JP4436590B2 - Thin coil manufacturing method and manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thin coil used in, for example, an electric / electronic circuit and a drive circuit, a manufacturing method thereof, and a manufacturing apparatus.
[0002]
[Prior art]
In recent years, electrical and electronic circuits have been reduced in size and thickness, and electronic components have been required to be reduced in size and thickness. Also in the electronic circuit, the conventional insertion-type mounting form has shifted to the surface-mounting form, and chip components are also becoming smaller. However, it cannot be said that sufficient miniaturization has been achieved for high-capacity components such as passive components and components utilizing space characteristics such as winding coils.
[0003]
As an example of miniaturization of a coil, for example, in JP-A-5-168202, a laminated body made of a conductive foil and an insulating layer is wound a predetermined number of times to obtain a winding portion, which has a predetermined thickness. A thin coil formed by cutting is described.
As shown in the flowchart in FIG. 5, the method of manufacturing the thin coil includes a step of forming a laminated body which is a conductive foil with an insulating layer by laminating an insulating layer on the surface of the conductive foil (S051), The side edges of the laminate are temporarily fixed on the core, and an adhesive is applied to the laminate, and then the laminate is wound a predetermined number of times around the core to form a winding portion to form a coil raw material. (S052), and after the layers of the laminate are completely bonded, the step of removing the winding core and cutting the winding portion with a predetermined width (thickness) (S053), and the winding The method includes a step of etching the cut surface of the part (S054) and a step of protecting the cut surface of the winding part by coating (S055).
According to this method, a plurality of thin coils having the same resistance value can be manufactured in one process.
[0004]
[Problems to be solved by the invention]
However, the coil having the above-described configuration is a coreless coil having a hollow structure by removing the winding core after forming the winding portion. Since the coil itself is reduced in size and thickness, it is not easy to insert the core into the internal space after the winding core has been removed. Could not be used.
In addition, when wiring a coil, since it is necessary to attach at least two linear electrodes, the area occupied by the coil on the substrate can be obtained by the method when the functional configuration is performed. The area of the obtained coil becomes larger, and the size cannot be sufficiently reduced.
[0005]
Furthermore, when the coil having the above-described configuration is used, the inductance obtained with respect to the number of windings cannot be increased so much because the core does not exist. Therefore, when a relatively high inductance is desired, the number of turns must be further increased, resulting in an increase in the outer dimensions of the coil.
When manufacturing a coil having the above-described configuration, since a process that applies a shearing force such as a multi-wire saw is used for cutting, deformation such as sagging occurs on the cut surface of the conductive foil at the cut surface during cutting. Further, the possibility exists that the deformed portion may cause a short circuit between conductor foils that are adjacent or located in the vicinity of each other. In order to prevent such a short circuit, Japanese Patent Laid-Open No. 5-168202 has a serious problem that a process for etching the cut surface of the coil is required, and the manufacturing cost is increased by the amount of the process. It was.
[0006]
In the conventional method of cutting a workpiece using laser light, the depth of focus of the laser light is adjusted using a collimating lens system. When trying to cut the coil raw material using this method, the laser beam is focused on the surface portion of the coil raw material (and hence the outer peripheral portion of the winding portion), and the depth of focus of the laser light is increased from there. In the case where the focal point of the laser beam is connected near the center of the winding portion, the spot diameter of the laser beam varies. When the spot diameter of the laser beam changes, the cut surface of the winding portion has a taper in the thickness direction of the winding portion, and as a result, the side surface of the winding portion of the obtained coil becomes the core. It was also difficult to have sides that were strictly perpendicular to the longitudinal direction of the material.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a thin coil that can be obtained in a small, thin, and low cost, and that can obtain a surface-mounted form, a manufacturing method thereof, and a manufacturing apparatus. .
[0008]
[Means for Solving the Problems]
The invention of the thin coil of the present application is, in the first aspect, formed by arranging a winding part formed by winding a laminated body formed by laminating a conductor foil and an insulating layer in a spiral shape around the core material. The conductive foil is characterized in that at least the surface contacts the conductive core material.
[0009]
The thin coil invention of the present application is, in the second aspect, a laminate formed by laminating a conductor foil and an insulating layer in at least two places on the longitudinal central axis of the core material around the rod-shaped core material. It is a thin coil formed by arranging a winding part formed by winding a body in a spiral shape, and the conductive foil is characterized in that at least the surface is in contact with a conductive core material. This coil can also be referred to as a thin multipole coil.
[0010]
In the thin coil, at least one end face of the core material is provided with a first electrode protruding from the end face, and at least one end face of the winding part is covered with an insulating layer, and the winding part A second electrode that is electrically connected to the conductor foil may be provided on the outer peripheral portion of the substrate.
In the above-described thin coil, the core material may have a feature that it is formed of a conductive material selected from stainless steel, gold, silver, copper, and alloys thereof.
In the above thin coil, the core material may have a feature that it includes a main body portion made of a non-conductive material and a coating layer made of a conductive material covering the surface of the main body portion.
[0011]
In the above thin coil, the conductive foil is formed of a conductive material selected from gold, silver, copper and alloys thereof, and the insulating layer is polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polysulfone (PS), It may have a feature of being formed of a non-conductive material selected from polyimide (PI) and polyether nitrile (PEN).
The thin coil may have a disk shape as a whole.
The thin coil as described above can be applied to a mobile phone or a motor.
[0012]
In addition, the invention of the thin coil manufacturing method of the present application is a laminate comprising a conductor foil and an insulating layer electrically connected between the surface of the core material and the conductor foil on the longitudinal side surface of the rod-shaped core material. A winding part is formed by winding the body at a predetermined number of times to obtain a coil raw material, and the coil raw material has a predetermined thickness with respect to the longitudinal direction of the coil raw material. The winding portion is cut using laser light having a wavelength of 532 nm to 10.6 μm on at least two perpendicular surfaces.
The invention of the above-described method for manufacturing a thin coil can also be characterized in that the core material is also cut so as to have an end face that is flush with the cut surface of the winding portion.
[0013]
The invention relating to the thin coil manufacturing apparatus according to the present application provides a coil raw material in which a winding portion formed by winding a laminated body of a conductor foil and an insulating layer a predetermined number of times is disposed on a longitudinal side surface of a rod-shaped core material. And a laser beam source disposed on the side of the holder unit, and a condensing mirror disposed on the opposite side of the laser beam source with respect to the holder unit.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, each invention according to this application will be described with reference to the drawings.
In the drawings attached to the specification of the present application, the core material 1 and the winding portion 4 and the planar shape (hereinafter also referred to as end surface shape) of the end surface of the obtained thin coil are circular, 1 and the winding part 4 and the end surface shape of a thin coil are not restricted to this, It can be set as various shapes. Since the end face shape of the thin coil is basically determined by the end face shape of the core material 1, depending on the purpose and application of the coil, the shape of the core material 1 can be any of various shapes, for example, circular or oval. , Sectors, triangles, quadrilaterals, other polygons, or a combination of a part of these various polygonal shapes and a part of a circle or part of an ellipse or other various shapes it can.
[0015]
(Embodiment 1)
FIG. 1 schematically shows a process for manufacturing a thin coil according to the present application. In FIG. 1, 1 is a core material, 2 is a laminated body, and 3 is a joining tool. This laminated body 2 is formed by laminating an insulating layer 2i on the back surface side of the conductor foil 2c on the side in direct contact with the core material 1, and can also be expressed as a conductor foil with an insulating layer.
[0016]
The core material 1 can be formed of various conductive materials, for example, conductive materials selected from various stainless steels (SUS), gold, silver, copper, and alloys thereof. The core material 1 can also be formed by forming the main body portion using a non-conductive material and covering the surface of the main body portion with a conductive material coating layer. The coating treatment can be performed by various methods already known for forming a coating layer, such as plating, sputtering, and vapor deposition. In this example, the surface of the core material 1, particularly the surface of the side surface extending in the longitudinal direction, is plated with gold in order to ensure good conductivity. In any of the above cases, an electrode that protrudes in electrical connection with the conductive material coating layer can be provided on one end face of the core material 1.
[0017]
The conductor foil 2c can be formed of various conductive materials, but it is preferable to use a conductive material selected from gold, silver, copper, and alloys thereof. The insulating layer 2i can be formed of various non-conductive materials such as polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polysulfone (PS), polyimide (PI), polyether nitrile (PEN), etc. It is preferable to use a non-conductive material selected from:
[0018]
The joining tool 3 is a tool that can apply heat and / or ultrasonic waves to the material in contact. In FIG. 1, the laminated body 2 which is a conductor foil with an insulating layer is pressed against the longitudinal side surface of the core material 1 so that the conductor foil 2c side is in contact with the core material 1, and the insulating layer 2i of the laminated body 2 is The joining tool 3 has shown the state which is applying heat and / or an ultrasonic wave with respect to the laminated body 2 from the upper side. Therefore, in the state shown in FIG. 1, by applying heat and / or ultrasonic energy from the joining tool 3 to the laminated body 2, contact is made with the gold treated on the surface of the core material 1 and the core material 1. A metallic bond can be formed between the conductive foil 2c and the metal material (for example, copper). In this way, at least the surface side of the core material is formed of a conductive material, and the surface of the core material 1 and the conductor foil 2c are electrically connected by metal bonding (electrically). By connecting), the core material 1 and the end of the conductor foil 2c can be connected so as to have a very low ohmic resistance.
[0019]
From this state, the core material 1 is rotated in the direction of the arrow, and the laminate 2 is wound around the core material 1, whereby the winding portion 4 having an end surface as shown in FIG. 2 can be formed. When the laminated body 2 is wound around the side surface of the core material 1, as shown in the partially enlarged view of FIG. 2, when one end surface of the winding portion 4 is observed in one radial direction, the insulating layer 2 i is disposed on the outermost peripheral side. Appears, and the conductive foil 2c appears on the inside, and the winding part 4 has a configuration in which the insulating layers 2i and the conductive foil 2c appear alternately inward in the radial direction.
[0020]
Thus, the coil raw material is formed by forming the winding part 4 having a predetermined number of turns around the core material 1. The coil raw material obtained in this way is cut by two surfaces perpendicular to the longitudinal direction so as to have a predetermined thickness (for example, thickness D1 shown in FIG. 6) in the longitudinal direction of the core material 1. Thus, a thin coil according to the present invention as shown in a perspective view in FIG. 6 can be obtained.
[0021]
As described above, the thin coil according to the present invention has the core material 1 inside the winding part 4, and therefore is different from a hollow coil (coreless coil) in which a cavity exists in the inner part of the winding part 4. In addition, the entire volume occupied by the coil can be used sufficiently and effectively.
Further, in the process of manufacturing the winding part 4, it is possible to manufacture the coil while measuring the inductance of the coil in real time. Therefore, by manufacturing while measuring the inductance of the coil, it is possible to accurately recognize when the desired inductance is achieved, and by linking the recognized time and the coil manufacturing process, the necessary windings can be obtained. A coil having the number of times (and hence inductance) can be obtained accurately, and a small coil with high accuracy can be manufactured.
[0022]
Therefore, according to the present invention, each material of the core material 1, the conductor foil 2c, and the insulating layer 2i, and the material, dimensions, shape, etc. as a thin coil are appropriately selected, and the range of the order of 1 nH to 1000 μH. A thin coil having various inductances can be obtained.
The term “thin” for the coil of the present invention means that the shape of the coil is thin, that is, when attention is paid to the three-dimensional dimension of the coil, the dimension is smaller than the dimension in one direction (passing length L). It means that the dimension in the other direction (thickness D) is relatively small. For example, the coil shown in FIG. 6 is a thin coil having a thickness D that is relatively smaller than the passing length L.
[0023]
In the present embodiment, the surface of the core material 1 is gold-plated, but a copper bar may be used as the material of the core material 1 and the surface thereof may be solder-plated.
Moreover, the joining tool 3 does not necessarily need to be a tool to which an ultrasonic wave can be applied. For joining the core material 1 and the conductor foil 2c, welding by metal brazing using heat can be employed.
[0024]
(Embodiment 2)
In FIG. 3, a thin coil having a predetermined thickness (for example, thickness W1 shown in FIG. 6) is cut out from a coil raw material in which winding portions 4 having a predetermined number of turns are arranged on the side surface in the longitudinal direction of the core material 1 ( It is a figure which illustrates typically the method of a process to cut | disconnect and the apparatus used for the process.
In the apparatus shown in FIG. 3, 5 is a reflecting mirror, 6 is a laser light source, and 7 is a fender. A holder portion (not shown) is provided at the central portion of the apparatus shown in FIG. 3, and the long coil raw material formed as described above is attached to the holder portion. In FIG. 3, the coil raw material is shown as a winding part 4.
[0025]
A laser light source 6 capable of emitting laser light used for cutting the coil raw material is disposed on one side of the holder portion, and a light collecting light is disposed on the side opposite to the laser light source 6 with the holder portion interposed therebetween. A reflection mirror 5 having a function as a mirror is arranged. Further, between the holder part and the laser light source 6, a fender plate 7 is provided for blocking the laser light so that the coil raw material attached to the holder part is not directly irradiated with the laser light.
When laser light having a predetermined wavelength is emitted from the laser light source 6 in the direction indicated by the white arrow in FIG. 3, the laser light is blocked in the region where the fender plate 7 is present. Only the laser light strikes the reflection mirror 5.
[0026]
On the other hand, the reflection mirror 5 is curved so as to be focused at a predetermined focal length after the laser light from the laser light source 6 hits and reflects. Note that one or more piezoelectric elements 8 are installed on the back side of the reflecting mirror 5 at positions according to the object of the present invention, and the piezoelectric elements 8 are connected to a control mechanism (not shown). Therefore, the curvature of the reflecting mirror 5 can be adjusted by controlling the control mechanism, and as a result, the focal length of the laser light reflected by the reflecting mirror 5 can be finely adjusted.
[0027]
For example, the reflecting mirror 5 can be configured by laminating a support such as beryllium copper on the back side of a metal foil having one surface polished to have a mirror surface, such as an aluminum foil, and the back of the support. On the side, the piezoelectric element 8 such as PZT can be attached at an appropriate position and number. By applying a voltage to the piezoelectric element 8, the shape of the reflection mirror 5 can be deformed, and the depth of focus at which the laser light reflected by the reflection mirror 5 is focused can be controlled. In this case, conditions such as the structure of the reflection mirror 5, the type and mounting position of the piezoelectric element 8 disposed therein, and the level of the voltage applied to the piezoelectric element 8 can be set by a person skilled in the art through experiments or the like according to the purpose. it can. In addition, when the insulating layer in the laminated body 2 has sufficient resistance to the heat of laser processing, the fender plate 7 can be omitted.
[0028]
A process of controlling the depth of focus that the laser beam reflected by the reflecting mirror 5 is connected to the coil raw material, and an operation of rotating the holder portion holding the coil raw material around the central axis in the longitudinal direction of the core material 1 By associating with each other, only the winding part 4 can be cut without cutting the core material 1. By this process, only the winding part 4 can be divided into two or more parts in the longitudinal direction of the core material 1 without cutting the core material 1, for example, a thin shape having a mutual inductance action as shown in FIG. A coil can be formed. As a matter of course, a thin coil can be formed by cutting the core material 1 in the same plane as the winding part 4.
[0029]
Although it depends on the size of the spot width of the laser beam, the relative position in the longitudinal direction of the core material 1 between the focal position of the laser beam reflected by the reflecting mirror 5 and the coil raw material during this processing. For example, a thin coil (quadrupole coil) having a mutual inductance action as shown in FIG. 7 is used for cutting the two winding parts 4 ′ and 4 ″ by changing (displacement) the relationship by a minute distance. The respective thicknesses D2 and D3 and the distance G between the two winding portions 4 ′ and 4 ″ can be adjusted with an accuracy of μm. As an example, if the beam width of the laser light emitted from the laser light source 6 is 10 to 100 μm and the depth of focus of the reflection mirror 5 can be adjusted in the range of 10 μm to 10 mm, the coil raw material having a diameter of 1 μm to 10 mm is cut. be able to.
[0030]
In addition, regarding the wavelength of the laser beam, it is suitable for cutting copper when using a laser light source having a wavelength of 532 nm, and suitable for cutting aluminum when using a laser light source having a wavelength of 10.6 μm. By using a laser light source with a wavelength of 532 nm to 10.6 μm, coil raw materials using various materials can be cut.
[0031]
Since the cutting is performed by focusing the laser beam on the workpiece using the reflection mirror having the function as a condensing mirror in this way, the end surface of the obtained thin coil (the surface cut by the laser beam) ) Can be prevented, and a thin coil having a substantially flat end face can be obtained, and the shape of such a cut surface can be stably secured.
Further, when the collimating lens system is used, it is necessary to physically move the collimating lens system, and thus there is a restriction on the depth direction to be processed. According to the method of the present invention, the piezoelectric element It is possible to freely adjust the depth of focus in a wider range by appropriately arranging and controlling the reflecting mirror and operating the reflecting mirror, and it is possible to remove the conventional restriction on the depth direction.
[0032]
(Embodiment 3)
Next, an example of mounting the thin coil of the present invention will be described with reference to FIG. In FIG. 4, 9 is a substrate, 11 is a first electrode, 12 is a second electrode, 13 is a bonding material, 14 is an insulating layer, and 10 is a third electrode provided on the substrate side. In this embodiment, a central electrode is assumed as the first electrode, and an outer peripheral electrode of the coil is assumed as the second electrode.
[0033]
The coil shown in FIG. 4 is the thin coil of the present invention formed by arranging the winding portion 4 around the core material 1 described in the first embodiment, and is directed downward to the lower side of the core material 1. The center electrode 11 is provided by arranging the projecting electrode, the lower surface of the winding part 4 is covered with the insulating layer 14, and the outer peripheral side electrode 12 is provided on the outer peripheral side of the winding part 4. Is. On the outer peripheral side of the winding part 4, the insulating layer 2i is peeled to expose the conductor foil 2c, and the outer peripheral electrode 12 is connected to the exposed conductor foil 2c.
[0034]
The lower surface of the coil is formed, for example, by forming the central electrode 11 on the core material 1 and then forming the insulating layer 14 so as to cover at least one side surface of the winding portion 4. Processing is performed so as to be exposed below the insulating layer 14. The connection between the core material 1 and the central electrode 11 and the connection between the conductor foil 2c and the outer peripheral electrode 12 on the outer peripheral side of the winding part 4 are performed by means such as metal spraying. Furthermore, the electrodes 10a and 10c on the substrate 9 side are electrically connected to the outer peripheral electrode 12 by a bonding material 13 (for example, solder), and the electrode 10b on the substrate 9 side is in direct contact with the center electrode 11 to be electrically connected. Connected.
In this way, the thin coil of the present invention attached to the substrate 9 is made to function as a coil by allowing signals to be input and output between the center electrode 11 and the outer electrode 12. It becomes possible.
[0035]
【The invention's effect】
As described above, according to the thin coil of the present invention, since the core can be used for inductance, the entire volume of the coil can be used effectively. Therefore, compared to a coil without a core and having a similar winding part, the thin coil of the present application can achieve an equivalent inductance even with a relatively small number of turns, and thus the outer dimensions of the coil. (Volume) can be further reduced.
In the thin coil of the present invention, by making at least the surface of the core material conductive, the core material and the end portion of the conductor foil can be electrically joined so as to have a very low ohmic resistance.
[0036]
In the thin coil of the present invention, the center electrode is directly provided on one end face of the core material, and the outer peripheral electrode is directly provided on the outer peripheral portion of the winding portion, whereby the first and last coils for connecting the coil to the substrate are provided. Since it is not necessary to use electrodes in the form of lead wires for wiring processing, the area occupied by the coil on the substrate when functionally configured can be made smaller than that of conventional types of coils, and therefore equivalent. When the coils exhibiting the above characteristics are compared, the occupied area of the coil on the substrate can be further reduced, and the substrate can be further miniaturized.
Furthermore, according to the thin coil manufacturing method of the present invention, the laser beam is used without applying a shearing force for cutting the winding part and the core, so that the cutting is performed by deforming the cut surface of the conductor at the time of cutting. Since it is possible to eliminate the possibility of causing a short circuit in the subsequent winding portion and to eliminate the necessity of performing processing such as etching on the side surface of the coil which is a cut surface, the manufacturing cost can be reduced.
[0037]
According to the coil of the present invention, the number of turns of the laminate when forming the winding part, the thickness D of the winding part, and in the case of a quadrupole coil, the gap G between the two winding parts is adjusted to reduce the thickness. However, it is possible to form a coil having an inductance having a desired magnitude, and in some cases, a thin coil having a mutual inductance action.
The thin coil of the present invention can have more excellent characteristics such as inductance when having the same volume or size as compared with the conventional coil, or more when having the same characteristic. Since it can have a small volume and / or size, it can contribute to miniaturization of a mobile phone or a motor by using it for a mobile phone or a motor that is targeted for further miniaturization.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically illustrating a process for manufacturing a thin coil of the present invention.
FIG. 2 is a side view of the thin coil of the present invention.
FIG. 3 is a schematic view for explaining a method for producing the thin coil of the present invention.
FIG. 4 is a cross-sectional view illustrating a thin coil of the present invention mounted on a substrate.
FIG. 5 is a flowchart for explaining the outline of a manufacturing process of a conventional thin coil.
FIG. 6 is a perspective view schematically showing a thin coil of the present invention.
FIG. 7 is a perspective view schematically showing a thin coil having a mutual inductance action according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Core material, 2 ... Laminated body, 2c ... Conductive foil, 2i ... Insulating layer, 3 ... Joining tool, 4 ... Winding part, 5 ... Reflection mirror, DESCRIPTION OF SYMBOLS 6 ... Laser light source, 7 ... Fender plate, 8 ... Piezoelectric element, 9 ... Substrate, 10a, 10b, 10c ... Electrode, 11 ... First electrode, 12 ... 2nd electrode, 13 ... bonding material, 14 ... insulating layer.

Claims (5)

The longitudinal side of the rod-shaped core material, and electrical connection between the surface and the conductor foil of the core material, a winding portion is formed by winding a laminate comprising the conductor foil and insulating layer Obtaining the coil raw material, and cutting the coil raw material using laser light on at least two surfaces perpendicular to the longitudinal direction so as to have a predetermined thickness in the longitudinal direction. Comprising
A method of manufacturing a thin coil, wherein a coil having a desired inductance is manufactured while measuring the inductance of the coil in real time in a winding step. The longitudinal side of the rod-shaped core material, and electrical connection between the surface and the conductor foil of the core material, a winding portion is formed by winding a laminate comprising the conductor foil and insulating layer Obtaining the coil raw material, and cutting the coil raw material using laser light on at least two surfaces perpendicular to the longitudinal direction so as to have a predetermined thickness in the longitudinal direction. Comprising
In combination with a laser beam, using a curved condenser mirror,
It said current by adjusting the curvature of the optical mirror, the manufacturing method of the thin type coil you characterized and Turkey to adjust the focal length of the laser beam by a piezoelectric element installed in the condensing mirror. The method of manufacturing a thin coil according to claim 2, wherein in the winding step, the coil is wound while measuring the inductance of the coil in real time. A holder part for holding a coil raw material in which a winding part formed by winding a laminated body of a conductor foil and an insulating layer at a predetermined number of times on a longitudinal side surface of a rod-shaped core material is disposed;
A laser light source disposed on a side of the holder part;
A condensing mirror disposed on the opposite side of the laser light source with respect to the holder part;
Means for measuring the inductance of the coil,
The apparatus for manufacturing a thin coil for carrying out the method according to claim 1, wherein the coil inductance measurement and the winding step can be linked to each other. A holder part for holding a coil raw material in which a winding part formed by winding a laminated body of a conductor foil and an insulating layer at a predetermined number of times on a longitudinal side surface of a rod-shaped core material is disposed;
A laser light source disposed on a side of the holder part;
A condensing mirror disposed on the opposite side of the laser light source with respect to the holder part;
Means for measuring the inductance of the coil,
Collecting the light mirror apparatus for manufacturing a thin coil for carrying out the method according to claim 2 or 3, characterized in that the piezoelectric element for adjusting the curvature of the mirror said condensing is installed.

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