JP2008310604A - Ic card for common use in contact/noncontact antenna sheet and manufacturing method for antenna sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce antenna resistance as a whole including the connecting part between an IC chip and an antenna by using different antenna metal materials for the front and the back, and also to reduce the constraint by the antenna during card processing. <P>SOLUTION: This IC card has a terminal board on the outer surface. In an IC card for common use, the two terminals 7a and 7b for antenna connection of an IC module 5 on which an IC chip for common use in contact/noncontact is mounted, a substrate having two terminals 7a and 7b for antenna connection on the inner surface thereof, and an antenna starting end part 21 and an ending end part 22 in a card substrate 10 are connected in a concave part 30 for mounting IC module. An antenna pattern is formed on the front and the back of the antenna sheet 20. On the side surface which has the antenna starting end part 21 and the ending end part 22, metal materials whose connection resistance with a conductive connecting material is smaller than that of the opposite side surface of the antenna sheet is used. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a contact / non-contact common type IC card (also referred to as “dual interface IC card” or “combination type”) and an antenna sheet used therefor. The contact / non-contact type IC card is exposed to the air when a part of the antenna appears in the recess excavated for mounting the IC module when the IC module is mounted. There is a problem that the connection resistance increases. Therefore, in the present invention, antenna patterns embedded in the card base are formed on both sides of the antenna sheet, and the metal on the IC module side uses a metal having a low connection resistance with the conductive connection material, and the back side is different. It is characterized by using materials.

The IC card is a contact type IC card that performs data communication via a connection terminal on the card surface, a non-contact type in which an IC chip and a communication antenna coil are embedded in the card base, and there is no terminal on the card surface. There are three types of contact and non-contact type that have functions.
Of these, the contact / non-contact common type is connected to a predetermined pad of a chip for connecting to the antenna pattern end (usually two places) on the back side of the IC module (the back side of the terminal board for connecting the external device of the IC module). The antenna connection terminal is provided and is connected to the end of the antenna pattern exposed in the recessed portion for embedding the IC module excavated in the card via a conductive adhesive or conductive sheet. A function as a card is provided.

  By the way, as a manufacturing feature of this contact / non-contact type IC card, a predetermined IC module is embedded in a card base in which an antenna sheet having an antenna formed in advance is embedded, antenna both ends, and an IC module antenna connection terminal. IC module mounting recesses for electrical connection (conduction) with the card, and for the latter purpose, both ends (start end and end end) of the antenna pattern in which the card is once embedded in the base ) Must be exposed to the outside.

  However, if the antenna component is a metal that is easily oxidized, an oxide film is formed on the surface immediately after being exposed to the air. In the state where the characteristics have been lost, sufficient conduction between the IC module and the antenna cannot be achieved even if the subsequent steps (conductive paste application step, IC module thermal pressure mechanical and electrical bonding step) are performed. Usually, copper having a small influence of an oxide film is usually selected as the antenna member.

  In a non-contact IC card (non-contact single-function IC card) in which the antenna is not exposed on the surface, not only copper but also aluminum having a relatively low electrical resistance value is used as an antenna member. Although there are many examples, there is a problem that it is difficult to select aluminum for the above-mentioned reason for a contact / non-contact common type IC card.

  In addition, there is a method of applying an antioxidant to the aluminum surface or performing metal plating (for example, gold) that does not oxidize on the surface. However, as described above, the cutting depth when the antenna end is exposed by cutting processing is also available. That is, the depth position in the thickness direction at which the antenna end is exposed is not constant, and is likely to vary due to the thickness error of each layer of the card substrate, the thickness error of the antenna member, the error of the cutting depth, and the like. Therefore, even if anti-oxidation measures are taken only on the surface of the antenna member, there is no confirmation that the portion exposed by cutting is the outermost surface of the end of the antenna pattern, and oxidation proceeds immediately if a portion deeper than the outermost surface is exposed. As a result, an oxide film is formed. In other words, this method cannot provide an effect.

  When a conductive adhesive is used as a connection agent between electrodes, the measured resistance is the resistance of the conductive adhesive itself and the connection resistance (contact) generated at the contact interface between the adherend (electrode material) and the conductive adhesive. Resistance). Accordingly, it is important that not only the volume resistivity of the conductive adhesive is low but also the connection resistance with the adherend is low.

As described in Non-Patent Document 1, connection resistances (mΩ) between various conductive adhesives and various substrates are as shown in Table 1. According to Table 1, when the silver paste is used, the aluminum substrate has a very high connection resistance value such that the aluminum substrate has a resistance of 6000 mΩ and the copper substrate has a resistance of 0.33 mΩ. However, although the reason is not clear, the numerical value is reversed in the carbon paste. Therefore, it cannot always be said that aluminum has a large connection resistance compared to copper. It means the connection resistance found empirically.
In addition, according to the Chemical Handbook Basic Edition (issued on August 20, 1978, page 1155), the specific resistance of aluminum is 2.75 × 10 ⁻⁶ Ωcm, and copper is 1.72 × 10 ⁻⁶ Ωcm ( Since both are 20 ° C.), the specific resistance of the metal itself is not so different. Thereby, it can be inferred that the connection resistance is increased by the metal oxide film.
Table 2 shows the volume resistivity values (ρ) of various conductive adhesives, and the silver paste shows a small volume resistivity value of 1.1 × 10 ⁻⁴ Ω · m. Table 2 is also cited from Non-Patent Document 1.

  Regarding the antenna and antenna sheet of a non-contact IC card and a shared IC card, there are many prior documents besides Patent Document 1, Patent Document 2, etc., but an example using different types of antenna metals cannot be found. Patent Document 2 is an antenna sheet of a non-contact single function IC card. Patent Document 3 relates to a prior patent document relating to a contact-type non-contact-type shared IC card and a manufacturing method thereof.

Japanese Patent Laying-Open No. 2005-45161 JP 2005-275502 A JP 2000-182017 A ThreeBond "Technical News" issued on January 1, 1999 Number 52

In order to solve the above-described problems, the present invention uses a metal material having a small connection resistance to the conductive connection material for the antenna start end and end portion side members exposed to the surface by cutting, and other antenna patterns. Another metal material is used for the member, that is, the antenna pattern end and the other part are made of different kinds of metal members.
However, as a manufacturing method, it is actually difficult to manufacture using different metal materials only at both ends of the antenna pattern. Therefore, different metal materials are laminated separately on the front and back sides of the antenna sheet. To use.

  A first invention for solving the above problem is an IC module in which a contact / non-contact IC chip is mounted on a substrate having an external device connection terminal plate on the outer surface and two antenna connection terminals on the inner surface. A contact / non-contact type IC having a structure in which the two antenna connection terminals and the start and end portions of the antenna pattern in the card base are connected to each other through a conductive connection material in the recess for mounting the IC module. In the card, the antenna pattern is formed on the front and back of the antenna sheet, and the conductive pattern is connected to the side of the antenna pattern where the start and end portions are located rather than the antenna pattern on the opposite side of the antenna sheet. A contact / non-contact IC card characterized by using a metal material with low resistance.

  In the contact / non-contact type IC card, a metal material having a higher Young's modulus than the metal material on the opposite side of the antenna sheet can be used for the metal material on the side where the antenna pattern starts and ends. In such a case, the Young's modulus of the metal material on the side where the majority of the antenna coil is present becomes small, and it can be made difficult to break against elongation deformation. Also, in practice, copper is used for the antenna metal material on the surface of the antenna sheet where the antenna pattern has the start and end portions, and aluminum is used for the antenna pattern on the other surface of the antenna sheet. Can do. Furthermore, the metal material portions having different front and back surfaces of the antenna pattern can be electrically connected by any one of plating, resistance welding, ultrasonic connection, conductive adhesive, and crimping.

  A second invention for solving the above-mentioned problem is an IC module in which a contact / non-contact IC chip is mounted on a substrate having an external device connection terminal plate on the outer surface and two antenna connection terminals on the inner surface. A contact / non-contact type IC having a structure in which the two antenna connection terminals and the start and end portions of the antenna pattern in the card base are connected to each other through a conductive connection material in the recess for mounting the IC module. In the antenna sheet used for the card, a metal material having a lower connection resistance with the conductive connection material than the antenna pattern portion on the opposite side surface of the antenna sheet is used on the side surface where the antenna pattern starts and ends. The antenna sheet is characterized by that.

  In the antenna sheet, a metal material having a higher Young's modulus than the metal material on the opposite side of the antenna sheet can be used for the metal material on the side where the antenna pattern starts and ends. The Young's modulus of the metal material on the side where the majority of the antenna coil is present can be reduced, making it difficult to break against elongation deformation. Also, in practice, copper is used for the antenna metal material on the surface of the antenna sheet where the antenna pattern has the start and end portions, and aluminum is used for the antenna pattern on the other surface of the antenna sheet. Can do. Furthermore, the metal material portions having different front and back surfaces of the antenna pattern can be electrically connected by any one of plating, resistance welding, ultrasonic connection, conductive adhesive, and crimping.

3rd invention which solves the said subject is the foil of the metal material (A metal) with small connection resistance with a conductive connection material on the single side | surface of the following (1)-(5), and (1) antenna base sheet. And laminating a foil of a metal material (B metal) having a larger connection resistance with the conductive connection material than the metal material on the other surface, and (2) an antenna on the surface of the A metal foil on one side. Forming a resist film of an antenna pattern including a start end, a termination, and a part of an antenna coil;
(3) forming a resist film of an antenna pattern including the remaining portion of the antenna coil on the surface of the B metal foil on the other surface; (4) corroding the metal foil on both surfaces with an etching solution;
(5) A method for manufacturing an antenna sheet, comprising a step of connecting the antenna patterns on the front and back sides in at least two places.

  In the above, a metal material having a higher Young's modulus than the metal material (B metal) on the side surface opposite to the antenna sheet can be used for the metal material (A metal) on the side surface having the start and end portions of the antenna pattern. In such a case, the Young's modulus of the metal material on the side where the majority of the antenna coil is present becomes small, and it can be made difficult to break against elongation deformation. In practice, the A metal can be copper and the B metal can be aluminum.

  In the contact / non-contact type IC card according to claim 1, a metal material having a lower connection resistance to the conductive connection material than the metal material on the opposite side of the antenna sheet is used at both ends of the antenna connected to the IC module. Therefore, the resistance of the IC card antenna as a whole including the connection portion between the IC chip and the antenna can be reduced.

  In the contact / non-contact type IC card according to claim 2, a material having a higher Young's modulus than the metal material on the opposite side of the antenna sheet is used as the metal material on the side where the antenna pattern starts and ends. Can do. In such a case, the Young's modulus of the metal material on the side where most of the antenna coil is present is reduced, and the antenna coil can be made difficult to break against elongation deformation. Further, even when post-processing such as embossing overlaps with the antenna portion, it is difficult to disconnect, and restrictions during post-processing can be reduced.

In the contact / non-contact type IC card according to claim 3, both ends of the antenna connected to the IC module use copper having a low connection resistance with the conductive connection material, and the other side of the antenna sheet other than the portion is used. Since aluminum is used, the resistance of the IC card antenna as a whole including the connection portion between the IC chip and the antenna can be reduced. Moreover, aluminum can be used in addition to both ends of the antenna pattern, and the extensibility of the antenna is greater than when copper is used, and the restrictions imposed by the antenna during post-card processing can be reduced.
In the contact / non-contact type IC card according to claim 3, when a material having a small connection resistance with the conductive connection material is used for the whole antenna, for example, when copper is used for the whole, it leads to waste of rare resources. There is a problem, but the problem can be alleviated by using aluminum together.
In the contact / non-contact type IC card according to claim 4, it is possible to connect the metal material portions having different front and back surfaces without reducing the connection resistance and increasing the thickness of the connection portion.

The antenna sheet according to claims 5, 6, 7 and 8 can be used for an IC card to obtain the same effect as described above.
According to the manufacturing method of the antenna sheet of the ninth, tenth, and eleventh aspects, an antenna sheet having low connection resistance and excellent characteristics can be obtained at low cost by using different metal materials for the front and back of the antenna base sheet.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of an antenna sheet according to the present invention, FIG. 2 is a diagram illustrating another example of an antenna sheet, and FIG. 3 is a plan view illustrating a contact / non-contact shared IC card according to the present invention. 4 is a partial cross-sectional view of a contact / non-contact IC card, FIG. 5 is a diagram showing an example of a contact / non-contact IC module, and FIG. 6 is a contact / non-contact IC of the present invention. FIG. 7 is a diagram for explaining an example of a conventional antenna sheet.

Prior to describing the antenna sheet of the present invention, a conventional antenna sheet will be described.
FIG. 7 is a diagram illustrating an example of a conventional antenna sheet. Originally, it consists of a fine pattern as shown in each figure of Patent Document 2, but the components of the antenna are conceptually illustrated. Therefore, the actual shape is not shown. In FIG. 7, a solid line indicates a pattern or wiring on the front side of the base sheet 11, and a hatched portion indicates a pattern or the like on the back side of the base sheet 11.
In the conventional antenna sheet 20j, the antenna pattern 2 is formed on the surface of a base sheet 11 made of a plastic film such as polyethylene terephthalate (PET).

The antenna pattern 2 has an antenna start end portion 21 and a terminal end portion 22, and an antenna coil portion 27, capacitor patterns 23 and 24, and front and back wiring connection portions 25 and 26 between both ends thereof. Either one of the two end portions 21 and 22 of the antenna may be considered as the start end portion 21 or the end portion 22. The both ends 21 and 22 can be connected to two antenna connection terminals of the IC module.
Normally, the capacitor pattern is composed of a set of a plurality of small patterns, and the capacitance can be adjusted by sequentially cutting the capacitors of the small pattern. In the case of FIG. Is expressed. The front and back capacitor patterns 23 and 24 are actually substantially the same size, and a capacitor is formed via a base sheet 11 that is a dielectric. The purpose of cutting and adjusting is to adjust the resonance frequency by changing the capacitance of the capacitor. As is clear from the above description, the antenna pattern 2 includes the antenna start end portion 21 and the termination portion 22, the capacitor patterns 23 and 24, the antenna coil portion 27, the front and back wiring connection portions 25 and 26, and the like.

In the case of FIG. 7, most of the antenna pattern 2 including the coil portion is formed on the surface side of the base sheet 11, and only the capacitor pattern 24 between the front and back wiring connection portions 25 and 26 and its connection circuit are provided on the base sheet 11. It is formed on the back side. For the antenna pattern 2, it is normal to use a copper foil for the reason described above. Such an antenna sheet 20j is obtained by laminating copper foil on both surfaces of the base sheet 11, coating a photosensitive resin material on the copper foil surface, exposing and developing an antenna pattern made of a photomask, etching, and etching. To manufacture.
Before patterning the antenna, a copper foil having a thickness of about 35 μm is laminated on both sides of the base sheet 11, and most of the copper foil is dissolved by etching. Since copper is used on the entire surface, there is a problem of consuming precious resources.

FIG. 1 is a diagram illustrating an example of an antenna sheet 20 according to the present invention. Similarly to FIG. 7, the solid line indicates the wiring or pattern on the front surface side of the base sheet 11, and the hatched portion indicates the wiring or pattern on the back surface side of the base sheet 11. The same is true for conceptual illustration.
Also in the case of FIG. 1, the antenna has an antenna start end portion 21 and a terminal end portion 22 on the front surface side, and an antenna coil portion 27, front and back capacitor patterns 23 and 24, and front and back wiring connection portions 25 and 26 between the both end portions. is doing. The IC module is mounted on the antenna start end 21 and the terminal end 22. In the case of FIG. 1, the antenna start end portion 21, the end portion 22, and the capacitor pattern 23 are formed on the surface side of the base sheet 11, and most of the antenna coil portion 27 (range of 90% to 100% of the total length of the antenna). The capacitor pattern 24 is formed on the back side of the base sheet 11. However, the antenna start end portion 21 and the termination portion 22 may be on the back surface side, and the antenna coil portion 27 may be on the front surface side. In addition, in FIG. 1, although the single antenna sheet | seat 20 is shown in figure, it is normally used in the state of multiple imposition in a manufacturing process.

  FIG. 2 is a diagram illustrating another example of the antenna sheet 20 of the present invention. The illustrated method is the same as that shown in FIGS. Also in the case of FIG. 2, it has an antenna start end portion 21 and a termination portion 22 on the surface side, and has a coil portion, front and back capacitor patterns 23 and 24, and front and back wiring connection portions 25 and 26 between both end portions, The capacitor pattern 23 is formed on the front surface side of the base sheet 11, and most of the antenna coil portion 27 (in the range of 60% to 90% of the total length of the antenna) and the capacitor pattern 24 are formed on the back surface side of the base sheet 11. . 1 differs from the case of FIG. 1 in that a part of the antenna coil portion 27 is formed on the front surface side and both the front and back wiring connection portions 25 and 26 that are connection portions of the front and back patterns are separated from the IC module mounting portion. It is in a position (preferably about 10 mm or more away from the terminal board of the IC module). In the case of FIG. 1, the front and back wiring connection portion 25 on one side is located in a narrow area between the terminal board of the IC module and the edge of the card.

  In general, since the total thickness of the card is large at the front and back wiring connection portions, a step is likely to occur, and there is a problem that the terminal board of the IC module tends to be inclined when the portion is located near the IC module. In the embodiment of FIG. 2, both the front and back wiring connection portions 25 and 26 are arranged at locations away from the IC module mounting portion, and thus there is an advantage that the connection between the IC module and the antenna end is stabilized.

The feature of the antenna sheet 20 of the present invention is that the antenna pattern is formed on the front and back sides of the antenna sheet, and the side surface having the start end portion and the end portion of the antenna pattern is more than the antenna pattern portion on the opposite side surface of the antenna sheet. A metal material having a small connection resistance with the conductive connection material is used. As a result, there is an effect that the resistance of the IC card antenna as a whole including the connection portion between the IC chip and the antenna can be reduced.
Further, a material having a higher Young's modulus (elongation elastic modulus) than the metal material on the opposite side of the antenna sheet can be used as the metal material on the side where the antenna pattern has the start end and the end. In such a case, a material having a small Young's modulus is used for the metal material on the side where the majority of the antenna coil is present, and the antenna coil can be hardly broken against elongation deformation. Arise.

Such a practical and versatile material that meets the purpose includes copper as a material having a low connection resistance, and aluminum as a material having a low Young's modulus. These foils are used in combination for the antenna sheet. Note that copper is not limited to pure copper but also includes alloys containing copper as a main component. The same applies to aluminum.
By the way, as "aluminum Handbook"Young's modulus of the metal is in (Japan Aluminum Association issued), copper: 129.8kN / mm ^2, aluminum: there is a description of 70.6kN / mm ^2. The above-mentioned chemical handbook basic edition (page 564) also has the same numerical values.

  FIG. 3 is a plan view for explaining the contact / non-contact IC card 1 of the present invention. In the plan view of FIG. 3, since it is a contact / non-contact IC card, the external device connection terminal board 4 is provided on the card surface, but the terminal board surface pattern shape and the like are omitted. A chain line displayed around the card means that the antenna pattern 2 exists inside the card base 10.

The antenna start end portion 21 and the terminal end portion 22 are formed so as to face the IC module mounting portion in order to connect both ends of the antenna pattern 2 and the antenna connection terminals 7a and 7b (see FIG. 4) of the IC module 5. In the contact / non-contact type IC card 1 of the present invention, in order to ensure the electrical conductivity and adhesive strength between the antenna start end 21 and the end end 22, the same is true in the normal case, but both ends of the antenna pattern have a large area. It is preferable to be formed. In order to ensure sufficient strength, it is preferable that the total area (A) of the antenna start end 21 and the end end 22 in the IC module mounting recess is 3 mm ² or more. Therefore, the IC module side antenna connection terminals 7a and 7b connected to the antenna pattern are preferably formed in a large area, and the total area (a) of the antenna connection terminals 7a and 7b is 3 mm ² or more. Is preferred. The reason why the area is 3 mm ² or more is that if the area is 3 mm ² or less, sufficient adhesive strength may not be obtained in any case.

  FIG. 4 is a partial cross-sectional view of the contact / non-contact type IC card 1 and shows a mounting portion of the IC module 5. As shown in FIG. 4, in this embodiment, the card base 10 of the contact / non-contact type IC card 1 is composed of seven layers of an antenna base sheet 11, adhesive sheets 12 and 13, core sheets 14 and 15, and oversheets 16 and 17. It is configured. However, the card base 10 is not limited to the seven-layer configuration. In this embodiment, the IC module mounting recess 30 is formed to have a two-stage depth, and the first recess 31 is excavated to the substrate thickness of the IC module 5. A part of the first recess 31 is further excavated to a depth at which the antenna start end 21 and the end end 22 are exposed. The second recess 32 is formed to a depth at which the mold resin portion 8 of the IC module 5 can be embedded. However, the concave shape of the module mounting portion is not limited to two steps, and a groove may be provided on the outer peripheral portion. In some cases, the depth of the first recess 31 is substantially equal to the thickness of the oversheet 16.

As shown in FIG. 4, the first recess 31 is cut so that the antenna start end portion 21 and the terminal end portion 22 are exposed on the surface. In this cutting, the base material thickness calculated in advance by NC processing or the like is cut from the card surface. Preferably, the cutting amount may be controlled by detecting the antenna portion with a metal sensor. The second recess 32 is cut to a depth that allows the molding resin portion 8 of the IC module 5 to be embedded. Next, after applying the conductive adhesive 9 to the antenna start end 21 and the terminal end 22, the IC module 5 is mounted and heated and pressurized.
Thereby, the antenna connection terminals 7a and 7b on the IC module 5 side and the antenna both end portions (antenna start end portion 21 and termination end portion 22) on the card base side are electrically connected via the conductive adhesive 9. In addition, the IC module 5 can be fixed to the card base 10.

  In this case, the IC module 5 may be fixed to the first recess 31 of the IC module mounting recess 30 using only a conductive adhesive or a conductive adhesive sheet. The conductive adhesive and the insulating adhesive (or the adhesive) The IC module 5 may be fixed by using a sheet together.

  Since the contact / non-contact IC card of the present invention uses the antenna sheet of the present invention, it has the features and effects of the antenna sheet as they are. That is, since the resistance of the IC card antenna as a whole including the connection portion between the IC chip and the antenna can be reduced, the non-contact communication distance is increased, and the durability against the extension deformation of the antenna coil is increased. The reliability of the card can be increased. Further, it is possible to reduce manufacturing costs and resources.

  FIG. 5 is a view showing an example of a contact / non-contact type IC module. FIG. 5 (A) shows the surface side of the external device connection terminal board 4, and FIG. 5 (B) shows the mold resin portion 8. The back side is shown. The cross section can be inferred from FIG. As usual, the surface of the IC module 5 has eight terminal boards C1 to C8. The contact / non-contact type IC chip 3 is characterized by having C9 and C10 pads for non-contact interface on the back side. The pads C9 and C10 are connected to the two antenna connection terminals 7a and 7b by bonding wires 18. Of course, pads having other functions are also not shown. The IC chip 3 and the wire part are resin-sealed to form a mold resin part 8.

Next, a method for manufacturing the antenna sheet will be described.
First, a metal material (A metal) foil having a low connection resistance to the conductive connection material is laminated on one surface of the antenna base sheet, and a metal material (extensive and / or malleable than the metal material) on the other surface ( B foil) is laminated. Usually, it is laminated on almost the entire surface of the base sheet, but an expensive metal material may be partially laminated in a strip shape. In the case of a contact / non-contact type IC card, typically, copper (Cu) is recommended as the A metal, and aluminum (Al) can be used as the B metal. A metal foil material (thickness of about 15 μm to 50 μm) is laminated with an adhesive having a thickness of about 1 μm to 20 μm.
The antenna base sheet 11 can employ various materials in addition to polyimide, PET, and PEN (polyethylene naphthalate). For example, vinyl chloride resin, PET-G, polypropylene resin, polycarbonate resin, acrylic resin, polystyrene resin, ABS resin, polyamide resin, polyacetal resin and the like can be mentioned.

Next, a resist film for the antenna pattern 2 including the antenna start end portion 21, the termination portion 22, a part of the antenna coil portion 27, and the capacitor pattern 23 is formed on the surface of the A metal foil on one side. Further, a resist film for the antenna pattern 2 including the remaining portion of the antenna coil portion 27 and the capacitor pattern 24 is formed on the surface of the B metal foil on the other surface. In this step, a photoresist may be used, or a resist pattern may be printed.
The metal foil on both sides is etched using the resist film as a corrosion resistant film. In the case of metal materials having different front and back surfaces, it is generally difficult to etch simultaneously. In the case of copper, iron chloride (ferric chloride) is generally used. However, in the case of an aluminum material, an etching solution containing a concentrated phosphoric acid solution as a main component and an appropriate amount of nitric acid is generally used. Alkaline solution also dissolves aluminum, but it is not used industrially because of the reaction heat and resist resistance. In the case of simultaneous etching, the other side surface not etched is covered with a protective coating film and etched. However, if copper and aluminum are used, simultaneous etching with iron chloride (ferric chloride) is possible.

  After the front and back etching, the resist is peeled off and washed, and then the front and back antenna patterns are connected. This requires at least two connections. After forming a small-diameter opening (diameter of about 0.2 mm) so as to penetrate the metal foils on both sides and the antenna base sheet 11, the metal foils on the front and back sides are connected by plating or conductive adhesive, or resistance welding, The connection is made by either ultrasonic connection or crimping without forming an opening. In the case of plating, electroless plating with copper or the like is performed, followed by nickel (Ni) base plating and gold (Au) plating. Resistance welding is a method in which an electric current is passed through the joints, the temperature of the joint is increased by resistance heat generated by the current, and the joints are joined under pressure.

The ultrasonic connection is a method in which connection is made by applying ultrasonic vibration while overlapping and pressing a material to be connected and sandwiching and pressing between a welding tip and a lower base. As the temperature rises due to frictional heat, the contact area approaches to the extent that interatomic attractive force acts between the connection surfaces, and the connection area increases. When the ultrasonic connection method is adopted, the connection interface becomes an alloy layer of copper and aluminum, and a stable connection can be obtained.
In the case of a conductive adhesive, what contains silver (Ag) or copper (Cu) as conductive particles is often used by printing or the like.
Crimping is a method of joining by physically distorting and joining the parts to be joined.

  In general, a plating method is often used. However, in an IC card antenna, the number of connection portions is small and the cost is increased, so that other methods are often used. In the case of dissimilar metals, for example, Cu / Al connection as in the present invention, the use of a conductive adhesive increases the connection resistance. In the case of resistance welding, it is difficult to use suitable conditions for both Cu and Al. Connection or connection by crimping is preferable. In connection with ultrasonic waves and crimping, connection resistance hardly occurs.

Next, a method for manufacturing a contact / non-contact type IC card will be described.
FIG. 6 is a diagram for explaining a manufacturing process of a contact / non-contact type IC card. The antenna sheet 20 shown in FIG. 6 is different from that shown in FIG. 1 in that the antenna coil portion 27 is provided on the front surface side (core sheet 14 side) and the antenna start terminal 21 and the terminal portion 22 are provided on the back surface side. As described above, processing is possible regardless of which side the antenna start end portion 21 and the end end portion 22 are on, and only a change in excavation depth causes no difference in performance.
First, as shown in FIG. 6A, an antenna sheet such as PET or PEN in which the antenna start end portion 21 and the terminal end portion 22 of the antenna pattern 2, the antenna coil portion 27, and the capacitor patterns 23 and 24 are manufactured by photoetching or the like. 20 is prepared as described above.

FIG. 6 shows a case where a biaxially stretched PET sheet is used as the base sheet 11 of the antenna sheet 20. In this case, the antenna sheet 20 and the core sheets 14 and 15 are laminated using an adhesive sheet. However, the adhesive sheet is not shown in FIG.
Next, the core sheets 14 and 15 and the oversheets 16 and 17 are temporarily stacked and laminated thereon, and then hot-pressed to produce an integrated card base (FIG. 6B). When PET-G is used for both the core sheets 14 and 15 and the oversheets 16 and 17, since the two are heat-sealed, it is not necessary to use an adhesive sheet therebetween. This process is performed in a multi-faceted state.
In addition to the vinyl chloride resin, PET, and PET-G, various materials can be used for the card base 10, such as polypropylene resin, polycarbonate resin, acrylic resin, polystyrene resin, ABS resin, polyamide resin, polyacetal resin, and the like. Is mentioned.

  Thereafter, after cutting into individual cards, the first recess 31 for mounting the IC module 5 is cut to expose the surfaces of the antenna start end portion 21 and the end portion 22 in the card base 10. It is preferable to expose the surface so as not to cut both ends of the antenna as much as possible. Further, the second concave portion 32 having a depth and a size capable of embedding the mold resin portion 8 of the IC module 5 is cut to substantially the center of the first concave portion 31 (FIG. 6C).

Next, the chip-side antenna connection terminals 7 a and 7 b provided in the IC module 5 are connected to the antenna start end 21 and the end end 22 on the card base 10 side by the conductive adhesive 9. For this purpose, a conductive adhesive 9 such as a silver paste is applied as a connecting agent on the antenna start end 21 and terminal end 22 (FIG. 6D). This application region is divided into at least two regions so as not to cause a short circuit. Further, an insulating adhesive sheet may be attached to a portion other than the conductive adhesive application region on the antenna connection terminal of the IC module 5.
After the application of the conductive adhesive 9, the IC module 5 is mounted and heat pressure (for example, 200 ° C., 1 second) is applied to bond the IC module 5 to the card base 10 and to electrically connect the antenna pattern 2. Connect. In the case of a room temperature curable adhesive, it can be cured by leaving it for a relatively long time near room temperature without heating. Thereby, the contact / non-contact type shared IC card 1 of the present invention is completed (FIG. 6E).

  As the conductive adhesive 9, a silver paste or solder can be used, and a conductive adhesive sheet, an anisotropic conductive sheet, an anisotropic conductive paste, or the like can be used. The adhesive may be applied on the antenna connection terminal on the card base 10 side or on the IC module side antenna connection terminals 7a and 7b. Moreover, various adhesives and adhesive sheets, such as a thermosetting type and a thermoplastic type, can be used for the insulating adhesive.

Examples of the contact / non-contact type IC card of the present invention and comparative examples will be described below.
A biaxially stretched PET sheet with a thickness of 38 μm was used as the antenna base sheet 11 of the card substrate 10, and a copper foil with a thickness of 35 μm was laminated on the front side thereof and an aluminum foil with a thickness of 35 μm on the back side with an adhesive. The antenna pattern 2 was formed on the base sheet 11 using a photo etching technique.
As shown in FIG. 2, the antenna sheet 20 has an antenna start end portion 21, a termination portion 22, and a capacitor pattern 23 on the surface side (core sheet 14 side) of the base sheet 11, and the back surface side (core sheet 15 side). The antenna coil portion 27 and the capacitor pattern 24 are provided. The front and back wirings of the base sheet 11 are ultrasonically connected through two front and back wiring connection portions 25 and 26. The front and back wiring connection portions 25, 26 are formed on the right side of the card base 10 so as not to approach the mounting portion of the IC module 5.

  Core sheets 14 and 15 made of a PET-G resin sheet having a thickness of 280 μm are laminated on the front and back of the antenna sheet 20 via polyester hot-melt adhesive sheets 12 and 13 having a thickness of 50 μm, and further on the outer side. PET-G sheets having a thickness of 50 μm were used as the oversheets 16 and 17. After these sheets were temporarily stacked, they were placed on a hot plate of a press machine and press laminated. The conditions for the pressing process were a hot plate temperature of 120 ° C., a pressure of 2.0 MPa, and a molding (heating) time of 20 minutes. The total thickness of the card substrate 10 was 800 μm.

  After cutting into individual card sizes, the IC module mounting recess 30 was cut into the antenna base embedded card base 10, and the first recess 31 was cut to a depth at which the antenna start end 21 and terminal end 22 appeared by NC processing. Subsequently, the second recess 32 was further excavated between the antenna pattern terminals to such a depth that the mold resin portion of the IC module 5 was sufficiently embedded.

  On the other hand, copper foil is separately attached to both surfaces of the glass epoxy substrate, photoetching is performed to form the external device connection terminal plate 4 on the front surface, and antenna connection terminals 7a and 7b, one of which is 2.0 mm on the back surface. Two locations were formed so as to have a size of × 3.0 mm. The terminal part was plated with nickel and gold. After mounting the contact / non-contact type IC chip 3 on the module substrate 6, the external device connection terminal plate 4 and the antenna connection terminals 7a and 7b are connected by a gold wire through wire bonding and through holes, Further, the periphery of the IC chip was sealed with an epoxy resin. Thereby, the IC module 5 was completed.

  A conductive adhesive made of silver paste is applied to the antenna start end 21 and terminal end 22 of the card base 10, and the IC module 5 prepared as described above is mounted, and then fixed by heating and pressing at 200 ° C. for 1 second. Thus, the contact / non-contact IC card 1 was completed.

[Comparative example]
As the base sheet 11 of the antenna sheet 20, the same biaxially stretched PET sheet having a thickness of 38 μm as in the example was used. Except for laminating 35 μm aluminum foil of the same thickness as that of the example on both sides and manufacturing and using the antenna sheet 20j of FIG. Completed contact sharing type IC card 1.

  When the communication distance of the contact / non-contact type IC card 1 of the example and the comparative example was measured using the same reader / writer, in the case of the comparative example using the double-sided aluminum foil, the communication distance was about 10 mm. However, in the case of the example, a communication distance of about 25 mm could be secured.

It is a figure explaining the example of the antenna sheet | seat of this invention. It is a figure explaining the other example of an antenna sheet. It is a top view explaining the contact / non-contact shared type IC card of this invention. It is a fragmentary sectional view of a contact / non-contact shared IC card. It is a figure which shows the example of a contact / non-contact shared type IC module. It is a figure explaining the manufacturing process of the contact / non-contact shared type IC card of this invention. It is a figure explaining the example of the conventional antenna sheet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Contact / non-contact common type IC card 2 Antenna pattern 3 Contact / non-contact common type IC chip 4 External device connection terminal board 5 IC module 6 Module board 7a, 7b Antenna connection terminal 8 Mold resin part 9 Conductive adhesive 10 Card Base 11 Antenna Base Sheet 12, 13 Adhesive Sheet 14, 15 Core Sheet 16, 17 Over Sheet 20 Antenna Sheet 21 Antenna Start End 22 Antenna Termination 23, 24 Capacitor Patterns 25, 26 Front / Back Wiring Connection 27 Antenna Coil 30 IC module mounting recess 31 First recess 32 Second recess

Claims (11)

  The two antenna connection terminals of the IC module in which a contact / non-contact IC chip is mounted on a substrate having an external device connection terminal plate on the outer surface and two antenna connection terminals on the inner surface; In a contact / non-contact type IC card having a structure in which the start end and the end of the antenna pattern in the body are connected via a conductive connection material in the recess for mounting the IC module, the antenna pattern is placed on the front and back of the antenna sheet. A metal material having a smaller connection resistance to the conductive connection material than the antenna pattern portion on the opposite side surface of the antenna sheet is used for the side surface where the antenna pattern has a start end and a terminal end. A contact / non-contact IC card.   The contact / non-contact common use according to claim 1, wherein a metal material having a higher Young's modulus than the metal material on the opposite side of the antenna sheet is used as the metal material on the side having the start and end portions of the antenna pattern. IC card.   The antenna metal material on the side where the antenna pattern of the antenna sheet has the start end portion and the end portion is made of copper, and the antenna pattern portion on the other side of the antenna sheet is made of aluminum. The contact / non-contact type IC card according to claim 1 or 2.   The metal material portions having different front and back surfaces of the antenna pattern are electrically connected by any one of plating, resistance welding, ultrasonic connection, conductive adhesive, and crimping. The contact / non-contact type IC card according to claim 3.   The two antenna connection terminals of the IC module in which a contact / non-contact IC chip is mounted on a substrate having an external device connection terminal plate on the outer surface and two antenna connection terminals on the inner surface; In an antenna sheet used for a contact / non-contact shared IC card having a structure in which a start end and a terminal end of an antenna pattern in a body are connected via a conductive connection material in a recess for mounting an IC module, the antenna pattern An antenna sheet characterized in that a metal material having a smaller connection resistance with the conductive connection material than the antenna pattern portion on the opposite side surface of the antenna sheet is used on the side surface having the starting end portion and the terminal end portion.   6. The antenna sheet according to claim 5, wherein a material having a higher Young's modulus than that of the metal material on the opposite side of the antenna sheet is used as the metal material on the side having the start end and the end of the antenna pattern.   The antenna metal material on the side where the antenna pattern of the antenna sheet has the start end portion and the end portion is made of copper, and the antenna pattern portion on the other side of the antenna sheet is made of aluminum. The antenna sheet according to claim 5 or 6.   The material parts of the antenna pattern having different front and back surfaces are electrically connected by any one of plating, resistance welding, ultrasonic connection, conductive adhesive, and crimping. The antenna sheet according to claim 7. The following steps (1) to (5);
(1) A foil of a metal material (A metal) having a low connection resistance with the conductive connection material is laminated on one surface of the antenna base sheet, and the connection resistance with the conductive connection material is higher than that of the metal material on the other surface. A step of laminating a foil of metal material (B metal), and (2) a step of forming an antenna pattern resist film including an antenna start end portion, a terminal end portion and a part of an antenna coil on the surface of the A metal foil on one side. ,
(3) forming a resist film of an antenna pattern including the remaining portion of the antenna coil on the surface of the B metal foil of the other surface;
(4) The process of corroding the metal foil on both sides with an etching solution,
(5) A method of manufacturing an antenna sheet, comprising a step of connecting the antenna patterns on the front and back sides in at least two places.   The material having a higher Young's modulus than the metal material (B metal) on the opposite side surface of the antenna sheet is used for the metal material (A metal) on the side surface having the start and end portions of the antenna pattern. 9. A method for producing the antenna sheet according to 9.   The method for manufacturing an antenna sheet according to claim 9 or 10, wherein the A metal is copper and the B metal is aluminum.

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