JP2005167996A - Communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device in which the influence of high-frequency noise produced from active surfaces of ICs is reduced and of which the sensitivity is improved by appropriately arranging the ICs which are noise sources. <P>SOLUTION: A high-frequency analog IC (91A) and a digital IC (92A) for processing signals, both of which generate high-frequency noise, are mounted on the back (712) of a circuit board (71) with the faces of the ICs down. Namely, the active surfaces (910A and 920A) of the ICs (91A and 92A) do not face to a loop antenna (4) provided integrally with an arm band on the back side of the circuit board (71), but to a liquid crystal panel provided on the front side of the main body of the communication device. Consequently, even when high-frequency noise is produced from the active surfaces of the ICs (91A and 92A), the activity of the communication device is high because noise hardly reaches the loop antenna (4). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a communication device such as a receiver or a transmitter. More specifically, the present invention relates to a technique for effectively reducing the influence of high-frequency noise generated from an integrated circuit (hereinafter referred to as IC) in a communication device on an antenna body.

  As portable transmitters or receivers, wristwatches with FM radios, wristwatch-type individual selection call receivers, and the like are known. In these wristwatch-type devices, by incorporating a conductive plate or film into the arm band for mounting the device body on the arm, when the arm band is mounted on the arm, the above-mentioned plate or film etc. Is configured.

  In such a communication apparatus, as schematically shown in FIG. 9B, the apparatus main body is driven by a high-frequency analog IC 93B for performing transmission or reception and a high-frequency drive signal such as several MHz. A circuit board 73 on which a digital IC 94B for signal processing is mounted is incorporated. These ICs (both are shown as A / B-IC) are on the back side of the circuit board 73 (on the side where the whole or most of the loop antenna 4 is located). 732 is wire-bonded.

  A display digital IC 95B (shown as C-IC) driven by a drive signal of several tens of kHz is provided on the surface side of the circuit board 73 (the liquid crystal display panel 6 side). It is mounted on the surface portion 721 by wire bonding.

  However, in the wrist-worn communication device, the inventor of the present application has studied various influences of high-frequency noise. As in the past, the high-frequency analog IC 93B or the digital IC 94B for signal processing is wire-bonded to the back surface portion 732 of the circuit board 73. Then, the new knowledge that sensitivity was low was acquired. That is, although the high-frequency analog IC 93B or the active surfaces 930B and 940B of the digital IC 94B for signal processing (meaning surfaces on which terminals are exposed, wiring surfaces, and element surfaces) generate high-frequency noise. However, if the high-frequency analog IC 93B or the digital IC 94B for signal processing is arranged so that the active surfaces 930B and 940B face the loop antenna 4 as in the prior art, the loop antenna 4 is easily affected by the high-frequency noise. Because.

  In view of the above problems, an object of the present invention is to reduce the influence of high-frequency noise generated from the active surface of an IC by optimizing the arrangement of the IC that is a noise generation source, and to provide a communication device with high sensitivity. It is to provide.

  In order to solve the above-mentioned problems, in the present invention, a communication apparatus having a substrate on which an integrated circuit that generates high-frequency noise is mounted, and an antenna body that is located entirely or mostly on one substrate surface side of the substrate. The integrated circuit is mounted on the substrate such that an active surface faces in a direction opposite to a direction in which the whole or most of the antenna body is located with respect to the substrate.

  In the communication device according to the present invention, the integrated circuit that generates high-frequency noise has an active surface facing a direction opposite to a direction in which the whole or most of the antenna body is located with respect to the substrate. Even if high frequency noise is emitted from the active surface, this high frequency noise is difficult to reach the antenna body. Therefore, the sensitivity of the communication device can be improved.

  When such a communication device is configured as an arm-mounted type, for example, an apparatus main body in which the display surface side is the front surface side, and the apparatus main body is used as an arm extending from the apparatus main body to the back surface side. An arm band for mounting is provided, the antenna body is configured on the arm band, and the substrate is disposed on the back surface side of the display surface in the apparatus main body.

  In the present invention, the integrated circuit that generates the high-frequency noise is, for example, a high-frequency analog integrated circuit having at least one of a transmission function and a reception function, or for signal processing driven by a high-frequency drive signal. Digital integrated circuit, or an integrated circuit such as a CPU.

  In the present invention, in order to mount an integrated circuit on a substrate so that the active surface faces in the direction opposite to the direction in which the whole or most of the antenna body is located with respect to the substrate, for example, the entire antenna body on the substrate Alternatively, the integrated circuit is face-down bonded to the substrate surface on the side where the majority is located.

  In addition, the integrated circuit is wire-bonded to the substrate surface opposite to the side where the whole or most of the antenna body is located on the substrate, thereby the side opposite to the direction where the whole or most of the antenna body is located with respect to the substrate. The active surface of the integrated circuit may be oriented in the direction of.

  In the present invention, face-down bonding is a method in which a surface electrode or wiring lead attached in advance to a semiconductor chip for an integrated circuit and a wiring electrode formed on a substrate are bonded to each other so that the surfaces face each other. Means all the methods of electrical connection, including flip chip bonding. BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described based on the drawings.

  In the communication device according to the present invention, the active surface of the integrated circuit that generates high-frequency noise faces in the direction opposite to the direction in which the whole or most of the antenna body is located with respect to the circuit board. That is, in an integrated circuit that generates high frequency noise, the active surface does not face the antenna body. Therefore, even if the integrated circuit emits high frequency noise from the active surface, this high frequency noise is difficult to reach the antenna body, so that a highly sensitive communication device can be configured.

(Example 1)
FIG. 1 is an explanatory diagram showing a configuration of an arm-mounted communication device to which the present invention is applied. In FIG. 1, an arm-mounted communication device 1 is composed of a device body 2 having a liquid crystal display panel 6 (display surface) disposed on the surface side and a pair of arm bands 4R and 4L. Each of the arm bands 4R and 4L has a band base end attached to both ends of the apparatus main body, and these bands can be connected to each other by a buckle 41 at each end portion.

  The arm bands 4R and 4L have conductor plates installed therein, and are attached to the user's wrist, and when the end portions of the arm bands 4R and 4L are joined to each other, the loop antenna 4 (antenna body) is attached. It is configured.

  The apparatus main body 2 includes a front surface side casing 3 a and a back cover 3 b fixed to the back side of the casing 3 a on the back side of the apparatus main body 2. A circuit assembly 5 is built in the apparatus main body 2 constituted by the casing 3a and the back cover 3b.

  2A and 2B show the front surface and the back surface of the circuit assembly 5, respectively. FIG. 3A is an explanatory diagram schematically showing a cross section taken along line IV-IV ′ in FIG. 2 of the circuit assembly 5.

  In these drawings, the circuit assembly 5 has a structure in which main components are stacked in the thickness direction inside the apparatus main body 2. That is, in the circuit assembly 5, the liquid crystal display panel 6, the circuit board 71, and the circuit driving battery 8 are arranged in the thickness direction.

  Each inner end of the loop antenna 4 is electrically and mechanically coupled to the terminal portion of the circuit board 71. These terminal portions are connected to the digital IC 90A. The loop antenna 4 is held by the arm bands 4R and 4L and extends to the back side of the circuit board 71.

  The loop antenna 4 does not necessarily have to be directly fixed to the circuit board 71, and may be electrically connected to the terminal portion of the circuit board 71. The loop antenna 4 may be simply connected by pressure or connected by a lead wire or the like. May be. Various electronic components are mounted on the circuit board 71, and the liquid crystal display panel 6 among the front side (side where the liquid crystal display panel 6 is located) and the back side (side where the whole or most of the loop antenna 4 is located) is mounted. A digital IC 90A (shown as C-IC) for controlling the display operation in the liquid crystal display device 6 is adhered to the surface portion 711 facing the surface by a face-down bonding method such as flip chip bonding. Connection has been made.

  In addition, on the back surface side where the majority of the loop antenna 4 configured when the end bandage of the arm bands 4R and 4L attached to the wrist is coupled to the circuit board 71 is located on the back surface portion 712, A high-frequency analog IC 91A having transmission and reception functions and a digital IC 92A for signal processing are mounted. These ICs (both are shown as A / B-IC) are also face-down bonded to the circuit board 71. For this reason, the high-frequency analog IC 91A and the signal processing digital IC 92A both have the active surfaces 910A and 920A directed toward the circuit board 71 (the side on which the liquid crystal display panel 6 is located). It is not suitable for the direction where is located.

  Here, the digital IC 90A for liquid crystal display is driven by a drive signal having a relatively low frequency such as several tens of kHz, and does not generate high frequency noise. On the other hand, the high frequency analog IC 91 </ b> A generates high frequency noise as indicated by an arrow A in order to transmit and receive high frequency signals such as several tens to several hundreds MHz.

  In addition, the digital IC 92A for signal processing incorporates a digital circuit, a phase lock loop circuit, and the like that sample a received signal before analog / digital conversion, and is driven by a high-frequency drive signal such as several MHz. As shown by A, high frequency noise is generated.

  However, in this example, the high-frequency analog IC 91A that generates high-frequency noise and the digital IC 92A for signal processing both have the active surfaces 910A and 920A on the circuit board 71 side (the liquid crystal display panel 6) on the back side of the circuit board 71. Is not directed in the direction in which most of the loop antenna 4 is located, and therefore the influence of the high-frequency noise generated by the loop antenna 4 is difficult to reach the loop antenna 4. Therefore, the arm-mounted communication device 1 to which the present invention is applied has high sensitivity.

  In order to examine the noise reduction effect, the arrangement structure of this example shown in FIG. 3A and the back surface portion 712 of the circuit board 71 on the liquid crystal display panel 6 as shown in FIG. A digital IC 90 </ b> B (shown as C-IC) that controls the display operation is face-down bonded, and a high-frequency analog IC 91 </ b> B that is a source of high-frequency noise with respect to the surface portion 711 of the circuit board 71 and signal processing. The relative sensitivity at the time of reception was compared with the arrangement structure according to the comparative example in which the digital IC 92B for the face is bonded face down.

  First, in FIG. 4, the active surface 910 </ b> A, 920 </ b> A is attached to the liquid crystal display panel by performing face-down bonding of a high-frequency analog IC 91 </ b> A and a signal processing digital IC 92 </ b> A that are sources of high-frequency noise on the back surface 712 of the circuit board 71. In the wrist-worn communication device 1 of this example directed to the side 6, the result of measuring the sensitivity at the time of reception in the frequency region of 87.4 MHz to 108.2 MHz is indicated by a polygonal line L1A.

  Also, in FIG. 4, the active surfaces 910 </ b> B and 920 </ b> B are connected to the loop antenna 4 by face-down bonding a high-frequency analog IC 91 </ b> B and a signal processing digital IC 92 </ b> B that are high-frequency noise sources to the surface portion 711 of the circuit board 71. In the wrist-worn communication device according to the comparative example directed to the side, the result of measuring the sensitivity at the time of reception in the frequency region of 87.4 MHz to 108.2 MHz is indicated by a broken line L1B.

  The vertical axis in FIG. 4 represents relative sensitivity when the reference sensitivity level is 0 dB.

  As is clear from this figure, in the arrangement structure of this example, the high frequency noise radiated from the active surfaces 910A and 920A of the high frequency analog IC 91A and the signal processing digital IC 92A is shown by an arrow A in FIG. In contrast to the arrangement structure according to the comparative example, high-frequency noise is not radiated toward the loop antenna 4, whereas the high-frequency radiated from the active surfaces 910 </ b> B and 920 </ b> B of the high-frequency analog IC 9 </ b> IB and the signal processing digital IC 92 </ b> B is shown in FIG. As indicated by the arrow B, the high frequency noise is radiated toward the loop antenna 4. For this reason, the arrangement structure of this example has higher sensitivity at any frequency of 87.4 MHz to 108.2 MHz than the arrangement structure of the comparative example. That is, the sensitivity when using the arrangement structure of this example is −2.5 dB in terms of relative sensitivity to the reference sensitivity, whereas the sensitivity when using the arrangement structure of the comparative example is relative to the reference sensitivity. The sensitivity is -1.0 dB, and according to the arrangement structure of this example, the sensitivity is improved by 1.5 dB.

  In FIG. 5, in the arm-mounted communication device using the arrangement structure of this example, the sensitivity when the communication device is configured with the circuit boards 71 mounted with the ICs is represented by a broken line L3A. In contrast, when the communication device is configured by shielding the entire surface where the high-frequency analog IC 91A is disposed and arranging the circuit driving battery 8 so as to face the back surface side of the circuit board 71, the sensitivity is indicated by the broken line L4A. The sensitivity in the case where the communication device is configured by arranging the battery 8 for circuit drive so as to shield both sides of the circuit board 71 and to face the back side of the circuit board 71 is represented by a broken line L5A. A shield plate to which a driving potential is applied is arranged on the back side of the circuit board 71, and the circuit driving battery 8 and the back cover are arranged so as to face the back side of the circuit board 71, so that the communication device The sensitivity in case where the is represented by broken line L6A.

  FIG. 6 also shows the sensitivity when the communication device is configured with the circuit board 71 mounted with each IC in the arm-mounted communication device using the arrangement structure according to the comparative example represented by a broken line L3B. The sensitivity when the communication device is configured by arranging the battery 8 for circuit driving so as to shield the entire surface where the high frequency analog IC 91 </ b> B is disposed with respect to 71 and the back side of the circuit board 71 is arranged is a broken line. L4B represents the sensitivity when the communication device is configured by arranging the battery 8 for circuit driving so that both sides of the circuit board 71 are shielded on the entire surface and opposed to the back side of the circuit board 71, and is represented by a broken line L5B. A shield plate to which a driving potential is applied is arranged on the back side of the circuit board 71, and the circuit driving battery 8 and the back cover are arranged so as to face the back side of the circuit board 71. The sensitivity in case where the communication apparatus is represented in broken line L6B.

  The vertical axis in FIGS. 5 and 6 represents relative sensitivity when the reference sensitivity level is 0 dB.

  5 and 6, the sensitivity is improved as the shield is taken regardless of which arrangement structure is used, but the sensitivity obtained from the sensitivity characteristics shown in FIGS. 5 and 6 is shown in comparison with Table 1. Thus, under any condition, the sensitivity is higher when the arrangement structure according to the present invention is adopted.

  In Table 1, the arm-mounted communication device having the same structure and the same specifications is shown in parentheses, but the sensitivity measured with another sample is shown. Moreover, the numerical value in Table 1 is an average value of the measured value in each graph shown in FIG. 5 and FIG.

  Further, FIG. 7 shows the sensitivity in the case where the communication device is configured with the circuit board 71 mounted with each IC in the arm-mounted communication device using the arrangement structure of this example, using this other sample. The communication device is represented by a broken line L3A, and the circuit drive battery 8 is disposed so as to shield the entire surface of the circuit board 71 where the high-frequency analog IC 91A is disposed and to face the back side of the circuit board 71. The sensitivity in the case of the configuration is represented by a broken line L4A, and the communication device is configured by arranging the battery 8 for circuit driving so that both sides of the circuit board 71 are shielded on the entire surface and facing the back side of the circuit board 71. Is represented by a broken line L5A, a shield plate to which a driving potential is applied is arranged on the back side of the circuit board 71, and the circuit driving battery 8 and the circuit board 71 are opposed to the back side of the circuit board 71. The sensitivity in case where the communication device by placing the back cover is represented by broken line L6A.

  Further, FIG. 8 shows the sensitivity in the case where the communication device is configured with the circuit board 71 mounted with each IC in the arm-mounted communication device using the arrangement structure according to the comparative example using the other sample. Is represented by a polygonal line L3B, the circuit board 71 is arranged so that the side on which the high frequency analog IC 91B is arranged is shielded from the circuit board 71 and the circuit driving battery 8 is arranged so as to face the back side of the circuit board 71. The communication device is configured by arranging the circuit driving battery 8 so that both sides of the circuit board 71 are shielded on the entire surface and opposed to the back side of the circuit board 71. The sensitivity in the case is represented by a broken line L5B, a shield plate to which a driving potential is applied is arranged on the back side of the circuit board 71, and the circuit driving battery is opposed to the back side of the circuit board 71. And it is represented by the broken line L6B sensitivity in case where the arrangement and the communication device back cover.

  The vertical axis in FIGS. 7 and 8 represents the relative sensitivity when the reference sensitivity level is 0 dB.

  As a result, as can be seen from Table 1, FIG. 7, and FIG. 8, the effect that the sensitivity is improved by using the arrangement structure to which the present invention is applied can be reproducible even if the sample is changed. Confirmed.

(Example 2)
The arm-mounted communication device of this example is substantially the same as the arm-mounted communication device according to the first embodiment except that the IC is wire-bonded to the circuit board. This will be described with reference to FIGS.

  In FIG. 1, an arm-mounted communication device 1 is composed of a device body 2 having a liquid crystal display panel 6 (display surface) disposed on the surface side and a pair of arm bands 4R and 4L. Each of the arm bands 4R and 4L has a band base end attached to both ends of the apparatus main body, and these bands can be connected to each other by a buckle 41 at each end portion.

  The arm bands 4R and 4L have conductor plates installed therein, are attached to the user's wrist, and when the end portions of the arm bands 4R and 4L are joined to each other, the loop antenna 4 (antenna body) Is configured. A circuit assembly 5 is built in the apparatus body 2.

  2A and 2B show the front surface and the back surface of the circuit assembly 5, respectively. FIG. 9A is an explanatory view schematically showing a cross section taken along line IV-IV ′ in FIG. 2 of the circuit assembly 5.

  In these drawings, the circuit assembly 5 has a structure in which main components are stacked in the thickness direction inside the apparatus main body 2. That is, in the circuit assembly 5, the liquid crystal display panel 6, the first circuit board 72, the second circuit board 73 arranged on the back side of the circuit board, and the circuit driving battery 8 are arranged in the thickness direction. Is arranged. The second circuit board 73 has a digital IC 95 </ b> A (for controlling the display operation on the liquid crystal display device 6 on the back surface portion 732 on the back surface side (the side where the whole or most of the loop antenna 4 is located). C-IC) is wire bonded.

  In the first circuit board 72, various electronic components are mounted. On the surface side (side on which the liquid crystal display panel 6 is located), the surface portion 721 has transmission and reception functions. A high frequency analog IC 93A and a digital IC 94A for signal processing are mounted. These ICs (both are shown as A / B-IC) are wire-bonded to the first circuit board 72. For this reason, both the high frequency analog IC 93A and the signal processing digital IC 94A have the active surfaces 930A and 940A facing the liquid crystal display panel 6 and are not oriented in the direction in which the loop antenna 4 is located.

  Here, the digital IC 95A for liquid crystal display is driven by a drive signal having a relatively low frequency such as several tens of kHz, and does not generate high frequency noise. On the other hand, the high frequency analog IC 93 </ b> A generates high frequency noise as indicated by an arrow C in order to transmit and receive high frequency signals such as several tens to several hundreds MHz. Further, the digital IC 94A for signal processing incorporates a digital circuit for sampling a received signal before analog / digital conversion, a phase lock loop circuit, and the like, and is driven by a high frequency drive signal such as several MHz. As shown by C, high frequency noise is generated.

  However, in this example, the high frequency analog IC 93A that generates high frequency noise and the digital IC 94A for signal processing both have the active surfaces 930A and 940A on the liquid crystal display panel 6 side on the surface side of the first circuit board 72. Directed, not toward the loop antenna 4. For this reason, the influence of the high frequency noise which it emits cannot reach the loop antenna 4 easily. Therefore, the arm-mounted communication device 1 of this example has high sensitivity.

  In order to examine such a noise reduction effect, the arrangement structure of this example shown in FIG. 9A and the surface portion 721 of the first circuit board 72 as shown in FIG. A digital IC 95B that controls display operation on the display panel 6 is wire-bonded, and a high-frequency analog IC 93B that is a source of high-frequency noise and a digital IC 94B for signal processing with respect to the back surface portion 732 of the second circuit board 73. The relative sensitivity at the time of reception was compared with the conventional arrangement structure in which the wire bonding is performed.

  As a result, the active surface 930A, 940A of the liquid crystal display panel 6 is bonded to the surface portion 721 of the first circuit board 72 by wire bonding a high frequency analog IC 93A and a signal processing digital IC 94A that are sources of high frequency noise. The sensitivity of the arm-mounted communication device 1 of this example directed toward the side is −3.0 dB in terms of relative sensitivity with respect to the reference sensitivity.

  On the other hand, the active surfaces 930B and 940B are connected to the loop antenna 4 by wire-bonding a high-frequency analog IC 93B and a signal processing digital IC 94B that are sources of high-frequency noise to the back surface portion 732 of the second circuit board 73. The sensitivity of the conventional arm-mounted communication device toward the side is −2.0 dB in terms of relative sensitivity with respect to the reference sensitivity. That is, according to the arrangement structure of the present example, the high frequency noise radiated from the active surfaces 930A and 940A of the high frequency analog IC 93A and the signal processing digital IC 94A is indicated by an arrow C in FIG. In the conventional arrangement structure, the high frequency noise radiated from the active surfaces 930B and 940B of the high frequency analog IC 93B and the signal processing digital IC 94B is shown by an arrow D in FIG. As shown, since high frequency noise is radiated toward the loop antenna 4, according to the arrangement structure of this example, the sensitivity is improved by 1.0 dB compared to the arrangement structure of the comparative example.

  In FIG. 10, in the arm-mounted communication device 1 using the arrangement structure of this example, the sensitivity in a finished product state is represented by a broken line L <b> 7 </ b> A and should be arranged on the back side of the second circuit board 73. Sensitivity when the back cover is removed is represented by a polygonal line L8A, and sensitivity when the back cover to be arranged on the back side of the second circuit board 73 and the circuit driving battery 8 is removed is represented by a polygonal line L9A. The sensitivity in the case where the communication device is configured by only the second circuit boards 72 and 73 is indicated by a broken line L10A. FIG. 11 shows the sensitivity of the conventional arm-mounted communication device in a finished product as a broken line L7B, with the back cover to be placed on the back side of the second circuit board 73 removed. The sensitivity is represented by a polygonal line L8B, the sensitivity in a state where the back cover to be arranged on the back side of the second circuit board 73 and the circuit driving battery 8 is removed is represented by a polygonal line L9B, and the first and second circuit boards 72 are provided. , 73, the sensitivity when the communication apparatus is configured is represented by a broken line L10B.

  Note that the vertical axis in FIGS. 10 and 11 represents the relative sensitivity when the reference sensitivity level is 0 dB. 10 and FIG. 11, the sensitivity is improved as it is closer to the finished product regardless of the arrangement structure, but the sensitivity obtained from the sensitivity characteristics shown in FIG. 10 and FIG. 11 is compared with Table 2. Thus, under any conditions, the sensitivity is higher when the arrangement structure to which the present invention is applied is adopted.

  In Table 2, the arm-mounted communication device having the same structure and the same specification is shown in parentheses, but the sensitivity measured with another sample is shown. Moreover, the numerical value in Table 2 is an average value of the measured value in each graph shown in FIG. 10 and FIG.

  Further, in FIG. 12, the sensitivity in a state where the arm-mounted communication device 1 using the arrangement structure of this example is used as a finished product using this different sample is represented by a broken line L7A, and the second circuit board 73 is shown. The sensitivity in a state where the back cover to be arranged on the back surface side of the second circuit board 73 is removed is represented by a broken line L8A, and the sensitivity in the state where the back cover to be arranged on the back surface side of the second circuit board 73 and the circuit driving battery 8 are removed. Is represented by a polygonal line L9A, and the sensitivity when the communication device is constituted by only the first and second circuit boards 72 and 73 is represented by a polygonal line L10A.

  Further, in FIG. 13, the sensitivity in a state of being a completed product in another conventional arm-mounted communication device using another sample is represented by a broken line L7B and should be arranged on the back side of the second circuit board 73. Sensitivity in a state where the back cover is removed is represented by a polygonal line L8B, and sensitivity in a state where the back cover to be disposed on the back side of the second circuit board 73 and the circuit driving battery 8 is removed is represented by a polygonal line L9B. The sensitivity when the communication device is configured by only the second circuit boards 72 and 73 is indicated by a broken line L10B.

  The vertical axis in FIGS. 12 and 13 represents the relative sensitivity when the reference sensitivity level is 0 dB.

  As a result, as can be seen from Table 2, FIG. 12, and FIG. 13, it is confirmed that if the arrangement structure of this example is used, the effect of improving the sensitivity is reproducible even when the sample is changed. is made of.

(Example 3)
In the first and second embodiments, the arm-mounted communication has a device main body whose side on which the display surface is configured is the front surface side, and an antenna body configured as an arm band for mounting the device main body on the arm. In an apparatus, an IC that generates high-frequency noise is mounted on a circuit board such that the active surface faces the display surface side (the direction opposite to the side where the whole or most of the antenna body is located with respect to the circuit board). However, as shown in FIGS. 14A and 14B, the present invention can also be applied to a communication apparatus in which an IC and an antenna body are configured on the same circuit board.

  FIG. 14A is a perspective view schematically showing the arrangement of the antenna body and the circuit board in the communication apparatus according to the third embodiment, and FIG. 14B is a side view of this arrangement structure. As shown in FIG. 14A, the communication apparatus of this example includes a circuit board 74 on which various electronic components are mounted, and an antenna body configured on the one board surface 741 side with respect to the circuit board 74. 41. Of the electronic components, all of the ICs that generate high-frequency noise such as the high-frequency analog IC 96 and the signal processing digital IC 97 are mounted on the circuit board 74 on the same substrate surface 741 side as the antenna body 41.

  However, since the high frequency analog IC 96 and the digital IC 97 for signal processing are face-down bonded to the circuit board 74 as shown in FIG. 14B, the antenna body 41 is positioned with respect to the circuit board 74. The active surfaces 960 and 970 face in the direction opposite to the direction. Therefore, in the communication apparatus of this example, even if high frequency noise is emitted from the high frequency analog IC 96, the digital IC 97 for signal processing or the active surfaces 960 and 970, as indicated by the arrow E, the influence of the high frequency noise is affected by the antenna body. Since it is difficult to reach 41, the sensitivity is high.

Example 4
FIG. 15A is a perspective view schematically showing the arrangement of the antenna body and the circuit board in the communication apparatus according to the fourth embodiment, and FIG. 15B is a side view of this arrangement structure. As shown in FIG. 15A, the communication device of this example includes a circuit board 75 on which various electronic components are mounted, and an antenna body configured on the one board surface 751 side with respect to the circuit board 75. 42. Of the electronic components, any IC that generates high-frequency noise, such as a high-frequency analog IC 98 or a digital IC 99 for signal processing, is mounted on the board surface 752 side opposite to the antenna body 42 with respect to the circuit board 75. Yes.

  However, since the high frequency analog IC 98 and the signal processing digital IC 99 are wire-bonded to the circuit board 75 as shown in FIG. 15B, the direction in which the antenna body 42 is located with respect to the circuit board 75. The active surfaces 980 and 990 face in the direction opposite to the first side. Therefore, even in the communication apparatus of this example, even if the high frequency analog IC 98 or the digital IC 99 for signal processing emits high frequency noise from the active surfaces 980 and 990 as indicated by the arrow F, the influence of the high frequency noise is not affected by the antenna body. Since it is difficult to reach 941, the sensitivity is high.

(Other examples)
In any of the embodiments, the case where a loop antenna is used as the antenna body has been described. However, a slot antenna may be configured by forming a slit in the longitudinal direction of the antenna body.

  Further, not only when the antenna body is configured on the same circuit board on which the IC is mounted, but also when the antenna body is configured on a base other than the circuit board, an IC that generates high-frequency noise. However, if the active circuit is mounted on the circuit board so that the active surface faces in the direction opposite to the direction in which the whole or most of the antenna body is located with respect to the circuit board, the integrated circuit generates high-frequency noise from the active surface. However, since the effect of the high frequency noise is difficult to reach the antenna body, an effect of high sensitivity can be obtained.

  Further, the present invention can be applied to any type of communication device such as a wristwatch with FM radio, a wristwatch-type individual selective call receiver, a pocket-type pager, a mobile phone, and a PHS.

It is explanatory drawing which shows the whole structure of the arm mounting | wearing type communication apparatus of this invention. (A) is a top view of the circuit assembly mounted in the communication apparatus shown in FIG. 1, (b) is the bottom view. (A) is explanatory drawing which shows typically a cross section when the circuit assembly which concerns on Example 1 shown in FIG. 2 is cut | disconnected by the IV-IV 'line, (b) is the circuit assembly which concerns on a comparative example Explanatory drawing which shows a cross section when cut | disconnecting in the position equivalent to the IV-IV 'line | wire shown in FIG. The graph which shows the sensitivity characteristic of the communication apparatus shown to Fig.3 (a) compared with the sensitivity characteristic of the arm mounting | wearing type communication apparatus using the arrangement structure which concerns on the comparative example shown in FIG.3 (b). FIG. 4 is a graph showing sensitivity characteristics when the assembly state is changed in the arm-mounted communication device using the arrangement structure according to the first embodiment shown in FIG. FIG. 4 is a graph showing sensitivity characteristics when the assembly state is changed in the communication device shown in FIG. The evaluation shown in FIG. 5 is a graph showing sensitivity characteristics when the assembly state is changed in the communication device shown in FIG. FIG. 6 is a graph showing sensitivity characteristics when the assembly state is changed in the communication device shown in FIG. (A) is explanatory drawing which shows typically a cross section when the circuit assembly which concerns on Example 2 shown in FIG. 2 is cut | disconnected by the IV-IV 'line, FIG.9 (b) is the circuit which concerns on a prior art example. Explanatory drawing which shows a cross section when an assembly is cut | disconnected in the position corresponded to IV-IV 'line. The graph which shows the sensitivity characteristic when an assembly state is changed in the arm mounting type communication apparatus using the arrangement structure which concerns on Example 2 shown to Fig.9 (a). The graph which shows the sensitivity characteristic when an assembly state is changed in the arm mounting type communication apparatus using the arrangement structure which concerns on the prior art example shown in FIG.9 (b). FIG. 10 is a graph showing sensitivity characteristics when the assembly state is changed in the communication device used in Example 2 shown in FIG. 11 is a graph showing sensitivity characteristics when the assembly state is changed in the communication device according to the conventional example shown in FIG. (A) is a perspective view which shows typically arrangement | positioning of the antenna body and circuit board in the communication apparatus which concerns on Example 3, (b) is a side view of this arrangement structure. (A) is a perspective view which shows typically arrangement | positioning of the antenna body and circuit board in the communication apparatus which concerns on Example 4, (b) is a side view of this arrangement structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arm-mounted communication apparatus, 2 apparatus main body, 4 loop antenna (antenna body), 4R, 4L arm band, 5 circuit assembly, 6 liquid crystal display panel (display surface), 41, 42 antenna body, 71, 72, 73, 74, 75 Circuit board, 90A, 95A Digital IC for processing display data, 91A, 93A, 96, 98 High frequency analog IC for generating high frequency noise, 92A, 94A, 97, 99 Signal for generating high frequency noise Active surface of processing digital IC 910A, 920A, 930A, 940A, 960, 970, 980, 990 IC.

Claims (3)

  In a communication apparatus having a substrate on which an integrated circuit that generates high-frequency noise is mounted and an antenna body that is located entirely or mostly on one substrate surface side of the substrate, the integrated circuit is connected to the substrate. The communication device is mounted on the substrate such that an active surface faces in a direction opposite to a direction in which the whole or most of the antenna body is located.   2. The apparatus main body according to claim 1, comprising: an apparatus main body on which a display surface is configured as a front surface side; and an arm band that extends from the apparatus main body to a rear surface side and attaches the apparatus main body to an arm. The communication apparatus, wherein the antenna body is configured in a band, and the substrate is disposed on a back side of the display surface in the apparatus main body. 3. The integrated circuit according to claim 1, wherein the integrated circuit includes at least one of a high-frequency analog integrated circuit having at least one of a transmission function and a reception function, and a signal processing digital integrated circuit driven by a high-frequency drive signal. A communication device, which is one integrated circuit.

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