Patent Publication Number: US-9894753-B2

Title: Wireless communication module and solar photovoltaic system

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a Continuation of application Ser. No. 15/169,080, filed May 31, 2016, which is a Division of application Ser. No. 13/850,777, filed Mar. 26, 2013 (now U.S. Pat. No. 9,380,724, issued Jun. 28, 2016), which is based upon and claims the benefit of priority from Japanese Patent Application Nos. 2012-70974, filed on Mar. 27, 2012, and 2013-49891, filed on Mar. 13, 2013, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a wireless communication module, an LED lighting device, a solar photovoltaic system, a self-start system and a detection device. 
     BACKGROUND 
     In recent years, wireless communication units have been modularized. For example, Bluetooth modular devices with high productivity have been proposed, which provide compatibility irrespective of internal and external antenna specifications of an apparatus configuring a system. 
     In the related art, it is required that a set maker should connect a wireless communication module to a microcomputer to process an output from the wireless communication module. However, since the wireless communication module and the microcomputer are required to be interconnected by a number of signal lines, the set maker may have an increased burden of circuit design. 
     It is therefore contemplated that a wireless communication circuit (or RF (Radio Frequency) circuit) and a microcomputer is integrated and mounted on a single board. However, such a wireless communication module may result in an increase in board area and module size due to parallel arrangement of the RF circuit and the microcomputer. In addition, the board on which the RF circuit is mounted is required to be a multi-layered board made of a high-k material since the RF circuit operates with a high frequency. Accordingly, when the RF circuit and the microcomputer are mounted on the single board, the multi-layered board made of a high-k material is compelled to be unnecessarily used for the microcomputer, which may result in increased costs. 
     SUMMARY 
     The present disclosure provides some embodiments of a wireless communication module, an LED lighting device, a solar photovoltaic system, a self-start system and a detection device which are capable of achieving compactness while integrating an RF circuit with a microcomputer and realizing reduction in production costs. 
     According to one embodiment of the present disclosure, there is provided a wireless communication module including: a wireless circuit configured to transmit/receive a wireless signal; a first inter-board connector; a first board on which the wireless circuit and the first connector are mounted; a signal processing circuit configured to process the wireless signal transmitted/received by the wireless circuit; a second inter-board connector configured to be connected to the first connector; and a second board on which the signal processing circuit and the second connector are mounted, wherein the first board overlaps at least partially with the second board under a condition where the first connector and the second connector are interconnected. 
     According to another embodiment of the present disclosure, there is provided an LED lighting device including the above-described wireless communication module. 
     According to another embodiment of the present disclosure, there is provided a solar photovoltaic system including the above-described wireless communication module. 
     According to another embodiment of the present disclosure, there is provided a self-start system including: the above-described wireless communication module configured to receive an external signal; and an operation part configured to perform a predetermined ON/OFF switching function based on the received external signal of the wireless communication module. 
     According to another embodiment of the present disclosure, there is provided a detection device including: a sensor configured to detect a predetermined state; and the above-described wireless communication module configured to transmit a detection signal of the sensor in a wireless manner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A to 1C  are schematic configuration views showing an example configuration of a wireless communication module according to a first embodiment,  FIG. 1A  being a schematic side view,  FIG. 1B  being a schematic plan view and  FIG. 1C  being another schematic plan view. 
         FIG. 2  is a schematic block diagram showing an example configuration of an RF circuit according to the first embodiment. 
         FIGS. 3A and 3B  are views illustrating an RF board according to the first embodiment,  FIG. 3A  being a schematic sectional view and  FIG. 3B  being a schematic plan view. 
         FIG. 4  is a schematic view showing an external appearance of an application of the wireless communication module of the first embodiment to an LED lighting device. 
         FIG. 5  is a schematic block diagram showing an application of the wireless communication module of the first embodiment to a solar photovoltaic system. 
         FIGS. 6A and 6B  are schematic configuration views showing an example configuration of a wireless communication module according to a second embodiment,  FIG. 6A  being a schematic side view and  FIG. 6B  being a schematic plan view. 
         FIGS. 7A and 7B  are schematic configuration views showing an example configuration of a wireless communication module according to a third embodiment,  FIG. 7A  being a schematic side view and  FIG. 7B  being a schematic plan view. 
         FIGS. 8A and 8B  are schematic configuration views showing an example configuration of another wireless communication module according to the third embodiment,  FIG. 8A  being a schematic side view and  FIG. 8B  being a schematic plan view. 
         FIG. 9  is a schematic configuration view showing an example configuration of a wireless communication module according to a fourth embodiment. 
         FIG. 10  is a schematic configuration view showing an example configuration of a wireless communication module according to a fifth embodiment. 
         FIG. 11  is a schematic configuration view showing an example configuration of a wireless communication module according to a sixth embodiment. 
         FIG. 12  is a schematic configuration view showing an example configuration of a wireless communication module according to a seventh embodiment. 
         FIGS. 13A and 13B  are schematic configuration views showing an example configuration of the wireless communication module according to the first embodiment,  FIG. 13A  being a schematic side view and  FIG. 13B  being a schematic plan view showing an inner board side of a control board. 
         FIGS. 14A to 14D  are schematic configuration views showing an example configuration of a wireless communication module according to an eighth embodiment,  FIG. 14A  being a schematic side view,  FIG. 14B  being a schematic plan view showing an inner board side of a control board,  FIG. 14C  being a schematic enlarged sectional view and  FIG. 14D  being another schematic enlarged sectional view. 
         FIGS. 15A and 15B  are schematic configuration views showing an example configuration of a wireless communication module according to a ninth embodiment. 
         FIGS. 16A and 16B  are schematic configuration views showing an example configuration of a wireless communication module according to a tenth embodiment,  FIG. 16A  being a schematic plan view and  FIG. 16B  being a schematic side view. 
         FIGS. 17A and 17B  are schematic configuration views of the RF board shown in  FIGS. 16A and 16B ,  FIG. 17A  being a schematic plan view and  FIG. 17B  being a schematic side view. 
         FIGS. 18A to 18C  are schematic configuration views of the control board shown in  FIGS. 16A and 16B ,  FIG. 18A  being a schematic plan view,  FIG. 18B  being a schematic front view and  FIG. 18C  being a schematic side view. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention(s). However, it will be apparent to one of ordinary skill in the art that the present invention(s) may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments. 
     Embodiments of the present disclosure will now be described in detail with reference to the drawings. Throughout the drawings, the same or similar elements are denoted by the same or similar reference numerals. It is however noted that the drawings are just schematics, and relationships between thickness and planar dimension of elements, thickness ratios of various layers and so on may be unrealistic. Accordingly, detailed thickness and dimensions should be determined in consideration of the following description. In addition, it is to be understood that the figures include different dimensional relationships and ratios. 
     The following embodiments are provided to illustrate devices and methods to embody the technical ideas of the present disclosure and are not limited to materials, forms, structures, arrangements and so on of elements detailed herein. The embodiments of the present disclosure may be modified in different ways without departing from the spirit and scope of the invention defined in the claims. 
     [First Embodiment] 
     A first embodiment will now be described with reference to  FIGS. 1A to 5 . 
     A wireless communication module  1  according to the first embodiment includes an RF circuit  12  for transmitting/receiving wireless signals, an inter-board connector  11 , an RF board  10  mounted thereon with the RF circuit  12  and the connector  11 , a microcomputer  22  for processing the wireless signals transmitted/received by the RF circuit  12 , an inter-board connector  21  which can be connected to the connector  11 , and a control board  20  mounted thereon with the microcomputer  22  and the connector  21  and is configured such that the RF board  10  and the control board  20  are at least partially overlapped with each other when the connector  11  and the connector  21  are interconnected. 
     In addition, the RF board  10  and the control board  20  may be arranged such that a board side of the RF board  10  on which the RF circuit  12  is mounted faces a board side of the control board  20  on which the microcomputer  22  is not mounted. 
     In addition, an antenna  13  may be arranged in a region on the RF board  10  in which the RF board  10  and the control board  20  do not overlap with each other. 
     In addition, the RF board  10  may be a multi-layered board made of a material having a higher dielectric constant than the control board  20 . 
     (Wireless Communication Module) 
       FIGS. 1A to 1C  are schematic configuration views showing an example configuration of the wireless communication module  1  according to the first embodiment,  FIG. 1A  being a schematic side view and  FIG. 1B  being a schematic plan view. As shown in these figures, the wireless communication module  1  includes two boards, i.e., the RF board  10  and the control board  20 , which are connected in a three dimensional manner by the connectors  11  and  21 . In the following description, board sides in which the two boards  10  and  20  face with each other are called “inner board sides” and opposite board sides are called “outer board sides.” 
     The RF circuit  12  and the connector  11  are mounted on the inner board side of the RF board  10 . The RF circuit  12  is a wireless circuit for transmitting/receiving wireless signals and operates with a high frequency. The connector  11  is a thin inter-board connector which is commonly called a “board-to-board connector.” 
     The connector  21  is mounted on the inner board side of the control board  20 . The connector  21  is a thin inter-board connector which can be connected to the connector  11 . In addition, the microcomputer  22 , other electronic part  23  and a connector  24  are mounted on the outer board side of the control board  20 . The microcomputer  22  is a signal processing unit for processing the wireless signals transmitted/received by the RF circuit  12 . The connector  24  is used to provide external connection. 
     When the connector  11  is connected to the connector  21 , the RF board  10  faces the control board  20 . The RF circuit  12  is interposed between the two boards  10  and  20 , and the microcomputer  22  and the other electronic part  23  are arranged on the outer board side of the control board  20 . As shown in these figures, the RF board  10  is larger in size than the control board  20  and has a projecting right end when viewed from the plane view of  FIGS. 1B and 1C . When the antenna  13  is disposed on the projecting right end of the RF board  10 , deteriorated sensitivity of the antenna  13  can be avoided since electromagnetic waves can be prevented from being interrupted by metal parts or the like. 
       FIG. 1C  is a schematic plan view showing one example of a connection between the antenna  13  and the RF circuit  12 . As shown in this figure, the antenna  13  and an external antenna  13   a , which will be described in detail later, are connected to the RF circuit  12  via a switch  13   d . The switch  13   d  includes a first connection portion connected to the external antenna  13   a  and a second connection portion connected to the antenna  13 . If the antenna  13  is used to transmit/receive the wireless signals, the switch  13   d  is fixed with the antenna  13  connected to the second connection portion. On the other hand, if the external antenna  13   a  is used to transmit/receive the wireless signals, the switch  13   d  is fixed with a cable  13   b  of the external antenna  13   a  connected to the first connection portion. Other configurations are the same as those in  FIG. 1B . 
     (RF Circuit) 
       FIG. 2  is a block diagram showing an example configuration of the RF circuit  12  according to the first embodiment. The RF circuit  12  includes a power supply  121 , a filter  122 , an RF switch  123 , a transmitter  124 , a receiver  125 , a modem  126 , a controller  127  and a signal generator  128 . These components  121  to  128  are covered by a metal shield plate  120  including a flat top portion and four side portions. The shield plate  120  has an internal cavity. The side portions can be fixed to the RF board  10  while covering the RF circuit  12 . The side portions may be soldered to a pad connected to a ground of the RF board  10 . That is, the shield plate  120  is fixed to the RF board  10  while making electrical connection to the ground of the RF board  10 . In addition, the shield plate  120  may be made of, for example, resin, instead of metal. In this case, the shield plate  120  is fixed to the RF board  10  by means of, for example, an adhesive. The transmitter  124 , the receiver  125 , the modem  126  and the controller  127  in the RF circuit  12  constitute a single RFIC unit  129 . The power supply  121  converts direct current of a voltage into direct current of a different voltage, which is then supplied to the modem  126 , the controller  127  and so on. The signal generator  128  generates a clock signal to be supplied to the modem  126 , the controller  127  and so on. The controller  127  performs various controls for wireless communication. The modem  126  performs frequency modulation based on a modulation scheme such as GFSK (Gaussian Frequency-Shift Keying) or the like. The RF switch  123  is used to switch between transmission and reception of the wireless signals. The filter  122  for reducing noises is connected to the antenna  13  via an antenna connector  13   c.    
     (RF Board and Control Board) 
       FIGS. 3A and 3B  are views illustrating the RF board  10  according to the first embodiment,  FIG. 3A  being a schematic sectional view and  FIG. 3B  being a schematic plan view. The RF board  10  is required to use a multi-layered board made of a high-k material since the RF circuit  12  operates with a high frequency. The RF board  10  may be a multi-layered board of, for example, four to six layers. As shown in these figures, the RF board  10  includes a strip line  31 . The strip line  31  corresponds to a line between the connector  13   c  and the RF switch  123 , a line between the RF switch  123  and the transmitter  124 , and a line between the RF switch  123  and the receiver  125 , as indicated by thick lines in  FIG. 2 . In  FIGS. 3A and 3B , reference numerals  32  and  33  denote a ground pattern and a via hole, respectively. The RF board  10  is made of a high-k material such as glass epoxy, alumina, SiN, SiF or the like. The control board  20  need not be a multi-layered board made of a high-k material but may be a single layer board made of, for example, glass epoxy. 
     (Applications) 
       FIG. 4  is a schematic view showing an external appearance of an application of the wireless communication module  1  of the first embodiment to an LED lighting device. The connector  24  of the wireless communication module  1  is connected to a connector  24   b  of an LED power module  2  via a harness  24   a . This LED lighting device allows a user to perform an operation such as lighting-ON/OFF from another room by exchanging a wireless signal with a remote controller. In addition, as shown in  FIG. 4 , if a detection device  300  including a sensor  100  for detecting the presence of a person (or a certain condition) and a wireless transmitter  200  for transmitting a detection signal by wireless are combined with the LED lighting device, then this constitutes a system which automatically switches between lighting ON and OFF depending on whether or not the presence of a person is detected by the sensor  100 . In this case, the wireless transmitter  200  for transmitting the detection signal of the sensor  100  in a wireless manner can be configured with the wireless communication module  1  according to this embodiment. 
       FIG. 5  is a schematic block diagram showing an application of the wireless communication module  1  of the first embodiment to a solar photovoltaic system. A power conditioner  4  converts electricity generated by a solar cell  3  into AC electric power available for households  7 . In addition, surplus electric power may be sold to an electric power company  6 . The wireless communication modules  1  are mounted on the power conditioner  4  and its remote controller  5 , respectively. This allows a wireless signal to be exchanged between the power conditioner  4  and the remote controller  5 , thereby allowing the display of various kinds of data such as quantity of generated electricity, power consumption and the like on a monitor  5   a  of the remote controller  5 . 
     Without being limited to the above examples of application, the wireless communication module  1  may be applied to an automatic operation system (or self-start system) having an ON/OFF switching function based on a signal from a sensor or a signal from a manipulation by a user (e.g., a remote controller manipulation). In other words, this automatic operation system is a system including the wireless communication module  1  to receive an external signal and an operation part to perform a predetermined ON/OFF switching function based on the received external signal of the wireless communication module  1 . For example, this automatic operation system employing the wireless communication module  1  is suitable to be applied to automatic door opening/closing, escalator running/stopping, lighting ON/OFF, alarm ON/OFF, automatic faucet, automatic cleaning and so on based on detection of existence of a person. In addition, as described above, the wireless communication module  1  may be used as a transmitter. In addition, a detection object of the sensor  100  may be a physical quantity such as temperature, pressure and the like without being limited to the existence of living things including people. 
     As described above, the wireless communication module  1  according to the first embodiment is configured such that the RF board  10  and the control board  20  overlap with each other with the connecter  11  and the connector  21  interconnected. This allows parts to be mounted in a three dimensional manner, thereby providing a decreased size while integrating the RF circuit  12  with the microcomputer  22 . In addition, the control board  20  can be made of an inexpensive material, thereby achieving reduction in costs. In addition, the RF board  10  and the control board  20  are separated from each other, thereby allowing each user to customize only the microcomputer  22  and hence to strengthen or modify the functions of the wireless communication module  1 . 
     In addition, in this embodiment, the RF board  10  and the control board  20  are arranged such that the board side on which the RF circuit  12  is mounted faces the board side on which the microcomputer  22  is not mounted. That is, since only parts of the RF board  10  are arranged between the RF board  10  and the control board  20 , it is possible to provide a thin wireless communication module  1 . 
     [Second Embodiment] 
     A configuration of a wireless communication module  1  according to a second embodiment will be now described with reference to  FIGS. 6A and 6B , with an emphasis placed on differences from that of the first embodiment. 
     (Wireless Communication Module) 
       FIGS. 6A and 6B  are schematic configuration views showing an example configuration of the wireless communication module  1  according to the second embodiment,  FIG. 6A  being a schematic side view and  FIG. 6B  being a schematic plan view. The second embodiment has the same configuration as the first embodiment except that the antenna  13   a  is externally attached. Specifically, the antenna connector  13   c  is mounted on the inner board side of the RF board  10  and the antenna  13   a  is connected to the antenna connector  13   c  via the cable  13   b . In this case, the RF board  10  may have substantially the same size as the control board  20 , as shown in  FIGS. 6A and 6B . 
     As described above, the wireless communication module  1  according to the second embodiment allows the antenna  13   a  to be externally attached, thereby making it possible to further reduce the size of the RF board  10  over that in the first embodiment. 
     [Third Embodiment] 
     A configuration of a wireless communication module  1  according to a third embodiment will be now described with reference to  FIGS. 7A to 8B , with an emphasis placed on differences from those of the first and second embodiments. 
     (Wireless Communication Module) 
       FIGS. 7A and 7B  are schematic configuration views showing an example configuration of the wireless communication module  1  according to the third embodiment,  FIG. 7A  being a schematic side view and  FIG. 7B  being a schematic plan view. The third embodiment has the same configuration as the first embodiment except that the antenna  13  is sandwiched between the RF board  10  and the control board  20 . In other words, the antenna  13  may be interposed between the RF circuit  12  and the control board  20  as long as metal parts and the like are not placed near the antenna  13 . 
     Specifically, the antenna  13  is disposed in a region on the RF board  10  in which the RF board  10  and the control board  20  overlap with each other, and the microcomputer  22  is disposed outside a near-region E 2  of the antenna  13 . As used herein, the term “near-region E 2  of the antenna  13 ” refers to a region which is likely to have an effect on a radio wave state of the antenna  13 . More specifically, the antenna  13  and the microcomputer  22  are arranged in a non-overlapping manner when viewed from a direction in which the RF board  10  and the control board  20  overlap with each other (for example, a point of view of  FIG. 7B ). However, it is to be understood that the microcomputer  22  is not limited to the exact position in  FIGS. 7A and 7B  as long as it can be positioned within a region El which is not near the antenna  13 . In addition to the microcomputer  22 , the connector  24  for external connection, the other electronic part  23 , and the wiring pattern on the control board  20  are positioned to avoid the region E 2 . 
       FIGS. 8A and 8B  are schematic configuration views showing an example configuration of another wireless communication module  1  according to the third embodiment,  FIG. 8A  being a schematic side view and  FIG. 8B  being a schematic plan view. The wireless communication module  1  shown in  FIGS. 8A and 8B  is similar to that shown in  FIGS. 7A and 7B  in that the antenna  13  is interposed between the RF board  10  and the control board  20  but is different from that shown in  FIGS. 7A and 7B  in that the antenna  13  is disposed in the central portion of the RF board  10  instead of being disposed in the right end of the RF board  10 . In this case, the connector  24 , the microcomputer  22 , the other electronic part  23  and so on are arranged to avoid the near-region E 2  of the antenna  13  as well. 
     As described above, the wireless communication module  1  according to the third embodiment is configured such that the antenna  13  is interposed between the RF board  10  and the control board  20 . Also in this case, since various parts and wiring patterns on the control board  20  are arranged to avoid the near-region E 2  of the antenna  13 , it is possible to avoid deteriorated sensitivity of the antenna  13 . 
     [Fourth Embodiment] 
     A configuration of a wireless communication module  1  according to a fourth embodiment will be now described with reference to  FIG. 9 , with an emphasis placed on differences from those of the first to third embodiments. 
     (Wireless Communication Module) 
       FIG. 9  is a schematic configuration view showing an example configuration of the wireless communication module  1  according to the fourth embodiment. The fourth embodiment is different from the first embodiment in that the inner board side of the control board  20  (a board side of the control board  20  which faces the RF board  10 ) and the top of the shield plate  120  of the RF circuit  12  are fixed together by means of an adhesive  31 . Material of the adhesive  31  and a method of applying the adhesive  31  are not particularly limited. For example, a double-sided tape may be used for the adhesive  31 . The adhesive  31  may be made of an insulating material. 
     As described above, in the wireless communication module  1  according to the fourth embodiment, the inner board side of the control board  20  is fixed to the RF circuit  12  by means of the adhesive  31 . This can provide a higher connection strength than the connection between the RF board  10  and the control board  20  by means of only the connectors  11  and  21 . 
     [Fifth Embodiment] 
     A configuration of a wireless communication module  1  according to a fifth embodiment will be now described with reference to  FIG. 10 , with an emphasis placed on differences from those of the first to fourth embodiments. 
     (Wireless Communication Module) 
       FIG. 10  is a schematic configuration view showing an example configuration of the wireless communication module  1  according to the fifth embodiment. The fifth embodiment is different from the first embodiment in that the RF board  10  and the control board  20  are fixed together by means of screws  32   a  and  32   b . The screws  32   a  and  32   b  may be positioned at any suitable places such as four corners of the control board  20 . 
     As described above, in the wireless communication module  1  according to the fifth embodiment, the RF board  10  and the control board  20  are fixed together by means of the screws  32   a  and  32   b . This can provide higher connection strength than connection between the RF board  10  and the control board  20  by means of only the connectors  11  and  21 . 
     [Sixth Embodiment] 
     A configuration of a wireless communication module  1  according to a sixth embodiment will be now described with reference to  FIG. 11 , with an emphasis placed on differences from those of the first to fifth embodiments. 
     (Wireless Communication Module) 
       FIG. 11  is a schematic configuration view showing an example configuration of the wireless communication module  1  according to the sixth embodiment. The sixth embodiment is different from the first embodiment in that the RF board  10  and the control board  20  are fixed together by means of locking supports  33   a  and  33   b . The locking supports  33   a  and  33   b  may be positioned at any suitable place such as four corners of the control board  20 . 
     As described above, in the wireless communication module  1  according to the sixth embodiment, the RF board  10  and the control board  20  are fixed together by means of the locking supports  33   a  and  33   b . This can provide higher connection strength than connection between the RF board  10  and the control board  20  by means of only the connectors  11  and  21 . 
     [Seventh Embodiment] 
     A configuration of a wireless communication module  1  according to a seventh embodiment will be now described with reference to  FIG. 12 , with an emphasis placed on differences from those of the first to sixth embodiments. 
     (Wireless Communication Module) 
       FIG. 12  is a schematic configuration view showing an example configuration of the wireless communication module  1  according to the seventh embodiment. The seventh embodiment is different from the first embodiment in that two pairs of inter-board connectors are provided at two separate places, respectively. Specifically, in addition to the connector  11  provided in the left end of the RF board  10 , a connector  15  is provided in the right end of the RF board  10 . Further, in addition to the connector  21  provided in the left end of the control board  20 , a connector  25  is provided in the right end of the control board  20 . 
     As described above, in the wireless communication module  1  according to the seventh embodiment, the two pairs of inter-board connectors are provided at the two separate places, respectively. This can provide higher connection strength than the connection between the RF board  10  and the control board  20  by means of only the connectors  11  and  21 . 
     [Eighth Embodiment] 
     A configuration of a wireless communication module  1  according to an eighth embodiment will be now described with reference to  FIGS. 13A to 14D , with an emphasis placed on differences from those of the first to seventh embodiments. 
     (Wireless Communication Module) 
     With the first embodiment, there is a possibility of contact of the inner board side of the control board  20  with the top of the shield plate  120  of the RF circuit  12 . Specifically, as shown in  FIGS. 13A and 13B , since some gap is present between the control board  20  and the RF circuit  12 , there is a possibility of contact to a region E 3  on the inner board side of the control board  20 , which faces the RF circuit  12 , with the RF circuit  12  under application of a load to the wireless communication module  1 . For this reason, wiring patterns to be formed on the inner board side of the control board  20  need to be arranged outside the region E 3 . 
       FIGS. 14A and 14B  are schematic configuration views showing an example configuration of the wireless communication module  1  according to the eighth embodiment,  FIG. 14A  being a schematic side view and  FIG. 14B  being a schematic plan view showing the inner board side of the control board  20 .  FIGS. 14C and 14D  are schematic enlarged sectional views of a dot-circled portion in  FIG. 14A . As shown in these figures, projections  14  projecting toward the control board  20  are respectively formed in four corners of the top of the shield plate  120  covering the RF circuit  12 , which faces the control board  20 . This prevents the shield plate  120  from contacting the control board  20  except the projections  14 . Accordingly, as shown in  FIG. 14C , signal wiring patterns L 1  can be formed on the inner board side of the control board  20  in regions except the projections  14  (i.e., regions other than regions E 4 ). However, ground wiring patterns L 2  are, for example, formed in the regions E 4  contacting the projections  14 . Thus, the shield plate  120  can serve as a ground. 
     The projections  14  may be formed of an elastically deformable spring which can be integrated with the shield plate  120  as shown in  FIG. 14D . The RF board  10  and the control board  20  are interconnected and fixed together with the projections  14  being bent. That is, when the RF board  10  and the control board  20  are interconnected, the projections  14  make contact with the control board  20  under a condition where the projections  14  are bent. This ensures reliable contact of the ground wiring patterns L 2  of the control board  20  with the shield plate  120 , for example even if the height of the projections  14  is uneven. In this case, since the control board  20  is pressed upward by the projections  14 , the spring connector  11  and  21  and so on may be under load. Accordingly, for example, the RF board  10  and the control board  20  may be interconnected and fixed together at multiple sites. 
     As described above, the wireless communication module  1  according to the eighth embodiment is provided with the projections  14  formed in the four corners of the top of the shield plate  120 , which faces the control board  20 . This prevents the shield plate  120  from contacting the control board  20  except the projections  14 , thereby providing an extended region on the inner board side of the control board  20  in which the signal wiring patterns L 1  can be formed. 
     In addition, the ground wiring patterns L 2  are formed in the regions contacting the projections  14 . This allows the shield plate  120  to serve as a ground, which may result in an increased ground area contributing to circuit stability. In addition, the projections  14  and the ground wiring patterns L 2  (or pads) of the control board  20  may be fixed together by means of a conductive adhesive. 
     [Ninth Embodiment] 
     A configuration of a wireless communication module  1  according to a ninth embodiment will be now described with reference to  FIGS. 15A and 15B , with an emphasis placed on differences from those of the first to eighth embodiments. 
     (Wireless Communication Module) 
       FIGS. 15A and 15B  are schematic configuration views showing an example configuration of the wireless communication module  1  according to the ninth embodiment. The ninth embodiment is different from the first embodiment in that the RF circuit  12  and the control board  20  are arranged in a reversed fashion. That is, the RF circuit  12  and the control board  20  are arranged such that a board side of the RF board  10  on which the RF circuit  12  is not mounted faces a board side of the control board  20  on which the microcomputer  22  is mounted. In this case, in order to prevent the microcomputer  22  from contacting the inner board side of the RF board  10 , a spacer S is interposed between the RF board  10  and the control board  20 . It is to be understood that the spacer S may be appropriately changed in its height, shape and the like. 
     As described above, in the wireless communication module  1  according to the ninth embodiment, the RF circuit  12  and the control board  20  are arranged such that the board side of the RF board  10  on which the RF circuit  12  is not mounted faces the board side of the control board  20  on which the microcomputer  22  is mounted. Like the first embodiment, this configuration can also provide a reduced size of the wireless communication module  1  while integrating the RF circuit  12  with the microcomputer  22  and realize a reduction in production costs. Of course, the ninth embodiment can be combined with the second to eighth embodiments. 
     [Tenth Embodiment] 
     A configuration of a wireless communication module  1  according to a tenth embodiment will be now described with reference to  FIGS. 16A to 18C , with an emphasis placed on differences from those of the first to ninth embodiments. 
     (Wireless Communication Module) 
       FIGS. 16A and 16B  are schematic plan and side views of the wireless communication module  1  according to the tenth embodiment, respectively. As shown in  FIGS. 16A and 16B , a connector  26  taller than a distance L 10  between the RF board  10  and the control board  20  is disposed in a region on the control board  20  in which the RF board  10  does not overlap with the control board  20 . The connector  26  is used for external connections. This configuration makes it possible to reduce the distance L 10  between the RF board  10  and the control board  20 , which may result in compactness of the wireless communication module  1 . 
     When the connector  11  of the RF board  10  is connected to the connector  21  of the control board  20 , the RF board  10  faces the control board  20 . The RF circuit  12  is interposed between the RF board  10  and the control board  20  and the microcomputer  22  is disposed on the outer board side of the control board  20 . In addition, the antenna  13 , a connector  16  and so on are disposed on the inner board side of the RF board  10  which projects out beyond the right-edge of the control board  20  as shown in  FIGS. 16A and 16B . 
     (RF Board) 
       FIGS. 17A and 17B  are schematic plan and side views of the RF board  10  shown in  FIGS. 16A and 16B , respectively. As shown in  FIGS. 17A and 17B , the RF circuit  12  is covered by the metal shield plate  120 . Projections  14   a  to  14   d  are respectively formed in four corners of the top of the shield plate  120  which faces the control board  20 , and a projection  14   e  is formed in a central portion of one edge of a quadrangle defined by the four corners of the shield plate  120 . In addition to the projections  14   a  to  14   d  formed in the four corners, the projection  14   e  is formed in the central portion of one of its edges. This additional projection  14   e  can prevent the shield plate  120  from being mounted in a wrong direction. 
     In addition, as shown in  FIGS. 17A and 17B , the antenna  13  may be disposed in a region on the RF board  10  in which the RF board  10  does not overlap with the control board  20 . Since the shield plate  120  is electrically connected to the ground of the RF board  10 , a radio wave transmitted/received by the antenna  13  may interfere with and be absorbed into the shield plate  120  if the antenna  13  becomes too close to the shield plate  120 . 
     To avoid this problem, the shield plate  120  can be disposed at a distance L 11  from the antenna  13 , which is larger than ¼ of a wavelength (λ) of the radio wave transmitted/received by the antenna  13 . For example, for a frequency band of 920 MHz, λ/4 is about 0.75 cm and, therefore, the distance L 11  between the antenna  13  and the shield plate  120  may be set to be slightly larger than 0.75 cm (e.g., to be about 1 cm). This can prevent the radio wave transmitted/received by the antenna  13  from interfering with and being absorbed into the shield plate  120 . 
     It is to be understood that electronic parts such the connector  16  and so on may be mounted above the antenna  13 , as shown in  FIG. 17A . In addition, a space for the antenna  13  may be reduced by bending the antenna  13  or attaching coils C 1  to C 3  externally. 
     (Control Board) 
       FIGS. 18A to 18C  are a schematic plan, front and side views of the control board  20  shown in  FIGS. 16A and 16B , respectively. As shown in  FIGS. 18A to 18C , the connector  26  includes eight pins P 1  to P 8 , i.e., a VDD pin P 1 , a TXD pin P 2 , a RXD pin P 3 , a RTS pin P 4 , a CTS pin P 5 , a GPIO pin P 6 , a GPIO pin P 7  and a GND pin P 8 , arranged in this order. The VDD pin P 1  is a power source voltage input pin, the TXD pin P 2  is an asynchronous data output pin, the RXD pin P 3  is an asynchronous data input pin, the RTS pin P 4  is a RTS (Ready To Send) control output pin, the CTS pin P 5  is a CTS (Clear To Send) control input pin, the GPIO pins P 6  and P 7  are user-settable input and output pins, respectively, and the GND pin P 8  is a ground pin. These  8  pins P 1  to P 8  are arranged on the same plane in parallel to a board side  20   a  of the control board  20 , as shown in  FIG. 18B . This can limit the height L 12  of the connector  26 , thereby making the wireless communication module  1  compact. Since these input and output pins are arranged in an alternating manner, safety is guaranteed without unpredictable current flowing even if adjacent pins are circuit-shorted. 
     As described above, in the wireless communication module  1  according to the tenth embodiment, the connector  26  taller than the distance L 10  between the RF board  10  and the control board  20  is disposed in the region on the control board  20  in which the RF board  10  does not overlap with the control board  20 . This configuration makes it possible to reduce the distance L 10  between the RF board  10  and the control board  20 , which may result in compactness of the wireless communication module  1 . 
     In addition, as described above, the connector  26  includes the eight pins P 1  to P 8 , i.e., the VDD pin P 1 , the TXD pin P 2 , the RXD pin P 3 , the RTS pin P 4 , the CTS pin P 5 , the GPIO pin P 6 , the GPIO pin P 7  and the GND pin P 8 , arranged in this order. These 8 pins P 1  to P 8  are arranged on the same plane in parallel to the board side  20   a  of the control board  20 . This can limit the height L 12  of the connector  26 , thereby making the wireless communication module  1  compact. 
     In addition, as described above, the projections  14   a  to  14   e  are respectively formed in the four corners of the top of the shield plate  120  which faces the control board  20 , and the central portion of one edge of a quadrangle defined by the four corners. This can prevent the shield plate  120  from being mounted in a wrong direction. 
     In addition, as described above, the shield plate  120  is disposed at a distance L 11  from the antenna  13 , which is larger than ¼ of the wavelength (λ) of the radio wave transmitted/received by the antenna  13 . This can prevent the radio wave transmitted/received by the antenna  13  from interfering with and being absorbed into the shield plate  120 , which may prevent sensitivity of the antenna  13  from being deteriorated. 
     As apparent from the above description, the present disclosure can provide a wireless communication module  1 , an LED lighting device, a solar photovoltaic system, a self-start system and a detection device which are capable of achieving compactness while integrating the RF circuit  12  with the microcomputer  22  and realizing reduction in production costs. 
     (Other Embodiments) 
     While the present disclosure has been described by way of the first to tenth embodiments, it should be understood that the description and the drawings constituting a part of the present disclosure are only illustrative. It is apparent to those skilled in the art that the embodiments may be modified, altered, changed and operated in various different ways when reading from the detailed description and the drawings. 
     Thus, the present disclosure encompasses other different embodiments which are not described herein. For example, while it has been illustrated in  FIGS. 1A to 1C  and so on that the RF board  10  overlaps entirely with the control board  20 , the RF board  10  may overlap at least partially with the control board  20 . 
     INDUSTRIIAL APPLICABILITY 
     The wireless communication module according to the present disclosure can be applied to LED lighting devices, solar photovoltaic systems, self-start systems, detection devices and other devices and systems. 
     The present disclosure can provide a wireless communication module, an LED lighting device, a solar photovoltaic system, a self-start system and a detection device which are capable of achieving compactness while integrating an RF circuit with a microcomputer and realizing reduction in production costs. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosures. Indeed, the novel methods and apparatuses described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.