JPH0246075Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Field to which the Invention Pertains> The present invention relates to a shield structure for a circuit portion of a printed wiring board of a wireless device on which electronic components are mounted and which requires shielding.

<Description of the Prior Art> Conventionally, in this type of shield structure, as shown in FIG. It has a structure that allows Since the contact surface of the shield case 2 with the printed wiring board 1 is formed flat, the contact surface pressure does not concentrate, and the accuracy of the plane may vary depending on the manufacturing conditions of the shield case, etc. There is also the problem that the printed wiring board 1 is bent in a fixed state, and the shielding effect is weak because electrical contact between the shielding case 2 and the printed wiring board 1 cannot be ensured.

In addition, in order to ensure electrical contact with this type of structure, as shown in Figure 1 b and c, we made many slits in the spring material and divided each piece into small pieces in either direction in the direction in which the shield case was tightened. There is also a method of ensuring electrical contact by sandwiching a shim 4 or the like, which is bent and biased in one direction, on the contact surface between the shield case 2 and the printed wiring board 1. . However, in this method, since the shim 4 is not fixed, it is difficult to tighten together with the shield case 2, and it is also difficult to fix the shim 4 at the front by soldering, etc. However, the number of parts increases due to the addition of shims.

<Purpose of the invention> The main purpose of the present invention is to improve the above-mentioned drawbacks.

<Description of Embodiments> Embodiments of the present invention will be described below in detail with reference to the drawings.

An embodiment of the present invention is shown in FIG. 2. First, small through holes 6 are provided at regular intervals around circuit parts that require electrical shielding in a printed wiring board 5. In addition, the tip of the shield case 7 is triangular in the vertical cross section so that the contact part (edge) with the printed wiring board 5 of the shield case 7, which is molded to cover this circuit part, is not flat but linear. (wedge-shaped) protrusion 8. The triangular vertex of this protrusion 8 is located at the center of the through hole 6.

Usually, when incorporating electronic components into the printed wiring board 5,
Electronic components are assembled by passing through a solder bath with the components inserted or mounted. At this time,
The solder is sucked up into the through hole 6, and the seat portion of the through hole is filled with solder 10 in a slightly raised state. When the shield case 7 is fixed to the printed wiring board 5 in this state with screws or the like, since the contact portion 8 is linear, the force of screwing is easily concentrated on the through hole 6.
It bites into the solder 10 that has swelled up and is attached in a state where the solder 10 is crushed, so the structure is such that electrical contact can be made reliably.

<Effect of the invention> Although the shield case 7 and the printed wiring board 5 do not contact each other in the areas between the through holes, this does not pose a practical problem if the distance between the through holes is kept small. . In other words, by providing the protrusion 8 on the contact part as in the present invention,
A radio device that can obtain electrical contact after absorbing some degree of deflection of the printed circuit board and manufacturing errors of the shield case, and does not require separate parts such as shims as in the past, and has a high shielding effect. It is possible to provide a shield structure.

[Brief explanation of the drawing]

Fig. 1a is a perspective view showing a conventional shield structure of an electronic circuit section, Fig. 1b is a perspective view showing a conventional shield structure and shim of an electronic circuit section, and Fig. 1c shows the assembled state of Fig. 1b. 2A is a perspective view showing the shield structure of the electronic circuit section of the present invention, and FIG. 2B is a sectional view of FIG. 2A when assembled. In the figure, 1, 5...printed wiring board, 2, 7
...Shield case, 3,9...Set screw, 4...
...Shim, 6...Through hole, 8...Protrusion, 1
0...Solder.

Claims (1)

[Scope of utility model registration request] A shield case having an electronic circuit section mounted on a printed wiring board, a plurality of through holes provided almost all around the electronic circuit section, and an edge that covers the electronic circuit section and corresponds to the through holes. and a protrusion having a triangular cross section provided on substantially the entire circumference of the edge, and solder slightly raised from the through hole and filled in the through hole, the protrusion being connected to the solder. A shield structure for an electronic circuit section, characterized in that the shield case covers and fixes the electronic circuit section so as to bite into the shield case.