JPH04322498A - High-frequency apparatus - Google Patents

Abstract

PURPOSE:To provide an electronic tuner which reduces the number of components, whose thickness is made thin and which can be surface-mounted. CONSTITUTION:In a state that a metal case 4 has been placed on a printed- circuit board 3 in which a grounding pattern has been formed on its lower main face, the metal case 4 and the printedcircuit board 3 are fixed to each other by using coupling pieces 15 and 16. A plurality of circuit components are mounted on the upper main face of the printed-circuit board 3. A plurality of terminals 25 formed of a conductive film are arranged on one end edge part of the printed-circuit board 3; the circuit board is connected electrically to a board on the side of a set via the terminals 25.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to high frequency equipment, and more particularly to a structure for surface mounting such high frequency equipment.

0002

2. Description of the Related Art A typical example of high frequency equipment is an electronic tuner.

[0003] In a conventional electronic tuner, a printed circuit board on which a plurality of circuit components necessary for constructing an electronic circuit are mounted is assembled in a metal frame, and openings at both ends of the metal frame are each covered with a metal cover. It has a similar structure. The pin terminals connected to the printed circuit board are led out of the metal frame, and when mounting such an electronic tuner on the set-side board, the pin terminals are inserted into holes provided in the set-side board and soldered. be done.

0004

SUMMARY OF THE INVENTION The conventional electronic tuner described above is inherently small and can contribute to the miniaturization of electronic equipment in which such a tuner is used. However, the trend toward smaller and thinner electronic devices is
There is no end in sight, and conventional electronic tuners are no longer able to keep up with the miniaturization and thinning of electronic devices.

For example, conventional electronic tuners have a relatively large overall thickness, which may preclude their use in electronic devices that are becoming thinner.

[0006] Also, as an effective means for reducing the size and thickness of electronic devices, surface mounting of electronic components used in electronic devices is sometimes used. This technology focuses on the space occupied by pin terminals and lead wires in various electronic components.By eliminating these pin terminals and lead wires, the space required for mounting can be saved, allowing electronic devices to be made smaller and thinner. This is an attempt to make the world a better place. However, none of the conventional electronic tuners is of a type that can be surface mounted.

Furthermore, the conventional electronic tuner has a relatively large number of parts and a relatively large number of assembly steps, and therefore has the problem of high cost.

[0008] Therefore, an object of the present invention is to provide a structure for high-frequency equipment that can be surface mounted, reduce the number of parts, and be made smaller and thinner. .

[0009]

[Means for Solving the Problems] A high frequency device according to the present invention includes a printed circuit board on which a ground pattern is formed, a plurality of circuit components mounted on one main surface of the printed circuit board, and the circuit components. a metal case combined with the printed circuit board so as to electromagnetically shield the circuit board together with the ground pattern and surround the circuit components together with the printed circuit board; It is characterized by being provided with a plurality of terminals formed of conductors having shapes.

0010

[Operation] In the high frequency equipment according to the present invention, when the printed circuit board and the metal case are combined, the printed circuit board constitutes a part of the housing of such high frequency equipment. Since a ground pattern is formed on this printed circuit board, one of the conventional metal covers can be omitted. Furthermore, since a plurality of terminals made of a film-like conductor are provided at the edge of the printed circuit board that constitutes a part of the housing, conventional pin terminals can be omitted.

[0011]

Therefore, according to the present invention, it is possible to perform surface mounting using the terminals provided at the edge of the printed circuit board.

Furthermore, as described above, since some parts can be eliminated, the number of assembly steps can also be reduced.

[0013] Furthermore, since the housing of the high-frequency device is composed of a printed circuit board and a metal case, it can be made smaller and thinner, making it fully compatible with the miniaturization and thinning of electronic devices. .

[0014] Furthermore, since there is no protruding pin terminal,
Packaging of the high frequency equipment can be easily automated. Similarly, attachment to the set-side substrate using an automatic machine becomes easy, and electronic equipment including such high-frequency equipment can be manufactured at high speed and in-line.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic tuner as a representative example of high frequency equipment according to the present invention will be described below.

FIG. 1 shows a state in which an electronic tuner 1 according to an embodiment of the present invention is mounted on a set-side board 2. As shown in FIG. This electronic tuner 1 includes a printed circuit board 3 and a metal case 4, as shown in FIG.

The metal case 4 is made of a metal plate, and includes an upper wall 5 and four side walls 6, 7, 8, and 9 depending from the periphery of the upper wall 5. Shield plates 10 and 11 are integrally formed on the upper wall portion 5 by cutting a portion of a metal plate and raising it downward. The through holes 12 and 13 left in the upper wall portion 5 for forming these shield plates 10 and 11 do not become very large because the metal case 4 is made as low as possible, and therefore, normally may be left as is. however,
If you want a more complete electromagnetic shield, use through hole 1.
A conductive sticker may be attached to cover 2 and 13. Note that the shield plates 10 and 11 are attached to the metal case 4.
It may be constituted by a separate member.

The upper wall portion 5 is further provided with a plurality of adjustment holes 14 into which tools for adjustment can be inserted.

Each of the side walls 6 and 8 is provided with a plurality of locking pieces 15 for fixing the metal case 4 attached to the printed circuit board 3. Also, locking pieces 16 that perform the same function are also provided on the shield plates 10 and 11.
is provided.

A notch 17 is provided in the side wall portion 6 in order to avoid contact with a specific portion of the printed circuit board 3 (a portion where a plurality of terminals are provided). Further, the side wall portion 7 is provided with a recess 18 to facilitate identification of the orientation of the metal case 4.

The printed circuit board 3 is of a double-sided wiring type, for example, and main wiring (not shown) is provided on its upper main surface, and a plurality of circuit components 19 (FIG. 1) are surface-mounted. has been done. The printed circuit board 3 may be made of any material,
For example, resin or ceramic is used.

The lower major surface of printed circuit board 3 is shown in FIG. As shown in Figure 3, the printed circuit board 3
Most of the lower main surface of the electronic tuner 1 is covered with a ground pattern 21, except for some wiring 20 such as a power supply line, which does not interfere with the performance of the electronic tuner 1. This achieves electromagnetic shielding. Furthermore, as a printed circuit board,
If a multi-layered structure is used, it is possible to cover the entire lower main surface with a ground pattern, and in this case, the structure is completely ensured against electromagnetic shielding.

A notch 22 is provided at the peripheral edge of the printed circuit board 3 to receive the locking piece 15 described above. Also,
At the center of the printed circuit board 3, there is the aforementioned locking piece 16.
A slot 23 is provided for receiving the. Further, a notch 24 is provided at the peripheral edge of the printed circuit board 3 at a position corresponding to the recess 18 of the metal case 4 described above.

Further, at the edge of the printed circuit board 3 and at a position corresponding to the side wall 6 of the metal case 4 described above, a plurality of terminals 25 formed of a film-like conductor are positioned. A cutout 26 is provided. Such a notch 26
And the terminal 25 can be formed as follows, for example.

Referring to FIG. 4, the printed circuit board 3 is preliminarily given a large size with the intention of being cut later along a cutting line 27 shown by a dashed line. Such a printed circuit board 3 has the above-mentioned notch 26.
A through hole 28 is formed, for example, by a drill or the like, at a position corresponding to . In this state, a conductive film 29 is formed on the inner peripheral surface of the through hole 28 by, for example, electroless plating. Note that the conductive film 29 may be formed so as to extend to the peripheral edges of both end surfaces of the through hole 28, as shown in FIG. Next, when cut along cutting line 27, through hole 28 becomes notch 26, and terminal 25 is provided by conductive film 29. These terminals 2
5 is directly electrically connected to a predetermined conductive part (not shown) provided on the set-side board 2 (FIG. 1) by soldering.

In the illustrated embodiment, a plurality of terminals 2
5 are placed all along one edge of the printed circuit board 3, but alternatively they may be placed along two to four edges, or some of the terminals may be printed. It may also be placed inside the circuit board.

In fixing the printed circuit board 3 and the metal case 4 to each other, the metal case 4 is first placed on the printed circuit board 3. At this time, the locking piece 1
5 is received in the notch 22, and the locking piece 16 is inserted into the slot 2.
Accepted within 3 days. Next, the locking pieces 15 each
The locking pieces 16 are bent inward, and the locking pieces 16 are bent in either direction, so that the locking pieces 15 and 16 are brought into engagement with the lower main surface of the printed circuit board 3. This fixes the metal case 4 to the printed circuit board 3.

[0028] As a method of fixing the printed circuit board and the metal case to each other, through holes with a conductive film formed thereon are formed in the printed circuit board, and locking pieces provided on the metal case are inserted into these through holes. After that, a method of soldering or another method may be used.

The electronic tuner 1 thus obtained can be surface-mounted on the set-side substrate 2, as shown in FIG. At this time, preferably, the electronic tuner 1 is temporarily fixed to the set-side substrate 2 with an adhesive, and then soldered by a reflow method. In soldering by such a reflow method, as shown in Fig. 5,
While the terminal 25 is soldered with solder 30, the locking piece 15 provided on the metal case 4 is also soldered with solder 31, and further, although not shown, the shield plate 10
It is also preferable that the locking pieces 16 provided at and 11 are also soldered. In particular, in such soldering, the presence of the locking pieces 15 and 16 prevents the printed circuit board 3
Since a gap with a size corresponding to the thickness (for example, 0.2 mm) of the metal plate constituting the metal case 4 is formed between the set side board 2 and the set side board 2, the fluidity of the solders 30, 31, etc. is improved. , the reliability of soldering is increased.

FIG. 6 shows a combination of a printed circuit board 3a and a metal case 4a in another embodiment of the invention. Side wall portion 32 provided in metal case 4a
On the shield plate 33, in addition to locking pieces 34 and 35 corresponding to the locking pieces 15 and 16 described above, earth claws 36 and 37 are formed by cutting and bending. These ground claws 36 and 37 elastically contact a ground pattern (not shown) formed on the upper main surface of the printed circuit board 3a. Therefore, as shown by the broken lines, when the locking pieces 34 and 35 are bent, the printed circuit board 3a and the metal case 4a can be fixed to each other without wobbling.

FIG. 7 shows a schematic plan view of a printed circuit board 3b included in yet another embodiment of the invention. In the embodiment described above, as shown in FIGS. 2 and 3, the notch 24 was provided to facilitate identification of the orientation of the printed circuit board 3, but in this embodiment, the cutout 24 A chamfer 38 is formed at each corner. Although not shown, this printed circuit board 3
A metal case that conforms to b also has a corresponding shape.

Further, as shown in FIG. 2, for example, in order to eliminate angular parts in the outer shape of the electronic tuner 1, it is preferable to provide an appropriate radius or chamfer. This is because this makes it easier to fit the package into a carrying member (for example, a magazine, tray, reel, etc.), thereby making it easier to package using an automatic machine and attach it to the set-side board 2.

Although the present invention has been described above in relation to an electronic tuner, the present invention is applicable not only to electronic tuners but also to peripheral circuits (for example, VIF) in addition to the original tuner circuit.
), it can also be applied to so-called pack equipment, and furthermore, it can be applied to a wide range of high-frequency equipment in general.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a state in which an electronic tuner 1 according to an embodiment of the present invention is mounted on a set-side board 2. FIG.

FIG. 2 is a perspective view showing a printed circuit board 3 and a metal case 4 included in the electronic tuner 1 shown in FIG. 1, separated from each other.

3 is a perspective view showing the lower main surface of the printed circuit board 3 shown in FIG. 2. FIG.

4 is a diagram for explaining a preferred method for obtaining the area surrounded by the broken line of the printed circuit board 3 shown in FIG. 2. FIG.

FIG. 5 is a cross-sectional view showing an enlarged main part of FIG. 1;

FIG. 6 is a sectional view showing a combined state of a printed circuit board 3a and a metal case 4a in another embodiment of the invention.

FIG. 7 is a plan view schematically showing a printed circuit board 3b included in yet another embodiment of the invention.

[Explanation of symbols]

1 Electronic tuner 3, 3a, 3b Printed circuit board 4,4a Metal case 5 Upper wall part 6, 7, 8, 9 Side wall part 15, 16 Locking piece 19 Circuit parts 21 Earth pattern 25 Terminal 29 Conductive film 30, 31 Solder

Claims (1)

[Claims] 1. A printed circuit board on which a ground pattern is formed, a plurality of circuit components mounted on one main surface of the printed circuit board, the circuit components are electromagnetically shielded together with the ground pattern, and the and a metal case combined with the printed circuit board so as to surround the circuit components together with the printed circuit board, and an edge portion of the printed circuit board is provided with a plurality of terminals formed of a film-like conductor. high frequency equipment.