JP2008053337A - Substrate for communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication substrate utilizing 2D-DST technology for preventing reflection and leakage of electromagnetic waves at an end surface of a substrate. <P>SOLUTION: The substrate for communication 20 includes a first conductor layer, a second conductor layer, a plurality of communication elements electrically connected to both layers, and a signal-transmitting layer 23 arranged in between both layers. The plurality of communication elements have the function of transmitting and receiving radio signals, both layers are formed respectively with a sheet member and have external circumference protruded in the predetermined size from the signal transmitting layer 23, and the first conductor layer and the second conductor layer are arranged adjacent to each other and form a region of a substantially wedge shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication substrate capable of transmitting signals by relaying signals using a plurality of communication elements.

  A communication device that transmits a signal by relaying the signal using a plurality of elements is disclosed in Patent Document 1.

  The communication device described in Patent Literature 1 includes a first signal layer and a second signal layer, a communication element that is electromagnetically connected to these layers, and a dielectric layer disposed between these layers. The communication element generates an electromagnetic field electrically or optically between the first signal layer and the second signal layer, and an adjacent communication element observes a signal by the change of the electromagnetic field. In the communication device, a signal can be transmitted by a plurality of elements relaying a signal without forming individual wiring.

  In addition, a technique including a conductive sheet and a plurality of communication modules that are scattered on the conductive sheet and transmit signals to adjacent communication modules using the conductive sheet is a two-dimensional diffusion signal transmission (2D -DST) known as technology (see Patent Document 2).

JP 2004-242220 A JP-A-2005-245937

  In the communication apparatus as described in Patent Document 1 using the 2D-DST technology, the electromagnetic wave transmitted from the communication element is not only the adjacent communication element but also the end of the dielectric layer, that is, the end of the communication apparatus. It may also occur when reaching the part.

  If the end of the communication device is open and the dielectric layer is exposed to the outside of the device, there is a concern about leakage of electromagnetic waves. Further, even if the end of the communication device is blocked by some means, the electromagnetic wave is reflected this time. When the electromagnetic wave is reflected at the end of the dielectric layer, the communication element may detect an unnecessary electromagnetic wave, and there is a concern that the reception performance of the communication element is deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent reflection and leakage of electromagnetic waves on a substrate end face in a communication substrate using 2D-DST technology.

  In order to solve the above problems, in the present invention, a first conductive layer and a second conductive layer, a plurality of communication elements electrically connected to the both layers, and signal transmission disposed between the two layers A plurality of communication elements having a function of transmitting and receiving radio signals, each of the two layers being formed of a sheet-like member, and having an outer peripheral portion protruding a predetermined amount from the signal transmission layer And the outer peripheral portions of the two layers are disposed close to each other so that a substantially wedge-shaped region is formed by the first conductive layer and the second conductive layer. Providing a substrate.

  Therefore, in the present invention, the two conductive layers sandwiching the signal transmission layer for transmitting electromagnetic waves (wireless signals) form a substantially wedge-shaped region near the outer periphery. That is, because the conductive layer forms a radio wave absorber having a wedge-shaped region around the substrate, electromagnetic waves transmitted from the communication element are attenuated, and as a result, reflection and leakage are prevented.

  In the communication substrate according to the present invention, at least one notch is formed in the outer periphery of the first conductive layer, and the outer periphery of the first conductive layer is formed in the outer periphery of the second conductive layer. The notch is formed so as to correspond to the position where the notch of the part is not formed, and the outer periphery of the first conductive layer and the outer periphery of the second conductive layer are not in contact with each other. The substantially wedge-shaped region is formed by intersecting using the notch. Therefore, in the present invention, the two conductive layers sandwiching the signal transmission layer for transmitting electromagnetic waves (wireless signals) form macroscopic wedge-shaped regions by alternately combining the notch portions in the vicinity of the outer peripheral portion. . A macroscopic wedge-shaped region can be formed without contact between the two conductive layers. That is, because the conductive layer forms a radio wave absorber having a wedge-shaped region around the substrate, electromagnetic waves transmitted from the communication element are attenuated, and as a result, reflection and leakage are prevented.

  In the communication substrate according to the present invention, the first conductive layer and the second conductive layer may be further disposed at an outer edge portion than a position where the outer peripheral portion of the first conductive layer and the outer peripheral portion of the second conductive layer intersect. An insulating member is interposed between the conductive layers. Moreover, you may provide the insulation protection member which covers the outer peripheral part of the said 1st conductive layer and the outer peripheral part of the said 2nd conductive layer at least.

  Alternatively, surfaces of the first conductive layer and the second conductive layer opposite to the signal transmission layer are respectively covered with an insulating layer, and an outer peripheral portion of the first conductive layer and an outer peripheral portion of the second conductive layer The first conductive layer is in contact with the insulating layer covering the second conductive layer at a further outer edge portion than the position where the outer peripheral portion of the first conductive layer and the outer peripheral portion of the second conductive layer intersect. Thus, the second conductive layer may be folded back so as to be in contact with the insulating layer covering the first conductive layer.

  Further, the width of the shape of the part of the outer peripheral part of the first conductive layer and the outer peripheral part of the second conductive layer that is not cut out may be narrower toward the outer peripheral direction. The signal transmission layer is a dielectric.

  Therefore, in the present invention, in the communication substrate using the 2D-DST technology, it is possible to prevent reflection and leakage of electromagnetic waves on the substrate end surface.

  Hereinafter, a communication substrate according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of a communication board 1. The communication substrate 1 includes a communication chip 10 and a substrate 20. A control device 30 is connected to the communication board 1. The control device 30 has a function of controlling the entire communication board 1. The communication substrate 1 is used, for example, for clothing of a subject of a capsule endoscope (see Patent Document 1). And the communication chip 10 is arrange | positioned so that it may protrude from the board | substrate 20 so that the radio | wireless image signal from a capsule endoscope can be received. In the embodiment of the present invention, the communication substrate 1 and the control device 30 will be described mainly as being used for clothing of the subject of the capsule endoscope, but the embodiment is not limited to these embodiments. The feature of the communication substrate 1 that transmits signals via the communication chip 10 without a wired circuit can be used as various information transmission means.

  The communication chips 10 are scattered on the substrate 20, and each communication chip 10 can communicate with another communication chip 10 or the control device 30. In the embodiment of the present invention, all communication chips 10 are configured to be able to communicate with the control device 30. As will be described later, the communication chip 10 performs communication using a radio signal that can be transmitted only within the substrate 20. The communicable range of the communication chip 10 is a two-dimensional area that extends in a circle in the substrate 20. Therefore, the radio signal transmitted by the communication chip 10 can reach not only the other communication chip 10 and the communication control device 30 but also the end of the substrate 20.

  FIG. 2 is a functional block diagram of the communication chip 10. For example, when the communication substrate 1 is used for clothing of a subject of a capsule endoscope, each communication chip 10 is provided with an antenna for receiving a radio image signal from the capsule endoscope. The image signal is transmitted from the communication chip 10 that has received the wireless image signal to the control device 30. For example, the communication chip 10 can digitize an image signal and transmit it as a packet.

  The communication chip 10 performs communication with the control unit 11 that controls the entire communication chip 10, the memory 12 that stores various data of the communication chip 10, and the other communication chip 10 or the control device 30. The communication unit 13 includes an antenna 14 that transmits and receives radio waves having a predetermined frequency. For example, the communication chip 10 can receive a wireless image signal from the capsule endoscope via the antenna 14. Further, the communication chip 10 can transmit and receive a radio signal by the communication unit 13.

  FIG. 3 is a functional block diagram of the control device 30. The control device 30 includes a control unit 31 that controls the function of the control unit 30, a power source 32 that functions as a power source for the control device 30 and the communication substrate 1, a communication unit 33 that communicates with the communication chip 10, and various control devices. A memory 34 for storing programs and acquired information, a signal processing unit 35 for performing processing so that the acquired image signal can be displayed on a monitor, and connection to an external device and output of information to the external device And an interface unit 36. Information such as image signals acquired in each communication chip 10 is collected under the control of the control device 30.

  FIG. 4 is a partial cross-sectional view of the communication substrate 1 and shows the vicinity of the end portion. The substrate 20 includes a first insulating layer 21, a power supply layer 22, a dielectric layer 23, a ground layer 24, a second insulating layer 25, and a third insulating layer 26. Each layer included in the substrate 20 has flexibility. The dielectric layer 23 and the third insulating layer 26 may have some rigidity.

  The first insulating layer 21 and the second insulating layer are sheet-like members having insulation properties. The power supply layer 22 and the ground layer 24 are conductive sheet-like members. Alternatively, it is a member such as a conductive mesh. The dielectric layer 23 is sandwiched between the power supply layer 22 and the ground layer 24. In the embodiment of the present invention, the dielectric constant of the dielectric layer 23 is set so that the radio signal (electromagnetic wave) output from the communication chip 10 in the communication substrate 1 can reach the control device 30. .

  The power supply layer 22 and the first insulating layer 21 are provided with openings for arranging the communication chip 10. That is, the communication chip 10 is disposed so as to penetrate the power supply layer 22 and the first insulating layer 21 and to be in contact with the dielectric layer 23. The communication chip 10 includes an electrode 15 and an electrode 16, and the electrode 15 is connected to the power supply layer 22 and the electrode 16 is connected to the ground layer 24. The communication chip 10 receives power supply from the control device 30 via the power supply layer 22 and the ground layer 24. The communication unit 13 of the communication chip 10 is provided at a position in contact with the dielectric layer 23, and can transmit a radio signal to the dielectric layer 23 and receive a radio signal from the dielectric layer 23.

  A portion of the substrate 20 on the outer edge side of the dielectric layer 23 is referred to as an outer peripheral portion 20a. FIG. 4 shows only one end of the outer peripheral portion 20a. For example, if the substrate 20 has a quadrangular shape, there are four outer peripheral portions 20a.

  Hereinafter, for convenience of explanation, the first insulating layer 21 and the power supply layer 22 are collectively referred to as an upper layer 122, and the ground layer 24 and the second insulating layer 25 are collectively referred to as a lower layer 124. .

  A layer crossing portion 20b is formed on the outer peripheral portion 20a. The layer intersecting portion 20b refers to a portion where the upper layer 122 and the lower layer 124 intersect when viewed from the direction perpendicular to the cross section of FIG. The first insulating layer 21 and the second insulating layer 25 are disposed on the inner side in the thickness direction of the substrate 20 than the power supply layer 22 and the ground layer 24, respectively, on the outer peripheral side of the substrate 20 with respect to the layer intersection 20a. A third insulating layer 26 is provided between the first insulating layer 21 and the second insulating layer 25 for the purpose of fixing the first insulating layer 21 and the second insulating layer 25. The third insulating layer 26 has a shape extending along the outer peripheral edge of the substrate 20. Further, the third insulating layer 26 can maintain the shapes of the upper layer 122 and the lower layer 124 at the layer intersection portion 20b.

  FIG. 5 is a partial cross-sectional perspective view of the substrate 20, and FIG. 6 is a diagram showing the shapes of the upper layer 122 and the lower layer 124. In both figures, the communication chip 10 is not shown. Further, FIG. 5 shows the upper layer 122, the lower layer 124, and the dielectric layer 23 separately from each other. However, for convenience of explanation, they are shown as such, and in actuality they are in contact with each other. ing.

  In the outer peripheral portion 20a, the upper layer 122 and the lower layer 124 have a shape cut out in a comb shape. The upper layer has a convex part 122a and a concave part 122b. The lower layer has a convex part 124a and a concave part 124b. In the outer peripheral portion 20 a, the convex portion 122 a of the upper layer 122 is formed to correspond to the concave portion 124 b of the lower layer 124, and the concave portion 122 b of the upper layer 122 is formed to correspond to the convex portion 124 a of the lower layer 124. Therefore, in the layer intersection part 20b, as shown in FIG. 5, the upper layer 122 and the lower layer 124 can be alternately crossed and arranged.

  In the upper layer 122 and the lower layer 124, the width of the convex portion is formed to be slightly narrower than the width of the concave portion of the opposing layer. That is, the width of the convex portion 122a of the upper layer 122 is narrower than the width of the concave portion 124b of the lower layer 124, and the width of the convex portion 124a of the lower layer 124 is narrower than the width of the concave portion 122b of the upper layer 122. By doing so, the power supply layer 22 and the ground layer 24 do not come into contact with each other at the layer intersection portion 20b, and a short circuit can be prevented.

  Further, in the convex portion 122a of the upper layer 122, the power supply layer 22 may be configured so that the width of the power supply layer 22 is slightly narrower than the width of the first insulating layer 21, and the power supply layer 22 is disposed inside. Similarly, in the convex portion 124a of the lower layer 124, the width of the ground layer 24 may be slightly narrower than the width of the second insulating layer 25, and the ground layer 24 may be arranged inside. By doing so, even if the convex portion 122a of the upper layer 122 and the convex portion 124a of the lower layer 124 are in contact with each other at the layer intersecting portion 20b, the power supply layer 22 and the ground layer 24 are not in contact with each other, thereby preventing a short circuit. .

  FIG. 7 is a diagram for explaining the effect on the electromagnetic wave in the communication substrate 1. The communication substrate 1 utilizes the principle of a radio wave absorber used in an anechoic chamber or the like. The radio wave absorber generally has a pyramid shape or a wedge shape. For example, in an anechoic chamber in which a plurality of wedge-shaped wave absorbers are arranged, radio waves can be gradually absorbed by a wedge-shaped region formed between the wedge-shaped wave absorbers. In general, a radio wave absorber is formed by mixing or impregnating an organic foam with a conductive material such as carbon.

  In the communication substrate 1, the electromagnetic wave E is output from the communication unit 13 of the communication chip 10. The electromagnetic wave E propagates through the dielectric layer 23 in a plane. In the communication substrate 1, the layer-intersection 20 b has a wedge-shaped region formed by the upper layer 122 and the lower layer 124 when viewed macroscopically. That is, for example, in the embodiment of the present invention, since the radio signal by the communication chip 10 uses the 2.4 GHz band, its wavelength is about 125 mm. Moreover, when using the communication board | substrate 1 as a test subject's clothing, the size of the board | substrate 10 will be about 600 mm x 300 mm. Therefore, if the convex portion 122a (124a) having a width of several mm to several cm smaller than the wavelength used is formed, the layer crossing portion 20b can be regarded as a wedge-shaped region macroscopically.

  Furthermore, since the power supply layer 22 and the ground layer 24 are made of a conductive material, the electromagnetic wave E can be absorbed by the wedge-shaped region formed at the layer intersection 20b. Therefore, if the layer crossing portion 20b is formed around the communication substrate 1, leakage and reflection of the electromagnetic wave E can be prevented.

  FIG. 8 is a diagram showing a second embodiment of the communication board of the present invention. In FIG. 8, the same members as those in the communication substrate 1 shown in FIGS. 4 to 7 are denoted by the same reference numerals, and redundant description is omitted.

  The communication substrate 201 has a configuration in which an insulation protection member 202 is provided on the communication substrate 1. The insulation protection member 202 extends along the outer edge of the substrate 20 and has a shape that completely covers the outer peripheral portion 20a. The insulation protection member 202 is a member molded from resin or the like, for example, and may have a certain degree of rigidity. In the communication substrate 201, the power supply layer 22 and the ground layer 24 are not exposed to the outside of the communication substrate 201 by using the insulating protection member 202. Moreover, the shape of the upper layer 122 and the lower layer 124 of the layer crossing part 20b can be maintained.

  FIG. 9 is a diagram showing a third embodiment of the communication board of the present invention. Also in FIG. 9, like FIG. 8, about the same member as the communication board 1 shown in FIGS. 4-7, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  The communication substrate 301 has a configuration in which the third insulating layer 26 is omitted from the communication substrate 1. That is, at the layer intersection portion 20b, the convex portions 122a and the convex portions 124a of the upper layer 122 and the lower layer 124 are configured to be folded 180 degrees with a predetermined curvature. The vicinity of the tip of the protrusion 122a is attached to the surface of the lower layer 124, and the vicinity of the tip of the protrusion 124a is attached to the surface of the upper layer 122. Note that, at the layer intersection portion 20b, the convex portion 122a and the convex portion 124a are folded so that the wedge-shaped region formed by the upper layer 122 and the lower layer 124 is not lost. With such a configuration, the power supply layer 22 and the ground layer 24 are not disposed on the outermost surface of the communication substrate 301 but are covered with the first insulating layer 21 and the second insulating layer 25.

  10 and 11 are views showing a fourth embodiment of the communication board according to the present invention. FIG. 10 is a partial cross-sectional perspective view showing a part of the communication board 401. The same members as those in the communication board 1 shown in FIGS.

  The communication substrate 401 includes a substrate 420 and a communication chip 10 (not shown). The substrate 420 includes an upper layer 422, a lower layer 424, the dielectric layer 23, and the third insulating layer 26. The upper layer 422 is obtained by changing only the shape of the outer peripheral portion 20a of the upper layer 122. Similarly, the lower layer 424 is also obtained by changing only the shape of the outer peripheral portion 20a of the lower layer 124.

  FIG. 11 is a diagram showing the shapes of the upper layer 422 and the lower layer 424, as in FIG. The upper layer 422 has a triangular convex part 422a and a concave part 422b at the end. The lower layer 424 also has a triangular convex portion 424a and a concave portion 424b at the end. In the communication substrate 401, the triangular protrusions 422 a of the upper layer 422 are formed to correspond to the recesses 424 b of the lower layer 424, and the recesses 422 b of the upper layer 422 are formed to correspond to the triangular protrusions 424 a of the lower layer 424. Therefore, in the layer intersection portion 420b of the communication substrate 401, the upper layer 422 and the lower layer 424 can be alternately crossed as shown in FIG. With such a configuration, the triangular convex portions 422a and 424b do not come into contact with each other at the layer intersection portion 420b.

  Note that the configuration of the communication substrate 401 can also be adopted in the above-described communication substrates 201 and 301. That is, the convex portion 122a and the convex portion 124a may be replaced with the triangular convex portion 422a and the triangular convex portion 424a.

  In the communication substrate 401, the insulation protection member 202 employed in the communication substrate 201 can be implemented, and the convex portion employed in the communication substrate 301 can be folded back.

  In a communication substrate using 2D-DST technology, a dielectric layer is sandwiched between two conductive layers from above and below, and electromagnetic waves are propagated in the dielectric layer. The transmission band of electromagnetic waves by the communication element is mainly 2.4 GHz. If the end face is exposed at the periphery of the communication substrate, electromagnetic waves leak. On the other hand, when electromagnetic waves are reflected on the end face of the substrate, there is a concern about signal degradation due to multipath or the like.

  Moreover, since the 2.4 GHz band is used, the wavelength is about 125 mm. On the other hand, the size of the communication board assumed to be worn by the human body is about 600 mm × 300 mm, and the board size is likely to be ½λ × N (integer). Therefore, the adverse effect when electromagnetic waves are reflected on the outer periphery of the substrate is very large. In the communication substrate according to the present invention, reflection of electromagnetic waves on the end face of the substrate can be prevented.

It is the schematic of the board | substrate 1 for communication of embodiment of this invention. 2 is a functional block diagram of a communication chip 10. FIG. 3 is a functional block diagram of a control device 30. FIG. 1 is a cross-sectional view of a communication substrate 1. FIG. 2 is a partial cross-sectional perspective view of a substrate 20. FIG. It is a figure which shows the shape of the upper layer 122 and the lower layer 124. FIG. It is a figure which shows attenuation | damping (absorption) of electromagnetic waves typically. It is a figure which shows 2nd embodiment of the board | substrate for communication of this invention. It is a figure which shows 3rd embodiment of the board | substrate for communication of this invention. It is a figure which shows 4th embodiment of the board | substrate for communication of this invention. It is a figure which shows 4th embodiment of the board | substrate for communication of this invention.

Explanation of symbols

1, 201, 301, 401 Communication substrate 10 Communication chip 20 Substrate 21 First insulating layer 22 Power supply layer 23 Dielectric layer 24 Ground layer 25 Second insulating layer 26 Third insulating layer 30 Controller 202 Insulating protective member

Claims (7)

A first conductive layer and a second conductive layer;
A plurality of communication elements electrically connected to both layers;
A signal transmission layer disposed between the two layers,
The plurality of communication elements have a function of transmitting and receiving radio signals,
Each of the two layers is formed of a sheet-like member, and has an outer peripheral portion protruding a predetermined amount from the signal transmission layer,
The communication substrate according to claim 1, wherein the outer peripheral portions of the two layers are arranged close to each other so that a substantially wedge-shaped region is formed by the first conductive layer and the second conductive layer. A position where at least one notch portion is formed in the outer peripheral portion of the first conductive layer, and a notch portion of the outer peripheral portion of the first conductive layer is not formed in the outer peripheral portion of the second conductive layer. The notch is formed to correspond to
The substantially wedge-shaped region is formed by intersecting using the notch so that the outer periphery of the first conductive layer and the outer periphery of the second conductive layer do not contact each other. The communication board according to claim 1, characterized in that:   An insulating member is interposed between the first conductive layer and the second conductive layer at a further outer edge portion than the position where the outer peripheral portion of the first conductive layer and the outer peripheral portion of the second conductive layer intersect. The communication board according to claim 1, wherein the communication board is inserted.   4. The communication substrate according to claim 1, further comprising an insulation protection member that covers at least an outer peripheral portion of the first conductive layer and an outer peripheral portion of the second conductive layer. 5. The surfaces of the first conductive layer and the second conductive layer opposite to the signal transmission layer are each covered with an insulating layer,
The outer peripheral portion of the first conductive layer and the outer peripheral portion of the second conductive layer are further at the outer edge portion than the position where the outer peripheral portion of the first conductive layer and the outer peripheral portion of the second conductive layer intersect. The first conductive layer is folded so as to contact the insulating layer covering the second conductive layer, and the second conductive layer is folded so as to contact the insulating layer covering the first conductive layer. The communication board according to claim 1, wherein the communication board is provided.   The width of the shape of the part of the outer peripheral part of the first conductive layer and the outer peripheral part of the second conductive layer that is not cut out becomes narrower toward the outer peripheral direction. The communication board according to any one of the above.   The communication substrate according to claim 1, wherein the signal transmission layer is a dielectric.

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