High frequency tuner module

Disclosed is a high frequency wave tuner module including a circuit board having an approximately rectangular shape, which is made of ceramic material and a shield cover to shield an interfering wave by covering a circuit part mounted on a board surface of the circuit board, and a position of the shield cover in a height direction with respect to the board surface is determined by fixing the shield cover to the board surface at four corner positions of the circuit board, and a position of the shield cover in a board surface direction with respect to the circuit board is determined by engaging at least two side walls of the shield cover which extend in a thickness direction of the circuit board, with end surfaces of the circuit board, which correspond to the two side walls.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high frequency wave tuner module, and particularly to a high frequency wave tuner module which is provided with a shield cover to shield the interfering wave from outside.

2. Description of Related Art

In high frequency wave tuner module for receiving the signal of high frequency band such as the television tuner for the terrestrial digital broadcasting, the tuner for wireless LAN or a tuner for satellite radio or the like which is in used in the U.S., the module is structure by disposing the wiring patters such as the signal wire, the GND wire and the like and the circuit parts on both surfaces or on one surface of the single layer circuit board. Further, in recent years, a multiple-layer board which is formed by layering a plurality of boards is used as the circuit board for downsizing and thinning of the tuner module and improvement of the component mounting density of the tuner module (for example, JP5-327230A).

Moreover, in many cases, a shield cover for covering the board surface of the circuit board to shield the interfering wave from outside is provided in such circuit boards (for example, JP2006-101467A). Further, the GND of the circuit board is assured by connecting the shield cover with the GND of the board by soldering or the like.

In the manufacturing of the high frequency wave tuner module, the shield cover is attached to the circuit board as described in the above mentioned JP2006-101467A. Here, for example, the notches102are provided on the circuit board101as shown inFIG. 4Aand the convex portions105are provided on the side walls104of the shield cover103at the positions corresponding to the above mentioned notches102as shown inFIG. 4Bin order to correctly decide the position of the shield cover with respect to the circuit board.

As shown inFIG. 5, the position of the shield cover103is determined with respect to the circuit board101by inserting the convex portions105of the shield cover103in the notches102of the circuit board101, and the four corners of the shield cover103are connected and fixed to the circuit board101by soldering or the like in a state where the four corners of the shield cover103are in contact with the circuit board101to form the high frequency wave tuner module100.

The circuit board is usually manufactured by cutting one large board. When the notches are to be provided on the circuit board as described above, conventionally, the holes107which become the above mentioned notches102and the holes108which corresponds to the cut off portions of the four corners of the circuit board are perforated in the one large board106in advance as shown inFIG. 6, and the circuit boards having the notches are manufactured by cutting the board. Further, there is a case where the notches are formed after the circuit boards are cut out from the one large board.

However, there is a case where the low-temperature conferred ceramic (LTCC) having alumina as the base material is used for the single layer or the multiple-layer circuit board which is used for the high frequency wave tuner module. The ceramic material such as the low-temperature conferred ceramic is usually hard and the process of perforating the holes107and108in the board106and the process of forming the notches by scraping the circuit board as shown inFIG. 6are not necessarily easy processes. The process of perforating a hole is easy before calcining because the material is soft. However, an accuracy of the size after calcining is hard to acquire. Further, the number of the processes increases because the process such as perforating holes in a large board or the like is needed, and the improvement of the productivity of the circuit board is prevented.

Moreover, when the convex portions of the shield cover are inserted in the notches of the circuit board, the circuit parts cannot be mounted on the portion101aoutside of the side walls104of the shield cover103within the circuit board101as shown in the high frequency wave tuner module100ofFIG. 5, and the area on the circuit board101in which the circuit parts can be mounted is reduced. In contrary, when attempting to assure the area for mounting the circuit parts, the circuit board101needs to be made larger for the portion of the above mentioned outside portion101a. Therefore, there is a problem that the downsizing of the high frequency wave tuner module is prevented.

SUMMARY OF THE INVENTION

In view of the above problems, a main object of the present invention is to provide a high frequency wave tuner module which can assure the area on the circuit board for mounting the circuit parts and which can improve the productivity.

According to a first aspect of the present invention, there is provided a high frequency wave tuner module comprising a circuit board having an approximately rectangular shape, which is made of ceramic material and a shield cover to shield an interfering wave by covering a circuit part mounted on a board surface of the circuit board, and a position of the shield cover in a height direction with respect to the board surface is determined by fixing the shield cover to the board surface at four corner positions of the circuit board, and a position of the shield cover in a board surface direction with respect to the circuit board is determined by engaging at least two side walls of the shield cover which extend in a thickness direction of the circuit board, with end surfaces of the circuit board, which correspond to the two side walls.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Hereinafter, the embodiment of the high frequency wave tuner module according to the invention will be described with reference to the drawings.

In the embodiment, a description will be given for a case where the circuit board of the high frequency wave tuner module is formed in a single layer. However, the present invention is not limited to the case where the circuit board is single layer, and the same description applies for the case where the circuit board is a multi-layer board.

As shown in the perspective view ofFIG. 1Aand in the side view ofFIG. 1B, the high frequency wave tuner module1of the embodiment comprises a circuit boar2and a shield cover3. Here, in the embodiment, the input and output of the signal to and from the high frequency wave tuner module1is carries out via external terminal electrodes (omitted from the drawing) which are formed on one surface of the circuit boar2.

The circuit board2is formed with low-temperature conferred ceramic member, and is formed in a square form in the embodiment. Further, various types of circuit parts4and wiring5such as a signal wire, the GND wire and the like are mounted on the board surface2aof the circuit board2, that is on the surface which is the other side of the surface on which the above mentioned external terminal electrodes are provided.

Moreover, in the embodiment, the notches shown in the conventional example ofFIGS. 4A and 5are not formed on the end surface2bof the circuit board2, and each of the four end surfaces2bis formed in an elongated planar shape so as to be orthogonal to the board surface2a.

The shield cover3is formed with metallic member, and shields the interfering wave from outside by covering the circuit parts4and the like which are mounted on the board surface2aof the circuit board2. In the embodiment, the shield cover3is formed by a metallic thin plate being bent in an approximately case shape, and the base surface3aof the shield cover3is disposed so as to be parallel to the board surface2aof the circuit board2.

Further, the tip portions of the four side walls3b(hereinafter, called the corner part side walls3b) of the shield cover3contact the four corner-portions of the rectangular shaped circuit board2. The position of the shield cover3in the high direction with respect to the board surface2aof the circuit board2is determined by the four corner part side walls3bbeing fixed to the circuit board2at the above mentioned positions. That is, the length of the corner part side walls3bdetermines the height of the base surface3aof the shield cover3with respect to the board surface2aof the circuit board2.

In the embodiment, the GND wires (omitted from the drawing) are arranged at the four corner portions of the circuit board2. By the corner part side walls3bof the shield cover3being fixed to the GND wires by soldering6, the position of the shield cover3is determined and the shield cover3is electrically connected with the GND of the circuit board2. Here, the shield cover3and the GND can be connected and be fixed by conductive resin or the like instead of the soldering6.

Moreover, the four side walls3c(hereinafter, called the edge part side walls3c) of the shield cover3which are provided so as to correspond to the end surfaces2bof the square shaped circuit board2, respectively, are provided so as to extend in the sides of the end surfaces2bof the circuit board2exceeding the board surface2aof the circuit board2, that is, so as to extend in the width direction of the circuit board2.

That is to say, in the embodiment, the length of the edge part side walls3cof the shield cover3from the base surface3ais formed so as to be longer than the length of the corner part side walls3bfrom the base surface3a. The length of the edge part side walls3care adjusted within the range so that the tip portions of the edge part side walls3cdo not extend in the lower direction exceeding the back surface of the circuit board2, that is the surface on which the external terminal electrodes are provided in the embodiment as shown inFIGS. 1A and 1Bin a state where the shield cover3is fixed to the circuit board2via the corner part side walls3b.

The four edge part side walls3cof the shield cover3contact the four end surfaces2bof the circuit board2from the side, respectively, and each of the edge part side walls3cengages with the corresponding end surface2bof the circuit board2so as to fit to determined the position of the shield cover3in the board surface direction with respect to the circuit board2.

Next, the effect of the manufacturing process of the high frequency wave tuner module1according to the embodiment will be described by showing the manufacturing process.

First, the circuit board2of the high frequency wave tuner module1is formed by cutting a large low-temperature conferred ceramic member board (omitted from the drawing). Here, the low-temperature conferred ceramic member board is merely cut in necessary shapes in the embodiment, and the operation such as perforating holes in the board or forming notches and the like on the end surfaces2bof the circuit board2which is formed by cutting the board as in the above mentioned conventional example is not carried out.

The wiring patter is formed on the board surface2aor the like of the circuit board2, and the circuit board2is completed by having the needed circuit parts4disposed and by connecting with the wiring5.

Meanwhile, the shield cover3shown inFIG. 2is formed by punching or the like from a metallic thin plate. Here, the four edge part side walls3cis formed so as to be longer than the corner part side walls3bas described above in the embodiment. Then, the shield cover3which is formed by the process described above is put over the circuit board2so as to cover the circuit parts4from the upper direction of the board surface2aof the circuit board2.

Then, the four edge part side walls3cof the shield cover3contact the four end surfaces2bof the circuit board2from the side, respectively, and are engaged with the corresponding end surfaces2bof the circuit board2so as to be fitted. In such way, the position of the shield cover3in the board surface direction with respect to the circuit board2is determined.

When the shield cover3proximate the circuit board2further more, the shield cover3reaches the point where it cannot proximate the circuit board2any more by the corner part side walls3bof the shield cover3contacting the four corner positions of the circuit board2. In such way, the position of the shield cover3in the height direction with respect to the board surface2aof the circuit board2is determined.

Then, the corner part side walls3bof the shield cover3are soldered to the GND wires which are arranged in the four corners of the circuit board2to fix the shield cover3to the circuit board2and to electrically connect the shield cover3with the GND of the circuit board2.

As described above, according to the high frequency wave tuner module1of the embodiment, there is no need to perforate the holes in the original hard ceramic member board and to form the notches on the end surfaces2bof the circuit board2in the manufacturing process of the circuit board2. Further, the shield cover3can be formed easily by punching or the like. Moreover, the position of the shield cover3in the board surface direction and in the height direction can be automatically and surely determined just by putting the shield cover3over the circuit board2.

Therefore, the high frequency wave tuner module can be manufactured very easily without increasing the number of operation processes. Thus, the productivity can be greatly improved.

Moreover, in the high frequency wave tuner module1of the embodiment, the area on the board surface2aof the circuit board2in which the circuit parts4can be mounted is all the area except for the four corners of the circuit board2as shown inFIG. 1A. Further, because even the four corners can be used as the portions in which the GND wires are provided and in which the shield cover3and the GND are being connected as described above, the entire area on the board surface2aof the circuit board2is practically the area in which the circuit parts4and the like can be mounted.

That is to say, there is no unavailing area on the circuit board2of the high frequency wave tuner module1of the embodiment, such as the portions101aoutside of the side walls in which the circuit parts cannot be mounted in the conventional high frequency wave tuner module100shown inFIG. 5. Therefore, the high frequency wave tuner module can be downsized, and at the same time the area for mounting the circuit parts4and the like on the circuit board2can be sufficiently reserved.

The high frequency wave tuner module1according to the present invention can be modified in various ways.

In the above described embodiment, the description is given for the case where the four edge part side walls3cof the shield cover3are formed so as to be longer than the corner part side walls3b. However, for example, the three edge part side walls3cA to3cC among the four edge part side walls3cA to3cD shown inFIG. 2can be formed so as to be longer than the three of the corner part side walls3b, and the remaining edge part side wall3cD can be formed in the same length as the corner part side wall3b.

In such case, when the shield cover3is fitted to the circuit board2, first, the edge part side walls3cA and3cC of the shield cover3holds the end surfaces2bof the circuit board2, and then the position of the shield cover3can be easily determined by pressing the circuit board2onto the edge part side wall3cB. Therefore, the corner part side walls3bcan be fixed to the circuit board2by soldering or the like.

Moreover, only two of the edge part side walls of the shield cover3which are orthogonal to one another, for example, the edge part side walls3cA and3cB, can be formed so as to be longer than the corner part side walls3b, and the remaining edge part side walls3cC and3cD can be formed in the same length as the corner part side walls3b.

In such case, when the shield cover3is fitted to the circuit board2, the position of the shield cover3can be easily determined by pressing the end surface2bof the circuit board2onto the edge part side walls3cA and3cB of the shield cover3which are formed so as to be longer than the corner part side walls3b. Therefore, the corner part side walls3bcan be fixed to the circuit board2by soldering or the like.

Meanwhile, when the shield cover3is formed, there is a case where a plurality of shield covers3are connected in a strip form by the connecting pieces7as shown inFIG. 3. In such case, only two of the edge part side walls3cA and3cC of the individual shield cover3which face one another are to be formed so as to be longer than the corner part side walls3b, and the remaining edge part side walls3cB and3cD are to be formed in the same length as the corner part side walls3b. Here, the circuit boards2are formed by having a plurality of the circuit boards2connected, and the circuit parts4and the like are mounted on the board surfaces2aof the circuit boards2in advance.

Then, when the plurality of shield cover3in a strip form is put over the plurality of circuit boards2from the upper direction of the plurality of circuit boards2in a strip form, the edge part side walls3cA and3cC of the shield cover3hold the end surfaces2bof the circuit boards2. Therefore, at least the shield cover3is restricted from moving in the width direction of the circuit board2which is indicated by an arrow X in the drawing, and the position of the shield cover3in the width direction X is determined.

The position of the shield cover3in the longitudinal direction of the circuit board2which is indicated by an arrow Y in the drawing is arbitrarily adjusted. Further, by cutting out the circuit boards2individually along with the connecting pieces7after all the corner part side walls3bof the shield cover3are fixed to the circuit board2by soldering or the like, the high frequency wave tuner module can be manufactured easily and efficiently.

Here, in the above described embodiment and the modification, the notches are not provided on the end surfaces2bof the circuit board2. However, the four corner portions of the circuit board2can be cut off as shown in the conventional example ofFIGS. 4 and 5within the range in which the corner part side walls3bcan be fixed to the circuit board2, and this cutting off of the corner parts is arbitrarily carried out.

According to a first aspect of the preferred embodiment of the present invention, there is provided a high frequency wave tuner module comprising a circuit board having an approximately rectangular shape, which is made of ceramic material and a shield cover to shield an interfering wave by covering a circuit part mounted on a board surface of the circuit board, and a position of the shield cover in a height direction with respect to the board surface is determined by fixing the shield cover to the board surface at four corner positions of the circuit board, and a position of the shield cover in a board surface direction with respect to the circuit board is determined by engaging at least two side walls of the shield cover which extend in a thickness direction of the circuit board, with end surfaces of the circuit board, which correspond to the two side walls.

In accordance with the first aspect of the preferred embodiment of the present invention, the shield cover is fixed to the board surface at the four corners of the circuit board, the position of the shield cover is automatically determined in the height direction with respect to the board surface by the shield cover being fixed to the board surface. Further, the position of the shield cover in the board surface direction with respect to the circuit board is determined by at least two side walls of the shield cover engaging with the end surfaces of the circuit board. Therefore, there is no need to provide notches for determining the position of the shield cover on the end surfaces of the circuit board as in the above mentioned conventional example. Thus, the process of perforating holes in the hard ceramic member board and the process of providing notches in the end surfaces of the circuit board are not needed in the manufacturing of the circuit board.

Moreover, the shield cover can be formed easily by punching or the like, and the position of the shield cover in the board surface direction and the height direction can be automatically determined just by putting the shield cover over the circuit board. Therefore, the high frequency wave tuner module can be manufactured very easily and without increasing the number of operation process. Thus, the productivity can be greatly improved.

Furthermore, in the high frequency wave tuner module according to the present invention, the area on the board surface of the circuit board in which the circuit parts can be mounted is the entire area except for the four corners of the circuit board as shown inFIG. 1A. Further, even the four corner portions are being used by having the GND wires provided there to allow the shield cover to have the electric potential of the GND level by connecting the GND wires with the shield cover. Therefore, the entire area on the board surface of the circuit board can practically be the area in which the circuit parts and the like can be mounted.

That is to say, there is no unavailing space on the circuit board of the high frequency wave tuner module of the present invention, such as the portions101aoutside the side walls in the convention high frequency wave tuner module in which the circuit parts cannot be mounted as shown inFIG. 5. Therefore, the high frequency wave tuner module can be downsized and also a sufficient area for mounting the circuit parts and the like can be assured on the circuit board.

Preferably, the position of the shield cover in the board surface direction with respect to the circuit board is determined by engaging four side walls of the shield cover which extend in the thickness direction of the circuit board, with the end surfaces of the circuit board, which correspond the four side walls.

The position of the shield cover with respect to the circuit board can be determined easily and correctly because the four side walls of the shield cover engage with the end surfaces of the circuit board so as to fit to the circuit board. Therefore, the same effect can be obtained more effectively and efficiently.

Preferably, the position of the shield cover in the board surface direction with respect to the circuit board is determined by engaging the two side walls of the shield cover orthogonal to one another which extend in the thickness direction of the circuit board, with the corresponding end surfaces of the circuit board.

The position of the shield cover can be determined easily because the position of the shield cover with respect to the circuit board can be determined by pressing the end surfaces of the circuit board onto two of the side walls of the shield cover which are orthogonal to one another. Therefore, the same effect can be obtained efficiently.

Preferably, the position of the shield cover in the board surface direction with respect to the circuit board is determined by engaging the two side walls of the shield cover facing one another which extend in the thickness direction of the circuit board, with the corresponding end surfaces of the circuit board.

For example, when the high frequency wave tuner module is formed by cutting circuit boards after the circuit boards formed by a plurality of circuit boards being continuously connected are covered with a plurality of shield covers which are continuously formed in a strip form, the position of the shield cover can be determined easily by forming the side walls of the individual shield covers facing one another which correspond to the end surface of the individual circuit boards which are continuously formed so as to be higher. Therefore, the same effect can be obtained efficiently.

Preferably, the circuit board has the approximately rectangular shape without notches formed on the end surfaces.

There is no need to carry out a process of perforating holes in the original hard ceramic member board and a process of providing notches on the end surfaces of the circuit board because the circuit board can be formed in a square shape only by merely cutting the original board. Therefore, the high frequency wave tuner module can be manufactured very easily without increasing the number of operation process. Thus, the same effect can be obtained efficiently because the productivity can be greatly improved.

The entire disclosure of Japanese Patent Application No. 2007-013471 filed on Jan. 24, 2007 including description, claims, drawings, and abstract are incorporated herein by reference in its entirety.