JP2003051692A - Method for mounting shielding box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for mounting a shielding box, by which the shielding box can be surely fixed to a printed wiring board, even when a small securing part is used. SOLUTION: First, the joint surface 12a of a securing part 10 is sucked and lifted up by an automatic mounter and is fixed at the specified position on the side wall 22 of a shielding box 20. Then, the upper plate 21 of the shielding box 20 to which the securing part 10 is fixed is sucked and the shielding box 20 is placed at the specified position of a printed wiring board by the automatic mounter, and the joint surface 12a is soldered by reflow soldering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a shield box that covers electronic components mounted on a printed wiring board and shields electromagnetic waves.

[0002]

2. Description of the Related Art Conventionally, for example, a shield box in which side walls are provided upright from four sides of a rectangular top plate is mounted on a printed wiring board so as to cover electronic components, and electromagnetic waves are shielded. There is.

For example, Japanese Patent Publication No. 3-30317 discloses that
A small electromagnetic shield device is disclosed. In this technique, a U-shaped spring groove is mounted on a printed wiring board, and then the side wall of the shield box is inserted into the mounted spring groove to sandwich the shield box.

Further, for example, Japanese Utility Model Laid-Open No. 61-111198 discloses a shield case including a frame body on which mounting legs for a printed wiring board are vertically provided, and a lid body covering an open upper portion of the frame body. ing. In this case, the lid is fixed by mounting the frame on the printed wiring board and then fitting the lid to the frame.

[0005]

However, in any of the above-mentioned techniques, the components mounted on the printed wiring board, that is, the U-shaped spring groove in the former case and the frame body in the latter case are relatively large. The occupied area on the printed wiring board becomes large. This is not preferable from the viewpoint of downsizing and weight saving of electronic devices in recent years.

As a method for solving this, it is conceivable to fix the shield box by using a small fixing component. Specifically, the U-shaped spring groove in the above-mentioned technology is slightly shorter than the length of the side wall, but is a fixed part (eg, a spring groove) that is sufficiently shorter than this.
And partially sandwich the side wall. If the shield box becomes large, the side wall may be fixed with a plurality of fixing parts.

With this arrangement, the area and weight of the printed wiring board can be reduced. Further, unlike the technique of the above-mentioned publication, such a fixed component is not prepared in accordance with the shield box and has high versatility, which is advantageous in terms of cost.

However, when the size of the fixed component is reduced, mounting accuracy on the printed wiring board becomes a problem. In particular, when one side wall is sandwiched by a plurality of fixing parts, it is necessary to mount the fixing parts accurately on a straight line. In addition, since electronic components are downsized as a result of downsizing of electronic devices, high mounting accuracy is required in that sense as well.

However, when the small fixed parts are individually soldered, it is difficult to improve the mounting accuracy. In particular, when one side wall is sandwiched by a plurality of fixed parts, the plurality of fixed parts cannot be accurately arranged on a straight line on the printed wiring board. If the mounting accuracy becomes low, the shield box cannot be attached after that.

The present invention has been made in order to solve the above-mentioned problems, and a shield box capable of reliably fixing the shield box to the printed wiring board even when a small fixing component is used. The purpose is to provide an implementation method.

[0011]

SUMMARY OF THE INVENTION The present invention is a method of mounting a shield box having a top plate and a side wall portion connected from an end of the top plate on a printed wiring board. The side wall portion may be formed by bending from the upper surface plate, or may be configured separately from the upper surface plate as a frame body fitted to the upper surface plate as the lid body. This shield box is mounted on a printed wiring board to cover the electronic components on the printed wiring board with the top plate and the side wall portions to shield electromagnetic waves.

In the present invention, a fixed component having a joint portion having a joint surface to be soldered to a printed wiring board is used for mounting the shield box. Here, in particular, the present invention first attaches the fixed component to the side wall portion by a fixing portion provided on at least one of the fixed component and the side wall portion, and then attaches the shield box to which the fixed component is attached to the printed wiring board. It is characterized in that it is placed at a predetermined position and the joint surface of the fixed component is soldered. It is possible to adopt a clip-like structure for the fixing portion here.

If a fixed component, which is a component for mounting the shield box, is previously mounted on the printed wiring board as in the conventional case, mounting accuracy is required due to the relationship with the shield box. On the other hand, in the present invention, a fixed component is attached to the shield box in advance, the shield box with the fixed component attached is placed on the printed wiring board, and the fixed component is soldered. Therefore, no matter how small a fixed component is used, even if one side wall is sandwiched by two or more fixed components, the fixed component is mounted according to the side wall of the shield box. That is, even when the side wall is to be sandwiched by a plurality of fixed parts, the fixed part is soldered while being attached to the side wall, so that the fixed part is accurately soldered on a straight line.

If the joint surfaces of a plurality of fixed parts previously attached to the shield box are not on a plane, some fixed parts may not be soldered sufficiently. Therefore, as described in claim 2, after the fixed parts are attached to the side wall portion, the joint surfaces of the plurality of fixed parts are pressed against the flat surface to align the joint surfaces so as to be located on one plane, It is conceivable to place the shield box at a predetermined position on the printed wiring board. As a result, the joint surfaces of the plurality of fixed parts are on the same plane, so that each fixed part is reliably soldered.

For example, when mounting the shield box at a predetermined position on the printed wiring board, it is conceivable that the upper surface plate of the shield box is sucked by an automatic mounting machine. Therefore, prior to the mounting operation, as shown in claim 3, the upper surface plate of the shield box to which the fixed parts are attached is sucked and lifted by the automatic mounting machine to make the joint surfaces of the plurality of fixed parts flat. You just have to press it.

By using the upper surface plate of the shield box as the suction surface in this way, the work process of aligning the joint surfaces of the fixed parts can be automated. This can improve the mounting efficiency. By the way, from the viewpoint of improving the mounting efficiency, as described in claim 4, the joint surface of the fixed component may be sucked by an automatic mounting machine and attached to the side wall portion of the shield box. In this case, the shield box is arranged so that the side wall portion is located above, the joint surface of the fixed component is sucked and lifted, and in this state, the shield box is attached to a predetermined position on the side wall portion of the shield box. As a result, the process of attaching the fixed component is automated, which contributes to further improvement in mounting efficiency.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show a fixed component 10 used in the mounting method of the embodiment. FIG. 1A is a plan view of the fixed component 10, and FIG.
[Fig. 1] is a front view of the fixed component 10 as seen from the direction of the arrow indicated by the symbol A in Fig. 1 (a). On the other hand, FIG. 2A is a side view of the fixed part 10, and FIG. 2B is a side view of FIG.
FIG.

The fixed part 10 has a rectangular joint portion 12.
And a side portion 13 that is erected by bending both sides in the lateral direction of the joint portion 12, and a side portion 13 that is inclined toward the inside of the side portion 13.
And the end portion 15 bent outward from the slant portion 14 that is bent at the center portion in the lateral direction.
It has and. Here, a projecting piece 12b having a slightly narrow width is formed at the end portion in the longitudinal direction of the joint portion 12. The lower surface of the joint portion 12 including the lower surface of the projecting piece 12b is the joint surface 12a to be soldered to the printed wiring board.

A substantially U-shaped cut 16 is formed in the central portions of the side portion 13 and the inclined portion 14, and the inner portion of the cut 16 is substantially perpendicular to the joint portion 12 and the central portion in the lateral direction. Is bent at the connecting portion on the side of the end portion 15 so that they are exactly aligned with each other. This portion is the fixed portion 11, and a convex portion 11a protruding toward the other fixed portion 11 is formed on one fixed portion 11 by drawing, and the convex portion 11a is stored in the other fixed portion 11. A storage hole 11b having a size to be formed is formed.

FIG. 3 shows a shield box 20 used in the mounting method of the embodiment. FIG. 3A is a plan view of the shield box 20, and FIG.
It is a side view of the shield box 20 seen from the direction of the arrow shown by the symbol B in (a). In FIG.3 (b), it has shown that one part was broken.

The shield box 20 is provided with a rectangular top plate 21 and side wall parts 22 provided upright from each end of the top plate 21. The side wall portion 22 is composed of four side walls that are provided upright from the end portion of the upper surface plate 21, and the shield box 20 has a lid shape having no surface facing the upper surface plate 21. Hereinafter, the side facing the upper surface plate 21 will be referred to as the “opening side”. Therefore, by fixing this opening side as the printed wiring board side, the shield box 20 covers the electronic components mounted on the printed wiring board with the top plate 21 and the side wall portions 22 to shield electromagnetic waves.

A component for fixing such a shield box 20 on the printed wiring board is the fixing component 10 described above. The fixed part 10 has a predetermined position on the side wall 22 of the shield box 20 (a position indicated by a chain double-dashed line in FIG. 3).
And the shield box 20 is mounted on the printed wiring board.

Next, a mounting method in this embodiment will be described. In this embodiment, the shield box 20 is mounted by the following procedures (1) to (4). First, the fixed component 10 is lifted by an automatic mounting machine by adsorbing the joining surface 12a of the fixed component 10 and attached to a predetermined position (position indicated by a chain double-dashed line in FIG. 3) of the side wall portion 22 of the shield box 20. Go. Specifically, the side wall portion 22 is attached so as to be pushed into the joint of the center portion in the lateral direction of the fixed component 10. At this time, as shown in FIG. 4A, the fixed component 10 is elastically deformed outward with the side portion 13 and the inclined portion 14 as the center, and the reaction force thereof causes the fixed portion 1
1 holds the side wall portion 22. In particular, since the convex portion 11a is formed on one side of the fixed portion 11, the convex portion 11a
Presses against each other and securely holds the side wall portion 22.

Then, the shield box 20 to which the fixed component 10 is attached at a predetermined position on the side wall portion 22 is lifted by adsorbing the upper surface plate 21 with an automatic mounting machine. In this state, the joint surface 12a of the fixed component 10 is pressed against the flat surface, and the heights of the joint surface 12a of the fixed component 10 are made uniform. That is, the joint surfaces 12a of the six fixed components 10 attached to the shield box 20 are positioned on one plane.

Thereafter, the shield box 20 to which the fixed component 10 is attached is placed at a predetermined position on the printed wiring board as shown in FIG. A pattern corresponding to the joint surface of the fixed component 10 is formed on the printed wiring board, and cream solder is previously supplied to the pattern. As a result, the fixed component 10 attached to the shield box 20 is temporarily fixed.

Finally, soldering by reflow soldering is performed. Thereby, the joint surface 1 of the fixed component 10
2a is soldered to the pattern of the printed wiring board. Next, the effect exerted by the mounting method of this embodiment will be described. Conventionally, a U-shaped spring groove or the like corresponding to the fixed component 10 of the present embodiment is soldered to the pattern of the printed wiring board first, and the shield box is attached to the soldered component. For this reason, the fixed parts could not be downsized. In particular, in the case of fixing one side wall of the shield box with a plurality of fixing parts, it becomes necessary to arrange the fixing parts on a straight line, which requires high mounting accuracy.

On the other hand, in this embodiment, first, the fixed component 10 is attached to the side wall portion 22 of the shield box 20 (described above), and then the shield box 20 to which the fixed component 10 is attached is mounted on the printed wiring board. The fixed surface 10a of the fixed part 10 by reflow soldering.
Is soldered to the pattern on the printed wiring board (above and above). As a result, the fixed component 10 is soldered at a position matching the shield box 20 to be attached, and the problem of mounting accuracy required by mounting only the fixed component 10 first can be avoided. . For example, the longitudinal side walls forming the side wall portion 22 are attached by two fixing parts 10, respectively. According to the present embodiment, the fixing part 10 is soldered on a straight line which is aligned with the side wall part 22. You can

Further, in this embodiment, the fixed component 1 is mounted on the flat surface.
The joint surface 12a of 0 is pressed so that the joint surfaces 12a of the six fixed components 10 attached to the shield box 20 are located on one plane (above). As a result, when the shield box 20 is placed on the printed wiring board, all of the joint surfaces 12a come into contact with the cream solder supplied to the pattern of the printed wiring board, and all the fixed components 10 are reliably soldered. To be done.
Furthermore, this procedure is performed by the upper plate 21 of the shield box 20.
Is picked up by an automatic mounting machine and the shield box 20 is lifted. That is, it is automatically performed prior to the subsequent mounting operation of the shield box 20 on the printed wiring board. By thus using the upper surface plate 21 of the shield box 20 as the suction surface, the work process of aligning the joint surface 12a of the fixed component 10 is also automated, and the mounting efficiency can be improved.

Furthermore, in this embodiment, the joint surface 12a is
Then, the fixed component 10 is lifted by the automatic mounting machine by sucking and is attached to the predetermined position (the position indicated by the chain double-dashed line in FIG. 3) of the side wall portion 22 of the shield box 20 (above). As a result, the process of attaching the fixed component 10 is automated, which contributes to further improvement in mounting efficiency.

Further, since the convex portion 11a is formed on one of the fixed portions 11 of the fixed component 10, the shield box 20 can be securely sandwiched and fixed by the convex portion 11a. Further, the shield box 20 can be removed while the fixed component 10 is soldered.

In the method of this embodiment, it is possible to provide the shield box 20 in which the fixed part 10 is attached to the side wall portion 22, and at this time, the reflow process by the automatic mounting machine is performed on the provided side. The shield box 20 can be easily mounted on the printed wiring board by soldering.

As described above, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the gist of the present invention. (A) In the above-described embodiment, as shown in FIG. 4A, the convex portion 11a of the fixed portion 11 is in pressure contact with the side wall portion 22 to sandwich the side wall portion 22.

On the other hand, the convex portion 11a may not be provided on the fixed portion 11, and the side wall 22 may be sandwiched between the inner side surfaces of the fixed portion 11. Further, the side wall 22 is formed with a mounting hole 22a that fits into the convex portion 11a, and the convex portion 1
1a may be fitted in the mounting hole 22a. Figure 4
As shown in (b).

Needless to say, when the mounting hole 22a is formed in this manner, the fixed component 10 is accurately positioned at a predetermined position on the side wall 22. However, even if the mounting hole 22a is not formed in the side wall 22 as in the above embodiment, the fixing component 10 can be accurately mounted at a predetermined position on the side wall 22 by using a gauge.

(B) In the above embodiment, the fixing portion 11 of the fixing component 10 is formed by making the notch 16 in the central portion of the side portion 13 and the inclined portion 14. However, the fixed part is not limited to this as long as it holds the side wall of the shield box.

For example, as a fixing component 40 shown in the front view of FIG. 6 (a), the fixing portion 41 is formed by aligning the entire side walls bent from the ends of the joining portion 42 at the central portion in the lateral direction. Good. Also in this case, it is conceivable to form the convex portion 41a on the fixed portion 41, for example.

Further, for example, like a fixed part 50 shown in the front view of FIG. 6B, one end of the joint 52 is bent substantially vertically to form one fixed part 53, and the other end is joined to the other fixed part 53. You may form the other fixed part 54 in which the convex part 54a was formed so that it might match with the fixed part 53. In this configuration, since the joint portion 52 does not project to the one fixing portion 53 side, the area occupied by the fixing component 50 on the one fixing portion 53 side is
Can be made smaller.

(C) In the above-described embodiment, the fixed component 10 has the fixed portion 11, and the side wall portion 22 is sandwiched and fitted. On the other hand, a shield box 30 as shown in FIG. 7A may be adopted. The shield box 30 is formed by folding back an edge portion of the side wall portion 32 at a predetermined position to form a fixing portion 34 having a U-shaped cross section.
For such a shield box 30, FIG.
A fixing component 60 having an L-shaped cross section and a convex portion 61a as shown in FIG. 7B is adopted, or a fixing component 70 having a T-shaped cross section and having a convex portion 71a as shown in FIG. 7C is used. It may be adopted. In this case, the fixed part 6
The fixed portions 34 of the side wall portion 32 sandwich and sandwich 0 and 70.

(D) In the above embodiment, the shield box 20 having the rectangular upper surface portion 21 was used, but the shape of the shield box may be appropriately selected depending on the arrangement of electronic components on the printed wiring board side. For example, a shield box 80 as shown in FIG. 8 may be adopted. Here, the side wall portion 8 is formed by the six side walls standing from the upper surface portion 81.
2 is formed.

[Brief description of drawings]

FIG. 1A is a plan view showing a fixing part of an embodiment, and FIG. 1B is a front view showing a fixing part of the embodiment.

FIG. 2A is a side view showing a fixing component of the embodiment, and FIG. 2B is a sectional view taken along line AA of FIG.

FIG. 3A is a plan view showing a shield box of the embodiment, and FIG. 3B is a side view showing the shield box of the embodiment.

FIG. 4 is an explanatory view showing a state in which a fixed component is attached to a side wall portion of a shield box.

FIG. 5 is an explanatory diagram showing a state in which a shield box is mounted on a printed wiring board together with fixed components.

FIG. 6 is a front view showing a fixing component of another embodiment.

FIG. 7 is an explanatory view showing a shield box and a fixing component of another embodiment.

FIG. 8 is an explanatory diagram showing an appearance of a shield box of another embodiment.

[Explanation of symbols]

10, 40, 50, 60, 70 ... Fixed parts 11, 41, 53, 54 ... Fixed part 11a, 41a, 54a, 61a, 71a ... Convex portion 11b ... storage hole 12, 42, 52 ... Joint 12a ... Bonding surface 12b ... protrusion 13 ... Side 14 ... Inclined part 15 ... Edge 16 ... notch 20, 30, 80 ... Shield box 21, 81 ... Top plate 22, 32, 82 ... Side wall part 22a ... Mounting hole

Claims (4)

[Claims] 1. An upper surface plate and a side wall portion connected to an edge portion of the upper surface plate, and mounted on the printed wiring board, whereby the upper surface plate and the side wall portion are provided on the printed wiring board. A mounting method for mounting a shield box that covers an electronic component to shield electromagnetic waves on the printed wiring board using a plurality of fixed components, wherein the fixed component has a joint surface to be soldered to the printed wiring board. Having a joint formed, first of all, the fixing part is attached to the side wall part by a fixing part provided on at least one of the fixing part or the side wall part, and then the fixing part is attached. A method for mounting a shield box, comprising placing the shield box at a predetermined position on the printed wiring board and soldering a joint surface of the fixed component. 2. The mounting method according to claim 1, wherein after the fixed parts are attached to the side wall portions, the joint surfaces of the plurality of fixed parts are pressed against a flat surface so that they are positioned on one plane. A method for mounting a shield box, which comprises placing the shield box at a predetermined position on the printed wiring board after aligning the joint surfaces as described above. 3. The mounting method according to claim 2, wherein the upper surface plate of the shield box to which the fixed parts are attached is suctioned and lifted by an automatic mounting machine, and the joint surfaces of the plurality of fixed parts are flattened. A method for mounting a shield box, which is characterized by pressing against a surface. 4. The mounting method according to claim 1, wherein the fixed component is sucked at the joint surface by an automatic mounting machine,
A method for mounting a shield box, characterized in that the shield box is attached to a side wall portion of the shield box.