JP2002329619A - Surface mount type inductance element - Google Patents

Abstract

(57) [Summary] [Problem] To ensure insulation of a neighboring element by preventing the terminal from being entirely formed on the side surface of the outer core except for the necessary part, to improve the reliability of connection between the coil terminal and the terminal, The position can be easily set, and the terminals can be easily shared. SOLUTION: A drum core (1) provided with a collar portion (1a) at least at an upper end thereof and having a coil (2) mounted thereon, and an external core (3) provided on the outer periphery of the drum core and provided with terminals.
A plurality of terminal mounting holes (3a) in the outer core
A terminal (4) having a locking portion (4a) formed at the lower end is mounted in the terminal mounting hole, and the terminal (2a) of the coil is connected to the terminal on the upper surface of the outer core below the flange portion. Become.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an inductance element mainly used as a surface mount type transformer of an electronic device, and particularly to a small-sized and insulated element from other surrounding electronic parts, and to an integration efficiency. Related to the enhanced ones.

[0002]

2. Description of the Related Art In recent electronic devices, especially portable devices, electronic components to be mounted are increasingly required to be ultra-small and thin due to the trend toward miniaturization and weight reduction, and there is a strong demand for high integration of mounted electronic components. . Conventionally, as surface mount type inductance elements, Japanese Patent Application Laid-Open Nos. 10-32446 and 10-294
221 and JP-A-11-135331 have been proposed.

[0003]

However, since the metal terminals are entirely exposed on the side surfaces of the ring-shaped outer core, insulation of other adjacent electronic components becomes a problem, and the integration efficiency of these devices becomes problematic. Include the problem of worsening. In addition, if the coil terminals are not tied to each terminal, they tend to slip during reflow, and these metal terminals need to match the external shape of the ring-shaped outer core as the base material. It is difficult to form a part, and if it is attached to the ring-shaped outer core by caulking or the like, there is a problem of cracking.

Therefore, a first object of the present invention is to provide a terminal which does not have a terminal on a side surface of an outer core except for a necessary portion to take into consideration insulation from a proximity element, and a second object is to provide a coil terminal. And the third purpose is to make the position of the terminal easily determined,
Further, as a fourth object, the terminals can be easily shared.

[0005]

In order to solve the above-mentioned problems, in order to solve the above-mentioned problems, an inner core having at least a flange portion at an upper end and having a coil disposed therein and an outer core disposed around the inner core are provided. An external core provided with a plurality of terminal mounting holes, and a terminal mounted on the plurality of terminal mounting holes and forming a locking portion at a lower end and having an upper end exposed from the external core, The engaging portion can be achieved by connecting the terminal of the coil to the upper end of the terminal so that the terminal can be seen from the side below the outer core. If you do this,
The compact size makes it unnecessary to unnecessarily expose the terminals on the side of the outer core, making it easy to determine the position of the terminals. Can be easily soldered and reliability is increased. Furthermore, even if the thickness of the outer core changes, the terminals can be easily shared. Specifically, it is preferable that the inner core is formed in a drum shape having a flange at upper and lower ends, and a coil is wound between the flanges. In such a case, the coil can be wound by chucking the collar portion. It is preferable that the terminal is formed by a round pin as described in claim 3, and the locking portion has a flat head. In this way, the terminals can be easily created and can be shared even if the model is changed. As another configuration of the terminal, as shown in claim 4, the plurality of terminal mounting holes are formed in a rectangular shape, and the terminals mounted in the mounting holes are also formed in a rectangular cross section, Is preferably made of a hoop material. If you do this,
Temporary holding of the terminal is easy, and by making a cut in the portion of the outer core having a thickness for mounting the terminal, the terminal can be returned by spring back in the short direction, so that it can be permanently fixed. In such a terminal, the connection portion is preferably fixed with an adhesive as described in claim 6. By doing so, the movement of the terminal during reflow is suppressed, so that disconnection can be prevented. Preferably, the connection portion of the terminal is lower than the upper surface of the internal core. By doing so, insulation with the nearby members can be ensured, and a low profile can be achieved. Furthermore, at least a part of the lower collar portion of the inner core projects below the lower surface of the outer core, and at least a portion of the lower collar portion of the inner core is lower than the lower surface of the outer core. If the lower core portion of the inner core receives the outer core as a means for projecting downward, the mounting surface of the outer core has a simple shape and can be easily reflow soldered to the locking portion of the terminal. . As means for causing the upper collar portion of the inner core to protrude from the upper surface of the outer core, or for causing the upper collar portion of the inner core to protrude above the upper surface of the outer core, as shown in claims 10 and 11, If the upper flange of the internal core is made to protrude above the upper surface of the outer core by receiving the upper flange of the inner core on the upper surface of the outer core, the connection portion of the terminal is formed on the upper surface of the drum core. It can easily be prevented from projecting upward. According to another aspect of the present invention, there is provided an inner core having a flange portion disposed at an upper end thereof, a coil mounted on the inner core and previously wound with a self-fusing wire, and A plurality of terminal mounting holes are provided on the outer periphery, and an outer core is provided at the bottom such that a lower portion of the inner core is provided. A terminal having a stopper formed thereon and having an upper end exposed from the upper surface of the outer core, wherein the locking portion can be viewed from the side below the outer core, and a terminal of the coil is connected to the upper end of the terminal. However, the connection portion of this terminal can be achieved by a portion which is settled below the flange at the upper end of the inner core. If you do this,
Since the pre-wound air-core coil can be mounted on the inner core, the cost can be easily reduced, and the terminal does not need to be unnecessarily exposed on the side surface of the outer core, so that the position of the terminal can be easily determined. Since the side of the terminal locking portion is empty, soldering at the time of reflow can be easily performed, and reliability is increased. Specifically, it is preferable that the terminal is formed of a round pin and the locking portion has a flat head. If you do this,
Terminals can be easily created and shared even if the model is changed. As another configuration of the terminal, as set forth in claims 14 and 15, the plurality of terminal mounting holes are formed in a square shape,
The terminal mounted in the mounting hole may also be formed in a rectangular cross section, or the plurality of terminal mounting holes may be formed in a substantially rectangular shape when viewed from a plane, and the terminal may be formed of a hoop material. This makes it possible to easily hold the terminal temporarily, and to make a permanent cut back in the lateral direction by making a cut in the terminal mounting thickness portion of the outer core, so that permanent fixing can also be performed. Further, in such a terminal, the connection portion of the terminal is preferably fixed with an adhesive. By doing so, the movement of the terminal during reflow is suppressed, so that disconnection can be prevented. As the means for mounting and fixing the inner core, a step is provided below the inner core, and the inner core is received at the bottom of the outer core by the step. Alternatively, it can be achieved by providing the upper core portion to receive the upper collar portion except for the connection portion of the terminal on the upper surface of the outer core. This makes it possible to easily and easily mount and fix the inner core, the coil, and the outer core.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below based on embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of a surface mount type inductance element having a round pin type terminal as a first embodiment of the present invention. FIG. 2 is a plan view of FIG. FIG. 3 is an enlarged sectional view of an essential part of FIG. FIG. 4 is an enlarged sectional view of an essential part of a first modification of FIG. FIG. 5 is FIG.
It is an expanded principal part sectional view of the 2nd modification. FIG. 6 is an enlarged sectional view of a main part of a modification of FIG. FIG. 7 is a longitudinal sectional view of a surface mount type inductance element having a hoop type terminal according to a second embodiment of the present invention. FIG. 8 is a plan view of FIG. FIG. 9 is an enlarged perspective view of an essential part of FIG. FIG.
FIG. 13 is a longitudinal sectional view of a surface-mounted inductance element in which the structure of an inner core is changed as a third embodiment of the present invention. FIG. 11 is a plan view of FIG. FIG. 12 is an enlarged sectional view of an essential part of FIG. FIG. 13 is an enlarged sectional view of an essential part of a modification of FIG. FIG. 14 is a vertical cross-sectional view of a surface-mounted inductance element having a hoop-type terminal according to a fourth embodiment of the present invention in which the structure of the inner core is changed.
FIG. 15 is a plan view of FIG. FIG. 16 is an enlarged perspective view of a main part of FIG.

FIG. 1 is a longitudinal sectional view of a surface-mount type inductance element having a round pin type terminal according to a first embodiment of the present invention. Ferrite drum core 1 with coil 2 wound
And an outer core 3 disposed on the outer periphery of the drum core 1 by bonding or the like. As shown in FIG. 2, the outer core 3 is formed in a substantially square ring shape when viewed from a plane, and has a square corner. Two terminal mounting holes 3a are provided facing each other, and a terminal 4 composed of a round pin crushed and flattened with the lower end 4a as a locking portion is mounted in the terminal mounting hole 3a from below,
After the upper end 4b protruding from the upper surface is slightly bent and temporarily fixed, the coil end 2a is peeled off and soldered, and further fixed thereto with a heat-resistant epoxy resin or the like so as not to move. Here, the upper end 4b may be crushed and stopped in place of bending. Here, the flat-bottomed lower end 4a of the terminal 4 slightly protrudes from the lower surface of the drum core so that reflow soldering can be facilitated by surface mounting on the printed wiring board H on the device side. As shown in the figure, the flattened lower end 4a of the terminal 4 is surface-mounted on the printed wiring board on the device side, so that reflow soldering can be easily performed.
In addition, a notch 3b is received on the side surface so that the solder can be wrapped around and the strength can be obtained, so that the solder can be seen from the side. The upper end 4b is designed so as not to protrude from the upper flange 1a, and is fixed with an adhesive made of a heat-resistant epoxy resin J so that the terminal 4 does not rotate. The flat head structure may be a normal flathead screw structure.

FIG. 4 shows a first modification of FIG. 1. The drum core 1 has an upper flange portion 1aa having a slightly larger diameter, and is mounted on the upper surface of the outer core 3. As shown in FIG. The terminal 4 has a flat-headed upper end 4aa brought to the upper surface of the outer core 3 and a lower end 4aa protruding from the lower surface of the core.
bb is bent to form a solder terminal for surface mounting. In this way, the terminal of the coil wound with a relatively thick wire can be spot-connected to the flat top surface of the upper end 4aa. Again, it is desirable that the upper end 4aa of the terminal 4 be fixed with the above-mentioned heat-resistant epoxy resin J.

FIG. 5 shows a second modification of FIG.
In this case, the number of turns can be increased by enlarging the interval between the collars of the drum core 11. The lower collar 11b is enlarged to receive the lower surface of the outer core 33. The side surface of the engaging portion 4a is viewed from the side 3b so that reflow soldering is easy. FIG. 6 shows a modified example of FIG. 5 in which the collar 1aa at the upper end of the drum core 12 has a large diameter and is hooked on the upper surface of the outer core 3. Here, of course, it is necessary to take into account the groove from which the terminal 2a of the wound coil 2 is drawn.

FIG. 7 illustrates a second embodiment of the surface mount type inductance element. Here, the same components as those described above are denoted by the same reference numerals, and description thereof is omitted. Here, as shown in FIG. 8, the terminal mounting hole 3e has a rectangular shape with rounded corners as viewed from a plane.
The terminal 44 has rounded edges M on both short sides and is fitted in the terminal mounting hole 3e with a spring property. As shown in FIG.
In addition, by making a cut 44c in the terminal mounting thickness portion of the ring core in the short direction, the terminal is restored by spring back at the time of mounting, so that once the terminal is mounted, there is no possibility that the terminal will come off, and the terminal can be permanently fixed. Further, one end 44a of the terminal 44 is bent so that it can be reflow soldered to a printed wiring board (not shown).
The other end 44b is provided with a wedge-shaped notch 44d, and is connected by press-fitting and clamping a terminal 22a from which the coil 22 made of spare solder or a relatively thick wire is stripped in advance. In addition, the terminal 44 is provided with a bulge 44e in the middle to prevent rattling. In this case, the connection is simple and the reliability is high, and since there is no soldering, there is no possibility that the connection portion will be separated during reflow. Although the terminal is made of a plate-shaped hoop material, a square rod-shaped terminal may be provided by providing a square through hole on the outside or the core.

Next, referring to FIG. 10, a third embodiment of the present invention will be described in which the inner core is provided with only a flange portion above, and a coil having a self-fusing wire wound thereon is mounted later. However, the members described in each of the above embodiments have the same reference numerals. That is, a self-fusing wire is attached to the inner core 13 made of ferrite having a T-shaped vertical section having a flange portion 1a at the upper end and a step portion 13b formed below, and attached to the core 1c of the inner core 13. An air core coil 23 wound in advance and an outer core 34 made of ferrite disposed on the outer periphery thereof by bonding or the like. The outer core 34 receives the step 13b of the inner core 13 at the bottom 3d. As shown in FIG. 11, it is formed in a substantially rectangular ring shape when viewed from a plane, and has two terminal mounting holes 3a opposed to the square corners. The lower ends of the terminal mounting holes 3a serve as locking portions 4a. A terminal 4 consisting of a round pin crushed and flat-headed is mounted from below, and the upper end 4b protruding from the upper surface is slightly bent and temporarily fixed, and then the coil end 2a is peeled off and soldered. J It is those formed by fixed so as not to move in. Here, the bottom of the locking portion 4a at the lower end of the flat head of the terminal 4 slightly projects from the lower surface of the inner core so that reflow soldering can be easily performed when the surface is mounted on the printed wiring board H on the device side. As shown in the enlarged cross-sectional view of the main part of FIG. 12, the flat-bottomed lower end 4a of the terminal 4 is surface-mounted on a printed wiring board on the device side, so that reflow soldering is easy, and strength is ensured so that the solder goes around. A notch 3b is received on the side surface so as to be easily obtained, and can be seen from the side. The upper end 4b is designed so as not to protrude from the upper brim portion 11a,
The terminal 4 is fixed with an adhesive made of a heat-resistant epoxy resin J so as not to rotate. Note that the flat head structure of the locking portion 4a may be a polygonal shape such as a square or a normal flathead screw structure.

FIG. 13 shows a first modification of FIG. 10. The inner core 13 has an upper flange portion 1aa having a slightly larger diameter, and is provided on the upper surface of the outer core 3 inside the terminal connection portion. The terminal 4 has a flat top 4
aa is brought to the upper surface of the outer core 3 and the lower end 4bb protruding from the lower surface of the core is bent to be a soldering terminal at the time of surface mounting. In this manner, in a coil wound with a relatively thick wire, the terminal can be spot-connected to the flat top surface of the upper end 4aa. Of course, in order to avoid disconnection of the coil end, it is desirable to consider the terminal lead-out groove 3c in the upper flange portion provided on the outer core or the inner core. In this case as well, it is desirable that the upper end 4aa of the terminal 4 be fixed with the heat-resistant epoxy resin J.

FIG. 14 illustrates a fourth embodiment of the surface mount type inductance element. Here also, the same members as described above are denoted by the same reference numerals and the description thereof is omitted,
It is the same as FIG. 7 except that the internal core has changed. Here, as shown in FIG. 15, the terminal mounting hole 3e has a substantially rectangular shape with rounded corners when viewed from a plane, and a terminal 44 made of a hoop material is used. The terminal mounting hole 3e has a spring property.
As shown in FIG. 16, the terminal 44 made of the hoop material is cut into the terminal mounting thickness portion of the outer core in the short direction as shown in FIG. Once the terminal is mounted, there is no risk that it will come off, and the terminal can be permanently fixed. Further, one end 44a of the terminal 44 is bent so that reflow soldering can be performed on a printed wiring board (not shown), and the other end 44b is provided with a wedge-shaped cutout 44d. Coil 2 consisting of
The terminal 23a from which the insulating coating 3 has been stripped off is connected by press-fitting and clamping. In addition, the terminal 44 is provided with a bulge 44e in the middle to prevent rattling. In this case, the connection is simple and the reliability is high, and since there is no soldering, there is no possibility that the connection portion will be separated during reflow. Although the terminal is made of a plate-shaped hoop material, a square rod-shaped terminal may be provided by providing a square through-hole in the outer core.

In each of the above-described embodiments, the adhesive J can be used together for fixing the terminal and for fixing each part of the outer core and the inner core, and the number of terminals is not limited to two. The present invention can also be applied to those used and those having two transformers and four terminals. The present invention can take various other embodiments without departing from the technical concept and characteristics thereof. for that reason,
The above embodiments are merely examples and should not be construed as limiting. The technical scope of the present invention is defined by the appended claims, and is not limited by the description. In each of the above embodiments, the adhesive J can also be used for fixing the terminals and for fixing the outer core and the drum core, and the number of terminals is not limited to two. Can also be applied to those having two transformers and four terminals. The present invention can take various other embodiments without departing from the technical concept and characteristics thereof. Therefore, the above-described embodiments are merely examples and should not be construed as limiting.
The technical scope of the present invention is defined by the appended claims, and is not limited by the description.

[0015]

According to the present invention, with the above-described structure, it is possible to prevent the terminal from being entirely provided on the side surface of the outer core except for the required portion, thereby taking into consideration the insulation from the proximity electronic element. The connection between the terminal and the terminal can be made reliable, the position of the terminal can be easily determined, and the terminal can be easily shared. And, by mounting the coil wound in advance on the inner core, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a surface-mount type inductance element having a round pin type terminal according to a first embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an enlarged sectional view of an essential part of FIG. 1;

FIG. 4 is a sectional view of a main part of a first modified example of FIG. 1;

FIG. 5 is an enlarged sectional view of a main part of a second modification of FIG. 1;

FIG. 6 is an enlarged sectional view of a main part of a modification of FIG. 5;

FIG. 7 is a longitudinal sectional view of a surface-mounted inductance element having a hoop-type terminal as a second embodiment of the present invention.

FIG. 8 is a plan view of FIG. 7;

FIG. 9 is an enlarged perspective view of an essential part of FIG. 7;

FIG. 10 is a longitudinal sectional view of a surface-mounted inductance element in which the structure of an inner core is changed as a third embodiment of the present invention.

FIG. 11 is a plan view of FIG. 10;

FIG. 12 is an enlarged sectional view of an essential part of FIG. 10;

FIG. 13 is a sectional view of a main part of a first modified example of FIG. 10;

FIG. 14 is a longitudinal sectional view of a surface-mounted inductance element having a different structure of an inner core and having a hoop-type terminal according to a fourth embodiment of the present invention.

FIG. 15 is a plan view of FIG.

FIG. 16 is an enlarged perspective view of a main part of FIG. 14;

[Explanation of symbols]

 1, 11, 12, 13 Inner core 2, 22, 23 Coil 3, 33, 34 Outer core 3a, 3e Terminal mounting hole 3b Cutout portion 4, 44 Terminal

Claims (18)

[Claims] 1. An inner core having a collar at least at an upper end and having a coil disposed therein, an outer core disposed on an outer periphery of the inner core and having a plurality of terminal mounting holes, and a plurality of the terminal mounting holes. A terminal which is attached to the hole and has a lower end formed with a locking portion and an upper end exposed from the outer core, wherein the locking portion can be viewed from the side below the outer core,
A surface-mount type inductance element in which a terminal of the coil is connected to the upper end of the terminal. 2. The surface mount type inductance element according to claim 1, wherein the inner core is formed in a drum shape having a flange at upper and lower ends, and a coil is wound between the flanges. 3. The surface-mounted inductance element according to claim 2, wherein the terminal is formed of a round pin, and the locking portion has a flat head. 4. The surface mount type inductance element according to claim 2, wherein the plurality of terminal mounting holes are formed in a rectangular shape, and the terminals mounted in the mounting holes are also formed in a rectangular cross section. 5. The surface mount type inductance element according to claim 4, wherein the plurality of terminal mounting holes are formed in a substantially rectangular shape when viewed from a plane, and the terminals are formed of a hoop material. 6. The surface mount type inductance element according to claim 2, wherein a connection portion of the terminal is fixed with an adhesive. 7. The surface mount type inductance element according to claim 2, wherein a connection portion of the terminal is lower than an upper surface of the inner core. 8. The surface mount type inductance element according to claim 2, wherein at least a part of a lower collar portion of the inner core projects below a lower surface of the outer core. 9. A lower collar of the inner core receives the lower surface of the outer core as means for causing at least a portion of the lower collar of the inner core to protrude below the lower surface of the outer core. 2. The surface-mounted inductance element according to 1. 10. The surface mount type inductance element according to claim 1, wherein an upper flange portion of the inner core projects above an upper surface of the outer core. 11. The surface of claim 10, wherein the upper collar of the inner core protrudes above the upper surface of the outer core by receiving the upper collar of the inner core on the upper surface of the outer core. Mounting type inductance element. 12. An inner core having a flange at an upper end thereof, a coil mounted on the inner core and having a self-fusing wire wound thereon in advance, and a plurality of terminal mounting holes provided on an outer periphery thereof. An outer core having a lower portion provided with a lower portion of the inner core at a bottom portion. The outer core is attached to the plurality of terminal mounting holes. A terminal exposed from the outer core, wherein the locking portion can be seen from the side below the outer core, a terminal of the coil is connected to the upper end of the terminal, and a connecting portion of the terminal is an upper end of the inner core. The surface-mounted inductance element according to claim 1, wherein the surface-mount inductance element is located below the flange portion. 13. The surface mount type inductance element according to claim 12, wherein said terminal is formed of a round pin, and said locking portion has a flat head. 14. The surface mount type inductance element according to claim 12, wherein the plurality of terminal mounting holes are formed in a square shape, and the terminals mounted in the mounting holes are also formed in a square cross section. 15. The surface-mounted inductance element according to claim 14, wherein the plurality of terminal mounting holes are formed in a substantially rectangular shape when viewed from a plane, and the terminals are formed of a hoop material. 16. The surface-mounted inductance element according to claim 12, wherein a connection portion of the terminal is fixed with an adhesive. 17. A step portion is provided below the inner core,
13. The surface-mounted inductance element according to claim 12, wherein the inner core is received at the bottom of the outer core by the step. 18. The surface mount type inductance element according to claim 12, wherein the upper flange portion receives the upper collar portion except for a connection portion of the terminal on an upper surface of the outer core.