JP2005316580A - Electronic apparatus and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily miniaturizable electronic apparatus and its manufacturing method. <P>SOLUTION: An IC chip 41 and an antenna coil 61 are mounted on a surface S of a board 11. The IC chip 41 has a communication circuit for controlling communication via the antenna coil 61. A sealing material (a mold) 53 is provided around the IC chip 41. The antenna coil 61 is electrically connected to the IC chip 41. The antenna coil 61 is arranged in the sealing material 53 in the attitude of encircling the IC chip 41 in view from the direction perpendicular to the surface S. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic device having a function of communicating with another device, and more particularly, to a technique for mounting an antenna coil used for communication in this type of electronic device on a substrate.

Various electronic devices having a function of communicating with other devices wirelessly have been widely used. For example, under a technology using RFID (Radio Frequency Identification) for identifying a user or an article, an IC tag (RFID) in which various data is stored and the IC tag are contactless. A device for writing and reading data (hereinafter referred to as “reader / writer”) is used. Electronic devices such as IC tags and reader / writers are generally required to be small in terms of ensuring portability and reducing power consumption. In order to meet such a demand for miniaturization, for example, Patent Document 1 discloses a configuration in which scanning lines and data lines for displaying an image are also used as an antenna in an electronic device having a display function. . According to this configuration, the size can be reduced as compared with the configuration in which the antenna is provided independently from the scanning line and the data line.
Japanese Unexamined Patent Publication No. 7-46515 (paragraph 0034 and FIG. 1).

However, in the configuration disclosed in Patent Document 1, an antenna is arranged in a region where an image is displayed. Therefore, the antenna and an IC chip including a communication circuit that controls communication are separated from each other with a considerable distance. It will be arranged at the position. Therefore, there may arise a problem that noise is easily superimposed on a signal exchanged between the antenna and the IC chip. Further, when the scanning line or the data line is also used as an antenna, it is necessary to separate the pixel display driving signal and the wireless communication signal.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electronic device that can be easily downsized and a method for manufacturing the same.

  In order to solve the above-described problems, an electronic device according to the present invention includes a base material, an IC chip disposed on the base material, a sealing material that is bonded to the base material and seals the IC chip, and an IC chip. The antenna coil is disposed inside the sealing material in a surrounding form.

According to this configuration, since the antenna coil is disposed inside the sealing material so as to surround the IC chip, the antenna coil is disposed in comparison with the configuration in which the antenna coil is disposed in a region that does not overlap the sealing material. The space required for this can be reduced. The sealing material (so-called mold) in the present invention is sufficient if it covers a part of the IC chip and seals and protects the IC chip and the connection terminal to which the IC chip is electrically connected. It does not necessarily have to be completely covered throughout. Moreover, the base material in this invention does not necessarily need to be a plate-shaped member. For example, when the electronic device according to the present invention is applied to RFID, an IC chip can be directly arranged on various articles such as merchandise. In this case, the article on which the IC chip is arranged is used as a base material. Equivalent to. However, the substrate may be a substrate of an electronic device having a function of displaying an image. In this case, a large number of pixels and driving circuits for driving the pixels are arranged on the substrate. The pixel driving circuit may be provided in an IC chip having a communication circuit, or may be provided separately.

In the present invention, the function and operation of the IC chip surrounded by the antenna coil is not questioned. For example, in an electronic device having a function of displaying an image with pixels arranged on a substrate, an IC chip having a drive circuit or other control circuit for driving the pixels can be surrounded by an antenna coil.
However, if the antenna coil is connected to the IC chip and the IC chip includes a communication circuit that controls transmission / reception of data via the antenna coil, the IC chip including only circuits not related to communication is enclosed. Thus, the distance between the antenna coil and the communication circuit can be shortened as compared with the configuration in which the antenna coil is arranged, so that noise that can be superimposed on a signal transmitted and received between the antenna coil and the communication circuit is reduced. Can do.

  The substrate also includes a substrate on which a plurality of pixels are arranged, a first IC chip that has a drive circuit that supplies a drive signal to each pixel and is disposed on the substrate, and a communication circuit that controls transmission and reception of data. The present invention can also be applied to an electronic device having a second IC chip that is arranged and a sealing material that is bonded to a substrate and seals each IC chip. In this electronic apparatus, if an antenna coil is arranged inside the sealing material in a form surrounding the second IC chip and electrically connected to the second IC chip, the space required for the arrangement of the antenna coil is reduced. While reducing, it is possible to reduce noise of signals transmitted and received between the antenna coil and the communication circuit. The configuration of the pixel in the present invention is arbitrary, but typically, a configuration in which an electro-optical material is disposed in a gap between electrodes facing each other can be employed. This electro-optical material is a material for converting electrical energy such as current and voltage into optical action such as transmittance and luminance. For example, liquid crystal, OLED (Organic Light Emitting Diode) elements, plasma, and electrophoretic solutions are used. It is.

  An electronic device manufacturing method according to the present invention includes a chip placement step of placing an IC chip on a base material, an antenna placement step of placing an antenna coil so as to surround the IC chip, and depositing a sealing material on the base material. And a sealing step of encapsulating the antenna coil with the sealing material and sealing the IC chip. According to this method, the space required for arranging the antenna coil can be reduced for the same reason as in the electronic apparatus according to the present invention. Further, the antenna coil can be fixed to the equipment in the sealing process. Note that the order in which the chip placement step and the antenna placement step are performed is arbitrary. That is, the antenna arrangement process may be executed following the chip arrangement process, and conversely, the chip arrangement process may be executed after the antenna arrangement process.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings shown below, the dimensions and ratios of the respective parts are appropriately different from the actual ones.

<1. First Embodiment>
1 is an enlarged plan view showing the vicinity of a substrate on which an antenna coil is arranged in the electronic apparatus according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. The electronic device 10 in this embodiment is, for example, an IC tag, and includes a substrate (base material) 11, an IC chip 41 and an antenna coil 61 mounted on the substrate 11, as shown in FIGS. 1 and 2. Have. Among these, the board | substrate 11 is a plate-shaped member which has the surface S, such as a rigid board | substrate and a flexible board | substrate which has flexibility. The antenna coil 61 is a rectangular loop coil in which a conducting wire is wound once or a plurality of times so as to surround the IC chip 41 when viewed from a direction perpendicular to the surface S of the substrate 11. It functions as an antenna for receiving and transmitting radio waves to other devices. Instead of or in addition to radio communication, the antenna coil may be used for charging using the principle of electromagnetic induction. On the other hand, the IC chip 41 is an unpackaged chip (so-called bare chip), a communication circuit for controlling communication via the antenna coil 61, and a storage circuit for storing data used for communication. Is included. Among these, the communication circuit outputs the digital data obtained by demodulating the radio wave received by the antenna coil 61 to the storage circuit, and transmits the radio wave obtained by modulating the carrier wave with the digital data read from the storage circuit to the antenna. Transmit from coil 61.

  As shown in FIG. 2, the IC chip 41 is fixed to the surface S through the anisotropic conductive film 51 with the bonding surface 401 facing the substrate 11. Bumps (projection electrodes) 402 are formed on the bonding surface 401 so as to cover each of the input terminal and the output terminal connected to the communication circuit. On the other hand, on the surface S of the substrate 11, a wiring 63 having connection terminals 631 connected to the bumps 402 of the IC chip 41 and connection terminals 633 to which the respective ends of the conductive wires constituting the antenna coil 61 are connected is formed. Has been. As shown in FIG. 2, in a state where the bonding surface 401 of the IC chip 41 is bonded to the surface S by the adhesive 511 of the anisotropic conductive film 51, each connection terminal 631 and each bump 402 of the IC chip 41 are Electrical conduction is established through the conductive particles 512 dispersed in the adhesive 511. With this configuration, electrical continuity between each end of the antenna coil 61 and the communication circuit of the IC chip 41 is achieved.

  A sealing material (mold) 53 is bonded to the surface S of the substrate 11 on which the IC chip 41 and the antenna coil 61 are mounted. The sealing material 53 is made of, for example, a resin material such as silicone resin (silicone), and is formed so as to surround the IC chip 41 over the entire circumference when viewed from a direction perpendicular to the surface S of the substrate 11. Therefore, a portion where the bonding surface 401 and the surface S of the IC chip 41 face each other (more specifically, a portion where the bump 402 and the wiring 63 are electrically connected) is sealed and protected by the sealing material 53. According to this configuration, since the bonding surface 401 of the IC chip 41 is sealed by the sealing material 53 and isolated from the outside air, a situation where the bump 402 and the connection terminal 631 are corroded due to adhesion of moisture in the outside air is prevented. . The antenna coil 61 disposed around the IC chip 41 is enclosed by a sealing material 53. That is, the sealing material 53 covers the antenna coil 61 over its entire length. In the illustrated embodiment, the upper surface of the IC chip 41 is exposed from the sealing material 53, but the entire IC chip 41 may be surrounded by the sealing material 53. Further, a part of the antenna coil may be exposed from the sealing material. In this case, the sealing material is exclusively used for reinforcing the mechanical strength of the antenna coil.

  Thus, in this embodiment, since the antenna coil 61 is disposed inside the sealing material 53 formed around the IC chip 41, the antenna is located at a position away from the IC chip 41 and the sealing material 53. Compared to the configuration in which the coil 61 is arranged, the space required for the arrangement of the IC chip 41 and the antenna coil 61 can be reduced. Moreover, since the antenna coil 61 is sealed by the sealing material 53 and isolated from the outside air, corrosion of the antenna coil 61 due to the adhesion of moisture in the outside air is prevented. Further, since the antenna coil 61 is disposed so as to surround the IC chip 41 provided with the communication circuit, compared with the configuration in which the antenna coil 61 is disposed at a position separated from the IC chip 41 and the sealing material 53. The noise that can be superimposed on the signal exchanged between the antenna coil 61 and the IC chip 41 is reduced.

<2. Second Embodiment>
Next, a mode in which the present invention is applied to an electronic device having a function of displaying an image will be described. FIG. 3 is a plan view showing a configuration of a display panel mounted on the electronic apparatus according to the present embodiment, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. The display panel 20 is employed, for example, in a reader / writer that writes and reads data to and from an IC tag, and is a means for displaying data read from the IC tag and data written to the IC tag. As shown in FIGS. 3 and 4, the display panel 20 includes substrates 21 and 22 bonded together via a frame-shaped peripheral sealing material 24 (not shown in FIG. 3) so as to face each other. The substrates 21 and 22 are light-transmitting plate members made of glass or plastic. As shown in FIG. 3, in a region where the substrate 21 and the substrate 22 overlap each other (so-called display region), a plurality of pixels G are arranged in a matrix so as to correspond to the intersections of scanning lines and data lines (both not shown). Is arranged. Each pixel G includes a liquid crystal sandwiched between the substrate 21 and the substrate 22 and a pair of electrodes for applying a voltage to the liquid crystal.

  IC chips 42 (421, 422, 423, and 424) are mounted on a region (hereinafter referred to as “peripheral region”) that protrudes from the periphery of the substrate 22 in the surface S of the substrate (base material) 21. These IC chips 42 are bare chips. Among these, each of the IC chips 421 and 422 has a scanning line driving circuit that sequentially outputs scanning signals to the respective scanning lines, and the IC chip 423 outputs an image signal corresponding to the gradation to be displayed to each data. A data line driving circuit for outputting from the line to the pixel G; On the other hand, the IC chip 424 outputs various control signals such as a clock signal to each scanning line driving circuit and data line driving circuit in addition to the communication circuit and the storage circuit similar to the IC chip 41 of the first embodiment. A control circuit.

  On the surface S of the substrate 21, a plurality of wirings 63 for transmitting signals exchanged between the IC chips 42 are formed. As shown in FIG. 4, each IC chip 42 is mounted on the surface S of the substrate 21 with the bonding surface 401 formed with a plurality of bumps 402 facing the surface S (so-called COG (Chip On Glass) mounting). ) That is, in the state where the bonding surface 401 of each IC chip 42 is bonded to the surface S by the adhesive 511 of the anisotropic conductive film 51, the connection terminal 631 (see FIG. 5) formed at the end of each wiring 63 The bumps 402 of each IC chip 42 are electrically connected via the conductive particles 512 of the anisotropic conductive film 51. Further, a sealing material 53 for isolating the bonding surface 401 from the outside air is provided around each IC chip 42, and the sealing material 53 is bonded to the substrate 21.

  Further, an antenna coil 61 is disposed around the IC chip 424 when viewed from a direction perpendicular to the surface S of the substrate 21. Each end of the antenna coil 61 is connected to the communication circuit of the IC chip 424 via the connection terminal 633 of the wiring 63. The antenna coil 61 is arranged inside a sealing material 53 provided around the IC chip 424, as in the first embodiment. Therefore, also in this embodiment, the same effect as the first embodiment can be obtained.

<3. Manufacturing method>
Next, a process for manufacturing the electronic apparatus according to the embodiment of the invention will be described. In addition, although the manufacturing process of the electronic device which concerns on the said 2nd Embodiment is illustrated here, the electronic device 10 which concerns on 1st Embodiment is manufactured by the same process. In the following, the description will be focused on the vicinity of the portion where the IC chip 424 is arranged.

  First, as shown in FIG. 5, a sheet-like anisotropic conductive film 51 is disposed in a region of the surface S of the substrate 21 where the IC chip 424 is to be mounted. The anisotropic conductive film 51 is disposed so as to overlap the connection terminal 631 of the wiring 63 formed on the surface S of the substrate 21. Next, as shown in FIG. 6, the IC chip 424 is mounted on the substrate 21. That is, first, the IC chip 424 is arranged and the position thereof is adjusted so that the bonding surface 401 on which the bump 402 is formed faces the anisotropic conductive film 51, and second, the anisotropic conductive film 51 is adjusted. The IC chip 424 is pressed and fixed to the substrate 21 side while heating.

  Subsequently, as shown in FIG. 7, the antenna coil 61 is disposed so as to surround the IC chip 424 when viewed from the direction perpendicular to the surface S. At this time, the antenna coil 61 is held in a posture in which each end contacts the connection terminal 633 on the substrate 21 and does not contact the other wiring 63. Thereafter, as shown in FIG. 8, a sealing material 53 is deposited so as to cover the periphery of the IC chip 424. By this step, the antenna coil 61 is fixed inside the sealing material 53 while maintaining the posture in which each end is in contact with the connection terminal 633, and the IC chip 424 and the connection terminal are sealed. Thereafter, the resin sealing material 53 is cured. Through the above steps, the display panel 20 of the second embodiment is obtained.

<4. Modification>
Various modifications are made to the above embodiment. Specific modes of deformation are as follows. The following aspects may be appropriately combined.

(1) In each of the above embodiments, the configuration in which the antenna coil 61 is disposed so as to surround the IC chip 41 or 424 including the communication circuit is illustrated. However, the antenna coil 61 is disposed around other IC chips. A configured configuration may also be employed. For example, the antenna coil 61 may be arranged so as to surround the IC chip 421, 422, or 423 shown in FIG. In this configuration, the wiring 63 is formed so as to extend from the end of the antenna coil 61 to the IC chip 424 provided with a communication circuit. However, when a communication circuit is mounted on the IC chip 421, 422, or 423 together with a driving circuit (scanning line driving circuit or data line driving circuit), the antenna coil 61 is used as the IC chip 421, 422, or 423. Connected to. Further, in each of the above embodiments, the configuration in which the antenna coil 61 is connected to the IC chip 41 or 424 via the wiring 63 is illustrated, but the IC coil 41 or 424 is directly connected without the antenna coil 61 via the wiring 63. A configuration connected to the bump 402 (more specifically, the bump 402) may be employed. Further, each IC chip may have not only a single function but also a plurality of functions such as communication and pixel driving.

(2) In the second embodiment, the configuration in which the separate sealing material 53 is formed for each of the plurality of IC chips 42 is exemplified. A formed configuration may also be employed. For example, the sealing material 53 may be formed so as to cover the entire peripheral region shown in FIG. In each of the above embodiments, the configuration in which the sealing material 53 is formed so that the upper surface (surface opposite to the bonding surface 401) of each IC chip 41 or 42 is exposed is exemplified. It is good also as a structure by which the sealing material 53 was formed so that 41 or 42 might be covered completely also including an upper surface. Also, a plurality of antenna coils can be provided as necessary. For example, transmission, reception, power supply, etc. may be used properly.

(3) In each of the above-described embodiments, the case where the present invention is applied to an IC tag and a reader / writer has been illustrated. However, other electronic devices 10 (for example, mobile phones and PDAs (Personal The present invention can also be applied to communication terminals) such as Digital Assistants). Moreover, in the said 2nd Embodiment, although the display panel 20 using a liquid crystal was illustrated, it is unquestioned whether the structure of a display panel is. For example, OLED (Organic) such as organic EL (Electroluminescent) element
The present invention can be applied to various display panels such as a light emitting diode) device, a plasma display device, and a display panel using an electrophoretic device.

It is a top view which shows the structure of the board | substrate with which IC chip is arrange | positioned among the electronic devices which concern on 1st Embodiment of this invention. It is sectional drawing seen from the II-II line | wire in FIG. It is a top view which shows the structure of a display panel among the electronic devices which concern on 2nd Embodiment of this invention. It is sectional drawing seen from the IV-IV line in FIG. It is a top view which shows the process by which an anisotropic conductive film is arrange | positioned on the surface of a board | substrate. It is a top view which shows the process by which an IC chip is arrange | positioned on the surface of a board | substrate. It is a top view which shows the process by which an antenna coil is arrange | positioned on the surface of a board | substrate. It is a top view which shows the process in which a sealing material is formed on the surface of a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electronic device, 20 ... Display panel, G ... Pixel, 11, 21, 22 ... Substrate, 41, 42 (421, 422, 423, 424) ... IC chip, 401 ... Mounting surface, 402 ...... Bump, 51... Anisotropic conductive film, 53... Sealing material, 61... Antenna coil, 63.

Claims (4)

A substrate;
An IC chip disposed on the substrate;
A sealing material bonded to the base material and sealing the IC chip;
An electronic device comprising: an antenna coil disposed inside the sealing material in a form surrounding the IC chip. The antenna coil is electrically connected to the IC chip,
The electronic apparatus according to claim 1, wherein the IC chip includes a communication circuit that controls transmission / reception of data via the antenna coil. A substrate on which a plurality of pixels are arranged;
A first IC chip having a drive circuit for supplying a drive signal to each pixel and disposed on the substrate;
A second IC chip having a communication circuit for controlling transmission and reception of data and disposed on the substrate;
A sealing material bonded to the substrate and sealing each IC chip;
An electronic device comprising: an antenna coil disposed inside the sealing material so as to surround the second IC chip and electrically connected to the second IC chip. A chip placement step of placing an IC chip on a substrate;
An antenna placement step of placing an antenna coil so as to surround the IC chip;
A sealing step of depositing a sealing material on the base material to enclose the antenna coil with the sealing material and sealing the IC chip.

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