Patent Description:
The present invention relates to a manufacturing method of a coil component and a manufacturing apparatus of a coil component.

There have been proposed various kinds of coil components each of which includes a magnetic core and a winding-wire coil.

Among such coil components, there exists a lamp ballast described in <CIT>, in which a coil is wound on a two-part iron core, the coil-wound core is placed in a case and a mixure of polyester resin and coarse quartz particles is filled part-way up the case, then cured, so as to cover a gap between the two parts of the iron core. Before curing, the pressure in the case is reduced.

Among such coil components, there also exists a component in which a coil formed by winding a rectangular wire or the like is attaching onto a magnetic-body core formed by a magnetic-body and in which there is further provided a magnetic cover portion which covers those members (see Patent Document <NUM>: <CIT>). This magnetic cover portion is formed by filling the inside of a mold with an admixture which is obtained by mixing metal-made magnetic powders and a resin by using an injection molding technique in a molten state, and then, by employing a mold-forming process using a magnetic material.

<CIT> does disclose a manufacturing method of a coil component for forming a coil-assembly body in which a coil is mounted on a magnetic-body core.

Meanwhile, it is required for the constitution as mentioned above that filling defects of the admixture would not occur at the periphery or the like of the coil on an occasion of mass-producing the coil components. For that reason, it is conceivable to pressurize the admixture. However, the admixture mentioned above has a comparatively high viscosity and even if the admixture thereof is pressurized, there may be a space which is not sufficiently filled with the admixture (filling defect) in the mold. The filling defect of the admixture becomes one reason of a fluctuation which occurs in the quality of the coil component.

The present invention was invented in view of such a problem and is addressed to providing a manufacturing method of a coil component and a manufacturing apparatus of a coil component in which it is possible to decrease the filling defect of the admixture.

The present invention provides a manufacturing method of a coil component as recited in appended claim <NUM>.

The present invention further provides a manufacturing apparatus of a coil component as recited in appended claim <NUM>.

According to the present invention, it becomes possible to provide a manufacturing method of a coil component and a manufacturing apparatus of a coil component, in which it is possible to decrease filling defects of the admixture.

Hereinafter, there will be explained a manufacturing method and a manufacturing apparatus according to the present invention for manufacturing a coil component <NUM>. In the following explanation, there will be used the XYZ orthogonal coordinate system if it is necessary. In the XYZ orthogonal coordinate system, "X direction" indicates a direction in which terminals 43a, 43b are aligned in <FIG> in which "X1 side" indicates the right front in which terminals 43a, 43b are aligned in <FIG> in which "X1 side" indicates the right front in <FIG> and "X2 side" indicates the left rear side which is opposite thereto. In addition, "Y direction" indicates a direction in which the terminals 43a, 43b extend on the lower bottom surface 31C in which "Y1 side" indicates the right rear side in <FIG> and "Y2 side" indicates the left front side which is opposite thereto. In addition, "Z direction" indicates the axis direction of a pillar-shaped core portion <NUM> in which "Z1 side" indicates the upper side thereof and "Z2 side" indicates the lower side thereof.

First, prior to the explanation of the manufacturing method and the manufacturing apparatus of the first embodiment of the invention, there will be explained the coil component <NUM> which is manufactured by the manufacturing method and the manufacturing apparatus of the first embodiment of the invention.

<FIG> is a perspective view transparently showing an internal constitution of a coil component <NUM>. <FIG> is a cross-sectional view along an arrow B-B shown in <FIG>. In <FIG>, there is shown a cross-section of only the magnetic cover portion <NUM>. And a coil-assembly body <NUM> is shown by a side view thereof.

The coil component <NUM> constitutes an electronic component such as an inductor, a transformer, a choke coil or the like. The coil component <NUM> is formed by including the coil assembly body <NUM> and the magnetic cover portion <NUM> as main constituent elements. The coil assembly body <NUM> includes a magnetic-body core <NUM> and a coil <NUM>.

The magnetic-body core <NUM> is provided with a flange portion <NUM> and a pillar-shaped core portion <NUM>, integrally. The magnetic-body core <NUM> is formed by a material of a ferrite core which is obtained by sintering ferrite or of a dust core which is obtained by compression-molding magnetic powders. Here, for the magnetic powders of the dust core, it is possible to use magnetic powders whose main component is iron (Fe) and into which each of silicon (Si) and chromium (Cr) is added by a ratio of 1wt% or more and 10wt% or less. The magnetic powders are excellent in the aspects of rust-prevention property, relative permeability and the like. From the viewpoint of decreasing the core loss, it is allowed for the magnetic-body core <NUM> to be constituted by metal magnetic powders which are obtained by mixing the magnetic powders with an amorphous metal. For the amorphous metal, it is possible to use a carbon-contained amorphous metal whose main component is iron (Fe), in which each of silicon (Si) and chromium (Cr) is contained by a ratio of 1wt% or more and 10wt% or less, and further, in which carbon (C) is contained by a ratio of <NUM>. 1wt% or more and 5wt% or less. Further, it is also allowed for the magnetic-body core <NUM> to be formed so as to contain manganese (Mn) therein.

The flange portion <NUM> has a plate shape and according to the constitution shown in <FIG>, the planar shape of the flange portion <NUM> forms approximately a square shape. However, the planar shape of the flange portion <NUM> is not to be limited to the "approximately square shape" and it is possible to employ various kinds of shapes such as a circle shape, an elliptical shape, a polygonal shape and the like. In addition, at the center portion of the flange portion <NUM>, there is provided the pillar-shaped core portion <NUM> in a standing fashion. The pillar-shaped core portion <NUM> has a cylindrical shape stretching so as to be directed to the upward side (Z1 side), but it is allowed to employ a shape other than the cylindrical shape (to employ a polygonal prism such as a quadrangular prism or the like). The pillar-shaped core portion <NUM> is plugged into a coil hole 42a of the coil <NUM> which will be mentioned later.

In addition, for the coil <NUM>, there is used a rectangular wire <NUM> (corresponding to conductive wire) whose width size is sufficiently larger than the thickness size thereof in which a winding wire portion <NUM> is formed by winding the rectangular wire <NUM> and the coil hole 42a is provided on the inner circumferential side of the winding wire portion <NUM>. Into the coil hole 42a, the pillar-shaped core portion <NUM> mentioned above is plugged. It should be noted that according to the constitution shown in <FIG> and <FIG>, the winding wire portion <NUM> is formed by an edgewise winding in which the axis direction of that winding wire portion <NUM> is provided so as to be in conformity with the axis direction of the pillar-shaped core portion <NUM>. In addition, it is allowed for the lower surface side of the winding wire portion <NUM> to be fixed with respect to the upper surface of the flange portion <NUM> by an adhesive agent. For such an adhesive agent, it is possible to use an insulating-resin adhesive agent.

One terminal 43a of the rectangular wire <NUM> extends from the upper surface side of the winding wire portion <NUM> toward a direction (Y1 side) in parallel with the upper surface 31A of the flange portion <NUM> of the magnetic-body core <NUM> and thereafter, abuts against a side surface 31B on the Y1 side of the flange portion <NUM> in <FIG> in parallel therewith and, further, is bent so as to be directed toward the Y2 side while being abutted against the lower bottom surface 31C of the flange portion <NUM>. The portion abutted against the lower bottom surface 31C is exposed downward from the magnetic cover portion <NUM> and becomes a terminal unit 44a which will be electrically connected to another substrate or the like. Further, the terminal unit 44a is bent so as to be directed upward while being abutted against the side surface 31D on the Y2 side of the flange portion <NUM> and finally, is bent so as to be inclined toward the side of the pillar-shaped core portion <NUM> of the flange portion <NUM>.

Similarly, the other terminal 43b of the rectangular wire <NUM> extends from the lower surface side of the winding wire portion <NUM> toward a direction (Y1 side) in parallel with the upper surface of the flange portion <NUM> and thereafter, abuts against a side surface 31B on the Y1 side of the flange portion <NUM> in <FIG> in parallel therewith and further, is bent so as to be directed toward the Y2 side while being abutted against the lower bottom surface 31C of the flange portion <NUM>. It should be noted that the portion abutted against this lower bottom surface 31C is exposed downward from the magnetic cover portion <NUM> and becomes a terminal unit 44b which will be electrically connected to another substrate or the like. Such a portion becomes the terminal unit 44b, further, is bent so as to be directed upward while being abutted against the side surface 31D on the Y2 side of the flange portion <NUM> and finally, is bent so as to be inclined toward the pillar-shaped core portion <NUM> side of the flange portion <NUM>.

It should be noted that it is also allowed to employ a configuration in which on the lower bottom surface 31C of the flange portion <NUM>, there are provided groove portions (not shown) so as to sag upward for inducing the terminal units 44a, 44b to enter thereinto. Each of these groove portions has a shallower depth compared with the thickness of the rectangular wire <NUM> and each electrode groove houses a portion of the thickness of the terminal unit 44a (44b). For that reason, the downward sides of the terminal units 44a, 44b protrude downward from the lower bottom surface 31C. It is allowed for the upper surface sides of the terminal units 44a, 44b to be adhesively fixed onto the wall surfaces of the groove portions by using an adhesive agent.

The conductive wire can be a round wire having a circular cross-section shape instead of the rectangular wire <NUM> mentioned above. In that case, the terminal units 44a, 44b can be formed by being crushed in flat shapes.

In addition, on the side surface 31D on the Y2 side of the flange portion <NUM>, there are formed side-surface concave portions (not shown) for positioning the terminals 43a, 43b. For this reason, a portion or all of each thickness of the terminals 43a, 43b is housed in each of the side-surface concave portions and it can prevent the terminals 43a, 43b from protruding out of the side surface of the flange portion <NUM>. In addition, the terminals 43a, 43b can be bonded to the wall surfaces of the side-surface concave portions.

Next, there will be explained the magnetic cover portion <NUM>. The magnetic cover portion <NUM> is formed by a material containing magnetic powders and a thermosetting resin. For the magnetic powder, it can use a similar material as that of the magnetic-body core <NUM> mentioned above and it is also allowed to use a different material. In addition, for the resin, a resin which is to be cured under a specific condition is enough, for example any one of a thermosetting resin. That is, a two-component curing-type resin, or a light-curing resin which is cured by an irradiation of UV light or the like is fit for the purpose. When using a thermosetting resin as the resin, the thermosetting resin, for example, an epoxy resin, a phenol resin or a silicon resin can be used.

The magnetic cover portion <NUM> is provided so as to cover the coil assembly body <NUM> totally except the terminal units 44a, 44b mentioned above. It should be noted that it is allowed also for the lower bottom surface 31C of the flange portion <NUM> to be exposed. And it is also allowed for another portion other than the lower bottom surface 31C and the terminal units 44a, 44b within the coil assembly body <NUM> to be exposed. As shown in <FIG>, the magnetic cover portion <NUM> is provided approximately in a rectangular shape. However, the shape of the magnetic cover portion <NUM> can be an arbitrary shape. And the shape thereof is not limited to the "approximately rectangular shape". The magnetic cover portion <NUM> is provided so as to cover the pillar-shaped core portion <NUM> of the magnetic-body core <NUM> and the winding wire portion <NUM> of the coil <NUM>.

Next, there will be explained a constitution of a manufacturing apparatus of a coil component <NUM> (hereinafter, also described merely as "manufacturing apparatus" <NUM>), which is used in order to manufacture the coil component <NUM>.

<FIG> is a drawing showing a constitution of a manufacturing apparatus <NUM> used for the manufacturing of the coil component <NUM>. <FIG> shows a cross-section of the manufacturing apparatus <NUM> and within the whole apparatus, hatchings are omitted with regard to a coil-assembly body <NUM>, an admixture <NUM> and a press member <NUM> for the sake of convenience. The manufacturing apparatus <NUM> includes a base plate portion <NUM>, a lower-side support plate <NUM>, a cylindrical die <NUM>, a lid member <NUM>, a press member <NUM>, a pressurizing mechanism <NUM>, a vibration generating mechanism <NUM> and a control unit <NUM>. Within such a constitution, the die <NUM> is a container which accommodates the coil-assembly body <NUM> and the admixture <NUM> containing magnetic powder and thermosetting resin. The press member <NUM> applies pressure to the admixture <NUM> inside the die <NUM>. The vibration generating mechanism applies vibration to the admixture <NUM> inside the die <NUM> and the admixture <NUM> is filled inside the die <NUM>. Further, the manufacturing apparatus <NUM> of the first embodiment of the invention is provided with a depressurizing mechanism <NUM> which at least during the application of vibration by the vibration generating mechanism <NUM>, sets an air pressure of the environment in which the admixture <NUM> is placed to be a negative-pressure lower than the atmospheric pressure. The control unit <NUM> controls the operation timings and the operation conditions of the pressurizing mechanism <NUM>, the vibration generating mechanism <NUM> and the depressurizing mechanism <NUM>.

Within the contents mentioned above, according to the present specification, the wording of "filling" indicates that, compared with the state before the vibration-application, the admixture <NUM> is inputted into the inside of the inner cylindrical portion <NUM> (see <FIG>), and it reaches up to every corner of the inner cylindrical portion <NUM> and the coil-assembly body <NUM> with fewer air gaps (voids) in it.

Hereinafter, there will be explained such respective constitutions sequentially.

The base plate portion <NUM> is a portion which becomes a base of the manufacturing apparatus <NUM> and is a portion for supporting the lower-side support plate <NUM> and the die <NUM>. In addition, the base plate portion <NUM> is a portion which is applied with vibration by the vibration generating mechanism <NUM> which will be mentioned later. Caused by the application of vibration to such a base plate portion <NUM>, the vibration is applied to the admixture <NUM> in an inner cylindrical portion <NUM> of the die <NUM>. It should be noted in the constitution shown in <FIG> that there is formed an exhaust hole <NUM> at the base plate portion <NUM>. This exhaust hole <NUM> communicates with an insertion hole <NUM> of the lower-side support plate <NUM> and it is possible to exhaust air from the inside to the outside of the inner cylindrical portion <NUM>. The exhaust hole <NUM> is connected with the depressurizing mechanism <NUM> through an exhaust hose, a valve or the like, which is not shown.

As shown in <FIG>, in the first embodiment of the invention, it becomes difficult for the admixture <NUM> to penetrate into the insertion hole <NUM> caused by a configuration in which the insertion hole <NUM> is formed at a position facing the lower surface of the flange portion <NUM>. In addition, caused by a configuration in which the insertion hole <NUM> is arranged on the side opposite to the lid member <NUM>, the whole inside of the inner cylindrical portion <NUM> is pressurized and it becomes easy for the air within the inner cylindrical portion <NUM> to be exhausted from the insertion hole <NUM>.

The lower-side support plate <NUM> is a sheet-shaped or thin plate-shaped member and is a portion for sealing the opening portion on the lower side of the inner cylindrical portion <NUM> of the die <NUM>. This lower-side support plate <NUM> is provided with positioning concave-portions <NUM> which are recessed compared with the upper surface of that lower-side support plate <NUM> and the terminal units 44a, 44b of the coil assembly body <NUM> enter into those positioning concave-portions <NUM>. Thus, the position of the coil assembly body <NUM> with respect to the inner cylindrical portion <NUM> of the die <NUM> will be determined.

In addition, the lower-side support plate <NUM> is provided with the insertion hole <NUM> and this insertion hole <NUM> communicates with the exhaust hole <NUM> mentioned above. For that reason, in a case of pressing the admixture <NUM> in the inner cylindrical portion <NUM> of the die <NUM>, it is possible to exhaust the air which exists in the inner cylindrical portion <NUM> toward the outside through the exhaust hole <NUM> and the insertion hole <NUM>.

The die <NUM> is a member which includes a cylindrical outer cylindrical portion <NUM> and the portion surrounded by that outer cylindrical portion <NUM> (portion surrounded by an inner wall 131a of the outer cylindrical portion <NUM>) becomes the inner cylindrical portion <NUM>. Then, it is possible to place the coil assembly body <NUM> in this inner cylindrical portion <NUM>, to fill the admixture <NUM> therein.

It should be noted that the die <NUM> is positioned with respect to the lower-side support plate <NUM> through a positioning member which is not shown. For such a positioning member, it is possible to cite, for example, a configuration in which a protrusion is provided at either one of the lower-side support plate <NUM> and the die <NUM> and a concave portion fitting into that protrusion is provided at the other one thereof. Also it is allowed to use another configuration for the positioning member. In addition, it is preferable for the inner wall 131a to be coated with a release agent beforehand. In a case of coating the release agent, it is possible, when carrying out an ejecting-step S408 mentioned later, to easily eject from the inner cylindrical portion <NUM> an integrated object formed by molding the admixture <NUM> and the coil assembly body <NUM>.

The lid member <NUM> is a member which is placed so as to cover the admixture <NUM> from the upward side (Z1 side) of the inner cylindrical portion <NUM> after the admixture <NUM> is filled in the inner cylindrical portion <NUM>. It is preferable for this lid member <NUM> to be formed by a resin material having excellent mold-release characteristics. For one example of such a resin material, it is possible to use a fluorine resin material such as polytetrafluoroethylene (PTFE) or the like. It should be noted that there is no limitation for the thickness of the lid member <NUM> in particular, in which it is allowed to employ a member having a so-called sheet shape and other than this shape, a plate shape, a block shape or the like. In addition, the lid member <NUM> is provided to be approximately the same as the shape of the inner cylindrical portion <NUM> when viewed in plan view and it is possible to press the admixture <NUM> which is filled in the inner cylindrical portion <NUM> excellently while preventing the admixture <NUM> from leaking from the gap between the lid member <NUM> and the inner wall 131a of the outer cylindrical portion <NUM>.

The press member <NUM> is a member for pressing the lid member <NUM> from the upper side thereof and is provided to have a smaller diameter than that of the lid member <NUM>. For that reason, it is possible to prevent the press member <NUM> from colliding with the outer cylindrical portion <NUM>. In addition, it is preferable for the press member <NUM> to be provided to have a larger thickness than that of the lid member <NUM>. It is possible for the press member <NUM> to use, for example, a block-shaped member. However, the press member <NUM> is not to be limited to the block-shaped member and it is allowed to use, for example, an arm or the like which presses the lid member <NUM> toward one direction.

The pressurizing mechanism <NUM> is a mechanism for applying a pressing force onto the press member <NUM> from the upper side of the press member <NUM>. Owing to such a pressurizing mechanism <NUM>, it becomes possible to pressurize the admixture <NUM> which exists in the inner cylindrical portion <NUM>. It should be noted that it is allowed to employ a pressurizing mechanism <NUM> which applies a predetermined pressing force continuously and it is also allowed to employ a pressurizing mechanism which applies a predetermined pressing force periodically.

For the pressurizing mechanism <NUM> of the first embodiment of the invention, it is supposed that the pressure is to be applied with respect to an area of from <NUM><NUM> to <NUM><NUM> per one product, in which it is preferred to apply a pressure of <NUM>. 01MPa or more and 20MPa or less onto such an area. Further, it is more preferable to apply a pressure of <NUM>. 5MPa or more and 2MPa or less.

The vibration generating mechanism <NUM> is a mechanism which is attached to the base plate portion <NUM> and is a mechanism for applying a vibration with respect to that base plate portion <NUM>. The vibration generating mechanism <NUM> corresponds to the vibration applying member. It is possible for the vibration generating mechanism <NUM> to employ, for example, a mechanism using a ball vibrator <NUM> and a compressor (not shown). The ball vibrator <NUM> is provided with an iron-steel-made iron ball and a cylindrical case for rotating the iron ball in which there is supplied a compressed air into the inside of the cylindrical case from a compressor. The iron ball rotates at high-speed, caused by the pressure of the compressed air which is supplied into the inside of the cylindrical case, and caused by that action, the vibration is applied to the base plate portion <NUM>.

The vibration applied to the base plate portion <NUM> is applied to the lower-side support plate <NUM>, the die <NUM> and the admixture <NUM>. The admixture <NUM> vibrates by the applied vibration and the molding-degree thereof becomes high. Here, the wording "molding-degree" expresses "degree of being easily-molded" in which the material deforms and becomes another shape, wherein the state that the molding-degree is high indicates a state in which it is easy for that material to become a predetermined shape under a certain condition and the state that the molding-degree is low indicates a state in which it is difficult for that material to become a predetermined shape even under a similar condition. The molding-degree of the admixture <NUM> has a correlation with the applied vibration-frequency. The inventor etc. of the present invention found out a range of the vibration frequency which largely improves the molding-degree of the admixture <NUM> and by using this frequency, the vibration is applied to the base-plate portion <NUM>. The vibration which it is preferable to apply to the base-plate portion <NUM> of the first embodiment of the invention has a frequency of, for example, <NUM> or more and <NUM> or less. It should be noted that it is allowed that the vibration applied to the admixture <NUM> of the first embodiment of the invention is to be caused by vibrating the base-plate portion <NUM> in a vertical direction or to be formed by vibration in a horizontal direction. In other words, it is allowed for the direction of the vibration to be a perpendicular direction with respect to the pressurizing direction of the pressurizing mechanism <NUM> and it is also allowed to be the same direction therewith.

By the fact that the molding-degree is increased, the admixture <NUM> enters into every corner of the inner cylindrical portion <NUM> and into air gaps of the coil-assembly body <NUM>, into which the admixture <NUM> did not enter before the vibration-application. In addition, there exists no air gap or the like in the admixture <NUM> thereof.

Here, there is employed a mechanism for the ball vibrator <NUM> in which the iron ball does not move in a linear direction one-dimensionally but rotates, as mentioned above, in a circular orbit in the cylindrical case. For that reason, the base plate portion <NUM> is applied with a vibration which is not linear but planar (two-dimensional) caused by the ball vibrator <NUM>. Therefore, the admixture <NUM> can be filled into the air gap more excellently. It should be noted that it is allowed for the rotational surface formed by the rotation of the iron ball to be set in parallel with the XY plane. Also it is allowed to let the rotational surface, to be in parallel with the Z direction, like a XZ plane or ZX plane is. In addition, it is also allowed for the ball vibrator to be mounted so as to be inclined with respect to the XY plane, the YZ plane or the ZX plane by a predetermined angle. Furthermore, there is no limitation of the mounting method thereof. Among those methods above, when vibrating the base-plate portion <NUM> toward the perpendicular direction with respect to the pressurizing direction of the pressurizing mechanism <NUM>, it is possible to vibrate the admixture <NUM> by the vibration generating mechanism <NUM> preferably while maintaining the pressurizing state made by the pressurizing mechanism <NUM>.

It should be noted that the vibration generating mechanism <NUM> is not to be limited to a mechanism which uses the ball vibrator <NUM>. For example, it is allowed for the vibration generating mechanism <NUM> to use a driving device of such a type in which the vibration is generated by mounting a rotational body onto a motor in an eccentric state and by rotating that rotational body. Besides, it is possible for the vibration generating mechanism <NUM> to use various types of driving devices such as driving devices of ultrasonic methods, driving devices of such types using electromagnets and the like.

The depressurizing mechanism <NUM> includes a vacuum pump communicating with the exhaust hole <NUM> which communicates with the inner cylindrical portion <NUM>. It is allowed for the vacuum pump to have any constitution provided that the inside of the inner cylindrical portion <NUM> can be made to have a necessary degree of vacuum for filling the admixture <NUM>. For the first embodiment of the invention, it is assumed that the depressurizing mechanism <NUM> has such an ability that it is possible to make the air pressure inside the inner cylindrical portion <NUM> to be from a pressure less than the atmospheric pressure to the atmospheric pressure. And specifically, it is assumed that there can be achieved a degree of vacuum from <NUM>-<NUM>Pa or more until <NUM><NUM>Pa or less. For a vacuum pump which can achieve such a degree of vacuum, there exist, for example, a rotary pump, a diaphragm pump and the like. In addition, it is also allowed for the depressurizing mechanism <NUM> to include a vacuum meter or the like which monitors the degree of vacuum in the inner cylindrical portion <NUM>.

The control unit <NUM> has a constitution for controlling the operations of the pressurizing mechanism <NUM>, the vibration generating mechanism <NUM> and the depressurizing mechanism <NUM>. Here, the wording of "the operation of the pressurizing mechanism <NUM>" indicates "the start of pressurizing", "the end timing", "applying the pressure to the lid member <NUM>", and the like. In addition, the wording of "the operation of the vibration generating mechanism <NUM>" indicates "the start of vibration-application", "the end timing", "the vibration frequency", and "the direction" thereof. Further, the wording of "the operation of the depressurizing mechanism <NUM>" indicates "the start of depressurizing", "the end timing", "controlling the air pressure inside the inner cylindrical portion <NUM>", and the like. For the control unit <NUM> of the first embodiment of the invention, it is allowed to employ a configuration of controlling each of the mechanisms automatically in accordance with a preset condition. And it is also allowed to employ a configuration in which an operator inputs or manually carries out at least a part of the operation. Such a control unit <NUM> can be realized also by using a general-purpose computer, a dedicated microcomputer or the like.

Next, there will be explained a manufacturing method of a coil component, which is carried out by a manufacturing apparatus of a coil component as explained above.

<FIG> is a flowchart showing a manufacturing method of a coil component according to the first embodiment of the invention. The coil manufacturing method of the first embodiment of the invention is a manufacturing method of a coil component for forming a coil-assembly body <NUM> in which a coil is mounted on a magnetic-body core <NUM>. As shown in <FIG>, in the coil manufacturing method of the first embodiment of the invention, there exist the coil-assembly body <NUM>; an input step (S401) for inputting the admixture <NUM> which includes the magnetic powder and the resin into the inner cylindrical portion <NUM> which is a container; a pressurizing step (S402) for applying pressure onto the admixture <NUM> which is inputted into the inner cylindrical portion <NUM>, a depressurizing step (S403) for depressurizing an air pressure of the environment, in which the admixture <NUM> is placed, to become a negative-pressure lower than the atmospheric pressure at least during the pressurizing process in the pressurizing step (S402); a vibration-application step (S404) for applying vibration onto the admixture <NUM> and filling the admixture <NUM> in the inner cylindrical portion <NUM> at least during the depressurizing process in the depressurizing step (S403); and a curing step (S409) for curing the resin, which is contained in the admixture <NUM>, for the integrated object of the admixture and the coil-assembly body <NUM>, which passed through the depressurizing step S403 and the vibration-application step S404. Here, the wording of "at least during the pressurizing process in the pressurizing step" expresses that the depressurizing step S403 may start before the start of the pressurizing step <NUM> or may start after the start thereof. In addition, the wording of "at least during the depressurizing process in the depressurizing step" expresses that the vibration-application step S404 may start before the start of the depressurizing step S403 or may start after the start thereof. It should be noted in the first embodiment of the invention that the explanation will be carried out by citing an example in which a thermosetting resin is used for the step S409. For this reason, in the abovementioned steps, all the steps other than the curing step S409 are carried out under the room temperature. However, as described above, the first embodiment of the invention is not to be limited to using a thermosetting resin and it is also allowed to use a two-component curing-type resin or a light-curing resin.

Hereinafter, there will be explained the abovementioned respective steps.

In the input step S401 of the first embodiment of the invention, the coil assembly body <NUM> is placed on the lower-side support plate <NUM> in the inner cylindrical portion <NUM>, and the admixture <NUM> is inputted into the inside of the inner cylindrical portion <NUM>. At that time, caused by a configuration in which the terminal units 44a, 44b are made to enter into positioning concave-portions of the lower-side support plate <NUM>, which are not shown, the coil assembly body <NUM> is positioned in the inner cylindrical portion <NUM>.

The admixture <NUM> of the first embodiment of the invention is a putty-like admixture (in other words, clay-like admixture) obtained by mixing metal-made magnetic powders and a resin and by adding a solvent thereto. For that reason, for example, in a case of forming the admixture <NUM> to have a certain shape, the molding-degree thereof becomes an identical or similar viscosity as that of the clay and the shape thereof can be maintained. It should be noted that the magnetic cover portion <NUM> is formed by the admixture <NUM> and therefore, the magnetic powders and the resin are made by the same materials as those of the above-mentioned magnetic cover portion <NUM>. In addition, it is possible for the solvent to arbitrarily utilize a well-known organic solvent such as acetone, MEK (methyl ethyl ketone), ethanol, α-Terpineol, IPA (isopropyl alcohol) or the like.

As an example of the admixture <NUM>, there can be cited an admixture obtained by mixing the metal magnetic powders and the epoxy resin under a condition in which the composition ratio there-between is selected as <NUM>:<NUM> to <NUM>:<NUM> (including both of the end-values) by mass-ratio. Further, it is possible to prepare the viscosity of the admixture <NUM> by adding the solvent selectively. For one example of the metal magnetic powders, it is possible to cite powders in which amorphous metal magnetic powders containing at least iron, silicon, chromium and carbon are mixed with iron-silicon chromium based alloy powders by mass-ratio <NUM>:<NUM>.

In addition, it is possible to use a terpineol for the solvent which is added to the admixture <NUM> in which the additive amount of the solvent is made to be less than 5wt% with respect to the mass of the admixture <NUM>. Thus, it is possible to set the admixture <NUM> in a putty state having comparatively high viscosity. At that time, the viscosity of the admixture <NUM> becomes within a range of 30Pa·s to 3000Pa·s.

In addition, in a case of inputting the admixture <NUM> into the cylindrical portion <NUM>, the block body of the admixture <NUM> is formed beforehand so as to obtain a proper amount of the admixture <NUM> and, in addition, so as to form a shape which is easily inputted to the inner cylindrical portion <NUM>. Then, after placing the coil assembly body <NUM> on the lower-side support plate <NUM>, the block body of the admixture <NUM> is placed on the upper portion of the coil assembly body <NUM>.

Next, in the first embodiment of the invention, the pressurizing step S402 is carried out. In the pressurizing step S402, the lid member <NUM> is placed on the upper portion of the admixture <NUM> and after placing the press member <NUM> on the upper portion of the lid member <NUM>, the pressurizing mechanism <NUM> is activated. Thus, the lid member <NUM> is pressed by the pressurizing mechanism <NUM> toward the Z2 direction shown in <FIG> and the pressurizing mechanism <NUM> applies pressure onto the admixture <NUM>. The pressurized admixture <NUM> enters into the air gap inside the inner cylindrical portion <NUM> and is to be filled into the inside of the inner cylindrical portion <NUM>. Such a pressurizing step S402 of this embodiment is a step in which the inner cylindrical portion <NUM> is filled with the admixture <NUM> without substantially changing the volume of the admixture <NUM> eliminating the air gap thereof. For this reason, the pressurizing step S402 is designed to be different from a well-known compression-step in which the processed-object such as ferrite, iron powder or the like is compressed by high pressure and the volume thereof is reduced significantly. While a high pressing force of around <NUM> tons/cm2 to a few tons/cm2 is generally loaded onto the processed-object in the well-known compression-step, it is enough in the pressurizing step S402 of the first embodiment of the invention if a pressing pressure of, for example, around <NUM>/cm2 to <NUM>/cm2 is to be loaded onto the admixture <NUM>. Therefore, in the pressurizing step S402, also the damage to the die <NUM> becomes less compared with the well-known compression step and there can be obtained such a merit that the selective range of the material for the die <NUM> will be widened. In the pressurizing step S402, the position of the press member <NUM> is maintained also during the succeeding step of depressurizing or the like and the pressure is kept on being applied to the admixture <NUM>.

Next, in the first embodiment of the invention, the depressurizing step S403 is carried out. In the depressurizing step, there is maintained the state in which the pressurizing mechanism <NUM> pressurized the press member <NUM> and the lid member <NUM>. It means that the maintenance of this pressurizing state is one part of the pressurizing step S402 and that it is also a part of the vibration-application step S404. In this manner, the control unit <NUM> activates the depressurizing mechanism <NUM> while the admixture <NUM> is pressurized. The depressurizing mechanism <NUM> sets the air pressure inside the inner cylindrical portion <NUM> to be, for example, 100Pa or more and 104Pa or less. The air pressure inside the inner cylindrical portion <NUM> is determined according to the balance between the exhaust ability of the depressurizing mechanism <NUM> and the flow-rate (air tightness in the inner cylindrical portion <NUM>) of the atmospheric air which flows into the inside of the inner cylindrical portion <NUM>.

The vibration-application step S404 of the first embodiment of the invention is a step for applying vibration to the admixture <NUM>. In the vibration-application step S404, the control unit <NUM> controls the vibration generating mechanism <NUM> and the application of the vibration with respect to the admixture <NUM> is started. At that time, in the inner cylindrical portion <NUM>, the admixture <NUM> is pressurized and the internal pressure therein becomes a depressurized state. At that time, the vibration is applied to the base-plate portion <NUM> and the applied vibration is also transmitted to the admixture <NUM>.

With regard to the vibration applied by the vibration generating mechanism <NUM>, the amplitude thereof is designed to be within a range of <NUM> µm to <NUM>. In addition, the frequency of the applied vibration is designed to be within a range of <NUM> to <NUM>. Within such a range, it is preferable, for the first embodiment of the invention, to apply a vibration, whose frequency is particularly <NUM> or more and <NUM> or less, to the admixture <NUM>.

In addition, in the first embodiment of the invention, the time period for applying the vibration by the vibration generating mechanism <NUM> is designed to be within a range of <NUM> second to <NUM> seconds. It should be noted that the time period for applying the vibration is not to be limited to the above-mentioned range and it is allowed to vibrate the admixture <NUM>, for example, for more than <NUM> seconds.

By applying the vibration to the admixture <NUM>, the molding-degree thereof becomes high rapidly. For that reason, when the molding-degree of the admixture <NUM> became high rapidly, by pressurizing the admixture <NUM> in one direction under the condition mentioned above. And by depressurizing the ambient pressure, the admixture <NUM> enters into the air gaps sufficiently in the inner cylindrical portion <NUM> and is filled in the inner cylindrical portion <NUM> fully. In addition, by pressurizing the admixture <NUM> and placing it under a depressurizing environment, the air gaps occurring in the admixture <NUM> are crushed and will disappear. Caused by such a phenomenon, it happens that in the first embodiment of the invention, the admixture <NUM> will cover the whole circumference of the coil-assembly body <NUM> without any air gaps and it is possible to eliminate the filling defect.

After starting the pressurizing step S402, the depressurizing step S403 and the vibration-application step S404, in the first embodiment of the invention, the control unit <NUM> judges the end timings of those respective steps (S405). It is allowed to judge the end timing of each step, for example, by a predetermined time-lapse from the start of the each step. In addition, it is allowed to employ a configuration for the respective end timings of the steps in which the vibration-stopping step S406 and the depressurizing step S407 sequentially in this order. However, the depressurizing step S403, the vibration-application step S404, the vibration-stopping step S406 and the depressurizing step S407 are not limited to a configuration of being carried out by the sequential order shown in the flow chart of <FIG>. For example, it is allowed to start the depressurizing step S403 and the vibration-application step S404 to simultaneously and it is also allowed to carry out the vibration-application step S404 preceding to the depressurizing step S403. In addition, if the lid member <NUM> is a member closable when applying the pressure to the admixture <NUM>, it is allowed to carry out the pressurizing step S402 simultaneously in addition to the depressurizing step S403 and the vibration-application step S404.

Further, it is allowed to carry out the vibration-stopping step S406 and the depressurizing step S407 simultaneously and it is also allowed to carry out the depressurizing step S407 preceding to the vibration-stopping step S406.

Next, in the first embodiment of the invention, the ejecting-step S408 is carried out. In the ejecting-step S408, the pressurization of the admixture <NUM> is released by a configuration in which the control unit <NUM> controls the pressurizing mechanism <NUM> and the press member <NUM> is lifted up toward the Z1 direction shown in <FIG>. After the release of the pressurization, the integrated object of the admixture <NUM> and the coil-assembly body <NUM> is ejected from the inside of the inner cylindrical portion <NUM>. At that time, the top surface portion of the admixture <NUM> is in close contact with the lid member <NUM> and therefore, it is possible to eject the integrated object when the upper surface is in close contact with the lid member <NUM> by pushing the integrated object upward, for example, by inserting a pin shaped push-up member into the lower surface of the integrated body in the inner cylindrical portion <NUM>.

Next, in the first embodiment of the invention, the curing step S409 is carried out. In the curing step S409, the admixture <NUM> in the ejected integrated object is thermally-cured by being heated up to the thermosetting temperature or more. At that time, the solvent contained in the admixture <NUM> is removed by being volatilized. Then, after a state in which the admixture <NUM> is cured sufficiently and becomes a magnetic cover portion <NUM>, the lid member <NUM> is removed from the upper surface of the integrated object. Thus, the coil component <NUM> is formed.

It should be noted with regard to the ejecting-step S408 and the curing step S409 that it is not to be limited to carrying out such a procedure as mentioned above. More specifically, it is allowed, before carrying out the ejecting-step S408, to carry out the curing step S409 when the integrated object is filled in the inner cylindrical portion <NUM>. Then, it is allowed, after curing the integrated object completely in the curing step S409, to carry out the ejecting-step S408.

In addition, in the first embodiment of the invention, the curing step S409 of the first stage is carried out at a first temperature before carrying out the ejecting-step S408, in which the admixture <NUM> of the integrated object is to be semi-cured. At that time, while the first temperature is selected to be less than the thermosetting temperature of the thermosetting resin, the first temperature is made to be a temperature by which the solvent contained in the admixture <NUM> is volatilized so as to semi-cure the integrated object. Thereafter, the ejecting-step S408 is carried out and the integrated object containing the semi-cured admixture <NUM> is ejected from the inner cylindrical portion <NUM>. Then, the curing step S409 of the second stage is carried out at a second temperature which is higher than the first temperature. At that time, the second temperature made to be equal to or higher than the thermal-cure temperature of the thermosetting resin. It should be noted that it is allowed for the first temperature to be equal to or higher than a curing start temperature of the thermosetting resin and also lower than a complete curing temperature.

In addition, it is allowed to carry out a post-treatment step after carrying out the curing step S409. For the post-treatment step, there can be cited processes such as a polishing step of the surface of the magnetic cover portion <NUM>, a coating-formation step by using a thermosetting resin or the like, and the like.

According to the first embodiment of the invention as explained above, it is possible to prevent air gaps which are not filled with the admixture <NUM> from being formed in the inner cylindrical portion <NUM> of the die <NUM>. More specifically, the putty-like admixture <NUM> has a high viscosity and even if the admixture <NUM> inputted into the inner cylindrical portion <NUM> is pressurized, there is a fear that a place which is not sufficiently filled with the admixture <NUM> (filling defect) is caused in the inner cylindrical portion <NUM>.

However, in the first embodiment of the invention, after the admixture <NUM> is inputted into the inner cylindrical portion <NUM> in the pressurizing step S402, the depressurizing step S403 is carried out and the admixture <NUM> is pressed onto the inner wall of the inner cylindrical portion <NUM>, and concurrently, the vibration-application step S404 is carried out and the molding-degree of the admixture <NUM> is heightened. It should be noted that as mentioned before, the wording "molding-degree" expresses "degree of being easily-molded" in which the material deforms and becomes another shape and therefore, the admixture <NUM>, whose molding-degree is heightened, deforms in conformity with the shapes of the inner cylindrical portion <NUM> and the coil-assembly body <NUM> and it becomes easy for the admixture to enter into the air gaps of the inner cylindrical portion <NUM> and the air gaps of the coil-assembly body <NUM>. Therefore, in the first embodiment of the invention, it is possible to prevent the places which are not filled with the admixture <NUM> (filling defect) from occurring in the inner cylindrical portion <NUM>. In such a first embodiment of the invention, it is possible to uniformize the quality of the coil component <NUM> which is formed by way of the subsequent ejecting-step S408, curing step S409 and the like.

Next, there will be explained a second embodiment of the present invention.

<FIG> is a drawing for explaining a manufacturing method of a coil component according to a second embodiment of the present invention. In the second embodiment of the invention, with regard to similar constitutions as the constitutions which were explained in the first embodiment of the invention, similar reference numerals are applied thereto and the explanations and illustrations thereof will be omitted.

The manufacturing method of the coil component in the second embodiment of the invention is a method having a configuration, for the depressurizing step S403 in the first embodiment of the invention, in which a mold body <NUM>, which includes cavity portions <NUM> corresponding to a plurality of containers, is depressurized at once in a depressurizing chamber <NUM> which can accommodate the plurality of containers. In order to realize such a manufacturing method of a coil component, the manufacturing apparatus (<NUM>) of a coil component in the second embodiment of the invention includes a mold body <NUM> provided with a plurality of cavity portions <NUM>; a base-plate portion <NUM> which supports the mold body <NUM>; a lid member <NUM> which pressurizes the admixture <NUM> inputted into the mold body <NUM>; a press member <NUM>; and a pressurizing mechanism <NUM>. The mold body <NUM>, the base-plate portion <NUM> and the lid member <NUM> are housed in the depressurizing chamber <NUM>.

Further, for the manufacturing apparatus <NUM> of the second embodiment of the invention, an exhaust hole <NUM> is formed at the base-plate portion <NUM> and there is included a depressurizing mechanism <NUM> which depressurizes the inside of the depressurizing chamber <NUM> through the exhaust hole <NUM>. Further, the manufacturing apparatus <NUM> includes a vibration generating mechanism <NUM> which applies a vibration to the admixture <NUM> through the base-plate portion <NUM>, a pressurizing mechanism <NUM> and a control unit <NUM> which controls the operations of the depressurizing mechanism <NUM>, the vibration generating mechanism <NUM> and the pressurizing mechanism <NUM>. It should be noted that although the illustration is omitted, exhaust paths which communicate with the respective cavity portions <NUM> and the exhaust hole <NUM> are formed in the mold body <NUM> and when the depressurizing mechanism <NUM> starts the exhausting, the air is exhausted, by the depressurizing mechanism <NUM>, from the inside of the cavity portion <NUM> by passing through the exhaust hole <NUM>.

The mold body <NUM> is formed by a resin material having a good mold-releasing property. For the resin material of the mold body <NUM>, it is possible to cite a silicone rubber material as an example. As shown in <FIG>, the mold body <NUM> has a constitution in which an integrated jig <NUM> and a bottom portion <NUM> are formed integrally. The mold body <NUM> has flexibility and also is provided with a plurality of arranged cavity portions <NUM>. In the input step S401 shown in <FIG>, each of the plurality of cavity portions <NUM> is inputted with the admixture <NUM> and the coil-assembly body <NUM>. Specifically, the coil-assembly body <NUM> is inputted into the cavity portion <NUM> and the coil-assembly body <NUM> is fixed by being fitted in a concave portion (not-shown) which is provided at the bottom surface of the cavity portion <NUM>. Then, the admixture <NUM> is inputted into the cavity portion <NUM>.

Next, in the second embodiment of the invention, the mold body <NUM> is attached with the lid member <NUM> and the press member <NUM> is placed on the lid member <NUM>. The control unit <NUM> pressurizes the admixture <NUM> by the pressurizing mechanism <NUM> and subsequently, the inside of the depressurizing chamber <NUM> is depressurized by the depressurizing mechanism <NUM>, and the vibration is applied to the admixture <NUM> through the base-plate portion <NUM> by controlling the vibration generating mechanism <NUM>. According to the operations mentioned above, it is possible for the second embodiment of the invention to manufacture integrated objects formed by the plurality of coil-assembly bodies <NUM> and the admixtures <NUM> simultaneously in the plurality of cavity portions <NUM>.

It should be noted in the second embodiment of the invention that the explanation thereof will be carried out by citing an example of using a thermosetting resin for the resin, similarly to the first embodiment of the invention. However, the second embodiment of the invention is not to be limited either by using the thermosetting resin for the resin and it is also allowed for the resin to use, inter alia, a two-component curing-type resin or a light-curing resin. In the second embodiment of the invention, the plurality of coil components <NUM> (see <FIG>, <FIG>) are molded by thermally-curing the admixtures <NUM> respectively in the mold body <NUM> and then, it is good choice if the plurality of molded coil components <NUM> are taken out from the cavity portions <NUM> by bending the mold body <NUM> in a way of a reverse-bending toward the arrangement direction of the cavity portions <NUM>.

Next, there will be explained an experimental example helpful for understanding the first embodiment of the invention and the second embodiment of the invention which were explained above. This experimental example is an example presenting the result obtained by an experiment with regard to a matter that the molding-degree of the admixture <NUM> will become high by applying the vibration while pressurizing the admixture <NUM>.

<FIG> is a drawing for explaining an unclaimed embodiment referring to an apparatus which was used for the experiment of this example. The apparatus shown in <FIG> includes a cylinder <NUM> and a pressurizing pin <NUM> which pressurizes the admixture <NUM> in the cylinder <NUM>. In this experimental example, with respect to the admixture <NUM> in the cylinder <NUM>, there is applied from the lower side in <FIG> a vibration V whose frequency changes continuously while there is applied a pressure by the pressurizing pin <NUM>. The cylinder <NUM> is formed with a discharge port <NUM> and the admixture <NUM> applied with the pressure and the vibration is discharged from the discharge port <NUM> to the outside of the cylinder <NUM>. The discharge amount of the admixture <NUM> changes depending on the molding-degree of the admixture <NUM> and it is conceivable that the lower the molding-degree is the greater the discharge amount becomes.

It should be noted in this experimental example that the inner diameter of the discharge port <NUM> was made to be <NUM>. In addition, the frequency range of the vibration V was made to be from <NUM> to <NUM>.

With regard to this experimental example, the pressurizing pin <NUM> applies a pressure of <NUM>. 5MPa or more and 2MPa or less with respect to the admixture <NUM>. The viscosity of the admixture <NUM> is in a range of 107cPs or more and 1012cPs or less, more preferably, in a range of <NUM> × 1010cPs or more and 1011cPs or less. In addition, in a case of defining the viscosity-range of the admixture <NUM> by making the resin content as an index, the range of the resin content is from 5Vol% or more to 80Vol% or less. Further, in this experimental example, the pressure and the vibration V are applied to the admixture <NUM> for <NUM> seconds.

<FIG> is a graph presenting the result obtained by an experiment that was carried out by using the apparatus according to the unclaimed embodiment shown in <FIG>. The horizontal axis of the graph shown in <FIG> indicates the frequency (vibration number) of the vibration V which was applied to the admixture <NUM>, and the vertical axis thereof indicates the amount of the admixture <NUM> which was discharged from the discharge port <NUM> during the application of the pressure and the vibration V. As shown in <FIG>, the discharge amount of the admixture <NUM> ascends with a steep inclination from around a frequency exceeding <NUM> and reaches a peak at <NUM>. The discharge amount descends comparatively steeply after exceeding the frequency <NUM> of the vibration V. According to <FIG>, it is understood, in this experimental example, that it is possible to heighten the molding-degree of the admixture <NUM> efficiently by applying a frequency of <NUM> or more and <NUM> or less onto the admixture <NUM>.

Claim 1:
A manufacturing method of a coil component (<NUM>) for forming a coil-assembly body (<NUM>) in which a coil (<NUM>) is mounted on a magnetic-body core (<NUM>), comprising the steps of:
inputting the coil-assembly body (<NUM>) and a clay-like admixture (<NUM>) containing a magnetic powder, a resin and a solvent into a container (<NUM>, <NUM>, <NUM>,);
applying a pressure onto the admixture (<NUM>) in the container (<NUM>, <NUM>, <NUM>,);
depressurizing the inside of the container while the coil-assembly and the clay-like admixture (<NUM>) are in the container and the clay-like mixture (<NUM>) is pressurized, the inside of the container being at a negative-pressure lower than the atmospheric pressure due to operation of a vacuum pump communicating with the inside of the container via an exhaust hole (<NUM>) in the container;
applying a vibration onto the clay-like admixture (<NUM>) at least during the depressurizing process; and
curing the resin contained in the clay-like admixture (<NUM>) to form the coil component integrating the admixture (<NUM>) and the coil-assembly body (<NUM>) after stopping of the depressurizing and the applying of the vibration.