JP3628832B2 - Shield case for electronic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shield case for an electronic device having a high frequency circuit such as a tuner for receiving television broadcasts.
[0002]
[Prior art]
In general, a circuit board having an oscillation circuit or the like reduces unnecessary radiation to the outside, and a circuit board having a high-gain high-frequency amplifier circuit prevents noise from entering from other circuits or from the outside. For this reason, it is mounted in a shield case made of a conductive metal.
[0003]
FIG. 3 is an exploded perspective view of a conventional shield case as seen from the lower surface side. As shown in FIG. 3, the shield case is housed in a metal frame 1 having both upper and lower surfaces opened, and inside the metal frame 1. The circuit board 2 and a pair of upper and lower covers 3 and 4 attached to both openings of the metal frame 1 are mainly configured. A pair of mounting legs 5 and 6 are provided at opposing corners at the opening end on the lower surface side of the metal frame 1, and these mounting legs 5 and 6 are bent at right angles from the lower end of the outer wall to the outside. Is formed. Circuit components are mounted on the circuit board 2 and divided into a plurality of rooms by a partition plate (not shown). The upper cover 3 and the lower cover 4 are formed in a substantially rectangular shape so as to cover the openings on the upper surface and the lower surface of the metal frame 1, and engagement pieces 3 a and 4 a having a “<” shape in cross section are formed on the respective peripheral edges. Yes.
[0004]
When assembling the shield case configured as described above, the circuit board 2 is accommodated in the metal frame 1, and the ground pattern of the circuit board 2 is illustrated as the inner surfaces of the outer walls 1 a and 1 b of the metal frame 1. After soldering to the partition plate, the engagement pieces 3a, 4a of the upper cover 3 and the lower cover 4 are brought into elastic contact with the outer walls 1a, 1b of the metal frame 1 so that the covers 3, 4 are attached to the metal frame. It adheres to the opening of the upper surface and the lower surface of the body 1, respectively. The shield case after assembly is mounted on an external printed board (not shown), and the mounting legs 5 and 6 are mechanically fixed to the printed board by means such as screws, and the printed board and the circuit board 2 are also fixed. Are electrically connected via connectors and terminals (not shown).
[0005]
[Problems to be solved by the invention]
By the way, in the above-described conventional shield case, when the covers 3 and 4 are attached to the openings on the upper and lower surfaces of the metal frame 1, the outer walls 1a and 1a of the metal frame 1 are shown as indicated by broken lines in FIG. Since 1b receives the pressing force from the engagement pieces 3a and 4a and is deformed inward, the attachment legs 5 and 6 are inclined with this deformation. If the mounting legs 5 and 6 are tilted in this way, the mounting position of the mounting legs 5 and 6 with respect to the printed circuit board is shifted when the shield case is mounted on the printed circuit board, so that the mounting work becomes very troublesome. was there.
[0006]
[Means for Solving the Problems]
According to the present invention, an attachment leg for attaching to a printed circuit board is provided at one end of the outer wall of the metal frame, and the extension line of the contacted portion where the engagement piece of the cover abuts from one end of the outer wall in the vicinity of the attachment leg. A slit extending to a position exceeding the upper limit is formed. When such a slit is formed, the deformation of the outer wall when the cover is attached to the metal frame is blocked by the slit, so that the mounting leg can be prevented from shifting from the normal position.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the shield case of the electronic device according to the present invention, the metal frame having an attachment leg at one end of the outer wall and opening at least the surface on the one end side, the circuit board housed inside the metal frame, An engagement piece that contacts an abutted portion of the outer wall of the metal frame, and a cover that is attached to cover the opening, and is adjacent to the mounting leg on the outer wall of the metal frame. A slit was formed, and the slit was extended from the end of the opening to a position exceeding the extension line of the contacted portion.
[0008]
【Example】
The embodiment will be described with reference to the drawings. FIG. 1 is an exploded perspective view of the shield case according to one embodiment of the present invention as seen from the lower surface side, and FIG. 2 is an enlarged view of the main part in the assembled state of the shield case. In these drawings, the same components as those shown in FIGS. 3 and 4 described above are denoted by the same reference numerals.
[0009]
As shown in FIGS. 1 and 2, the shield case according to the present embodiment is different from the above-described conventional example in that slits 7 are provided in the vicinity of the mounting legs 5 and 6 on the outer walls 1a and 1b of the metal frame 1, respectively. 8, and the slits 7 and 8 prevent the deformation of the outer walls 1 a and 1 b of the metal frame 1 from affecting the mounting legs 5 and 6. This is the same as the conventional example. One slit 7 extends upward along the vertical direction from the lower end of the outer wall 1a, and the upper end 7a is a portion where the engaging piece 4a of the lower cover 4 abuts against the outer wall 1a of the metal frame 1 (hereinafter, this is covered). It extends above the extension line of the contact portion (referred to as reference portion 1c). Similarly, the other slit 8 also extends upward along the vertical direction from the lower end of the outer wall 1b, and its upper end also reaches above the extension line of the contacted portion 1c. That is, the slits 7 and 8 are located between the mounting legs 5 and 6 and the engaging piece 4a of the lower cover 4 and are formed across the extended line of the contacted portion 1c.
[0010]
In the shield case configured as described above, when the lower cover 4 is attached to the opening on the lower surface of the metal frame 1, the engagement piece 4 a elastically contacts the outer walls 1 a and 1 b of the metal frame 1, Although the outer side walls 1a and 1b are pressed inward (refer to FIG. 4), the mounting legs 5 and 6 and the contacted portion 1c are separated by the slits 7 and 8, and thus are caused by the pressing of the engaging piece 4a. The deformation to be blocked is blocked by the slits 7 and 8, respectively, and the inclination of the mounting legs 5 and 6 can be prevented. Therefore, when the shield case is mounted on an external printed circuit board (not shown), the mounting positions of the mounting legs 5 and 6 and the printed circuit board are maintained, and the mounting operation can be easily performed.
[0011]
In the above embodiment, the case where the slits 7 and 8 are formed upward from the lower ends of the outer walls 1a and 1b of the metal frame 1 and the slit is not formed on the upper end side of the metal frame 1 has been described. The reason is that there is little influence from the upper cover 3 attached to the opening far from the mounting legs 5 and 6, and the upper end side of the metal frame 1 is formed by a partition plate provided inside the metal frame 1. For example, the strength can be increased. However, if necessary, the upper ends of the slits 7 and 8 extend to above the contacted portion 1d where the engaging piece 3a of the upper cover 3 contacts the outer walls 1a and 1b of the metal frame 1, or the metal frame A slit may be formed from the upper end side of 1 downward.
[0012]
Further, in the above embodiment, the case where the slits 7 and 8 are formed only on the outer wall on which the mounting legs 5 and 6 are formed among the four sides of the metal frame 1 has been described. A slit can also be formed.
[0013]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
[0014]
A metal frame having an attachment leg at one end of the outer side wall and having an opening at least on one end side thereof, a circuit board housed inside the metal frame, and a contact of the outer wall of the metal frame And a cover that is attached to cover the opening, and a slit is formed adjacent to the mounting leg on the outer wall of the metal frame. Since it extends from the end of the opening to a position that exceeds the extension line of the contacted part, the deformation of the outer wall when the cover is attached to the metal frame is blocked by the slit, so the mounting leg is regular The shield case can be easily mounted on an external printed circuit board.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a shield case according to an embodiment of the present invention as viewed from the lower surface side.
FIG. 2 is an enlarged side view showing a main part in an assembled state of the shield case.
FIG. 3 is an exploded perspective view of a conventional shield case as viewed from the lower surface side.
FIG. 4 is an explanatory view showing a deformed state of the metal frame when a cover provided in the shield case is attached.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Metal frame 1a, 1b Outer wall 1c Contacted part 2 Circuit board 3 Upper cover 4 Lower cover 3a, 4a Engagement piece 5, 6 Mounting leg 7, 8 Slit

Claims (1)

A metal frame having an attachment leg at one end of the outer side wall and having an opening at least on one end side thereof, a circuit board housed inside the metal frame, and a contact of the outer wall of the metal frame An engagement piece abutting on the part, and a cover attached to cover the opening,
A slit is formed in the outer wall of the metal frame adjacent to the mounting leg, and the slit is extended from the end of the opening to a position exceeding the extension line of the contacted portion. Equipment shield case.

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