JP2000021651A - Wire-wound surface mount electronic component and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a wasteful lead frame which and to enable the use of a heavy wire coil and a terminal with low resistance. SOLUTION: This component is equipped with a drum core 4 which is wound with a coil, a base which has the drum core 24 fixed on its top surface and is made of insulating resin, and a terminal 23 which is wound with the lead part of the coil. The terminal 23 is so structured that a clamp part 34 clamping the top and reverse surfaces of the base 22 and a bundle part 35 wound with the lead part of the coil, while being positioned on the base 22 by making the clamp part 34 clamp the base 22 are molded into a single body. the terminal 23 is fitted by clamping the base 22, so that the need for a lead frame is eliminated, and a material with low resistivity is usable. The bundle part 35 is positioned on the base 2, so that the thick-diameter coil can be wound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wound surface mount electronic component used for electronic equipment and a method for manufacturing the same.

[0002]

2. Description of the Related Art Small wound surface-mounted electronic components are used as power supply choke coils for portable audio equipment such as camcorders, MDs and CDs, or digital video cameras. Also, large wound surface mount electronic components are used as choke coils for DC / DC converters of notebook computers and choke coils for inverter circuits of liquid crystal backlights of notebook computers.

FIG. 14 shows a lead frame 1 used for manufacturing a conventional wire wound type surface mount electronic component. Terminal plates 2 are formed at regular intervals on the lead frame 1. The base 3 in which the terminal plates 2 are embedded is formed by integrally molding an insulating resin with the lead frame 1 inserted into a mold. Is done. The base 3 has a plate-like terminal 4 implanted on a side surface different from the side surface on which the terminal plate 2 is provided. The plate-like terminal 4 is implanted so as to extend within the range of the thickness of the base 3.

FIG. 15 shows the base 3 cut off from the lead frame 1 of FIG. This cutting is performed by cutting the terminal plate 2 from the lead frame 1. When the terminal plate 2 is cut, the terminal plate 2 extends outward from the side surface of the base 3.
Is bent into a substantially L-shape so as to extend below the lower surface of the base 3 to form a leg-shaped terminal 5.

FIGS. 16 and 17 show that a drum core 6 is fixed to the upper surface of the base 3 formed as described above by bonding, and then a winding 7 is wound around the drum core 6, respectively. Are small-sized wound surface-mounted electronic components 8 and 9. In the wound surface-mounted electronic component 8 shown in FIG. 16, the lead 7 a of the winding 7 is wound around the plate-like terminal 4 extending within the range of the thickness of the base 3. On the other hand, in the wire-wound surface mount electronic component 9 shown in FIG. 17, the leg portion 5 extending below the lower surface of the base 3 is
Is to be wound.

FIG. 18 shows a large wound type surface mount electronic component 10.
Is shown. This large wound surface mount electronic component 10 is provided by further providing a ring core 12 to an assembly 11 in which the drum core 6 in which the winding 7 is wound on the base 3 as described above. This suppresses a change in inductance due to magnetic saturation during energization.

The ring core 12 has an inner diameter larger than the outer diameter of the drum core 6, and has a predetermined gap G between the ring core 12 and the base 3 so as to cover the drum core 6. Glued to the top surface. And the drum core 6
To maintain a gap G between the ring core 12 and
The adhesive 13 is filled between them. Such a gap G is for reducing variation in inductance due to contact between the drum core 6 and the ring core 12.

[0008]

However, FIG.
In the small wound type surface mount electronic component 8 shown in FIG.
The distance D1 from the lower surface of the base 3 to the lower surface of the base 3 is short, and the lead 7a of the lead 7a cannot be made thicker around the plate-like terminal 4. For example, if the thickness of the base 3 is 0.
In the case of 5 mm, only a winding having a diameter of at most 0.2 mm can be wound.

On the other hand, in the small-sized wire-type surface mount electronic component 9 shown in FIG. 17, the leg-shaped terminal 5 extends below the base 3, and accordingly, the thick wire 7 is connected to the leg-shaped terminal 5. Can be wound around. For example, when the vertical length L1 of the leg terminal 5 is 0.8 mm, a winding having a diameter of up to 0.3 mm can be wound.

However, the wire-type surface mount electronic component 9 has a problem in that the leg-shaped terminal 5 extends below the base 3 and the overall height is increased. Further, since the leg-shaped terminal 5 is formed from the terminal plate 2 of the lead frame 1, there is a problem that the leg-shaped terminal 5 is wide and a mounting area of the electronic component 9 is required to be large.

In addition to the above, since all of the small wound surface mount electronic components 8 and 9 are formed from the lead frame 1, the terminals 4 and 5 are made of a material such as phosphor bronze having a spring property. Therefore, it is necessary to use a material having a high resistance, and the component has a large resistance. In addition, when the lead frame 1 is used, many of the parts are discarded, which wastes resources. Furthermore, it is difficult to secure the dimensional accuracy of the leg-shaped terminal 5 during bending after separation from the lead frame 1.

On the other hand, in the large wound type surface mount electronic component 10 shown in FIG. 18, the gap between the drum type core 6 and the ring core 12 cannot be regulated. Therefore, it is necessary to secure a stable gap G between them. Is difficult. For this reason, there is a problem in that the drum core 6 and the ring core 12 come into contact with each other, causing variations in inductance. Further, in the electronic component 10, a large amount of magnetic flux leaks in the direction of the upper surface of the drum core 6, and when the electronic component 10 is mounted on a multilayer wiring board, there is a problem that magnetic coupling easily occurs.

The present invention has been made in consideration of such conventional problems, and allows a thick winding to be wound without increasing the height, and uses a material having a low resistivity as a terminal. It is another object of the present invention to provide a small-sized wire-wound surface mount electronic component which can be used and does not use a wasteful lead frame.

Further, the present invention provides a large-sized wire-mounted surface-mounted electronic device capable of reliably preventing contact between a drum core and a ring core, causing no variation in inductance, and reducing leakage flux. The purpose is to provide parts.

A further object of the present invention is to provide a manufacturing method capable of suitably manufacturing these wound surface mount electronic components.

[0016]

According to a first aspect of the present invention, there is provided a wire-wound surface-mounted electronic component, comprising: a drum-type core on which a winding is wound; and the drum-type core fixed to an upper surface. A base made of an insulating resin, a holding portion for holding the upper and lower surfaces of the base, and a binding portion around which the lead portion of the winding is wound with the holding portion positioned on the base by holding the base. And a molded terminal.

In the present invention, the terminal is attached to the base by sandwiching the base between the terminal sandwiching portions. Thus, the terminals are independent of the lead frame and can be designed separately from the lead frame.
Therefore, the terminal can be formed from a material having a low resistivity, and a low RDC
The terminal can be formed with high precision.

Further, the entangled portion of the terminal is located on the base to which the drum core is fixed, and in this state, the lead portion of the winding is wound. This eliminates the need for a unique space in the height direction for winding the lead portion, allowing winding of a large-diameter winding and winding the large-diameter winding. Does not need to be extended below the base, and the overall height does not increase.

Further, in the structure in which the terminal sandwiches the base, the terminal does not protrude to the side of the base, and the mounting area can be reduced.

According to a second aspect of the present invention, there is provided a wound type surface mount electronic component, comprising: a drum core wound with a winding; a base made of an insulating resin to which the drum core is fixed on an upper surface; A terminal formed integrally with a clipping portion for clamping the lead, a binding portion around which the lead portion of the winding is wound in a state where the clipping portion is positioned on the base by clamping the base, and the periphery of the drum core. It has a ring shape surrounding, comprising a drum core and a ring core fixed to the upper surface of the base with a gap, and a positioning portion for positioning the drum core and the ring core so as to keep a predetermined gap. It is formed on the upper surface of the base.

In the present invention as well, a material having a low resistivity can be used as the terminal, and the whole does not become high even if a winding having a large diameter is wound. Further, in the present invention, since the positioning portion on the upper surface of the base positions the drum core and the ring core, a gap can be secured between them. Therefore, the drum core and the ring core do not come into contact with each other, and variations in inductance due to the contact are eliminated.

A third aspect of the present invention is the invention according to the second aspect, wherein a ring projection protruding inward is integrally formed at an upper opening end of the ring core.

According to the present invention, the ring projection projecting inward from the ring core prevents leakage of magnetic flux in the direction of the upper surface of the drum core. For this reason, leakage magnetic flux is reduced and high-density mounting can be performed, and magnetic coupling does not occur even when mounted on a multilayer wiring board.

A fourth aspect of the present invention is the invention according to the second aspect, characterized in that a notch portion for escaping the terminal is formed at a lower portion of the ring core.

According to the present invention, contact between the ring core and the entangled portion of the terminal is prevented by the escape cutout portion at the lower portion of the ring core. Therefore, the ring core can be provided on the base so as to overlap with the binding portion of the terminal, and the mounting volume can be reduced.

According to a fifth aspect of the present invention, in the second aspect of the present invention, the positioning portion projects from the upper surface of the base between the drum core and the ring core, thereby positioning both the drum core and the ring core. It is a positioning projection for positioning.

According to the present invention, since the positioning projections projecting from the upper surface of the base position the drum core and the ring core therebetween, a gap can be secured between the drum core and the ring core. In addition, since the positioning protrusion positions both the drum core and the ring core, the drum core and the ring core can be arranged on the base using the positioning protrusion as a guide, and the arrangement can be performed easily and reliably. .

According to a sixth aspect of the present invention, in the second aspect, the positioning portion is formed on the upper surface of the base so as to be stepped higher around the drum core, and the ring core is mounted thereon. The positioning step portion to be placed, wherein a fitting concave portion into which the positioning step portion is fitted is formed below the ring core.

According to the present invention, the ring core is placed on the positioning step on the upper surface of the base, so that the ring core and the drum-shaped core are positioned, so that a predetermined gap can be secured between them. In addition, since the ring core is provided with a fitting concave portion that fits into the positioning step portion and absorbs the height of the positioning step portion, even if the ring core is placed on the positioning step portion that is stepped up, The ring core does not become high.

The invention of claim 7 is the invention according to any one of claims 1 to 5, wherein the terminal and the base are provided with:
An engaging means for mutually engaging and fixing the terminal at a fixed position on the base is provided.

According to the present invention, since the terminal and the base are positioned by the engagement means, the terminal can be securely fixed to a fixed position of the base, and stable mounting can be performed.

In the method of manufacturing a wire-type surface mount electronic component according to the present invention, the upper and lower surfaces of the base are sandwiched between the terminal sandwiching portions, so that the terminal binding portion integrally formed with the sandwiching portion is positioned on the base. And, after fixing the drum core to the upper surface of the base, winding the winding around the drum core, winding the lead portion of the winding around the tying portion of the terminal, and tangling with the lead portion. And soldering the soldering portion.

In the present invention, the upper and lower surfaces of the base are sandwiched between the terminal sandwiching portions, and the base is attached, whereby the binding portion of the terminal is located on the base. As described above, since the lead portion of the winding is wound around the binding portion located on the base, a winding type surface mount electronic component that does not increase in height despite the use of a winding having a large diameter is manufactured. be able to.

According to a ninth aspect of the present invention, in the method of manufacturing a wire-wound surface mount electronic component, the upper and lower surfaces of the base are sandwiched between the terminal sandwiching portions, so that the terminal binding portion integrally formed with the sandwiching portion is positioned on the base. And, after fixing the drum core to the upper surface of the base, winding the winding around the drum core, winding the lead portion of the winding around the tying portion of the terminal, and tangling with the lead portion. A step of soldering the ring core and a base of the ring core so as to have a gap with the periphery of the drum-shaped core in a state in which a notch for escape provided at a lower portion of the ring core is opposed to the binding portion of the terminal. And a step of fixing to the upper surface of the substrate.

According to the present invention as well, it is possible to manufacture a wire-wound surface-mounted electronic component whose height does not increase despite the use of a wire having a large diameter. Further, in the present invention, since the escape cutout portion of the ring core is opposed to the entangled portion of the terminal, the ring core can be fixed on the base in a state where contact between the ring core and the entangled portion of the terminal is prevented.

The tenth aspect of the present invention is the invention according to the eighth or ninth aspect, wherein the entangled portion of the terminal protrudes above the lower flange portion of the drum core fixed to the base. After raising to an extent, the lead portion of the winding is wound.

In the present invention, since the terminal is entangled, the lead portion can be smoothly and easily wound around the entangled portion even if the winding has a large diameter. Further, since the binding portion of the terminal does not protrude from the lower flange portion of the drum core, the binding portion and the lead portion can be soldered without any trouble.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. In each embodiment, the same members are denoted by the same reference numerals and correspond to each other.

FIGS. 1 to 4 show a first embodiment of the present invention. This embodiment is applied to a small wound type surface mount electronic component 21 used as a power supply choke coil of a portable audio device such as a camcorder, an MD or a CD, or a digital video camera.

In this embodiment, as shown in FIG.
The base 22, a pair of terminals 23, and a winding 25 (FIG. 4)
(See (a)).

The base 22 is formed in a thin rectangular plate shape using an insulating resin. On the upper surface 22a of the base 22,
Terminal mounting portion 2 to which terminals 23 are respectively fitted
6, 26 and a positioning protrusion 27 as a positioning portion are formed.

The terminal mounting portions 26, 26 are located at a pair of opposing corners of the base 22, and are formed to have a planar rectangular shape lower than the upper surface 22a by the thickness of the terminal 23. . Recesses 29, 29 for preventing the terminal 23 from being displaced are formed in the side surfaces 22 b, 22 b of the base 22 at the respective terminal mounting portions 26, 26 forming portion by fitting the connecting piece 33 of the terminal 23. Have been. Also, on the upper surfaces of the respective terminal mounting portions 26, 26,
Engagement projections 28, 28 which engage with the engagement holes 36 of the terminal 23 are provided in a protruding manner.

The positioning projection 27 is formed on the upper surface 22 of the base 22 so as to form an arc centered on the central portion of the base 22.
a. In this embodiment, since the positioning protrusion 27 is provided on the base 22 so as to have a diameter including the terminal mounting portions 26, 26, the terminal mounting portions 2 are provided.
The positioning protrusions 27 are in a notched state in the formation regions 6 and 26.

An inner portion of the positioning projection 27 on the upper surface 22a of the base 22 serves as a core mounting portion 37 on which the drum core 24 is mounted. Therefore, the positioning protrusion 2
Numeral 7 constitutes a positioning part for positioning the drum core 24. In addition, when the present invention is applied to a second embodiment shown in FIGS. 5 to 8 to be described later, the positioning protrusion 27 is, as shown in FIG.
) To protrude between the
It functions as a positioning portion that positions both the drum core 24 and the ring core 41.

One corner of the base 22 is a notch 30 cut out along the thickness direction of the base, and the notch 30 is used as a reference when soldering, which will be described later. Is set.

Each of the pair of terminals 23 is formed of a conductive metal thin plate, and is formed by integrally molding the sandwiching portion 34 and the binding portion 35.

The sandwiching portion 34 is formed in a U-shape in which an upper sandwiching piece 31 and a lower sandwiching piece 32 are continuously connected by an up-and-down connecting piece 33, and the interval between the upper and lower sandwiching pieces 31, 32 is equal to that of the base 22. The thickness is substantially equal to the thickness of the terminal mounting portion 26. The terminal 23 is attached to the base 22 by the sandwiching portion 34 sandwiching the terminal attachment portion 26 of the base 22.

The upper sandwiching piece 31 has an engaging hole 36 with which the engaging projection 28 of the base 22 is engaged. The engagement hole 26 and the engagement protrusion 28 are engaged with each other to form an engagement means for fixing the terminal 23 at a fixed position on the base 22. Accordingly, the terminal 23 is securely fixed to the fixed position of the base 22 and does not shift in position, in combination with the fitting of the connecting piece 33 into the recess 29 as described above.

The lower holding piece 32 in the holding portion 34
Are exposed on the lower surface of the base 22, and by this exposure, contact terminals that are in contact with electrodes (not shown) of the wiring board and become conductive.

The binding portion 35 is connected to the upper holding piece 31 of the holding portion 34. The binding portion 35 is the upper sandwiching piece 31
From the upper sandwiching piece 31 so as to bend at an acute angle in the direction of the connecting piece 33, that is, in the direction away from the drum core 24 on the base 22. In this embodiment, the continuous length of the binding portion 35 is determined by fitting the terminal 2.
When the base 3 is attached to the base 22, as shown in FIG. 2 (b), the leading end of the entangled portion 35 is set in the plane of the base 22 so as to have a size that does not protrude from the base 22. I have. At the tip of the binding portion 35, a binding recess 35a cut out along the width direction of the plate is formed, and using the binding recess 35a as a guide, the lead portion 25a at the tip of the winding 25 is used. Is wound around the binding portion 35.

The drum type core 24 includes a winding shaft 38 and flanges 39 and 40 integrally formed on upper and lower ends of the winding shaft 38, and the winding 25 is wound around the winding shaft 38. The drum core 24 is formed of ferrite, which is an oxide magnetic material.

Next, the manufacturing procedure of this embodiment will be described. FIG. 2 shows a process of attaching the terminals 23 and the drum core 24, and FIG. 3 shows a process of winding the winding 25 around the drum core 24.

First, as shown in FIG.
Each terminal 23 approaches the terminal mounting part 26 from the left and right of
The terminal attaching portion 26 of the base 22 is sandwiched by the sandwiching portion 34. In this sandwiching, the engaging projection 28 of the base 22 is engaged with the engaging hole 36 of the sandwiching portion 34, and
Is fitted into the concave portion 29 on the side surface of the base.
Thereby, as shown in FIG. 2B, the terminal 23 is fixed at a fixed position of the base 22 with the base 22 sandwiched therebetween. The binding portion 35 of each terminal 23 extends toward the corner of the base 22, but is located on the base 22 so as to be in the plane of the base 22.

In the state of FIG. 2B, an adhesive (not shown)
Is applied on the core mounting portion 37, and then the lower flange portion 40 is formed.
The drum core 24 is fixed to the upper surface 22 a of the base 22 by bringing the drum core 24 into contact with the core mounting portion 37 and curing the adhesive. At this time, the drum core 24 is dropped so that the lower flange portion 40 is inserted into the arc-shaped positioning protrusion 27. As a result, as shown in FIG. 2C, the drum core 24 can be reliably fixed at a fixed position substantially at the center of the base 22.

After the fixing of the drum type core 24, FIG.
As shown in FIG.
5 is wound to form a coil. After the winding of the winding 25, the binding portion 35 of the terminal 23 is raised from the upper surface 22a of the base 22, as indicated by the arrow in FIG. This can be easily performed by using a jig not shown in the drawings, but is performed so that the binding portion 35 does not protrude above the lower flange portion 40 of the drum core 24.

Then, as shown in FIG.
5, the lead portion 25a at the beginning of winding and the lead portion 2 at the end of winding
5a is wound around the corresponding binding portion 35. In this winding, since the entangled portion 35 is caused,
And it can be easily performed. Then, the lead portion 25a
After the winding, the tip of the lead portion 25a is cut to obtain the state shown in FIG.

Thereafter, a plurality of bases 22 are mounted on a solder frame (not shown) so that the notch corners 30 of the base 22 face in the same direction, and flux soldering is performed. In this soldering, since the entangled portion 35 does not protrude above the lower flange portion of the drum core 24, only the entangled portion 35 and the lead portion 25a can be reliably soldered. Since the lead portion 25a and the binding portion 35 are firmly connected by such soldering, it is possible to manufacture the small-sized wire-type surface mount electronic component 21 of the present embodiment.

In such an embodiment, the terminal 23 is attached to the base 22 by sandwiching the pinching portion 34 of the terminal 23 with the terminal attaching portion 26 of the base 22.
There is no need to use a lead frame. For this reason, it is not necessary to consider the spring property of the terminal 23, and a material having low resistivity such as tough pitch steel can be used, and a low R
DC conversion becomes possible. Further, since the terminal 23 can be formed alone, the dimensional accuracy of the terminal 23 can be improved.

FIG. 4A shows an electronic component 2 according to this embodiment.
1, (b) shows the electronic component 8 of FIG. 16, and (c) shows the electronic component 8 of FIG.
Are compared side by side. In this embodiment, since the binding portion 35 of the terminal 23 around which the lead portion 25a of the winding 25 is wound is located on the base 22, for example, as shown in FIG.
The above-described winding 25 having a large diameter can be wound. Moreover, in order to wind the thick winding 7, it is not necessary to extend below the base 3 as in the case of the leg-shaped terminal 5 of (c), and the whole can be kept at the height of (b). Will not be.

FIGS. 5 to 8 show a second embodiment of the present invention. In this embodiment, the DC /
This figure shows an application to a large wound type surface mount electronic component 42 used for a choke coil for a DC converter, a choke coil for an inverter circuit of a liquid crystal backlight of a notebook personal computer, and the like. Therefore, in this embodiment, the ring core 41 is added to the assembly according to the first embodiment described above.

The ring core 41 uses the same ferrite as the ring core 24, and has a ring shape as a whole as shown in FIG. The ring core 41 has the same height as the drum core 24, but is formed to have a larger diameter than the drum core 24. For this reason, it is fixed to the base 22 so as to surround the drum core 24.

The escape notch 43 of the entangled portion 35 of the terminal 23 is formed below the ring core 41 so that the ring core 41 does not contact the entangled portion 35 of the terminal 23. Therefore, the ring core 41 is connected to the binding portion 3 of the terminal 23.
5, and the mounting volume of the electronic component 42 can be reduced.

A ring protruding piece 44 which is formed in a ring shape and protrudes inward is integrally formed at the upper open end of the ring core 41. The inner diameter of the ring projection 44 is larger than the outer diameter of the drum core 24, more specifically, the outer diameter of the upper flange 39 of the drum core 24. For this reason, even if the ring core 41 is arranged around the drum core 24, it is possible to maintain a predetermined gap between the ring core 41 and the drum core 24.

In this embodiment, a ring core 41 is attached to the assembly of the first embodiment. As shown in FIG. 6A, a terminal 23 is attached to a base 22 and a drum core is attached. 24 is fixed to the base 22, and the lead portion 35a of the winding 25 is connected to the terminal 23.
After the entangled portion 35 is wound and soldered, an adhesive 45 is applied to the upper surface 22 a of the base 22. The adhesive 45 fixes the ring core 41 to the upper surface 22a of the base 22, and is applied so as to be located around the drum core 24.

Then, the ring core 41 is lowered so as to surround the drum-shaped core 24 and abuts on the upper surface 22 a of the base 22, and the adhesive 45 is hardened to fix the ring core 41 to the base 22.
Stick to In mounting the ring core 41, the escape notch 43 is opposed to the entangled portion 35 of the terminal 23 on the base 22 to prevent the ring core 41 from coming into contact with the entangled portion 35.

The ring core 41 is fixed on the base 22 so as to be positioned outside the positioning projection 27 with reference to the positioning projection 27 projecting from the upper surface 22a of the base 22. That is, the positioning protrusion 27 is formed on the base 22 so as to be located between the drum core 24 and the ring core 41, and acts to position both the drum core 24 and the ring core 41.

By fixing the drum core 24 and the ring core 41 to the base 22 so as to sandwich the positioning projection 27 in this manner, they can be fixed at a fixed position. , A predetermined gap G (see FIG. 8) can be ensured.

FIG. 7 shows a process of filling the adhesive 46 between the ring core 41 and the drum core 24 after the ring core 41 is fixed as described above. As shown in FIG.
An adhesive 46 is applied at appropriate intervals so as to be stretched between the ring core 41 and the upper flange 39 of the drum core 24. Thereby, the adhesive 46 invades between the ring core 41 and the drum core 24. Thereafter, the adhesive 46 remaining on these upper surfaces is removed by a solvent, so that the winding type surface mount electronic component 42 shown in FIG.
And

FIG. 8 shows a cross section of the winding side electronic component 42 of this embodiment. The positioning projection 27 projecting from the upper surface 22a of the base 22 determines the positioning between the drum core 24 and the ring core 41. For this purpose, a gap G is secured between them. In addition, the drum core 24 and the ring core 41 are fixed to each other by an adhesive 46 filled between the drum core 24 and the ring core 41 so as to maintain a non-contact state. Therefore, the drum core 24 and the ring core 41 do not come into contact with each other, and variations in inductance due to the contact are eliminated.

Further, a ring projection 44 provided at the upper open end of the ring core 41 prevents leakage of magnetic flux in the direction of the upper surface of the drum core 24. For this reason, leakage magnetic flux is reduced and high-density mounting can be performed, and magnetic coupling does not occur even when mounted on a multilayer wiring board.

FIGS. 9 and 10 show a third embodiment of the present invention, which is another embodiment of a small-sized wound surface-mounted electronic component, in the order of manufacturing steps. In this embodiment, the terminal 23
Of the terminal 23 is longer.
As shown in FIG. 9B, when the upper and lower surfaces of the base 22 are sandwiched, the distal end of the binding portion 35 extends outward from the base 22.

Further, as shown in FIG.
Positioning step 47 stepped higher than the upper surface 22a
Are formed. The positioning step portion 47 has an arc-shaped locus as a whole, but the portion of the terminal mounting portion 48 to which the terminal 23 is mounted by sandwiching the base 22 is removed by cutting out the arc portion. .

In this embodiment, an inner portion of the positioning step 47 serves as a core mounting portion 37 for mounting the drum core 24 in a positioning state. On the other hand, the positioning step 47 itself acts to position the ring core 41 when the ring core 41 described later is placed thereon.

Further, the terminal mounting portion 48 on the upper surface 22a of the base 22 is provided with a stopper portion 49 for fixing the terminal 23 in a fixed position by contacting the upper sandwiching piece 31 of the terminal 23 from both ends. .

Also in this embodiment, although not shown, the sandwiching portion 34 of the terminal 23 is formed in a U-shape so that the base 22 can be sandwiched. Then, as shown by the arrow in FIG.
2 with the terminal 23 inclined at about 45 ° with respect to the terminal 2
The base 22 is sandwiched by the sandwiching portion 34 by bringing the 3 closer to the base 22.

As shown in FIG. 9B, the outer portion of the upper sandwiching piece 31 is fitted between the stopper portions 49, so that the terminal 23 is fixed to the base 22. At this time, the tip of the binding portion 35 of the terminal 23 extends outside the base 22. Also in such an embodiment, there is no need to use a lead frame, and the restriction by the lead frame is not imposed, and the terminal 2
3 can have a low resistivity and can be molded with high precision.

After the attachment of the terminals 23, as shown in FIG. 9C, an adhesive 50 is applied on the core mounting portion 37 to fix the drum core 24 to the base 22. At this time, by placing the drum core 24 inside the positioning step 47, the drum core 24 can be fixed at a fixed position.

Then, after winding the winding 25 around the drum core 24, the lead 25a of the winding 25 is wound around the binding portion 35 of the terminal 23 as shown in FIG. Also in this case, the lead portion 25a is wound around the binding portion 35 after the binding portion 35 of the terminal 23 is caused. In this embodiment, the leading end portion of the binding portion 35 extends outside the base 22, so that the winding around the lead portion 25a can be easily performed.

After the winding of the lead portion 25a, the tip of the lead portion 25a is cut along the surface of the binding portion 35. Thereafter, the entangled portion 35 and the lead portion 25a are soldered. After this soldering, as shown in FIG.
The leading end portion of the entangled portion 35 extending to the outside of 2 is cut and removed to obtain the wound surface mount electronic component 51.

In this embodiment, as in the first embodiment, the winding 25 having a large diameter can be used without increasing the overall height.

FIGS. 11 to 13 show a fourth embodiment of the present invention in which a large wound surface mount electronic component is obtained by adding a ring core 41 to the assembly of the third embodiment.

In the ring core 41 used in this embodiment, as shown in FIG.
A notch 43 for escape is formed at a lower portion, and a ring projection 44 protruding inward is formed at an upper open end. In addition, in the ring core 41 of the present embodiment, a fitting concave portion 52 is formed. The fitting recess 52 is formed in the lower part of the ring core 41, and its vertical dimension corresponds to the height of the positioning step 47 of the base 22.
7 can be fitted.

In this embodiment, as shown in FIG. 12A, the adhesive 45 is placed on the positioning step 47 of the base 22.
After coating, the ring core 41 is placed and fixed on the positioning step 47. The positioning step 47 is used to position the drum core 24 in the preceding stage.
In order to position the ring core 41 on the ring core 7 and position the ring core 41, the ring core 41 is also positioned. Therefore, the drum core 24 and the ring core 41
Are positioned by the positioning step 47, so that a gap can be reliably provided between them.

FIGS. 12 (b) and 13 show that the adhesive 46 is filled between the ring core 41 and the drum core 24 after the ring core 41 is fixed, similarly to the second embodiment. This is a linear surface mount electronic component 53. In the electronic component 53, the gap can be reliably provided between the drum core 24 and the ring core 41 by the positioning step portion 47, so that they do not come into contact with each other, as in the second embodiment. Variation in inductance can be eliminated.

In particular, in this embodiment, since the fitting recess 52 into which the positioning step 47 is fitted is formed in the lower portion of the ring core 41, the height of the positioning step 47 can be absorbed. For this reason, the ring core 41 does not become high, and the height as a whole does not increase.

[0086]

As described above, according to the first aspect of the present invention, since the terminals are independent of the lead frame, the terminals can be formed of a material having a low resistivity, and the RDC can be reduced. Can be molded with high precision. Also, a thicker diameter winding can be used without increasing the overall height.

According to the second aspect of the present invention, in addition to the above,
Since there is no contact between the drum core and the ring core, variations in inductance can be eliminated.

According to the third aspect of the present invention, since the magnetic flux leakage in the direction of the upper surface of the drum core is reduced, magnetic coupling does not occur and high-density mounting can be performed.

According to the fourth aspect of the invention, it is possible to prevent the ring core from coming into contact with the binding portion of the terminal.

According to the fifth aspect of the present invention, since both the drum core and the ring core are positioned, they can be easily positioned.

According to the sixth aspect of the present invention, the ring core and the drum core can be positioned without increasing the height of the ring core.

According to the seventh aspect of the present invention, the terminal can be securely fixed to the fixed position of the base.

According to the eighth aspect of the present invention, it is possible to manufacture a wire-wound surface-mounted electronic component whose height does not increase despite the use of a wire having a large diameter.

According to the ninth aspect of the present invention, a winding type in which a large diameter winding can be used but the height does not increase and the contact between the ring core and the binding portion of the terminal is prevented. Surface mount electronic components can be manufactured.

According to the tenth aspect of the present invention, the winding having a large diameter can be reliably wound around the binding portion of the terminal.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment of the present invention.

FIGS. 2A to 2C are plan views showing a terminal sandwiching step and a drum core fixing step in the first embodiment in the order of steps.

FIG. 3A is a front view of a step of causing a binding portion,
(B) is a plan view of a step of winding the lead portion around the binding portion,
(C) is a plan view of the final step of winding.

FIGS. 4A to 4C are front views in which the first embodiment and a conventional electronic component are compared side by side.

FIG. 5A is a perspective view of a ring core used in a second embodiment, and FIG. 5B is a longitudinal sectional view thereof.

FIGS. 6A and 6B are plan views illustrating a procedure for fixing a ring core according to a second embodiment.

FIGS. 7A and 7B are plan views illustrating a procedure for filling an adhesive between a ring core and a drum core according to a second embodiment.

FIG. 8 is an overall cross-sectional view of the second embodiment.

FIG. 9A is a plan view before terminal pinching according to the third embodiment, FIG. 9B is a plan view after terminal pinching,
(C) is a perspective view showing application of an adhesive.

FIG. 10 (a) is a plan view showing a process of winding around a binding portion in the third embodiment, and FIG. 10 (b) is a plan view after winding.

11A and 11B show a ring core used in a fourth embodiment, wherein FIG. 11A is a perspective view thereof, and FIG. 11B is a longitudinal sectional view.

FIG. 12 is a plan view before a ring core is fixed in a fourth embodiment, and FIG. 12B is a plan view after the ring core is fixed.

FIG. 13 is a partial sectional view of the fourth embodiment.

FIG. 14 is a perspective view of a conventional base using a lead frame.

FIG. 15 is a perspective view of a conventional base cut off from a lead frame.

FIG. 16 is a front view of a conventional small wound type surface mount electronic component.

FIG. 17 is a front view of another conventional small wound type surface mount electronic component.

FIG. 18 is a cross-sectional view of a conventional large wound type surface mount electronic component.

[Explanation of symbols]

 21 42 51 53 Wound surface mount electronic component 22 Base 22a Upper surface of base 23 Terminal 24 Drum core 25 Winding 25a Winding lead 27 Positioning protrusion 28 Engagement protrusion 34 Nipping part 35 Tether 36 Engagement hole 41 Ring core 43 Notch for escape 44 Ring projection 47 Positioning step 52 Fitting recess

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01F 41/10 H01F 15/10 D

Claims (10)

[Claims] 1. A drum-type core on which a winding is wound, a base made of an insulating resin to which the drum-type core is fixed on an upper surface, a sandwiching portion sandwiching upper and lower surfaces of the base, and the sandwiching portion being a base. And a terminal integrally formed with a binding portion around which the lead portion of the winding is wound while being positioned on the base by being sandwiched. 2. A drum-shaped core on which a winding is wound, a base made of an insulating resin to which the drum-shaped core is fixed on an upper surface, a sandwiching portion sandwiching upper and lower surfaces of the base, and the sandwiching portion being a base. A terminal integrally formed with a binding portion around which the lead portion of the winding is wound in a state of being positioned on the base by being sandwiched; and a ring shape surrounding the periphery of the drum core,
A drum core and a ring core fixed to the upper surface of the base with a gap, wherein a positioning portion for positioning the drum core and the ring core so as to maintain a predetermined gap is formed on the upper surface of the base. A wire-type surface mount electronic component, characterized in that: 3. The wire-mounted surface mount electronic component according to claim 2, wherein a ring projection protruding inward is integrally formed at an upper open end of the ring core. 4. The wire-wound surface mount electronic component according to claim 2, wherein a cutout portion for escaping the terminal is formed at a lower portion of the ring core. 5. The invention according to claim 2, wherein the positioning portion is a positioning protrusion that protrudes from an upper surface of the base between the drum core and the ring core, and positions both the drum core and the ring core. A wire-wound surface mount electronic component, characterized in that: 6. The positioning step according to claim 2, wherein the positioning section is formed on the upper surface of the base so as to be stepped higher around the drum core, and the ring core is mounted thereon. A winding type surface mount electronic component, characterized in that a fitting recess in which a positioning step is fitted is formed below the ring core. 7. The invention according to claim 1, wherein said terminal and said base are provided with engaging means for mutually engaging and fixing said terminal in a fixed position on said base. A wire-type surface mount electronic component, characterized in that: 8. A step of sandwiching the upper and lower surfaces of the base with the sandwiching portion of the terminal to position the binding portion of the terminal integrally formed with the sandwiching portion on the base; and fixing a drum core to the upper surface of the base. After that, a step of winding a winding around the drum-type core, and a step of winding the lead portion of the winding around the binding portion of the terminal, and then soldering the lead portion and the binding portion are provided. A method of manufacturing a wound type surface mount electronic component. 9. A step in which the upper and lower surfaces of the base are sandwiched between the pinching portions of the terminal to position the binding portion of the terminal integrally formed with the pinching portion on the base, and a drum core is fixed to the upper surface of the base. A step of winding a winding around a drum core; a step of winding a lead portion of the winding around the binding portion of the terminal; and then soldering the lead portion and the binding portion; Fixing the ring core to the upper surface of the base so as to have a gap with the periphery of the drum-type core in a state in which the cut-out portion for escape faces the binding portion of the terminal. Manufacturing method of winding type surface mount electronic components. 10. The invention according to claim 8, wherein the entangled portion of the terminal is raised to such an extent that it does not protrude above the lower flange portion of the drum core fixed to the base. Then, a method of manufacturing a wire-wound surface mount electronic component, comprising winding a lead portion of the wire.