alloys thereof.

In the operating state, the functional element 100 is connected to a voltage source via the two conductive planar electrodes 2 and 4. By means of the switch, the circuit can be closed (ON mode) and opened (OFF mode). In the ON mode (ON or transparent mode), an electric field is applied to the planar electrodes, and thus also to the active layer 3, the liquid crystals of the active layer 3 are aligned in an ordered manner, and the incident light is hardly scattered, which results in a transparent PDLC layer. If the current is switched off (off or opaque mode), the liquid crystals of the active layer 3 are randomly aligned, so that the incident light is scattered and the PDLC active layer 3 becomes opaque or opaque.

Fig. 3 schematically shows an embodiment of the method according to the invention in a vertical longitudinal section of the first carrier film 1 in the edge region of the functional element 100. To clarify the method, fig. 3 shows an intermediate stage in the establishment of the electrical contact of the functional element 100 of fig. 2.

A multilayer film 10, which is illustrated in more detail in figure 1, is used.

a) The first carrier film 1 is cut with a perpendicular laser beam 7 at a distance from the edge of the first carrier film 1 up to the surface of the first planar electrode 2, so that the carrier film 1 is divided into segments 8 to be separated and a remaining main part 9. The segments 8 have a rectangular shape. The laser beam 7 is composed of CO₂Laser generation. The laser beam 7 has a wavelength of 10.6 μm. The power of the laser was 25W. The pulse length can be 2 to 400 mus, and the pulse sequence frequency is 2000 Hz.

b) The segment 8 of the carrier film 1 is removed together with the first planar electrode 2 arranged below the segment 8 in this region. The active layer 3 arranged below the segment 8 in this region is thereby also partially removed, so that the first carrier film 1 and the first planar electrode 2 form a common first edge at a distance from the edge of the second carrier film 5. The segments 8 are removed after cutting the first carrier film 1. The removal of the segments 8 from the main portion 9 of the first carrier film 1 is performed by means of suction cups. Here, the suction cups are placed on the first surface of the first carrier film 1. The first surface of the first carrier film 1 is referred to in the sense of the present invention as that surface of the first carrier film which faces away from the first planar electrode 2.

c) The face of the second planar electrode 4 is cleaned in that the active layer 3 is completely removed in the region of the segments 8, so that the bare horizontal surfaces of the second planar electrode 4 are exposed. The cleaning of the second planar electrode 4 in the region of the removed segment 8 is carried out by means of a laser beam and/or acetone.

d) The second planar electrode 4 has a connection region in the region of the removed segment 8. The planar electrode 4 is electrically conductively connected to the bus conductor 6a in the connection region. The bus conductor 6a has the following tasks: the current is conducted as uniformly as possible into the planar electrode 4. The bus conductor 6a is strip-shaped and/or rectangular and extends along a first side of the planar electrode 4.

Method steps a) to d) may be repeated on opposite sides of the functional element 100. In this case, the second carrier film 5 is cut with a perpendicular laser beam 7 at a distance from the edge of the second carrier film 5 as far as the surface of the second planar electrode 4, so that the second carrier film 5 is divided into segments 8 to be separated and a remaining main part 9. The method steps of the method according to the invention are repeated analogously.

The

bus conductors

6a and 6b are electrically conductively connected to the planar electrodes 2, 4, respectively. The

bus conductors

6a, 6b can be connected to a voltage source via flat conductors 12, the flat conductors 12 extending from the

bus conductors

6a or 6b over the side edges of the functional element 100.

Fig. 4 shows a functional element 100' divided into a plurality of segments 11. The functional element 100' is divided into segments 11 by insulated wires 13. The insulating wire 13 is introduced in particular into the planar electrodes 2 and 4, so that the segments 11 of the planar electrodes 2 and 4 are electrically insulated from one another. The individual segments 11 can be connected independently of one another via the connecting region via the bus conductors 6a, the lines and/or the flat conductors 12 to an external voltage source, so that they can be individually actuated in the operating state. The segment 11 of the functional element 100' has two connection regions, each of which is produced according to the method of fig. 3. Thus, for example, different regions of the functional element can be switched independently, for example as a sun visor.

List of reference numerals:

1 first carrier film

2 first plane electrode

3 active layer

4 second plane electrode

5 second carrier film

6a, 6b bus conductors

7 laser beam

8 segmentation

9 major part

10 multilayer film

11 fragment

12 Flat conductor

13 insulated wire

100. 100' functional elements.

Claims

1. A method for electrically contacting planar electrodes (2, 4) of a functional element (100, 100') having electrically controllable optical properties, the functional element comprising, arranged one above the other in a plane:

-a first carrier film (1),

-a first planar electrode (2)

-an active layer (3),

-a second planar electrode (4) and

-a second carrier film (5),

wherein

a) Cutting into the first carrier film (1) by means of a perpendicular laser beam (7) such that the first carrier film (1) is divided into sections (8) to be separated and a remaining main part (9),

b) removing a segment (8) of the carrier film (1) together with a first planar electrode (2) arranged in the region of the segment (8) and at least partially together with an active layer (3) arranged in the region of the segment (8) such that the first carrier film (1) and the first planar electrode (2) form a common edge,

c) cleaning the second planar electrode (4) in such a way that the active layer (3) is completely removed in the region of the removed segments (8) in such a way that the exposed horizontal surfaces of the planar electrode (4) are exposed, and

d) electrically contacting the second planar electrode (4) at the exposed surface.

2. Method according to claim 1, characterized in that the section (8) is removed from the main part (9) of the first carrier film by means of a suction device, in particular a suction cup.

3. The method according to any of the preceding claims, wherein the bare surface of the second planar electrode (4) is cleaned by means of the laser beam (7) and/or a cleaning agent, in particular acetone.

4. The method according to any of the preceding claims, wherein the laser beam (7) has a wavelength of 5 μ ι η to 15 μ ι η, preferably 10.6 μ ι η.

5. The method according to any of the preceding claims, wherein the laser beam (7) is made of CO₂Laser generation.

6. Method according to one of the preceding claims, wherein the second planar electrode (4) is electrically contacted by means of an electrically conductive material, in particular a paste or a soldered contact.

7. Method according to any one of the preceding claims, wherein the second planar electrode (4) is electrically contacted by means of a paste with silver or a silver-containing alloy.

8. Method according to one of the preceding claims, wherein the segments (8) are configured angular, elliptical or circular, in particular quadrangular.

9. The method according to any one of the preceding claims, wherein in step a) the main portion (9) completely surrounds the segment (8) in the level of the first carrier film (1).

10. The method according to any of the preceding claims 1 to 8, wherein the segments (8) extend in step a) along the side edges of the functional element (100, 100').

11. The method according to any of the preceding claims, wherein the functional element (100') is divided into segments (11).

12. The method according to any one of the preceding claims, wherein a steering unit is provided for steering the laser beam (7) over the first carrier film (1) with respect to the surface of the first carrier film (1).

13. The method according to any of the preceding claims, wherein the functional element (100, 100') is a PDLC functional element which causes the glazing unit to appear transparent at least region by region in the case of an on-voltage supply and opaque in the case of an off-voltage supply.

14. A functional element having electrically controllable optical properties, comprising, in a face-on-face arrangement:

-a first carrier film (1),

-a first planar electrode (2)

-an active layer (3),

-a second planar electrode (4) and

-a second carrier film (5),

characterized by an electrical contact established according to any of the preceding claims.

15. A glazing unit comprising a first sheet, a second sheet and at least two interlayers between the first sheet and the second sheet, wherein a functional element (100, 100') according to claim 14 is arranged in a layer between two interlayers.