JP2013251491A - Electromagnetic shield structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic shield structure for facilitating positioning work of a shield case and a clip, and work for pushing an end of the shield case into the clip.SOLUTION: A recessed part 31D is provided at a bottom edge of a side wall part 3D of a shield case 3. The recessed part 31D is located at a position where an elastic piece 5B can be brought into contact with an inner surface of the recessed part 31D (referred to a selection figure (b).). When the shield case 3 is further made relatively close to a printed wiring board 7 with elastic pieces 5B, 5C in contact with inner surfaces of recessed parts 31A to 31H, the elastic pieces 5B, 5C are caused to slide along the inner surfaces of the recessed parts 31A to 31H, and the recessed part 31D consequently guides the elastic pieces 5B, 5C to a position at which the elastic pieces 5B, 5C can hold the shield case 3 while gradually increasing deformation volume of the elastic pieces 5B, 5C.

Description

  The present invention relates to an electromagnetic wave shield structure that blocks electromagnetic waves radiated from an electronic component mounted on a printed wiring board or electromagnetic waves arriving at an electronic component mounted on a printed wiring board around the electronic component.

  Conventionally, as this kind of electromagnetic wave shield structure, what was indicated, for example in the following patent documents 1 and 2 is proposed. Each of these electromagnetic wave shield structures has a structure including a clip that is surface-mounted on a printed wiring board and a shield case that is held by the clip.

  According to such an electromagnetic wave shield structure, the shield case is fixed on the printed wiring board, and the conductor pattern (for example, a portion having a ground potential) provided in the printed wiring board and the shield case are electrically connected via the clip. Can be connected.

JP 2003-51690 A JP 2005-332953 A

However, the electromagnetic shielding structures described in Patent Documents 1 and 2 still have room for improvement in terms of the following points.
That is, in the case of the electromagnetic wave shield structure described in Patent Documents 1 and 2, the shield case is attached to the clip by inserting the end portions of the side walls provided in the shield case between the pair of elastic pieces provided in the clip. It has a sandwiched structure. However, it is not always easy to insert a part of the shield case between the elastic pieces of this type. In particular, the side walls of the shield case are provided at the same time for a plurality of clips arranged on each of the four sides of the shield case. The operation | work which inserts the edge part of a part is not easy.

  In particular, in recent years, electronic devices have become smaller and thinner, and this type of electromagnetic shielding structure itself needs to cope with smaller and thinner devices, so the size of shield cases and clips has become extremely small. Yes. For this reason, it is not easy to align the position of the shield case with respect to the clip that has been mounted on the surface in advance, and if the shield case is pressed against the clip without proper alignment, the clip will be deformed. There was also a fear of inviting.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide an electromagnetic wave shield that facilitates the alignment work of the shield case and the clip and the work of inserting the end of the shield case into the clip. To provide a structure.

Hereinafter, the configuration employed in the present invention will be described.
The electromagnetic wave shield structure of the present invention is attached to a position covering an electronic component mounted on a printed wiring board, thereby shielding a electromagnetic wave radiated from the electronic component or an electromagnetic wave arriving at the electronic component, The shield case is held on the printed wiring board by being fixed on the printed wiring board by soldering and being pressed against the shield case with an elastic piece that is elastically deformed in contact with the shield case. At least one clip, and when the shield case is mounted on the printed wiring board, the shield case is disposed perpendicular to the front and back surfaces of the printed wiring board at a position surrounding the periphery of the electronic component. An end that is on the side of the printed wiring board on the side wall. Are provided with at least one of a concave portion formed by recessing the outer surface of the side wall portion inward and a concave portion formed by recessing the inner surface of the side wall portion outward. The concave portion causes the shield case to contact the clip disposed at a predetermined position on the printed wiring board with the end portion of the shield case facing the printed wiring board side. The elastic piece is provided at a position where it can be brought into contact with the inner surface of the recess, and the shape of the inner surface of the recess is made so that the elastic piece is brought into contact with the inner surface of the recess. When the shield case is further moved relatively closer to the printed wiring board from a state where the elastic piece is moved, the deformation amount of the elastic piece is gradually increased by sliding the elastic piece along the inner surface of the recess. While Characterized in that in the serial elastic piece is the elastic piece and the guide can shape into holdable a position of the shield case.

  According to the electromagnetic wave shielding structure configured in this way, the above-described recess is provided on the shield box side, and the elastic piece provided in the clip can be brought into contact with the inner surface of the recess. If it is in such a state, the position of a clip and a shield box can be appropriately matched on the basis of the position of an elastic piece and a recessed part. Moreover, since it is not necessary to elastically deform the elastic piece at this stage, there is no possibility that an excessive load is applied to the clip.

  Further, when the positions of the elastic piece and the concave portion are aligned in this way, the shield case is relatively displaced toward the printed wiring board. At this time, the elastic piece slides along the inner surface of the recess, and the elastic deformation of the elastic piece proceeds along with the sliding, and the amount of deformation gradually increases. Therefore, unlike the conventional technique in which the end face of the shield case is forcedly pushed between a pair of elastic pieces, the elastic piece can be smoothly elastically deformed, and the work of attaching the shield case on the printed wiring board is easy. Become.

  Furthermore, when the end portion of the shield box has a flat plate shape without a recess, the flat plate portion is easily displaced in a direction parallel to the flat plate portion, but in the case of the present invention, an elastic piece is provided on the inner surface of the recess portion. The contact makes it difficult for the recess to be displaced in the direction in which the elastic piece deviates from the recess. For this reason, this also contributes to prevention of displacement of the shield case.

  By the way, in the electromagnetic wave shield structure of the present invention, any number of elastic pieces may be provided for one clip, and any number of clips may be combined for one shield box. To give a more specific example, for example, one clip has a single elastic piece, and the elastic piece provided in each of the plurality of clips cooperates or the elastic piece provided in the clip. It is preferable that the shield case is held by the cooperation of other members.

  In the case of such a clip having a single elastic piece, it becomes difficult for one clip to hold the shield case alone, but two or more clips are arranged at predetermined positions according to the shape of the shield case. By doing so, the shield case can be held in such a manner that the shield case is sandwiched between the elastic pieces included in each of the two or more clips.

  Alternatively, if the shield case is pressed against another member, or the shield case is hooked on another member, the movement of the shield case is restricted by the other member so that it can move only in a predetermined direction. By restricting the movement in the predetermined direction with one or more clips, the shield case can be held so as not to move from the predetermined position. That is, when cooperating with other members, the shield case can be held by using only one clip.

  On the other hand, in the clip of the present invention, for example, one clip has a plurality of elastic pieces, and the elastic pieces provided in each of the plurality of clips cooperate with each other, or the elastic pieces provided in the clip and others. The shield case may be held by cooperating with the member or by cooperating with the plurality of elastic pieces included in one clip.

  Even in the case of such a clip having a plurality of elastic pieces, by arranging two or more clips in a predetermined position according to the shape of the shield case, the two or more clips are provided between the elastic pieces respectively provided. The shield case can be held in the form of sandwiching the shield case.

  Alternatively, if the shield case is pressed against another member, or the shield case is hooked on another member, the movement of the shield case is restricted by the other member so that it can move only in a predetermined direction. By restricting the movement in the predetermined direction with one or more clips, the shield case can be held so as not to move from the predetermined position.

  Furthermore, depending on the positional relationship between the plurality of elastic pieces provided in one clip, the shield case can be held in such a manner that the shield case is sandwiched between the plurality of elastic pieces. That is, when one clip is provided with a plurality of elastic pieces, whether or not the shield case can be sandwiched between the plurality of elastic pieces is arbitrary, even if one clip can hold the shield case alone, A plurality of clips may cooperate to hold the shield case.

  More specifically, for example, the clip includes, as the elastic piece, a first elastic piece that is in pressure contact with the outer surface of the side wall portion, and a second elastic piece that is in pressure contact with the inner surface of the side wall portion. The first elastic piece and the second elastic piece are formed at positions that do not overlap each other when viewed from a direction orthogonal to the inner surface and the outer surface of the side wall portion, and in the shield case, a position corresponding to the first elastic piece. Is formed with a first concave portion having a shape in which the outer surface of the side wall portion is recessed inward, and the inner surface of the side wall portion is recessed outwardly at a position corresponding to the second elastic piece. An example is a structure in which a second recess having an irregular shape is formed.

  In the case of the electromagnetic shielding structure having such a structure, the single clip includes the first elastic piece and the second elastic piece, and these elastic pieces are in pressure contact with the outer surface and the inner surface of the side wall portion. The shield box can be appropriately held with a small number of clips, rather than a clip having a pressure contact piece pressed against either the outer surface or the inner surface.

  Further, since the first elastic piece and the second elastic piece are formed at positions that do not overlap each other when viewed from the direction orthogonal to the inner surface and the outer surface of the side wall portion, the first elastic piece and the second elastic piece are formed in association with such positions. The first recess and the second recess are also formed at positions that do not overlap each other when viewed from the direction orthogonal to the inner surface and the outer surface of the side wall portion. Therefore, even if there is a convex part on the back side due to the provision of the first concave part, it is not necessary to provide the second concave part at that position, and because the second concave part is provided. Even if a convex portion is formed on the back side, the first concave portion does not have to be provided at that position, and the first concave portion and the second concave portion can be provided at positions that do not interfere with each other.

(A) is a perspective view which shows the electromagnetic wave shield structure of 1st embodiment, (b) is a perspective view which shows the state which isolate | separated the shield case and the clip in the electromagnetic wave shield structure shown to Fig.1 (a). (A) is the perspective view which looked at the clip of 1st embodiment from the upper left front, (b) is the perspective view which looked at the clip of 1st embodiment from the lower right back. (A) is a plan view showing the clip of the first embodiment, (b) is a front view showing the clip of the first embodiment, (c) is a bottom view showing the clip of the first embodiment, and (d) is the first view. The right view which shows the clip of one Embodiment. (A) is an expanded sectional view in the cut surface shown by the AA line in FIG.3 (b), (b) is an enlarged view of the B section shown in FIG.4 (a). FIG. 5A is a plan view of the shield case of the first embodiment, FIG. 5B is a cross-sectional end view taken along the line DD in FIG. 5A, and FIG. 5C is FIG. FIG. 5 is a cross-sectional end view of the portion indicated by line EE. (A)-(d) is explanatory drawing which showed the state in which the shield case (shield case of 1st embodiment) with a recessed part was attached to a clip in steps, (e)-(h) is the shield case without a recessed part Explanatory drawing which showed the state in which (conventional shield case) was attached to a clip in steps. (A) is a perspective view which shows the electromagnetic wave shield structure of 2nd embodiment, (b) is a perspective view which shows the state which isolate | separated the shield case and the clip in the electromagnetic wave shield structure shown to Fig.7 (a). (A) is the perspective view which looked at the clip of 2nd embodiment from the upper left front, (b) is the top view which shows the clip of 2nd embodiment, (c) is the front view which shows the clip of 2nd embodiment, ( d) The bottom view which shows the clip of 2nd embodiment. (A) is a perspective view showing an example of an electromagnetic shielding structure different from the example shown in FIG. 1 (a), and (b) is a diagram in which the shielding case and the clip are separated in the electromagnetic shielding structure shown in FIG. 7 (a). The perspective view which shows the state. 2A is a perspective view of a clip different from the example shown in FIG. 2A as viewed from the upper left front, and FIG. 2B is a clip different from the examples shown in FIG. 2A and FIG. 8A. The perspective view which looked at from the upper left front. (A) is a top view which shows an example of the electromagnetic wave shield structure in which the arrangement direction of a clip differs from 2nd embodiment, (b) is another electromagnetic wave shield structure from which the arrangement direction of a clip differs from 2nd embodiment. The top view which shows an example.

  Next, embodiments of the present invention will be described with some examples. In the following description, the description will be made using each of the up / down / left / right and front / rear directions shown in the drawing as needed. However, each of these directions is only a direction defined in order to briefly explain the relative positional relationship between the respective parts constituting the electromagnetic wave shielding structure. That is, when the electromagnetic shielding structure is actually used, the direction in which the electromagnetic shielding structure is directed is arbitrary. For example, the vertical direction shown in the figure is not the vertical direction in relation to gravity. It doesn't matter.

[First embodiment]
First, the first embodiment will be described. The electromagnetic wave shielding structure 1 shown in FIGS. 1A and 1B includes one shield case 3 and four clips 5. The shield case 3 is attached to a position that covers the electronic component 9 mounted on the printed wiring board 7, thereby blocking electromagnetic waves radiated from the electronic component 9 to the outside of the device or electromagnetic waves coming from the outside of the device to the electronic component 9. Metal parts to be used. The clip 5 is a metal part that is fixed on the printed wiring board 7 by soldering and holds the shield case 3 on the printed wiring board 7. The clip 5 is solder-bonded to a conductor pattern having a ground potential on the printed wiring board 7, so that the shield case 3 is grounded on the printed wiring board 7 via the clip 5. It is electrically connected to a conductor pattern that has a potential.

  The clip 5 is formed by punching and bending a metal thin plate. FIGS. 2 (a), 2 (b), 3 (a) to 3 (d). As shown, a base 5A and elastic pieces 5B and 5C are provided.

  The base portion 5A is a portion that is electrically connected to the conductor portion of the printed wiring board by being soldered to the printed wiring board, and the solder joint portions 11A, 11B, 11C and the floating portions 13A, 13B are connected to each other. I have.

  The lower surfaces of the solder joint portions 11A to 11C are joint surfaces with the printed wiring board. The floating portions 13A and 13B are portions that form a gap between the solder joint portions 11A to 11C and the printed wiring board in a state where the solder joint portions 11A to 11C are soldered to the printed wiring board.

  The floating portions 13A and 13B have a width in the front-rear direction that is ½ that of the solder joint portions 11A to 11C, and when viewed in plan (see FIG. 3A), the solder joint portions 11A and 11B. The elastic piece 5B is formed in a range surrounded by three sides by the floating portion 13A, and the elastic piece 5C is formed in a range surrounded by the solder joint portions 11B and 11C and the floating portion 13B.

  The elastic pieces 5B and 5C include base portions 15A, 15B, 15C, and 15D, and folded portions 17A, 17B, 17C, and 17D. The base portions 15A to 15D extend from the floating portions 13A and 13B, and the extending direction is a direction (obliquely downward) approaching the printed wiring board. The folded-back portions 17A to 17D further extend from a location closest to the printed wiring board of the base portions 15A to 15D (location that becomes the lowermost end), and the extending direction is a direction away from the printed wiring board (diagonally upward) ).

  Thereby, the part used as the boundary of the base parts 15A-15D and the folding | returning parts 17A-17D is made into the place closest to a printed wiring board in the elastic pieces 5B and 5C. More specifically, for example, FIG. 4A and FIG. 4B illustrate the root portion 15C and the folded portion 17C, but the portion that becomes the boundary between the root portion 15C and the folded portion 17C is soldered. It is made close to a position where only a slight gap C is formed between the lower surface of the portion 11C (that is, the bonding surface with the printed wiring board). In addition, although illustration is abbreviate | omitted, other base part 15A, 15B, 15D and folding | returning part 17A, 17B, 17D are also. A portion serving as a boundary between them forms a gap C having the same dimension between the lower surface of the solder joint portion 11C (that is, the joint surface with the printed wiring board).

  The interval of the gap C is preferably 1/1000 mm to 50/1000 mm, and more preferably 1/1000 mm to 30/1000 mm. If the distance is about this level, the base portions 15A to 15D do not come into contact with the printed wiring board. Therefore, the effect of wetting up described later can be achieved without affecting the bonding between the solder joint portions 11A to 11C and the printed wiring board. It can be shown to the fullest.

  In the present embodiment, the elastic pieces 5B and 5C are provided on the guide portions 21A and 21B, as shown in FIGS. 2 (a), 2 (b), and 3 (a) to 3 (d). Installation portions 23A and 23B, convex portions, and 25A and 25B are formed.

  The guide portions 21A and 21B are at the upper ends of the folded portions 17A to 17D, and the guide portions 21A and 21B are inclined so as to gradually approach the center in the front-rear direction of the clip 5 from the upper end side to the lower end side of the guide portions 21A and 21B. Is granted.

  The suspended portion 23A is suspended from the lower end of the guide portion 21A at a position between the folded portions 17A and 17B. The suspended portion 23B is suspended from the lower end of the guide portion 21B at a position between the folded portions 17C and 17D. The convex portion 25A is formed on the hanging portion 23A, and the convex portion 25B is formed on the hanging portion 23B.

  Further, a suction surface 29 that can be sucked by a suction nozzle (not shown) of the automatic mounting machine is formed on the upper surface of the solder joint portion 11B. Further, the base 5A and the elastic pieces 5B and 5C are symmetrical with respect to the axis extending in the direction orthogonal to the joint surface (lower surface) of the solder joint 11B, as is apparent from FIGS. 3 (a) and 3 (d). The shaft has a rotationally symmetric shape that has the same shape even if it is rotated halfway around the symmetry axis.

  For this reason, if the suction surface 29 is sucked by the suction nozzle of the automatic mounting machine, the clip 5 can be sucked at a position where the weights of the parts divided on both sides of the symmetry axis coincide with each other. When transferring from the embossing tray (not shown) to the printed wiring board, or when placing the clip 5 on the printed wiring board 7, the clip 5 is difficult to tilt, and the positional accuracy during surface mounting can be improved. it can.

  On the other hand, when the shield case 3 is mounted on the printed wiring board 7 as shown in FIGS. 5A to 5C, the shield case 3 is placed on the surface of the printed wiring board 7 at a position surrounding the electronic component 9. Side wall portions 3A to 3D that are arranged perpendicular to the back surface, and an upper surface portion 3E that closes the upper ends of the side wall portions 3A to 3D are provided.

  Further, in this shield case 3, the outer surfaces of the side walls 3A to 3D are recessed inward at the lower ends of the side walls 3A to 3D (the end on the side of the printed wiring board 7 on the side walls 3A to 3D). Recesses 31A to 31D having a shape that is formed, and recesses 31E to 31H having a shape in which the inner surfaces of the side wall portions 3A to 3D are recessed outward are provided.

  These recesses 31 </ b> A to 31 </ b> H are formed when the shield case 3 is brought into contact with the clip 5 disposed at a predetermined position on the printed wiring board 7 with the lower end of the shield case 3 facing the printed wiring board 7 side. The elastic pieces 5B and 5C are provided at positions where the elastic pieces 5B and 5C can be brought into contact with the inner surfaces of the recesses 31A to 31H.

  More specifically, for example, the pair of recesses 31A and 31E provided on the side wall 3A has a size and a position corresponding to the elastic pieces 5B and 5C included in one clip 5. Similarly, a set of recesses 31B and 31F provided on the side wall 3B, a set of recesses 31C and 31G provided on the side wall 3C, and a set of recesses 31D and 31H provided on the side wall 3D, respectively. Is the size and position corresponding to the elastic pieces 5B and 5C included in one clip 5. Further, the relative positions of the four sets of recesses 31A to 31H are such that when the four clips 5 are arranged on the printed wiring board 7 in association with each set, the arrangement positions of the clips 5 do not overlap each other. At a distance.

  If the recesses 31 </ b> A to 31 </ b> H are provided at such positions, the shield case 3 can be dropped deeper into the printed wiring board 7 side without elastically deforming the elastic pieces 5 </ b> B and 5 </ b> C. The positioning of the clip 5 can be easily performed.

  Explaining with illustration, as shown in FIGS. 6A to 6D, in the case of the shield case 3 having the recesses 31A to 31H (FIGS. 6A to 6D show the side wall portion). 3D and the recess 31D are illustrated), and the elastic pieces 5B and 5C (the elastic piece 5B is illustrated in FIGS. 6A to 6D) are not elastically deformed (see FIG. 6B). Even if it exists, the shield case 3 can be dropped to the position where the gap G1 is formed between the shield case 3 and the printed wiring board 7.

  On the other hand, as shown in FIGS. 6E to 6H, in the case of the shield case 93 without the recesses 31A to 31H (FIGS. 6E to 6H illustrate the side wall portion 93D. In the stage where the elastic pieces 5B and 5C are not elastically deformed (see FIG. 6 (f)), the shield case only reaches a position where the gap G2 (G2> G1) is formed between the shield case 93 and the printed wiring board 7. 93 cannot be dropped.

  Therefore, when the shield cases 3 and 93 are pushed toward the printed wiring board 7 side, the shield case 3 is more likely to be pushed in, and the lateral displacement accompanied by breakage of the elastic pieces 5B and 5C (shift in a direction perpendicular to the pushing direction). ) Is less likely to occur.

  In addition, the shape of the inner surfaces of the recesses 31A to 31H is such that when the shield case 3 is made relatively closer to the printed wiring board 7 from the state in which the elastic pieces 5B and 5C are in contact with the inner surfaces of the recesses 31A to 31H, As shown in FIGS. 6B to 6D, the elastic pieces 5B and 5C are slid along the inner surfaces of the recesses 31A to 31H to gradually increase the deformation amount of the elastic pieces 5B and 5C. However, the elastic pieces 5B and 5C are shaped so as to be able to guide the elastic case 5B and 5C to positions where the shield case 3 can be held.

  That is, the elastic piece 5B in the initial position in the state shown in FIG. 6B is elastically deformed while being guided along the inner surface of the recess 31D when the shield case 3 is pushed toward the printed wiring board 7 side. The position is displaced from a position (a position indicated by a two-dot chain line in FIG. 6C) in a direction indicated by an arrow in FIG. When the shield case 3 is further pushed toward the printed wiring board 7 side, the elastic piece 5B is further elastically deformed while being guided along the inner surface of the recess 31D, and two points in the initial position (FIG. 6D). The position is further displaced from the position indicated by the chain line in the direction indicated by the arrow in FIG. 6D, and the amount of deformation of the elastic piece 5B gradually increases.

  If the recesses 31A to 31H having such shapes are provided, the lower end of the shield case 3 is smoothly pushed into the printed wiring board 7 without being caught by the elastic pieces 5B and 5C. It can be installed smoothly.

  On the other hand, in the case of the shield case 93 without the concave portions 31A to 31H, the lower ends of the side wall portions 93A to 93D abut against the elastic pieces 5B and 5C, as shown in FIGS. Will be. Therefore, compared with the case where the elastic pieces 5B and 5C are slid along the inner surfaces of the recesses 31A to 31H, the feeling of being caught when the shield case 3 is pushed in becomes stronger, and it becomes difficult to push the shield case 93 smoothly.

  In the clip 5, the width of the floating portions 13 </ b> A and 13 </ b> B is narrower than that of the solder joint portions 11 </ b> A to 11 </ b> C (1/2 in this embodiment), so when the shield case 3 is pushed in The narrow floating parts 13A and 13B can be expected to be elastically deformed. In this case, since the elastic pieces 5B and 5C are more elastically deformed with the floating portions 13A and 13B as fulcrums, the shield case 3 can be more strongly fixed to the printed wiring board 7.

  In the present embodiment, since the clip 5 is provided with the hanging portions 23A and 23B, the hanging portions 23A and 23B are also elastically deformed, and the shield case 3 is pressed by the elastic force. As a result, the pressing force from the convex portions 25 </ b> A and 25 </ b> B acts on the shield case 3, whereby the shield case 3 is fixed to the printed wiring board 7.

  By the way, in the soldering process of the clip 5, a solder paste is applied on the printed wiring board 7, the clip 5 is placed thereon, and soldering is performed through heating in a reflow furnace. At that time, for example, if the amount of the applied solder paste is large, excess solder melted in the furnace may flow out from the interface between the solder joints 11 </ b> A to 11 </ b> C and the printed wiring board 7.

  In such a case, in the case of the clip 5 of this embodiment, when the solder that has flowed out reaches the lowermost ends of the elastic pieces 5B and 5C, the solder is both on the base portions 15A to 15D side and the folded portions 17A to 17D side. Divided into wet. Therefore, compared with the case where there is no portion corresponding to the base portions 15A to 15D, the amount of solder that wets to the folded portions 17A to 17D is reduced, and the solder formed on the folded portions 17A to 17D by the wet solder. Since the size of the fillet can be made smaller, it is possible to suppress the rigidity of the folded portions 17A to 17D from being excessively increased with the formation of the solder fillet, and to suppress the spring property of the folded portions 17A to 17D from being lowered. can do.

  That is, if an elastic piece having only a structure corresponding to the folded portions 17A to 17D is to be provided, a configuration similar to the technique described in Patent Document 1 is employed without providing the floating portions 13A and 13b, and soldering is performed. A flat base portion may be provided at a position corresponding to the joint portions 11A to 11C, and an elastic piece having only a structure corresponding to the folded portions 17A to 17D may be extended from the base portion. However, with such a structure, since the portion corresponding to the base portions 15A to 15D does not exist, all of the excess solder wets up to the portion corresponding to the folded portions 17A to 17D. Since the size of the solder fillet formed in the portion corresponding to the folded portions 17A to 17D by the solder becomes large, the rigidity of the folded portions 17A to 17D is easily increased along with the formation of the solder fillet, and the folded portions 17A to 17D. Appropriate portions tend to be less springy.

  On the other hand, if it is only desired to prevent the solder from getting wet to the portions corresponding to the folded portions 17A to 17D, a configuration similar to the technique described in Patent Document 2 is adopted, and a structure corresponding to the floating portions 13A and 13B is employed. In addition, it is possible to extend an elastic piece having only a structure corresponding to the folded portions 17A to 17D from the portions corresponding to the floating portions 13A and 13B. However, with such a structure, there is a problem that the dimension in the height direction of the clip becomes larger than when the structure corresponding to the folded portions 17A to 17D extends from the height position corresponding to the solder joint portions 11A to 11C. Further, excessive solder may flow to the electronic component 9 side if it cannot wet up to the portions corresponding to the elastic pieces 5B and 5C.

  In this respect, in the clip 5 of the present embodiment, the portion where the folded portions 17A to 17D extend is the lower end side of the base portions 15A to 15D, and the height position thereof is equivalent to the solder joint portions 11A to 11C. It is possible to reduce the height sufficiently. In addition, as described above, unlike the case where the structure corresponding to the turn-back portions 17A to 17D is directly extended from the portion corresponding to the solder joint portions 11A to 11C, the excess solder wets toward the base portions 15A to 15D. In addition, it is possible to reduce the amount of solder that gets wet to the folded portions 17A to 17D, and it is possible to suppress the solder from flowing to the electronic component 9 side.

  Further, as the size of the clip 5 becomes smaller, it becomes more difficult to ensure the elasticity of the elastic pieces 5B and 5C. However, if the base portions 15A to 15D are provided, the spring length of the elastic pieces 5B and 5C as a whole is gained. It is possible to improve the spring properties of the elastic pieces 5B and 5C.

[Second Embodiment]
Next, a second embodiment will be described. In addition, since the clip and shield case which comprise the electromagnetic wave shield structure illustrated as 2nd embodiment are provided with the part which has a function equivalent to the clip and shield case illustrated in 1st embodiment, 1st embodiment and Parts having equivalent functions are denoted by the same reference numerals as in the first embodiment, and detailed description thereof is simplified or omitted, and differences from the first embodiment will be mainly described.

  As shown in FIGS. 7A and 7B, the electromagnetic wave shielding structure 41 exemplified as the second embodiment includes one shield case 43 and four clips 45. As shown in FIGS. 8A to 8D, the clip 45 is obtained by changing the two elastic pieces 5B and 5C in the first embodiment to a single elastic piece 5B. . With this change, the left-right dimension is shorter than that of the first embodiment, and the size and weight are reduced as compared to the first embodiment.

  More specifically, the base portion 5A includes solder joint portions 11A and 11B and a floating portion 13A, and the elastic piece 5B includes base portions 15A and 15B and folded portions 17A and 17B. The base portions 15A and 15B extend from the floating portion 13A, and the extending direction is a direction (obliquely below) approaching the printed wiring board. The folded portions 17A and 17B further extend from a place closest to the printed wiring board of the base parts 15A and 15B (a place that becomes the lowermost end), and the extending direction is a direction away from the printed wiring board (diagonally upward). ). Thereby, the location that becomes the boundary between the base portions 15A and 15B and the folded portions 17A and 17B is the location closest to the printed wiring board in the elastic piece 5B.

  Therefore, as in the first embodiment, when the melted solder comes into contact with the elastic piece 5B, the solder is divided into both the base portions 15A and 15B and the folded portions 17A and 17B, and is turned up. The amount of solder that gets wet to the portions 17A and 17B is reduced. As a result, since the size of the solder fillet formed on the folded portions 17A and 17B can be reduced, it is possible to suppress the rigidity of the folded portions 17A and 17B from being excessively increased, and the spring properties of the folded portions 17A and 17B are reduced. Can be suppressed.

  The shield case 43 has recesses 31 </ b> A to 31 </ b> D corresponding to the shape of the clip 45. However, since the shape of the clip 45 is different from that of the first embodiment, portions corresponding to the recesses 31E to 31H are not provided.

  Even in the electromagnetic wave shielding structure 41 as described above, the recesses 31A to 31D are formed in the shield case 43. Therefore, when the shield case 43 is attached, the elastic pieces are formed along the inner surfaces of these recesses 31A to 31D. 5B can be elastically deformed while being guided, whereby the shield case 43 can be smoothly pushed between the four clips 45.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to said specific embodiment, In addition, it can implement with a various form.

  For example, in each case shown in the first and second embodiments, each of the four sides of the shield case 3, 43 that looks square in plan view is held by the clips 5, 45. In this case, if the shield cases 3 and 43 are held in at least two places, the shield cases 3 and 43 can be fixed to the printed wiring board 7, so whether or not the shield cases 3 and 43 are held in four places. Is optional.

  That is, for example, when holding a smaller shield case, the shield case may be held at less than four locations, and when holding a larger shield case, multiple locations exceeding four locations may be used. You can also hold the shield case.

  If a more specific example is also shown, for example, one shield case 53 may be held by two clips 55 like the electromagnetic wave shield structure 51 shown in FIGS. 9A and 9B. . Even in this case, the shield case 53 can be smoothly attached by providing the concave portions 57A to 57D having the same shape as the concave portions 31A to 31H as described above.

  Moreover, in the example shown in the said embodiment, recessed part 31A-31D (henceforth an outer surface side recessed part) made into the shape which dented the outer surface of side wall part 3A-3D inside, and side wall part 3A-. The recesses 31E to 31H (hereinafter referred to as inner surface side recesses) having a shape in which the 3D inner surface is recessed outward are provided, but either the outer surface side recess or the inner surface side recess is either one. You may just provide.

  For example, in the case of the electromagnetic wave shield structure 51 shown in FIGS. 9A and 9B, the recesses 57A and 57B are both outer surface side recesses, and in this case, the inner surface side recesses are not provided. Even with such a structure, the shield case 53 can be smoothly attached as compared with a structure in which no recess is provided. Accordingly, the degree to which the concave portion is provided may be set as appropriate in consideration of the balance between the labor of processing and the smoothness of attachment, and it is not necessary to provide the concave portion in association with all the elastic pieces.

  Moreover, in the case of the said embodiment, since the two elastic pieces 5B and 5C are provided in the one clip 5, the shield case is hold | maintained only with the one clip 5 on account of having such a structure. Although it is difficult, three or more portions corresponding to the elastic pieces 5B and 5C may be provided in one clip. In this case, the shield case can be held by only one clip. Even when such a clip is employed, the shield case can be smoothly attached by providing the concave portions having the same shape as the concave portions 31A to 31H as described above.

  Furthermore, as described above, the clip 5 illustrated in the above embodiment is difficult to hold the shield case 3 with only one clip 5, but in addition to one clip 5, another holding structure or another clip is used. If used together, it is possible to hold the shield case 3, and therefore it is not essential to use a plurality of clips 5 when using the clips 5.

  In addition, in the clip 5 illustrated in the above embodiment, the base portions 15A, 15B, 15C, and 15D included in the elastic pieces 5B and 5C approach the printed wiring board 7 in the extending direction from the floating portions 13A and 13B. Although the direction (diagonally downward) is set, the base portions 65A, 65B, 65C, and 65D are located on the sides of the floating portions 63A and 63B (that is, the printed wiring board) as in the clip 61 shown in FIG. In a direction substantially parallel to the front and back surfaces. In this case, since the base portions 65A, 65B, 65C, and 65D are separated from the printed wiring board 7 side as compared with the above-described embodiment, it is difficult for the solder to contact the base portions 65A, 65B, 65C, and 65D.

  Further, in the clip 5 illustrated in the above embodiment, the base portion 5A is provided with the floating portions 13A and 13B. However, like the clip 71 shown in FIG. 10B, the base portion 71A has the floating portion 13A. , 13B may not be provided (that is, a flat base 71A).

  Furthermore, in the second embodiment, the elastic piece 5B is arranged on the outer peripheral side of the shield case 43 for all the four clips 45. However, like the electromagnetic wave shield structure 81 shown in FIG. In arranging the same clip 45 as in the second embodiment, the elastic piece 5B may be arranged on the inner peripheral side of the shield case 82. Alternatively, as in the electromagnetic wave shield structure 83 shown in FIG. 11B, the elastic piece 5B is the outer peripheral side of the shield case 84 for some clips 45, and the elastic piece 5B is a shield case for the remaining some clips 45. 84 may be arranged on the inner peripheral side.

  In any of these cases, when the shield cases 82 and 84 are attached, the elastic pieces 5B are elastically deformed and pressed against the shield cases 82 and 84, whereby the plurality of clips 45 cooperate to shield the shield case 82. , 84 are held. In these electromagnetic wave shield structures 81 and 83, the floating portion 13A is elastically deformed and twisted to improve the pressure contact force of the elastic piece 5B, and the hanging portion 23A is elastically deformed and its elastic The point etc. which press the shield cases 82 and 84 with force are the same as that of 1st, 2nd embodiment.

  1, 41, 51, 81, 83 ... electromagnetic shielding structure, 3, 43, 53, 82, 84 ... shield case, 3A, 3B, 3C, 3D ... side wall, 3E ... top surface 5, 45, 55, 61, 71 ... clip, 5A, 71A ... base, 5B, 5C ... elastic piece, 7 ... printed wiring board, 9 ... electronic component, 11A, 11B , 11C: Solder joints, 13A, 13B, 63A, 63B ... Floating parts, 15A, 15B, 15C, 15D, 65A, 65B, 65C, 65D ... Base parts, 17A, 17B, 17C, 17D ... folded portion, 17A ... directly folded portion, 21A, 21B ... guide portion, 23A, 23B ... hanging portion, 25A, 25B ... convex portion, 29 ... suction surface, 31A, 31B, 31C, 31D, 31E 31F, 31G, 31H, 57A, 57B ··· recess.

Claims (4)

A shield case that blocks electromagnetic waves radiated from the electronic components or electromagnetic waves arriving at the electronic components by being attached to a position that covers the electronic components mounted on the printed wiring board;
The shield case is held on the printed wiring board by being fixed on the printed wiring board by soldering and being pressed against the shield case with an elastic piece that is elastically deformed in contact with the shield case. With at least one clip and
The shield case, when attached on the printed wiring board, has a side wall portion that is arranged perpendicularly to the front and back surfaces of the printed wiring board at a position surrounding the periphery of the electronic component, On the side wall portion, on the side of the printed wiring board side, a concave portion having a shape in which the outer surface of the side wall portion is recessed inward, and an inner surface of the side wall portion is recessed outward. Of the recesses that are shaped, at least one recess is provided,
When the shield case is brought into contact with the clip disposed at a predetermined position on the printed wiring board in a state where the end portion of the shield case faces the printed wiring board side, It is provided at a position where the elastic piece can be brought into contact with the inner surface of the recess,
In addition, the shape of the inner surface of the recess is such that when the shield case is moved relatively closer to the printed wiring board from the state where the elastic piece is in contact with the inner surface of the recess, the elastic piece is moved into the recess. By sliding along the inner surface, the elastic piece can be guided to a position where the elastic case can hold the shield case while gradually increasing the deformation amount of the elastic piece. An electromagnetic shielding structure characterized by having One of the clips has a single elastic piece;
The shield case is held by the elastic piece included in each of the plurality of clips cooperating, or the elastic piece included in the clip cooperating with another member. The electromagnetic shielding structure as described. One clip has a plurality of the elastic pieces,
The elastic piece provided in each of the plurality of clips cooperates, the elastic piece provided in the clip cooperates with another member, or the plurality of elastic pieces provided in one clip cooperate. The electromagnetic shielding structure according to claim 1, wherein the shield case is held by. The clip has, as the elastic piece, a first elastic piece that is pressed against the outer surface of the side wall portion, and a second elastic piece that is pressed against the inner surface of the side wall portion,
The first elastic piece and the second elastic piece are formed at positions that do not overlap each other when viewed from the direction orthogonal to the inner surface and the outer surface of the side wall portion,
In the shield case, a position corresponding to the first elastic piece is formed with a first recess having a shape in which the outer surface of the side wall is recessed inward, and the position corresponds to the second elastic piece. The electromagnetic wave shielding structure according to claim 3, wherein a second concave portion having a shape in which an inner surface of the side wall portion is recessed outward is formed.