JP5029253B2 - 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.

  Moreover, since the antenna part 103 is substantially planar, directivity is not wide.

  In view of such a situation, the present invention intends to provide a wireless IC device that has high reliability of bonding of a wireless IC chip, has few restrictions on attachment points, and can widen the directivity of an antenna even if it is downsized. Is.

  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, and (c) a base material arranged to cover the one main surface of the feeder circuit board and the recess and at least a part of the side surface of the feeder circuit board; (D) a radiation plate formed on the base material, electromagnetically coupled to at least one of the inductance element, the resonance circuit, and the matching circuit of the feeder circuit board and covering at least a part of 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, the risk of the wireless IC chip falling off or being damaged due to physical contact from the outside is low, and the joining reliability of the wireless IC chip is high.

  Further, even when the base material is attached to the article and deformed, the wireless IC chip need not follow the deformation of the base material. As a result, restrictions on the location where the wireless IC device is attached can be reduced, and versatility can be improved.

  Further, when the wireless IC device is attached to the article such that the feeder circuit board is disposed on the article side, the base material is disposed on the opposite side of the article, and the feeder circuit board is sandwiched between the article and the substrate. The radiation plate for signal transmission / reception is arranged so as to protrude on the opposite side of the power supply circuit board and the article, that is, the outside of the wireless IC device. Therefore, even if the radiation plate is downsized to the same extent as the power supply circuit board. Radiation characteristics can be widened, and directivity design freedom is improved.

  Preferably, the radiation plate covers at least a part of the side surface of the feeder circuit board.

  In this case, the radiation characteristic can be made wider, and the directivity design freedom is further improved. Further, since the portion where the radiation plate covers the side surface of the power supply circuit board can be used for electromagnetic field coupling with the power supply circuit board, restrictions on electromagnetic field coupling are reduced, and the degree of freedom in design is improved.

  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 characteristic can be improved.

  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.

  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 recesses of the power supply circuit board, any shape of the power supply circuit board can be covered, and impact resistance and environmental resistance can be improved.

  The present invention provides an article with a wireless IC device to which the wireless IC device having any one of the above configurations is attached.

  In the article with a wireless IC device, a main surface of the base material of the wireless IC device on the power feeding circuit board side is attached to the article, and the power feeding circuit board is disposed between the base material and the article.

  In this article, the power supply circuit board can be covered and protected with a base material, and the radiation characteristics are improved because the radiation plate faces the outside of the wireless IC device.

  According to the present invention, it is possible to prevent an external impact or the like from being directly applied to the wireless IC chip, and it is possible to widen the directivity of the antenna.

  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. As shown in FIGS. 1 and 2, the base material 20 is bent so that the center portion covers the upper surface 12 a, the concave portion 14, and the side surface 12 s of the feeder circuit board 12. The peripheral portion 20s of the base material 20 is bent so as to be flush with the lower surface 12b of the power supply circuit board 12, and is attached to an unillustrated article. At this time, the lower surface 12b of the feeder circuit board 12 contacts the article.

  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.

  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 bonded to the crosspiece surrounding the recess 14. The working electrode 17 is exposed. The coupling electrode 16 may be disposed only on a part of the four sides of the crosspiece that surrounds the recess 14. Further, the bonding electrode 17 may be omitted.

  As shown in FIG. 1, the wireless IC chip 18 is flip-chip bonded or Ag nano-bonded using Au bumps, Ag bumps, solder bumps, or the like to the electrodes 15 exposed on the bottom surface 14 a of the recess 14 of the power supply circuit board 12. Is mounted via the bonding material 19. The bonding may be performed using die bonding or wire bonding, or by combining these bondings. The upper surface 18 a of the wireless IC chip 18 is covered with the base material 20 or the radiation plate 22 with a gap 23.

  Although not shown, in order to further strengthen the bonding reliability of the wireless IC chip 18, an underfill resin is filled in the gap 19 s between the wireless IC chip 18 and the power supply circuit substrate 12, 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 a lower surface 20 b facing 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 recess 14 of the power supply circuit board 12 and a position facing the coupling electrode 16 of the power supply circuit board 12. The radiation plate 22 is coupled to the coupling electrode 16 by an electromagnetic field. Yes. If the radiation plate 22 and the coupling electrode 16 can be coupled by an electromagnetic field, the radiation plate 22 may be configured not to face the coupling electrode 16.

  If the radiation plate 22 is formed on the main surface 20a, 20b of the base member 20 on the same side as the feeder circuit board 12, that is, the lower surface 20b, 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 upper surface 12a of the feeder circuit board 12 and the lower surface 20b of the base material 20 or the radiation plate 22, a bonding material (not shown) such as an insulating pressure-sensitive adhesive sheet (adhesive thin film on the pressure-sensitive adhesive surface of a commercially available seal) or an adhesive. It is joined through. The coupling electrode 16 exposed to the upper surface 12a of the power supply circuit board 12 and the radiation plate 22 are coupled by an electromagnetic field via an insulating bonding material, and the coupling electrode of the power supply circuit board 12 and the radiation plate 22 are DC. Does not conduct.

  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 peripheral portion 20 s of 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 concave portion 14 of the power supply circuit board 12 is not deformed by the base material 20. There is no need to follow. 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.

  The wireless IC device 10 is used in a state where the lower surface 20b of the peripheral portion 20s of the base material 20 is attached to an article. At this time, the power supply circuit board 12 is sandwiched between the article and the base material 20, and the radiation plate 22 involved in signal transmission / reception is disposed on the upper surface 12a side of the power supply circuit board 12, that is, on the opposite side of the article. It is arranged in the position away from. Therefore, compared with the case where the radiation plate is disposed between the article and the power supply circuit board, the radiation characteristic can be widened even if the radiation plate 22 is downsized to the same extent as the power supply circuit board 12, and the directivity can be increased. Design flexibility is also improved.

  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 radiation plate 22 a formed on the base material 20 is not only on the upper surface 12 a and the concave portion 14 of the feeder circuit board 12 but also on the portion 22 s of the feeder circuit board 12 that faces the side surface 12 s. Is formed.

  Thus, when the radiation plate 22 covers the side surface 12s of the feeder circuit board 12, the radiation characteristic of the radiation plate 22a becomes wider and the design freedom of directivity is further improved.

  In addition, unlike the first embodiment, the wireless IC device 10 a includes a coupling electrode 16 a for the feeding circuit disposed inside the feeding circuit board 12, and the coupling electrode 16 a is not exposed on the upper surface 12 a of the feeding circuit board 12. 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 used for bonding the power supply circuit board 12 and the base material 20 may be conductive / insulating.

  A portion 22s of the radiation plate 22 facing the side surface 12s of the power supply circuit board 12 can be coupled to the coupling electrode 16a in the power supply circuit board by an electromagnetic field. For this reason, restrictions on electromagnetic field coupling are reduced, and the degree of freedom in design is improved.

  Example 3 As shown in the cross-sectional view of FIG. 4, the wireless IC device 10b of Example 3 has substantially the same configuration as the wireless IC device 10a of Example 2.

  Unlike the wireless IC device 10a of the second embodiment, the wireless IC device 10b of the third embodiment has a radiation plate 22b formed on the upper surface 20a of the base 20 on the side opposite to the power supply circuit board 12. Even if the radiation plate 22b is not formed on the lower surface 20b of the base member 20 on the same side as the feeder circuit board 12, the radiation plate 22b is coupled to the coupling electrode 16a of the feeder circuit board 12 by an electromagnetic field. The radiation plate 22b has a portion 22t that covers the side surface 12s of the feeder circuit board 12 as in the first embodiment.

  The wireless IC device 10b of the third embodiment can improve the radiation characteristics because the radiation plate 22b faces the outside of the wireless IC device 10b. The coupling electrode 16a may be exposed on the crosspiece surface surrounding the recess 14 as described in the first embodiment.

  <Example 4> The article | item 1 with a wireless IC device of Example 4 is demonstrated referring FIG.

  As shown in the cross-sectional view of FIG. 5, in the article 1 with the wireless IC device of Example 4, the peripheral portion 22 s of the base material 20 of the wireless IC device 10 b of Example 3 is attached to the article 2 through the adhesive layer 4. It is attached. For the adhesive layer 4, the same material as the bonding material for bonding the base material 20 and the feeder circuit board 12 may be used, or a different material may be used. In the case where the wireless IC device 10b and the article 1 with the wireless IC device are continuously manufactured, the process can be simplified by using the same bonding material.

  <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.

  When the wireless IC device is attached to an article, the radiation plate is arranged outside (the side opposite to the article) from the power supply circuit board, so the radiation plate is arranged inside (the article side) from the power supply circuit board. Compared to the case, the radiation characteristics are improved even if the radiation plate is downsized to the same extent as the feeder circuit board. Furthermore, if the radiation plate covers from the upper surface to the side surface of the feeder circuit board, the radiation characteristics can be made wider, and the degree of freedom in design of directivity is further improved.

  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.

  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, you may make it a base material or a radiation plate and a radio | wireless IC chip contact.

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 which shows the state by which the wireless IC device was affixed on the articles | goods. Example 4 It is sectional drawing which shows the manufacturing process of a wireless IC device. (Conventional example)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Article with wireless IC device 2 Article 10, 10a, 10b Wireless IC device 12 Feeding circuit board 12a Upper surface (one main surface)
12b Lower surface 12s Side surface 14 Recess 16, 16a Coupling electrode 18 Wireless IC chip 20 Base material 22, 22a, 22b Radiation plate

Claims (6)

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 one main surface and the concave portion of the feeder circuit board and at least a part of a side surface of the feeder circuit board;
A radiation plate formed on the substrate, electromagnetically coupled to at least one of the resonance circuit and the matching circuit of the feeder circuit board, and covering at least a part of the recess;
A wireless IC device comprising:   The wireless IC device according to claim 1, wherein the radiation plate covers at least a part of the side surface of the feeder circuit board.   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.   4. The wireless IC device according to claim 1, wherein the power supply circuit substrate is formed of a multilayer substrate in which a plurality of layers are laminated. 5.   The wireless IC device according to any one of claims 1 to 4, wherein the base material is formed of a flexible substrate.   The main surface of the base material of the wireless IC device according to any one of claims 1 to 5 on the power supply circuit board side is attached to an article, and the power supply circuit board is interposed between the base material and the article. An article with a wireless IC device, wherein:

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