The antenna due to high inductance
The invention relates to systems for contactless transmission and reception of signals, namely contactless cards with an electronic microchip. The technical result is to create an antenna with a high inductance to improve the performance of the card, increase its reliability and reduce costs. The essence of the invention consists in the following. The antenna connection is formed by a multitude connected in series with each other coils, located on a flat substrate, made on the basis of an insulating dielectric material. The antenna includes one or more nodes having at least one coil located on a flat substrate, and mounted in series. At least one of the nodes is formed by at least two series-connected coils, stacked on one another along an axis perpendicular to the substrate plane, and separated from each other by an insulating dielectric strip paint, which allows to obtain a sufficiently large value of inductance. A method of manufacturing the antenna and this antenna in a contactless card with an electronic microchip. 12 C. and 33 C.p. f-crystals, 4 Il.
Wher is nny due to the high inductance, used, in particular, contactless cards with electronic chip.
Contactless transmission system and reception of signals currently widely used in various fields of technology. One such area is the contactless card with an electronic chip, which is a system widely used in various fields.
For example, these maps were developed road transport companies to provide our customers with tickets, and to facilitate travel on the toll road at the points of collection of toll.
Similar maps were also developed for use as a means of payment, such as e-wallet or credit card.
In addition, many firms have developed a means of identification of its employees using contactless cards with electronic chip.
The exchange of information between a contactless card with an electronic chip and a corresponding reading device information is performed using the remote electromagnetic coupling between the antenna placed in the contactless card, and another antenna located in the reader.
To ensure formim zone memory or storage device, and a microprocessor, which is connected with said antenna.
This electronic microchip has a certain input electrical capacitance provided by capacitors embedded in a microchip. Antenna and electronic microchip are usually flat and neutral substrate.
The optimal conditions of the connection between the antenna and an electronic chip, which should not be resistive, provided in the case, when we observe the law of resonance subsequent circuit, expressed by the relation
where L is the inductance of the antenna, With the value of the input capacitance,angular frequency, equal to 2f, f be a normalized frequency, for example 13.56 MHz.
Compliance with this law forces manufacturers of electronic microchips, also called the “foundry”, to place in these electronic chip capacitors to provide a sufficiently large value of electric capacitance. Thus, the manufacturing cost of electronic microchips significantly increased by the presence of these capacitors.
The expansion of areas of practical the traditional microchips, used in these maps. To reduce the cost of electronic microchip manufacturers have increasingly come to the necessity of reducing the number of capacitors that are integrated in these microchips, and, consequently, to reduce the electrical capacitance of the circuit. This provides the possibility of making electronic microchips smaller.
In order to ensure compliance with the law of resonance LC2=1 and get the best connection, it is necessary to increase the inductance L of the antenna to compensate for the reduction in the value of the input capacitance of the electronic microchip.
For antennas, fabricated by chemical etching of the layer of copper or aluminum in the formation of coils located on the dielectric plastic substrate, with the aim of increasing the inductance usually increase the number of coils. However, this solution raises a number of disadvantages.
Indeed, since any electrical circuit has electrical resistance, increasing the number of turns, which essentially corresponds to the increase in the length of this path entails a significant increase in electric fight. the consequence of this fact, the distance in which you can read such a card, is significantly reduced.
To limit the size of the electronic microchip and keep a useful section for the flow of electromagnetic waves through the map, the width of the copper paths must be less possible.
This leads to an increase in the electrical resistance of the antenna and reduce the reliability of these cards, because it increases the risk of rupture of turns of the antenna during hot lamination under pressure hulls cards.
Unit costs are fabricated by etching the antenna significantly increases. Thus, the decrease in the value received by manufacturers of electronic microchips by reducing the input capacitance, is almost completely absorbed by the excessive cost of manufacture of such antennas. As a consequence, the production and use of these cards becomes more profitable.
A brief statement of the substance of the invention
The present invention is to eliminate the above-noted disadvantages and create antennas with high inductance, allowing you to make a map that has improved characteristics in the relevant market at the present time.
Antenna connection according to the invention is formed by a set of series-connected coils arranged on a flat substrate made of a dielectric insulating material.
This antenna includes one or more nodes comprising at least one coil located on a flat substrate, and is fixed with one another, and at least one of the nodes is formed of at least two serially connected coils, stacked on top of each other along an axis perpendicular to the substrate plane, and separated from each other by an insulating dielectric strip paint, which allows to obtain a sufficiently large value of inductance.
In a preferred implementation, the antenna connection contains one or more fixed consistently nodes of the at least one loop formed by the ink deposited by screen printing on a flat substrate, and at least one of the nodes is formed by at least two series-connected coils of applied via screen-printing paint, stacked on top of each other along an axis perpendicular to the substrate plane, and hotelfree printing on a substrate.
In another aspect the invention relates to a method of manufacturing the antenna connection, which
formed by screen printing a single round of one or multiple nodes by applying a conductive paint to the surface of a flat substrate of an insulating dielectric material,
formed by screen printing an insulating strip, imposed on made by screen printing round at least one node, by applying a dielectric ink, which closes the round and leaves a visible connecting pins and zone joining the overlying turns of,
formed by screen printing one turn of the at least one node, superimposed over the insulating strip by applying a layer of conductive paint,
moreover, the second and third stages of the method is repeated one or more times when forming the antenna includes one or more nodes containing more than two stacked on top of each loop.
The proposed antenna and method of its manufacture have numerous advantages.
To offset the higher the electrical resistance inherent in the conductive polymer inks used in screen PE Idov and/or applying a thicker layer of conductive paint. When using these design solutions instant characteristics obtained by the screen printing method of the antenna containing less than three turns, comparable with the characteristics of the antenna manufactured by the method of etching a metal layer, and even exceed these specifications after conducting various mechanical tests and tests on aging under conditions of high temperature and high humidity. When it is necessary to increase the inductance of the antenna for matching with an electronic microchip, with a small internal electric capacity, increasing the number of turns for the antenna, made by screen printing, is disadvantageous, because the electrical properties rapidly deteriorate when the number of turns of more than three, i.e. there is a loss of electrical conductivity and the achievement of the limit values of inductance. The method according to the invention eliminates this disadvantage. The antenna is obtained by screen printing and is compatible with electronic microchips, has a low electric capacity.
Changing accordingly geometrical parameters of the antenna in accordance with the invention, such as raspolagaushim one on top of the other coils, you can adjust the value of inductance obtained by screen printing of the antenna to ensure proper alignment. Thus it is possible to realize the configuration of the antenna, which allows to significantly reduce the input electric capacity used in this case, the electronic microchip. This “externalization” or “removing the brackets” own electric capacitance opens very attractive prospects for reducing costs for manufacturers of electronic microchips.
The cost of the antenna, manufactured by screen printing, almost ten times lower than the cost of the antenna, is made by way of etching. Screen printing for manufacturing the antenna is a standard way to stencil in the plane (three films, three screens, the same paint).
Thus, the total cost of the card is reduced, since the internal electric capacity electronic microchip can be significantly reduced.
Brief description of drawings
The invention is further explained in the description of the preferred implementation options with reference to the accompanying drawings, in which:
Fig.1 depicts an electric circuit of bescenta step of the manufacturing method according to the invention; and
Fig.3 - antenna communication after the second step of the manufacturing method according to the invention; and
Fig.4 - antenna communication after completing step of the manufacturing method according to the invention.
A detailed description of the preferred variants of the invention
The electrical circuit card (Fig.1) contains two main components of the antenna and an electronic chip 2.
The electronic chip 2 has an internal electrical capacity 4 (Cs) provided by capacitors placed in the microchip. Electronic microchip 2 also contains the electronic part 6, which corresponds to the area of the storage device and the microprocessor.
The electronic chip 2 is connected with the antenna 8 via the path 1. The antenna 8 has an electric resistance of 10 (Rs), which causes the loss of electrical power in this circuit. This antenna also has a self-inductance 12 (Ls).
In Fig.2, 3 and 4 schematically shows an antenna as it appears after each of the three main stages of the method of manufacture. The described embodiment of the antenna containing the node of the two stacked on top of each of the coils.
This method can also be used for manufacturing the antenna with n at least two stacked on top of each other turns.
In the process of implementing the first stage of the method of manufacturing the antenna coil 16 of electrically conductive paint is applied by screen printing on a flat substrate 14 made of an insulating dielectric material (Fig.2).
The dielectric material may be a plastic material, paper or glass cloth impregnated with synthetic resin, which may be thermosetting or which is amenable to structuring under the action of ultraviolet radiation.
Used in this case, the plastic material may constitute, for example, PVC skin (PVC), a complex polyester (PET, PETG), polycarbonate (PC) or Acrylonitrile-butadiene-styrene (ABS).
Used conductive paint contains polymers and fillers in the form of conductive elements, which can be used metals. In the preferred embodiment, used paint can contain as filler silver. However, as fillers can also be used with copper or carbon. Conductive paint contains from 50 to 70% silver in the form of balls or plates. Used in the paint polymers may constitute polyesters or acrylic centuiy with the specified method of implementation used solvent is an ether glycol.
Round 16 of this antenna to the contours of the substrate. One of its ends in contact with one of the contact pins 18 to attach the antenna to an electrical or electronic element of the electronic microchip. The other end of this coil is free, so it can be attached to the second round.
In Fig.3 schematically shows an antenna after the implementation of the second phase of the method of manufacturing performed the second step of screen printing.
The second stage screen printing corresponds to the application of at least two layers of dielectric ink, forming an insulating strip 20 between the two coils. In accordance with the preferred method of implementation of each layer of paint has a thickness of 25 μm.
Dielectric paint contains polymers and amenable to structuring in the case when it is exposed to ultraviolet radiation. In accordance with the preferred method of implementing the polymer can be a synthetic resin acrylates or unsaturated polyesters.
In contrast to the above-mentioned conductive paint, which formed coils of the antenna, this dielectric paint does not contain solvent. Structures subjected to irradiation with ultraviolet rays. Structuring leads to the curing of the dielectric ink.
So, get a stable geometrical parameters of the antenna and is particularly stable thickness of the insulating strip, i.e. the distance between the two coils is not subject to change, which allows the antenna to maintain optimal performance.
In order to acquire sufficient insulating properties, the paint should have the highest possible dielectric constant. Thus the value of the dielectric constant in this case is greater than 3.
In a preferred embodiment, the implementation of the communication antenna dielectric ink used in screen printing an insulating strip has a value of 3.9.
To give the band a good insulating properties, it is necessary to apply at least two coats of paint. After structuring the layer of paint has considerable porosity, which prevents the implementation of a high insulating ability.
In order to solve the problem by screen printing to form two consecutive and stacked one on top of another layer, forming an insulating strip with high insulating ability.
And who is in contact with one of the connecting contact pins 18 of the antenna. The second end 17 stays free in order to enable the connection of the two coils together.
In Fig.4 shows the antenna after the third and final phase of the way. Made the third operation screen printing, corresponding to the formation of the coil 22. Coil 22 is placed over the coil 16 of the first node and over the insulating strip 20, which is located between the two coils in the direction of the axis, which is perpendicular to the plane of the substrate 14.
One end of coil 22 is attached to the free end 17 of the first round of 16. The second end of the coil body 22 is attached to the second connecting contact 24 of the antenna.
Thus, the antenna is formed by two series-connected coils, which are located in two different and parallel to each other planes, and each of these surfaces parallel to the plane of the substrate 14. The antenna is of a similar construction can be called antenna Z-shaped type.
Two coils forming the antenna are connected to each other by means of electric tanks, distributed along the antenna. This structure is equivalent to two coils, each of which corresponds to one of the coils of the antenna, the United pollogen between the two coils.
If L represents the inductance of each of the coils of the antenna and represents the amount of electrical capacitance, electrical resistance of the system can be expressed by the relation
From this relation it follows that the more increases the capacitance value, the more increases the total electric impedance Z of this system.
These electric capacity between the two stacked one upon the other coils varies as a function of thickness of the insulating strip. Thus, it is possible to change the actual inductance, i.e. essentially complete electrical impedance Z of the given antenna to the value of the input capacitance of the electronic microchip to provide a resonance condition.
Indeed, if the electronic microchip has a very low input electric capacity, increase the electrical capacity between two turns of the antenna, reducing the thickness of the insulating strip, resulting in increased actual inductance of the antenna.
If, on the contrary, the input electric capacity of the microchip is higher, which is I the thickness of the insulation strip.
Thus, it is possible to obtain the actual value of inductance, adjustable depending on the thickness of the insulating strip separating located one above the other coils of the antenna.
The values of electrical capacitance between the two coils of the antenna were measured, and the maximum value of electric capacity was 2,000 picofarads (pF). The electrical capacity is possible to provide the value of inductance at about 1900 nanohenry (nH).
In accordance with the invention the antenna of this type may contain one or more nodes in a single turn, and one or more nodes, consisting of several series connected coils. With each node consisting of a few turns, formed connected in series and stacked on top of each other coils, and the number and diameter of these stacked on top of each of the coils may be different from one node to another.
Antenna connection in accordance with the proposed invention can be used, in particular, contactless cards with an electronic microchip. These cards contain a flat substrate, which includes at least one antenna due to the increased inductance, which represents a relatively small internal electric capacity.
In accordance with the specific type of such contactless cards with electronic chip, the flat substrate is inserted between the two housings, the housing of the card is fixed on each side of the flat substrate, to give it the necessary rigidity.
Enclosure cards can be made from a plastic material. Used plastic material may be a PVC skin (PVC), a complex polyester (PET, PETG), polycarbonate (PC) or Acrylonitrile-butadiene-styrene (ABS).
In the case when the card case is made of plastic material, their fastening on each side of a flat substrate, which includes one or more antennas made in accordance with the invention, is carried out by hot or cold pressing of the three elements forming a map, also known as hot or cold lamination.
After phase laminating card electronic microchip is fixed and connected to one or more antennas of this map.
1. Antenna connection formed by several interconnected sequentially coils placed on a flat, is it one or more nodes, educated at least one coil (16) located on a flat substrate, and connected in series with each other, and at least one of the nodes is formed by at least two coils connected in series (16, 22), laid one on another in the direction of the axis perpendicular to the substrate plane, and separated from one another by an insulating strip (20) dielectric paint to ensure significant inductance value.
2. Antenna connection on p. 1, characterized in that the coils are made of electrically conductive ink and is formed by screen printing on a flat substrate, and the sealing strip is formed of a dielectric ink by screen printing on a flat substrate.
3. Antenna connection on p. 2, characterized in that it contains the site of two coils connected in series and stacked one upon the other in the direction of the axis perpendicular to the plane of the substrate, formed of conductive ink by screen printing and separated from each other by insulating strips.
4. Antenna connection according to any one of paragraphs.1-3, characterized in that the dielectric material from which is made a flat substrate, predstali or synthetic resin, amenable to structuring a result of exposure to ultraviolet radiation.
5. Antenna connection on p. 4, characterized in that the plastic material used as a dielectric to form the core of the flat substrate is a PVC skin (PVC), a complex polyester (PET, PETG), polycarbonate (PC) or acrylonitrilebutadienestyrene (ABS).
6. Antenna connection according to any one of paragraphs.2-5, characterized in that paint, from which by means of screen printing coils formed is a conductive polymer paint with a filler of electrically conductive elements.
7. Antenna connection on p. 6, characterized in that the electrically conductive polymer ink contains a filler, representing silver, copper or carbon.
8. Antenna connection according to any one of paragraphs.1-7, characterized in that the sealing strip is formed of at least two dielectric layers of paint.
9. Antenna connection on p. 8, characterized in that the dielectric paint, forming two layers of the insulating strip, is a polymer paint amenable to structuring under the action of ultraviolet radiation.
10. A method of manufacturing a communication antenna, characterized in that the form via screen Podlaski, made of an insulating dielectric material, is formed by screen printing an insulating strip is laid on top formed by screen printing of a coil of at least one node, by applying a dielectric paint covering the mentioned coil and leaving open contacts connect the antenna and the connection zone stacked on top of each of the coils, is formed by screen printing one turn of the at least one node formed over the insulating strip by applying a layer of conductive paint, and the second and third stages of the method is repeated at least once in the case, when the antenna contains one or many nodes, containing more than two stacked on top of each of the coils.
11. Contactless card with an electronic chip containing a flat substrate, which includes at least one antenna due to the increased inductance in accordance with any of paragraphs.1-9, associated with at least one of the electronic microchip.
12. Contactless card on p. 11, wherein the at least one electronic microchip is a small internal electric capacity.
13. Contactless card according to p. 11 helpline on each side of the flat substrate to ensure the rigidity of the card.
14. Contactless card on p. 13, characterized in that the housing of the card is made of plastic material such as PVC skin (PVC), a complex of the polyester (PET, PETG), polycarbonate (PC) or acrylonitrilebutadienestyrene (ABS).
15. Contactless card under item 13 or 14, characterized in that the housing of the card mounted on a flat substrate of the antenna by hot or cold lamination.
FIELD: access tickets and cards.
SUBSTANCE: paper body of ticket has through socket, wherein electronic module is placed, containing integral chip and antenna. Antenna is formed by at least one coil, made by printing by paint with silver dust, polymerized to hardening by thermal processing.
EFFECT: lower costs.
3 cl, 6 dwg