KR101197684B1 - Magnetic Sheet, RF Identification Antenna Having Radiation Pattern Incorporated into Magnetic Sheet, and Method for Producing the Same - Google Patents

Abstract

The present invention relates to a radio frequency identification (RFID) antenna having a thin film and improved recognition distance by forming a radiator pattern directly on a magnetic sheet used for improving inductance and signal stability, and a method of manufacturing the same.

The RFID antenna of the present invention directly forms a radiator pattern on a magnetic sheet obtained by sintering ferrite or a magnetic sheet mixed with a soft magnetic powder and a binder, thereby integrating the magnetic sheet and the radiator pattern to reduce the thickness and at the same time recognize the RF signal. As a result, it is possible to improve the signal stability, and to manufacture the antenna and the magnetic sheet, and to fabricate a simpler manufacturing process and reduce the overall thickness of the antenna than the bonding structure using an adhesive layer.

RF antenna, magnetic sheet, sheet thickness, manufacturing process, recognition distance

Description

Magnetic Sheet, RF Identification Antenna Having Radiation Pattern Incorporated into Magnetic Sheet, and Method for Producing the Same}

The present invention relates to a magnetic sheet, a wireless identification antenna having a radiator pattern integrated with the magnetic sheet, and a method of manufacturing the same. In particular, the manufacturing process is simplified by forming a radiator pattern directly on a magnetic sheet used for improving inductance and signal stability. The present invention relates to a thin-film wireless identification antenna and a method of manufacturing the same, which can reduce the thickness and improve the recognition distance.

Recently, a radio frequency identification system (hereinafter referred to as "RFID system") for communicating data between a transponder equipped with an IC chip and a reader / writer or between a transponder and a reader has become widespread. The RFID system communicates data wirelessly using the antennas provided in each of the transponders and readers / writers, so communication is possible even if the transponders are moved from a few mm to several cm away from the readers / writers without contacting them. In addition, it is used in many fields such as factory management, logistics distribution and inventory management, and entrance / exit room management.

For example, recently, a mobile phone is a device using an RFID system. The RFID system of a mobile phone is a new function of a mobile phone, which enables payment and credit payment.

The RFID system of the mobile phone may be configured in a form in which an antenna for transmitting and receiving data and a magnetic sheet are attached to compensate for the attenuation of the signal due to the stability of the antenna signal and the surrounding metal material. Here, the antenna is made of FPCB (Flexible Printed Circuit Board), and is generally composed of 0.3 ~ 0.8mm thickness. Specifically, the reader antenna uses a frequency of 135 kHz or less or 13.56 MHz, and especially an RFID mobile phone using an inductive method uses a 13.56 MHz frequency to generate a sine wave, which is a wireless electromagnetic wave. The energy is transmitted to the tag, the transponder antenna, and data is received from the tag side.

Magnetic sheets are manufactured in the form of spherical or flakes of ferrite and soft magnetic metal powder having high permeability and mixed with high ductility plastic or rubber.

Since the voltage induced at the antenna is determined by Faraday's law and Lenz's law, the higher the amount of magnetic flux that interlinks the transponder antenna pattern is advantageous to obtain a high voltage signal. The amount of magnetic flux increases as the amount of soft magnetic material included in the transponder antenna coil increases, and as the material permeability increases. In particular, since the RFID system is inherently non-contact data communication, a magnetic sheet made of magnetic material having a high permeability is required to focus wireless electromagnetic waves generated from the reader antenna to the tag antenna.

Magnetic sheets are generally composed of 0.1mm to 0.5mm thick. In this case, the thicker the magnetic sheet is, the higher the inductance is, which helps improve the recognition distance of the signal and the stability of the signal. However, recent thinning and miniaturization of mobile phones have limited this increase in magnetic sheet thickness.

In the prior art, when the antenna and the magnetic sheet are physically bonded using an adhesive layer (minimum 0.02 mm), the RFID system has a thickness of 0.3 to 0.8 mm. At this time, in order to reduce the thickness of the RFID system according to the decrease in the thickness of the mobile phone, the thickness of the magnetic sheet must be reduced, which is not easy to reduce the thickness because it affects the recognition distance and the stability of the signal. In addition, in order to manufacture a magnetic sheet having a thickness of 0.1 mm or less, there is a problem of undergoing a complicated process such as a flattening process of powder through fine powdering, and a problem of severe variation in inductance due to uneven thickness during manufacturing.

Existing RFID systems use magnetic sheets attached to antennas as RFID antennas to improve recognition distance and signal stability, as proposed by the applicants in 523313 and 623518. However, as the thickness and size of electronic products are reduced, the thickness of RFID systems used in mobile phones and the like also needs to be reduced.

In the above patent, the RFID system is composed of an antenna, an adhesive layer and a magnetic sheet. To reduce the thickness of the RFID system, the thickness of the antenna or magnetic sheet must be reduced. However, when the tag antenna is manufactured to a thickness of 0.2mm or less, workability is poor and manufacturing is difficult. In addition, when the magnetic sheet is manufactured to a thickness of 0.1mm or less, the recognition distance improvement characteristics are inferior and workability is poor. Therefore, the prior art has a problem that it is difficult to manufacture less than 0.3mm considering the thickness of the adhesive layer.

The present inventors have developed a process in which the magnetic sheet directly implements antenna performance by integrating an antenna coil, that is, a radiator pattern and a magnetic sheet, so that the thickness of the RFID system can be manufactured to 0.3 mm or less. By forming a direct radiator pattern on a magnetic sheet formed by mixing a ferrite sintered sheet or a soft magnetic powder by using a silk screen or printing method, the thickness increase generated by combining and manufacturing an existing magnetic sheet and an antenna coil could be reduced. .

In general, when the emitter pattern is directly formed on the sheet by using the ferrite sintered sheet, a problem occurs when the sheet is broken during the sintering of the ferrite. Ferrite sintered sheets have a higher permeability than soft magnetic sheets, but conventionally, ferrite sintered sheets could not be used as substrates for RFID antennas due to the problem of sheet breakage when manufacturing a radiator pattern using the ferrite sintered sheets as antenna substrates.

The present inventors introduced a half-cut structure and a support layer in order to solve the problem of cracking during sintering of the ferrite sintered sheet, and found that the thermal expansion coefficient of the support layer should be similar to that of the antenna pattern. In addition, since the magnetic sheet is also increased in the process of firing the antenna pattern, it was found that it is necessary to bake at the lowest possible temperature for the stability of the antenna pattern.

Accordingly, the present invention has been made in view of the problems of the prior art, and its object is to simplify the manufacturing process by directly forming a radiator pattern on a magnetic sheet obtained by sintering ferrite or a magnetic sheet mixed-molded with a soft magnetic powder and a binder. The present invention provides a wireless identification antenna having a radiator pattern integrated with a thin magnetic sheet and a method of manufacturing the same.

Another object of the present invention is to provide a thin film type wireless identification antenna and a method of manufacturing the same, which can reduce the thickness and improve the recognition distance by forming a radiator pattern directly on a magnetic sheet used for improving inductance and signal stability. .

Still another object of the present invention is to provide a magnetic sheet having a plurality of half cuts and a ferrite sintered sheet which can secure flexibility even after sintering. .

In order to achieve the above object, according to a first aspect of the present invention, the present invention is made of a ferrite sintered sheet, a magnetic sheet formed with a plurality of half-cut to ensure flexibility after sintering; A first insulating layer formed on a surface of the magnetic sheet to support a sintered sheet having a half cut and having an insulating property; A radiator pattern formed of a conductive material on a surface of the first insulating layer, the radiator pattern comprising a first pattern of a vortex pattern and a second pattern extending outward from a distal end of the first pattern; A second insulating layer disposed between the first pattern and the second pattern to separate the first pattern and the second pattern; It provides a radio frequency identification (RFID) antenna comprising a protective layer for protecting the exposed radiator pattern.

According to a second aspect of the present invention, there is provided a magnetic sheet comprising a mixture of soft magnetic powder and a binder; A first insulating layer formed on a surface of the magnetic sheet and supporting the sheet and having an insulating property; A radiator pattern formed of a conductive material on a surface of the first insulating layer, the radiator pattern comprising a first pattern of a vortex pattern and a second pattern extending outward from a distal end of the first pattern; A second insulating layer disposed between the first pattern and the second pattern to separate the first pattern and the second pattern; It provides a radio frequency identification (RFID) antenna comprising a protective layer for protecting the exposed radiator pattern.

According to a third aspect of the invention, the present invention provides a magnetic sheet; First and second insulating layers formed on upper and lower surfaces of the magnetic sheet to support the sheet and have insulating properties; A first pattern of a helical pattern formed on the surface of the first insulating layer, a conductive connection extending from the distal end of the first pattern to a lower surface through the magnetic sheet, and a surface of the second insulating layer; A radiator pattern formed of a conductive material and having a second pattern extending outward from the other end of the connection portion; It provides an RFID antenna comprising a protective layer for protecting the exposed radiator pattern.

The first insulating layer is used as a support layer capable of buffering breakage of the pattern according to a difference in thermal expansion coefficient between the conductive paste and the magnetic sheet used to form the radiator pattern.

The RFID antenna further includes first and second terminal pads connected to both terminals of a radiator pattern on one side of the magnetic sheet.

In this case, the ferrite magnetic sheet preferably includes at least one ferrite powder selected from the group consisting of Mn-Zn, Ni-Zn, Fe-Mn and Ba.

In addition, the ferrite magnetic sheet is obtained by pressing and sintering a plurality of mixed sheets in which at least one ferrite powder selected from the group consisting of Mn-Zn, Ni-Zn, Fe-Mn and Ba mixed with a binder resin is pressed and sintered. Can be used.

Further, the magnetic sheet is at least one amorphous alloy powder and binder resin selected from the group consisting of Fe-Si-B, Fe-Si-B-Cu-Nb, Fe-Zr-B and Co-Fe-Si-B. It can be used that consists of a pressing sheet mixed in a weight ratio of 5: 1 to 9: 1 range.

In addition, the magnetic sheet may be an amorphous alloy or an alloy powder containing at least two kinds of Fe, Ni, Co.

The first insulating layer is preferably made of any one of epoxy, melamine, parylene, water glass, polypropylene (PP), polyethylene (PE), and polyamide (PI).

The radiator pattern may be formed of any one of a conductive paste made of a metal powder and an organic binder, a conductive polymer, and a conductive metal thin film.

In this case, the thickness of the first insulating layer is set in the range of 1 to 50um, and the total thickness of the RFID antenna is set in the range of 0.15 to 0.3mm.

Magnetic sheet according to the first and third features of the present invention is made of a ferrite sintered sheet, a magnetic sheet formed with a plurality of half-cut magnetic sheets or a soft magnetic powder and a binder mixed molding to ensure flexibility after sintering .

According to a fourth aspect of the invention, the present invention comprises the steps of preparing a magnetic sheet consisting of a ferrite sintered sheet or a mixture of soft magnetic powder and a binder; Forming a first insulating layer on one surface of the magnetic sheet; Forming a first pattern of a spiral pattern formed of a conductive material on the first insulating layer; A second insulating layer for selectively insulating at least a portion of the first pattern; Forming a second pattern formed of a conductive material and extending outwardly from an end portion of the first pattern through an upper surface of the second insulating layer; It provides a method of manufacturing a radio frequency identification (RFID) antenna comprising the step of forming a protective layer for protecting the exposed radiator pattern.

According to a fifth aspect of the invention, the present invention comprises the steps of preparing a magnetic sheet consisting of a ferrite sintered sheet or a mixture of soft magnetic powder and a binder; Forming first and second insulating layers on both sides of the magnetic sheet, respectively; Forming a first pattern of a spiral pattern on the first insulating layer and a conductive connection portion extending from the distal end portion of the first pattern to a lower surface through the magnetic sheet; Forming a second pattern formed of a conductive material on a surface of the second insulating layer and extending outwardly from the other end of the connection portion; It provides a method of manufacturing a radio frequency identification (RFID) antenna comprising the step of forming a first and a second protective layer for protecting the exposed first and second patterns.

In this case, the preparing of the magnetic sheet made of the ferrite sintered sheet may include forming a plurality of thick film mixing sheets using a ferrite powder and a binder using a solvent; Stacking and compressing the plurality of thick film mixing sheets to prepare a green sheet; A half cut step of cutting the green sheet to a depth of 1/2 or less of the thickness of the sheet to secure flexibility of the magnetic sheet after sintering; It is preferable to include the step of sintering the green sheet is made of the half cut.

Sintering of the green sheet is half-cut is preferably heat-treated for 2 to 24 hours in the 700 ~ 1100 ℃ range.

In addition, the manufacturing method of the RFID antenna of the present invention preferably further comprises forming first and second terminal pads connected to both terminals of the first and second patterns on one side of the magnetic sheet.

The RFID antenna is preferably a tag is formed on the surface of the magnetic sheet, the tag is patterned by using a plasma process for coating a conductive material, such as silkscreen, inkjet print, or a conductive material directly, such as silver or copper It is prepared through post-firing.

In this case, to form a tag on the magnetic sheet has an insulating property and forms a support layer for matching the thermal expansion coefficient of the magnetic sheet and the tag at the time of pattern firing, the support layer is a conductive layer of the thermal expansion coefficient of the magnetic sheet used to form the tag It may not be used if the thermal expansion coefficient of the paste is similar and if the magnetic sheet has sufficient insulating properties to form the tag. That is, when forming the radiator pattern, the step of forming the insulating layer on one or both sides according to the insulating properties of the magnetic sheet can be omitted.

According to a sixth aspect of the present invention, the present invention is made of a ferrite sintered sheet, and provides a magnetic sheet characterized in that a plurality of half cuts are formed to ensure flexibility after sintering.

According to a seventh aspect of the invention, the present invention comprises the steps of molding a plurality of thick film mixed sheet using a ferrite powder and a binder solvent; Stacking and compressing the plurality of thick film mixing sheets to prepare a green sheet; A half cut step of cutting the green sheet to a depth of 1/2 or less of the sheet thickness to secure flexibility of the magnetic sheet after sintering; It provides a method for producing a magnetic sheet comprising the step of sintering the green sheet is made of the half cut.

The RFID antenna integrated with the magnetic sheet according to the present invention can be manufactured thinner than the RFID antenna used by pasting the antenna and the magnetic sheet made of conventional FPCB. The RFID antenna system integrated with the magnetic sheet forms a radiator pattern directly on the magnetic sheet, so that a conventional FPCB antenna having a thickness of at least 0.25 mm can be manufactured to a thickness of 0.07 mm or less. In addition, in the present invention, the magnetic sheet and the antenna were manually bonded to each other by the present invention, so that the productivity may be improved while being manufactured at low cost.

Furthermore, in the present invention, the antenna recognition distance is greatly improved by narrowing the distance between the radiator pattern and the magnetic sheet.

Therefore, the RFID antenna according to the present invention directly forms a radiator pattern directly on the magnetic sheet, thereby reducing the thickness of the RFID system and improving the recognition distance and reducing the manufacturing cost.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and manufacturing method of the RFID antenna according to an embodiment of the present invention.

1 to 9 are perspective views illustrating a method of manufacturing an RFID antenna having a radiator pattern integrated with a magnetic sheet according to the first embodiment of the present invention, and FIGS. 10 to 15 are views of the first embodiment. Process cross-sectional view for explaining a method of manufacturing an RFID antenna according to the present invention.

The radio frequency identification (RFID) antenna of the present invention may be manufactured using a magnetic sheet obtained by sintering ferrite or a magnetic sheet mixed-molded with a soft magnetic powder and a binder.

Hereinafter, a method of manufacturing a magnetic sheet (that is, a ferrite sintered sheet) obtained by first sintering ferrite will be described.

First, the ferrite magnetic sheet may be manufactured in the form of a sheet using a tape casting process after mixing a ferrite powder having a composition for achieving desired characteristics with a binder, a ceramic material having insulating properties, and a solvent for molding. However, the manufacturing method of the ferrite magnetic sheet is not limited thereto, and any method capable of handling to sinter the ferrite powder may be used without limitation.

In the present invention, the ferrite powder is preferably prepared in a composition such as Mn-Zn, Ni-Zn, Fe-Mn or Ba. A small amount of elements such as calcium carbonate, silicon oxide, vanadium and bismuth may be added to the ferrite powder within 0.01 to 5% to improve properties.

Ferrite magnetic sheet according to the present invention is prepared as follows. First, a powder of Mn-Zn, Ni-Zn, Fe-Mn, or Ba composition is mixed with a binder resin, where necessary to adjust the viscosity, for example, toluene, alcohol, or volatiles such as methyl ethyl ketone (MEK). A solvent can be added and mix | blended.

Examples of the binder that can be used in the present invention include, but are not limited to, water glass, polyimide, polyamide, silicone, phenol resin, acrylic, and the like. In addition, the ceramic powder to be added for the insulating properties using kaolin, talc and the like, if there is an electrical insulating properties, can be used without being limited to the above composition. The mixing ratio of ferrite powder and binder resin is preferably selected between 4: 1-9: 1 volume ratios. If the mixing ratio is less than 4: 1, it is difficult to obtain the inductance required in RFID communication, and at the mixing ratio exceeding 9: 1, it is difficult to manufacture the sheet. The blended ferrite powder and the binder resin are applied onto a thick film having a thickness of 0.5 mm or less using a solvent and dried to form a mixed sheet.

The dried ferrite mixed sheet may obtain a green sheet 10 shown in FIG. 1 through a process of stacking and compressing a plurality of mixed sheets, and manufacturing the mixed sheet by stacking and compressing the plurality of mixed sheets. The height and density of the sheet can be controlled. In this case, in order to manufacture the thickness of the magnetic sheet subjected to the final sintering process to 0.15mm, for example, 10 sheets of 20um thick mixed sheets may be laminated and compression molded.

The method of compression molding the plurality of mixed sheets can be carried out by one of warm press, warm rolling, cold hydrostatic pressure and warm hydrostatic pressure, for example. The temperature at the time of warm hydrostatic pressure can be performed at 70 degreeC, for example.

The green sheet 10, which is a compressed molded sheet manufactured as described above, is subjected to a half cut process to secure flexibility of the magnetic sheet after sintering. In the half cut process, the green sheet 10 is cut to a depth of 1/2 or less of the sheet thickness as shown in FIG. 2. The half cut 11 may be formed in a matrix pattern form, and may be modified in another pattern form.

The green sheet 10 which becomes the half cut 11 is subjected to heat treatment for 2 to 24 hours in the range of 700 to 1100 ° C. for sintering, thereby obtaining the magnetic sheet 12 shown in FIG. 3. At this time, the heat treatment atmosphere may be an atmospheric atmosphere, hydrogen, nitrogen atmosphere and the like, it may be pressure sintering for the sheet flatness.

On the other hand, in the present invention, the magnetic sheet 12 may use a composite sheet prepared by mixing a soft magnetic powder and a resin for a binder. In this case, the soft magnetic powder may use a pure metal powder and a metal alloy powder. It is preferable.

In the above conditions, the metal alloy powder is generally used by mixing a ferromagnetic Fe, Ni, Co elements in a predetermined ratio, typically Ni and Fe elements in an atomic ratio of 80:20 or 50:50, such as permalloy or Fe and Co elements can be mixed and used at 50:50.

In addition, in the present invention, the metal alloy powder may be made of amorphous or nanocrystalline, the composition is Fe-Si-B, Fe-Si-B-Cu-Nb, Fe-Zr-B, Co-Fe-Si- B etc. can be used.

Looking at the composition that can be manufactured in the amorphous structure in detail, in the case of the Fe-Si-B alloy, the higher the content of the metal, including Fe, the main element, the higher the saturation magnetic flux density, but when the content of Fe element is excessive, the amorphous is formed. Since the following is difficult, it is preferable in the present invention that the content of Fe is 70-90 atomic%. In addition, the amorphous forming ability of the alloy is the best when the sum of Si and B is in the range of 10-30 atomic%. In order to prevent corrosion in this basic composition, corrosion resistant elements such as Cr may be added within several atomic%.

In the present invention, the Fe-Si-B-Cu-Nb alloy preferably has 73-80 atomic% of Fe and 1-5 atomic% of the sum of Si and B. Such a composition range can be easily precipitated into the crystal grains of the nano phase when the heat treatment described later to the amorphous alloy produced in the form of a ribbon.

In the present invention, in the case of the Fe-Zr-B alloy, Fe is preferably 85-93 atomic%, Zr is 5-10 atomic%, and B is 2-5 atomic%. In this composition region, the alloy can be easily precipitated into grains of the nano phase by the heat treatment described later.

In the present invention, in the case of Co-Fe-Si-B alloy, it is preferable that Co is 71-85 atomic%, and the sum of Si and B is 12-21 atomic%, and if necessary, Mo, Cr, Ni, etc. It is possible to add within%. At this time, the sum of the contents of Cr and Ni is preferably within 2-7 atomic%. The lower the Co content, the lower the maximum magnetic flux density but the higher the permeability. Therefore, the lower the Co content is advantageous to obtain high inductance, but the bias characteristics caused by DC current vary greatly depending on the Co content.

In the present invention, the metal alloy powder is produced by a gas spraying or water spraying process, in the case of amorphous powder can be prepared by the above process, but can be prepared by the RSP (Rapid Solidification Process) process to uniform the particle size of the powder have. The method for preparing the amorphous powder by the RSP process is first made into a ribbon form by the RSP process, and then into a powder through a grinding process.

The magnetic sheet in which the soft magnetic powder and the resin for the binder according to the present invention are combined is manufactured as follows.

First, the soft magnetic powder has a composition selected from pure metal or metal alloy powder, the form is not limited to the form of powder, granules, needles and the like.

The powder is then processed into powder using a milling method known in the art such as a ball mill. The processed alloy powder may have a thin plate-like shape in a thin film form, and the plate-like shape may be circular, square or needle-shaped, and the present invention is not limited by the form of the alloy powder.

The powder prepared as described above may be made to be excellent in magnetic properties by removing the stress that may occur in the process by heat treatment, when manufacturing the magnetic sheet for RFID antenna of the present invention using the alloy powder prepared as described above. The high frequency characteristics of the magnetic sheet can be improved. In the present invention, the heat treatment temperature is 300 ℃ to 900 ℃, heat treatment time is preferably performed within a maximum of 10 hours.

The alloy powder prepared as described above is mixed with the binder resin, and if necessary, it may be added by mixing with other volatile solvents such as polyvinyl alcohol, alcohol or toluene to adjust the viscosity. Examples of the binder resin that can be used in the present invention include, but are not limited to, rubber, polyimide, polyamide, urethane, silicone, phenol resin, acrylic, and the like.

The mixing ratio of the alloy powder and the resin for the binder is preferably selected between 5: 1-9: 1 by weight. If the mixing ratio is less than 5: 1, it is difficult to obtain the inductance required in the RFID communication, and at the mixing ratio exceeding 9: 1, it is difficult to manufacture the sheet. The blended alloy powder and the binder resin are applied onto a thick film having a thickness of 0.5 mm or less and dried.

The thick film-formed mixed sheet manufactures the primary compacted magnetic sheet 12 in a manner of continuously passing, for example, a pressing roll composed of a pair of upper and lower rolls in order to increase the density.

The method for pressing molding the mixed sheet may be carried out by, for example, one of warm rolling, warm pressing or cold rolling, and cold pressing. The temperature at the time of warm rolling can be performed at 70 degreeC, for example.

When the soft magnetic powder 12 is manufactured by combining the soft magnetic powder and the binder resin as described above, a cracking problem does not occur, and thus a half cut process such as a ferrite magnetic sheet 12 made of ferrite is not performed.

In the following description of the first embodiment, the use of the ferrite magnetic sheet 12 is described as an example for convenience of description, and the drawing shows a manufacturing process diagram using the ferrite magnetic sheet 12.

As shown in FIGS. 9 and 15, the RFID antenna 1 according to the first embodiment of the present invention has a spiral shape with a plurality of turns on the upper surface of the magnetic sheet 12 on which the first insulating layer 13 is formed. The radiator pattern 20 which consists of a shape is arrange | positioned.

In the first embodiment, both ends of the radiator pattern 20 are connected to one side of the magnetic sheet 12 in order to connect with an internal circuit of an RFID system, that is, a transponder, on a two-dimensional plane above the first insulating layer 13. The first and second terminal pads 18a and 18b are disposed to be connected to each other.

In this case, the vortex-shaped radiator pattern 20 has a first entering the helical shape from the first terminal pad 18a so as to avoid overlapping of the pattern when it is drawn out from the vortex-shaped pattern to the outside. The structure in which the pattern 14 and the second pattern 16 having a linear shape for connection with the second terminal pad 18b from the inside of the first pattern 14 are separated by the second insulating layer 15 is described. Have.

Hereinafter, a manufacturing process of manufacturing the RFID antenna 1 according to the first embodiment of the present invention as shown in FIGS. 9 and 15 will be described with reference to FIGS. 4 to 15.

First, as shown in FIGS. 4 and 11, an insulating layer 13 is formed on one surface of the ferrite magnetic sheet or soft magnetic magnetic sheet 12 to form a radiator pattern for an RFID system.

In the above process, the first insulating layer 13 is to protect the electrical insulation characteristics and the radiator pattern formed in the subsequent process, and the pattern may be broken during expansion of the sheet and shrinkage of the radiator pattern during the annealing process for the pattern firing process. It must be able to buffer In particular, when using a ferrite sintered sheet as a magnetic sheet, the first insulating layer 13 serves as a support layer for supporting the sintered sheet made of a half cut.

The first insulating layer 13 may be formed of a composition of epoxy, melamine, parylene, water glass, polypropylene (PP), polyethylene (PE), or polyamide (PI), and may be formed of a material having electrical insulation properties. Can be used without limitation. As the method of forming the first insulating layer 13, spray coating, dip coating, spin coating, or the like, which is a general coating method, may be used. For example, a deposition method such as CVD and plasma may be applied.

The thinner the first insulating layer 13 is, the better the thickness of the first insulating layer 13 is, and the thickness of the magnetic sheet 12 to protect the subsequent antenna pattern. In general, the thickness of the first insulating layer 13 is 100 um or less, preferably in the range of 1 to 50 um, for example, 20 um.

The ferrite or soft magnetic magnetic sheet 12 on which the first insulating layer 13 is formed is washed to form a pattern, and then the radiator pattern 20 is formed by a pattern forming process using a conductive paste.

In order to form the radiator pattern 20 having the above structure, first, as shown in FIGS. 5 and 12, a pattern forming process using a conductive paste is performed on the upper surface of the first insulating layer 13 to form the first pattern 14. To form.

The conductive paste is composed of a metal powder and an organic binder, and the metal powder is a metal having high electrical conductivity such as silver (Ag) or copper (Cu). In this case, the sintering temperature of the first pattern 14 is lower the smaller the size of the metal powder. For example, when the size of the metal powder is reduced to several tens of nanometers or less, it can be sintered at 130 ° C. The soft magnetic magnetic sheet 12 is composed of a magnetic powder and a binder resin, so that the binder resin is melted or carbonized at 150 ° C. or higher, thereby making it difficult to maintain its shape. Therefore, when the soft magnetic magnetic sheet 12 is used, when the conductive first pattern 14 is formed by using a conductive paste on its cross section, a paste made of nano powder that can be sintered at low temperature should be used.

In addition, the conductive paste may be a conductive polymer in addition to the case where a common metal powder and a binder is mixed. The conductive polymer is made of a liquid phase, and can be cured at low temperatures. Generally, the conductive polymer is less conductive than a metal composition such as copper (Cu) or silver (Ag), but may serve as an antenna.

The pattern forming process may form the conductive first pattern 14 to 10 μm or more, and in the case of using a conductive thin film, for example, copper foil, the copper foil is adhered to the upper surface of the first insulating layer 13. For example, an etch process used in a semiconductor process, a silk screen process, an inkjet process, or the like when using a conductive paste, or a plasma process of directly coating a conductive material is used to form the first pattern 14 having a spiral shape. The low temperature heat treatment of the patterned conductive paste is used to convert the conductive paste into a conductive film. The pattern forming process may be used without limitation as long as it is a process capable of forming a conductive pattern.

The eddy shape of the conductive first pattern 14 may be circular or rectangular, and the shape of the radiation pattern for use as an antenna may be modified into other shapes.

Next, as shown in FIGS. 6 and 13, the first pattern 14 is insulated from the inner end of the first pattern 14 at a position where the second pattern 16 for connection with the second terminal pad 18b is to be formed. In order to form the second insulating layer 15. In this case, the second insulating layer 15 may be formed only at the position where the second pattern 16 is to be formed or may be formed entirely on the upper surface. The second insulating layer 15 is formed using the same material and method as the first insulating layer 13, and the thickness thereof may be, for example, 5 μm.

Thereafter, as shown in FIGS. 7 and 14, a second pattern for connecting the second terminal pad 18b through the upper surface of the second insulating layer 15 from the inner end of the first pattern 14 ( 16 is formed of the same material, method and thickness as the first pattern 14. The first pattern 14 and the second pattern 16 form a radiator pattern 20.

Subsequently, the exposed first and second patterns 14 and 16 may be damaged by external physical forces, so that the same materials and methods as the first and second insulating layers 13 and 15 may be used for protection. The entire upper surface is coated to form the protective layer 17 shown in FIGS. 8 and 15. Since the protective layer 17 is not used as a support layer like the first insulating layer 13, the thickness thereof may be 10 μm or less, for example, 5 μm.

Finally, as shown in FIG. 9, the first and second terminal pads 18a and 18b connected to both ends of the first pattern 14 and the second pattern 16 are spaced apart from one side of the magnetic sheet 12. To form. The first and second terminal pads 18a and 18b may be formed of the same material and method as the first pattern 14 and the second pattern 16, or may be formed using other well-known metal pattern forming methods.

As described above, when manufacturing the RFID antenna 1 in which the magnetic sheet 12 and the radiator pattern 20 are integrated according to the first embodiment of the present invention, the FPCB antenna, which was previously manufactured to a thickness of at least 0.25 mm, is 0.07 mm. Since it can manufacture with the following thickness, it is possible to manufacture the thin film to the total thickness of the RFID antenna 1 also less than 0.3 mm, Preferably it is 0.15 mm.

In this case, by integrating the magnetic sheet 12 and the radiator pattern 20, the gap between the magnetic sheet 12 and the radiator pattern 20 may be further reduced to greatly improve antenna performance, that is, recognition distance up to 55 mm. It became.

Therefore, the RFID antenna 1 according to the first embodiment of the present invention can be applied to various devices such as PDAs, notebook computers, traffic cards, credit cards, access cards, etc. in a manner similar to that applied to not only a slim mobile phone. .

In addition, the magnetic sheet 12 may be used as an EMI sheet that blocks unwanted electromagnetic waves in addition to being used as a substrate for an RFID antenna.

Hereinafter, a method of manufacturing an RFID antenna having a radiator pattern integrated with a magnetic sheet according to a second embodiment of the present invention will be described with reference to FIGS. 16 to 25.

As illustrated in FIG. 25, the RFID antenna 3 according to the second embodiment of the present invention has a spiral-shaped first pattern 14 formed on an upper surface of the magnetic sheet 12 on which the first insulating layer 13 is formed. ) And a linear second pattern 16b is formed on the lower surface of the magnetic sheet 12 on which the second insulating layer 13a is formed, and the first pattern 14 and the second pattern 16b are formed. The magnetic sheets are connected to each other by the conductive connecting portions 16a filled in the through holes 12a and formed at both ends of the first pattern 14 and the second pattern 16b in the same manner as in the first embodiment (see FIG. 9). One side of 12 is connected to the first and second terminal pads 18a and 18b connected to the RFID system, i.e., the internal circuit of the transponder.

In the description of the RFID antenna 3 according to the second embodiment of the present invention, the same components are assigned to the same components as the RFID antenna 1 of the first embodiment, and detailed description thereof will be omitted.

First, referring to FIG. 16, a green sheet 10 prepared by pressing and stacking a plurality of ferrite mixing sheets is prepared in the same manner as in the first embodiment, and then using a punch to form a pattern on both sides as shown in FIG. 17. A through hole 12a penetrating the green sheet 10 is formed.

Thereafter, a half cut process is performed to secure the flexibility of the magnetic sheet after sintering in the same manner as in the first embodiment, and then the sintering process is performed to obtain the magnetic sheet 12 shown in FIG.

The RFID antenna 3 according to the second embodiment of the present invention may use a magnetic sheet obtained by sintering ferrite as in the first embodiment, or a magnetic sheet obtained by mixing and molding a soft magnetic powder and a binder. However, for the sake of convenience of explanation, only the magnetic sheet obtained by sintering ferrite will be shown and described by way of example.

Thereafter, the sintered ferrite magnetic sheet 12 shown in FIG. 18 forms a first insulating layer 13 on the upper surface of the magnetic sheet 12, as shown in FIG. As shown in FIG. 20, the second insulating layer 13a is formed on the lower surface of the magnetic sheet 12.

The first and second insulating layers 13 and 13a are for protecting the electrical insulating properties and the radiator pattern formed in a subsequent process, and may occur during sheet expansion and shrinkage of the radiator pattern during an annealing process for the pattern firing process. The same thickness is formed by using the same method and material as those in the first embodiment so as to prevent breakage of the existing pattern.

Next, as shown in FIG. 21, the conductive first pattern 14 having a spiral shape is formed by using a conductive paste on the upper portion of the first insulating layer 13 formed on the upper surface of the magnetic sheet 12 as in the first embodiment. At the same time, the conductive hole 16a connected to the inner end 14a of the first pattern 14 is formed in the through hole 12a.

The conductive connecting portion 16a may be filled by, for example, forming a first pattern 14 by a silk screen process using a conductive paste and sintering the conductive paste in the through hole 12a. The conductive paste is melted to form a conductive connection portion 16a connected to the first pattern 14.

Thereafter, the same method and material as that of the first insulating layer 13 are used on the entire upper surface of the first pattern 14, as shown in FIG. Form layer 17.

Subsequently, as shown in FIG. 23, a conductive paste is used on the second insulating layer 13a formed on the lower surface of the magnetic sheet 12 to connect the conductive connecting portions 16a and the second terminal pads 18b to each other. The conductive second pattern 16b is formed using the same method and material as the first pattern 14.

Thereafter, as shown in FIG. 24, the second protective layer may be formed on the lower surface of the magnetic sheet 12 using the same method and material as the first protective layer 17 to protect the exposed second conductive pattern 16b. 17a).

23 and 24 show the magnetic sheet 12 inverted for clarity.

Lastly, although not shown in FIG. 25, the first and second terminal pads 18a, which are connected to both ends of the first pattern 14 and the second pattern 16b, as shown in the first embodiment shown in FIG. 9. 18b) is formed on one side of the magnetic sheet 12 at intervals. The first and second terminal pads 18a and 18b may be formed of the same material and method as the first pattern 14 and the second pattern 16, or may be formed using other well-known metal pattern forming methods.

As described above, when manufacturing the RFID antenna 3 in which the magnetic sheet 12 and the radiator pattern 20 are integrated according to the second embodiment of the present invention, it is possible to manufacture a thin film similar to the first embodiment. It is possible to further reduce the distance between the magnetic sheet 12 and the radiator pattern 20 can greatly improve the recognition distance of the antenna.

In the following, in order to find out in detail the performance of the RFID antenna of the present invention, a sample was prepared to measure the thickness and the recognition distance of the radiator pattern.

<Examples>

Example 1

In Example 1, first, a molded sheet was manufactured using Fe-Mn powder to prepare a ferrite sintered sheet. Specifically, Fe-Mn powder and water glass serving as a binder were blended to suit the composition ratio, and 0.15% kaolin was added to improve the insulation characteristics. Subsequently, in order to evenly mix the Fe-Mn powder, the binder, and the additive, MEK, which is a solvent, was mixed and mixed using a ball mill equipment. The slurry prepared by mixing Fe-Mn powder, a binder, an additive, and a solvent was molded to a thickness of 20 um using a tape casting process. In order to manufacture the final sintered sheet with a thickness of 0.15 mm, 10 sheets were laminated and compressed using a warm water press.

Ferrite molded sheet prepared as described above was prepared a magnetic sheet by the process of FIGS. That is, a half cut process was performed for flexibility of the sheet after sintering. The half cut process cuts the molded sheet to a depth of 1/2 or less of the sheet thickness. The half cut sheet was subjected to 24 hours in a 900 ℃ sintering furnace for sintering.

Using the ferrite sintered sheet obtained by the above sintering process as a magnetic sheet, the manufacturing process shown in FIGS.

That is, on one side of the ferrite magnetic sheet, a support layer was formed to a thickness of 20 μm by using a CVD process using paraline as an insulating layer.

The antenna pattern was formed to a thickness of 10um on the surface on which the support layer was formed by the silkscreen process. The antenna pattern was formed in three turns with a quadrangle, and was formed in a multi-layered structure using an insulating layer of 5um to prevent the overlap between the inner and outer conductors.

As the conductive paste for forming the antenna pattern, a nano-sized silver powder was used, and heat treatment was performed at 130 ° C. for 30 minutes after the pattern formation.

Finally, in order to protect the antenna pattern, a protective film having a thickness of 5 μm was formed by CVD using paraline.

Example 2

In Example 2, the ferrite sintered sheet and the antenna manufacturing process were manufactured in the same manner as in Example 1, but the ferrite sintered sheet had a thickness of 0.1 mm.

Example 3

Example 3 was the same as in Example 2 to prepare a ferrite sintered sheet. The sintered ferrite sintered sheet prepared in the above process used a silicon coating as a support layer to form a pattern on the cross section. At this time, the coating thickness was 50um. After the above process, the same process as in Example 1 was applied to form an antenna pattern, and only silver nano paste was used as the conductive paste.

Example 4

Example 4 the ferrite sintered sheet was prepared in the same manner as in Example 2. The ferrite sheet prepared in the above process used a polyamide film as a support layer to form a pattern in the cross section. At this time, the thickness of the polyamide film was 25 μm. After the above process, the same process as in Example 1 was applied to form an antenna pattern, and only silver nano paste was used as the conductive paste.

Example 5

In Example 5, the ferrite sintered sheet was manufactured and the support layer was formed in the same manner as in Example 4. After the above process, to form an antenna pattern, a copper foil having a thickness of 25 um was bonded to form an antenna pattern using an etching process.

Example 6

In the sixth embodiment, the processes of FIGS. 16 through 25 are performed such that the RFID antenna pattern has the structure of the second embodiment shown in FIG.

In Example 6, first, the ferrite molded sheet was manufactured in the same manner as in Example 1, and then punching holes were formed using punches to form patterns on both surfaces.

The molded sheet manufactured in the above process was subjected to the half cut process and the sintering process as in Example 1. The sintered ferrite sintered sheet had a thickness of 0.15 mm, and a paraline coating was formed to a thickness of 20 um on both sides as in Example 1 to form an antenna pattern on both sides.

The ferrite sintered sheet coated in the above process has a thickness of 10 μm on the one surface of the first pattern shown in FIG. 21 using silver nano paste, and the second pattern of FIG. Patterning was carried out under the same conditions as in Example 1. At this time, in order to connect each pattern, a silver nano paste was filled in a punching hole and fired.

Lastly, in order to protect the antenna pattern, a protective film having a thickness of 5 μm was formed by CVD using paraline on both sides.

Example 7

Example 7 prepared an amorphous alloy Fe-Si-B to prepare a raw material of the magnetic sheet. Specifically, Fe-B was used as a starting material, and electrolytic iron (Fe) and Si were mixed therein to match the composition ratio, and melted together in a melting furnace, thereby preparing an ingot having a Fe ₇₉ (Si, B) ₂₁ composition. . Subsequently, after charging the ingot into the high frequency induction furnace, power was applied to the high frequency induction furnace to add high frequency energy to the ingot to completely melt the ingot. Subsequently, a high temperature molten metal was sprayed onto a cooling roll rotating at high speed through a nozzle to produce an amorphous alloy ribbon having a thickness of 0.02 mm. The amorphous ribbon was prepared into a powder through a hammer mill. The prepared powder was heat treated at 320 ° C. for 7 hours.

The alloy powder prepared as described above was mixed with a urethane resin in a ratio of 7: 1 by volume, coated on a substrate, dried, and separated to prepare a mixed sheet. The mixed sheet was rolled warm at 70 ° C. to prepare a magnetic sheet that was 0.2 mm thick.

The soft magnetic sheet manufactured under the above conditions was subjected to the same process as in Example 1 to form the RFID antenna pattern in the same structure as in the first embodiment. At this time, since the urethane resin, which is a binder of the magnetic sheet, was melted at 120 ° C. or higher, a paste made of nano powder capable of firing the pattern at 120 ° C. or lower was used.

Comparative Example 1

In Comparative Example 1, the same ferrite sintered sheet as in Example 1 was used as the magnetic sheet, and the magnetic sheet was manufactured by the same process as in Example 3. The thickness of the magnetic sheet was prepared in the same manner as in Example 3. RFID antenna pattern was manufactured in 0.25mm thickness by FPCB process, the shape of the antenna pattern was prepared in the same manner as in Example 3. Double-sided tape (9461P, 3M, USA) was used to attach the antenna pattern and the magnetic sheet, and the thickness of the tape was 0.025 mm.

Comparative Example 2

In Comparative Example 2, an amorphous powder having a composition of Fe ₇₉ (Si, B) ₂₁ was used as a raw material of the magnetic sheet, and the same procedure as in Example 7 was performed. The magnetic sheet was prepared in thickness of 0.15 mm. The RFID antenna pattern was manufactured to a thickness of 0.25 mm by the FPCB process, the shape of the antenna pattern was prepared in the same manner as in Example 3. Double-sided tape (9461P, 3M, USA) was used to attach the antenna pattern and magnetic sheet, and the tape thickness was 0.025 mm.

[Experiment result]

Thickness and RFID recognition distance measurement

The present invention aims to reduce the thickness and improve the recognition distance of an RFID antenna by integrating a ferrite magnetic sheet or a soft magnetic magnetic sheet and a radiator pattern. Therefore, after measuring the thickness of the Examples 1 to 7 and Comparative Examples 1 to 2 and the recognition distance of the antenna are shown in Table 1 below the results.

To measure the recognition distance of the antenna, a mobile phone including an RFID chip was installed by installing a Moneta of SK TELECOM, an RFID reader, together with a reader, and installing the RFID antennas manufactured in Examples 1 to 7 and Comparative Examples 1 to 2 on a battery pack. The perceived distance was measured.

Structure features Sheet thickness Antenna thickness Total thickness Recognition distance Example 1 Ferrite Magnetic Sheet
+
Paraline support layer
+
Silver nano pattern 0.15mm 0.05mm 0.2mm 55 mm Example 2 Ferrite Magnetic Sheet
+
Paraline support layer
+
Silver nano pattern 0.1mm 0.05mm 0.15mm 47 mm Example 3 Ferrite Magnetic Sheet
+
Silicon support layer
+
Silver nano pattern 0.1mm 0.07mm 0.17mm 43 mm Example 4 Ferrite Magnetic Sheet
+
Polyamide support layer
+
Silver nano pattern 0.1mm 0.07um 0.17mm 44 mm Example 5 Ferrite Magnetic Sheet
+
Polyamide support layer
+
Copper Foil Pattern 0.1mm 0.07um 0.17mm 48 mm Example 6 Ferrite Magnetic Sheet
+
Paraline support layer
+
Silver Nano Pattern (Double Sided) 0.15mm 0.07mm 0.22mm 47 mm Example 7 Soft Magnetic Magnetic Sheet
+
Paraline support layer
+
Silver nano pattern 0.15mm 0.05mm 0.2mm 32 mm Comparative Example 1 Ferrite Magnetic Sheet
+
FPCB antenna 0.1mm 0.275 mm 0.375mm 41 mm Comparative Example 2 Soft Magnetic Magnetic Sheet
+
FPCB antenna 0.15mm 0.275 mm 0.425mm 30 mm

Referring to Table 1 above, it can be seen that the use of the ferrite sintered sheets of Examples 1 to 6 as the magnetic sheet is significantly longer than that of Example 7 using the soft magnetic magnetic sheet. In addition, it can be seen that using a paraline as a support layer shows a longer recognition distance than using other insulators.

In addition, as in Comparative Example 1, even when using a ferrite sintered sheet, when the FPCB antenna is attached using double-sided tape, a total thickness of 0.375 mm and a recognition distance of 41 mm are obtained. The recognition distance was shorter than the thickness of 0.17mm.

In the RFID antenna of the present invention, Examples 1 to 6 showed a longer recognition distance than Comparative Examples 1 and 2 even when the total thickness was thin, and Example 1 having a total thickness of 0.2 mm showed a very good recognition distance of 55 mm. In Example 2, although the recognition distance is excellent as 47mm, it can be seen that the total thickness can be realized as a thin film of 0.15mm.

In general, although the ferrite sintered sheet is superior to the soft magnetic magnetic sheet, in the past, due to a problem of breaking during ferrite sheet sintering, the radiator pattern was not directly formed on the ferrite sintered sheet. And this problem is solved by using the and support layer, and as a result, it is possible to implement an RFID antenna with a thinner antenna and a significantly improved recognition distance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein. Various changes and modifications may be made by those skilled in the art.

The present invention relates to an RFID antenna with a thinner antenna and a significantly improved recognition distance. The present invention relates to a RFID system transponder antenna, which can be used for various types of mobile phones, PDAs, notebook computers, transportation cards, credit cards, and access cards. Applicable to the device.

1 to 9 are process perspective views for explaining a method of manufacturing an RFID antenna having a radiator pattern integrated with a magnetic sheet according to the present invention;

10 to 15 are cross-sectional views illustrating a method of manufacturing the RFID antenna according to the first embodiment;

16 to 25 are cross-sectional views illustrating a method of manufacturing the RFID antenna according to the second embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: green sheet 11: half cut

12: magnetic sheet 12a: through hole

13,13a, 15: insulating layer 14: first pattern

14a: inner end 16: second pattern

16a: connection part 17, 17a: protective layer

18a, 18b: terminal pad

Claims (29)

delete A magnetic sheet formed by mixing and molding soft magnetic powder and a binder; A first insulating layer formed on a surface of the magnetic sheet and supporting the sheet and having an insulating property; A radiator pattern formed of a conductive material on a surface of the first insulating layer, the radiator pattern comprising a first pattern of a vortex pattern and a second pattern extending outward from a distal end of the first pattern; A second insulating layer disposed between the first pattern and the second pattern to separate the first pattern and the second pattern; A protective layer for protecting the radiator pattern, The first insulating layer is an RFID antenna, characterized in that used as a support layer capable of buffering the break of the pattern according to the difference in thermal expansion coefficient between the conductive paste and the magnetic sheet used to form the radiator pattern. delete The RFID antenna of claim 2, further comprising first and second terminal pads connected to both terminals of a radiator pattern on one side of the magnetic sheet. delete delete According to claim 2, wherein the magnetic sheet is at least one amorphous alloy powder selected from the group consisting of Fe-Si-B, Fe-Si-B-Cu-Nb, Fe-Zr-B and Co-Fe-Si-B And RFID resin, characterized in that the binder resin is made of a pressing sheet mixed in a weight ratio of 5: 1 to 9: 1 range. The RFID antenna of claim 2, wherein the magnetic sheet is made of an amorphous alloy or an alloy powder containing at least two of Fe, Ni, and Co. 4. The RFID antenna of claim 2, wherein the first insulating layer is formed of any one of epoxy, melamine, parylene, water glass, polypropylene (PP), polyethylene (PE), and polyamide (PI). The RFID antenna of claim 2, wherein the radiator pattern is formed of any one of a conductive paste consisting of a metal powder and an organic binder, a conductive polymer, and a conductive metal thin film. The RFID antenna of claim 2, wherein the thickness of the first insulating layer is set in a range of 1 to 50 μm. The RFID antenna of claim 2, wherein the total thickness of the RFID antenna is set in a range of 0.15 to 0.3 mm. Magnetic sheets; First and second insulating layers formed on upper and lower surfaces of the magnetic sheet to support the sheet and have insulating properties; A conductive pattern formed of a conductive material on a surface of the first insulating layer and extending from the distal end portion of the first pattern to the lower surface through a through hole 12a passing through the magnetic sheet; A radiator pattern formed of a conductive material on a surface of the second insulating layer and formed of a second pattern extending outward from the other end of the connection part; And a protective layer for protecting the exposed radiator pattern. The method of claim 13, wherein the magnetic sheet is made of a ferrite sintered sheet, a magnetic sheet formed with a plurality of half-cut magnetic sheets or soft magnetic powder and a binder mixed molding to ensure flexibility after sintering, characterized in that RFID antenna. The RFID antenna of claim 13, wherein the radiator pattern is formed of a conductive paste or a conductive polymer comprising a metal powder and an organic binder. delete Preparing a magnetic sheet made of a ferrite sintered sheet or a mixture of soft magnetic powder and a binder; Forming first and second insulating layers on both sides of the magnetic sheet, respectively; Forming a first pattern of a spiral pattern on the first insulating layer and a conductive connection portion extending from the distal end portion of the first pattern to a lower surface through the magnetic sheet; Forming a second pattern formed of a conductive material on a surface of the second insulating layer and extending outwardly from the other end of the connection portion; And forming first and second protective layers for protecting the exposed first and second patterns. 18. The method of claim 17, wherein preparing a magnetic sheet made of the ferrite sintered sheet Molding a plurality of thick film mixing sheets using a ferrite powder and a binder; Stacking and compressing the plurality of thick film mixing sheets to prepare a green sheet; A half cut step of cutting the green sheet to a depth of 1/2 or less of the thickness of the sheet to secure flexibility of the magnetic sheet after sintering; And sintering the green sheet made of the half cuts. 19. The method of claim 18, wherein the half cut green sheet is sintered at 700 to 1100 ° C for 2 to 24 hours. 18. The method of claim 17, wherein the first and second insulating layers are made of any one of epoxy, melamine, parylene, water glass, polypropylene (PP), polyethylene (PE) and polyamide (PI). Method of manufacturing an antenna. 18. The method of claim 17, wherein the first and second patterns are formed of any one of a conductive paste made of a metal powder and an organic binder, a conductive polymer, and a conductive metal thin film. 18. The method of claim 17, further comprising forming first and second terminal pads connected to both terminals of the first and second patterns on one side of the magnetic sheet. 18. The method of claim 17, wherein the thickness of the first insulating layer is set in a range of 1 to 50 um. 18. The method of claim 17, wherein the total thickness of the RFID antenna is set in a range of 0.15 to 0.3 mm. delete delete delete delete delete

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