JPH075672Y2 - Grounding structure of printed circuit board unit with shield cover - Google Patents

Description

[Detailed Description of the Invention] [Outline] Regarding a grounding structure of a printed board unit with a shielding cover to be mounted on a subrack, a grounding structure is provided in which the handleability of the printed board unit is good and it surely contacts the frame structure of the subrack. For the purpose of the subrack, which is configured by collectively mounting the printed circuit board units that are configured on the printed circuit board by plug-in connection to configure the device, attach it to the mounting surface of the subrack and the printed circuit board of the mounted printed circuit board unit. In addition to the grounding metal fitting that has a front-lowering inclined surface in the gap A and the extension area of the gap A that is formed between the lower surface of the shielding cover and the front edge of the subrack, and the lower surface or the front surface of the shielding cover. When mounting the printed circuit board unit, it is elastically contacted with the inclined surface of the grounding metal to conduct electricity, and is installed without protruding from the outer shape of the printed circuit board unit. It is composed of a contact piece with a beam.

[Industrial application field]

The present invention relates to a grounding structure for a printed board unit with a shielding cover mounted on a subrack.

As electronic communication devices are becoming smaller and more sophisticated, the ground connection is not only for circuit grounding, but also for grounding shielded parts, shielded wiring, shielded structures, etc. Alternatively, there are various things such as grounding separately from the circuit ground depending on the speed, or grounding together, but generally the shielding structure (cover, case, frame, etc.) is called frame ground, and there is little high frequency resistance to each other, and stable conduction is achieved. Required to do so.

[Conventional technology]

 FIG. 3 shows a perspective view of a conventional example.

Until now, wireless communication devices that handle high frequencies used to have a completely shielded structure in which all the constituent circuits were housed inside a shielding case, but nowadays they handle wireless frequencies due to the miniaturization of components and advances in packaging technology. With the exception of the circuit configuration, printed circuit board units that have a circuit configuration on a standardized printed circuit board are collectively mounted by plug-in connection to the subrack.If necessary, attach a shielding cover to the printed circuit board to shield the units from each other. There is.

If the shielding structure is shown in a conventional example, it is as shown in FIG.
The printed circuit board unit 15 has a circuit configuration on the printed circuit board 2.
A shield cover 35 that covers the entire mounting area is fixed to the component mounting side on one side, and a connector 7 for plug-in connection is mounted on the rear part.

The shielding cover 35 is formed by forming a thin iron plate into a square frame shape, and a frame 36 having a screw seat 37 at each corner, and a screw seat 37 covering the frame 36.
And a lid 38 which is fixed to the printed board 2 with screws.

The subrack 45 includes a shelf for collectively mounting the printed board units 15, has concave rail-shaped guide portions 46 facing the upper and lower surfaces of the shelf at predetermined intervals, and has a connector for plug-in connection on the rear surface. Is mounted, and a back board 47 made of a printed board for connecting circuits of the mounted printed board units 15 to each other is attached, and guides the edges of the upper and lower opposite sides of the printed board 2 to the guide portion 46. When the printed board unit 15 is inserted from the front and pushed in, the rear connector 7 is plugged in and attached to the connector of the backboard 47, and the mounting is completed by operating a lock mechanism (not shown).

The shielding cover 35 is grounded by the terminals of the backboard 47, the printed wiring, and the ground wiring via the terminals of the connector 7 by the printed wiring in the unit of low frequency, but in the unit of the high frequency, the method of connecting by wiring is It does not have low resistance at high frequencies, and as shown in FIG.
A contact piece 65 formed by molding an elastic stainless steel thin plate is fixed to the front side of the front side of the sub-cover, which covers the entire front surface of the subrack 45 after the unit is mounted. The tip of the contact piece 65 elastically contacts the back surface to establish a conductive state, and is grounded to the frame in a short distance with little resistance.

Although not shown, as another grounding method of the shielding cover 35, there is also a method of fixing a similar contact piece to the lower surface of the frame 36 and directly contacting the mounting surface of the frame of the subrack 45.

[Problems to be solved by the device]

However, if the tip of the contact piece 65 does not protrude from the front edge of the printed board unit 15, stable ground contact cannot be obtained, and this protrusion makes the unit difficult to handle and deforms or damages the contact piece 65. That often happens.

Furthermore, when operated with the surface cover 48 of the subrack 45 removed, not only will the standard not be met, but EM
I may be considered ineligible in terms of measures.

There are problems such as.

The present invention has been made in view of the above problems, and an object thereof is to provide a grounding structure in which a printed board unit can be easily handled and can surely come into contact with a subrack frame structure.

[Means for Solving the Problems]

As shown in FIGS. 1 and 2, the above problem is caused by the printed board unit 1 having a circuit structure on the printed board 2,
In the subrack 4 that is collectively mounted by plug-in connection to form the device, the mounting surface 41 of the subrack 4 and the lower side surface 31 of the shielding cover 3 attached to the printed board 2 of the mounted printed board unit 1 Gap A and Gap A created between
In the extension area of the front side, the grounding metal fittings 5 and 55, which are provided with the inclined surfaces 51 and 52 which are inclined downward, are fixed to the front edge 42 of the subrack 4, and the printed board unit is attached to the lower side surface 31 or the front side surface 32 of the shielding cover 3. The shield of the present invention, which is composed of a contact path 6,61 which is elastically contacted and conducted to the inclined surfaces 51, 52 of the grounding metal 5, 55 when mounted on the mounting board 1, and which is provided without protruding from the outer shape of the printed board unit 1. This is solved by the grounding structure of the printed board unit with cover.

[Action]

That is, when the printed board unit 1 is mounted, a gap A is always provided between the lower side surface 31 of the shield cover 3 and the mounting surface 41 of the subrack 4.

This is because if the lower side surface 31 and the mounting surface 41 are brought into direct contact with each other, it is necessary to shift the mounting area of the printed board 2 downward to the whole to perform the mounting design. However, it is necessary to consider the play amount due to manufacturing dimensional variation in the insertion dimension, the mounting area must be reduced accordingly, and the inelastic surfaces contact each other, so that the contact position is constant. However, the contact pressure is dispersed in the area and becomes small, and stable contact cannot be expected.

Therefore, the contact piece 6, within the dimension of the gap A and its extension,
If the contact portion between the 61 and the subrack 4 is configured, the purpose is suitable.

Since the ground metal fittings 5 and 55 are fixed to the front edge 52 so that the contact portions have the inclined surfaces 51 and 52 within the A dimension, the contact portions are fixed to the shield cover 3 by mounting the printed board unit 1 from the front. It is possible to provide the tips of the contact pieces 6 and 61 elastically contacting the inclined surfaces 51 and 52 so as to be in a conductive state and to prevent a business trip from the outer shape of the printed board unit 1 when it is a single body. is there.

For example, the contact pieces 6 and 61 are formed by forming strips of elastic thin plates into a substantially V shape, and by fixing the strips outwardly to the lower side surface 31 or the front side surface 32, the other ends are inclined surfaces 51 and 52. It can be provided elastically and without the need for a business trip due to the outer shape of the unit.

The inclined surfaces 51 and 52 allow the tips of the contact pieces 6 and 61 to make a smooth contact without applying a sudden and unreasonable force, and also have a function of absorbing variations in the mounting position in manufacturing.

Thus, when handling the printed circuit board unit alone, the contact piece is not deformed or damaged, the handleability of the printed circuit board unit is good, and it is possible to provide a grounding structure that reliably contacts the frame structure of the subrack.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. Throughout the drawings, the same reference numerals denote the same objects. FIG. 1 (a) is a perspective view of an embodiment of the present invention, FIG. 1 (b) is a side view of the same main part, and FIG. 2 is a side view of the other part of the present invention.

In the printed board unit 1 of this embodiment, a circuit is formed on the printed board 2, a shield cover 3 covering the entire mounting area is fixed to one side of the component mounting side if necessary, and a plug line connector 7 is mounted on the rear side. is there.

The subrack 4 is provided with a shelf for collectively mounting the printed board unit 1, has concave rail-shaped guide portions 46 facing the upper and lower surfaces of the shelf at predetermined intervals, and has a connector for plug-in connection on the rear surface. And a back board 47 made of a printed board for connecting circuits of the mounted printed board units 1 to each other is mounted, and the edges of the upper and lower opposite sides of the printed board 2 are guided by the guide portion 46. When the printed board unit 1 is inserted from the front and pushed in, the connector 7 at the rear is plugged into the connector of the backboard 47 and mounted. When the connector 7 is fitted, the printed board unit 1 cannot be removed. It becomes a strong thing that can not be easily done,
The implementation ends with the same effect as the locked state.

The shield cover 3 is formed by forming a thin iron plate into a square frame shape, and has a frame 36 having a screw seat 37 at each corner, and a screw seat 37 that covers the frame 3.
The cover 38 has a lid 38 that is screwed and fixed to the cover cover 3, and has a grounding structure in which the grounding connection of the shield cover 3 is directly and stably brought into contact with the frame of the subrack 4 in a stable and reliable manner regardless of wiring.

In one embodiment, as shown in FIG. 1, on the front side surface 32 of the frame 36 of the shield cover 3, the contact side 6 formed by forming a thin plate of elastic stainless steel having a width of 10 mm into a substantially V shape, and the front portion of the printed board 2 are provided. It does not travel from the lower edge and sticks downward so as to protrude from the lower side surface 31 of the shielding cover 3.

On the other hand, the subrack 4 has a lower surface 31 of the shielding cover and a mounting surface 41 of the subrack 4 when the printed board unit 1 is mounted.
The grounding fitting 5 is screwed to a predetermined position of the front edge 42 so that the inclined surface 51 is provided in the front extension area of the space A generated between the grounding metal 5 and the front edge 42.

The grounding metal 5 is formed by forming a thin iron plate having a width of 12 mm and plated with Ni, forming a sloping surface 51 which is bent forward from the front edge 42 and downwardly folds. It serves as a detent when tightening the screws.

In another embodiment, as shown in FIG. 2, the printed board unit 1 is provided with a contact piece 61 which is substantially the same as the one described above, at a predetermined position on the lower side surface 31 of the shield cover 3 and under the printed board 2. The grounding metal fitting 55 that is fixed without traveling from the edge and screwed to the front edge 42 of the subrack 4 is almost the same as the above, and the sloping surface 52 is bent by bending it to the rear side of the front edge 42. It has a curved surface.

Thus, when the printed board unit 1 is attached to the subrack 4, the tip portions of the contact pieces 6 and 61 elastically contact the inclined surfaces 51 and 52 of the grounding fittings 5 and 55 to establish a ground connection.

The above embodiment shows an example, and the size and shape of the shield cover 3 is not limited as long as the contact pieces 6 and 61 can be provided at the positions where they can contact the grounding fittings 5 and 55 attached to the front edge 42. It doesn't matter. The subrack 4 may have a plurality of mounting shelves on the top and bottom, and the detailed structure is not limited to the above.
Since it does not affect the mounting of the unit even if it is located in an unnecessary place, it is possible to integrally form all the fixed positions.

[Effect of device]

As described above, with the grounding structure of the present invention, the contact piece is provided on the shield cover without traveling from the outer shape of the printed board unit,
When handling the printed board unit alone, deform the contact piece,
It will not be damaged and the printed board unit will be easy to handle.
In addition, a grounding structure that surely comes into contact with the subrack frame structure is obtained, and the practical effect is great.

[Brief description of drawings]

FIG. 1 is a side view of an essential part of another embodiment of the present invention, and FIG. 3 is a perspective view of an example of a conventional device. In the figure, 1,15 is a printed board unit, 2 is a printed board, 3,35 is a shielding cover, 4,45 is a subrack, 5,55 is a grounding metal, 6,61,6
5 is a contact piece, 7 is a connector, 31 is a lower side surface, 32 is a front side surface, 3
6 is a frame, 37 is a screw seat, 38 is a lid, 41 is a mounting surface, 42 is a front edge, 4
6 is a guide part, 47 is a backboard, 48 is a front cover, 51,
52 is an inclined surface.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Sadayuki Tetsu, 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa, Fujitsu Limited (56) References: 58-138392 (JP, U) (JP, U) Actually opened Sho 57-170592 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A subrack (4) comprising a printed board unit (1) circuit-configured on a printed board (2) which is collectively mounted by plug-in connection to form an apparatus. A gap A formed between the surface (41) and the lower side surface (31) of the shield cover (3) attached to the printed board (2) of the mounted printed board unit (1).
And, in the extended area of the gap A, the inclined surface (51) (5)
2), grounding metal fittings (5) (55) for conducting and fixing the front edge (42) of the subrack (4), and the lower side surface (31) or the front side surface (32) of the shielding cover (3).
When the printed board unit (1) is mounted, it elastically contacts the inclined surfaces (51) (52) of the grounding metal fittings (5) (55),
A grounding structure for a printed board unit with a shield cover, comprising: contact pieces (6) (61) that are electrically connected and are provided without protruding from the outer shape of the printed board unit (1).