DE19731969A1 - Manufacturing method e.g. for electrical component having conductive structure on thermoplastic carrier substrate, such as chipcard-transponder - Google Patents

Abstract

The method manufactures an electric component through providing an electrically insulating carrier substrate, providing at least one aluminium layer (2) on at least one part of one surface of the carrier substrate, and dividing the aluminium layer into electrically mutually separated zones (3,5) by means of laser cutting. An electrical component has at least one electrically insulating carrier substrate and at least one aluminum layer (2), on which are specifically provided conductor paths (3) in the form of a planar coil. The conductor paths have connection zones or lands (6) which have a greater width than the conductor paths (3). More specifically, the thickness of the aluminium layer (2) is 20 mu m up to 50 mu m. The carrier layer used is specifically a thermoplastic plastics material.

Description

The invention relates to a method for producing a electrical component, in particular a conductive structure on a primarily thermoplastic carrier substrate preferably for use with contactless chip card Transponders.

In the case of contactless chip card transponders, there is an integrated one Circuit electrically conductive with a coil-shaped to tenne connected. There are several ways to do this Coils for the application of contactless chip cards put. Additive processes are known in which iso on a conductive substrate pastes via screen printing technology nik or deposited using the MID process. Screen printing ver Driving is costly for large-scale mass production inexpensive, but do not meet that in most applications Requirements for adequate conductivity at corre spond appropriate pressure cross-section. MID processes are plant and procedurally very complex and therefore for a mass production too expensive.

Furthermore, wire winding techniques are currently known, according to de a wound coil is placed on a carrier and there is fixed. This procedure is very inexpensive, however is later the electrical connection of the coil ends with egg integrated circuit very complex. The one at the Winding the coil used enamelled wire is before the actual stripping and contacting if necessary contact or using special contacting methods ren, such as by thermocompression, in which a Insulating varnish of the enamelled wire is softened, after which Silver and tin is melted. This procedure is ge is characterized by high wear of the electrics used for soldering  troden and poor process stability due to the in the Thick, fluctuating varnish coatings on the varnish used wire.

Subtraction methods are also used, as with for example the wet chemical, etching production of Conductor structures on a substrate carrier using mask technology cal or photolithographic process. These procedures are very complex, so that an inexpensive production of Winding is not possible. The still known methods such as punching or embossing of laminated carrier substrates meet the requirements for the required fine structure training with regard to the respective winding width and their distances with the corresponding tolerances are not.

It is therefore an object of the invention to provide a method for manufacturing provide an electrical component with which itself inexpensively and with high accuracy in particular Provide a coil antenna for contactless chip cards leaves.

To this end, the method according to the invention has the following steps:

• - Providing an electrically insulating carrier substrate
• - Provide at least one aluminum layer on at least part of a surface of the carrier substrate,
• - Splitting the aluminum layer into each other electrically separate areas using laser cutting.

The method according to the invention can be used in particular Produce fine printed circuit board structures, showing up has just made the use of aluminum laminated circuit board material in connection with the subsequent processing by a laser is partially usable. For example, a Be layering of the conductor material before laser cutting be waived without disadvantages in the formation of  Result in conductor tracks. Furthermore, a component with a Aluminum conductor track simply connected by soldering the, because aluminum compared to the known conductor materials Copper, silver, nickel, platinum and tin have a small volume related heat of fusion. Conductive adhesives can also be used bindings are used.

In addition, aluminum offers compared to the previous trace materials used also have advantages with eutectic connections or fusible links such as se in welding processes, since its melting temperature is increased by Grö orders of magnitude lower. Especially with partial thermi Aluminum offers advantages over connection technologies over other interconnect materials because it has a lower heat has conductivity. This will prevent heat from building up so quickly possibly temperature-sensitive neighboring areas directs.

It has also been found to be a particular advantage that with certain substrates such as PVC a lower map curvature results because aluminum has a heat expansion coefficient that is closer to the ent speaking value of the carrier material than that of known conductor track materials.

The above advantages were not to be expected since the invention had to enforce numerous prejudices. The expert was able to because of the numerous known After parts of aluminum as conductor material do not assume that conductor structures and especially coils for contactless chip cards with the inventive method successfully manufactured. The biggest disadvantage of Alumi nium is namely that its larger electrical Resistance requires a larger track width, to provide the necessary structures. The subject one could therefore assume that the inventor inventive method only contactless chip card coils  can be made of poor quality. Farther aluminum always has an oxide layer, which has disadvantages with regard to the processing of the circuit board material in the manufacture of the coil and in the installation and connection in a chip card could be expected. After all, aluminum has a much lower modulus of elasticity than the known conductors materials, so that just when building a chip card with an antenna coil outside the neutral zone the Ge driving the map curvature was expected.

Surprisingly, the above outlines predominate share the above disadvantages. The with the invention Process manufactured coil for a contactless chip map can be easily and particularly precisely put.

Here, by means of appropriate deflection units single laser unit multiple structures are generated, so that several electrical inventions are made with a single laser have the components in accordance with the invention manufactured "in parallel" at once. This increases throughput in production.

For areas with finer structures, the intensity of the Laser, its focus and / or the speed of movement of the Lasers are modified.

A partial application of the Conductor structure in those areas in which conductor tracks must be trained. After laser cutting arise de, unnecessary structural areas such as the Coil centers need of the electrically active structures only be isolated accordingly without completely removing them distant. Such insulation can be done with laser cutting easily achieved by the unneeded loading rich to be separated from the required areas.  

Aluminum has favorable properties, such as ductility, conductivity, for the chip card manufacturer important factors of the surface etc. and also has the main advantage over copper or silver that the surface absorption behavior also over a certain one Corrosion behavior is very stable and homogeneous. A laser cutting works with copper or silver without one additional homogeneous coating with a dark varnish is not sufficiently good.

The electrical component according to the invention has an electrical insulating carrier substrate as well as at least one aluminum nium layer on at least part of a surface of the Carrier substrate, the electrical component with the inventions process according to the invention is produced.

The aluminum layer advantageously has conductor tracks on, which have in particular the shape of a planar coil. For a later connection of the coil to other components it is advantageous if the conductor tracks in particular in ih Ren end areas have connection areas that are larger Are wider than the conductor tracks themselves.

The thickness of the aluminum layer is typically 20 microns to 50 microns, including thinner and ins special thicker aluminum layers are conceivable.

The carrier substrate and in particular a base substrate can one with an aluminum foil over the whole or part laminated carrier film made of PVC, PC, ABS, PET, PEN, polyimide or be FR4.

The invention is in the drawing based on an embodiment shown in more detail, for example.

Fig. 1 shows a chip card coil according to the invention in plan view,

FIG. 2 shows a detail of the chip card coil from FIG. 1 in an enlarged view.

Fig. 1 shows a chip card coil 1 in plan view. As can be seen particularly well in this view, the chip card tens coil 1 has a substantially rectangular outer shape. The chip card coil 1 has a not visible in this view carrier layer made of PVC, on which a thin aluminum layer 2 is brought up in the thickness of 20 microns to 50 microns.

The aluminum layer 2 is divided into two electrically separated areas by means of laser cutting. Here, an area is formed by a spiral-shaped conductor track 3 on the edge of the chip card coil 1 , which is best seen in FIG. 2. The conductor track 3 is electrically separated from a remaining area 5 by the cuts 4 which are produced in the course of the laser cutting. As can be seen most in FIG. 2, the conductor track 3 has two conductor track ends 6 , which are so enlarged that their width is larger in plan view than that of the conductor tracks 3 .

Claims (7)

1. A method for producing an electrical component, comprising the following steps:

• Provision of an electrically insulating carrier substrate,
• - Providing at least one aluminum layer ( 2 ) on at least part of a surface of the carrier substrate,
• - Divide the aluminum layer into electrically separate areas ( 3 , 5 ) by means of laser cutting.

2. Electrical component with an electrically insulating carrier substrate, with at least one aluminum layer ( 2 ) on at least part of a surface of the carrier substrate, wherein the electrical component is produced with the method according to claim 1. 3. Electrical component according to claim 2, characterized in that the aluminum layer ( 2 ) has conductor tracks ( 3 ). 4. Electrical component according to claim 3, characterized in that the conductor tracks ( 3 ) have the shape of a planar coil. 5. Electrical component according to claim 3 or claim 4, characterized in that the conductor tracks ( 3 ) have connection areas ( 6 ) which have a greater width than the conductor tracks ( 3 ). 6. Electrical component according to one of claims 2 to 5, characterized in that the thickness of the aluminum layer ( 2 ) bears 20 µm to 50 µm. 7. Electrical component according to one of claims 2 to 6, characterized in that the carrier layer has thermoplastic material.