JPH07283573A - Shield - Google Patents

Abstract

PURPOSE:To simplify a construction and an assembling process and further an electrical construction and to enable attainment of a stable high-frequency operation by shielding a plurality of circuit boards with surface mount devices from each other and the whole thereof without fail. CONSTITUTION:Printed boards 13a and 13b of which the rear sides are put together are shielded by a shield pattern 17 joined with these rear sides. The printed boards are disposed, being held by an upper-side shield member 11 and a lower-side shield member 12 between and fixed by a screw M. Shielding is made so that high-frequency circuit components 14a and 14b are held in recessions 11a and 11b of the upper-side shield member 11 respectively. Shielding is made also so that a high-frequency circuit component 15 is held in a recession 12a of the lower-side shield member 12. The high-frequency circuit components are disposed in the two boards and a resistor and a resonance circuit for matching input-output impedance are dispensed with. Thus, the construction thereof is simplified and an operation is made stable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency signal processing system and a shield device for shielding the entire circuit, which is used in a microwave band radio device and the like.

[0002]

2. Description of the Related Art Conventionally, in a microwave band radio communication device or the like, each high frequency circuit of a transmission / reception system is shielded.
For example, abnormal oscillation due to feedback in a circuit having the same frequency is prevented. In addition, the fundamental oscillation frequency is multiplied by the target transmission frequency, and harmonics when mixing to obtain the target transmission frequency are prevented from mixing into the receiving section to prevent intermodulation and unreceivable frequencies. ing.

FIG. 7 is a perspective view showing the structure of an example of a conventional shield device. In FIG. 7, this example shows a plurality of printed circuit boards (circuit boards) 1a on which electronic components are surface-mounted,
1b, 1c, 1d, 1e, 1f are connected to metal plates 2a, 2b,
2c, 2d, 2e and the metal frame 3 are arranged in a frame. Furthermore, an upper lid 4 and a lower lid 5 of metal that close the upper and lower openings of the metal frame 3 are provided. The upper lid 4 and the lower lid 5 are provided with tongues 4a and 5a around them. The tongues 4a and 5a are elastically fitted into the linear recessed portions (or protruding portions) 6a and 6b of the metal frame 3, respectively, so that the upper lid 4 and the lower lid 5 are fixed to the metal frame 3. ing.

In this configuration, the metal plates 2a to 2e, the metal frame 3, the upper lid 4 and the lower lid 5 are individually manufactured and assembled, and therefore the configuration and the assembly process are complicated and are not suitable for mass production. Moreover, it becomes larger. Therefore, the metal plates 2a to 2e,
Although the metal frame 3 is also integrally manufactured by metal molding (die casting), since the printed boards 1a to 1f of individual blocks are mounted on the metal frame in this case as well, Miniaturization cannot be achieved. Furthermore, the metal frame 3
When the upper cover 4 and the lower cover 5 are closed, unwanted radiation is likely to occur from the gap, particularly in the microwave band of high frequency.
Furthermore, the printed boards 1a to 1f which are individual blocks
In this case, a circuit configuration for matching the impedance between the input and output terminals, for example, a resonance circuit of a resistor, a lumped constant coil, and a capacitor is required, and the configuration becomes complicated.

To improve this, an example is known in which a ground pattern is provided on the entire back surface of a printed circuit board on which electronic components are surface-mounted to provide a shield. For example, JP-A-2-27
In the example shown in Japanese Patent No. 1656, a ground pattern is formed on the entire back surface of each of the two surface mount printed circuit boards,
It shields between the two printed circuit boards. Further, side plates are provided around these two printed circuit boards, and the upper and lower openings are covered with a metal plate or a metal base to shield the whole.

[0006]

In the above-mentioned conventional Japanese Patent Laid-Open Publication No. Hei 2-271656, the shield effect between the two printed circuit boards is high because the circuit pattern is used, and the shield is suitable for mass production. Although suitable, it is conceivable that the printed circuit board is covered with a side plate, a metal plate, and a metal stand that are individually manufactured, which complicates the configuration and the assembly process.

The present invention has been made in view of the above circumstances, and can reliably shield a plurality of surface-mounted circuit boards and the entire circuit board, simplify the configuration and assembly process, and further It is an object of the present invention to provide a shield device having a simple structure and capable of stable operation.

[0008]

In order to achieve the above object, the shield device according to claim 1 has a circuit component mounted on one surface and a shield member disposed on substantially the entire other surface. It is configured to include a plurality of the circuit boards and two shield members that are provided on both sides with the plurality of circuit boards sandwiched in between to form a space for accommodating the components mounted on the circuit boards.

According to another aspect of the shield device of the present invention, the plurality of circuit boards have two circuit boards each having a circuit component mounted on one surface thereof, and the other surface of the two circuit boards is substantially disposed. A shield pattern that is in close contact with the entire surface is provided, and two circuit boards are joined with the shield pattern sandwiched therebetween.

A shield device according to a third aspect of the present invention has a plurality of circuit boards, each of which has a circuit component mounted on one surface thereof as a plurality of circuit boards, and the other surface of the plurality of circuit boards is substantially disposed. The shield pattern is provided on the entire surface, the plurality of circuit boards are overlapped, and the two shield members are arranged with the plurality of circuit boards sandwiched therebetween.

According to a fourth aspect of the shield device, a plurality of circuit boards including circuit components are arranged so that the entire circumference thereof is covered with two shield members.

According to a fifth aspect of the shield device, the circuit patterns of the plurality of circuit boards are connected by the through holes and the connecting wires provided in the insulating member of the circuit boards.

According to the sixth aspect of the shield device, the two shield members are fixed by the screws of the conductors.

[0014]

According to the shield device of the present invention having the above-mentioned structure, the circuit component is mounted on one surface of each of the plurality of circuit boards, and the shield member is closely adhered to substantially the entire other surface. Are arranged. Then, sandwiching this circuit board or covering the entire circumference, two shield members are arranged on both sides of the circuit board while being fixed by screws that conduct electricity. In this case, the circuit components of the circuit board are placed in the space of the shield member. Therefore, the surface-mounted circuit boards are shielded from each other. Furthermore, the circuit components of the circuit board are individually shielded. For example, shielding is performed for each circuit so that the circuit components of the high-frequency amplifier circuit of the receiver and the oscillator circuit of the transmitter are housed in the space provided in the shield member.

According to another aspect of the shield device of the present invention, the two circuit boards, on which the circuit components are respectively mounted on one surface, are joined to the entire other surface by sandwiching a shield pattern provided in close contact with each other. ing. Therefore, all the circuits are arranged on the two circuit boards so that the best operation can be obtained. Therefore, for example, when each circuit is divided into blocks, elements and circuits for performing input / output impedance matching. Is unnecessary, the electrical configuration is simplified, and
It will operate stably at high frequencies.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the shield device of the present invention will be described with reference to the drawings. 1 is a perspective view showing the structure of an embodiment of the shield device of the present invention in a diffused manner, and FIG. 2 is a sectional view showing the structure taken along the line AA of FIG. 1 and 2, this example shows a board unit 10 having two printed boards on which high-frequency circuit components of a receiver and a transmitter such as a microwave radio communication device are surface-mounted.
And a schematic configuration of an upper shield member 11 and a lower shield member 12 which are fixed by screws M and are made by metal molding so as to cover upper and lower component mounting sides of the board unit 10 in the drawing. Has been done.

The board unit 10 includes two printed circuit boards 13
The back sides of a and 13b are configured to be aligned with each other, and high frequency circuit components 14a and 14b are surface-mounted on the upper surface of the printed circuit board 13a in the figure. Similarly, the printed circuit board 13b also has a high frequency circuit component 1 on the lower surface in the figure.
5 is surface-mounted. Further, the printed circuit board 13
On the back surfaces of a and 13b, a shield pattern 17 of ground potential is provided on the entire surface of the substrate, and the back sides of the printed boards 13a and 13b are joined with the shield pattern 17 interposed therebetween.

The upper shield member 11 is made by metal molding, and the positions of the high frequency circuit components 14a and 14b of the printed circuit board 13a and the recesses 11a and 11b which are box-shaped spaces for accommodating these components are formed. Further, a recess 11c is formed on the right side surface in the figure.
In the recess 11c, for example, a duplexer (shared device) for the transmission system and the reception system, which is composed of the high-frequency circuit component 14a.
The coaxial connector 20 to be connected to is fixed with a screw N. Further, at four corners of the upper shield member 11, this member and the two printed circuit boards 13a and 13b are sandwiched, and the lower shield member 12 is fixed by screws M which are inserted into the through holes 18 of the board unit 10. A hole 21 is provided for this purpose. In the figure, only one screw M and hole 21 are shown.

The lower shield member 12 is made by metal molding, and the position of the high frequency circuit component 15 on the printed circuit board 13b and the recess 12 which is a box-shaped space for accommodating this component.
a is formed, and a recess 12b is formed on the right side surface in the figure.
Are formed. The coaxial connector 20 is provided in the recess 12b.
A brim member is arranged. Further, screw holes 23 into which the ends of the screws M are screwed are provided at the four corners of the lower shield member 12, as shown by one in the figure.

In this case, the upper shield member 11 and the lower shield member 12 are configured to be electrically connected to the shield pattern 17. For example, a ground pattern is provided around the component mounting side of the printed circuit boards 13a and 13b, and this ground pattern is used as the upper shield member 11 and the lower shield member 1.
When it is configured so as to be in contact with 2, the potentials thereof are made constant and a stable shield effect is obtained.

FIG. 3 is a sectional view showing a connection state of the circuit patterns on the printed boards 13a and 13b shown in FIGS. In FIG. 3, the circuit pattern 24 of the printed circuit board 13a and the circuit pattern 25 of the printed circuit board 13b are connected by a connection line 27 described below.
The circuit pattern 26 and the shield pattern 17 on the printed circuit board 13a are connected by through holes 28. In this way, the circuit patterns on the printed circuit boards 13a and 13b are connected by connecting lines or through holes to connect the input / output terminals of the circuit.

FIG. 4 is a sectional view showing a mounted state of the coaxial connector 20 shown in FIGS. In FIG. 4, in this example, the collar member of the coaxial connector 20 is arranged by being fitted into the recess 11c of the upper shield member 11 and the recess 12b of the lower shield member 12, and the contact 20a of the coaxial connector 20 is Rolled connecting member 20
The end of b is connected to the input / output end of the high-frequency circuit component 14a, for example, a duplexer (shared device). In addition,
Although the insulating member 35 is provided around the connecting member 20b, the insulating member 35 may be omitted. That is, the connecting member 20b may be arranged in the hollow.

Next, the operation and function of the configuration of this embodiment will be described. Printed circuit boards 13a, 13b
Manufactures the high-frequency circuit components 14a, 14b, 15 by using a conventional surface mounting technique, for example, an automatic component supply device, an automatic solder coating device, a reflow device, or the like. Further, the circuit pattern between the printed circuit boards 13a and 13b is connected by a through hole or a connecting wire 27 formed by applying a conductor solvent to the through hole to make a circuit connection.

The substrate portion 10 having this structure is sandwiched between the upper shield member 11 and the lower shield member 12, and the screw M
Fixed by. In this case, the printed board 1 of the board unit 10
3a and 13b are shielded by the shield pattern 17 on the back side, and the shield pattern 17 prevents the cross modulation and the unreceivable frequency due to the wraparound of radio waves in the high frequency circuit components 14a, 14b and 15. Further, abnormal oscillation due to feedback in a circuit having the same frequency does not occur. Further, in the recesses 11a and 11b of the upper shield member 11, the high-frequency circuit components 14a and 1b, respectively.
4b is covered and shielded. Further, the high-frequency circuit component 15 is covered and shielded by the recess 12a of the lower shield member 12.

In this case, a strict shield effect can be obtained, and the shield pattern 17 of the substrate portion 10 and the printed circuit boards 13a and 13b can be easily mass-produced by automation in a conventional device. Furthermore, since the upper shield member 11 and the lower shield member 12 are also metal-molded, mass production thereof is easy, and there is no need to assemble and complete individual shield members as described with reference to FIG.
The structure and the assembly process are simplified.

Further, in this structure, the high frequency circuit components 14a, 1 are provided on the two printed circuit boards 13a, 13b, respectively.
4b and 15 are arranged. In this case, the circuit configuration is possible in the best arrangement state. For example, as described with reference to FIG. 7 above, it is not necessary to align and connect the input / output impedances of the individual blocks that are configured by the individual blocks and are spaced apart from each other, so that stable operation can be obtained. A resistor and a resonance circuit for matching the input and output impedances are not required, and the structure is simplified.

FIG. 5 is a sectional view showing another structural example in which the entire printed circuit boards 13a and 13b are housed in the upper shield member 11 and the lower shield member 12. 5, in this example, the vertical and horizontal sizes of the printed circuit boards 13a and 13b are made smaller than the vertical and horizontal sizes of the printed circuit boards 13a and 13b, and the printed circuit boards 13a and 13b are arranged on the upper shield member 11 side.
And is housed in the lower shield member 12. Therefore, the mating side (inside) of the upper shield member 11 and the lower shield member 12 has a concave shape so that the printed circuit boards 13a and 13b are arranged. Other configurations are
The configuration is the same as that shown in FIGS. 1 to 4. In this configuration, the upper shield member 11 and the lower shield member 12 cover the entire circumference of the printed circuit boards 13a and 13b, so that a higher shield effect can be obtained.

FIG. 6 is a cross-sectional view showing an example in which a printed circuit board is composed of three or more layers. In FIG. 6, this example is based on the printed circuit boards 13a and 13b shown in FIGS.
A new printed circuit board 37 is provided between and.
This new substrate is also provided with the high frequency circuit component 39 by surface mounting and the shield pattern 38 is provided on the entire back surface of the substrate. This multilayer printed circuit board
The screws M may be inserted through the through holes at the four corners, and spacers may be provided so that the multilayer printed circuit boards are stacked and arranged at required intervals. By mounting the high-frequency circuit components on the printed circuit board and providing the shield pattern on the entire back surface in this way, it becomes possible to shield each of the multilayer printed circuit boards, resulting in a more complex and versatile circuit configuration. Will be possible. Other configurations are similar to those shown in FIGS. 1 to 5.

In this embodiment, the upper shield member 1
1. The lower shield member 12 is made by metal forming, but it may be made by shaving with a machine tool.
The plastic molded member may be coated with a conductor or formed by metal plating to be used.

[0030]

As described above, claims 1, 3 to 6 are provided.
The shield device described has circuit components mounted on one surface,
In addition, the shield member is placed in close contact with the entire other surface. Further, two shield members are arranged on both sides of the circuit board so as to sandwich the circuit board or to cover the entire circumference of the circuit board while fixing the shield members with conductive screws. In this case, since the circuit components of the circuit board are accommodated in the space of the shield member, the surface-mounted circuit boards can be reliably shielded, and the circuit components of the circuit board can be individually and reliably shielded. Have an effect. In addition, since the circuit board and the shield member can be manufactured by a conventional mass production method, there is an advantage that the configuration and the assembly process can be simplified.

According to another aspect of the shield device of the present invention, the two circuit boards, on which the circuit components are respectively mounted on one surface, are bonded to each other with a shield pattern closely adhered to the entire other surfaces of the two circuit boards, and Since a large number of circuits can be arranged on this one circuit board, the elements and circuits that perform input / output impedance matching are not required, as in the case of dividing each circuit into blocks, for optimal operation. You can arrange the circuit components as you do, simplifying the configuration,
Moreover, there is an effect that a stable operation can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a diffused configuration of an embodiment of a shield device of the present invention.

FIG. 2 is a cross-sectional view showing a configuration taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing a connection state of circuit patterns on the printed board shown in FIG.

4 is a cross-sectional view showing a mounted state of the coaxial connector shown in FIG.

5 is a cross-sectional view showing another configuration example in which the entire printed circuit board is housed in the shield member shown in FIG.

FIG. 6 is a cross-sectional view showing an example in which the printed circuit board is configured in multiple layers in the embodiment.

FIG. 7 is a perspective view showing a configuration of an example of a conventional shield device.

[Explanation of symbols]

 10 board part 11 upper side shield member 11a, 11b, 12a recessed part 12 lower side shield member 13a, 13b printed circuit board 14a, 14b, 15 high frequency circuit component 17 shield pattern M screw

Claims (6)

[Claims] 1. A circuit component is mounted on one surface, and
A plurality of circuit boards in which a shield member is arranged on substantially the entire other surface, and a space for accommodating the mounting components of the plurality of circuit boards are formed, and are arranged on both sides with the plurality of circuit boards sandwiched therebetween. A shield device comprising: 2. A plurality of circuit boards have two circuit boards each having a circuit component mounted on one surface thereof, and the other surface of the two circuit boards is provided with a shield pattern which is adhered to substantially the entire surface. The shield device according to claim 1, wherein the two circuit boards are bonded to each other with the shield pattern interposed therebetween. 3. A plurality of circuit boards have a plurality of circuit boards on which circuit components are respectively mounted on one surface, and a shield pattern is provided on substantially the entire other surface of the plurality of circuit boards. The shield device according to claim 1, wherein the plurality of circuit boards are overlapped with each other, and the two shield members are arranged with the plurality of circuit boards sandwiched therebetween. 4. The shield device according to claim 1, wherein the plurality of circuit boards are arranged such that the entire circumference including the circuit components is covered with two shield members. 5. The shield device according to claim 1, wherein the circuit patterns of the plurality of circuit boards are connected by a through hole and a connecting wire provided in an insulating member of the circuit board. 6. The shield device according to claim 1, wherein the two shield members are fixed by a screw of a conductor.