JP2001267138A - Inductance element - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a winding-type inductance element capable of improving the joining strength of a lead portion of a winding. SOLUTION: Terminal parts 14 and 15 are provided at both ends of a base 7, a winding part 8 is provided at a center part of the base 7, a winding 13 is wound around the winding part 8, and both ends of the winding 13 are connected. Terminal 1
4, an inductance element provided with a protective material 16 covering the winding 13 and provided with tapered portions 11 and 12 at both ends of the base 7, and a taper 11a provided between the flange portion and the taper 11b. The taper 11a has a curved surface or a concave shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductance element used for a mobile communication device, a power supply, and other electronic devices.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view showing a conventional inductance element (Japanese Utility Model Laid-Open No. 61-144616). In FIG. 7, reference numeral 1 denotes a base, and base 1 has flanges 2 and 3 at both ends.
Are provided, and a winding portion 4 is formed between the flange portion 2 and the flange portion 3. The flanges 2 and 3 are provided with grooves 5 respectively. Reference numeral 6 denotes a winding wound around the base 1, and the ends of the winding 6 are respectively held in the grooves 5.
With such a configuration, when mounting an inductance element on a circuit board or the like, there is no directionality, the mountability is improved, and the productivity of the circuit board is improved. In addition, since the winding does not protrude from the flange portion serving as the joining portion, the mountability can be improved.

Another conventional technique is disclosed in, for example,
JP-A-124748, JP-A-8-124747, JP-A-8-213248 and Japanese Utility Model Laid-Open No. 3-1.
No. 510, JP-A-9-306744, and the like.

Further, as disclosed in Japanese Patent Application Laid-Open No. 10-172832, a configuration is known in which a step-shaped tapered portion is provided between a winding portion for winding a winding and a flange portion serving as a terminal portion at both ends. ing.

[0005]

However, in the case of a single-stage wound inductance element, the lead portion of the winding is joined to the external electrode and is held only by a relatively thin protective material. There was a problem that the strength was weak and the winding was easily detached.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a winding-type inductance element capable of improving the joining strength of a lead portion of a winding.

[0007]

According to the present invention, a first and a second taper are provided at both ends of a base, and a first taper is disposed between the second taper and a flange. The taper has a curved surface and is formed in a circular shape, and the first taper has a configuration in which only the lead portion of the winding is opposed to the first taper. Further, instead of the first taper, a concave portion is provided. Was formed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 includes a base having flanges at both ends of a winding portion, terminal electrodes provided at both ends of the base, and a winding wound around the base. And a protective material covering the winding, the winding having a winding part wound around the base, and leading parts provided at both ends of the winding part, wherein the leading part is An inductance element joined to a terminal electrode, wherein first and second ends are provided at both ends of the base, respectively.
The first taper is disposed between the second taper and the flange portion, and the first taper is formed in a curved shape and in a circular shape, and the first taper is formed. Since only the lead portion of the winding faces the taper, the thickness of the protective material near the flange does not decrease, and the base of the joint between the lead and the terminal electrode is protected. Therefore, the holding strength of the drawer can be improved.

According to a second aspect of the present invention, there is provided a base having flanges at both ends of a winding portion, terminal electrodes provided at both ends of the base, a winding wound around the base, And a winding member wound around the base, and leading portions provided at both ends of the winding portion, and joining the leading portion to the terminal electrode. In the inductance element, a taper is provided at both ends of the base, and a circular concave portion is provided between the taper and the flange portion, and only the lead portion of the winding faces the concave portion. As a result, the thickness of the protective material in the vicinity of the flange does not become thinner, and the base of the joint of the lead portion and the terminal electrode can be securely held by the protective material, thereby improving the holding strength of the drawer. Can be done.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a perspective view showing an inductance element according to an embodiment of the present invention.

In FIG. 1, reference numeral 7 denotes a substrate, and the substrate 7 is made of a nonmagnetic material such as alumina or ferrite (specifically, Ni-M
Magnetic materials such as n-based ferrite and Ni-Zn-based ferrite are used. When a nonmagnetic material such as alumina is used as a constituent material of the base 7, the corresponding frequency is 10
The frequency is preferably 0 MHz or more. In particular, when the above-mentioned alumina or a material containing alumina is used as the nonmagnetic material, it is very advantageous in terms of characteristics and cost. Also, the base 7
When a magnetic material such as ferrite is used as a constituent material of (1), it is advantageous in characteristics, workability and cost.

FIGS. 2 and 3 are a perspective view and a side view showing only the base 7 of the inductance element according to the embodiment of the present invention. As shown in FIGS. 2 and 3, the base 7 is composed of a winding portion 8 for winding a winding described later and flange portions 9 and 10 provided at both ends of the winding portion 8, respectively. The cross-sectional shapes of the winding portion 8 and the flange portions 9 and 10 are substantially rectangular parallelepipeds.
Further, the winding portion 8 is stepped down from the flange portions 9 and 10, and the diameter of the winding portion 8 is smaller than the diameter of the flange portions 9 and 10. Since a winding to be described later is wound on the winding portion 8, it is preferable that the corners are chamfered or tapered for the purpose of preventing a coating or the like of the winding from being damaged and short circuiting.

Further, for example, by providing a tapered portion 11 at the boundary between the flange portion 10 and the winding portion 8, it is possible to easily wind the winding and to prevent the wound coating from being damaged. . Similarly, a tapered portion 12 was provided at the boundary between the flange portion 9 and the winding portion 8.

Reference numeral 13 denotes a winding wound around the base 7 and the winding 1
3 is wound on the winding portion 8, and the winding 13 is wound with a gap or wound closely. By winding the winding 13 on the winding portion 8 with a gap provided therebetween, it is possible to prevent the Q value from deteriorating. By winding the winding 13 in close contact, the number of turns can be increased and the inductance can be increased. The winding 13 is preferably formed of at least one of conductive materials such as silver, silver alloy, copper, copper alloy, gold, gold alloy, aluminum, and aluminum alloy. In consideration of ease of handling and the like, it is preferable to use copper or a copper alloy.

Reference numerals 14 and 15 denote terminal portions provided on the flange portions 9 and 10, respectively. The terminal portions 14 and 15 are composed of terminal electrodes and a bonding layer.

As shown in FIG. 4, a terminal electrode is composed of a base film 100 made of a conductive material on a base 7 and a base film 100.
Conductive film 101a formed of a conductive material formed on
And a conductive film 101b stacked on the conductive film 101a. In this case, in particular, the base film 100
Is formed on the base 7 by electroless plating, or a conductive paste is applied on the base 7 and formed by baking, thereby forming the base 7 made of a ceramic (alumina, ferrite, or the like) which is difficult to perform electrolytic plating. The base film 100 can be easily formed on the base film 100. By forming the conductive film 101a on the base film 100 by electrolytic plating, a terminal electrode having a large thickness can be formed in a short time. .

Further, the crushed end of the winding 13 is sandwiched between the conductive films 101a and 101b. At this time, at least the conductive film 101b is a material that does not melt at 260 ° C. (preferably 300 ° C.) (having a melting point of 260 ° C.).
Above). That is, the conductive film 101b is preferably formed of a metal material having a melting point of 260 ° C. or higher, preferably 300 ° C. or higher. With such a configuration, the ends of the winding 13 are connected to the conductive film 101a and the conductive film 101b.
, The joining strength is greatly increased, and the probability of the winding 13 falling off from the terminal portions 14 and 15 is extremely reduced. Note that in this embodiment, both the conductive films 101a and 101b are
It was composed of a material that did not melt at 60 ° C.

Further, by forming the conductive film 101b from a material that does not melt at 260 ° C. (preferably 300 ° C.), the conductive film 101b is usually heated at a temperature at which the bonding material used to bond electronic parts and the like to a circuit board or the like melts. Is configured to be difficult to melt, so even if it is heat-treated by reflow or the like,
The winding 13 does not come off.

In this embodiment, the terminal electrode is composed of three layers (the base film 100, the conductive film 101a, and the conductive film 101b), but may be two layers or four or more layers. 2 terminal electrodes
In the case of using a single-layer structure, for example, the base film 100 and the conductive film 101a are formed of one conductive film, and the conductive film 101b is provided on the conductive film.
00 is unnecessary, the conductive film 101a is directly formed on the base 7.
And the conductive film 101b are sequentially stacked. When it is desired that the terminal electrode itself has weather resistance, when the substrate 7 is protected, or when the adhesion strength between the terminal electrode and the substrate 7 is improved, a multilayer film of three or more layers is used. preferable.

Underlayer 100, conductive film 101a, conductive film 1
As the constituent material of 01b, a conductive metal material such as copper, silver, and gold, a conductive alloy material such as a copper alloy, a silver alloy, and a gold alloy, and a material obtained by adding other elements to the conductive material are used. . In particular, forming silver or a silver alloy on the base film 100 by baking and forming the conductive film 101a on the base film 100 by electrolytic plating of copper or a copper alloy is extremely difficult in terms of productivity and cost. Advantageously, the bonding strength between the base 7 and the terminal electrode can be increased.

The conductive film 101a is made of silver, copper, silver alloy,
The conductive film 101b is preferably made of at least one of copper alloy, solder, tin, nickel, nickel alloy, gold, and gold alloy. The conductive film 101b is made of silver, copper, silver alloy, copper alloy, nickel, nickel alloy, gold, and gold. Alloy, tin-silver alloy, tin-bismuth alloy,
It is preferable to use at least one of tin-silver-bismuth. The conductive film 101b is made of at least one of a tin-silver alloy, a tin-bismuth alloy, and a tin-silver-bismuth alloy. We can supply very friendly electronic components.

Further, as a particularly preferred embodiment,
As the base film 100, silver or a silver alloy is formed by baking or the like, and a conductive film 101a made of silver or a silver alloy is formed thereon by a plating method such as electrolytic plating.
Next, there is a configuration in which the winding 13 is joined to the conductive film 101a by thermocompression bonding or ultrasonic welding, and thereafter, the conductive film 101b is formed of copper or a copper alloy having a melting point of 260 ° C. or higher.

In this embodiment, the thickness of the base film 100 is 2 μm to 30 μm (more preferably, 2 μm to 30 μm).
10 μm), and 10 μm to 30 μm (more preferably 18 μm to 2 μm) for the conductive film 101 a.
2 μm), and 3 μm to 100 μm (more preferably 20 μm to 3 μm) for the conductive film 101 b.
0 μm).

A bonding layer is formed on the terminal electrode. This bonding layer becomes unnecessary when solder or the like for electrically connecting to the element is attached to a wiring pattern or the like. However, in general, to increase the bonding strength with the circuit board,
It is preferable to provide a bonding layer.

The bonding layer is composed of a corrosion-resistant layer 102 and a bonding surface layer 103. The bonding surface layer 103 is required at least as the bonding layer, and the corrosion-resistant layer 102 is provided as necessary and sometimes. Ni, T as the corrosion-resistant layer 102
A corrosion-resistant metal such as i or palladium or an alloy thereof is formed by a plating method or the like. This corrosion resistant layer 10
By providing 2, it is possible to dramatically improve the corrosion resistance of the terminal electrode. On the corrosion-resistant layer 102, a bonding surface layer 103 made of a conductive bonding material such as solder and formed by plating or the like is provided.

Reference numeral 16 denotes a protective material provided so as to cover almost all of the windings 13 except for the ends as shown in FIG. 5, and the protective material 16 is made of a weather-resistant material such as epoxy resin. ing. In FIG. 1, the protective material 16 is omitted, and in FIG.
Although not provided, the coil 6 is substantially provided on the winding portion 8 in a circling manner, and is configured to cover except for both end portions of the winding 13.

A resist can be used as a constituent material of the protective material 16. By using the resist, the protective material 16 can be easily formed, and the productivity is improved.

As described above, the protective material 16 is
Is provided, the element is easily sucked by the nozzle of the mounting machine, and the winding 13 is not deformed or sometimes cut by the nozzle or the like. In addition, by using an insulating material as the protective material 16, the winding 13
A reliable insulation between them can be performed.

In addition, by using a resin material having a smooth surface as the protective material 16, the suction characteristics at the nozzle can be further improved, and mounting errors and the like can be suppressed.
As described above, by providing a structure in which the protective member 16 is provided in a winding-type inductance element which has been unsuitable as a mounting component in the related art, the mountability can be dramatically improved.

The protective member 16 may have a configuration in which a tube-shaped body made of a heat-shrinkable resin material is inserted into the base 7. With such a configuration, the dimensional accuracy can be greatly improved, the winding can be reliably protected, the process can be simplified, and the occurrence of defective products can be suppressed. As a specific method, first, a tube-shaped body having a diameter larger than that of the base 7 (the cross section is circular, square,
(An elliptical shape or the like) is made of a heat-shrinkable material, and the tubular body is inserted into the base 7 and heat-treated to shrink the tubular body, and the tubular body is securely provided on the base 7.

Next, the tapered portions 11 and 12 will be described with the tapered portion 11 as a representative.

The taper portion 11 has a taper 11 on the flange side.
a and a taper 11b. The taper 11a is provided on the side of the flange portion, is provided in a circular shape on the base 7, and has a configuration having a curved surface (the cross section is curved).
Further, it is preferable that the cross-sectional shape of the taper 11a be a convex shape facing the base 7 side. With such a shape, only the leading portion 13b provided at the end of the winding portion 13a of the winding 13 faces the taper 11a, and the leading portion 13b
Can be provided with a gap between the lead portion 13b and the bottom surface of the taper 11a. Therefore, by providing the protective material 16, the taper 11a is formed into a concave shape or a shape similar thereto,
More protective material 16 can be stored in the taper 11a, and as described above, the drawer 13b and the taper 1a
Since the protective material can be provided also in the gap between the bottom surface 1a and the bottom surface of the lead portion 13a, it is possible to substantially cover the periphery of the base of the joining portion with the terminal portion 14 in the lead portion 13b with the protective material 16. Therefore, the holding strength of the drawer 13b can be improved.

Further, by providing the taper 11b which changes substantially linearly or in a curve continuously to the taper 11a, the surface of the protective material 16 can be made flat and the adsorbability can be improved. .

In this embodiment, the taper 11a
Is provided continuously to the flange portion 9, but may be provided near the flange portion 9 via a taper of another shape.
Although only one is provided, a plurality of tapers may be provided.

FIG. 6 shows a specific example. As shown in FIG. 6A, the taper 11a has a semi-recessed cross section,
As shown in FIG. 6B, a configuration in which the taper 11a has a concave cross section is conceivable. In particular, by adopting the structure shown in FIG. The holding strength of the portion 13b can be increased. As a modification of the structure shown in FIG.
As shown in FIG. 6C and FIG. 6D, a concave portion having a triangular cross section or a rectangular cross section is formed. 6 (c) and FIG. 6 (d), the bottom of the taper 11a has a shape recessed from both ends of the taper 11a. In this way, the taper 11a
A similar effect can be obtained by forming a circular recess.

Since the tapered portion 12 has the same structure as described above, the description is omitted.

[0038]

According to the present invention, first ends are provided on both ends of the base.
And a second taper is provided, a first taper is arranged between the second taper and the flange portion, and the first taper is formed in a curved surface shape and in a circular shape. Has a configuration in which only the drawer part is facing in the winding,
Furthermore, by forming the concave portion instead of the first taper, the thickness of the protective material near the flange portion is not reduced, and the base portion of the connecting portion between the lead portion and the terminal electrode is formed of the protective material. Since it can be held securely, the holding strength of the drawer can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an inductance element according to an embodiment of the present invention.

FIG. 2 is a perspective view showing only a base of the inductance element according to the embodiment of the present invention;

FIG. 3 is a side view showing only the base of the inductance element according to the embodiment of the present invention;

FIG. 4 is a partial cross-sectional view showing an inductance element according to one embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing an inductance element according to one embodiment of the present invention.

FIG. 6 is a partial cross-sectional view showing an inductance element according to one embodiment of the present invention.

FIG. 7 is a perspective view showing a conventional inductance element.

[Explanation of symbols]

 Reference Signs List 7 base material 8 winding part 9,10 flange part 11,12 taper part 11a, 11b taper 13 winding 14,15 terminal part 16 protective material 100 base film 101a conductive film 101b conductive film 102 corrosion resistant layer 103 bonding surface layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Mitsuo Kamimei 1006 Kadoma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. F term (reference) 5E043 AA01 AB01 FA07 5E070 AA01 AB10 BA03 CB17 CB18

Claims (2)

[Claims] 1. A base having flanges at both ends of a winding part, terminal electrodes provided at both ends of the base, a winding wound on the base, and a protective material covering the winding. An inductance element having a winding portion wound around the base and leading portions provided at both ends of the winding portion, wherein the leading portion is joined to the terminal electrode. Providing first and second tapers at both ends of the base, respectively, disposing the first taper between the second taper and the flange portion,
An inductance element, wherein the first taper has a curved shape and is formed in a circular shape, and only a lead portion of a winding faces the first taper. 2. A base having flanges at both ends of a winding part, terminal electrodes provided at both ends of the base, a winding wound around the base, and a protective material covering the winding. An inductance element having a winding portion wound around the base and leading portions provided at both ends of the winding portion, wherein the leading portion is joined to the terminal electrode. The taper is provided at both ends of the base, and a circular concave portion is provided between the taper and the flange portion, and furthermore, only the drawing portion is opposed to the concave portion in the winding. Inductance element.