JP2002043716A - Connecting structure, connecting method, ic card and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting structure, a connecting method, an IC card and its manufacturing method that can form a circuit of low resistance and that are excellent in reliability of connection. SOLUTION: A connecting structure is comprised of a circuit made of conductive paste and electronic parts. A connecting method is comprised of formation of the circuit by the conductive paste, overlap of the electronic parts, heating and pressurizing. An IC card is comprised of the circuit made of the conductive paste, the electronic parts and a cover film. A method for manufacturing the IC card is formation of the circuit made of the conductive paste, overlap of the electronic parts on it, overlap of a cover film on them, heating and pressurizing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a connection structure and a connection method, an IC card and a method of manufacturing the same.

[0002]

2. Description of the Related Art At present, cash cards, credit cards and the like which are widely used are provided with a magnetic stripe on a plastic card so that information recorded on the magnetic stripe can be read. Such a magnetic recording method has disadvantages that information can be easily read by a third party and the amount of recordable information is small.

[0003] In recent years, an IC card equipped with an IC chip having functions such as a memory and a CPU has been developed and is reaching a practical stage. In particular, interrogators (readers / writers) are used as non-contact IC cards that transmit and receive signals in a non-contact manner.
Transponder (non-contact IC card)
A device that generates an induced voltage in the antenna coil and uses it as a power source and performs data communication has attracted attention.

The basic circuit configuration of such a non-contact type IC card is such that an antenna coil pattern 2 and a circuit pattern 3 are formed on one surface of a plastic film 1 as shown in FIG. A face-down type IC chip 7 is directly connected via an anisotropic conductive adhesive 6 to a substrate on which a jumper pattern 5 for connecting the antenna coil pattern 2 and the circuit pattern 3 via the through hole 4 is formed. Japanese Patent Application Laid-Open No. H8-310172 proposes an IC card in which a plastic film 8 serving as an outer layer of the IC card is interposed via an inner layer material.

[0005]

SUMMARY OF THE INVENTION Such a conventional IC
The circuit of the card is formed by selectively etching and removing the copper foil attached to the substrate, or by selectively etching and removing the aluminum foil attached to the substrate, or by applying a conductive paste to the substrate. Although it was formed by printing in a shape, when inexpensive aluminum foil was used as the conductor of the circuit and electronic components were connected thereon via an anisotropic conductive adhesive, high temperature and high When placed in a humid environment, IC
The connection resistance between the chip and the circuit is increased, and in some cases, the communication performance is reduced.

The present invention provides a connection structure, a connection method, and an IC which can form a low-resistance circuit and have excellent connection reliability.
An object of the present invention is to provide a card and a method for manufacturing the card.

[0007]

The present invention has the following features. (1) A connection structure composed of a circuit made of a conductive paste and electronic components. (2) A connection method in which a circuit is formed with a conductive paste, electronic components are stacked, and heating and pressing are performed. (3) An IC card comprising a circuit made of a conductive paste, an electronic component, and a cover film. (4) A method of manufacturing an IC card in which a circuit is formed with a conductive paste, electronic components are stacked thereon, a cover film is further stacked, and heating and pressing are performed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The conductive paste of the present invention is obtained by mixing metal particles such as flake silver powder and copper powder in a binder obtained by mixing a solvent with a resin such as a polyester resin and a phenoxy resin resin and stirring the mixture. Naturally, these resins may be mixed with a curing agent, a curing accelerator, a binder, a viscosity modifier such as a filler for improving printability, and the like, if necessary. The thickness of the conductive paste is preferably 5 to 50 μm, and the adjustment is performed by adjusting the amounts of the various additives as described above, the mesh of the screen plate when printing, and the thickness of the emulsion in the mask portion. The printing can be performed by adjusting printing conditions such as the type, thickness and shape of the squeegee, the angle between the squeegee and the screen plate, the moving speed of the squeegee, and the height of the screen plate and the print target. If the thickness is less than 5 μm, formation by printing becomes difficult, and if it exceeds 50 μm,
It becomes too thick and the surface is not flat, making it difficult to form an adhesive thereon.

As the electronic parts, chip parts such as an IC chip, a chip type capacitor, and a chip type take can be used, and the shape of the terminal is an area of 100 μm square or more, and the height of the terminal is about 15 μm. It is preferably a terminal.

[0010] The connection structure of the present invention is a structure in which an electronic component is overlaid on the conductive paste. By doing so, the connection between the conductive paste and the electronic component is not hindered even in a high-temperature and high-humidity environment in a later step, and high connection reliability can be maintained.

In order to achieve such a structure, a circuit is formed by a conductive paste, and the electronic component is stacked on the conductive paste without heating the circuit by the conductive paste, and heated and pressed. Done by The conditions of the heating and pressurization differ depending on the types of binders used for the conductive paste and their thicknesses, and can be determined by performing experiments in advance for each of them. In general,
The heating temperature is preferably 100 to 200 ° C.
If the temperature is lower than 00 ° C., any binder is not cured, and it is difficult to maintain the connection reliability. If the temperature exceeds 200 ° C., the substrate may be deteriorated, which is not preferable. Further, the pressure condition is preferably in the range of 0.3 to 30 MPa per terminal, and if it is less than 0.3 MPa, the terminal of the electronic component may not be sufficiently connected to the conductive paste. Exceeding the strength exceeds the strength of the substrate or the aluminum foil, which is not preferred.

If an antenna circuit is included in the circuit using the aluminum conductor, an IC card can be obtained, and the IC card can be manufactured by the above method.
In addition, a through-hole is formed on the back surface of the antenna circuit made of an aluminum conductor, a circuit continuous with the through-hole is formed with a conductive paste, an adhesive is laminated on the conductive paste, and an electron is formed on the adhesive. Stack the parts and heat
An IC card can be manufactured even when pressure is applied.

[0013]

Example 1 As shown in FIG. 1, a 9 μm-thick polyethylene terephthalate film was used as a base material, an etching resist was formed in a portion to be a circuit on the surface of an aluminum foil, and a circuit including an antenna circuit was formed. A conductive paste 9 using an unsaturated polyester resin-based binder, using a printing method,
It was formed to have a thickness of 20 μm. A semiconductor chip 10 and a cover film 11 are further stacked on the conductive paste 9.
An IC card was produced by heating and pressing under Pa conditions. At this time, a semiconductor chip having a size of 1.9 × 2.8 mm and terminals provided diagonally was used, and the height of the terminals was 15 μm. This IC card is
00 sheets were produced.

Comparative Example An IC card was manufactured in the same manner as in Example 1, except that an anisotropic conductive adhesive was applied to an aluminum conductor without using a conductive paste.

The IC card manufactured as described above is
It was left for 500 hours in an environment at 5 ° C. and a relative humidity of 85%. As a result, although there was no abnormality in the communication performance in any of the examples, the communication performance was reduced in 7% of the comparative examples.

[0016]

As described above, according to the present invention, it is possible to provide a connection structure and a connection method, an IC card and a method of manufacturing the same, which can use an inexpensive circuit and have excellent connection reliability. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a top view and a sectional view showing a conventional example.

[Explanation of symbols]

 1. Plastic film 2. 2. antenna coil pattern Circuit pattern 4. Through hole 5. 5. Jumper pattern 6. Anisotropic conductive adhesive IC chip 8. Plastic film 9. Conductive paste 10. Electronic components 11. Cover film

Continued on the front page F-term (reference) 2C005 MA31 NA08 NA34 PA04 5B035 AA04 AA07 BB09 CA01 CA08 CA23 5E336 AA04 BB02 BB12 BB15 BC15 BC34 CC31 DD13 DD32 EE05 EE08 EE17 GG30 5E338 AA02 AA12 AA16 BB25 BB71 BB31 BB25

Claims (4)

[Claims] A connection structure comprising a circuit made of a conductive paste and an electronic component. 2. A connection method in which a circuit is formed with a conductive paste, electronic components are stacked, and heating and pressing are performed. 3. An IC card comprising a circuit made of a conductive paste, an electronic component, and a cover film. 4. A method of manufacturing an IC card in which a circuit is formed with a conductive paste, an electronic component is stacked thereon, a cover film is further stacked, and heating and pressing are performed.