JPH08252995A - Manufacture of ic card - Google Patents

Abstract

PURPOSE: To thin a thickness of an IC card which uses a microstrip antenna by arranging an IC chip at an opening of a spacer and connecting a pump of the IC chip and a circuit pattern electrically. CONSTITUTION: An IC card 100 comprises a substrate 1 having a circuit pattern 2 and an antenna pattern 3 as a receiving function formed on its top face 1a, an opening 12, and a through hole 6. On a top face 4a, an insulating spacer 4 having an earth pattern 5, an opening 12 which is the same as the spacer 4, and the through hole 6 are arranged. The top face 1a of the substrate 1 and a bottom face 4b of the spacer 4 are joined by an adhesive sheet 11. A pump 8 of an IC chip 7 is attached with pressure to the circuit pattern 2 through an anisotropic conductive adhesive 9 so as to electrically connect the pump 8 and the circuit pattern 2. Also, the antenna pattern 3 and the earth pattern 5 are connected electrically by the through hole 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card having an IC chip and a transmission / reception function and used for pallet management, entry / exit management, vehicle management, commuter pass, ski lift ticket, airline baggage tag, etc. .

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
Substrate 21 having 2 and having a circuit pattern 22 formed on its upper surface
And a prepreg 30 as a semi-cured insulating substrate having an opening 32 similar to that of the substrate 21 under the substrate 21, and a copper foil as the ground pattern 25 under the prepreg 30 are sequentially stacked, After laminated by pressing, the adhesive 29 is applied to the lower surface of the insulating spacer 24 having the opening 33 larger than the opening 32, and the spacer 2 is formed.
4 is laminated and fixed on the upper surface of the substrate 21 by hot pressing, the IC chip 27 is inserted through the openings 32 and 33, and the IC
The bottom surface of the chip 27 and the ground pattern 25 are connected by the solder paste 31, and the terminals formed on the upper surface of the IC chip 27 and the circuit pattern 22 are electrically connected by wire bonding via the wire 26, and the opening is formed. Parts 32, 3
There is known an IC card 200 configured by filling a molding agent 20 into a gap between the IC chip 27 and the IC chip 27 (Japanese Patent Laid-Open No. 6-1096). This is a structure in which a circuit pattern 22 (including an antenna pattern) and a ground pattern 25 are formed with a substrate 21 (including a prepreg 30) interposed therebetween,
In the case of the IC card 200 having this structure, the ground pattern 25
Circuit pattern 2 because it blocks the reflection of radio waves.
Radio waves are emitted from 2.

However, in the configuration shown in FIG. 3, I
In order to electrically connect the terminals of the C chip 27 and the circuit pattern 22 by wire bonding, the IC card 200
However, there is a problem in that the thickness cannot be reduced and the thickness cannot be reduced.
As means for solving this problem, JP-A-2-21219
There is known a mounting method in which an IC chip and a circuit pattern are electrically connected via bumps as shown in Japanese Patent Laid-Open No. However, the IC card described in this publication adopts a single-sided board dipole antenna as the antenna. The features of this dipole antenna are
Since there is no surface such as a ground pattern that blocks radio waves, an electric field is generated on both antenna surfaces (both sides of the IC card), enabling transmission / reception in almost all directions. This seems good at first glance, but being able to transmit in all directions means being influenced by the outside world in all directions.
The microwave communication adopted in this type of IC card is greatly affected by moisture, that is, the body. In other words, when a person holds this card, when they pick up the edge of the card to communicate, they are hardly affected by the hand, but when they hold the card so as to cover it with the back of their hand, they are affected by the hand and the communication distance is extremely long. There is a problem that it drops to.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, in an IC card that employs a microstrip antenna (also called a patch antenna) that is not easily affected by the external environment, the above-mentioned bumps are used to reduce the thickness and weight. Then, it was considered to adopt a mounting method for connecting the IC chip and the circuit pattern. However, for that purpose, how to make a double-sided board sandwiched between a ground pattern and a circuit pattern (including an antenna pattern) becomes a problem, and how to make a through hole connecting the ground pattern and the circuit pattern. That is also a problem. That is, an object of the present invention is to produce a double-sided board with through holes suitable for a mounting method in which an IC chip and a circuit pattern are connected via bumps, thereby reducing the thickness of an IC card using a microstrip antenna. It is to be.

[0005]

In order to solve the above-mentioned problems, the means described in claim 1 can be adopted. According to this means, first, a ground pattern is formed on one surface of the spacer, and a through hole is formed between the opening on which the IC chip can be arranged and the surfaces on both sides of the opening. Next, a circuit pattern including an antenna pattern is formed on one surface of the insulating substrate. Then, the surface of the insulating substrate on which the circuit pattern is formed and the surface of the spacer on which the ground pattern is not formed are bonded. At this time, the through holes are positioned on the circuit pattern. After that, a conductive paste is filled in the through hole of the spacer to electrically connect the ground pattern and the circuit pattern. Then, the IC chip is arranged in the opening of the spacer, and the bumps of the IC chip and the circuit pattern are electrically connected. This enables the IC card to be thin and lightweight. Here, a conventional method for manufacturing the IC card 300 with through holes is shown in FIG. In this manufacturing method, first, the copper foil 41 is formed on both surfaces of the base material 40.
Are formed (FIG. 9A). Next, the lower surface 40b of the base material 40
The copper foil 41 formed on the side is subjected to pattern etching to form a circuit pattern 42 (FIG. 9B). The copper foil 41 on the upper surface 40a side of the base material 40 is left as it is to form the ground pattern 43. Subsequently, the base material 40 and the ground pattern 4
3 and the circuit pattern 42 are penetrated to form a through hole 44 (FIG. 9C). Then, the conductive material 4 is placed in the through hole 44.
7 is formed by plating to form a through hole 45,
The circuit pattern 42 and the ground pattern 43 are electrically connected through the through hole 45 (FIG. 9D). Then, the IC chip 46 is electrically connected to the circuit pattern 42 (FIG. 9E). In this way, the IC card 300
However, since the circuit pattern 42 is formed on the outer surface on the lower side in the drawing, the IC chip 46 is mounted on the outside of the substrate, and the overall thickness increases. However, according to the means described in claim 1, since the insulating substrate and the spacer are adhered in a state where the circuit pattern provided on the insulating substrate is directed upward, the spacer is provided through the opening of the spacer. The IC chip can be mounted on the circuit pattern facing upward, and the total thickness does not exceed the state before mounting the IC chip. Furthermore, when the conductive paste is filled in the through hole, one end of the through hole is blocked,
Since the conductive paste is filled in such a manner as to be poured, the conductive paste is sufficiently filled to the inside of the through hole, and the electrical connection between the circuit pattern and the ground pattern is surely performed.

According to the second aspect of the present invention, first, the opening where the IC chip can be arranged is formed in the spacer, and the through hole is formed between the surfaces on both sides of the spacer. A circuit pattern is formed on the surface. Next, the surface of the insulating substrate on which the circuit pattern is formed is adhered to the spacer. At this time, the through holes are positioned on the circuit pattern. Subsequently, the through-hole is filled with a conductive paste, a ground pattern is formed on the surface of the spacer on the non-bonded side of the insulating substrate, and an electrical connection with the circuit pattern is formed through the conductive paste in the through-hole. Make a connection. Then, an IC chip is placed in the opening of the spacer, and the bump and the circuit pattern are electrically connected. As a result, the same effect as that of the first aspect can be obtained.

According to the third aspect of the present invention, first, after forming the opening in which the IC chip can be arranged in the spacer and the through hole between the surfaces on both sides of the spacer, one of the insulating substrates is formed. A circuit pattern is formed on the surface. Next, the surface of the insulating substrate on which the circuit pattern is formed is adhered to the spacer. At this time, the through holes are positioned on the circuit pattern. Subsequently, a grounding pattern is formed using a fluid conductive paste on the surface of the spacer that is not bonded to the insulating substrate, and at the same time, the conductive paste is poured into the through holes to form the circuit pattern and the ground pattern. Connect electrically. And place an IC chip in the opening of the spacer,
The bump and the circuit pattern are electrically connected. As a result, the same effect as that of the first aspect can be obtained.

By adopting the means described in claim 4, it is possible to more easily manufacture the IC card without requiring the labor as in the conventional electrical connection by wire bonding.

By adopting the means described in claim 5, since it becomes easy to fill the conductive paste in the through hole, the connection pattern and the conductive paste in the through hole are smoothly connected, and cutting in the middle Since it is less likely to occur, the circuit pattern and the ground pattern can be more reliably electrically connected via the conductive paste in the through hole.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on specific embodiments. FIG. 1 is a schematic diagram showing the configuration of the cross section of the first embodiment of the present invention. The IC card 100 includes a substrate 1 (corresponding to an insulating substrate) having a circuit pattern 2 and an antenna pattern 3 as a receiving function formed on an upper surface 1a (corresponding to one surface of an insulating substrate), an opening 12 and a through. The substrate 6 is provided with a hole 6, an insulating spacer 4 having a ground pattern 5 formed on an upper surface 4a (corresponding to one surface of the spacer), an opening 12 similar to the spacer 4, and a through hole 6. A sheet adhesive film 11 for adhering the upper surface 1a of the substrate 4 to the lower surface 4b of the spacer 4, an IC chip 7 arranged in the opening 12 of the spacer 4, having a bump 8 as a terminal, and electrically connected to the circuit pattern 2,
From the anisotropic conductive adhesive 9 for electrically connecting and bonding the bumps 8 of the IC chip 7 to the circuit pattern 2, and the epoxy type molding agent 10 filling the gap between the opening 12 of the spacer 4 and the IC chip 7. Composed.

The substrate 1 is made of PET (polyethylene terephthalate) having a thickness of 25 μm, and the circuit pattern 2 and the antenna pattern 3 are made of silver paste. The spacer 4 is made of PET having a thickness of 500 μm, and the ground pattern 5 is made of silver paste. Through hole 6
Is a conductive paste 6b made of a silver paste.
Are formed by electrically connecting the antenna pattern 3 and the ground pattern 5 to each other.

The anisotropic conductive adhesive 9 is an adhesive which is formed by mixing nickel (Ni) particles in a non-conductive adhesive to make an electrical connection only in the pressure bonding direction. The action is
When crimped, the nickel particles in the crimping direction make electrical contact only in the crimping direction, the nickel particles do not make contact in any direction other than the crimping direction, and the electrical connection is not made in any direction other than the crimping direction. It is a thing. The sheet adhesive film 11 is an insulative adhesive, and is a hot-melt adhesive that melts when reaching a predetermined temperature range and solidifies when the temperature returns to room temperature for adhesion.

As shown above, the bumps 8 of the IC chip 7 are pressure-bonded to the circuit pattern 2 via the anisotropic conductive adhesive 9, and the bumps 8 and the circuit pattern 2 are electrically connected only in the pressure-bonding direction. Further, the IC chip 7 can be accommodated within the thickness range of the spacer 4 by the configuration in which the antenna pattern 3 and the ground pattern 5 are electrically connected by the through hole 6 provided in the spacer 4. Therefore, the IC card 100 can be made thinner and lighter.

Next, an embodiment of the method of manufacturing the IC card 100 will be described. FIG. 2 shows a sectional structure in the order of manufacturing steps of this embodiment. First, as shown in FIG. 2A, the ground pattern 5 is formed on the upper surface 4a of the spacer 4, and the ground pattern 5 and the circuit pattern 2 are penetrated through the ground pattern 5 and the spacer 4 (FIG. 2B). Hole portion 6a (corresponding to a through hole) for the through hole 6 for electrically connecting with the IC chip 7 (see FIG. 2E) and an opening portion having a size as large as possible. 12 and 12 are formed. Next, as shown in FIG. 2B, components are stacked under the spacer 4. That is, the sheet adhesive film 11 in which the openings 12 and the holes 6a similar to those of the spacer 4 are formed is provided under the spacer 4, and the circuit pattern 2 and the antenna pattern 3 have the upper surface 1 under the sheet adhesive film 11.
Substrates 1 formed on a are sequentially stacked. At this time,
It is not necessary to form openings or holes in the substrate 1.

After stacking the spacer 4, the sheet adhesive film 11 and the substrate 1 in order, hot pressing is performed, and the sheet 1 and the spacer 4 are melted by melting the sheet adhesive film 11.
And is bonded (FIG. 2 (c)). Subsequently, the through hole 6 a is filled with the conductive paste 6 b to form the through hole 6, and the antenna pattern 3 is formed through the through hole 6.
And the ground pattern 5 are electrically connected (see FIG. 2).
(D)). After that, the anisotropic conductive adhesive 9 is applied on the circuit pattern 2, and the IC chip 7 is inserted from the opening 12.
The bumps 8 of the IC chip 7 are pressure-bonded onto the circuit pattern 2 via the anisotropic conductive adhesive 9, whereby the bumps 8 and the circuit pattern 2 are electrically connected in the pressure-bonding direction. The circuit pattern 2 is formed on the IC chip 7 by using the anisotropic conductive adhesive 9.
After being fixed on the top, the gap between the opening 12 and the IC chip 7 is filled with the molding agent 10 to complete the IC card 100 (FIG. 2E).

According to the above-mentioned embodiment, the IC chip 7 is pressure-bonded to the circuit pattern 2 using the bumps 8 and the anisotropic conductive adhesive 9 to electrically connect the IC chip 7 and the circuit pattern 2 in the pressure-bonding direction. By doing so, the IC card 100 can be manufactured in a shorter time, and the IC chip 7 can be accommodated within the range of the wall thickness t of the spacer 4 (FIG. 2E). The 100 can be made thin.

In the above embodiment, the thickness of PET constituting the substrate 1 and the spacer 4 is 25 μm and 500 μm, but the thickness is not limited to this and may be any thickness as required. Further, PET was used in the present embodiment as a material for forming the substrate 1 and the spacer 4, but the material is not limited to this, and PPS (polyphenylene sulfide), a composite sheet of PET and PPS, a polyimide film, and a glass epoxy are used. Any material generally used for a substrate material such as a film or a BT resin material may be used.

As a material for forming the circuit pattern 2 and the antenna pattern 3, a silver paste is used in this embodiment, but a conductive paste such as a copper paste or a silver / carbon paste, or an etching pattern of a copper foil may be used. Further, although the molding agent 10 is an epoxy type, it may be a UV curing type. The ground pattern 5 is formed of silver paste, but a metal foil such as an aluminum foil may be attached.

(Second Embodiment) Next, a second manufacturing method of the IC card 100 will be described. 4 shows the IC card 10
It is explanatory drawing which showed the 2nd manufacturing method of 0 typically. The feature of this embodiment is that the order of forming the ground pattern 5 is different from that of the manufacturing process described with reference to FIG.
And the spacer 4 are adhered to each other, the conductive paste 6b is filled in the hole 6a to form the through hole 6, and then the ground pattern 5 is formed. As shown in FIG. 4, first, the holes 6a and the openings 12 are formed in the spacer 4 (FIG. 4A). Next, the sheet adhesive film 11 having the holes 6a and the openings 12 similar to the spacer 4 and the upper surface 1
The substrate 1 having the circuit pattern 2 and the antenna pattern 3 formed on a is placed under the spacer 4 for positioning (FIG. 4B). Subsequently, the sheet adhesive film 11 is melted by hot pressing to bond the substrate 1 and the spacer 4 (FIG. 4 (c)). After this, a conductive paste 6b is filled in the hole 6a to form a through hole 6 for electrical connection with the antenna pattern 3 (FIG. 4 (d)), and silver paste is further formed on the upper surface 4a of the spacer 4. To form the ground pattern 5 by screen printing, and electrically connect the ground pattern 5 and the antenna pattern 3 through the through hole 6 (FIG. 4E). Then, the IC chip 7 is arranged in the opening 12, and the IC chip 7 is pressure-bonded onto the circuit pattern 2 through the anisotropic conductive adhesive 9 to electrically connect the bump 8 and the circuit pattern 2, The gap between the opening 12 and the IC chip 7 is filled with the molding agent 10 (see FIG. 4).
(F)). As described above, the ground pattern 5 may be formed after the through hole 6 is formed, and it is not necessary to form the ground pattern 5 on the spacer 4 from the beginning as in the embodiment shown in FIG.

(Third Embodiment) A third method of manufacturing the IC card 100 will be described. Figure 5 shows IC card 1
It is explanatory drawing which showed typically the 3rd manufacturing method of 00.
The feature of the present embodiment is that the process of filling the hole 6a with the conductive paste 6b and the process of forming the ground pattern 5 are performed simultaneously. As shown in FIGS. 5A to 5C, the spacer 4 having the hole 6 a and the opening 12 is formed.
Up to the step of bonding the substrate 1 on which the circuit pattern 2 and the antenna pattern 3 are formed with the sheet adhesive film 11 by hot pressing is the same as the second manufacturing method. Then, as shown in FIG. 5D, the hole 6a is formed.
When the ground pattern 5 is printed on the upper surface 4a of the spacer 4 provided with the liquid silver paste, the printing is also performed on the hole 6a. At this time, the silver paste flows downward along the inner wall surface of the hole 6a due to its fluidity and is formed in the hole 6a as the conductive paste 6c. Then, the conductive paste 6c is electrically connected by contacting the antenna pattern 3, and the ground pattern 5 and the antenna pattern 3 are electrically connected to complete the through hole 6.

As described above, by only printing the ground pattern 5 on the upper surface 4a of the spacer 4 with the fluid conductive paste 6c, the holes 6 are naturally formed due to the nature of the conductive paste 6c.
Since the conductive paste 6c flows into the inside of a and is electrically connected to the antenna pattern 3, the manufacturing process is shortened. Further, since the ground pattern 5 and the wiring in the through hole 6 both have the same property, there is little risk of breakage due to peeling or the like. The conductive pastes 6b and 6c are silver particles dispersed in a printing paint, and are dried by heating after printing to form a conductive print pattern. The fluidity of the conductive pastes 6b and 6c is adjusted by the blending ratio of the above components of the conductive pastes 6b and 6c.

Next, as a method of filling the hole 6a with the conductive paste 6b, there is a method shown in FIG. As shown in FIG. 6, the nozzle 13 is inserted into the hole 6a, and the conductive paste 6b is discharged from the nozzle 13 so that the conductive paste 6b is applied to the antenna pattern 3 deep inside the hole 6a. The conductive paste 6b is filled so as to be in contact with each other. As a result, even if the hole 6a is blocked on one side of the substrate 1, the nozzle 13
Is inserted and the conductive paste 6b is brought into contact with the antenna pattern 3 at the back (FIG. 6A), so that the ground pattern 5 and the antenna pattern 3 are electrically connected. In addition, the conductive paste 6b injected by the nozzle 13
If the amount of is equal to the volume of the through hole 6, the contact between the conductive paste 6b and the ground pattern 5 becomes more reliable (FIG. 6 (b)).

Next, the hole 6a and the opening 1 shown in FIG. 2 (a).
After forming 2, the hole 6a may be provided with a tapered portion 6d as shown in FIG. With this configuration, the conductive paste 6b for forming the ground pattern 5 easily enters the hole 6a, and the conductive paste 6b injected by the nozzle inside the hole 6a surely enters the antenna pattern 3. (See FIG. 7A).
Further, in the case where the formation of the fluid conductive paste 6c in the hole 6a and the formation of the ground pattern 5 are performed at the same time as in the manufacturing process shown in FIG. 5, the amount of the conductive paste 6c flowing is small. Since the number increases, the contact between the conductive paste 6c in the hole 6a and the antenna pattern 3 becomes more reliable, and this configuration is particularly effective (see FIG. 7B).

In the manufacturing process described with reference to FIG. 2, the molding agent 1 is placed in the gap between the opening 12 and the IC chip 7.
It was completed when 0 was filled (FIG. 8 (a)), but as shown in FIG. 8, labels 14 and 15 were attached to the outer surface of the substrate 1 and the surface of the ground pattern 5 with an adhesive or the like, respectively. (See FIG. 8B). In this case, label 1
4 and 15 are made of a material such as vinyl chloride (PVC) or polyethylene terephthalate (PET), and have a thickness of 1
Those having a diameter of 00 μm or less, preferably 25 to 50 μm are used.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the configuration of a first embodiment according to the present invention.

FIG. 2 is a schematic explanatory view showing a first manufacturing method according to the present invention.

FIG. 3 is a schematic cross-sectional view showing the configuration of a conventional IC card.

FIG. 4 is a schematic explanatory view showing a second manufacturing method according to the present invention.

FIG. 5 is a schematic explanatory view showing a third manufacturing method according to the present invention.

FIG. 6 is an explanatory view schematically showing a method of filling the inside of the hole with a conductive paste.

FIG. 7 is a schematic cross-sectional view showing the structure of a through hole 6 having a tapered portion at the upper end.

FIG. 8 is a cross-sectional view schematically showing the configuration of an IC card having a label attached to the outer surface.

FIG. 9 is a schematic view showing a conventional method for manufacturing a double-sided board with through holes.

[Explanation of symbols]

 1 substrate (insulating substrate) 2 circuit pattern 3 antenna pattern 4 spacer 5 ground pattern 6 through hole 7 IC chip 8 bump 9 anisotropic conductive adhesive 10 molding agent (filler) 11 sheet adhesive film (insulating adhesive) 12 opening 100 IC card

Claims (5)

[Claims] 1. A method of manufacturing an IC card in which an antenna pattern as a microstrip antenna and a ground pattern are formed so as to sandwich a spacer, and an IC chip electrically connected to the antenna pattern and the ground pattern is incorporated. And a step of forming the ground pattern on one surface of the spacer, an opening in which the IC chip can be arranged in the spacer, and a through hole formed between both surfaces of the spacer. And a step of forming a circuit pattern including the antenna pattern on one surface of an insulating substrate, and forming the circuit pattern of the insulating substrate so that the through hole is located on the circuit pattern. The bonded surface and the surface of the spacer on which the ground pattern is not formed, and A step of filling a conductive paste in the through hole to electrically connect the ground pattern and the circuit pattern, and disposing the IC chip in the opening of the spacer, and forming a bump of the IC chip. And a step of electrically connecting the terminal and the circuit pattern formed on the insulating substrate. 2. A method of manufacturing an IC card in which an antenna pattern as a microstrip antenna and a ground pattern are formed so as to sandwich a spacer, and an IC chip electrically connected to the antenna pattern and the ground pattern is incorporated. And a step of forming a through hole between the both sides of the spacer and an opening in which the IC chip can be arranged in the spacer, and the antenna pattern on one surface of the insulating substrate. A step of forming a circuit pattern including; a step of adhering the spacer to the surface on which the circuit pattern of the insulating substrate is formed, such that the through hole is located on the circuit pattern; Filling the through hole with a conductive paste, and on the surface of the spacer that is not bonded to the insulating substrate Forming the ground pattern so as to be electrically connected to the circuit pattern through the conductive paste; arranging the IC chip in the opening of the spacer, and using a bump of the IC chip. A method of manufacturing an IC card, comprising the step of electrically connecting the configured terminal and the circuit pattern formed on the insulating substrate. 3. A method of manufacturing an IC card in which an antenna pattern as a microstrip antenna and a ground pattern are formed so as to sandwich a spacer, and an IC chip electrically connected to the antenna pattern and the ground pattern is incorporated. And a step of forming a through hole between the both sides of the spacer and an opening in which the IC chip can be arranged in the spacer, and the antenna pattern on one surface of the insulating substrate. A step of forming a circuit pattern including; a step of adhering the spacer to the surface on which the circuit pattern of the insulating substrate is formed, such that the through hole is located on the circuit pattern; Simultaneously with forming the ground pattern using a fluid conductive paste on the surface not bonded to the insulating substrate. A step of simultaneously arranging the conductive paste in the through hole so as to electrically connect the circuit pattern and the ground pattern, and arranging the IC chip in the opening of the spacer, A method of manufacturing an IC card, comprising: a step of electrically connecting a terminal formed of a bump of a chip and the circuit pattern formed on the insulating substrate. 4. The adhesive for electrically connecting the bumps of the IC chip to the circuit pattern formed on the insulating substrate is an anisotropic conductive adhesive. The method for manufacturing an IC card according to any one of claims 1 to 3. 5. The step of forming the through hole between both side surfaces of the spacer comprises forming a taper portion at an end portion of the through hole on the ground pattern side. The method for manufacturing an IC card according to claim 3.