JPH07106147A - Surface packaged inductor - Google Patents

Abstract

PURPOSE:To provide a surface packaged inductor capable of being mounted and adsorbed onto an automated component mounting apparatus. CONSTITUTION:In a surface packaged type inductor, a E-type closed magnetic path is constructed by winding a coil winding 26 around a coiled bobbin 1, and assembling two E type magnetic cores 21 each constructing a central magnetic leg 22 and side magnetic legs 23, 24 both comprising a magnetic material facing them each other such that magnetic leg tip ends are connected with each other. A mounting/adsorbing cover 35 is constructed which is yielded by molding a non-magnetic/insulating material and includes a flat covering flat plane part 32 that covers a bobbin body upper part 31 on which the coil winding 26 is wound, side wall parts 33a, 33b that extend from the covering flat plane part 32 and interposed between a bobbin body 2 and the side magnetic legs 23, 24, stopper parts 34a, 34b which extend further to a bottom surface side of the side magnetic legs from the side wall part. Hereby, mounting/ adsorption is ensured at the covering flat plane part 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type inductor in which a closed magnetic circuit is constructed by combining a coil bobbin having fitting frames at both ends of a winding frame main body with magnetic cores constituting a central magnetic leg and side magnetic legs. More specifically, the present invention relates to a structure of a low-profile surface-mount inductor that is mounted on the upper surface of a winding frame main body around which a winding is wound so as to cover the flat non-magnetic cover and enables mount adsorption during automatic mounting. It is a thing.

[0002]

2. Description of the Related Art As electronic devices have become lighter, thinner, shorter and smaller in recent years, individual electronic parts are required to be thinner (lower in height). In particular, inductors (including transformers, choke coils, noise filters, etc.) There is a strong demand for large capacity and low profile.

Generally, in an inductor, a winding is divided into a primary side and a secondary side, and a closed magnetic path is formed by a magnetic core in the winding part, so that the primary side and the secondary side are formed. It is configured so as to exhibit a circuit function such as boosting voltage or increasing / decreasing current by mediating electromagnetic energy corresponding to the turns ratio, and it is an electronic component whose height is originally difficult to reduce.

However, a surface-mounting type inductor, in which a winding is wound around a thin non-magnetic coil bobbin having input / output terminals suitable for surface mounting, and then a magnetic core is combined, meets the above-mentioned demand for lower profile. Has become the current mainstream.

An example of the structure of the conventional surface mount inductor will be described in detail with reference to FIGS.

In FIG. 4, a coil bobbin 1 used in a conventional surface mount type inductor is formed by molding a synthetic resin or the like, which is a non-magnetic material, with a die or the like. That is, a winding portion 4 around which a winding such as an enamel wire is wound is provided on the outer peripheral portion of the winding frame main body 2 having a quadrangular prism shape, and a magnetic core having, for example, an E shape is provided inside. The insertion hole 3 into which the central magnetic leg is inserted is formed.

A first fitting frame 5 and a second fitting frame 6 are provided at the front end and the rear end of the winding frame main body 2 so as to sandwich the winding frame main body 2, respectively. Therefore, the bobbin main body 2, the first fitting frame 5 and the second fitting frame 6 form a substantially bobbin shape.

At this time, the fitting insertion hole 3 is also formed in the first fitting frame 5 and the second fitting frame 6 by integrally molding the coil bobbin 1, for example.

Further, the first fitting frame 5 and the second fitting frame 6 are
Has a first base 7 on the front side and a second base 8 on the rear side.
Are extended respectively, and an input / output terminal 11 is provided on a side surface 9 of the first base 7 in the fitting insertion hole direction at a position parallel to the fitting insertion hole 3 and at a right angle to the side surface.

Further, the input / output terminal 11 is formed so that its tip end portion is bent in an S shape from the twisting portion to the position of the bottom surface of the coil bobbin so as to come into contact with the mounting board during mounting.

Similarly, an input / output terminal 13 is also provided on the rear side surface 10 of the second base 8 so that the tip portion is bent and formed from the twisting portion.

Next, referring to FIG. 5, in the conventional surface mount type inductor 20, after winding the coil 26 around the coil bobbin 1 and twisting the coil 26 to the input / output terminal 11, the central magnetic leg 22 of the E type magnetic core 21 is fitted. The side magnetic legs 23, 24 and I are fitted into the mounting holes 3
A closed magnetic circuit is formed together with the die core 25.

In the conventional inductor structure described above, the wound winding portion 4 is generally left exposed or wound with vinyl tape once or twice.

In this respect, the above conventional surface mount type inductor 2
In the structure of No. 0, when an attempt is made to perform mount suction by the suction portion of the automatic component mounting apparatus for mounting the surface mount inductor etc., since the winding cross section is circular, the winding frame is wound. Since the upper part of the main body is not flat, this action is difficult and the winding part may be damaged.
It is not suitable for automatic mounting on an electronic circuit board or the like by the automatic component mounting apparatus.

Further, no electrical insulation or mechanical protection is provided from the external environment, etc. Therefore, damage to the winding portion causes physical damage to the inductor function or other electronic parts. There was a risk that an electrical short circuit with

Therefore, in the conventional surface mount type inductor, particularly in the inductor generating a high voltage, the above mounting method,
Considering the usage pattern, for automatic mounting and reliability improvement,
As shown in FIG. 6, a cover 29 made of synthetic resin covering the winding portion and its surroundings so as to ensure electrical insulation of the winding portion.
Is mounted on the coil bobbin 1 on which the winding is wound, and then the magnetic cores (the E-shaped magnetic core 21 and the I-shaped magnetic core 25 having the side magnetic legs 23 and 24 and the central magnetic leg 22) are fitted and shown in FIG. A surface mount inductor 30 having such a structure has been devised.

[0017]

Generally, electronic components are being automatically mounted on a mounting substrate such as an electronic substrate, and an automatic component mounting apparatus in which an inductor or the like is mounted is attached to a nozzle tip by a suction nozzle. The mounted inductor is sucked (called mount suction) and moved to a predetermined position. However, in the conventional surface mounted inductor in which the upper part of the bobbin body is not flat, the sucking force becomes weak as described above. ,
Easy to drop off. Therefore, conventionally, there is a problem that a so-called hand mount is inevitable.

Further, as shown in FIG. 7, a synthetic resin cover 29 for covering the winding portion and its periphery is attached to the coil bobbin 1 on which the winding is wound, and then the magnetic cores 21 and 25 are fitted. In the surface mount inductor 30 having the structure described above, the cover 29 made of synthetic resin is extended to the base part, so that the height of the surface mount inductor increases by the thickness. However, there is a problem that it is against the height reduction.

Further, the cover 29 made of synthetic resin must be mounted before fitting the magnetic core to the coil bobbin 1, and the mounting step must be added during the assembly process of the conventional surface mount inductor. It is necessary to change the assembly line.

The present invention has been made in view of the above circumstances, and by mounting a mount adsorption cover formed by molding a non-magnetic / insulating material on a winding frame main body around which a winding is wound, While maintaining the low profile of surface mount inductors,
The present invention provides a surface-mount inductor that realizes automatic mounting (automatic mounting) and that can be mounted even after assembly is completed by forming the cover with a soft synthetic resin.

[0021]

According to the present invention, there is provided a winding frame main body in which a fitting insertion hole for inserting a magnetic core is formed, and a winding is wound outside, and a winding frame main body at both ends. A central magnetic leg and side magnetic legs made of a magnetic material are formed by winding a coil bobbin having a fitting frame to be narrowed and a base supporting the fitting frames at both ends and having input / output terminals respectively. In a surface-mounting inductor in which a closed magnetic circuit is formed by combining the magnetic cores that form the above, a flat cover plane portion that covers the upper surface of the winding frame body around which the winding is wound, and a flat cover plane portion that extends from the cover plane portion. A non-magnetic / insulating material having a side wall portion interposed between the winding frame main body and the side magnetic leg, and a locking portion extending from the side wall portion to the bottom side of the side magnetic leg is molded. We provide a surface-mount inductor that is equipped with a mount adsorption cover It allows furthermore is intended to achieve the above object by the mounted suction cover in the surface-mount inductor to provide a surface mount inductors, characterized in that it consists of a soft synthetic resin material.

[0022]

In the present invention, since the mount suction cover having the flat covering flat surface covers the upper part of the winding frame main body around which the winding is wound, the suction nozzle tip of the automatic component mounting apparatus is surface-mounted. Adhesion is ensured on the flat portion of the cover of the mold inductor without air leakage, and the mount is securely attracted.

Further, since the side wall portion of the mount suction cover is interposed between the winding frame main body around which the winding is wound and the side magnetic leg, electrical insulation between the magnetic core and the winding is ensured. To do.

The engaging portion extending to the bottom side of the side magnetic leg of the mount attraction cover comes into contact with the bottom side of the side magnetic leg to form a crank shape to support the mount attraction cover on the surface mount inductor. Fix it.

The mount suction cover has a size that fits within the width between the fitting frames (winding portions) arranged at both ends of the winding frame body (if the size covers the fitting frame and covers the fitting frame, the side magnetic leg If the top of the wound winding is lower than the height of the mounting frame, the mount suction cover will not increase the height of the surface-mounted inductor.

Further, in the surface mount inductor in which the mount suction cover is made of a soft synthetic resin material,
The mount suction cover can be plastically deformed to some extent.

Therefore, the mount suction cover is formed into a U-shape and is wound around the side magnetic leg and the bobbin body of the surface-mounted inductor after assembly is completed without bending the portion corresponding to the locking portion in advance. After being inserted into the gap with the wound winding, it is possible to bend it appropriately to form the locking portion.

If a flexible material such as epoxy resin which is a soft synthetic resin is used as the material, the bent portion at the boundary between the locking portion and the side wall portion can be extended and inserted into the gap. it can.

Therefore, according to the above two methods, it is not necessary to previously mount the mount suction cover on the coil bobbin before fitting the magnetic core.

[0030]

Embodiments of the present invention will be described in detail with reference to the drawings. Incidentally, the same parts as those of the above-mentioned conventional example are denoted by the same reference numerals.

FIG. 1 is an exploded perspective view for explaining the structure of a surface mount inductor according to the present invention, and FIG. 2 is a perspective view after completion of a state where a mount suction cover is attached. 3A is a cross-sectional view taken along the line AB in FIG. 2, and FIG. 3B is a state in which a mount suction cover made of a soft synthetic resin material is mounted on the surface-mounted inductor after completion of assembly. FIG.

The coil bobbin used in this embodiment is the same as the coil bobbin 1 shown in FIG. 4, and has a bobbin body in which a fitting insertion hole 3 for inserting a magnetic core is formed and a winding is wound outside. 2, a first fitting frame 5 and a second fitting frame 6 for narrowing the winding frame main body 2 at both ends, and input / output terminals 11 and 13 for supporting the fitting frames at the both ends, respectively. It has a first base 7 and a second base 8.

The surface-mounting inductor 40 includes two E-type magnetic cores 21 which are formed by winding the coil 26 on the coil bobbin 1 as shown in FIG. 1 to form a central magnetic leg 22 and side magnetic legs 23 and 24 made of a magnetic material. A day-shaped closed magnetic circuit is formed by combining the magnetic legs so that the tips of the magnetic legs are connected to each other, and a flat cover plane portion 32 that covers the upper portion 31 of the winding frame main body around which the winding 26 is wound, Side wall portions 33a, 33b extending from the covering plane portion 32 and interposed between the winding frame body and the side magnetic legs.
And a mount suction cover 35 formed by molding a non-magnetic / insulating material having locking portions 34a, 34b extending from the side wall portion to the bottom side of the side magnetic leg. Has become.

The coil bobbin 1 is a phenol resin,
A synthetic resin such as polyethylene terephthalate or polybutylene terephthalate is used as a material, which is integrally formed by molding the synthetic resin with a mold or the like. The bottom of the first base 7 and the second base 8 has a reel body. 2 and lead terminal 1
A cut groove 36 for leading the winding between 1 and 13 is arranged between each input / output terminal.

The mount suction cover 35 is not particularly specified as to the material other than the non-magnetic / insulating material, but the synthetic resin or the like is usually suitable. Further, the width dimension W of the mount suction cover is equal to the distance between the fitting frames 5 and 6, that is, the front-rear width of the winding region, and the dimension X between the side wall portions 33a and 33b is equal to the left-right maximum width of the winding region. And side magnetic legs 23, 24
The dimensions fit in between. Height Z is side magnetic leg 2 when mounted
The dimensions are such that the surfaces of the engaging portions 34a, 34b come into contact with the bottom surfaces of 3, 24 and are approximately equal to the height of the fitting frames 5, 6.

The extension length Y of the extended locking portion is set to be equal to or less than the lateral width t of the side magnetic leg. However, it is necessary to secure a dimension necessary for the mounting mechanism 35 to be mounted such that the mount suction cover 35 does not easily come off from the inductor body due to the effective working of the locking mechanism. 0.5 for small surface mount inductors
It suffices to secure about mm.

The thickness d of the mount suction cover 35 has only to be strong enough not to be deformed by the suction force at the time of suctioning the mount to cause a trouble in the suction state.

Therefore, it may be extremely thin depending on the material used.

In the surface mount type inductor 40 having the mount suction cover 35 shown in FIG. 2, the upper surface of the inductor is flat, and if the tip of the suction nozzle is brought into contact therewith, the mount suction can be performed without air leakage. It is clear that it will happen.

As is clear from the sectional view taken along the line AB of FIG. 3, the main mount suction cover 35 covers the winding region so as to divide the side magnetic legs 23, 24 and the winding 26. Therefore, it also has the effect of improving the insulation between them.

Next, in the surface mount inductor according to the second aspect of the present invention, the mount suction cover 35 is made of a soft synthetic resin material, and can be plastically deformed to some extent.

Therefore, as shown in FIG. 3B, the mount suction cover 35 'is formed in a U shape so that the portions corresponding to the engaging portions 34a and 34b are not bent and assembled in advance. Side magnetic leg 2 of surface-mounted inductor after completion
After being inserted into the gap between the winding wire 3 and 24 and the winding wire 26 wound around the winding frame body, it is possible to form a locking portion by appropriately bending the side magnetic legs 23 and 24 as shown by arrows. Become.

Further, if the mount suction cover is made of a flexible material such as a soft synthetic epoxy resin, the engaging portions 34a, 34b and the side wall portions 33a, 3a, 3b.
It can be inserted into the gap by extending the bent portion of the boundary of 3b.

Therefore, the mount suction cover 3
It is not necessary to previously mount 5'on the coil bobbin 1 before magnetic core fitting, and it is possible to easily mount it on the finished product after magnetic core fitting.

It should be noted that the magnetic core in this embodiment has an EE type structure in which two E type magnetic cores are combined, but it is not limited to this, and for example, a Japanese type integrated magnetic core or Of course, it may be an EI type in which an E-type magnetic core and an I-type magnetic core are combined, or an FF type in which two F-type magnetic cores are combined.

Needless to say, the magnetic core material is a magnetic material such as ferrite, silicon steel plate, permalloy, or dust core.

[0047]

The surface mount type inductor according to the present invention is
Since it is configured as described above, it has the following effects.

(1) Since the mount suction cover is mounted on the upper part of the winding frame main body around which the winding is wound, there is an excellent effect that the mount suction by the automatic component mounting apparatus can be surely performed.

(2) Even if the mount suction cover is attached, the height of the inductor does not change, and there is an excellent effect of meeting the demand for a low profile.

(3) The mount adsorption cover made of a soft synthetic resin material has an excellent effect that it can be easily attached to a finished product after the magnetic core is fitted.

[Brief description of drawings]

FIG. 1 is an exploded perspective view for explaining a configuration of a surface mount inductor according to the present invention.

FIG. 2 is a perspective view after completion of a state where a mount suction cover is attached.

FIG. 3A is a cross-sectional view of the surface mount inductor taken along line AB, and FIG. 3B is a view showing a mount suction cover made of a soft synthetic resin material mounted on the surface mount inductor after assembly is completed. It is sectional drawing of the state which does.

FIG. 4 is a perspective view of a coil bobbin used in a conventional surface mount inductor.

FIG. 5 is a perspective view of a conventional surface mount inductor.

FIG. 6 is a perspective view of a synthetic resin cover mounted on a conventional surface mount inductor.

FIG. 7 is a perspective view of a conventional surface mount inductor with a synthetic resin cover attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 coil bobbin 2 winding frame main body 3 fitting insertion hole 4 winding part 5 first fitting frame 6 second fitting frame 7 first base 8 second base 9 side face in the fitting hole direction of the first base 10 Side surface of the two bases in the direction of the insertion hole 11, 13 Input / output terminals 20, 30, 40 Surface mount type inductor 21 E type magnetic core 22 Central magnetic leg 23, 24 Side magnetic leg 25 I type magnetic core 26 Winding 29 Made of synthetic resin Cover 31 upper part of reel main body 32 flat surface portion 33a, 33b side wall portion 34a, 34b locking portion 35, 35 'mount suction cover 36 notch groove W width dimension of mount suction cover X side wall portion dimension Z height dimension Y Extension length of locking part t Lateral width of magnetic leg on the side d Thickness of mount suction cover

Claims (2)

[Claims] 1. A winding frame main body having an insertion hole into which a magnetic core is inserted and having a winding wound on the outside, and a mounting frame for narrowing the winding frame main body at both ends. Winding a coil bobbin having a base that supports the fitting frames at both ends and is provided with input / output terminals, respectively, and combine magnetic cores that form a central magnetic leg and side magnetic legs made of a magnetic material. In a surface-mounted inductor in which a closed magnetic circuit is formed by, a flat covering flat surface portion covering the upper surface of the winding frame main body on which the winding is wound, and a space between the winding frame main body and the side magnetic leg extended from the covering flat surface portion. A mount suction cover formed by molding a non-magnetic / insulating material having a side wall part interposed between the side wall part and a locking part extending further from the side wall part to the bottom side of the side magnetic leg. A surface mount inductor characterized by 2. The surface mount inductor according to claim 1, wherein the mount suction cover is made of a soft synthetic resin material.