JP5029252B2 - Wireless IC device - Google Patents

Description

  The present invention relates to a wireless IC device, and more particularly, to a wireless IC device such as a non-contact wireless IC medium or a non-contact wireless IC tag used for an RF-ID (Radio Frequency Identification) system.

  Conventionally, various wireless IC devices on which a wireless IC chip is mounted have been proposed.

For example, in Patent Document 1, as shown in the cross-sectional view of FIG. After mounting the IC chip 109, the adhesive sheet 111 is brought into close contact as shown in the cross-sectional view of FIG. 6B, and the release sheet 101 is peeled off as shown in the cross-sectional view of FIG. 6C. A contactless wireless IC medium is disclosed.
JP 2002-298109 A

  In this non-contact type wireless IC medium, an adhesive sheet 111 is attached to an article. At this time, since the wireless IC chip 109 is only mounted on the adhesive sheet 111, the wireless IC chip 109 is projected to the outside and is exposed and attached to the outer surface of the article. . The wireless IC chip 109 exposed to the outside has a high risk of falling off and being damaged due to physical contact from the outside. In particular, a part of the wiring portion connected to the wireless IC chip 109 in the antenna portion 103 is in a suspended state, is easily broken (disconnected), and has a generally low joint reliability.

  Further, the wireless IC chip 109 and the adhesive sheet 111 on which the antenna portion 103 is formed are directly joined. When the adhesive sheet 111 is attached to the adherend, if the surface of the adherend has irregularities or curved surfaces, the wireless IC chip 109 must follow the deformation of the adhesive sheet 111, and the load on the wireless IC chip 109 is increased. Is big. Therefore, there is a high risk of destruction of the wireless IC chip 109, and there are many restrictions on the location where the adhesive sheet 111 is attached so that the wireless IC chip 109 does not break, and the structure is generally low in versatility.

  Further, since the wireless IC chip 109 protrudes to the outside and is used in an exposed state, if unnecessary electromagnetic waves enter the wireless IC chip 109 from the outside, the wireless IC chip 109 may malfunction or communication itself may not be performed. May become stable.

  In view of such circumstances, the present invention is intended to provide a wireless IC device that has high reliability of bonding of a wireless IC chip, has few restrictions on attachment points, does not malfunction, and has stable communication.

  In order to solve the above-described problems, the present invention provides a wireless IC device configured as follows.

  The wireless IC device includes (a) a power supply circuit board including at least one of a resonance circuit and / or a matching circuit including an inductance element, and having a recess formed on one main surface side, and (b) the power supply circuit board. A wireless IC chip mounted in the recess, (c) a base material arranged to cover the recess of the power supply circuit board, and (d) formed on the base material, A radiation plate electromagnetically coupled to at least one of the resonance circuit and the matching circuit; and (e) a first magnetic body disposed on at least a part of the surface of the feeder circuit board other than the recess.

  In the above configuration, the wireless IC chip is disposed in the recess of the power supply circuit board, and the recess is covered with the base material. The wireless IC chip is surrounded and protected by a power supply circuit board and a base material, and external impact is not directly applied to the wireless IC chip. Therefore, it is possible to prevent the wireless IC chip from being damaged or broken due to an impact such as dropping.

  In addition, by arranging a magnetic body in a portion other than the electromagnetic field coupling portion between the power supply circuit board and the radiation plate, electromagnetic waves reaching the wireless IC chip through the power supply circuit board from the outside of the wireless IC device are absorbed, and wireless It is possible to prevent malfunction of the IC chip and stabilize communication between the wireless IC chip and the reader / writer.

  Preferably, the concave portion of the power supply circuit board has a bottom surface facing the base material, and a side surface extending between the bottom surface and the one main surface of the power supply circuit board. The wireless IC chip is mounted on the bottom surface of the recess of the power supply circuit board. A second magnetic body disposed on a surface of the wireless IC chip facing the base material and a surface of the wireless IC chip facing the side surface of the recess of the feeder circuit board;

  According to the above configuration, the electromagnetic wave that has passed from the outside of the wireless IC device, passed through the base material, and reached the concave portion of the feeder circuit board is prevented from entering the wireless IC chip by the second magnetic body. Therefore, it is possible to expand the range of blocking unnecessary electromagnetic waves from the outside and more reliably prevent malfunction of the wireless IC chip.

  Preferably, a third magnetic body disposed between the bottom surface of the concave portion of the power supply circuit board and the wireless IC chip is provided.

  In this case, the wireless IC chip can be almost completely covered with the second and third magnetic bodies, and malfunction of the wireless IC chip due to the entry of electromagnetic waves can be prevented more reliably.

  Preferably, the radiation plate is formed on a main surface of the base material on the side far from the feeder circuit board.

  Since the radiation plate and the feeder circuit board are electromagnetically coupled, the radiation plate and the feeder circuit may not be arranged on the same side of the base material. When a wireless IC device is attached to an article so that the power supply circuit board is sandwiched between the article and the base material, the power supply circuit board can be covered and protected by the base material, and the radiation plate is a wireless IC device. Therefore, the radiation characteristics can be improved.

  Preferably, at least the first magnetic body is a sheet-like magnetic body sheet containing a magnetic material.

  In this case, the surface of the power supply circuit board can be easily and completely covered by covering the surface of the power supply circuit board with the magnetic sheet.

  Preferably, at least one of the first, second, and third magnetic bodies is a resin containing a magnetic material.

  In this case, the magnetic material can be easily arranged by utilizing the fluidity of the resin. In particular, the third magnetic body disposed between the bottom surface of the recess of the power feeding circuit and the wireless IC chip can be easily disposed.

  In a preferred aspect, at least one of the first, second and third magnetic bodies contains ferrite.

  Although there are few examples of electronic parts using ferrite for shielding electromagnetic waves that cause electromagnetic interference, a magnetic material can be easily formed by using philite.

  Preferably, the base material is formed of a flexible substrate.

  When a flexible substrate such as a PET film is used as a base material that covers the recess of the power supply circuit board, even if there is a warp or the like on the power supply circuit board, the recess of the power supply circuit board is securely covered, and the power supply circuit board is reliably Can be joined.

  Preferably, the feeder circuit board is formed of a multilayer board in which a plurality of layers are laminated.

  In this case, the feeder circuit board can be reduced in size by incorporating passive elements inside the multilayer board.

  According to the present invention, the bonding reliability of the wireless IC chip is high, and there are few restrictions on the places to be attached. In addition, the magnetic body disposed along the surface of the power supply circuit board can prevent malfunction of the wireless IC chip due to unnecessary electromagnetic waves from the outside, and communication is stabilized.

  Hereinafter, examples of the present invention will be described with reference to FIGS.

  First Embodiment A wireless IC device 10 according to a first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the wireless IC device 10. FIG. 2A is a cross-sectional view taken along line AA in FIG. FIG. 2B is a cross-sectional view taken along line BB in FIG.

  As shown in FIG. 1, in the wireless IC device 10, a recess 14 is formed in the power feeding circuit board 12, and a wireless IC chip 18 is housed and mounted in the recess 14. A sheet-like base material 20 on which a radiation plate 22 is formed is joined to the feeder circuit board 12. The base material 20 is joined to the power feeding circuit board 12 so as to cover the recess 14 of the power feeding circuit board 12. As for the base material 20, the lower surface 20b on the opposite side to the electric power feeding circuit board 12 is affixed on the goods not shown.

  For example, in the RF-ID system, a wireless IC device 10 affixed to an article is communicated with the wireless IC chip 18 via the radiation plate 22 using a reader / writer (not shown) from the outside. Read stored data without contact.

  As shown in FIGS. 1 and 2A, the surface of the feeder circuit board 12 is a portion excluding a portion where an insulating bonding material 11 described later is disposed and a portion where a concave portion 14 is formed, that is, A resin 24 containing a magnetic material such as ferrite is applied as a first magnetic material to the upper surface 12a and the side surface 12s. The resin 24 absorbs electromagnetic waves that are about to enter the power supply circuit board 12 from the outside of the wireless IC device 10 before reaching the wireless IC chip 18.

  The wireless IC chip 18 is coated with a resin 26 containing a magnetic material such as ferrite as a second magnetic material on the surface 18b and the side surface 18s facing the base material 20 on the opposite side of the mounting surface 18a. ing. The resin 26 absorbs electromagnetic waves that have passed through the base material 20 and reached the recess 14 of the power supply circuit board 12 from the outside of the wireless IC device 10 before entering the wireless IC chip 18.

  Due to the electromagnetic wave absorbing action of these resins 24 and 26, the malfunction of the wireless IC chip 18 due to noise or the like is eliminated, and the communication with the reader / writer or the like is stabilized.

  The power supply circuit board 12 is a multilayer substrate in which a plurality of layers of ceramics or resins are laminated, for example, and a power supply circuit including an inductance element is formed in the inside thereof by an in-plane conductor 13a and an interlayer connection conductor 13b. For example, in the case of ceramic, it is LTCC, HTCC, or ferrite, and in the case of resin, it is LCP or the like. By incorporating a passive element inside the multilayer substrate, the feeder circuit substrate can be reduced in size.

  The power feeding circuit includes a resonance circuit having a resonance frequency corresponding to the operating frequency at which the wireless IC chip 18 operates. The feeder circuit may include a matching circuit that matches the characteristic impedance between the radiation plate 22 and the wireless IC chip 18.

  Note that the power supply circuit board may be a single-layer board. Further, the power feeding circuit may be formed only on the surface of the power feeding circuit board.

  As shown in FIGS. 1 and 2B, at least one recess 14 is formed on the upper surface 12 a side of the power supply circuit board 12, and the coupling electrode 16 of the power supply circuit is exposed at the crosspiece surrounding the recess 14. is doing. The coupling electrode 16 may be disposed only on a part of the four sides of the crosspiece that surrounds the recess 14.

  As shown in FIG. 1, the wireless IC chip 18 is formed by flip chip bonding or Ag nano bonding using Au bumps, Ag bumps, solder bumps, or the like on the electrodes 15 exposed on the bottom surface 14a of the recesses 14 of the power supply circuit board 12. And are mounted via bumps 19. The bonding may be performed using die bonding or wire bonding, or by combining these bondings.

  Although not shown, in order to further strengthen the bonding reliability of the wireless IC chip 18, the gap 23 between the wireless IC chip 18 and the power feeding circuit substrate 12 is filled with an underfill resin, You may strengthen holding | maintenance of the electrical connection with the electric power feeding circuit board 12. FIG.

  The base material 20 has a sheet shape, and for example, an insulating material such as paper, PET film, or flexible resin is used.

  It is preferable to form the base material 20 with a flexible substrate such as a PET film because impact resistance and environmental resistance can be improved. That is, since the flexible substrate can cover the power supply circuit board 12 of any shape, even when the power supply circuit board 12 is warped, the concave portion 14 of the power supply circuit board 12 is securely covered, and the power supply circuit board 12 is covered. 12 can be reliably bonded. In addition, the wireless IC device 10 can be attached to an article having irregularities or undulations on the surface.

  In the base material 20, a radiation plate 22 is formed of a conductive material on an upper surface 20 a that faces the feeder circuit board 12. The radiation plate 22 is formed by, for example, printing of Ag particle-containing resin, fine wiring by ink jet or photolithography, or the like.

  The radiation plate 22 is formed at a position covering the concave portion 14 of the power supply circuit board 12, a position facing the coupling electrode 16 of the power supply circuit board 12, and an outside of a region facing the power supply circuit board 12. Are coupled to the coupling electrode 16 by an electromagnetic field. The radiation plate 22 and the coupling electrode 16 may be coupled by an electromagnetic field so that the radiation plate 22 does not face the coupling electrode 16.

  When the radiation plate 22 is formed on the same side as the feeder circuit board 12 of the principal surfaces 12a and 12b of the base material 20, that is, the upper surface 20a, the electromagnetic field between the coupling electrode 16 and the radiation plate 22 of the feeder circuit board 12 is formed. It is easy to stabilize the bond.

  The radiation plate 22 is formed so as to include an appropriate antenna shape, and radiates and receives, for example, a UHF band transmission signal supplied from the coupling electrode 16 of the power supply circuit board 12 through electromagnetic coupling into the air. The received signal is supplied to the power supply circuit of the power supply circuit board 12 through electromagnetic coupling.

  Between the lower surface 12b of the feeder circuit board 12 and the upper surface 20a of the base material 20 or the radiation plate 22, an insulating adhesive sheet (adhesive thin film on the adhesive surface of a commercially available seal), a bonding material 11 such as an adhesive is interposed. Are joined. The coupling electrode 16 exposed to the lower surface 12b of the feeder circuit board 12 and the radiation plate 22 are coupled by an electromagnetic field via the insulating bonding material 11, and the coupling electrode and the radiation plate 22 of the feeder circuit board 12 are Does not conduct in direct current.

  When the radiation plate 22 and the coupling electrode 16 of the feeder circuit board 12 are coupled by an electromagnetic field, the feeder circuit board is more electrically coupled than when the radiation plate 22 and the coupling electrode 16 of the feeder circuit board 12 are electrically connected by a conductor. Since the accuracy of alignment between the radiating plate 12 and the radiation plate 22 can be relaxed, the manufacturing becomes easy and mass production is easy. Further, since the wireless IC chip 18 is insulated from the radiation plate 22 by an insulating bonding material and has no direct current conduction, the wireless IC chip 18 can be prevented from being destroyed by static electricity from the radiation plate 22 or the like. it can.

  The wireless IC chip 18 of the wireless IC device 10 is mounted in the recess 14 of the power supply circuit board 12, covered with the base material 20, and not exposed to the outside, so that it does not receive physical contact from the outside. Further, since the wireless IC chip 18 is not in contact with the base material 20 or the radiation plate 22, impact or deformation from the base material 20 side is not directly applied to the wireless IC chip 18. Therefore, there is a low risk that the wireless IC chip 18 is dropped and damaged, and the bonding reliability of the wireless IC chip 18 is high.

  Further, even if the base material 20 is deformed when being attached to the uneven surface or curved surface of the article, the wireless IC chip 18 mounted in the recess 14 of the power supply circuit board 12 needs to follow the deformation of the base material 20. Absent. Therefore, the wireless IC device 10 is less versatile and has high versatility.

  Furthermore, since the power supply circuit board 12 is covered with the sheet-like base material 20, it has a cushion effect and is resistant to external impact.

  Example 2 As shown in the cross-sectional view of FIG. 3, the wireless IC device 10 a of Example 2 is configured in substantially the same manner as Example 1. Below, it demonstrates centering around difference with Example 1, and uses the same code | symbol for the same component as Example 1. FIG.

  As shown in FIG. 3, the wireless IC device 10 a is different from the first embodiment in that the coupling electrode 16 a of the feeding circuit is arranged inside the feeding circuit board 12, and the coupling electrode 16 a is on the lower surface 12 b of the feeding circuit board 12. Not exposed. The coupling electrode 16a and the radiation plate 22 are coupled by an electromagnetic field. Since the coupling electrode 16a is not exposed to the outside, the bonding material 11 used for bonding the power supply circuit board 12 and the base material 20 may be conductive / insulating.

  <Example 3> As shown in the cross-sectional view of FIG. 4, the wireless IC device 10b of Example 3 includes, in addition to the configuration of Example 2, mounting of the bottom surface 14a of the recess 14 of the feeder circuit board 12 and the wireless IC chip 18. A resin 28 containing a magnetic material such as ferrite is filled between the surface 18a. As the third magnetic body, the resin 28 prevents electromagnetic waves from entering the wireless IC chip 18 from the mounting surface 18a side of the wireless IC chip 18. The periphery of the wireless IC chip 18 can be almost completely covered with the resins 26 and 28 including a magnetic material, and the malfunction of the wireless IC chip 18 due to the entry of electromagnetic waves can be prevented more reliably. The resin 28 between the bottom surface 14a of the recess 14 of the power supply circuit board 12 and the mounting surface 18a of the wireless IC chip 18 can also serve as an underfill resin. The retention of the dynamic connection can be strengthened.

  <Embodiment 4> As shown in the cross-sectional view of FIG. 5, the wireless IC device 10c of Embodiment 4 is configured in substantially the same manner as the wireless IC device 10b of Embodiment 3.

  In the wireless IC device 10b of the third embodiment shown in FIG. 4, the radiation plate 22 is formed on the upper surface 20a of the base member 20, whereas in the wireless IC device 10c of the fourth embodiment, as shown in FIG. In addition, the radiation plate 22 is formed on the lower surface 20 b of the substrate 20.

  In the wireless IC device 10c according to the fourth embodiment, when the lower surface 20b of the base material 20 is attached to an article (not shown), the radiation plate 22 comes into contact with the article. Therefore, the radiation characteristic can be improved by using the article as an antenna. .

  As shown in FIG. 5, in the wireless IC device 10 c according to the fourth embodiment, a resin 29 containing a magnetic material such as ferrite is disposed between the lower surface of the feeder circuit board 12 and the upper surface 20 a of the base material 20. The power supply circuit board 12 and the base material 20 are joined. The resin 29 can be formed by applying and filling simultaneously with the resin 24 covering the upper surface 12a and the side surface 12s of the power supply circuit board 12 and the resins 26 and 28 covering the periphery of the wireless IC chip 18.

  <Summary> As described above, the wireless IC chip is disposed in the concave portion of the power supply circuit board, and the concave portion is covered with the base material. There is a low risk of dropping or breaking, and the bonding reliability of the wireless IC chip is high.

  In addition, when the peripheral part of the sheet-like base material of the wireless IC device is attached to an article, the wireless IC chip mounted in the recess of the power supply circuit board does not need to follow the deformation of the base material. There are few restrictions, and versatility is high.

  In addition, by disposing a magnetic body around the wireless IC device, malfunction of the wireless IC chip due to noise or the like can be prevented, and communication between the wireless IC chip and the reader / writer can be stabilized.

  The present invention is not limited to the above-described embodiment, and can be implemented with various modifications.

  For example, the radiation plate and the feeder circuit board may be electromagnetically coupled using not only electromagnetic waves but only electric fields or magnetic fields. Moreover, although the embodiment in which the resin containing the magnetic material is in contact with the power supply circuit board and the wireless IC chip has been described, other members may be disposed between them or a space may be provided.

  Further, the upper surface of the feeder circuit board may be attached to the article. In that case, since the radiation plate is arranged toward the outside of the article, the radiation characteristics can be improved.

It is sectional drawing of a wireless IC device. Example 1 It is sectional drawing of a wireless IC device. Example 1 It is sectional drawing of a wireless IC device. (Example 2) It is sectional drawing of a wireless IC device. (Example 3) It is sectional drawing of a wireless IC device. Example 4 It is sectional drawing which shows the manufacturing process of a wireless IC device. (Conventional example)

Explanation of symbols

10, 10a, 10b, 10c Wireless IC device 12 Feed circuit board 14 Recess 18 Wireless IC chip 20 Base material 22 Radiation plate 24 Resin (first magnetic body)
26 Resin (second magnetic body)
28 Resin (third magnetic body)
29 Resin (first magnetic body)

Claims (9)

A power supply circuit board including at least one of a resonance circuit and / or a matching circuit including an inductance element, and having a recess formed on one main surface side;
A wireless IC chip mounted in the recess of the feeder circuit board;
A base material disposed so as to cover the concave portion of the feeder circuit board;
A radiation plate formed on the substrate and electromagnetically coupled to at least one of the resonance circuit and the matching circuit of the feeder circuit board;
A first magnetic body disposed on at least a part of the surface of the feeder circuit board other than the recess;
A wireless IC device comprising: The recess of the power supply circuit board has a bottom surface facing the base material, and a side surface extending between the bottom surface and the one main surface of the power supply circuit board,
The wireless IC chip is mounted on the bottom surface of the recess of the power supply circuit board,
A second magnetic body is disposed on a surface of the wireless IC chip that faces the base material and a surface of the wireless IC chip that faces the side surface of the recess of the power supply circuit board. The wireless IC device according to claim 1.   The wireless IC device according to claim 2, further comprising a third magnetic body disposed between the bottom surface of the recess of the power supply circuit board and the wireless IC chip.   4. The wireless IC device according to claim 1, wherein the radiation plate is formed on a main surface of the base material on a side far from the power supply circuit board.   The wireless IC device according to any one of claims 1 to 4, wherein at least the first magnetic body is a sheet-like magnetic sheet containing a magnetic material.   6. The wireless IC device according to claim 1, wherein at least one of the first, second, and third magnetic bodies is a resin containing a magnetic material. 7.   The wireless IC device according to claim 1, wherein at least one of the first, second, and third magnetic bodies includes ferrite.   The wireless IC device according to any one of claims 1 to 7, wherein the base material is formed of a flexible substrate.   The wireless IC device according to any one of claims 1 to 8, wherein the power supply circuit board is formed of a multilayer board in which a plurality of layers are laminated.

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