JP2011108719A - High frequency device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tuner of good productivity wherein preparation and assembling of a frame, a shield cover, or the like, are not required for shielding. <P>SOLUTION: A high frequency device includes a metal fixture 13 mounted on a circuit board 12 which is open in the vertical direction, a high frequency connector 3 fixed to the metal fixture 13, and a high frequency module 15 attached to the circuit board 12 and to which a signal input to the high frequency connector 3 is input, wherein the top surface and the side of the high frequency module 15 are covered with a metal shield film 34, the metal fixture 13 is formed to cover the signal terminal 3a of the high frequency connector 3, and the metal fixture 13 and the metal shield film 34 are connected to the ground of the circuit board 12. Consequently, the high frequency module 15 is shielded independently and an input terminal 15a and a signal terminal 3a most vulnerable to disturbance can also be shielded firmly. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high-frequency device that processes a high-frequency signal input to a high-frequency connector.

  Hereinafter, a conventional tuner (used as an example of a high-frequency device) will be described with reference to the drawings. FIG. 5A is a top view of a conventional tuner 1 and FIG. 5B is a cross-sectional view thereof. 5 (a) and 5 (b), the conventional tuner 1 has a high frequency connector 3 fixed to a metal frame 2 having an opening in the vertical direction, and the circuit board 4 is fitted in the frame 2. Combined. The electronic component 5 is directly mounted on the circuit board 4 to form a high frequency circuit. The tuner 1 includes an input filter unit that removes signals other than the received frequency, a frequency conversion unit that converts a received high-frequency signal into an IF signal, an IF circuit that processes an IF signal output from the frequency conversion unit, and the like. Includes circuit blocks.

  These circuit blocks are partitioned by a partition plate 6 to prevent signal interference between the circuit blocks. Specifically, the partition plate 6 is integrally connected to the frame 2 by a connecting portion, and the partition plate 6 and the ground of the circuit board 4 are connected to each other by solder or the like, thereby shielding the circuit block between the circuit blocks. Is done.

  Furthermore, the high frequency circuit is shielded by attaching a metal shield cover 7 so as to cover the upper and lower openings of the frame 2.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP-A-6-284024

  However, in a conventional tuner, a shield cover is provided to prepare a frame 2 in which a partition plate 6 having a very complicated shape is integrally formed to shield a high-frequency circuit, or to cover an opening of the frame 2. 7 and the like are necessary, and there is a problem that productivity is very poor.

  SUMMARY OF THE INVENTION The present invention solves this problem and aims to provide a high-frequency device with good productivity.

  In order to achieve this object, a circuit board opened in the vertical direction, a fixture mounted on the circuit board, a high-frequency connector fixed to the fixture and supplied with a high-frequency signal, and the high-frequency connector A high-frequency module mounted on the circuit board and at least an output terminal connected to the output of the high-frequency module and mounted on the circuit board. The top and side surfaces of the fixing device are covered with a metal shield member, and at least the surface of the fixture has conductivity, and the fixture is formed so as to cover the signal terminal of the high-frequency connector, and the fixing Both the tool and the shield member are connected to the ground of the circuit board. As a result, the intended purpose can be achieved.

  As described above, according to the present invention, the circuit board opened in the vertical direction, the fixture mounted on the circuit board, the high-frequency connector fixed to the fixture and supplied with a high-frequency signal, A signal input to the high-frequency connector is input, a high-frequency module mounted on the circuit board, and at least connected to an output of the high-frequency module and an output terminal mounted on the circuit board, The top and side surfaces of the high-frequency module are covered with a shield member, and at least the surface of the fixture has conductivity, and the fixture is formed so as to cover the signal terminal of the high-frequency connector, and the fixing Both the tool and the shield member are high-frequency devices connected to the ground of the circuit board.

  As a result, the high-frequency module is shielded alone, and the signal terminal of the high-frequency connector is also shielded by the fixture, and these are connected to the ground of the circuit board, so that the entire circuit board is covered with a frame or shield cover. There is no need. Therefore, it is not necessary to prepare and attach a frame body, a shield cover, etc., and a high-frequency device with very good productivity can be realized.

  Furthermore, since the high-frequency connector is fixed to the fixture, it is difficult for the high-frequency connector to be detached even if a force is applied when a cable or the like is attached to or detached from the connector.

(A) Sectional view of tuner in the present embodiment, (b) Top view of the tuner Same as above, enlarged sectional view of the main part of the tuner Sectional view of the tuner in the second example Top view of the tuner in the third example (A) Top view of a conventional tuner, (b) Same as above, sectional view

(Embodiment 1)
Hereinafter, tuner 11 (used as an example of a high-frequency device) in the present embodiment will be described with reference to the drawings. FIG. 1A is a cross-sectional view of a tuner according to the present embodiment, and FIG. 1B is a top view of the tuner. FIG. 2 is a cross-sectional view of a high-frequency module used in the tuner. In FIG. 1A, FIG. 1B, and FIG. 2, the same reference numerals are used for the same components as those in FIG. 5, and the description thereof is simplified. 1A and 1B, the tuner 11 in this embodiment is used as an example of the circuit board 12, the fixture 13, the high-frequency connector 3, the high-frequency module 15, and the input / output connector 16 (an output terminal). ).

  The circuit board 12 in the present embodiment is a single-sided board with a wiring pattern formed on the upper surface side, and its vertical direction and side are open (not covered with the frame 2 or the shield cover 7 as in the prior art). ). On the circuit board 12, a fixture 13, a signal terminal 3a of the high frequency connector 3, a high frequency module 15, an input / output connector 16 (used as an example of an output terminal), and the like are mounted. Here, the fixture 13, the signal terminal 3a, the high frequency module 15 and the input / output connector 16 are connected to a wiring pattern formed on the circuit board 12 by solder or the like. In the present embodiment, since a single-sided board is used for the circuit board 12, a very inexpensive tuner 11 can be obtained. The circuit board 12 may be a double-sided board or a multilayer board. In that case, since the wiring area can be reduced, a small tuner 11 can be realized.

  The fixture 13 is attached with the high frequency connector 3 to which a high frequency signal is input, and is formed by bending a metal thin plate. That is, the fixture 13 is formed with a top surface and four side surfaces erected downward from the peripheral portion of the top surface, and has a shape having an opening only on the lower side. The fixture 13 is mounted so that the opening side faces the circuit board 12. In a region surrounded by the fixture 13, a wiring for supplying the high frequency signal input to the signal terminal 3a to the input terminal 15a of the high frequency module 15 is formed. Here, the region surrounded by the fixture 13 is inserted between the signal terminal 3a and the input terminal 15a, such as a distribution circuit (used as an example of an input circuit) for distributing the input high-frequency signal. Including a high-frequency circuit. In the present embodiment, the distribution circuit is formed by the electronic component 17 mounted on the upper surface of the circuit board 12. The electronic components 17 and wirings that form these distribution circuits are surrounded by a fixture 13.

  Here, the lower end (opening) of the fixture 13 is connected to the circuit board 12 by solder or the like. As a result, the fixture 13 is mechanically fixed to the circuit board 12 and the ground (outer shell portion) of the high-frequency connector 3 and the ground pattern formed on the circuit board 12 are electrically connected. Here, since the fixture 13 is made of metal, the surface thereof is conductive. By doing so, the signal terminal 3a of the high-frequency connector 3 is surrounded (covered) by the fixture 13. Therefore, unnecessary high-frequency signals (so-called interference waves) can be prevented from jumping into the signal terminal 3a and the distribution circuit.

  In the present embodiment, the high frequency connector 3 is a so-called F-type plug, and a high frequency signal received by a TV broadcast receiving antenna or the like is supplied via a cable. For this purpose, a high-frequency plug is attached to the end of the cable, and the plug and the high-frequency connector 3 are fitted and connected, whereby a high-frequency signal received by the antenna is supplied to the tuner 11. It should be noted that stress is applied to the high-frequency connector 3 when the plug is detached. Therefore, the high-frequency connector 3 is securely fixed to the fixing tool 13 by caulking or the like, and the fixing tool 13 is fixed to the circuit board 12. This makes it difficult for the high-frequency connector 3 to come off even if stress is applied when the plug is attached or detached.

  In the present embodiment, the high frequency connector 3 is fixed to the top surface of the fixing tool 13, but it may be fixed to the side surface. Moreover, although the high frequency connector 3 is fixing the outer shell part of the high frequency connector 3 with respect to the fixing tool 13 by caulking etc., you may fix this with solder etc.

  In the present embodiment, the signal terminal 3 a of the high-frequency connector 3 and the input terminal 15 a of the high-frequency module 15 are connected via a connection pattern formed on the upper surface of the circuit board 12 and input to the high-frequency connector 3. A signal is supplied to the high-frequency module 15. When a double-sided board is used as the circuit board 12, a connection pattern between the signal terminal 3a and the input terminal 15a is wired on the upper surface, and a ground pattern is formed on the back side of the wiring pattern. Alternatively, when a multilayer board is used for the circuit board 12, a connection pattern between the signal terminal 3a and the input terminal 15a may be wired on the inner layer, and a ground pattern may be wired above and below the wiring pattern. As a result, the tuner 11 having a stable reception performance can be realized with little leakage of high frequency signals.

  The input / output connector 16 is connected to a power supply terminal and an output terminal of the high-frequency module 15 via a wiring pattern provided on the circuit board 12.

  Next, the high frequency module 15 mounted on the circuit board 12 will be described in detail with reference to the drawings. FIG. 2 is an enlarged cross-sectional view of a main part of the tuner 11 in a state where the high-frequency module 15 according to the present embodiment is mounted on the circuit board 12. In FIG. 2, the high-frequency module 15 includes a wiring board 31, an electronic component 32, a resin portion 33, a metal shield film 34 (used as an example of a shield member), and connection pads 35.

  In the present embodiment, the wiring board 31 is a multilayer board, and one of the inner layers is a ground layer 31a. A connection land on which the electronic component 32 is mounted is formed on the upper surface of the wiring board 31. On the connection land, the electronic component 32 is connected and fixed by solder, and a high frequency circuit is formed on the wiring board 31. On the other hand, a plurality of connection pads 35 are formed on the lower surface of the wiring board 31 in order to connect to the circuit board 12. In the present embodiment, the leftmost connection pad 35 is used as the input terminal 15 a of the high-frequency module 15. Here, in the present embodiment, the high-frequency circuit formed on the wiring board 31 converts the signal to an input filter unit that removes signals other than the received frequency or the received high-frequency signal IF signal (intermediate frequency signal). It includes circuit blocks such as a frequency converter and an IF circuit (an intermediate frequency filter and an intermediate frequency amplifier) that processes the IF signal output from the frequency converter.

  A part of the frequency conversion unit, the input filter, and the like are formed on a semiconductor and mounted on the wiring board 31 by a method such as flip chip mounting. Here, in such a semiconductor, an RC filter or the like is generally used. Therefore, it is presumed that interference is less likely to occur without providing a partition between circuit blocks.

  Next, the resin portion 33 is formed on the upper surface side of the wiring substrate 31, and the electronic component 32 is embedded therein. In the present embodiment, the side surface of the resin portion 33 and the side surface of the wiring substrate 31 are positioned on the same straight line. A metal shield film 34 is formed on the side surfaces (side surfaces of the high frequency module 15) of the resin portion 33 and the wiring substrate 31 and the upper surface of the resin portion 33 (the top surface of the high frequency module 15). Since the metal shield film 34 is formed up to the lower end portion on the side surface of the wiring substrate 31, the high-frequency circuit can be reliably shielded. Here, the ground layer 31 a is exposed on the side surface of the wiring substrate 31 and connected to the metal shield film 34. As a result, the metal shield film 34 is connected to the ground terminal 38 on the lower surface of the high-frequency module 15 via the inner ground layer 31a. In the present embodiment, the rightmost connection pad 35 is used as the ground terminal 38 of the high-frequency module 15.

  Here, the metal shield film 34 in the present embodiment is formed by sputtering. Therefore, a very dense film can be formed and a very good shielding property can be realized. The metal shield film 34 may be formed by metal plating, conductive paste, or the like. When a film is formed by metal plating, a thick film can be formed, so that the resin portion 33 can be hardly exposed due to scratches or the like. On the other hand, when the conductive paste is used, the productivity is much better than that of sputtering, so that an inexpensive tuner 11 can be realized.

  In the present embodiment, the high-frequency module 15 is mounted on the same side of the circuit board 12 as the fixture 13. For this purpose, mounting lands 37 are formed on the circuit board 12 at positions corresponding to the connection pads 35, and the connection pads 35 and the mounting lands 37 are connected via the solder 36. As a result, the circuit board 12 and the high frequency module 15 are connected, the signal terminal 3a and the input terminal 15a, the data input terminal of the high frequency module 15, the output terminal of the IF frequency signal, the power supply terminal and the input / output connector 16, and the high frequency module 15 The ground terminal 38 and the metal shield film 34 and the ground of the circuit board 12 are connected to each other. As a result, the top and side surfaces of the high-frequency module 15 are covered with the metal shield film 34, and the metal shield film 34 is connected to the ground of the circuit board 12, so that the high-frequency module can be shielded firmly. it can.

  As described above, the high frequency circuit of the high frequency module 15 is shielded by the metal shield film 34 formed on the entire top and side surfaces of the high frequency module 15, and the signal terminal 3 a of the high frequency connector 3 is shielded by the fixture 13. However, since the tuner 11 in the present embodiment does not use the frame body 2 or the shield cover 7, it is important to shield the distribution circuit and wiring between the signal terminal 3 a and the input terminal 15 a without fail. Therefore, in the tuner 11 according to the present embodiment, the input terminal 15 a of the high-frequency module 15 is disposed at a position where it is covered with the fixture 13. Of course, in this case, all the wiring and the distribution circuit between the input terminal 15a and the signal terminal 3a are also covered with the fixture 13. Thereby, it is possible to obtain a good shielding property without using the frame body 2 or the shield cover 7 that covers the entire circuit board 12, and an interference signal enters between the signal terminal 3a and the input terminal 15a. Etc. can be reduced. Therefore, it is not necessary to prepare the frame body 2 and the shield cover 7 or to assemble them, and the tuner 11 with good productivity can be realized.

  In the present embodiment, the circuit board 12 is a single-sided board, but a double-sided board may be used. In this case, the wiring between the signal terminal 3a and the input terminal 15a and the electronic components forming the distribution circuit are mounted on the upper surface, and the lower surface of the position corresponding to the wiring and the electronic components is grounded. You can get a good shield. The circuit board 12 may be a multilayer board. In this case, the wiring between the signal terminal 3a and the input terminal 15a is wired in the inner layer as much as possible, and the electronic components forming the circuit are mounted on the upper surface of the circuit board 12. Then, as in the case of both sides, the shield can be obtained more firmly by setting the lower surface of the position corresponding to them to the ground.

  In the above configuration, since the input terminal 15 a is disposed so as to be covered with the fixture 13, a part of the top surface of the high-frequency module 15 is covered with the fixture 13. That is, the side surface excluding at least one of the four side surfaces of the fixture 13 is disposed above the high-frequency module 15. At this time, a gap may be provided between the side surface and the top surface of the high-frequency module 15. Accordingly, even if a load is applied to the high-frequency connector 3 due to attachment or detachment or the like, it is difficult to apply a load to the high-frequency module 15, so that the connection between the high-frequency module 15 and the circuit board 12 can be stably maintained for a long time.

  The circuit board 12 in the present embodiment is a single-sided board, but a better shield can be obtained if a multilayer board is used. For this purpose, the signal terminal 3a and the input terminal 15a may be wired in the inner layer. Furthermore, if the connection pattern between the signal terminal 3a and the input terminal 15a is surrounded by a ground pattern, a better shielding property can be obtained.

  Here, it is desirable to form a ground pattern around the input terminal 15a itself and the mounting land 37 corresponding to the input terminal 15a in the wiring board 31 and the circuit board 12. Thereby, the disturbance to the input terminal 15a can be reduced. Furthermore, it is further preferable to provide the connection pads 35 and the mounting lands 37 on the surrounding ground patterns and connect them with solder or the like. This further reduces interference with the input terminal 15a.

  Further, in the circuit board 12, a ground pattern is preferably wired at a position corresponding to the peripheral edge of the high frequency module 15 except for a signal wiring portion to the high frequency module 15. In the high-frequency module 15, since the metal shield film 34 is formed up to the lower end of the side surface of the wiring substrate 31 by sputtering, the gap between the ground of the circuit board 12 and the metal shield film 34 can be reduced. Therefore, it can shield firmly. However, in this case, it is desirable that the size of the gap between the lower surface of the high-frequency module 15 and the upper surface of the circuit board 12 be at least 1/4 of the wavelength length with respect to the highest frequency of the received frequency. Furthermore, if the distance between the ground patterns separated via the signal wiring is set to a dimension equal to or smaller than ¼ of the above wavelength, a better shield can be obtained.

  Further, if a ground pattern is provided on the peripheral edge of the lower surface of the high-frequency module 15, the periphery of the high-frequency circuit is completely covered with the ground, so that the high-frequency circuit can be firmly shielded in this case as well.

  In order to obtain better shielding properties, a mounting land 37 connected to the ground is formed along the outer periphery of the high-frequency module 15 on the circuit board 12, and the metal shield film 34 and the mounting land 37 are connected to each other. It is desirable to solder directly between them. In that case, if a multilayer substrate is used for the circuit board 12, wiring of signals or the like to the high frequency module 15 can be routed through the inner layer, so that the metal shield film 34 is formed on the circuit board 12 around the entire periphery of the high frequency module 15. It can be connected to the ground and can be shielded more reliably.

  FIG. 3 is a cross-sectional view of a tuner in another example. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is simplified. In FIG. 3, the circuit board 12 uses a double-sided board or a multilayer board. In this example, the fixture 13 is attached to the lower surface side of the circuit board 12. Also in this example, the high frequency module 15 is mounted at a position corresponding to the area where the input terminal 15 a is surrounded by the fixture 13. Thereby, the signal terminal 3a to the input terminal 15a can be shielded firmly. In this case, the mounting land 37 corresponding to the input terminal 15 a is led out to the lower surface of the circuit board 12 by a through hole or the like in the region surrounded by the fixture 13.

  Although only one high-frequency module 15 is mounted on the circuit board 12 in the present embodiment, two or more high-frequency modules may be mounted. However, other high-frequency modules (not shown) are also used in which the top and side surfaces are covered with the metal shield film 34. Thereby, since both the high frequency module 15 and the other high frequency modules can be shielded firmly, interference between them is less likely to occur. For example, if a demodulation circuit or the like to which the IF frequency signal output from the high frequency module 15 is supplied in another high frequency module, a high frequency digital signal (such as a clock) in the demodulation circuit is transferred to a circuit in the high frequency module 15. It is difficult to cause interference.

  FIG. 4 is a top view of the tuner 11 in the third example. In FIG. 4, the same reference numerals are used for the same components as those in FIG. 1, and the description thereof is simplified. FIG. 4 shows a case where the same high-frequency module 15 as that of the high-frequency module 15 is used. The two high-frequency modules 15 perform so-called diversity reception. Thereby, the interference between the high frequency modules 15 can be reduced. In this case, the fixture 13 needs to be sized so as to cover both the input terminals 15a. For this purpose, the width 51 of the fixture 13 is made larger than the distance 52 between both the input terminals 15a.

  The high-frequency device according to the present invention has an effect that the productivity is good, and is useful when used, for example, in a tuner that receives a TV broadcast.

DESCRIPTION OF SYMBOLS 3 High frequency connector 3a Signal terminal 12 Circuit board 13 Fixing tool 15 High frequency module 16 Input / output connector 34 Metal shield film

Claims (11)

A circuit board that is open in the vertical direction, a fixture mounted on the circuit board, a high-frequency connector that is fixed to the fixture and supplied with a high-frequency signal, and a signal that is input to the high-frequency connector is input And at least one high-frequency module mounted on the circuit board, and an output terminal connected to the output of the high-frequency module and mounted on the circuit board, the top surface of the high-frequency module And the side surface is covered with a metal shield member, and at least the surface of the fixture has conductivity, and the fixture is formed so as to cover the signal terminal of the high-frequency connector, and the fixture and the side A high-frequency device connected to a ground of the circuit board together with a shield member. The high-frequency device according to claim 1, wherein the fixture is made of metal. The high-frequency device according to claim 2, wherein the high-frequency module is disposed in a region where at least an input terminal of the high-frequency module is covered with a fixture on the circuit board. The high-frequency device according to claim 3, wherein the connection pattern for connecting between the signal terminal of the connector and the input terminal of the high-frequency module is wired in a region covered with a fixture on the circuit board. The high frequency device according to claim 4, wherein a ground pattern is formed on a back surface of the wiring pattern. The high-frequency device according to claim 3, wherein the high-frequency module and the fixture are mounted on the same surface side of the circuit board, and only a part of the high-frequency module is covered by the fixture in the high-frequency module. The fixture has a top surface, a first side surface provided upright at one peripheral end of the top surface, and the same as the first side surface at the remaining three peripheral end portions of the top surface. A second side plate erected in the direction, and the input terminal is mounted so as to be disposed in a region surrounded by the top plate and the first and second side plates, and at least the second side plate is mounted. The high-frequency device according to claim 6, wherein any one of the side surfaces of the module is disposed at a position above the module top surface. The high frequency apparatus according to claim 7, wherein a gap is formed between a second side plate provided above the high frequency module and a top surface of the high frequency module. The electronic component is mounted on the circuit board, an input circuit to be inserted between at least the connector and the high-frequency module is formed by the electronic component, and the electronic component is covered with a fixture. High frequency equipment. The high-frequency device according to claim 9, wherein a ground pattern is formed on a back surface of the electronic component. A high frequency apparatus in which a module to which an output of a high frequency module is supplied is mounted on a circuit board, and a top surface and a side surface of the module are covered with a shield member.

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