WO2007004483A1

WO2007004483A1 - Method for manufacturing laminated coil and laminated coil

Info

Publication number: WO2007004483A1
Application number: PCT/JP2006/312872
Authority: WO
Inventors: Shinji Kudo
Original assignee: Shinji Kudo
Priority date: 2005-07-01
Filing date: 2006-06-28
Publication date: 2007-01-11
Also published as: JP2007012969A

Abstract

A method for manufacturing a laminated coil being employed in a choke coil or a transformer for electric circuits. The method is suitable for mass production because the manufacturing process is simplified and can manufacture a laminated coil of excellent quality at a low cost. A laminated coil is also provided. In the method for manufacturing a laminated coil, a flat conductive sheet coil (2) formed by being wound spirally by a single turn or a plurality of turns and provided with a joint (8) in the vicinity of the end is employed, each sheet coil is coated with a filmlike insulating material (10) excepting the joint (8), and a low melting point metal (12) is applied to the joint (8). The sheet coils (2) are laminated such that the insulating material (10) is interposed between them and the joints (8) oppose each other, and then the entirety of laminated coil is heated to melt the low melting point metal (12) deposited on the joints so that the joints (8) of the sheet coils are connected electrically thus forming a coil spirally.

Description

Specification

Manufacturing method of laminated coil and laminated coil technical field

The present invention relates to a method for manufacturing a laminated coil used for a choke coil or a transformer for an electric circuit, and a laminated coil.

Background art

Conventionally, a coil for an electric circuit, for example, a choke coil, is an electric wire (a copper wire such as a magnet wire) with an insulating coating wound around a core material such as a silicon steel plate or a ferrite core at least once. Especially when dealing with large currents, use thick wires that have been wound.

[0003] Although there is no problem with the current flowing through the coil even when a general copper wire is wound when the frequency is several kHz or less, when the frequency of the current is high, the current flows to the center of the conductor due to the skin effect. A phenomenon that stops flowing through the part occurs. In order to avoid this skin effect, the skin effect is not a problem. The power to wire thin copper wires in parallel or the method of winding plate-like copper wire instead of round or copper wire. Is adopted.

[0004] For this reason, a coil using a printed circuit board has been developed to break away from the conventional winding force!

In order to connect such a printed circuit board coil to the coil of the next layer to be overlapped, a process such as making a hole in the base material which is an insulating layer and embedding a conductive pin for connecting to the hole is required. It becomes. For this reason, when forming a coil in multiple layers, an inner via is formed as a connection hole between layers sandwiching an insulating layer, and a printed coil is formed by avoiding unnecessary connection holes. is required.

[0005] As another example, Patent Document 1 discloses a thin coil component and a manufacturing method thereof.

As shown in FIG. 9, a plurality of insulating materials 54 having conductor coil patterns 52 and 53 provided on one or both sides are laminated, and through holes 56 and 56 for connecting the inner ends of the respective coil patterns. Through-holes 60 are also provided in the pads 58, and the inner walls of these through-holes are squeezed to fix the conductors, whereby the inner ends are electrically connected to form a laminated coil. Patent Document 2 also describes an inductance element in which a large current is achieved by spirally winding a rectangular wire in the axial direction. [0006] Patent Document 1: Japanese Patent Laid-Open No. 10-32129

Patent Document 2: Japanese Patent Laid-Open No. 2003-17328

Disclosure of the invention

Problems to be solved by the invention

[0007] However, the method of winding the plate-like copper wires and winding the copper wires in parallel poses a problem of labor and cost such as the winding processing, terminal processing, and pin binding processing. In the method using a printed board, there is a problem that the processing cost and material cost of the printed board are increased.

[0008] In addition, the conventional printed circuit board coil has a problem in that it takes a lot of labor and costs such as the embedding of the pins or the processing related to the inner via, and prevents miniaturization. The laminated coil described in Patent Document 1 also requires a process of providing a through hole and fixing the conductor to the inner wall of the through hole with a mess, and these efforts and costs are problematic.

[0009] The present invention has been made to solve the above-described problems. A manufacturing method of a laminated coil that has a simple manufacturing process and is suitable for mass production, and is excellent in quality at low cost. An object is to provide a laminated coil.

Means for solving the problem

[0010] In order to solve the above technical problem, the method for manufacturing a laminated coil according to the present invention is formed as a single turn or a plurality of turns in a spiral shape as shown in FIG. Using the flat conductive sheet coil 2 provided with the connection part 8 on the part and the back part or on one surface part, the sheet coil is separated on one side or both sides of the sheet coil except for the connection part 8. Apply the edge material 10 and apply the low melting point metal 12 to the connecting part 8 to connect the sheet coil 2 with the connecting parts 8 of the overlapping sheet coils facing each other. The winding direction is the same when laminated, and when laminating, the insulating material 10 is interposed between the overlapping sheet coils 2, and the connecting portions 8 are opposed to each other. The sheet coil 2 is stacked and the stacked sheet coil is stacked. Heating the whole, to melt the low melting point metal 12 attached to the connecting section, it is that the formation of the coil spirally electrically connecting the connecting portion 8 between the sheet coil. At this time, the sheet coils at both ends of the layer of the laminated coil need only be provided with connection portions on one surface. [0011] The method for manufacturing a laminated coil according to the present invention is such that a thermosetting adhesive 14 is interposed between the stacked sheet coils 2 and the sheet coils are bonded to each other by the heating.

[0012] The method for manufacturing a laminated coil according to the present invention is that the insulating material 10 is an epoxy resin having 2 to 4 oxysilane rings using a 2 to 4 base acid anhydride as a curing agent.

[0013] The method for manufacturing a laminated coil according to the present invention is that the insulating material 10 is an epoxy resin having 2 to 4 oxysilane rings using imidazole as a hardener.

[0014] In addition, the method for manufacturing a laminated coil according to the present invention uses, as the insulating material, a 2 to 4 oxysilane ring epoxy resin using a polyimide resin or a polyamideimide resin as a curing agent. .

The method for manufacturing a laminated coil according to the present invention is that tin, lead, or solder is used as the low melting point metal 12.

The method for manufacturing a laminated coil according to the present invention is that the sheet coil 2 is formed by punching a copper plate into a rectangular loop shape. In the method for manufacturing a laminated coil according to the present invention, after the heating, the laminated sheet coil 2 is coated with a molding material 20 mixed with iron powder.

In addition, the laminated coil according to the present invention is manufactured by any one of the above-described laminated coil manufacturing methods.

The invention's effect

[0018] According to the method for manufacturing a laminated coil according to the present invention, at the time of lamination, an insulating material is interposed between the overlapping sheet coils, and the sheet coils are stacked so that the connection portions face each other. The entire laminated sheet coil is heated to melt the low-melting point metal adhering to the connection, and the sheet coil connection is electrically connected to form a spiral coil. Manufacturing by the process is possible, so that mass production can be easily performed and the cost can be reduced, and at the same time, a large current capacity and high quality coil can be easily obtained.

[0019] According to the method for manufacturing a laminated coil according to the present invention, since each sheet coil is bonded to each other by interposing a thermosetting adhesive between the stacked sheet coils. There is an effect that the coils are joined well and the quality of the laminated coil is improved.

[0020] According to the method for manufacturing a laminated coil according to the present invention, since a 2 to 4 oxysilane ring epoxy resin using a 2 to 4 base acid anhydride as a curing agent is used as an insulating material, the glass transition is high. Maintains the form and function as an insulating film between the sheet coils without any alteration (for example, the expansion coefficient becomes high) even after cooling, the temperature at which the low melting point metal is melted and after cooling. In addition, since the thermal expansion is small, there is no other adverse effect such as peeling even after cooling.

[0021] According to the method for manufacturing a laminated coil according to the present invention, since an epoxy resin having 2 to 4 oxysilane rings using imidazoles as a hardener is used as an insulating material, a glass transition temperature as high as the above is used. Even if the temperature at which the low melting point metal is secured is melted, there is an effect that it does not change, and when a polyimide resin or a polyamideimide resin is used as a curing agent, a similar effect is obtained. can get.

[0022] According to the method for manufacturing a laminated coil according to the present invention, since tin, lead, or a solder is used as the low melting point metal, the connecting portions are excellently and accurately connected to each other by fusion bonding of the low melting point metal, and large. If it can withstand electric current, it has a positive effect.

[0023] According to the method for manufacturing a laminated coil according to the present invention, since the sheet coil is formed by punching a copper plate into a rectangular loop shape, the manufacturing is easy, the cost can be reduced, and a coil with a large current capacity is obtained. When it is done, it has a positive effect.

According to the method for manufacturing a laminated coil according to the present invention, after heating, the periphery of the laminated sheet coil is coated with the mold material mixed with iron powder, so that the magnetic flux is induced in the mold material and the efficiency is increased. When the magnetic field lines can be well connected and the inductance of the coil is increased, there is an effect.

[0025] Since the laminated coil according to the present invention is manufactured by any one of the manufacturing methods described above, it can be manufactured by a consistent processing process, which facilitates mass production and reduces costs. There is an effect that can be achieved. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a method for manufacturing a laminated coil and an embodiment of the laminated coil according to the present invention will be described with reference to the drawings. The laminated coil 1 is a coil such as a choke coil for an electric circuit. Used. The laminated coil has a structure in which a single-turn sheet-like coil is laminated to form a multi-turn coil, and a multi-turn sheet-like coil is laminated to form a multi-turn coil. There is.

[0027] As a first embodiment, an embodiment will be described in which a coil is formed by stacking single-turn sheet-like coils. FIG. 1 shows the above-described one-turn sheet coil 2 for each layer. This sheet coil 2 has forms from the first layer to the 15th layer. Each coil has an open loop shape in which the winding direction is rectangular, and a predetermined gap 4 (gap) is formed in part.

[0028] Among these sheet coils, a coil terminal portion 6 is formed at one end of each of the sheet coils at the lowermost end (first layer) and the uppermost end (15th layer) so as to protrude from a rectangular frame. Each of the other end portions is formed with a connection portion 8 that is electrically connected to another sheet coil. The sheet coil 2 from the second layer to the fourteenth layer has other surface portions near one end facing the gap 4 and other back surfaces near the other end. A connecting portion 8 to be connected to the sheet coil is formed.

[0029] The sheet coil 2 is stacked, for example, sequentially from the bottom to the first layer, the second layer, and the third layer. At this time, the gap 4 position of each sheet coil 2 is formed so as to be sequentially shifted by one frame (in the range of the size of the connecting portion) in the same peripheral direction. As a result, the connecting portions 8 of the sheet coils 2 that overlap in the vertical direction face each other. If these are electrically connected and made conductive, a coil with 15 turns can be formed.

Here, the manufacturing process and insulating material of the laminated coil 1 will be described. First, a sheet coil is formed by punching a conductive plate material by a press punching process. Here, the sheet coil 2 from the first layer to the 15th layer is made by punching a copper plate.

[0031] Next, in the printing step, a resin composition obtained by adding a curing agent and a catalyst to epoxy resin as an insulating material 10 on both surfaces (or one surface) of each sheet coil 2 to a predetermined thickness. It is applied by a printing method and cured by heating to form an insulating film. At this time, it is necessary for the connecting portion 8 to remove the target force of the insulating film. This can be done by removing each connecting portion 8 and applying the insulating material 10 at the time of application, or by applying a sheet including the connecting portion 8. There is a method in which an insulating material 10 is applied to the entire coil, and the insulating film at the connection portion is removed later by a mechanical or chemical method. In the form in which the insulating material 10 is applied to one side of each sheet coil 2 described above, the sheet coils 2 are laminated together. In this case, the insulating material 10 is applied to the surface of one of the facing sheet coils 2.

In this embodiment, epoxy resin (bisphenol type epichlorohydrin resin) is used as the insulating material 10. This epoxy resin is excellent in heat resistance, electrical insulation, adhesive strength, and mechanical strength. An acid anhydride (methyltetrahydrophthalic anhydride) was used as a curing agent for this epoxy resin. Here, methyltetrahydrophthalic anhydride is liquid at room temperature, and is convenient for printing and has good workability.

[0033] Through trial production of a laminated coil in-house, a resin composition comprising the above bisphenol type epichlorohydrin resin and the above methyltetrahydrophthalic anhydride as a curing agent has a particularly high glass transition temperature (Tg). It is excellent in heat resistance and effective as the insulating material 10, and the resin composition does not change heat even at the temperature at which the following low melting point metal is melted. It was confirmed by the prototype that there was no. In addition, imidazoles (2-ethyl-4-methylimidazole) were added as a catalyst to the resin composition.

In general, the following epoxy resins having a 2-oxolan ring to 4-oxylan ring system are excellent in heat resistance and can be used as the insulating material 10. Among these, the following resins can be used as the insulating material 10 as confirmed by in-house tests. Examples of the above-mentioned 2-oxylan ring epoxy resins include alicyclic epoxy resins, bisphenol type (A, F type, etc.) monochlorohydrin resins, and bifunctional phenolic type epoxy resins. Examples of 3-oxysilane ring epoxy resins include phenol novolac resins, heterocyclic epoxy resins, and multifunctional epoxy resins. Also, 4-oxosilane epoxy resins include tetrafunctional phenolic epoxy resins. There are resin and tetrafunctional glycidylamine type epoxy resin. As the insulating material, thermosetting resin such as polyimide or polyamideimide, melamine resin and benzoguanamine resin are also confirmed to be good.

[0035] Further, as a curing agent that contributes to heat resistance in combination with the epoxy resin, acid anhydrides of 2 to 4 bases are effective. Of these, materials and catalysts that have been confirmed by in-house tests and are effective as curing agents for the above epoxy resins include the following. Examples of the above two-basic acid anhydrides include methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalate. Trimellitic acid as tribasic acid anhydride, pyromellitic acid, 4,4'-oxydiphthalic anhydride, etc. as 4-basic acid anhydride. In addition, as other curing agents, imidazoles such as 1-cyanoethyl-2-methylimidazole and 2,4-diamino-6- [2'-methylimidazolyl mono (1 ')] ethyl-s-triazine / isocyanuric acid addition salt It has been confirmed that amine-based curing agents, diaminodiphenyl ether, and amine-based curing agents such as 4,4-diaminodiphenylmethane are good. In addition, it is possible to use a resin such as polyimide, polyamide-imide or melamine as a curing agent, and it has been confirmed that excellent heat resistance is exhibited by using it as a curing agent for the epoxy resin. . As the above catalyst, tertiary amines such as 2,4,6-tris (dimethylaminomethyl) phenol, or imidazoles have been confirmed to be excellent in curing acceleration.

[0036] An insulating material using the above-mentioned epoxy resin as the curing agent such as the above acid anhydride or the above imidazoles or amines as the curing agent has an increased glass transition temperature and is excellent in heat resistance. Even when the low melting point metal is melted, the function as an insulating film that does not change heat is not impaired.

After applying the insulating film, the insulating film made of the insulating material 10 on the surface of the connection portion 8 of each sheet coil 2 is removed by a technique such as etching. In this process of removing the insulating film, the insulating film on the surface of the connecting portion 8 is removed by a chemical method such as etching, a mechanical method, or a physical method such as laser beam, high-frequency dielectric heating, or discharge. Thereby, conductive connection portions 8 are formed in the vicinity of the end portions of the front surface portion and the back surface portion of the sheet coil 2, respectively.

[0038] Further, in the next plating step, the low melting point metal 12 is deposited (plated) on the conductive connecting portion 8 of the sheet coil from which the insulating film has been removed. The low melting point metal 12 is preferably tin, lead, solder (tin-lead alloy) or the like. In particular, solder is good when the content of tin is high (60% or more) and the melting point is low. An alloy in which a small amount of nickel, silver, copper, or the like is mixed with tin can be used.

At this time, as shown in FIG. 2, the thickness (M) of the low melting point metal 12 layer plated on the connection portion 8 of each sheet coil 2 is the thickness (W) of the insulating film layer formed by the insulating material 10. Slightly thicker, formed to a degree (M> W). The thickness of the low melting point metal 12 layer is made thicker than the thickness of the insulating film layer of the insulating material 10. This ensures that the 12 layers of low melting point metal in the sheet coil that face each other are fused and connected. The above-mentioned consistent printing process and processing process complete the process such as insulation for each sheet coil.

In the next laminating step, as shown in FIG. 3, the adhesive 14 is applied and applied to one or both sides of the sheet coil 2 leaving the connecting portion 8, and the sheet coils from the first layer to the 15th layer are coated. Are stacked and bonded together. As the adhesive 14, for example, a thermosetting adhesive such as epoxy resin is used. For example, some of these adhesives melt at low temperatures (60 ° C to 80 ° C). When the above-mentioned laminate bonding is performed in this state, and this adhesive is further exposed to high temperatures (120 ° C or higher), The reaction takes place and the adhesive changes into a thermosetting adhesive.

[0041] In the final heating step, the laminated sheet coil is placed in a heating furnace or the like and heated at a predetermined temperature. This heating temperature is a temperature near the melting point at which the low melting point metal 12 melts. By this heating, the 12 low-melting point metal layers of the facing connecting portions of the laminated sheet coil 2 are melted, and the facing connecting portions are electrically connected and conducted by the low-melting point metal. Further, the adhesive 14 is melted by the heating, and then is thermally cured to bond the sheet coils together.

[0042] At this time, when a resin composition obtained by applying the curing agent or the like to the epoxy resin is used as the insulating material 10, the insulating film serving as the insulating material can withstand the melting temperature of the low melting point metal. It was confirmed that the insulating film itself maintained its insulating state well. In addition, this insulating film did not react with the low melting point metal and the low melting point metal flowed out. Furthermore, since this insulating film has little thermal expansion, it is favorable that the form of the sheet coil laminated by heat treatment is not affected.

After cooling, the adhesive 14 is cured to bond the sheet coils 2 together, and the connecting portions 8 of the overlapping sheet coils are electrically connected by the low melting point metal 12. As a result, the sheet coils are spirally connected, and a 15-turn laminated coil 1 is formed as a whole. Further, an insulating film is applied around the laminated coil 1 with epoxy resin, insulating tape, or the like.

Then, as shown in FIG. 4, a core material 18 such as a magnetic material core is passed through the rectangular hollow portion of the laminated coil 1. The core material includes steel, ferrite, cobalt, Kel etc. can be used. Next, a resin mold material 20 is coated around the laminated coil 1 and the core material 18 to a predetermined thickness. As the mold material 20, for example, an epoxy resin or the like mixed with iron powder and carbon powder is used. This iron powder induces magnetic flux as a magnetic material, and can effectively connect magnetic lines of force, increasing the coil inductance. In addition, the efficiency of coil cooling can be improved by the heat conduction effect of iron powder and carbon powder.

Further, as shown in FIG. 5, in the above-described resin mold, the bulging portion 22 is formed on the outer portion (on the opposite side of the center) of the laminated coil 1. Without this bulging portion, the thickness of the resin mold in the outer portion of the laminated coil 1 becomes narrow, and it is not preferable for the magnetic field lines to go around in the atmosphere. By providing the bulging portion 22 described above, the passage of the magnetic force lines 23 is widened so that the magnetic flux is guided to the inside of the molding material 20 and the molding material of the bulging portion 22, and the magnetic field lines are efficiently connected to reduce the coil inductance. Enhanced.

The choke coil 16 using the laminated coil 1 is completed by the above resin mold. As shown in FIG. 6, the choke coil 16 has a coil terminal portion 6 of the first-layer sheet coil and a coil terminal portion 6 of the fifteenth-layer sheet coil projecting upward. Is fixed to the substrate using a fastening tool such as a self-tapping screw. This choke coil is particularly useful as a coil for a power factor correction circuit that handles a large current, such as an air conditioner for air conditioning. The laminated coil 1 can also be used as a transformer coil.

[0047] Therefore, according to the laminated coil according to this embodiment, it is possible to manufacture by a consistent processing process such as a punching process, a printing process, a plating process, and a heating process, so that mass production can be easily performed. Cost can be reduced. In addition, since there is no base material, manufacturing without the need for a drilling process can be performed quickly, and the use of copper plates and multilayering are easy, reducing the effect of the skin effect, and a large number of hundreds of amps (amperes). Coils with current capacity can be easily made.

[0048] It should be noted that the sheet coils of the first to fifteenth layers shown in FIG. 1 are arranged on one copper plate, the insulating material 10 is applied to the entire copper plate, and the portion corresponding to the connection portion 8 is then applied. After removing the insulating material, or applying the insulating material 10 while leaving the connection portions 8, and then coating the low melting point metal 12 on each connection portion 8, punch out each sheet coil with a press cage, and then stack the layers. A laminated coil may be obtained through a process and an overheating process. [0049] Furthermore, there is a method of obtaining a plurality of laminated coils simultaneously. In this method, a plurality of first-layer sheet coils are arranged on the first copper plate, and the entire copper plate is coated with the insulating material 10 and the low-melting point metal 12 is coated as described above. Similarly, a plurality of second-layer sheet coils are arranged on the second copper plate so as to overlap with the first-layer sheet coils, respectively, and the insulating material 10 is applied thereto and the low melting point metal 12 is plated. Similarly, the third to fifteenth sheet coils are formed on the third and subsequent copper plates. Then, apply the adhesive to the first to fifteenth copper plates in the same way as in the laminating process and laminate them (or divide them several times), then punch out all the sheet coils at once. A plurality of laminated coils are obtained. At this time, delete any burrs remaining in the punched area.

[0050] Next, an embodiment in which a plurality of turns (here, four turns) of sheet-like coils are laminated to form a multi-turn laminated coil according to the second embodiment. FIG. 7 shows the sheet coil 32 constituting this laminated coil for each layer. These sheet coils 32 are composed of six sheets from the first layer to the sixth layer, each of which is a four-turn sheet coil. Each of the sheet coils 32 has a rectangular winding direction, a coil is formed spirally toward the inside (or outside) of the sheet, and both end portions are open.

[0051] Of the sheet coil 32, one end of each of the sheet coil 32 at the lowermost end (first layer) and the uppermost end (sixth layer) is formed with a coil terminal portion 36 in a state of protruding from a rectangular frame. The other end is formed with a connecting portion 38 that is electrically connected to another sheet coil. The sheet coils 32 from the second layer to the fifth layer are connected to other sheet coils on the surface portion near the end on one end side and on the back surface near the end on the other end side, respectively. The connecting portion 3 8 is formed. Each sheet coil 32 is formed with a connecting portion 38 so that the connecting portions near one end overlap each other and the winding direction is the same when the connecting portions are made conductive. .

[0052] The sheet coil 32 is, for example, sequentially stacked from the bottom to the first layer, the second layer, and the third layer. At this time, the connecting portions of the sheet coils 32 overlapping each other are arranged so as to face each other. If these are electrically connected and made conductive, a coil having 24 turns (= 4 × 6) is obtained.

[0053] The material used for the manufacturing process and insulation of the laminated coil of this form is the above laminated coil. This is basically the same as in case of mail 1. First, the sheet coils from the first layer to the sixth layer are manufactured by a stamping process using a press. In this process, each sheet coil is made by punching a copper plate.

As shown in FIG. 8, in the printing process, the insulating material 10 is printed on both surfaces of each sheet coil to a predetermined thickness to form an insulating film. After applying the insulating film, the insulating film that also serves as the insulating material on the surface of the connecting portion 38 of each sheet coil 32 is removed by the technique such as the etching process.

[0055] In the next plating step, the low-melting-point metal 12 is applied to the conductive connection portion 38 of the sheet coil from which the insulating film has been removed by a plating process. Next, the adhesive 14 is applied to one or both surfaces of the sheet coil 32, leaving the connection portion 38, and the sheet coils from the first layer to the sixth layer are laminated and bonded together.

[0056] Finally, the laminated sheet coil is put in a heating furnace or the like and heated at a predetermined temperature.

By this heating, the low melting point metal of each facing connection portion of the laminated sheet coil is melted, and the facing connection portions are electrically connected to each other by the layer of the low melting point metal. In addition, the adhesive 14 is melted by the heating, and is then thermally cured to bond the sheet coils together. After cooling, the adhesive is cured and the sheet coils are bonded together, and the connecting portions of the overlapping sheet coils are electrically connected by a low melting point metal, thereby forming a 24-turn laminated coil. Is done.

[0057] The periphery of the laminated coil is further coated with an insulating film by epoxy resin, insulating tape, or the like. Then, the core material made of a magnetic material is inserted into the rectangular hollow portion of the laminated coils. Next, the mold material 20 is coated around the coil and the iron core to perform the resin molding. Moreover, in the said resin mold, the bulging part is formed in the outer side (anti-center direction side) part of a coil. With this resin mold, a choke coil using a laminated coil is completed. This choke coil is also useful for power factor correction circuits such as air conditioners for air conditioning. The laminated coil can also be used as a transformer coil.

[0058] Therefore, the laminated coil according to this embodiment can be manufactured by consistent processing processes such as a punching process, a printing process, a plating process, and a heating process, as in the case of the laminated coil. Can be done easily and the cost can be reduced. Also on The sheet coil constituting the laminated coil has a large surface area and can reduce the influence of the skin effect, so that the current capacity can be increased.

Brief Description of Drawings

[0059] FIG. 1 is a diagram showing sheet coils from the first layer to the fifteenth layer constituting the laminated coil according to the embodiment of the present invention.

FIG. 2 is a diagram (a partial cross-sectional view taken along line AA in FIG. 1) showing a state where an insulating material is applied to the sheet coil and a low melting point metal is adhered to the sheet coil according to the embodiment.

FIG. 3 is a view showing a state in which an adhesive is applied to the sheet coils according to the embodiment and the sheet coils are bonded to each other.

FIG. 4 is a view showing a state in which a resin mold is applied to the laminated coil according to the embodiment.

FIG. 5 is a view showing a state in which a bulging portion is provided in a resin mold applied to the laminated coil according to the embodiment.

FIG. 6 is a view showing the laminated coil according to the embodiment, where (a) is a side view and (b) is a plan view.

FIG. 7 is a diagram showing sheet coils from the first layer to the sixth layer constituting a laminated coil according to another embodiment.

FIG. 8 is a diagram (partial cross section taken along line BB in FIG. 7) showing a state in which an insulating material is applied to a sheet coil and a low melting point metal or the like is attached to another embodiment.

FIG. 9 is a view showing a laminated coil according to a conventional example.

Explanation of symbols

[0060] 2 sheet coil

8 Connection

10 Insulation material

12 Low melting point metal

Claims

The scope of the claims

[1] Using a flat conductive sheet coil that is formed in a single turn or a plurality of turns in a spiral shape, and has a surface portion and a back surface portion in the vicinity of the end portion or a connection portion provided on one surface portion,

The sheet coil is coated with an insulating material on one or both sides of each sheet coil, and a low melting point metal is deposited on the connection part.

The sheet coil is configured so that the connecting portions of the overlapping sheet coils face each other and the winding direction is the same when the connecting portions are electrically connected to each other, and the overlapping is performed at the time of stacking. The sheet coils are stacked so that the insulating material is interposed between the sheet coils and the connecting portions face each other.

The entire laminated sheet coil was heated to melt the low melting point metal adhering to the connecting part, and the coiled part was formed by electrically connecting the connecting parts of the sheet coil. A method for producing a laminated coil, which is characterized.

[2] The laminated coil according to claim 1, wherein a thermosetting adhesive is interposed between the stacked sheet coils, and the sheet coils are bonded to each other by the calo heat. Production method.

[3] The insulating material according to claim 1 or 2, wherein the insulating material is an epoxy resin having a 2 to 4 oxysilane ring with a 2 to 4 base acid anhydride as a curing agent. A manufacturing method of laminated coil.

[4] The method for manufacturing a laminated coil according to claim 1 or 2, wherein an epoxy resin having a 2 to 4 oxysilane ring using imidazoles as a curing agent is used as the insulating material. .

[5] The insulating material according to claim 1 or 2, wherein an epoxy resin having 2 to 4 oxysilane rings having a polyimide resin or polyamideimide resin as a curing agent is used as the insulating material. The manufacturing method of the laminated coil of mounting.

6. The method for manufacturing a laminated coil according to any one of claims 1 to 5, wherein tin, lead or solder is used as the low melting point metal.

7. The method for manufacturing a laminated coil according to any one of claims 1 to 6, wherein the sheet coil is formed by punching a copper plate into a rectangular loop shape. 8. The method for manufacturing a laminated coil according to claim 7, wherein after the heating, the laminated sheet coil is covered with a molding material mixed with iron powder. A laminated coil produced by the method for producing a laminated coil according to any one of claims 1 to 8.