JP2003109699A - Conductive terminal, its jointing method, and information communication medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jointing method for conductive terminals that can positively, stably and easily joint the conductive terminals to each other, resulting in acquiring much higher reliability than a conventional method and remarkably reducing the cost by the improvement of yield. SOLUTION: In the jointing method for conductive terminals of plane shape facing each other, an inclusion with properties that can apply reaction to the conductive terminals is arranged between the conductive terminals to obtain electrical connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for joining conductive terminals facing each other, and particularly to an IC card and an I card.
The present invention relates to a structure and method relating to joining of an antenna terminal of an IC module and a terminal terminal of a transmitting / receiving antenna coil in a card and sheet-shaped information communication medium represented by a C tag or the like.

[0002]

2. Description of the Related Art Conventionally, as one of the techniques of this type, for example, in a contact and non-contact IC card, a technique using an anisotropic conductive film, that is, a diameter of 5 μm to 50 μm is used. There is a method in which conductive fine particles are dispersed in a thermosetting film and the upper and lower ends of the fine particles are brought into contact with facing conductive terminals by heating under pressure to obtain electrical connection between both terminals.

However, in the above method, the particle size of the fine particles varies greatly, and only a small part of the fine particles dispersed in the film are in contact, and the fine particles themselves are small and the elasticity is extremely small. . Therefore, reliability problems such as frequent contact troubles due to repeated thermal expansion and contraction due to physical stress application or temperature change cannot be ignored.

Also, two of the prior arts are the same ICs.
In the card, a technique using a conductive paste, that is, applying an uncured conductive paste to one or both surfaces of the facing conductive terminals, and leaving it at room temperature under pressure or heating to cure it There was a way to get an electrical connection.

[0005]

However, in this method, although the precision of the amount of the conductive paste applied is strictly required, the paste viscosity varies greatly due to environmental conditions such as time, temperature and humidity. It is extremely difficult to guarantee the accuracy of the amount, and as a result, problems such as contact failure due to insufficient coating amount, conversely short circuit between other terminals due to excess paste due to excessive coating amount, or appearance defect due to leakage to the surface layer I was holding.

Therefore, the problem to be solved by the present invention is to ensure that the conductive terminals can be bonded reliably, stably, and easily, resulting in high reliability, and a significant reduction in cost due to improved yield. An object of the present invention is to provide a conductive terminal, a method for joining the conductive terminal, and an information communication medium that enable the same.

A further problem to be solved by the present invention is to provide a highly reliable and inexpensive information communication medium by using the improved joining method for the conductive terminals.

[0008]

According to the present invention, when joining conductive terminals facing each other, an elastic inclusion is sandwiched between the conductive terminals, and a force is applied so that the inclusion always pushes the conductive terminal. The electrical contact with good reliability is made by continuing.

That is, the present invention is a conductive terminal in which an interposition having a property capable of exerting a drag force is arranged therebetween to obtain an electrical connection. Further, in the present invention, in the method of joining flat conductive terminals facing each other, an electrical connection is obtained by disposing an interposition having a property capable of exerting a resistance force on the conductive terminals between the conductive terminals. This is a method of joining conductive terminals.

Further, the present invention is a method for joining conductive terminals, wherein any one of conductive particles, elastic springs, beads and shape memory alloy is used as the inclusion.

In the present invention, the conductive particles as inclusions have a diameter in the range of 50 μm to 500 μm, an elastic modulus of 2000 kg / mm ² or more, an elastic limit of 20% or more, and an elastic modulus of 10% to 90% or less. This is a method of joining conductive terminals, which are elastic bodies in the range.

The present invention is also a method for joining conductive terminals, wherein the conductive particles as the inclusions form a conductive film on the surface of polymer particles.

Further, according to the present invention, the conductive particles, which are the inclusions, are obtained by applying uncured conductive paste to the surface of polymer particles, and a method of bonding a conductive terminal in which the conductive particles are cured after mechanical bonding. Is.

Further, the present invention is an information communication medium using facing conductive terminals formed by the method for bonding conductive terminals according to any one of the above, wherein one conductive terminal of the facing conductive terminals is an IC. It is an information communication medium which has an antenna joining terminal pulled out from a chip and uses the other conductive terminal as a terminal terminal of a transmitting / receiving antenna coil.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A conductive terminal, a method for joining the conductive terminal, and an information communication medium according to an embodiment of the present invention will be described below. In particular, the content of the present invention is
The description will be focused on the case of application to the C card.

(Embodiment 1) A conductive terminal and a joining method thereof according to Embodiment 1 of the present invention will be described below. FIG. 1 is an explanatory diagram of a method of joining conductive terminals according to a first embodiment of the present invention. FIG. 1A is an explanatory diagram of an inclusion M that applies a resistance force F as indicated by an arrow to both conductive terminals between the conductive terminals 11 and 12 facing each other. Here, the point of the present invention in which the inclusion M is always capable of maintaining good contact with both conductive terminals is shown in a schematic sectional view.

Here, the conductive particles as the inclusions M have a diameter in the range of 50 μm or more to 500 μm or less, an elastic modulus of 2000 kg / mm ² or more, an elastic limit of 20% or more, and an elastic modulus of 10% or more to 90%. The elastic body has the following range.

FIGS. 1 (b) to 1 (d) are for explaining a concrete example of the inclusion M in FIG. 1 (a).
(B) is an example of an elastic sphere (the inside may be hollow). When the elastic sphere sandwiched between the conductive terminals 11 and 12 is compressed and fixed, it becomes a flat ellipsoid, and a dragging force as shown by an arrow in the drawing tends to be restored, which is consistent with the intention of the present invention.

Similarly, in FIG. 1C, a spring material is used.
It is intended to obtain the intended drag force of the present invention. Here, the spring material itself is generally a metal for the reason of its composition, but it does not mean that the electrical contact property is extremely excellent. Therefore, it is still preferable to form a thin metal layer having good conductivity such as gold on the surface by plating or the like. preferable.

FIG. 1 (d) shows a bead-shaped inclusion M, which is a metal material having elasticity, such as phosphor bronze or tungsten, or a polymer material such as polyethylene or nylon, with a part cut off as shown in FIG. It shows the applicability to the present invention. Here again, it is more effective if a thin electrically conductive layer is formed on the surface.

FIG. 1 (e) shows a drag generating means different from the above. For example, a U-shape having a certain curvature is stable in a temperature range of 100 ° C. or lower, and a U-shape having a smaller curvature is stable in a temperature range of 100 ° C. or higher. By using the shape memory alloy sheet as an interposer, the sheets having the electrode terminals are bonded and fixed with a small curvature during the thermocompression bonding process at a temperature of 100 ° C. or more, and the temperature of 100 ° C. after the process is completed. In the following, it is possible to obtain a drag force that matches the intention of the present invention by trying to return to a shape with a large curvature.

As described above, the point of the present invention is to maintain good electrical contact by continuously pushing the opposing conductive terminals by the drag force.

Next, as a more specific embodiment of the present invention, in the manufacture of an IC card, an embodiment in which the present invention is applied by using the elastic sphere shown in FIG. Detailed description.

(Embodiment 2) FIG. 2 is an explanatory diagram in the case where the method of joining conductive terminals according to Embodiment 2 is applied to an IC card. FIG. 2A shows a general means such as direct drawing of a metal film on the surface of an inlet sheet made of a card base material such as polyethylene terephthalate (hereinafter abbreviated as PET-G) or print patterning with a conductive ink. After forming the transmitting and receiving antenna coil 2, the same PET is used.
FIG. 3 is a schematic cross-sectional view showing a state in which the inlet sheet is sandwiched by upper and lower reinforcing sheets made of a −G material, and as a result, a structure in which the antenna coil 2 is embedded inside the PET-G base card 1 is realized.

FIG. 2B shows, after the state shown in FIG. 2A, the depth at which the joining terminal at the terminal end portion of the embedded antenna coil 2 is exposed from the upper surface side using, for example, a milling machine. Then, after the counterbore excavation processing is performed to a depth that the sealing resin portion made of epoxy resin or the like that covers the IC chip of the IC module in the subsequent step is fitted, the exposed antenna coil 2 is exposed. This is a state in which the conductive paste 4 is applied near the surface of the joining terminal portion and the conductive particles 5 are arranged before the conductive paste 4 is completely cured.

Here, as the conductive particles, for example, metal such as copper, brass, nickel and chromium is electrolessly or electrolytically plated on the surface of elastic particles such as gelatin, gum arabic, polyurea, nylon, polyurethane and polyethylene. A conductive layer is formed by such means as described above. Further, when the conductive particles are arranged at a predetermined position, the process can be performed without changing the position because the joint terminal portion of the antenna coil 2 is formed to be slightly recessed from the surroundings and the presence of the uncured conductive paste. Of.

FIG. 2C shows a state in which the IC module 6 is aligned and is just about to be fitted into the countersunk portion, and the conductive particles 5 are provided directly above the joint terminal portion of the antenna coil 2. Antenna terminal 7 on the IC module 6 side
Are arranged facing each other. Further, a thermosetting film 8 is attached to the peripheral area surrounding the conductive particles 5, and is responsible for the firm joining of the IC module 6 and the base card 1.

FIG. 2D shows a state in which the IC module 6 and the base card 1 are integrated by performing thermocompression bonding from above in the state of FIG. 2C to complete the basic structure of the IC card. At this time, the conductive particles 5 ′ are fixed while maintaining a flat cross-sectional shape due to the pressure contact stress from above and below, and the elasticity of the conductive particles 5 ′ always exerts a drag force on the IC module 6 and the IC module side antenna terminal 7.

As described above, in the IC card to which the present invention is applied, since the conductive particles having elastic ability are interposed between the facing bonding terminals, good electrical contact between the bonding terminals is always maintained. Therefore, the IC card can be made highly reliable.

[0030]

As described above, according to the present invention, the contact trouble between the conductive terminals, which has been a problem in the past, can be greatly improved under various use conditions and environmental conditions, and the reliability is high. In addition, it is possible to provide an inexpensive conductive terminal, a method of joining the conductive terminal, and an information communication medium, which are inexpensive due to the improvement in yield.

In the above-mentioned embodiment, only the example of the IC card has been described, but the present invention is not limited to this, and IC tags, optical, magnetic and dielectric materials, and composite card-like forms and sheets of these. It goes without saying that the electrode joining technique of the present invention can be applied to all information communication media such as a label and a label.

Further, the electrode joining technique of the present invention is not limited to the information communication medium, and is applied to any situation where reliable joining of a plurality of electrode terminals facing each other is required. It is possible to do so.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a method of joining conductive terminals according to a first embodiment of the present invention. FIG. 1A is an explanatory view of inclusions, and FIG.
1 (b) is an explanatory view of an elastic sphere, FIG. 1 (c) is an explanatory view using a spring material, FIG. 1 (d) is an explanatory view of a bead-shaped inclusion with a part cut off, and FIG. e) is an explanatory view using a shape memory alloy sheet as an inclusion.

FIG. 2 is an explanatory diagram when a method of joining conductive terminals according to a second embodiment of the present invention is applied to an IC card. Figure 2 (a)
2 is a view showing a state in which a transmitting / receiving antenna coil is formed on the surface of an inlet sheet made of a card base material, FIG.
2B shows the depth after the state shown in FIG. 2A that the bonding terminal at the terminal end of the embedded antenna coil is exposed, and the epoxy that seals and covers the IC chip of the IC module in a later step. After carrying out counterbore excavation processing to a depth at which a sealing resin portion made of resin or the like is fitted, a conductive paste is applied near the exposed surface of the bonding terminal portion of the antenna coil 2 to dispose conductive particles. Fig. 2 (c)
Is a diagram showing a state immediately before the IC module is aligned and fitted into the base card. FIG. 2 (d) is a state shown in FIG. 2 (c). The figure which shows the state which integrated the basic structure of an IC card by integrating and.

[Explanation of symbols]

1 Base card (PET-G; inlet sheet,
Upper and lower layer reinforcing sheets) 2 Antenna coil (or its terminal joining terminal portion) 3 Countersunk holes excavated in the base card 4 Conductive paste 5 Conductive particles (before pressure bonding) 5'Conductive particles (after pressure bonding) 6 IC module (IC chip, module) Wiring board, sealing resin) 7 IC module side antenna terminal 8 Thermosetting film 11 Conductive terminal 12 arranged above The conductive terminal M arranged below The inclusion F arranged between the conductive terminals has a shape Drag that occurs when trying to restore

Claims (7)

[Claims] 1. A conductive terminal, characterized in that an interposition having a property capable of exerting a drag force is disposed therebetween to obtain an electrical connection. 2. A method for joining flat conductive terminals facing each other, wherein an electrical connection is obtained by disposing an interposition having a property capable of exerting a drag force on the conductive terminals between the conductive terminals. And a method for joining conductive terminals. 3. The method for joining conductive terminals according to claim 2, wherein any one of conductive particles, elastic springs, beads, and shape memory alloy is used as the inclusions. 4. The conductive particles, which are the inclusions, have a diameter of 50.
Range of μm to 500 μm, elastic modulus 2000
kg / mm ² or more, elastic limit of 20% or more, elastic modulus of 10%
From the above, it is an elastic body in the range of 90% or less, The method for joining conductive terminals according to claim 2 or 3, wherein. 5. The conductive terminal bonding according to claim 2, wherein the conductive particles as the inclusions are formed by forming a conductive film on the surface of the polymer particles. Method. 6. The conductive particles as the inclusions are obtained by applying uncured conductive paste on the surface of polymer particles, and are cured after mechanical bonding. The method for joining conductive terminals according to Item 3. 7. The information communication medium using the conductive terminal according to claim 1, wherein one conductive terminal of the facing conductive terminals is an antenna joining terminal pulled out from an IC chip, and the other conductive terminal is a transmitter / receiver. An information communication medium, which is used as a terminal terminal of an antenna coil for use.