JPH09260812A - Printed circuit board for radio ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide higher functions and higher capacity by making a circuit board thinner and using compact electronic parts such as IC by using two- layered printed circuit boards with each layer provided with a conductive metal on a single surface or double surfaces of an insulation film without adhesion. SOLUTION: An insulation film 1 with drilled through-holes is set to a sputtering device, and a nickel/copper vapor deposition film 3 is formed on both surfaces. After the vapor deposition, electric copper plating 4 is performed in a high-concentration copper sulfate plating bath, both surface are laminated with photosensitive dry films, and a circuit pattern is formed by exposing to ultraviolet ray by using a mask. Other than the connecting portions and electronic parts mounting portion of a circuit pattern are masked with a resist, and electroless nickel 5 and electroless gold 6 are applied to an exposed circuit pattern portion. By doing this, the function and capacity of electronic parts such as IC can be enhanced, and high reliability access can be obtained for leader and rider.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board for a wireless IC card composed of a two-layer type printed circuit board.

[0002]

2. Description of the Related Art An IC card is a plastic card containing an IC. Depending on its storage capacity, security, and ease of use, an IC card may be a cash card, a prepaid card or a prepaid card. It is widely used in credit cards. The IC card has a contact terminal for external connection exposed on the surface of the card, and a contact type terminal for controlling an interface with a terminal device and a memory access control via the terminal. There is a wireless type in which various connection terminals are housed in the IC card to control them wirelessly. The latter IC card allows speedy processing without the user having to insert the card into the connection terminal, and since there is no mechanical contact, there is no wear or damage, no moisture, Demand is expanding because it is less affected by wetting and dirt.

As shown in FIG. 1, a wireless IC card is composed of a printed circuit board and electronic components such as an IC module mounted on it, a battery, a protective film, etc., and the total thickness is JIS or ISO. 0.76mm according to the standard
Is being unified. The printed circuit board used for this is generally of the three-layer type in which a copper foil is bonded to a polyimide film on the market via an adhesive.

However, when the above-mentioned three-layer type is used, it cannot be said to be sufficient because of the following reasons. That is, all the electronic components such as the IC module are mounted within the total thickness of the IC card of 0.76 mm, and the printed circuit board itself is thinned in order to further improve the function and capacity. Is an essential condition. Further, since radio waves of several KHz to several thousand GHz are used for wireless access, the characteristics thereof are significantly affected by the dielectric constant, dielectric loss tangent and film thickness of the film forming the printed circuit board. In the conventional 3-layer type, the polymer of the film and the adhesive is different, so generally the dielectric constant of the polyimide film is 3.5 and the dielectric loss tangent is 0.002.
Is the dielectric constant 4.5 of the epoxy resin that is the adhesive
Unlike 0.01, the radio wave is attenuated and noise is generated between them, resulting in the lack of reliability of access by the reader and the rider. In addition, it is necessary to perform wire bonding of a gold wire at a high temperature of 400 ° C. or more in order to connect an IC chip and a circuit, and in the case of a three-layer type, the heat resistant temperature of an epoxy resin or an acrylic resin as an adhesive agent. Since the temperature is at most about 100 to 150 ° C., wire-bonding cannot be performed efficiently, resulting in a significant decrease in yield and a decrease in adhesion characteristics.

Japanese Unexamined Patent Publication No. 7-297524 discloses a low-cost printed wiring board for an IC card which is excellent in connection reliability of wire bonding and environment resistance, and a copper foil for a copper layer is bonded to an insulating substrate. Although a three-layer type in which the adhesive agent is used for adhesion is disclosed, it does not satisfy the total thickness and the access function due to the adhesive layer.

Further, Japanese Patent Application Laid-Open No. 7-266767 discloses a non-contact type IC card and a circuit board composed of a polyester resin film as a method for producing the same, which is an IC card.
It is a method for preventing the electronic parts from popping out from the battery and manufacturing it inexpensively and efficiently, and is not for solving the above defects.

[0007]

Therefore, according to the present invention, the printed circuit board can be made thin so as to have high functionality and high capacity by electronic parts such as ICs, and highly reliable wireless access is possible. A printed circuit board for an IC card is provided.

[0008]

According to the studies by the present inventors, the object of the present invention has been industrially advantageously achieved by the present invention described below. [1] A printed circuit board on which an IC module is mounted is composed of a two-layer type printed circuit board in which a layer made of a conductive metal is provided on one side or both sides of an insulating film having no adhesive layer. A printed circuit board for a wireless IC card.

[2] The polymer constituting the insulating film is polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyether ketone, aromatic polyamide, polyarylate, polyimide,
The printed circuit board for wireless IC card according to the above [1], which is a polymer selected from the group consisting of foliamide imide and polyether imide.

[3] The above-mentioned [1], wherein the layer made of a conductive metal is composed of a vapor-deposited layer made of copper or a copper alloy and a copper-plated layer which are sequentially formed when viewed from the side of the insulating film. Printed circuit board for wireless IC card.

[4] The two-layer type printed circuit board is characterized in that a vapor deposition layer made of a metal and ceramics and a layer made of a conductive metal are sequentially provided on an insulating film, and the above [1] to [3]. Printed circuit board for wireless IC card.

[5] The wireless type of the above [1], which is a metal-containing substance layer formed by chemical treatment in a layer aqueous solution of a conductive metal and a copper plating layer formed thereon. Printed circuit board for IC card.

[6] The printed circuit board for wireless IC card according to the above [1], wherein the insulating film is a polyimide film, and the layer made of a conductive metal is made of a copper foil.

[7] The wireless IC card according to the above [1], wherein the two-layer type printed circuit board is bonded to the copper plate by using an adhesive made of the same kind of polymer as that of the insulating film. Printed circuit board.

[8] The above [1] to [7], which are characterized in that they are formed by plating nickel, palladium, gold, tin, solder, platinum and their compounds on a layer made of a conductive metal. Printed circuit board for wireless IC card.

[9] The IC card of the above [1] to [8]
A wireless IC card created using a printed circuit board for a card.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The greatest point of the present invention is to use a two-layer type printed circuit board in which a conductive metal layer is provided on one side or both sides of an insulating film having no adhesive layer.

In the present invention, the two-layer type printed circuit board is a general term for a printed circuit board having no adhesive layer between the insulating film and the conductive metal layer.

In the two-layer type printed circuit board of the present invention, a conductive metal layer is provided on an insulating film having no adhesive layer. The adhesion between the film and the conductive metal layer is improved, and the insulating film is formed. For the purpose of preventing metal diffusion, improving etching characteristics, barrier of moisture, etc., first, a vapor deposition layer made of titanium, chromium, zirconium, nickel, tin, palladium, copper or their alloys, ceramics is provided, and It is preferable to provide a conductive metal layer. In the present invention, the conductive metal layer is preferably composed of a vapor deposition layer and a copper plating layer made of copper or a copper alloy having good conductivity. Further, a mode in which the conductive metal layer is the copper foil itself and the insulating film is a polyimide film is also preferable. In this case, a modified polyimide precursor varnish is applied on a copper foil and heat-treated to form a polyimide film layer, and a circuit pattern is formed by a known process.

The circuit pattern is formed by a known photosensitive resin-UV exposure-etching step or thermosetting resin-
It can be easily performed in the etching process.

When an electronic component such as an IC is mounted on a circuit board, nickel, palladium,
By forming the plating of gold, tin, solder, platinum and their compounds, the connection between the substrate and the electronic component such as the IC chip or the connecting line can be made more reliable.

The insulating film is not particularly limited, but polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyether ketone, aromatic polyamide, polyarylate, polyimide,
Films such as polyamideimide and polyetherimide can be used. Among them, polyethylene terephthalate film, polyphenylene sulfide film and polyimide film having stable dimensional stability and dielectric constant / dielectric loss tangent are preferably used. Among them, polyimide is most preferable because it has high heat resistance. In addition,
Prior to vapor deposition, these films are preferably subjected to a physical or chemical surface treatment such as corona discharge treatment or plasma discharge in order to improve surface cleaning and adhesion.

The vapor-deposited layer can be formed by a vacuum vapor-deposition method, sputtering or an ion-plating method. The sputtering method and the ion-plating method can form a film while cleaning with an ion bombardment to obtain a strong adhesion. Method is preferred.

In the present invention, a metal-containing substance layer is formed on the surface of an insulating film by a chemical treatment in an aqueous solution, and then a copper plating layer is formed thereon to form a layer made of a conductive metal. Embodiments are also possible. That is,
In the two-layer type printed circuit board, the surface of the insulating film is activated in an aqueous solution such as caustic soda until the entire surface is evenly wetted, and then a catalytic metal such as palladium and an adsorption layer for those compounds are formed. It is also possible to form electroless copper or electroless nickel, or electroless copper plating to a predetermined thickness to form a circuit pattern by a known process.

In the two-layer type printed circuit board of the present invention, the insulating film is adhered to a copper plate by using an adhesive made of the same kind of polymer as the insulating film, and the dielectric film between the insulating film and the adhesive is adhered. It is preferable to reduce the difference between the index and the dielectric loss tangent as much as possible. In this case, the adhesive layer needs to be as thin as possible.

According to the present invention, an IC of a wireless IC card
Mounting restrictions for electronic parts such as modules are remarkably alleviated, the functions and capacities of the modules can be upgraded, and high reliability of access to readers and riders can be obtained. Cash card, prepaid card
It is possible to have several kinds of functions such as credit card and credit card.

[0027]

EXAMPLES Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these. (Example 1) A 25-micron-thick polyimide film "Kapton V" (manufactured by Toray DuPont)
A dielectric constant of 3.5 and a dielectric loss tangent of 0.0016) were treated by corona discharge treatment up to 72 dynes or more at which water was sufficiently wet. The film was set in a sputtering device and evacuated to 5 × 10 ^{-5 torr} , then adjusted to 2 × 10 ^-3 torr with argon gas to make nickel to a thickness of 100 angstroms at a sputtering voltage of 500 V, A 2000 angstrom copper vapor-deposited film was formed on the nickel vapor-deposited film by the same method. 2 these steps
This was repeated to form a nickel / copper vapor deposition film on both sides. After deposition,
Immediately, 10 μm electroplating was performed with a current density of 3 A / dm ² in a high-concentration copper sulfate plating bath with a sulfuric acid concentration of 150 g / l. After electrolytic copper plating, a photosensitive dry film was laminated on both sides and exposed to ultraviolet rays using a mask. Then, copper and nickel were etched out with a ferric chloride solution to form a circuit pattern. The exposed parts of the circuit pattern other than the electronic parts mounting part and connection part are masked with a resist, and the exposed circuit pattern part is made of electroless nickel 5 μm, electroless gold.
1 micron was applied. As a result, the total thickness of the insulating film maintaining the initial electric characteristics is 57.4 μm and the wire bonding characteristics of the gold wire at 420 ° C. are excellent. A printed circuit board was obtained. (Example 2) 25 micron polyimide film "Kapton E" (manufactured by Toray DuPont: dielectric constant 3.4, dielectric loss tangent)
0.002) was dipped in 100 g / l caustic soda solution for 5 minutes at 60 ° C, and after confirming that the entire surface was uniformly wet, the treated film was dipped in 1 g / l stannous chloride solution. Then, after washing with water, it is dipped in a 0.2 g / l palladium chloride solution, and then 0.2 micron of nickel is formed by electroless plating. Then, the copper copper plating of Example 1 A printed circuit board for an IC card was obtained. (Comparative Example 1) A 25 micron polyimide film "Kapton V" was treated by corona discharge treatment to 72 dynes or more at which water was sufficiently wet. An epoxy adhesive was applied to each side of the treated film by 25 μm, and then a commercially available 18 μm copper foil was laminated and heat-cured. Then, patterning and nickel-gold plating were performed in the same steps as in Example 1 to obtain a printed circuit board for a three-layer type wireless IC card. However, the epoxy-based adhesive had a dielectric constant of 4.5 and a dielectric loss tangent of 0.03, which was different from the above "Kapton V". The total thickness was 121.4 microns, which was more than twice the thickness of Example 1.

[0028]

As described above, according to the present invention, the functions and capacities of electronic parts such as ICs of wireless IC cards can be upgraded and the readers and riders can be upgraded.
Highly reliable access to the contact IC card
It can be expected that it will be possible to move from a wireless IC card to a wireless IC card and make a major leap forward in terms of security and to expand the use of the card.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

[Explanation of symbols]

 1 ... Insulating film (polyimide film) 2 ... Sulfur 3 ... Nickel vapor deposition film / copper vapor deposition film 4 ... Electrolytic copper plating 5 ... Electroless nickel 6 ... Electroless gold 7 ... Printed circuit board for two-layer type wireless IC card

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H05K 1/03 610 G06K 19/00 K

Claims (9)

[Claims] 1. A printed circuit board on which an IC module is mounted is composed of a two-layer type printed circuit board in which a layer made of a conductive metal is provided on one side or both sides of an insulating film having no adhesive layer. A characteristic printed circuit board for wireless IC cards. 2. The polymer constituting the insulating film is polyethylene terephthalate, polyethylene naphthalate,
The wireless IC card print according to claim 1, wherein the polymer is a polymer selected from the group consisting of polyphenylene sulfide, polyether ketone, aromatic polyamide, polyarylate, polyimide, polyamidimide and polyetherimide. Circuit board. 3. The radio according to claim 1, wherein the layer made of a conductive metal is composed of a vapor deposition layer made of copper or a copper alloy and a copper plating layer which are sequentially formed when viewed from the side of the insulating film. Type IC card printed circuit board. 4. A two-layer type printed circuit board, wherein a vapor deposition layer made of metal and ceramics and a layer made of conductive metal are sequentially provided on an insulating film.
A printed circuit board for a wireless IC card according to claim 3. 5. The wireless IC card according to claim 1, which is a metal-containing substance layer formed by a chemical treatment in a layer aqueous solution of a conductive metal and a copper plating layer formed thereon. -Printed circuit board for power supplies. 6. The printed circuit board for a wireless IC card according to claim 1, wherein the insulating film is a polyimide film and the layer made of a conductive metal is made of a copper foil. 7. The wireless IC according to claim 1, wherein the two-layer printed circuit board is bonded to the copper plate using an adhesive made of the same polymer as the polymer of the insulating film.
Printed circuit board for card. 8. A layer formed of a conductive metal, which is formed by plating nickel, palladium, gold, tin, solder, platinum and a compound thereof.
A printed circuit board for a wireless IC card according to claim 7. 9. A wireless IC card produced by using the IC card printed circuit board according to claim 1.