JP2009064911A - Electronic circuit module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic circuit module capable of highly accurately specifying the mounting position of a cover body to a circuit board. <P>SOLUTION: In this electronic circuit module equipped with a circuit board 10 in which cut parts 12 along curved surfaces 12a are provided at four corner parts respectively and a box-shaped cover body 11 made of a metal plate including four mounting legs 16 individually disposed in these cut parts 12 and mounted to the circuit board 10 through the mounting legs 16 so as to cover the top face of the circuit board 10, bent pieces 17 obliquely bent (preferably by almost 45 degrees) toward the inside of the cover body 11 are formed in the four mounting legs 16 respectively, one side fringe 17a on the tip side of each bent piece 17 is made to come close to the curved surface 12a of the corresponding cut part 12, and these four bent pieces 17 are almost radially dispersedly disposed when viewing from the center part of the circuit board 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic circuit module configured by attaching a cover body made of a metal plate to a circuit board, and in particular, has a structure in which mounting legs of the cover body are arranged in notches provided at four corners of the circuit board. The present invention relates to an electronic circuit module.

  For example, in a wireless communication device or the like, an electronic circuit module configured by attaching a cover body such as a shield case made of a metal plate to a circuit board on which a high-frequency circuit or the like is disposed may be used. In general, in such an electronic circuit module, a cover body formed in a box shape is attached so as to cover the upper surface of the circuit board. Particularly in the case of a small electronic circuit module, the cover body is provided at the four corners of the circuit board. There is a known structure in which the mounting legs of the cover body are arranged in the notches, and each mounting leg is soldered to the corresponding notch or the electrode or land exposed in the vicinity thereof (for example, Patent Document 1).

FIG. 6 is a bottom view showing a conventional example of this type of electronic circuit module, in which a box-shaped cover body 2 made of a metal plate is attached to a substantially rectangular circuit board 1. In the figure, at four corners of the circuit board 1 are provided cutout portions 3 cut out along the curved surface. These notches 3 are formed at the intersection of vertical and horizontal dividing lines on the large substrate at the stage of a large substrate (not shown) for removing a large number of circuit boards 1. When the circuit board 1 is a resin substrate such as a phenol resin, each slot is formed with high accuracy by a drill such as a router. The cover body 2 includes a rectangular top plate portion 7, a pair of opposing side wall portions 4 bent at a right angle at the long side of the top plate portion 7, and a relative shape bent at a right angle at the short side of the top plate portion 7. The pair of side wall portions 5 facing each other and a total of four mounting legs 6 projecting downward from both longitudinal ends of each side wall portion 4, and each mounting leg 6 corresponds to each notch portion 3 of the circuit board 1. It is arranged at the position to do. When attaching the cover body 2 to the circuit board 1, the attachment legs 6 are inserted into the corresponding cutouts 3 from above the circuit board 1, and the side walls 4, 5 are connected to the circuit board 1. Contact the top surface. By doing so, the height position of the cover body 2 with respect to the circuit board 1 can be accurately defined, and the position of the mounting leg 6 is regulated by the surface of the corresponding notch 3. The positional deviation of the cover body 2 can be suppressed. After the cover body 2 is thus attached to the circuit board 1 in a positioned state, each cover leg 2 is electrically and mechanically soldered by soldering each mounting leg 6 to an electrode (not shown) on the surface of the notch 3. The electronic circuit module is completed by being connected to the circuit board 1.
JP 2005-64157 A

  However, in the conventional electronic circuit module shown in FIG. 6, the mounting legs 6 of the cover body 2 are easy to position in the plate thickness direction but cannot be accurately positioned in the width direction in the notch 3 of the circuit board 1. There was a bug. That is, as shown in the partially enlarged view of FIG. 7, since the mounting leg 6 is disposed along the flat surface 3a of the notch 3, the allowable value of the clearance C1 between the flat surface 3a and the mounting leg 6 is reduced. Although the positional deviation in the Y direction can be suppressed by setting, if the clearance C1 changes within the allowable range, the clearance C2 between the curved surface 3b of the notch 3 and the mounting leg 6 changes greatly. For this reason, the cover body 2 must be set with a large allowable value of the clearance C2. Therefore, the cover body 2 is likely to be displaced in the X direction in FIG. 7, and thus it is difficult to define the mounting position with respect to the circuit board 1 with high accuracy.

  In addition, a round hole is formed in the large-sized substrate instead of a long hole, and a cutout part obtained by dividing the round hole into four equal parts may be formed at four corners of the circuit board. In this case, the surface of the cutout part Therefore, it becomes more difficult to accurately define the mounting position of the cover body in the in-plane direction of the circuit board.

  The present invention has been made in view of the actual situation of the prior art, and an object of the present invention is to provide an electronic circuit module capable of defining the mounting position of the cover body with respect to the circuit board with high accuracy.

  In order to achieve the above object, the electronic circuit module of the present invention is individually arranged in a circuit board in which cut portions along curved surfaces are provided at four corners, and in each cut portion. A box-shaped cover body made of a metal plate attached to the circuit board through the mounting leg so as to cover the upper surface of the circuit board, and each of the mounting legs has the cover. Forming bent pieces obliquely inward of the body, bringing one side edge of the bent pieces close to the curved surface of the corresponding notch, and the bent pieces The circuit board is arranged so as to be distributed substantially radially as viewed from the center of the circuit board.

  In the electronic circuit module configured as described above, the four attachment legs of the cover body arranged in the notches at the four corners of the circuit board are each bent inward so as to be close to the curved surface of the corresponding notch. Since these four bent pieces are distributed in a substantially radial manner when viewed from the central portion of the circuit board, the cut pieces corresponding to one side edge on the tip side of each bent piece are formed. It is not necessary to expect a large clearance between the curved surface of the notch portion, and the displacement of the cover body in the in-plane direction of the circuit board can be effectively suppressed.

  In the above configuration, when the bent piece is formed by bending one side portion of the mounting leg of the cover body inwardly by approximately 45 degrees, the bent piece in the notch portion present at both ends of each side of the circuit board. The tip of each folded piece can be positioned in a plane that is substantially orthogonal and the folded pieces in the notch at diagonal positions can be located in a substantially parallel (or the same) plane. Therefore, the dimension setting can be performed in such a manner that the one side edge of the side and the curved surface of the corresponding cutout portion are very close to each other, and the attachment position of the cover body with respect to the circuit board can be defined with extremely high accuracy.

  In the above configuration, if the circuit board is a resin substrate and the notch is formed by a drill, the notch can be formed with high accuracy. It becomes easy to improve accuracy.

  According to the electronic circuit module of the present invention, the four attachment legs of the cover body arranged in the notches at the four corners of the circuit board are each bent inward so as to be close to the curved surface of the corresponding notch. Since the bent pieces are formed and these four bent pieces are distributed in a substantially radial manner when viewed from the center of the circuit board, notches corresponding to one side edge of each bent piece are provided. It is no longer necessary to allow for a large clearance between the curved surface of the part and the positional displacement of the cover body in the in-plane direction of the circuit board can be effectively suppressed. Therefore, the attachment position of the cover body with respect to the circuit board can be defined with high accuracy.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an electronic circuit module according to an embodiment of the present invention, FIG. 2 is a bottom view of the electronic circuit module, and FIGS. 2 is an enlarged view of a main part of FIG. 5 and FIG.

  The electronic circuit module shown in FIG. 1 and FIG. 2 is configured by attaching a box-shaped cover body 11 made of a metal plate to a substantially rectangular circuit board 10 which is a resin substrate such as phenol resin. The upper surface of the circuit board 10 is substantially covered. At the four corners of the circuit board 10, there are provided cutout portions 12 cut out along curved surfaces 12a (see FIGS. 3 and 4). These notches 12 are formed at the intersection of vertical and horizontal dividing lines on the large substrate at the stage of a large substrate (not shown) for removing a large number of circuit boards 10. Each slot is formed with high accuracy by a drill such as a router. Although not shown, various electronic components are mounted on the circuit board 10 to form a desired electric circuit.

  The cover body 11 includes a rectangular top plate portion 13, a pair of opposing side wall portions 14 bent at a right angle at the long side of the top plate portion 13, and a relative shape bent at a right angle at the short side of the top plate portion 13. The pair of side wall portions 15 facing each other, and a total of four pieces of mounting legs 16 projecting downward from both ends in the longitudinal direction of each side wall portion 14, approximately 45 degrees inward on one side portion of each mounting leg 16. A bent piece 17 (see FIG. 5) is formed. The four mounting legs 16 having the bent pieces 17 are disposed at positions corresponding to the notches 12 of the circuit board 10, and one side edge 17 a (see FIG. 3-5) is set so as to face the curved surface 12a of the corresponding notch 12 in close proximity.

  When the cover body 11 is attached to the circuit board 10, the attachment legs 16 are inserted into the corresponding notches 12 from above the circuit board 10, and the side wall parts 14, 15 are connected to the circuit board 10. Contact the top surface. By doing so, the height position of the cover body 11 with respect to the circuit board 10 can be accurately defined, and the bent pieces 17 of the mounting legs 16 are positioned in the corresponding cutout portions 12. The attachment position of the cover body 11 in the in-plane direction can be defined with high accuracy. After the cover body 11 is thus attached to the circuit board 10 in a positioned state, each cover leg 11 is electrically and mechanically soldered by soldering each mounting leg 16 to an electrode (not shown) on the surface of the notch 12. The electronic circuit module is completed by being connected to the circuit board 10.

  Next, the reason why the mounting leg 16 of the cover body 11 can be accurately positioned in the notch 12 of the circuit board 10 will be described in detail. As shown in FIG. 2, the bent pieces 17 of the mounting legs 16 are bent approximately 45 degrees inward of the cover body 11, so that the four bent pieces 17 are substantially omitted when viewed from the center of the circuit board 10. They are distributed radially. Here, the bent pieces 17 in the notch 12 that exist at both ends of each side of the circuit board 10 are located in a plane that is substantially orthogonal and is folded in the notch 12 that is at a diagonal position. The curved pieces 17 are located in a substantially parallel plane. Therefore, with respect to the upper left and lower right bent pieces 17 in FIG. 2, the allowable value of the clearance C3 (see FIG. 3) between the corresponding notched portions 12 and the curved surface 12a is set small. A positional shift in the X1 direction can be suppressed. Further, with respect to the upper right and lower left bent pieces 17 in FIG. 2, the tolerance C4 (see FIG. 4) between the corresponding notched portions 12 and the curved surface 12a is set to be small by setting Y1. The positional deviation in the direction can be suppressed. Even if the clearance C3 changes within the allowable range, the clearance C4 does not change greatly. Similarly, even if the clearance C4 changes within the allowable range, the clearance C3 does not change greatly. It is easy to set both the allowable values of C3 and C4 small. As a result, the attachment position of the cover body 11 in the in-plane direction of the circuit board 10 can be defined with high accuracy.

  As described above, the electronic circuit module according to this embodiment is provided with the notch portions 12 respectively corresponding to the four attachment legs 16 of the cover body 11 disposed in the notch portions 12 at the four corners of the circuit board 10. The bent pieces 17 are formed inwardly bent so as to be close to the curved surface 12a, and these four bent pieces 17 are distributed substantially radially as viewed from the center of the circuit board 10. It is no longer necessary to allow a large clearance between the one side edge 17a of each bent piece 17 and the corresponding curved surface 12a of the notch 12, and the position of the cover body 11 in the in-plane direction of the circuit board 10 is eliminated. Deviation can be effectively suppressed. In particular, in the present embodiment example, since the bent piece 17 is formed by bending one side portion of each mounting leg 16 inward by approximately 45 degrees, the one side edge 17a on the distal end side of each bent piece 17 is formed. Thus, the dimension can be set such that the corresponding curved surface 12a of the notch 12 is very close. Therefore, the attachment position of the cover body 11 with respect to the circuit board 10 can be defined with extremely high accuracy.

  In addition, although the case where the circuit board 10 which consists of a resin substrate was used was demonstrated in the said embodiment example, even if the circuit board 10 is a ceramic substrate, this invention is applicable.

1 is an external view of an electronic circuit module according to an embodiment of the present invention. It is a bottom view of the electronic circuit module shown in FIG. FIG. 3 is an enlarged view of a main part of FIG. 2. FIG. 3 is an enlarged view of a main part of FIG. 2. It is a principal part perspective view which shows the attachment leg of the cover body shown to FIG. It is a bottom view of the electronic circuit module which concerns on a prior art example. It is the elements on larger scale of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Circuit board 11 Cover body 12 Notch part 12a Curved surface 16 Mounting leg 17 Bending piece 17a One side edge C3, C4 Clearance

Claims (3)

A circuit board having notches along the curved surface at four corners, and four mounting legs individually disposed in each notch, so as to cover the upper surface of the circuit board And a box-shaped cover body made of a metal plate attached to the circuit board via the mounting legs,
Each of the mounting legs is formed with a bent piece that is bent obliquely toward the inside of the cover body, and one side edge of the bent piece is adjacent to the curved surface of the corresponding notch. The electronic circuit module is characterized in that the bent pieces are arranged so as to be distributed substantially radially as viewed from the center of the circuit board.   2. The electronic circuit module according to claim 1, wherein the bent piece is formed by bending one side portion of the mounting leg inward approximately 45 degrees.   3. The electronic circuit module according to claim 1, wherein the circuit board is a resin substrate, and each of the notches is formed by a drill.

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