JP3577256B2 - Electronic component and method of assembling electronic component - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic component in which a circuit board is housed in a metal case and arranged vertically, and is suitable for an electronic component that requires a shield such as a DC / DC converter.
[0002]
[Prior art]
Conventionally, as an electronic component having a structure in which a circuit board is housed in a metal case in a vertical state and covered by the metal case, a rectangular top plate and four side walls described in JP-A-11-220284 are known. Are known.
Further, in this publication, a retaining claw is formed at the end of a side wall constituting a metal case, and after the circuit board and a mold case supporting the circuit board are inserted, the retaining claw is bent to be bent. By locking the board, the circuit board and the mold case were prevented from falling out of the metal case.
[0003]
[Problems to be solved by the invention]
However, in the developed shape shown in FIG. 9 before the bending of the metal case, the ratio of wasted material was large and the material cost was high. Furthermore, in order to prevent the mold case and the circuit board from falling out of the metal case, it is necessary to form the retaining claw after the assembly of these components, which increases the number of processing steps and the processing cost. I was
The present invention has been made in view of the above circumstances, and has as its object to provide an electronic component and an electronic component assembling method that can reduce a manufacturing cost for processing and manufacturing a metal case.
[0004]
[Means for Solving the Problems]
The electronic component according to claim 1, wherein the circuit board is housed and shielded in a metal case formed of a single metal plate,
A top plate formed in a rectangular shape having a pair of lateral sides facing each other and a pair of vertical sides extending in a direction intersecting these lateral sides,
Two side walls formed by being bent at a pair of lateral sides and extending along substantially the same direction as each other;
Two pieces which are each bent at the side of the side wall extending crossing the horizontal side and extend along the vertical side and opposite to each other,
The one metal plate is provided,
A concave portion is provided on the circuit board, and a convex portion engaging with the concave portion is provided on at least one of the two pieces,
A step is formed on at least one of these two pieces, and the two pieces overlap each other on the tip side of the piece from the step,
A first projection is formed on one of the two pieces, and a second projection sandwiching the circuit board with the first projection is formed on the other piece .
[0005]
According to the electronic component according to the first aspect, the top plate is formed in a rectangular shape having a pair of lateral sides facing each other and a pair of vertical sides extending in a direction intersecting the lateral sides. Is done. Two side walls are formed by being bent at a pair of lateral sides of the top plate and extending substantially in the same direction. Further, two pieces are provided so as to be bent with respect to the side wall at the side of the side wall extending crossing the horizontal side and to extend along the vertical side and to face each other.
[0006]
Then, one metal plate of these top plate, provided with two side walls and two support sections, the distal end side of the two support sections are that overlap each other, the metal case is formed by one metal plate, the metal The circuit board is housed in the case to form a shielded electronic component.
[0007]
As described above, by protruding a piece for forming another side wall disposed to intersect with these side walls from a pair of side walls connected to the top plate, material can be more efficiently removed than the metal case according to the related art. As a result, the material removal is optimized, and the material yield is improved. As a result, the amount of material to be discarded when manufacturing the metal case is reduced, so that not only the material cost can be reduced, but also the environment is excellent.
Furthermore, by making the punching shape efficient so that the material yield is improved, the die cost can be reduced as the small punching die becomes a small punching shape that can be pressed, and the total manufacturing cost can be reduced. Cost reduction can be achieved.
[0011]
On the other hand, according to the present invention, since the convex portion engaging with the concave portion provided on the circuit board is provided on any one of the portions, the opening of the metal case is slightly formed by utilizing the elastic deformation of the metal. The circuit board is inserted with a force applied to open it, and then the force is released to eliminate the extra opening of the opening, and the concave portion of the circuit board and the convex portion of one portion are engaged. In addition, it is possible to prevent the circuit board from falling out of the metal case.
Therefore, it is not necessary to bend the retaining claw protruding from the metal case as in the related art, and the manufacturing cost is reduced.
[0012]
On the other hand, in this aspect, mutual stepped portion at least in one of the two support sections which Ru extending to face are formed in the two support sections at the distal end side of the support sections than the step portion is to overlap each other , to one of the two support sections together with the first projecting portion is formed, the second projecting portion sandwiching the circuit board between the first projecting portion is formed in the other of the support sections.
[0013]
Therefore , since the position of the circuit board is regulated by being sandwiched between the first projecting portion and the second projecting portion, processing for fixing the circuit board after insertion of the circuit board into the metal case can be performed, As the need to insert the mold case supporting the circuit board into the metal case as described above is eliminated, the manufacturing cost for manufacturing the mold case is also reduced.
[0014]
According to a second aspect of the present invention, there is provided a method for assembling an electronic component, comprising: a metal case having two side walls connected to a top plate and two pieces each extending from the side walls, and one end of which is an opening;
Thereafter, a force is applied to the metal case to deform the metal case within the range of elastic deformation so that the opening side of the metal case is expanded, and in this state, the circuit board in which the concave portion is formed in advance is opened. From the side into the metal case,
Next, by releasing the force applied to the metal case, the convex portion provided in advance on one piece is engaged with the concave portion of the circuit board.
[0015]
According to the invention of assembling method of an electronic component according to claim 2, elastic two side walls and the metal case by applying a force to the metal case having a 2 by one of the support sections extending respectively from side walls connected with the top plate The circuit board in which the concave portion is formed in advance is inserted into the metal case in a state in which the metal plate is deformed to slightly widen the opening side of the two metal portions. Thereafter, the force applied to the metal case is released, and the projection provided on one side, for example, near the opening of the metal case is engaged with the recess of the circuit board.
[0016]
Therefore, by protruding from the two side walls connected to the top plate, one part for forming another side wall arranged to intersect with these side walls, and by making the tip sides of the one part overlap each other, Material removal is more efficient than the metal case according to the prior art, and the material removal is optimized, and the material yield is improved.
As a result, as in the case of the first aspect, the amount of material to be discarded is reduced, so that the material cost and the die cost can be reduced, so that not only can the total manufacturing cost be reduced, but also the environment is excellent. .
[0017]
Further, the circuit board is inserted by slightly opening the opening of the metal case using the elastic deformation of the metal, and then the force is released and the opening amount of the opening is reduced by a simple operation. The concave portion provided and the convex portion provided on one piece are engaged with each other, thereby preventing the circuit board from falling out of the metal case. Therefore, similarly to the first aspect, it is not necessary to bend the retaining claw, and the manufacturing cost is reduced.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be clarified by describing embodiments of an electronic component according to the present invention with reference to the drawings.
FIGS. 1 and 2 show a metal case 12 which is an outer frame of an electronic component 10 which is a DC / DC converter according to an embodiment of the present invention. As shown in FIGS. 1 and 2, the metal case 12 formed of a steel plate having a thickness of 0.4 mm includes a rectangular top plate 14 having a pair of horizontal sides 14A and a pair of vertical sides 14B. Is provided. Then, two side walls 16 and 18 are formed so as to be bent at a pair of lateral sides 14A constituting the top plate 14 and extend along substantially the same direction.
[0019]
One of the two side walls 16, 18 is bent at the side 16 A along the case height direction (Z direction in FIG. 2) on both sides of the side wall 16, and the side wall facing the side wall 16. Each piece 22 is bent at a side 18A on both sides of the same 18 and also along the case height direction, and these two pieces 20 and 22 extend along a pair of vertical sides 14B of the top plate 14 and mutually. Each is provided so as to extend in opposition.
[0020]
Further, as shown in FIG. 3, the sum of the length W1 of the piece 20 and the length W2 of the piece 22 is made longer than the depth dimension W which is the length of the vertical side 14B of the top plate 14, and The tip ends of the two pieces 20 and 22 overlap each other. Further, a step portion 20C for slightly shifting the tip side toward the inside of the metal case 12 is formed on the piece portion 20 so as to extend in the case height direction. Due to the presence of the step portion 20C, these piece portions 20, 22 overlap each other without any problem.
[0021]
On the other hand, a circuit board 30 having substantially the same width dimension as the length of the lateral side 14A of the top plate 14 is accommodated in the metal case 12, and the lower end of the circuit board 30 has recesses 30A at both ends. Are provided respectively. On the other hand, a protrusion 20B for engaging with the recess 30A of the circuit board 30 is provided on the portion 20 near the opening 12A of the metal case 12 in the Y direction in FIGS. It is provided to protrude.
[0022]
Further, a first protruding portion 20 </ b> A is provided on the inner side of the metal case 12 of the piece portion 20 so as to protrude in the Y direction in FIGS. 3 and 4, and is bent with respect to the side wall 18. The formed one portion 22 is formed with three second protruding portions 22A along the case height direction. The second protruding portions 22A are provided so as to protrude toward the X direction in FIG. 4, respectively, and slits are formed on both sides of the second protruding portion 22A to facilitate protruding.
[0023]
The gap between the first protrusion 20A and the second protrusion 22A is the same as or slightly smaller than the thickness of the circuit board 30 without the circuit board 30. The gap between the protrusion 20B and the second protrusion 22A is smaller than the thickness of the circuit board 30.
As described above, the position of the circuit board 30 is regulated by sandwiching the circuit board 30 between the first projecting portion 20A and the second projecting portion 22A, and the projecting portion 20B is engaged with the concave portion 30A. The escape from inside the metal case 12 is prevented.
[0024]
Further, leg portions 24 are formed below the two side walls 16 and 18 so as to project one by one, and connection terminals 32 project from the circuit board 30. Therefore, as shown in FIG. 1, the legs 24 of the metal case 12 and the terminals 32 of the circuit board 30 are inserted into the holes of the printed circuit board 34, respectively, and the legs 24 and the terminals 32 are crimped or soldered. , And is electrically connected to the printed circuit board 34. At this time, the legs 24 are connected to the ground pattern of the printed circuit board 34 to shield the circuit on the circuit board 30.
[0025]
Next, assembly of the electronic component 10 according to the present embodiment will be described.
A circuit for a DC / DC converter is previously arranged on a substrate having a concave portion 30A at an end to form a circuit substrate 30 shown in FIG. Further, by punching a plate-shaped metal material by pressing and forming a single metal plate 40 shown in FIG. 7 which is punched out, as shown in FIG. 2 and FIG. A hexahedral metal case 12 having two side walls 16, 18 and two pieces 20, 22 extending from side sides 16 A, 18 A on both sides of the side walls 16, 18, respectively, and having one end as an opening 12 A is provided. It is formed. In this press working, the first projection 20A, the projection 20B, the step 20C, the second projection 22A, the leg 24 and the like are formed.
[0026]
On the other hand, aside from the press working of the metal case 12, a jig 42 shown in FIGS. 5 and 6 for inserting the circuit board 30 into the metal case 12 is prepared in advance. At the center of the jig 42, a groove 44 having a width into which the metal case 12 is loosely fitted is provided. A pair of wall portions 46 of the jig 42 forming the groove 44 are provided with magnets 48. Are arranged respectively. After the metal case 12 is pressed, the metal case 12 is put into the groove 44 of the jig 42, and a magnetic force is applied to the metal case 12 by a pair of magnets 48 installed on the jig 42, so that the metal case 12 is cantilevered. The distal ends of the two side walls 16 and 18 are opened within a range of elastic deformation. As a result, the metal case 12 is deformed so that the opening 12A side of the metal case 12 is slightly widened.
[0027]
That is, as shown in FIG. 5 showing a state in which the circuit board 30 is inserted, the side wall 16 is pulled in the direction A and the side wall 18 is pulled in the direction B by magnetic force, and the space between the side walls 16 and 18 is widened. When the circuit board 30 is dropped by its own weight into the opening 12A of the metal case 12 in a state where the space between the side wall 16 and the side wall 18 is widened and the circuit board 30 is easily inserted, the protrusions 20B, The circuit board 30 is inserted into the metal case 12 while being guided by the first protrusion 20A and the second protrusion 22A.
[0028]
Next, for example, by taking out the metal case 12 from the jig 42 and releasing the magnetic force applied to the metal case 12, the opening amount of the opening 12 </ b> A returns to the size before entering the groove 44, and the circuit board 30. 6 shows a state in which is inserted into the metal case 12. That is, the projection 20B provided on the piece 20 near the opening 12A of the metal case 12 engages with the recess 30A provided on the end of the circuit board 30.
As described above, the circuit board 30 is housed in the metal case 12 formed by the single metal plate 40, and the shielded electronic component 10 is completed.
[0029]
Next, the operation of the electronic component 10 of the present embodiment and the method of assembling the same will be described.
The top plate 14 of the metal case 12 applied to the present embodiment has a pair of horizontal sides 14A facing each other and a pair of vertical sides 14B extending in a direction intersecting the horizontal sides 14A, and has a rectangular shape. It is formed. The two side walls 16 and 18 are formed by being bent at the pair of lateral sides 14A of the top plate 14 and extending substantially in the same direction. Further, the side walls 16 and 18 on both sides of the side walls 16 and 18 extending crossing the horizontal side 14A are bent against the side walls 16 and 18 respectively, and extend along the pair of vertical sides 14B and face each other. In the form, two sets of two pieces 20 and 22 are provided.
[0030]
Therefore, one metal plate 40 includes not only the top plate 14 and the two side walls 16 and 18 but also two pairs for forming another side wall intersecting the two side walls 16 and 18. It has two pieces 20 and 22. Further, the sum of the lengths W1 and W2 of the two pieces 20 and 22 facing each other is made longer than the length W of the vertical side 14B of the top plate 14, so that the tip sides of the two pieces 20 and 22 are mutually It is designed to overlap.
That is, the tip sides of the two pieces 20 and 22 overlap with each other, so that the other side wall is formed and the metal case 12 is formed by one metal plate 40, and the circuit board 30 is formed in the metal case 12. The electronic component 10 is stored and shielded.
[0031]
As described above, by projecting the pieces 20 and 22 for forming the other side walls arranged to intersect with the side walls 16 and 18 from the two side walls 16 and 18 connected to the top plate 14, the conventional technique is achieved. The material collection is more efficient than the metal case 12 and the material collection is optimized, and the material yield is improved. As a result, the amount of material to be discarded when manufacturing the metal case 12 is reduced, so that not only the material cost can be reduced, but also the environment is excellent.
Furthermore, by making the punching shape efficient so that the material yield is improved, the die cost can be reduced as the small punching die becomes a small punching shape that can be pressed, and the total manufacturing cost can be reduced. Cost reduction can be achieved.
[0032]
On the other hand, in the present embodiment, a step 20C is formed on the piece 20 and overlaps the piece 22 on the tip side of the piece 20 from the step 20C. Also, a first protruding portion 20A is formed on the piece portion 20, and a second protruding portion 22A sandwiching the circuit board 30 with the first protruding portion 20A is formed on the piece portion 22.
That is, since the position of the circuit board 30 is regulated by being sandwiched between the first projecting portion 20A and the second projecting portion 22A, the circuit board 30 is inserted into the metal case 12 after the circuit board 30 is inserted into the metal case 12. As there is no need to take any means for fixing the metal case 12 or to insert the mold case supporting the circuit board 30 into the metal case 12 as in the prior art, the manufacturing cost for manufacturing the mold case also increases. Will be reduced.
[0033]
On the other hand, in the present embodiment, concave portions 30A are provided at both end portions of circuit board 30, and convex portions 20B that engage with concave portions 30A are provided on one portion 20.
In other words, by providing the convex portion 20B which engages with the concave portion 30A provided on the circuit board 30 on the piece portion 20, a force is applied so that the opening 12A of the metal case 12 is slightly opened by utilizing the elastic deformation of the metal. With the simple operation of inserting the circuit board 30 in the state and then releasing the force to eliminate the extra opening of the opening 12A, the concave portion 30A of the circuit board 30 and the convex portion 20B of the piece 20 are engaged. Thus, it is possible to prevent the circuit board 30 from dropping out of the metal case 12.
[0034]
Therefore, it is not necessary to bend the retaining claws protruding from the metal case as in the prior art, and the manufacturing cost is further reduced. Further, in the related art, since the retaining claw is bent by about 90 ° at this time, there is a possibility that a crack may enter the bent portion of the retaining claw and the retaining claw may come off from the metal case. In other words, if the metal case is in such a state, the product is regarded as defective. Therefore, in the present embodiment, it is possible to reduce the manufacturing cost as the number of defective products is reduced and the product yield is improved.
[0035]
Next, the result of comparing the area of the unnecessary part between the metal case 112 of the related art and the metal case 12 of the present embodiment will be described below.
FIG. 8 is an overall view of a metal case 112 disclosed in Japanese Patent Application Laid-Open No. H11-220284, which is a prior art, and FIG. 9 is a developed view of the conventional metal case 112. The metal case 112 has a structure in which not only the pieces 120 and 122 protrude from the two side walls 116 and 118, respectively, but also the piece 124 protrudes from the top plate 114 to form the side wall 126. I have.
[0036]
The height of the metal case 112 is H, the width is L, the depth is W, and the length of the two pieces 120 and 122 forming the side wall 126 of the metal case 112 is 0.4 W. In the case where the metal case 112 of the related art is formed by punching and forming a plate-shaped metal material by press working, an unnecessary portion is a portion indicated by a hatched portion S and is 4 × H (H− 0.4 W).
Specifically, when the width L is 30 mm, the height H is 20 mm, and the depth W is 10 mm, the area of the unnecessary material is 1280 mm ² .
[0037]
On the other hand, when the metal case 12 according to the present embodiment, in which the external dimensions of the finished product are the same as the metal case 112 of the related art, is similarly formed by punching and molding a plate-like metal material by press working. 7, assuming that the length of each of the two pieces 20 and 22 constituting the side wall of the metal case 12 is 0.6 W, the area of the hatched portion S is 2 × 0.6 W ^2. It becomes.
Specifically, in the case of a metal case having the same dimensions as the above-described conventional metal case 112, the area of the unnecessary material is 120 mm ^{2, which} is about 1/10 of the conventional technology.
[0038]
Note that the unneeded shaded portion S is the same in both developed shapes when 4H (H−0.4W) = 1.2W ² , so that the range where H / W ≧ 0.78 is satisfied. Thus, the area of the hatched portion S, which is an unnecessary part, in the metal case 12 according to the present embodiment is smaller than that in the metal case 112 of the related art.
[0039]
On the other hand, in the above embodiment, a steel plate is used as the metal material, but other metal materials such as copper and aluminum having a shielding effect may be used. Furthermore, in the above-described embodiment, the opening is slightly opened by the magnet when the circuit board is inserted into the metal case, but the opening is manually opened by an operator, opened by suction with air, or opened by a machine. You may.
On the other hand, in the above embodiment, the electronic component is a DC / DC converter, but the present invention can be applied to other electronic components requiring a shield.
[0040]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the electronic component and the assembling method of an electronic component of this invention, the manufacturing cost for processing and manufacturing a metal case can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view of an electronic component according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the electronic component according to the embodiment of the present invention.
3A and 3B are diagrams showing an electronic component according to an embodiment of the present invention, wherein FIG. 3A is a plan view, FIG. 3B is a front view, and FIG. 3C is a right side view; (D) is a left side view.
FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;
FIG. 5 is a view showing a state in which a metal case applied to the electronic component according to one embodiment of the present invention is placed in a jig, and is a view in which the metal case is partially cut away.
FIG. 6 is a view showing a state in which a metal case applied to the electronic component according to one embodiment of the present invention is taken out of the jig, and is a view in which the metal case is partially cut away.
FIG. 7 is a developed view showing a strip of a metal case applied to the electronic component according to the embodiment of the present invention.
FIG. 8 is a perspective view of an electronic component according to the related art.
FIG. 9 is an exploded view showing a strip of a metal case applied to an electronic component according to the related art.
[Explanation of symbols]
REFERENCE SIGNS LIST 10 electronic component 12 metal case 14 top plate 16, 18 side wall 20, 22 piece 20 A first protrusion 20 B protrusion 22 A second protrusion 30 circuit board 30 A recess

Claims (2)

An electronic component in which a circuit board is housed and shielded in a metal case formed by a single metal plate,
A top plate formed in a rectangular shape having a pair of lateral sides facing each other and a pair of vertical sides extending in a direction intersecting these lateral sides,
Two side walls formed by being bent at a pair of lateral sides and extending along substantially the same direction as each other;
Two pieces which are each bent at the side of the side wall extending crossing the horizontal side and extend along the vertical side and opposite to each other,
The one metal plate is provided,
A concave portion is provided on the circuit board, and a convex portion engaging with the concave portion is provided on at least one of the two pieces,
A step is formed on at least one of these two pieces, and the two pieces overlap each other on the tip side of the piece from the step,
An electronic component, wherein a first protruding portion is formed on one of two pieces, and a second protruding portion sandwiching a circuit board with the first protruding portion is formed on the other piece . Forming a metal case having two side walls connected to the top plate and two pieces each extending from these side walls, one end of which is an opening,
Thereafter, a force is applied to the metal case to deform the metal case within the range of elastic deformation so that the opening side of the metal case is expanded, and in this state, the circuit board in which the concave portion is formed in advance is opened. From the side into the metal case,
Next, a method of assembling an electronic component, comprising releasing a force applied to a metal case to engage a protrusion provided in advance on a piece with a recess of a circuit board.

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