JP2002252120A - Coil component and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component that is suppressed in characteristics variation by making the coating thickness of its outer jacketing section to hardly become nonuniform over the full circumference of its coil section, and to provide a method of manufacturing the component. SOLUTION: This coil component is provided with the coil section 2 having an air core 1, the outer jacketing section 3 including the coil section 2 and composed of a magnetic material, and terminals 4 which are connected to the coil section 2 and extruded from the jacketing section 3. The jacketing section 3 is formed by repress-molding two green compacts 5, by destroying the shapes of the compacts 5 so as to cover the coil section 2, and at the same time, heating the compacts 5, so that the thermosetting resin is cured completely. The green compacts 5 are obtained, by mixing a binder containing a thermosetting resin with a magnetic power in a non-heated state in which thermosetting resin is not cured completely and press-molding the mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component used for various consumer appliances and the like and a method of manufacturing the same.

[0002]

2. Description of the Related Art A conventional coil component will be described below with reference to the drawings.

FIG. 9 is a perspective view of a conventional coil part, and FIG.
Is a cross-sectional view of the coil component, and FIG. 11 is a cross-sectional view showing a part of the manufacturing process of the coil component.

Referring to FIGS. 9 to 11, a conventional coil component includes a coil part 52, an exterior part 53 made of a magnetic material including the coil part 52, and a coil part 52 connected to the coil part 52 and projecting from the exterior part 53. And the outer portion 53 is provided with a magnetic powder 55 so as to cover the coil portion 52.
Is formed by pressure molding.

When forming the exterior part 53, the upper and lower dies 5
9, the magnetic powder 55 is pressurized so as to sandwich the coil portion 52 to form a predetermined shape.

[0006]

In the above-mentioned conventional configuration,
Magnetic powder 5 so that exterior part 53 covers coil part 52.
5, the amount of the magnetic powder 55 filled between the mold 59 and the coil portion 52 is liable to fluctuate due to the movement of the mold 59 during the pressure molding.

For this reason, the coating thickness of the exterior portion 53 tends to be non-uniform over the entire periphery of the coil portion 52, so that the molding density cannot be controlled, and characteristic variations occur.
Since the magnetic powder 55 itself has fluidity as a whole, there is a problem in that the coil part 52 cannot be supported, and the coil part 52 is molded in an inclined state, thereby causing the molding of the exterior part 53 to be defective. Was.

The present invention solves the above-mentioned problems, and the coating thickness of the exterior portion is less likely to be non-uniform over the entire periphery of the coil portion, thereby suppressing variation in characteristics and accurately positioning the coil portion. To provide a coil component in which defective molding of an exterior part is prevented and a method for manufacturing the same.

[0009]

In order to achieve the above object, the present invention has the following arrangement.

[0010] The invention according to claim 1 of the present invention is characterized in that the exterior part mixes the binder containing the thermosetting resin and the magnetic powder in a non-heated state in which the thermosetting resin is not completely cured. The pressed green compact is re-pressed so as to cover the coil portion, and is heated and molded so that the thermosetting resin is completely cured. Along with providing a weak hardness portion having a hardness at which the shape of the green compact is deformed when forming, the two green compacts are formed,
The green compact is re-pressurized so that the weak hardness portion of the green compact covers the coil portion.

According to the above-described structure, the pressure molding is generally performed using a mold. However, since the compact is a solid, the amount of the compact between the mold and the coil portion is reduced. It is hard to fluctuate during re-pressing, the coating thickness of the exterior part is easy to be uniform over the entire circumference of the coil part, and it is possible to suppress variation in characteristics and to support the coil part by the green compact itself, so that the coil part Positioning becomes accurate, and defective molding of the exterior part can be prevented.

In particular, the green compact is provided with a weakly hardened portion having a hardness such that the shape of the green compact is lost when the green compact is re-pressed, and the green compact is re-formed so that the weakly hardened portion covers the coil portion. Because it is press molded, the coil part can be covered accurately, and the gap between the green compact and the coil part can be filled without gaps,
The magnetic efficiency can be improved by reducing the magnetic gap.

[0013] The second aspect of the present invention is the first aspect.
In the invention described, in particular, the shape of the green compact is deformed at the time of the re-pressing molding, and the shape of the green compact is deformed when the re-pressing is performed. A weak hardness portion having a hardness, and the exterior portion is configured such that the strong hardness portion of at least one of the green compacts supports one surface of the coil portion, and the weak hardness portion covers the other surface of the coil portion. The green compact is formed by re-press molding and heat molding so that the thermosetting resin is thermoset.

According to the above configuration, since the hardness portion of the green compact firmly supports one surface of the coil portion, the coil portion is less likely to be displaced at the time of re-pressing, so that the coil portion can be accurately positioned and the pressure portion can be accurately positioned. The weak hardness part of the powder can easily cover the other surface of the coil part while keeping its shape, and it is easy to make the coating thickness of the exterior part uniform over the entire circumference of the coil part, suppressing characteristic variations it can.

[0015] Further, since the weakly hardened portion of the deformed green compact accurately covers the coil portion, the green compact can be filled with no gap between the coil portion and the green compact. The magnetic efficiency can be improved by reducing the magnetic gap.

The invention described in claim 3 of the present invention is the same as that in claim 2
In the invention described, in particular, the shape of the green compact is an E-shape having a middle leg portion and an outer leg portion on a back portion, and the back portion is a hardened portion, and the middle leg portion and the outer portion are formed. It is a configuration in which the legs are made of a weak hardness portion.

According to the above configuration, the displacement is hardly generated with respect to the hard portion of the green compact, the other surface of the coil portion can be easily covered, and the variation in characteristics can be suppressed.

The invention according to claim 4 of the present invention is the invention according to claim 3.
In the described invention, in particular, one of the green compacts and the other green compact have a configuration in which re-press molding is performed such that the back surface of the hard part supports one surface of the coil portion.

According to the above configuration, the displacement is hardly generated with respect to the hard portion of the green compact, the other surface of the coil portion can be easily covered, and the variation in characteristics can be suppressed.

The invention according to claim 5 of the present invention is the invention according to claim 3.
In the invention described, in particular, one of the green compacts has a back surface portion of the hard part supporting one surface of the coil portion, and the other green compact has a middle leg portion inserted into a through hole of the coil portion. And pressurized again.

According to the above configuration, the displacement is hardly generated with respect to the hard portion of the green compact, the other surface of the coil portion can be easily covered, and the variation in characteristics can be suppressed.

[0022] The invention according to claim 6 of the present invention is characterized by claim 3.
In the invention described in the above, particularly, a minute uneven portion is provided at the tip of the middle leg and the outer leg of the two compacts, and the middle leg and the outer leg of the two compacts face each other. In this way, the pressure is re-pressed.

According to the above configuration, the displacement is hardly generated with respect to the hard portion of the green compact, the other surface of the coil portion can be easily covered, and variation in characteristics can be suppressed.

The invention according to claim 7 of the present invention is characterized by claim 3
In the invention described above, particularly, a configuration is provided in which a division groove for division is provided on the back surface of the green compact.

According to the above configuration, the compact is divided by the dividing grooves during the re-press molding, so that the other surface of the coil portion can be easily covered, and variation in characteristics can be suppressed.

In the invention according to claim 8 of the present invention, in particular, in the step of forming the exterior part, the binder containing the thermosetting resin and the magnetic powder are mixed in a non-heated state where the thermosetting resin is not completely cured. Forming the two green compacts by pressing and pressing, re-pressing the green compact so as to cover the coil portion, and heating the thermosetting resin to be completely cured. Forming the exterior part, and forming a weakly hardened portion of the green compact having a hardness at which the shape of the green compact is lost when the green compact is pressed again.

According to the above-mentioned method, the molding is generally carried out by using a mold for the pressure molding. However, since the compact is a solid, the amount of the compact between the mold and the coil portion is reduced. It is hard to fluctuate during re-pressing, the coating thickness of the exterior part is easy to be uniform over the entire circumference of the coil part, and it is possible to suppress variation in characteristics and to support the coil part by the green compact itself, so that the coil part Positioning becomes accurate, and a coil component in which defective molding of the exterior part is prevented can be manufactured.

In particular, since the green compact is re-pressed and molded to cover the coil portion, the coil portion can be covered accurately.
The gap between the green compact and the coil portion can be filled without any gap, and a coil component with reduced magnetic gap and improved magnetic efficiency can be manufactured.

The ninth aspect of the present invention is the eighth aspect of the present invention.
In the invention described, in particular, the shape of the green compact is deformed at the time of the re-pressing molding, and the shape of the green compact is deformed when the re-pressing is performed. A weak hardness portion having a hardness, and in the exterior portion forming step, the strong hardness portion of the green compact supports one surface of the coil portion, and the weak hardness portion covers the other surface of the coil portion. This method includes a step of re-press-molding the green compact and heat-molding the thermosetting resin so that the thermosetting resin is thermoset to form the exterior part.

According to the above method, since the strength portion of the green compact firmly supports one surface of the coil portion, displacement of the coil portion hardly occurs at the time of re-pressing, and the weak hardness portion of the green compact changes its shape. The other surface of the coil portion can be easily coated while breaking, and in particular, the coating thickness of the exterior portion can be easily made uniform over the entire periphery of the coil portion, and the variation in characteristics can be suppressed.

Further, since the weakly hardened portion of the deformed green compact accurately covers the coil portion, the green compact can be filled with no gap between the coil portion and the green compact. The magnetic efficiency can be improved by reducing the magnetic gap.

According to a tenth aspect of the present invention, in the invention of the eighth aspect, in particular, the shape of the green compact is an E-shape having a middle leg portion and an outer leg portion on a back surface thereof. This is a method in which the rear portion is a hard portion and the middle leg portion and the outer leg portion are weak portions.

According to the above method, the displacement is hardly caused with respect to the hard portion of the green compact, the other surface of the coil portion can be easily covered, and the variation in characteristics can be suppressed.

[0034]

(Embodiments) Hereinafter, in the embodiments of the present invention, all claims will be described with reference to the drawings.

FIG. 1 is a sectional view of a coil part according to an embodiment of the present invention, FIG. 2 is a perspective view of the coil part, FIG. 3 is a view showing a part of a manufacturing process of the coil part, and FIG. FIG. 5 is a perspective view of a compact of the coil component, FIG. 5 is a perspective view of a coil portion to which terminals of the coil component are connected, and FIG. 6 is a perspective view of the coil component before terminals are formed.

1 to 6, a coil part according to an embodiment of the present invention is a coil part having a height of 2 to 5 mm, a size of 10 mm square, and having an air core 1 as a through hole. 2, an exterior part 3 made of a magnetic material including the coil part 2, and an exterior part 3 connected to the coil part 2.
And a terminal 4 protruding therefrom.

The exterior part 3 is prepared by mixing a binder containing an epoxy-based or silicone-based thermosetting resin and a magnetic powder in a non-heated state in which the thermosetting resin is not completely cured, and at a rate of 1.0 to 2 parts. A green compact 5 formed by pressing at a pressure of 0.0 t / cm ² is applied to cover 3.0 to 4.0 t / cm ² so as to cover the coil portion 2.
It is formed by heating at 100 to 150 ° C. so that the thermosetting resin is completely cured while being re-pressurized and molded in cm ² .

Further, two compacts 5 are used, and the compacts 5 are re-pressed and formed with a hard portion having such a hardness that the shape of the compact 5 is not deformed when re-pressed. In this case, the compact 5 is provided with a weakly hardened portion where the shape of the compact 5 is distorted, and the compact 5 is formed into an E-shape having a middle leg portion 7 and an outer leg portion 8 on a back portion 6. 6 is a hard part, and the middle leg 7 and the outer leg 8 are weak parts. The low hardness portion and the high hardness portion are portions where the density of the green compact is reduced (low hardness portion).
And a portion where the density is increased (strong hardness portion). The weak hardness portion has a hardness such that the shape is broken by a pressure of several kg / cm ² .

Here, the hardness at which the shape of the green compact 5 is deformed means that the shape of the magnetic powder is deformed. In this case, the broken state is not included in the range of the broken hardness because the particle size of the magnetic powder is not broken.

The exterior part 3 is formed such that the hard parts of both the green compact 5 of the one green compact 5 and the other green compact 5 support one surface (upper and lower surfaces) of the coil part 2 and are weak. The green compact is re-pressurized so that the hard portion covers the other surface (side surface and air core surface) of the coil portion 2, and is heated so that the thermosetting resin is completely cured.

In the above-described method for manufacturing a coil component, an exterior part forming step of enclosing the coil part 2 with an exterior part 3 made of a magnetic material, and forming a terminal 4 connected to the coil part 2 and protruding from the exterior part 3 are formed. And a terminal forming step.

In the exterior part forming step, first, a binder containing a thermosetting resin and a magnetic powder are mixed in a non-heated state so as not to completely cure the thermosetting resin, and are molded under pressure to form two pieces. A step of forming the green compact 5 is provided.

At this time, the green compact 5 is formed into an E-shape having a middle leg portion 7 and an outer leg portion 8 on the back surface portion 6. The green compact 5 has a strong hardness portion that does not lose its shape, and the middle leg portion and the outer leg portion have weak hardness portions whose hardness is such that the shape of the green compact is lost when re-pressing.

Next, the hard portions of the two compacts 5 support one surface (upper and lower surfaces) of the coil portion 2, and the weak portions are the other surfaces (side surface and air core surface) of the coil portion 2. And the step of molding the exterior part 3 by re-pressing the green compact 5 so as to cover the thermosetting resin and heat molding so that the thermosetting resin is completely cured.

At this time, while the back part 6 of the two compacts 5 supports the coil part 2, the two dies 9 are connected to the middle leg 7 and the outer leg 8 of the weakly hardened part of the compact 5. Is pressed to cover the other surface (side surface and air core surface) of the coil portion 2 while breaking the weak hardness portion of the green compact 5.

In particular, in this case, the back surface portion 6 (strong hard portion) of the compact 5 facing the other surface (air core surface) of the coil portion 2
Is buried in the air core 1 of the coil portion 2 in a block manner, and the back surface portion 6 (the hard portion) of the compact 5 facing the terminal 4 is buried in the block toward the terminal 4. The middle leg 7 (low hardness portion) and the outer leg portion 8 (low hardness portion) of the green compact 5 are distorted and cover the other surface (the side surface and the air core surface) of the coil portion 2.

According to the above-described structure and method, pressure molding is generally performed using a mold. However, since the compact 5 is a solid, the compact is formed between the mold 9 and the coil 2. The amount of the powder 5 is less likely to fluctuate during the re-press molding, the coating thickness of the exterior part 3 tends to be uniform over the entire periphery of the coil part 2, and the inductance value and the saturation characteristics of the inductance value at the time of DC superposition and Variations in characteristics such as magnetic loss can be suppressed, and the coil part 2 can be supported by the green compact 5 itself, so that the positioning of the coil part 2 is accurate and defective molding of the exterior part 3 can be prevented.

In particular, since the green compact 5 is formed by re-pressing to cover the coil portion 2, the coil portion 2 can be coated accurately, and the gap between the green compact 5 and the coil portion 2 can be made without any gap. It can also be filled, reducing the magnetic gap and improving magnetic efficiency.

Further, since the strength portion of the green compact 5 firmly supports one surface of the coil portion 2, displacement of the coil portion 2 during re-pressing hardly occurs, and the weak strength portion of the green compact 5 The other surface of the coil portion 2 can be easily covered while losing the shape, the coating thickness of the exterior portion 3 can be easily made uniform over the entire periphery of the coil portion 2, and variation in characteristics can be suppressed.

Further, the shape of the green compact 5 is an E-shape having a middle leg 7 and an outer leg 8 on the back surface 6. Since the outer leg portion 8 is a weakly hardened portion, the misalignment with respect to the hardly hardened portion of the green compact 5 is more unlikely to occur, and the other surface of the coil portion 2 can be easily covered, and the characteristic variation can be achieved. Can be suppressed.

As described above, according to the embodiment of the present invention,
The coating thickness of the exterior part 3 is likely to be uniform over the entire periphery of the coil part 2, and variation in characteristics can be suppressed.

In the embodiment of the present invention, the compact 5
Is E-shaped, but the length of the middle leg 7 may be longer or shorter than the length of the outer leg 8 or may be any other shape without departing from the spirit of the present invention. . In particular, a T-shape in which only the middle leg 7 is formed on the back portion 6 and a U-shape in which only the outer leg 8 is formed are considered to be substantially E-shaped.

The positional relationship between the coil portion 2 and the green compact 5 is such that at least one of the green compacts 5 does not need to support one surface of the coil portion 2 even if the hard portions of the two green compacts 5 support one surface. It is sufficient that the hardened portion of the first portion supports one surface of the coil portion 2.

As another example, as shown in FIGS. 7 and 8, one of the compacts 5 has a back portion 6 of a hard portion and a coil portion 2.
And the other green compact 5 is repressurized by inserting the middle leg 7 into the air core surface 1 of the through hole of the coil portion 2, 5 and a small uneven portion 10 is provided at the tip of the middle leg 7 and the outer leg 8.
Re-pressing is performed so that the middle leg 7 and the outer leg 8 of the two compacts 5 are opposed to each other, or a dividing groove is provided on the back surface 6 of the compact 5 for re-forming. Pressure molding may be performed, and in both cases, the other surface of the coil portion 2 can be more easily covered, and variation in characteristics can be suppressed.

At this time, in the embodiment of the present invention, the hard part of the green compact 5 supports one surface of the coil portion 2 before or during the re-pressing, It is desirable that the hard part of the green compact supports one surface of the coil part 2 even after the pressing.

[0056]

As described above, according to the present invention, pressure molding is generally carried out by using a mold, but since the compact 5 is a solid, the mold and the coil part are not formed. The volume of the green compact is less likely to fluctuate during re-press molding, the coating thickness of the outer part tends to be uniform over the entire circumference of the coil part, and characteristic variations can be suppressed, and Since the coil portion can be supported, it is possible to provide a coil component in which the positioning of the coil portion is accurate and the defective molding of the exterior portion is prevented, and a method of manufacturing the same.

In particular, the green compact is provided with a weakly hardened portion having a hardness such that the shape of the green compact is lost when the green compact is re-pressed, and the green compact is re-formed so that the weakly hardened portion covers the coil portion. Because it is press molded, the coil part can be covered accurately, and the gap between the green compact and the coil part can be filled without gaps,
The magnetic gap can be reduced to improve the magnetic efficiency.

[Brief description of the drawings]

FIG. 1 is a sectional view of a coil component according to an embodiment of the present invention.

FIG. 2 is a perspective view of the coil component.

FIGS. 3A to 3E each show a part of a manufacturing process of the coil component; FIGS.

FIG. 4 is a perspective view of a compact of the coil component.

FIG. 5 is a perspective view of a coil unit to which terminals of the coil component are connected.

FIG. 6 is a perspective view of the coil component before a terminal is formed.

FIGS. 7A to 7E each show a part of a manufacturing process of another coil component;

8 (a) to 8 (d) each show a part of a manufacturing process of still another coil component.

FIG. 9 is a perspective view of a conventional coil component.

FIG. 10 is a sectional view of the coil component.

FIG. 11 is a sectional view showing a part of the manufacturing process of the coil component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air core 2 Coil part 3 Exterior part 4 Terminal 5 Green compact 6 Back part 7 Middle leg part 8 Outer leg part 9 Die 10 Fine uneven part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 105: 16 B29L 31:00 105: 20 H01F 15/02 L B29L 31:00 27/24 D (72) Inventor Hiroyuki Hamamoto 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture, Japan Matsushita Electric Industrial Co., Ltd. 1006 Kadoma Ichidai Matsushita Electric Industrial Co., Ltd. F-term (reference) 4F204 AA36 AB13 AD35 AH33 FA01 FB01 FB12 FB20 FF01 FF23 FN11 FN17 5E062 FF02 5E070 AA01 AB02 BA01 BB03 DA13

Claims (10)

[Claims] 1. An exterior part comprising: a coil part having a through hole; an exterior part made of a magnetic material including the coil part; and a terminal connected to the coil part and projecting from the exterior part. Is a method of mixing a binder containing a thermosetting resin and a magnetic powder in a non-heated state in which the thermosetting resin is not completely cured, and re-pressing a pressed green compact so as to cover the coil portion. It is molded by heating so that the thermosetting resin is completely cured with pressure molding,
The green compact is provided with a weak hardness portion having a hardness at which the shape of the green compact is deformed during re-press molding, and two compacts are formed, and the weak hardness portion of the green compact is formed. A coil component formed by re-pressing the green compact so as to cover the coil portion. 2. A green compact having a hardness portion at which the shape of the green compact is not deformed during re-pressing and a hardness at which the shape of the green compact is lost at the time of re-pressing. A weakly hardened portion, and the exterior portion is formed so that the hardly hardened portion of at least one of the green compacts supports one surface of the coil portion and the weakly hardened portion covers the other surface of the coil portion. 2. The coil component according to claim 1, wherein the powder is re-pressed and heat-molded so that the thermosetting resin is thermoset. 3. The shape of the green compact is an E-shape having a middle leg portion and an outer leg portion on a back portion, and the back portion is a hard portion, and the middle leg portion and the outer leg portion are formed. 3. The coil component according to claim 2, wherein the component is a weak hardness portion. 4. The one compact and the other compact are such that the back surface of the hard portion supports one surface of the coil portion,
4. The coil component according to claim 3, wherein the coil component is re-pressed. 5. One of the green compacts has a back surface portion of the hard part supporting one surface of the coil portion, and the other green compact has a middle leg portion inserted into a through hole of the coil portion. 4. The coil component according to claim 3, wherein the coil component is re-pressed. 6. A fine uneven portion is provided at a tip of a middle leg and an outer leg of two compacts, and the middle leg and the outer leg of the two compacts are opposed to each other. 4. The coil component according to claim 3, wherein the coil component is re-press formed. 7. The coil component according to claim 3, wherein a division groove for division is provided on the back surface of the green compact. 8. An exterior part forming step of enclosing the coil part with an exterior part made of a magnetic material, and a terminal forming step of connecting to the coil part and forming a terminal projecting from the exterior part, In the exterior part forming step, the binder containing the thermosetting resin and the magnetic powder are mixed in a non-heated state in which the thermosetting resin is not completely cured, and are pressed and molded to form two compacts. A step of re-pressing the green compact so as to cover the coil portion and heating the thermosetting resin to be completely cured to form the exterior portion; and Forming a weakly hardened portion having a hardness at which the shape of the green compact is lost during re-pressing. 9. A green compact having a hardness of such a hardness that the shape of the green compact is not deformed when the green compact is re-pressed, and a hardness of the hard portion where the shape of the green compact is broken when the green compact is re-pressed. A weakly hardened portion, wherein in the exterior portion forming step, the green compact is formed such that the hardly hardened portion of the green compact supports one surface of the coil portion, and the weakly hardened portion covers the other surface of the coil portion. 9. The method for manufacturing a coil component according to claim 8, further comprising a step of re-pressing the body and heating the thermosetting resin to completely cure the thermosetting resin to form the exterior part. 10. The shape of the green compact is an E-shape having a middle leg and an outer leg on the back surface, and the back portion is a hardened portion, and the middle leg and the outer leg are provided. The method for manufacturing a coil component according to claim 9, wherein is a weak hardness portion.