JP2000022379A - Digital communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital communication equipment for surely preventing an influence between a high-frequency circuit and a digital circuit to one another by facilitating its assembly. SOLUTION: An upper cover 2 is mounted at an upper side of a chassis case body 1, and a lower cover 3 is mounted at its lower side. Flange-like chassis protrusions 4 are provided along a central part of an inside peripheral surface of the body 1. A high-frequency circuit board 5 and a chassis plate 6 are mounted at lower sides of the protrusions 4 via screws 7. A transmitter/ receiver circuit having, for example, a high-frequency amplifier, a frequency converter, an oscillator and the like placed thereon is carried on the board 5, and circuit constituting components 8 are mounted on its upper surface. The plate 6 is formed in a ring state, and a digital circuit board 9 is mounted on its lower surface via screws 10. A digital modulator/demodulator circuit, a low-frequency circuit and the like are placed on the board 9, and circuit constituting components 11 are mounted on its lower surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic equipment,
In particular, the present invention relates to a digital communication device including a high-frequency circuit (high-frequency amplifier circuit, frequency conversion circuit, oscillation circuit) and a digital circuit.

[0002]

2. Description of the Related Art In an electronic device, for example, a digital communication device having a digital modulation / demodulation circuit, especially when wireless communication is used, the arrangement of an analog frequency conversion portion, which is a high-frequency circuit, is important in the performance of the device. In general, a design method is used that clearly separates high-frequency circuits and digital circuits, and care is taken not to affect the quality of both signals.

Conventionally, as shown in FIGS. 5 and 6, the high-frequency circuit board is soldered to the shield wall to stabilize the characteristics of the high-frequency circuit. FIG. 5 shows a configuration of a high-frequency circuit board portion, and FIG. 6 shows a state where the high-frequency circuit board is mounted on a chassis. In FIG. 5, a high-frequency circuit board 21 has an earth pattern 22 formed on the entire lower surface and a part of the upper surface, and the lower surface and the earth pattern 22 on the upper surface are electrically connected through through holes 23. On the upper surface of the high-frequency circuit board 21,
Parts (not shown) constituting the high-frequency circuit are mounted.
On the outer peripheral surface of the high-frequency circuit board 21, a plurality of grounding conductive surfaces 24 formed by plating are provided at predetermined intervals. The ground conductive surface 24 is used to make the ground of each layer of the substrate common.

As shown in FIG. 6, the high-frequency circuit board 21 has an outer peripheral surface abutting against a chassis wall surface 25, and soldering 26 is performed on the upper or lower surface of the substrate to connect the ground pattern 22 to the chassis wall surface 25. . In this case, as the frequency to be processed by the high-frequency circuit board 21 increases, the number of locations of the solder 26 needs to be increased.

[0005]

In the conventional method of soldering the outer peripheral surface of the high-frequency circuit board 21 in contact with the chassis wall surface 25 as in the above-mentioned conventional method, the ground pattern 22 and the chassis wall surface 25 are connected to each other by the soldering 26. , The higher the frequency, the greater the number of locations of the solder 26, which makes the assembly more troublesome.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a digital communication device which is easy to assemble and can reliably prevent the influence between a high-frequency circuit and a digital circuit. .

[0007]

According to a first aspect of the present invention, there is provided an electronic apparatus comprising: a case main body; a flange-shaped chassis protrusion formed along an inner peripheral surface of the case main body; A first circuit board and a chassis plate which are stacked and screwed on the side, a second circuit board which is screwed below the chassis plate, and a shielding upper lid mounted on the upper side of the case body. And a lower cover for shielding mounted on the lower side of the case body.

According to a second aspect of the present invention, there is provided a digital communication device including a high-frequency circuit board on which a transmission / reception circuit is mounted and a digital circuit board on which a digital circuit is mounted. A flange-shaped chassis projection to be formed, a high-frequency circuit board and a chassis plate stacked and screwed below the chassis projection, a digital circuit board screwed below the chassis plate, and the case It is characterized by comprising a shielding upper lid mounted on the upper side of the main body, and a shielding lower lid mounted on the lower side of the case main body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an assembling structure of a digital communication apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view showing a configuration of a high-frequency circuit board portion, and FIG. It is sectional drawing which shows a state. FIG. 4 is an exploded perspective view showing an assembly structure of the digital communication device in FIG.

In FIG. 1, reference numeral 1 denotes a chassis / case body, on which an upper cover 2 for shielding is mounted, and a lower lid 3 for shielding is mounted on the lower side. The shield upper lid 2 and the lower lid 3 are bent so that their outer peripheries are located outside the chassis / case body 1, and cuts are provided at predetermined intervals in the bent portions to provide elasticity. Is attached to the chassis / case main body 1 by the elastic force of.

The chassis / case body 1 is provided with a flange-shaped chassis projection 4 along the center of the inner peripheral surface. A high-frequency circuit board 5 is provided below the chassis projection 4.
And the chassis plate 6 is attached by screws 7. The high-frequency circuit board 5 has a transmission / reception circuit including, for example, a high-frequency amplifier circuit, a frequency conversion circuit, an oscillation circuit, and the like. The circuit component 8 is mounted on the upper surface. The chassis plate 6 is formed in a ring shape as shown in FIG. 4, and a digital circuit board 9 is attached to a lower surface thereof with screws 10. A digital modulation / demodulation circuit, a low-frequency circuit, and the like are mounted on the digital circuit board 9, and a circuit component 11 is mounted on the lower surface.

The structure of the digital communication device will be described in detail with reference to FIG. A plurality of round holes 7a for inserting the screws 7 are provided at predetermined intervals in the chassis projection 4 of the chassis / case main body 1. An external interface connector 12 is attached to one side surface of the chassis case body 1 below the chassis projection 4 by screws 13.

The high-frequency circuit board 5 attached to the chassis projection 4 is provided with a round hole 7b at a position corresponding to the round hole 7a of the chassis projection 4. Further, a tap 7c is provided on the chassis plate 6 at a position corresponding to the round hole 7b of the high-frequency circuit board 5.

The digital circuit board 9 is provided with round holes 10a for the screws 10 at the four corners and the center of the long side. Further, a tap 10b is provided on the chassis plate 6 at a position corresponding to the round hole 10a of the digital circuit board 9.
Is provided. A cut 14 is provided on the side of the digital circuit board 9, that is, on the side of the external interface connector 12, and the circuit of the digital circuit board 9 and the external interface connector 12 are formed at the cut 14. You can connect.

As described above, the chassis / case main body 1, the high-frequency circuit board 5, the chassis plate 6, the digital circuit board 9
After the round hole processing and the tapping processing are performed, the high frequency circuit board 5 and the chassis plate 6 are stacked on the chassis projection 4 of the chassis / case body 1 from below, and the chassis projection 4 is formed.
A screw 7 is inserted into the round hole 7a from above, and further, the round hole 7b of the high-frequency circuit board 5 is inserted and screwed to the tap 7c of the chassis plate 6. In this case, on the upper surface of the high-frequency circuit board 5, as shown in FIG. 2, a ground pattern 15 is formed on the entire lower surface and around the upper surface, and the lower surface and the ground pattern 15 on the upper surface are electrically connected by through holes 16. Have been. Therefore, when the high-frequency circuit board 5 and the chassis plate 6 are mounted on the chassis projection 4 of the chassis / case main body 1 as shown in FIG. 3, the ground pattern 15 is pressed against the lower surface of the chassis projection 4, and the ground pattern 15 and the chassis projection 4 are pressed. The entire lower surface of 4 is electrically connected.

Next, the digital circuit board 9 is positioned below the chassis plate 6, and the screw 10 is inserted into the round hole 10a from below.
And screwed to the tap 10b of the chassis plate 6.

After the high-frequency circuit board 5, the chassis plate 6, and the digital circuit board 9 are mounted on the chassis / case main body 1, a shielding upper lid 2 is mounted on the upper part of the chassis / case main body 1, and the shielding lower lid is mounted on the lower part. Attach the lower lid 3.

As described above, according to the present invention, a flange-like chassis projection 4 is provided on the inner surface of the chassis / case body 1.
And the high-frequency circuit board 5 and the chassis plate 6 are laminated and mounted on the chassis projection 4, so that the entire lower surface of the chassis projection 4 is electrically connected to the ground pattern 15 formed on the high-frequency circuit board 5. It will be in the state that was done.
Therefore, even if the frequency processed by the high-frequency circuit board 5 becomes high, it is not necessary to increase the number of screws 7 fixing the high-frequency circuit board 5 and the chassis plate 6, and a stable high-frequency earth can be provided with less screws. Can be realized. Further, since the number of screws used can be reduced as described above, the assembling operation is easy, and the disassembling operation for inspection, repair, and the like can be easily performed.

Further, since the high-frequency circuit board 5 and the digital circuit board 9 are provided independently and separated from each other by the chassis plate 6, higher-order spurious from the digital system of the digital circuit board 9 is reduced. No influence on the oscillator No. 5 or the influence on the mixed conversion part does not degrade the quality of the modulation / demodulation signal due to the influence of noise on the intermediate frequency band output signal.

In the above embodiment, the case where the present invention is applied to a digital communication device is described. However, the present invention is not limited to the digital communication device, but can be applied to other electronic devices in the same manner. is there.

[0022]

As described above in detail, according to the present invention, in a digital communication device comprising a high-frequency analog circuit and a digital modulation / demodulation circuit, a chassis projection is provided on the inner surface of the chassis / case body, and the chassis projection is provided on the chassis projection. Laminate the board and chassis plate and screw them together,
Since the digital circuit board is screwed to the lower side of the chassis plate, stable high-frequency earthing and a shielding effect can be realized with less screws.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an assembly structure of a digital communication device according to an embodiment of the present invention.

FIG. 2 is an exemplary perspective view of a high-frequency circuit board according to the first embodiment;

FIG. 3 is an exemplary sectional view showing a state in which the high-frequency circuit board according to the embodiment is attached to a chassis protrusion;

FIG. 4 is an exemplary exploded perspective view showing an assembly structure of the digital communication device according to the embodiment;

FIG. 5 is a perspective view of a high-frequency circuit board in a conventional digital communication device.

FIG. 6 is a sectional view showing a state where the high-frequency circuit board in FIG. 5 is attached to a chassis;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chassis case main body 2 Shield upper lid 3 Shield lower lid 4 Chassis protrusion 5 High frequency circuit board 6 Chassis plate 7 Screw 8 Circuit component 9 Digital circuit board 10 Screw 11 Circuit component 12 External interface connector 13 Screw 14 Notch 15 Earth pattern 16 Through hole

Claims (2)

[Claims] 1. A case body, a flange-shaped chassis projection formed along an inner peripheral surface of the case body, and a first circuit board and a chassis stacked and screwed below the chassis projection. A board, a second circuit board screwed to a lower side of the chassis plate, a shielding upper lid mounted on an upper side of the case main body, and a shielding lower lid mounted on a lower side of the case main body. An electronic device comprising: 2. A digital communication device comprising a high-frequency circuit board on which a transmitting / receiving circuit is mounted and a digital circuit board on which a digital circuit is mounted, a case body and a flange formed along an inner peripheral surface of the case body. -Shaped chassis projection, a high-frequency circuit board and a chassis plate stacked and screwed below the chassis projection, a digital circuit board screwed below the chassis plate, and an upper side of the case body. A digital communication device comprising: a shield upper lid to be mounted; and a shield lower lid to be mounted below the case body.