JPH10322052A - Electronic component mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid waste to correspond to the projection amounts of mounting bolts and to prevent the mutual rotation of the bolts to enhance the workability of a cover removal, by a method wherein an electronic component is fixed in a case body by a plurality of component mounting screws to house the component in the case, and cover fixing screws are directly screwed in the heads of these component mounting screws. SOLUTION: First, a printed board 7 is coupled with a shielding case 6 using component mounting screws 4. That is, the board 7 is screwed in the case 6 by male thread parts using left-hand thread provided in the screws 4 and is clamped to the case 6. After the board 7 is mounted to this shielding case 6, the case 6 is sealed with a shielding cover 9. That is, the heads of the screws 4 which enabled the board 7 to fix in the case 6 are projected on the upper surface of the board 7. Cover fixing screws 10 are screwed in male thread parts using right-hand thread provided in the screws 4, and the cover 9 is clamped to the board 7 integrally with the case 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for storing an electronic component such as a printed circuit board in an electromagnetic wave shield, particularly in a wireless communication device.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional example of this type of mounting structure. The device housing in the radio unit includes a shield case 15 and a shield cover 16 for storing the internally mounted components in a state where the components are shielded from electromagnetic waves. The printed circuit board 18 is fastened and fixed to the shield case 15 by a plurality of mounting bolts 19 as shown in FIG.

The mounting bolt 19 has a male screw portion 21 formed of a regular screw (right-hand screw) formed continuously with one end of a hexagonal head 20. ) Is formed.

Accordingly, the printed circuit board 18 is first fastened and fixed to the shield case 15 by the mounting bolt 19. After the board is fixed, the cover set screw 23 is directly screwed into the female screw 22 of the head 20 projecting from the upper surface of the printed board 18 to fix and close the shield cover 16.

[0005] As shown in FIG. 5, another conventional structure is an installation structure of an electronic device described in Japanese Utility Model Laid-Open No. 6-11382. In this case, the shape of the mounting bolt 27 shown in FIG. 7 is such that a male screw portion 24 is formed on one end of a head 26 having a hexagonal cross section by a normal screw (right-hand screw), and a reverse screw (left-hand screw) is formed on the other end. The male screw portion 25 is formed.

First, the printed circuit board 28 is fastened and fixed to the shield case 29 by a male screw portion 25 formed by a reverse screw (left-hand screw) of the mounting bolt 27. Next, the cover lock nut 31 is screwed onto the male screw portion 24 formed by a positive screw (right-hand screw) to fix the shield cover 30 and close the shield case 29.

[0007]

However, any of the mounting bolts 19 and 27 shown in these two conventional examples has the following problems to be solved.

A first problem is that both ends are male threads, one of which is a positive thread (right-hand thread) and the other is a reverse thread (left-hand thread). That is, when both ends are male screws, the printed circuit board can be fixed inside. However, when the shield cover is fixed, since the shield cover is fixed by the nut, the protrusion amount of the tip of the female screw becomes large, and there is a problem that the mounting area in the width direction of the unit becomes large.

A second problem is that when a cover set screw for fixing the shield cover is removed, there is a disadvantage that the mounting bolt in the shield case is loosened at the end of the cover set screw. That is, one of the screw shapes of the mounting bolts in the shield case forms a male screw that becomes a positive screw (right-hand screw), and the other forms a female screw that becomes a positive screw (right-hand screw). That is, since both the male screw and the female screw are positive screws (right-handed screw), the removal force when removing the cover set screw is greater than the fastening force of the mounting bolt fixing the printed circuit board. . Therefore, the mounting bolt is loosened before the cover set screw.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a housing for an electronic component such as a printed circuit board, which is used when an electronic component such as a printed circuit board is housed in an equipment housing and fastened and fixed with mounting bolts. It is an object of the present invention to provide an electronic component mounting structure in which a case is prevented from being large-sized, the mounting bolts are prevented from rotating together, and the cover removal workability is improved.

[0011]

According to the electronic component mounting structure of the present invention, an electronic component is fixed and housed in a casing case such as a shield case with a plurality of component mounting screws. Screw the cover fixing screw directly into the part to secure the case cover with a shield cover or the like to the housing case and close it.The component mounting screw is connected to the male screw part with the reverse screw formed in the head. The cover has a female screw portion formed by a regular screw into which a cover fixing screw is screwed.

In this case, in the component mounting screw, the nominal diameter of the male screw portion is formed larger than the nominal diameter of the female screw portion. In addition, it is possible to prevent loosening due to co-rotation of the component mounting screws, and the shield cover can be easily and quickly removed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred embodiment of an electronic component mounting structure according to the present invention, a case of a printed circuit board used for a wireless communication device will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view of a radio unit 5 constituting a part of a high-density mounting unit for mounting a printed circuit board by shielding electromagnetic waves. A shield case 6 is provided for internally mounting the printed circuit board 7 by shielding the printed circuit board 7 with electromagnetic waves. In order to seal the printed circuit board 7 after mounting, a shield cover 9 is fastened to the shield case 6 and closed.

FIG. 2 shows a component mounting screw 4 as a gist in the mounting structure of the present embodiment. The component mounting screw 4 has a head portion 1 having a hexagonal cross section in preparation for a tightening operation by a screwdriver, and a male screw portion 2 formed by a reverse screw (left-hand screw) is formed continuously with one end of the screw. The head 1 is formed with a female thread 3 that is smaller than the nominal diameter of the male thread 2 and is formed by a positive thread (right-hand thread).

As shown in FIG. 1, the printed circuit board 7 is first connected to the shield case 6 using the component mounting screw 4. That is, the printed circuit board 7 is screwed from above with the male screw portion 2 of the component mounting screw 4 formed by the left-hand thread, and fastened to the shield case 6.

After the printed circuit board 7 is attached to the shield case 6, the shield case 9 is hermetically sealed by the shield cover 9.

That is, the head 1 of the component mounting screw 4 for fixing the printed circuit board 7 to the shield case 6 by fastening is:
It protrudes from the upper surface of the printed circuit board 7. The cover fixing screw 10 is screwed into the female screw portion 3 formed by the right-hand thread provided in the head 1 of the component mounting screw 4, and the shield cover 9 is fastened integrally with the shield case 6 on the printed circuit board 7.

At the time of mounting such a shield cover, the nominal diameter of the male screw portion 2 of the component mounting screw 4 is equal to that of the female screw portion 3.
It is larger than the nominal diameter. Therefore, even when the cover fixing screw 10 is screwed into the female screw portion 3 of the right-hand thread to attach the shield cover 9, the tightening force (screw torque)
Is small, the component mounting screw 4 does not loosen.

Conversely, when removing the shield cover 9,
The part where the printed circuit board 7 is fastened is the component mounting screw 4
, The component mounting screw 4 tends to rotate in the opposite direction to the torque applied in the direction in which the fixing screw 10 of the shield cover 9 is loosened. As a result, a torque acts on the component mounting screw 4 in a further tightening direction, and the cover fixing screw 10 can be easily removed from the shield cover 10. In this manner, the work of removing the shield cover 10 can be performed easily and quickly.

On the other hand, FIG. 3 shows a component mounting screw 27 of another embodiment instead of the component mounting screw 4 of the above embodiment.
Is shown. In this case, a male screw portion 12 serving as a reverse screw is formed at one end of the cylindrical head 11, and a female screw portion 13 serving as a positive screw (right-hand screw) is formed at the other end surface. Furthermore, the width is 1.2 mm in the radial direction, and the search is 1 mm.
About 14 grooves are formed.

[0022]

As described above, the mounting structure of an electronic component according to the present invention is such that the mounting amount of a component mounting screw for fixing an electronic component such as a printed circuit board to a casing case, for example, a shield case, after screwing, is head. It is possible to reduce the size of the housing case because it requires only a small part.

Further, according to the present invention, it is possible to prevent a component mounting screw fastening a printed circuit board from being loosened even if the cover fixing screw is loosened when the case cover, for example, a shield cover is removed. The removal operation can be performed easily and quickly to enhance the workability.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an electronic component mounting structure according to the present invention.

FIG. 2 is a partial cross-sectional configuration diagram showing a component mounting screw for fixing an electronic component, which is a main part of the present embodiment.

FIG. 3 is a partial cross-sectional view showing a component mounting screw according to another embodiment.

FIG. 4 is an exploded perspective view showing a conventional mounting structure.

FIG. 5 is an exploded perspective view showing another conventional mounting structure.

6 is a structural view of a part cross section of a component mounting bolt used in the conventional example of FIG.

FIG. 7 is a configuration diagram of a part cross section of a component mounting bolt used in the conventional example of FIG.

[Explanation of symbols]

 1 Hexagonal head of component mounting screw 2 Male screw to be reverse screw 3 Female screw to be positive screw 4 Component mounting screw 5 Radio unit 6 Shield case 7 Printed circuit board 8 Female screw to be reverse screw 9 Shield cover 10 Cover fixing screw 11 Cylindrical head 12 Male screw part which becomes reverse screw 13 Female screw part which becomes positive screw 14 Groove

Claims (5)

[Claims] An electronic component is fixed and housed in a housing case with a plurality of component mounting screws, and a cover fixing screw is screwed directly into a head of the component mounting screw to thereby attach the case cover to the housing case. An electronic component mounting structure that is fixed and closed to the electronic component, wherein the component mounting screw has a male screw portion formed by a reverse screw connected to the head, and the cover fixing screw is screwed into the head. A mounting structure for an electronic component, comprising a female screw portion formed by a mating positive screw. 2. The electronic component mounting structure according to claim 1, wherein a nominal diameter of the male screw portion is formed larger than a nominal diameter of the female screw portion. 3. The electronic component mounting structure according to claim 1, wherein when the reverse screw forming the male screw portion is a left-handed screw, the positive screw forming the female screw portion is a right-handed screw. . 4. A cross-sectional shape of the head is polygonal or circular, and in the case of a circular cross-section, a groove having a concave cross-section is formed in an end face of the head for operating a screwdriver. The mounting structure for an electronic component according to claim 1. 5. The electronic device according to claim 1, wherein said housing case and said case cover closing said housing enable electromagnetic wave shielding, and said electronic component mounted inside is a printed circuit board. The mounting structure of the electronic component according to 1.