JP2011065473A - Portable electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable electronic device capable of controlling the breakage of an IC chip. <P>SOLUTION: The portable electronic device includes: a substrate 11; the IC chip 16 that is arranged opposite to the substrate 11; a first adhesive 18 that is interposed between the substrate 11 and the IC chip 16, and connects the substrate 11 with the IC chip 16; a reinforcing plate 20 arranged on the opposite side of the substrate 11 across the IC chip 16; and the second adhesive 19 that is interposed between the IC chip 16 and the reinforcing plate 20, possesses elastic modulus lower than that of the first adhesive 18, and connects the IC chip 16 with the reinforcing plate 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to portable electronic devices.

  In general, as an IC card, a contact IC card having a contact communication function, a non-contact IC card (wireless IC card) having a non-contact communication (wireless communication) function, and both contact communication and non-contact communication functions There is known a dual interface IC card having The dual interface IC card is classified into a combination IC card that processes contact communication and non-contact communication with one IC, and a hybrid IC card that processes contact communication and non-contact communication with individual ICs.

  For example, a non-contact type IC card has a card-type inlet. The inlet has a substrate, an electrode pattern formed on the substrate, and an IC chip. An IC card provided with an inlet can perform non-contact communication with an external communication device.

  The IC chip is mounted on the substrate using a flip chip mounting technique. The flip-chip mounting technique is a technique in which the protruding electrodes and the electrode patterns are electrically connected with the protruding electrodes (bumps) provided on the IC chip opposed to the electrode patterns formed on the substrate.

  As a connection method using the flip chip mounting technique, for example, a thermocompression bonding method is known. In the thermocompression bonding method, the protruding electrode of the IC chip and the electrode pattern on the substrate are bonded together through a conductive adhesive, and then heat and load are applied from above the IC chip to cure the adhesive. As a result, the substrate and the electrode pattern are bonded to the IC chip, and the electrode pattern and the protruding electrode are electrically connected to form a circuit. That is, physical bonding and electrical connection are simultaneously performed by one press bonding.

  The inlet further includes a reinforcing plate joined to the IC chip via an adhesive. The reinforcing plate reinforces the mechanical strength of the inlet. In the case where the reinforcing plate is used, cracks and cracks generated in the IC chip due to stress are suppressed as compared with the case where the reinforcing plate is not used. Each of the adhesive interposed between the substrate and the IC chip and the adhesive interposed between the IC chip and the reinforcing plate has a high elastic modulus.

  On the other hand, an IC card having a card substrate having a storage recess and an IC module stored in the storage recess is known (for example, see Patent Document 1). Since the adhesive for joining the IC module to the card substrate has a low elastic modulus and the adhesive can absorb stress, cracks and cracks occurring in the IC module (IC chip) can be suppressed.

Japanese Patent No. 3529420

  By the way, the IC module can be suppressed from being cracked or cracked by being stored in the recess for storage and bonded to the card base material with an adhesive. However, the case where the IC module is transported alone is considered. And there is a problem that the occurrence of cracks and cracks cannot be suppressed.

  Moreover, although the said inlet as an IC module is the structure which aims at suppression of generation | occurrence | production of a crack and a crack by itself, the elasticity modulus of each said adhesive agent is high. For this reason, when stress is applied to the reinforcing plate, since the stress is transmitted in the order of the adhesive and the IC chip with almost no absorption, the IC chip may be cracked or cracked.

  Therefore, in order to absorb the stress applied to the reinforcing plate with the adhesive and suppress cracks and cracks generated in the IC chip, it is conceivable to use the adhesives having low elasticity. However, in this case, there is a possibility that bulk destruction occurs, the protruding electrode is detached from the electrode pattern, and the function as an IC card (such as a wireless communication function) is lost.

In the future, since there is a tendency to further reduce the size and thickness of the IC chip, it is considered that the IC chip is further cracked or broken. For this reason, an IC module, an IC card, and the like that can suppress damage to the IC chip are required.
The present invention has been made in view of the above points, and an object thereof is to provide a portable electronic device capable of suppressing breakage of an IC chip.

In order to solve the above-described problem, a portable electronic device according to an aspect of the present invention is provided.
A substrate,
An IC chip disposed opposite to the substrate;
A first adhesive interposed between the substrate and the IC chip and joining the substrate and the IC chip;
A reinforcing plate disposed on the opposite side of the substrate to the IC chip;
And a second adhesive which is interposed between the IC chip and the reinforcing plate and has a lower elastic modulus than the first adhesive and joins the IC chip and the reinforcing plate.

  According to the present invention, it is possible to provide a portable electronic device that can suppress breakage of an IC chip.

1 is an exploded perspective view showing an IC card according to an embodiment of the present invention. It is sectional drawing which shows a part of said IC card. It is the top view which looked at the said IC card from the back side. FIG. 4 is a cross-sectional view showing a state where the IC chip shown in FIGS. 1 to 3 is thermocompression-bonded to a substrate by a pressurization / heat treatment unit in the IC card manufacturing process. FIG. 5 is a plan view showing a state where an IC chip is thermocompression bonded to a substrate in the manufacturing process of the IC card shown in FIG. 4. FIG. 5 is a cross-sectional view showing a state in which a reinforcing plate is thermocompression bonded to the IC chip and the substrate following the manufacturing process of the IC card shown in FIG. 4. FIG. 5 is a cross-sectional view showing a state in which hot pressing is performed on the manufactured inlet and the plastic sheet disposed on both surfaces of the inlet following the manufacturing process of the IC card shown in FIG. 4.

  Hereinafter, embodiments in which a portable electronic device according to the present invention is applied to an IC card will be described in detail with reference to the drawings. In this embodiment, the IC card is a non-contact IC card.

  As shown in FIGS. 1, 2, and 3, the IC card 1 includes an inlet 2 as an IC module and two overlay sheets 3. The inlet 2 includes a substrate 11, an electrode pattern 12, an antenna coil 15, an IC chip 16, a conductive first adhesive 18, a second adhesive 19, and a reinforcing plate 20.

  The substrate 11 is formed in a card shape. The substrate 11 is formed of an insulating material such as PET (polyethylene terephthalate resin), PVC (polyvinyl chloride), or paper. The electrode pattern 12 is formed on the substrate 11.

  The antenna coil 15 is for wireless communication with a communication device (not shown). The antenna coil 15 is formed on the substrate 11. One end of the antenna coil 15 is connected to one electrode pattern 12, and the other end of the antenna coil 15 is connected to another one electrode pattern 12.

  In this embodiment, the electrode pattern 12 and the antenna coil 15 are integrally formed of the same conductive material. Here, the electrode pattern 12 and the antenna coil 15 are made of aluminum.

  The IC chip 16 is mounted on the substrate 11. In this embodiment, the IC chip 16 is a large scale integrated circuit (LSI) IC chip. The thickness of the IC chip 16 is 50 μm to 100 μm. The IC chip 16 has protruding electrodes (bumps) 17. The protruding electrodes 17 are provided at four corners on one surface side of the IC chip 16. The protruding electrode 17 is positioned to face the electrode pattern 12.

  The first adhesive 18 is applied on the substrate 11 and the electrode pattern 12 and is interposed between the substrate 11 and the IC chip 16. The first adhesive 18 is formed beyond the outer edge of the IC chip 16.

  The IC chip 16 is bonded to the substrate 11 and the electrode pattern 12 by the first adhesive 18. Although not shown, the electrode pattern 12 and the protruding electrode 17 are electrically connected via conductive particles dispersed in the first adhesive 18. A circuit is formed by this connection, and it is possible to communicate with the outside through the antenna coil 15 in a non-contact manner.

  The reinforcing plate 20 is disposed on the opposite side of the substrate 11 with respect to the IC chip 16. The size of the reinforcing plate 20 is larger than the IC chip 16. The reinforcing plate 20 reinforces the mechanical strength of the inlet 2.

  The second adhesive 19 is applied on the IC chip 16 and is interposed between the IC chip 16 and the reinforcing plate 20. The second adhesive 19 is formed beyond the outer edge of the reinforcing plate 20. The reinforcing plate 20 is joined to the substrate 11, the electrode pattern 12, the first adhesive 18 and the IC chip 16 by the second adhesive 19.

Here, the second adhesive 19 has a lower elastic modulus than the first adhesive 18. The elastic modulus of the first adhesive 18 is 3000 MPa or more, and the elastic modulus of the second adhesive 19 is 10 MPa or less. The first adhesive 18 is formed by applying a highly elastic adhesive having a high elastic modulus after curing. The second adhesive 19 is formed by applying a low elastic adhesive having a low elastic modulus after curing.
As described above, the inlet 2 is formed.

Two overlay sheets 3 cover both sides of the inlet 2. The overlay sheet 3 is made of, for example, plastic as an insulating material. The inlet 2 and the two overlay sheets 3 are welded by, for example, a hot press.
As described above, the IC card 1 is formed.

  The IC card 1 receives the magnetic lines of force supplied via the antenna of the communication device via the antenna coil 15 and converts them into electric power, operates the CPU of the IC chip 16 with this electric power, and uses the remaining electric power for the communication device. Returns a response. Thus, the IC card 1 performs data communication with the communication device in a non-contact manner.

Next, a method for manufacturing the IC card 1 will be described.
As shown in FIGS. 4 and 5, first, a substrate 11 to which an aluminum foil is attached is prepared. Here, the board | substrate 11 with which the aluminum foil with resin which is not shown in figure was affixed is prepared. An aluminum foil having a thickness equal to the thickness of the electrode pattern 12 was used.

  Next, the aluminum foil is patterned by selectively etching away the aluminum foil using a photoetching method. That is, the electrode pattern 12 and the antenna coil 15 are formed by removing a part of the aluminum foil. In addition, the electrode pattern 12 and the antenna coil 15 should just be formed with the manufacturing method generally known.

  Subsequently, a conductive highly elastic adhesive is applied on the substrate 11 and the electrode pattern 12. Thereafter, the protruding electrode 17 of the IC chip 16 is opposed to the electrode pattern 12, and the IC chip 16 is attached to the substrate 11 and the electrode pattern 12.

  Thereafter, the substrate 11 to which the IC chip 16 is attached is transferred to the pressurization / heat treatment unit 30, and the substrate 11 is placed on the cradle 31 of the pressurization / heat treatment unit 30. Subsequently, the processing head 32 of the pressurizing / heating processing unit 30 facing the IC chip 16 is lowered to press and heat the IC chip 16 from the upper side.

  Thereby, the protruding electrode 17 of the IC chip 16 is pressed against the electrode pattern 12, and the highly elastic adhesive is cured. The cured high elastic adhesive becomes the first adhesive 18 having a high elastic modulus. The IC chip 16 is bonded to the substrate 11 and the electrode pattern 12 by the first adhesive 18. The protruding electrode 17 is electrically connected to the electrode pattern 12 through conductive particles dispersed in the first adhesive 18. By one thermocompression bonding method, physical joining and electrical connection are simultaneously performed.

  Next, as shown in FIG. 6, a low elastic adhesive is applied on the IC chip 16. Thereafter, the reinforcing plate 20 is opposed to the IC chip 16, and the reinforcing plate 20 is attached to the IC chip 16.

  Subsequently, the substrate 11 on which the reinforcing plate 20 is attached is transferred to the pressurization / heat treatment unit 30, and the substrate 11 is placed on the cradle 31 of the pressurization / heat treatment unit 30. Subsequently, the processing head 32 of the pressurizing / heating unit 30 facing the reinforcing plate 20 is lowered to press and heat the reinforcing plate 20 from the upper side.

Thereby, the reinforcing plate 20 is pressed against the IC chip 16, and the low elastic adhesive is cured. The cured low elastic adhesive becomes the second adhesive 19 having a low elastic modulus. The reinforcing plate 20 is bonded to the substrate 11, the electrode pattern 12, the IC chip 16, and the first adhesive 18 by the second adhesive 19.
The inlet 2 is produced by the above process.

Then, as shown in FIG. 7, a plastic sheet is arrange | positioned to both surfaces of the produced inlet 2, respectively. Next, the laminated structure inlet 2 and the plastic sheet are hot-pressed. Thereby, the inlet 2 and the plastic sheet are welded. The plastic sheet becomes the overlay sheet 3.
The IC card 1 is completed through the above steps.

  According to the IC card 1 configured as described above, the inlet 2 is interposed between the substrate 11, the IC chip 16 disposed opposite to the substrate 11, the substrate 11 and the IC chip 16, and the substrate 11 and the IC chip. The first adhesive 18 that joins 16, the reinforcing plate 20 disposed on the opposite side of the substrate 11 with respect to the IC chip 16, and the IC chip 16 and the reinforcing plate 20 are interposed between the IC chip 16 and the reinforcing plate 20. 2nd adhesive agent 19 which joins.

  The second adhesive 19 has a lower elastic modulus than the first adhesive 18. Since the second adhesive 19 serves as a buffer material, even if stress is applied to the reinforcing plate 20, the second adhesive 19 can absorb the stress and relieve the stress transmitted to the IC chip 16. it can. For this reason, the crack and crack which generate | occur | produce in IC chip 16 can be suppressed. The above effect can be obtained when the elastic modulus of the second adhesive 19 is 10 MPa or less.

  The first adhesive 18 has a higher elastic modulus than the second adhesive 19. For this reason, generation | occurrence | production of bulk destruction can be suppressed and the 1st adhesive agent 18 can hold | maintain the connection state of the protruding electrode 17 and the electrode pattern 12. FIG. That is, since the high electrical connection reliability can be obtained by the first adhesive 18, the function (wireless communication function or the like) as an IC card can be maintained. The above effect can be obtained when the elastic modulus of the first adhesive 18 is 3000 MPa or more.

The second adhesive 19 is formed beyond the outer edge of the reinforcing plate 20. Even if stress is applied to the reinforcing plate 20, the stress can be dispersed in a wider range by the second adhesive 19, so that concentration of stress on the IC chip 16 can be suppressed.
From the above, it is possible to obtain the IC card 1 that can suppress damage to the IC chip.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

For example, the electrode pattern 12 and the protruding portion 13 may be formed of a metal foil other than an aluminum foil, such as a copper foil.
The present invention is not limited to the IC card 1 but can be applied to various IC cards manufactured using flip chip mounting technology such as a thermocompression bonding method. In addition, the IC module of the present invention is not limited to an inlet, and can be applied to various IC modules. Furthermore, the portable electronic device of the present invention is not limited to an IC card, and can be applied to various portable electronic devices. Examples of the portable electronic device include a portable electronic device that includes an IC module and a main body that houses the IC module. Examples of the main body include an IC card main body.

  DESCRIPTION OF SYMBOLS 1 ... IC card, 2 ... Inlet, 3 ... Overlay sheet, 11 ... Board | substrate, 12 ... Electrode pattern, 15 ... Antenna coil, 16 ... IC chip, 17 ... Projection electrode, 18 ... 1st adhesive agent, 19 ... 2nd adhesion | attachment Agent, 20 ... reinforcing plate.

Claims (4)

A substrate,
An IC chip disposed opposite to the substrate;
A first adhesive interposed between the substrate and the IC chip and joining the substrate and the IC chip;
A reinforcing plate disposed on the opposite side of the substrate to the IC chip;
A second adhesive that is interposed between the IC chip and the reinforcing plate, has a lower elastic modulus than the first adhesive, and joins the IC chip and the reinforcing plate. Electronic equipment. The elastic modulus of the first adhesive is 3000 MPa or more,
The portable electronic device according to claim 1, wherein the elastic modulus of the second adhesive is 10 MPa or less.   2. The portable electronic device according to claim 1, wherein the second adhesive is formed beyond an outer edge of the reinforcing plate, covers the IC chip, and is bonded to the substrate. A substrate, an IC chip disposed opposite to the substrate, a first adhesive interposed between the substrate and the IC chip and joining the substrate and the IC chip, and on the opposite side of the substrate from the IC chip An IC comprising: a reinforcing plate disposed; and a second adhesive interposed between the IC chip and the reinforcing plate, having a lower elastic modulus than the first adhesive and joining the IC chip and the reinforcing plate. Module,
A portable electronic device comprising: a main body housing the IC module.

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