JP4685952B2 - Winding integrated mold coil and method for manufacturing winding integrated mold coil - Google Patents

Description

  The present invention relates to a winding integrated mold coil and a method for manufacturing a winding integrated mold coil.

  2. Description of the Related Art Conventionally, a molded coil that is wound around a core such as a ferrite core and sealed with a magnetic molding material has been widely used. Conventional mold coil molding methods are performed using transfer molding (transfer molding) or injection molding (injection molding). Conventionally, a coil having good characteristics (particularly a power inductor) could not be made without a magnetic core such as a ferrite core.

  Therefore, the applicant has proposed a wound-integrated mold coil having good characteristics by plastic molding, which has been impossible in the past, using the method and materials of Japanese Patent Application No. 2008-170161 filed earlier.

  There is also a winding integrated mold coil in which a granulated powder made of a binder and a magnetic powder and a winding are integrated by powder compression molding. (See Patent Document 1)

  There is a multilayer inductor in which a winding portion is formed by printing or the like with respect to these winding integrated coils. An electrode pattern that circulates in an unfired sheet containing magnetic powder, etc. is formed on each sheet by printing, etc., and after lamination and pressure integration between each sheet, the magnetic powder and metal conductor powder are sintered by firing, The conductors between the layers and between the layers are electrically joined to form an integrated coil. Generally, a large number of products are produced at once by cutting a plurality of aggregates after laminating.

  There is also a patent relating to a method of manufacturing a high-frequency coil in which a plurality of windings are molded in resin and cut into individual coils. (See Patent Document 2)

  The applicant has proposed a method for manufacturing a molded coil using a support pin and a positioning pin in Japanese Patent Application No. 2008-323400 and the like. Although the present application can embed the mold position of the air-core coil with high accuracy and is advantageous for small parts, a manufacturing method that is superior in terms of cost is required.

Further, in Japanese Patent Application No. 2008-170161, the applicant uses a plastic compression molding method to selectively eject the resin in the mold resin in which the magnetic powder is dispersed to the outside of the mold coil, thereby producing a mold coil with improved inductance. Proposed method.

JP 2007-49073 A JP 2005-116708 A

  In general, a coil coil with integrated winding uses a wire material compared to a laminated inductor, so the direct current resistance value is low, which is advantageous for power inductors for power applications. However, it takes time to join the coil end part. . In addition, since the coil terminal part and the external electrode part need to be exposed after molding, it is common to embed the coil terminal part or the external electrode part on the side surface of the molding die or in the vicinity thereof, but to a predetermined position in the mold. It is necessary to make a frame and a highly accurate apparatus for installation of the apparatus, and further, it is necessary to manufacture a plurality of collective molded bodies that are continuous on a non-exposed surface or an individualized molded body connected by a gate, etc. Compared to the multilayer inductor method, the number of steps is small, and the number of processing steps, tool costs such as molds, and the like are increased, which is disadvantageous in terms of cost.

In particular, a metal frame used for installing a coil member or the like is wasteful of materials such as a punching guide portion and a punching margin portion and is expensive because the plate material is plated or punched.

By the way, in forming the external electrode of the multilayer inductor, the terminal cross-sectional electrode and the external electrode are joined by applying and sintering a paste in which conductive powder is dispersed on the terminal cross-section exposed after cutting the assembly, and sintering. Therefore, there is no need to connect the wire to the metal external electrode by welding or the like, and the smaller the size, the less the welding space, the higher the machine accuracy and the higher the cost, and the cost of terminal welding joining becomes unnecessary. . The terminal cross-section electrode formed by cutting or the like and the external electrode are bonded to each other by metal bonding by sintering, and therefore have a certain low resistance.

Since the coil integrated with a coil is molded with a molding material containing a large amount of resin, external electrodes cannot be formed by sintering. Examples of the electrode material include a conductive resin. The conductive resin is a resin compound material having conductivity by applying a paste-like liquid in which a resin and a conductive filler are dispersed, followed by drying and curing. In addition, since no frame is required, it is very advantageous in terms of cost.

However, since the conductive resin external electrode and the coil terminal are joined not by metal bonding but by a conductive filler, the joint resistance is very high in a similar terminal bonding structure (general) In particular, the specific resistance of conductive resin is several tens of times higher than the specific resistance of conductors).

In order to reduce the contact resistance, the contact area may be increased. In order to increase the contact area, the winding may be cut and joined at an angle, or it may be joined at the side of the winding, but it may be difficult to ensure a sufficient contact area for the oblique cutting. In order to expose, it is not easy to ensure uniformity in terms of man-hours, installation technology, and cutting technology, and the cost increases.

In other words, if the terminal cross section exposed by cutting or the like is joined to the external electrode, and the joint resistance can be easily reduced, a plurality of winding integrated coils can be manufactured in large quantities with relatively small equipment.

If a large number of coils can be produced, the number of steps per piece can be reduced as in the case of a multilayer inductor, and a very inexpensive wound integrated mold coil can be manufactured.

Conventional molds made of a molding material such as resin or a mixture of resin and inorganic powder are difficult to embed the winding uniformly at the intended position, and the magnetic resistance changes due to the variation of the winding position. Inductance, DC superimposition, and heat generation variation occur. In particular, a molding material whose magnetic material volume ratio exceeds 60 vol% has a certain degree of viscosity at the time of molding. In transfer molding or the like, the winding may be pushed out and deformed by the force of the resin flow, and the position is stabilized. Was not easy.

Japanese Patent Application No. 2008-323400 and the like filed earlier describe a method of manufacturing a molded coil using the support pin and the positioning pin. The supporting pin and the positioning pin that move independently can determine the embedment position of the air-core coil with high precision by machining, and are advantageous for small parts, but also the number of molds, mold cost, and processing man-hours A superior manufacturing method is desired.

In addition, the method proposed in Japanese Patent Application No. 2008-170161 increases the inductance, that is, selectively extrudes the resin in the magnetic material-dispersed mold resin in the process of forming the slit or the gap between the die mold and the punch mold. When the method of increasing the relative magnetic permeability by increasing the content of the inner magnetic powder is used in forming an assembly in which a plurality of windings are simultaneously formed and individually separated by cutting or the like, the gap is formed in the vicinity of the end face, etc. For this reason, there is a difference in the magnetic powder content between the end face and the center, and the inductance is likely to vary. Therefore, it is necessary to form a uniform mechanism and suppress variations in inductance.

Further, when cutting the coiled coil in which the metallic powder magnetic material is dispersed, the surface of the resin or the metallic powder magnetic material can be obtained by using a rotary diamond blade having a hardness higher than that of the metallic powder magnetic material. Insulating properties obtained by the insulating film processed in this manner are deteriorated by scratches on the surface, metal elongation and deformation, and rust is generated from the cut surface.

In the molded coil according to the present invention, the winding 1 is sealed with a mold resin, and at least a part of the winding 1 end is provided with a conductor addition portion 2 having a large cross section. The winding 1 and the conductor addition portion 2 are formed. Is electrically joined, and in the molded coil 6 in which at least a part of the conductor addition part 2 is embedded in the molded coil molded body 3, at least a part of the conductor addition part 2 is electrically joined to the external electrode 7. It is characterized by.

  Further, the conductor addition portion 2 is a conductive resin made of a conductor powder and a resin.

A method for producing a coiled integral mold coil according to the present invention uses a magnetic molding material mainly composed of a magnetic powder and a resin, and a plurality of plastic compression moldings in which at least a part of the resin is compression molded in a molten state. In the method of manufacturing a molded coil in which a single winding 1 is embedded, the molding material is divided into two or more of the upper molding material 13 or the lower molding material 10, and at least one of the molding materials is molded into a plate shape, After pressure-embedding at least a part of the coil member in a state where at least a part of the resin is melted in the molding material, the other material is supplied, and at least a part of the resin is pressure-molded in a molten state, After the winding 1 is completely embedded, the end of the winding 1 or the conductor addition portion 2 is exposed, and then the external electrode 7 to be electrically joined is formed.

The method for producing a coiled integral mold coil according to the present invention is obtained by applying melt pressure to at least a part of at least one of the lower molding material 10 and the lower molding mold 8 and between the upper molding material 13 and the molding punch mold 12. A sheet-like or sheet-like sheet 11 that absorbs a large amount of resin during molding is inserted.

In the method of manufacturing a coiled integral mold coil according to the present invention, at least one of the lower molding material 10 and the upper molding material 13 is formed into a plate shape by pressure molding a powder or granular magnetic molding material. It is characterized by

The method for manufacturing a winding-integrated mold coil according to the present invention is characterized in that the embedded winding 1 has a conductor addition portion 2.

The method for producing a wound integrated mold coil according to the present invention is characterized in that the magnetic molding material contains metal magnetic powder with a volume ratio of 65 vol% or more.

The method of manufacturing a coiled integral mold coil according to the present invention is particularly effective when the magnetic molding material contains metal magnetic powder by cutting at least a part of the winding 1 end or the conductor addition portion 2. When exposed to the outside of the molded coil molded body 3, the resin is selectively separated in the resin or at the metal magnetic powder (including the metal magnetic powder processed surface) and the resin interface.

The method of manufacturing a coiled integrated mold coil according to the present invention is such that when individually separating from a plurality of molded bodies, it is divided by pressing, separated by the pressure of air and the impact of powder accelerated by air, water flow, etc. A method using any one of methods of separating by embrittlement or combustion of only a resin by heating with a laser beam or the like, or a method combining any of the methods. To do.

  The winding integrated coil of the present invention has an external electrode 7 and increases the contact area by joining the additional conductor exposed portion 4 formed by forming the conductor additional portion 2 at the end of the winding 1 and the outer electrode 7. Thus, the junction resistance can be reduced and the junction reliability can be increased. This coil integrated with a wire can be manufactured by either plastic molding such as injection molding, transfer molding or compression molding, or a coil in which an air core coil is integrated by powder molding.

The method for producing a wound integrated mold coil according to the present invention is characterized in that a plurality of wound integrated coils can be efficiently molded. In particular, the embedding position accuracy of the winding to be embedded can be increased without requiring a complicated process, which is not only advantageous in terms of cost but also improves characteristic variations and reliability.

  The method for manufacturing a coiled integral mold coil according to the present invention is to produce a molded coil 6 through a step of processing a magnetic mold resin into a plate shape by powder compression molding, so that the cutting margin and transfer molding when formed into a sheet are made. Costs can be reduced because there is no waste of materials such as runners.

  The resin blotting sheet 11 that absorbs a large amount of resin in the method for producing a coiled integral mold coil according to the present invention can increase the magnetic substance content in the molded coil molded body 3 and increase the inductance.

In the method for producing a coiled integral mold coil according to the present invention, the method of individually separating from a plurality of molded bodies is the interface between the resin or the surface of the resin and the metal magnetic powder (or the metal magnetic powder processed surface) and the resin. Can be selectively cut, so that deterioration of insulation is avoided and rust on the cut surface is also suppressed.

FIG. 1 is a perspective view showing a winding in which a conductor addition portion according to one embodiment of the present invention is formed. FIG. 2 is a transparent perspective view showing a molded coil molded body in which a winding wire according to one embodiment of the present invention is embedded. FIG. 3 is a perspective view showing a molded coil according to one embodiment of the present invention. FIG. 4 is a schematic transparent perspective view showing a mold and a lower molding material for illustrating an example of the production method of the present invention. FIG. 5 is a perspective view showing an assembly of windings partially embedded in the lower molding material for illustrating an example of the production method of the present invention.

Hereinafter, the winding integrated mold coil of this invention and the manufacturing method of a mold coil are demonstrated, referring an accompanying drawing.

The molded coil 6 of FIG. 3 is a winding integrated coil obtained by molding an air-core coil like the winding 1 of FIG. 1 with a magnetic molding material, and the outer electrode 7 of FIG. A conductive resin electrode or a plating electrode that can be bonded to the terminal can be used, but the effect is particularly high in the conductive resin external electrode, and will be described in the future with the conductive resin external electrode.

In the winding 1 shown in FIG. 1, it is preferable that the conductive wire has an insulating coating and has a self-bonding property. A wire having a self-bonding property is more advantageous in a wire having a small wire diameter or thickness, especially in a wire embedment process, a molding process, and the like, with less deformation and the like. Further, the outer and outer windings that start from the outside of the rectangular wire with good winding volume efficiency and end outside can advantageously reduce the DC resistance and increase the inductance and the DC superimposed current, and the winding 1 in FIG. Although shown with outer and outer windings, any winding or winding method can be used.

Both ends of the winding 1 are cut slightly larger than the molded coil molded body so as to be exposed on either surface of the molded coil molded body. The cross section of the molded body is higher in the bonding reliability when the winding exposed portion 5 in FIG. 2 is formed, but only when the additional conductor exposed portion 4 in FIG. You may cut | disconnect to the magnitude | size which exposes.

Both ends of the winding 1 are mechanically or thermally removed from the insulation coating, and a conductor for increasing the cross section of the winding 1 is added in the vicinity of the removed portion. The added conductor may be a molten metal such as solder, but the conductive resin is highly reliable for heat from adhesiveness to external electrodes and heat cycles, so the amount and position of the addition can be easily set in the future. A description will be given using conductive resin including examples.

The conductor addition portion 2 made of a conductive resin added to both ends of the winding 1 is formed by coating, drying, and curing. The conductive resin is a paste in which a conductive powder such as silver or copper is dispersed in the resin. The contact resistance can be reduced when the specific resistance is as small as possible, and the same type of resin as the external electrode 7 should be used. High thermal reliability. As a coating method, the terminal is immersed in a conductive resin paste, or is coated with a dispenser, a brush or the like. When the application shape is a dumpling, the area of the additional conductor exposed portion 4 is increased, and the connection resistance is preferably reduced.

The winding 7 is integrated with the magnetic mold forming material. The magnetic molding material is mainly composed of a magnetic powder such as metal or ferrite, a thermosetting resin such as epoxy, or a thermoplastic resin such as nylon. The molding method can be carried out by injection molding, transfer molding, compression molding, which is a plastic molding method, or by compacting, which is a powder molding method.

The molded coil molded body 3 performs deburring and chamfering with a barrel or the like. The external electrode 7 can be applied by setting a large number of molded coil molded bodies in a jig made of silicon rubber or the like and simultaneously dipping in a conductive resin. Usually, one side is applied and dried, and the other is formed by application, drying and curing.

Although not shown in the drawing, the surface of the conductive resin external electrode 7 is usually plated with nickel, tin or the like to improve the wettability of solder or the like.

In the method for manufacturing a coiled integral mold coil according to the present invention, a lower molding material 10 made of magnetic powder and resin is placed in a cavity formed by the mold lower mold 8 and mold die 9 shown in FIG. After the wire is melted by heating, a part of the winding wire 1 (which may not have a conductor adding portion) is buried under pressure at a predetermined position to determine the embedding position. (The winding 1 may be embedded in the upper molding material 13)

By partially embedding the winding 1, the material flow is reduced in the melt compression molding process in which the next winding is completely embedded, and the winding position does not shift. In other words, if the winding is only placed, not only is there no binding force on the winding position, but there is a lot of mold resin flow to cover the winding, and the flow is not always uniform, so the winding position is Deviation, inductance and other characteristic variations occur. Therefore, it is ideal to embed until the burial depth is almost flat.

The embedding temperature is about 30-50 degrees higher than the resin melting temperature of the molding material, and the embedding temperature is too high. The embedded winding 1 is easy to move, and there is a concern that the thermosetting resin may be cured. On the other hand, if the temperature is too low, the embedding pressure increases and the winding tends to deform.

The lower molding material 10 is a magnetic mold resin molded in advance into a plate shape. Molding into a plate shape can be performed by punching out a sheet formed by an extrusion molding machine, etc., but punching whitening will occur and material loss will occur, especially when using a thermosetting resin for the material remaining in the equipment Since loss and cleaning require man-hours and cost increases, powder compression molding is preferable.

In powder compression molding, as in normal powder compression molding, a mold made up of a lower punch, a die, and an upper punch is used, a powder material is placed in the cavity, and a predetermined amount of plate thickness is produced by the position and grinding of the lower punch. The temperature of the die and the lower mold is preferably about the resin melting temperature ± 10 degrees. If the mold temperature is higher, the molding pressure can be reduced. However, if the mold temperature is too high, the material adhering to the wall surface of the die and the materials stick to each other during grinding, and the amount of material in the cavity is not stable. Further, the upper punch is more stable when the temperature is lower than that of the lower punch and the die, with less material adhering to the upper punch.

The size of the die is set slightly smaller than that of the molding die 9. If it is too large, it will not enter the mold die 9, and if it is too small, a flow of the molding material may occur during melt compression molding, and the embedding position may shift. The same mold may be used as the powder mold and the mold shown in FIG. 4, and the plate-shaped powder molding material may be removed from the mold without changing the heating temperature.

The upper molding material 13 may be supplied in a powder state. However, it is better that the upper molding material 13 is produced by powder compression molding like the lower molding material 10 in order to reduce entrainment of bubbles in the molded coil molding 3.

The lower molding material 10, the winding 1 and the upper molding material 13 are integrated by compressing the upper molding material 13 so as to cover the lower molding material 10 in which the winding 1 is embedded. The temperature at this time is preferably compressed from the temperature at which the winding is embedded to increase the temperature. Since the position of the embedded winding may shift when integrated compression is performed at a high temperature, after the molding materials are brought into close contact with each other at a predetermined pressure, the temperature and pressure are further increased. When using a thermosetting resin, the curing time can be shortened and the cost can be reduced. Further, the integration can be performed under reduced pressure, and bubbles can be prevented from being entrained, resulting in improved characteristic variation and reliability.

As the resin blotting sheet 11 that selectively sucks only the resin, a stainless mesh or paper having an opening smaller than the magnetic particle diameter can be used. Ease of sucking, selectivity, and amount of sucking are determined by the relationship between the size and thickness of the openings and the particle size of the magnetic powder. It is preferable to put a plurality of sheets between the lower molding material 8 and the lower molding material 10 and between the upper molding material 13 and the molding punch die 12 as necessary. Further, a metallic mesh or the like can be regenerated and used a plurality of times, for example, by decomposing the resin by heating. By selectively sucking out only the resin, the content of the magnetic powder in the molded coil can be increased, and the inductance can be increased.

In the magnetic powder-dispersed mold material, the main magnetic powder is preferably a metal magnetic material, and the powder content is preferably 65 vol% or more by volume ratio. The metal magnetic material is preferably a material having a high saturation magnetic flux density.

A typical power inductor combines a drum-shaped core made of ferrite material and a ring-shaped core, winds around the drum-shaped core, creates an air gap in the gap between the ring and drum, and has an equivalent ratio. The permeability is about 20 to 40. This is because, if the inductance is the same, the DC superposition characteristics with a larger number of windings are better, and therefore the equivalent relative permeability is reduced depending on the size of the gap between the ring and the drum and the number of windings is increased. On the other hand, if the number of turns is increased, the DC resistance value will increase by the distance of the conducting wire, and if the conductor diameter (cross-sectional area) is increased, the volume and weight of the coil will increase and the performance will decrease. Permeability is required.

By the way, if it is a magnetic powder dispersion resin and the relative permeability is 20-40, an inductance can be obtained with an equivalent number of turns with a coil integrated with a winding. Furthermore, if the metallic magnetic material has a saturation magnetic flux density much higher than that of the ferrite material, a large saturation current can be flowed, so that the direct current superimposition characteristic is improved several times. However, in order to realize a relative permeability of 20 or more, it is necessary that the magnetic powder contains 65 vol% or more by volume ratio.

In addition, the viscosity is high above the volume ratio, and there are many deformations and other problems in winding in transfer molding and the like. However, in the compression molding method of the present invention, the amount of movement of the mold resin is small, so that deformation and the like hardly occur and embedded. The force for restraining the coil 1 is increased, and the buried position shift hardly occurs. On the other hand, when the volume ratio is lower than 65 vol%, the viscosity of the kneaded resin becomes too low, so that the winding position is shifted by its own weight or the like, and the characteristic variation becomes remarkable.

In the present invention, it is necessary to form the additional conductor exposed portion 4 or the winding exposed portion 5 by cutting or the like. If a plurality of molded coil assemblies are obtained by molding and then cutting a plurality of coil assemblies, mass production is possible at the same time as a multilayer inductor, which reduces the number of processing steps per unit and is advantageous in terms of cost. become.

However, when a molded body in which metal powder is dispersed is cut with a rotary blade coated with diamond, the metal powder itself is cut to cause elongation of the metal, and the insulating film processed on the surface of the metal powder is also removed. Therefore, not only the insulating properties deteriorate, but also the metal surface covered with the resin or the like is exposed, so that rust is easily generated. In particular, the deterioration of the insulating property of the cut surface (surface where voltage is applied) that is not the terminal exposed surface may lead to a decrease in inductance.

Therefore, in the present invention, the molded coil molded body 3 is selectively separated in the resin of the mold resin or at the interface between the resin and the metal powder so as not to be cut in the metal-based powder and to generate metal elongation. As the method, the separation is performed by previously dividing the slit or the like into the lower molding material 10 or the upper molding material 13 at the time of compression molding or the like, or the powder ejected by sandblasting is lower than the hardness of the metal powder material Separation without scratching the metal using a method, softening the resin at a high temperature and then separating with a push blade, or using a high-pressure water stream, or selectively decomposing or degrading the resin alone For example, there is a method of separation by laser light, and combinations thereof may be used.

  The shape of the molded coil 5 shown in FIG. 3 manufactured in this example is length * width * thickness of 2.5 mm * 2.0 mm * 1.2 mm.

92 wt% of amorphous magnetic powder having an average particle size of 30 μm and 8 wt% of an epoxy resin mixture in which novolak type epoxy resin and phenol novolak type resin are mixed in an equivalent amount are mixed at 110 ° C. for 40 minutes in a kneader, and then TPP is added to the epoxy resin mixture. .05 wt% was added, mixed for 3 minutes, cooled and pulverized, and adjusted to a powder of 0 or 5 mm or less.

The winding 7 of FIG. 1 was prepared. The wire is a self-bonding rectangular wire having a width of 0.25 mm and a thickness of 0.06 mm, wound 12 turns by winding outside and outside around a winding core 1 mmΦ, and the distance between the ends of the winding ends is 2,5 mm, which is the length of the mold coil. It cut | disconnected so that it might become 2,6 mm larger than 1 mm. About 0.6 mm double-sided insulation coating on one side of the terminal part was scraped off with a single blade, and the part shaved in a conductive resin composed of epoxy resin and silver was immersed in one terminal, pulled up as it was, and dried. Similarly, the other terminal was also applied and dried and cured at 150 ° C. for 1 hour to form a conductive resin addition portion 6.

Next, the lower punch die and the die die are preheated to 90 degrees, which is 10 degrees higher than the resin melting temperature of 80 degrees, and the position of the lower punch mold is set so that the powder material becomes a predetermined amount when the upper surface of the die mold is scraped. It was adjusted. Preheat the upper punch temperature to 75 ° C, put the powder material in the cavity surrounded by the lower punch and the die, cut through the die surface, and pressurize the upper punch die at a pressure of about 1 t / cm2, The lower molding material was made. A plate-like molded body having a width and a length 0.5 mm smaller than that of the molding die 9 and a thickness of 0.7 mm was manufactured. Also, the upper molding material was manufactured in the same manner so that only the thickness was 0.5 mm.

Next, the molding die 9 was placed on the lower mold 8 of FIG. A stainless steel mesh opening 0, 03 mm, which is a resin blotting sheet 11 cut slightly smaller than the mold, was placed in a mold die 9 and preheated at 110 degrees. After sufficiently preheating, the lower molding material was placed on the mesh in the die and preheated for 10 seconds.

The winding 1 was embedded at a predetermined position in FIG. The embedding depth was set to about 0.3 mm, which is a little deeper than the wire width.

Next, as shown in FIG. 5, the upper molding material was put into the mold of FIG. 4, and the pre-heated mold punch die 12 was put into the mold die 9. The mold is placed in a vacuum vessel and the pressure is reduced to 70 mmHg or less, and then the mold punch is pressed at a pressure of 100 kg / cm 2. After 10 seconds, the mold temperature is raised to 160 ° C. and left at a pressure of 300 kg / cm 2 for 15 minutes to cure. It was.

The cured molded body was taken out from the mold, and after the resin blotting sheet 11 was peeled off, the molded molded body 3 was cut into a molded coil molded body 3 in FIG. As a cutting method, a slit was made with a laser marker to a predetermined size, and the slit was bent and separated along the line.

Put the separated molded coil molded body into a centrifuge barrel and take a burr and corner, then apply the conductive resin made of epoxy resin and silver powder to the surface with the conductive resin cross-section exposed part 4 one side at a time, and dry at 100 degrees 5 minutes did. After completion of the double-sided drying, the resin was cured at 150 ° C. for 1 h to obtain a molded coil 6 in FIG.

Furthermore, the mold coil 6 was made to have a thickness of 3 μm and 6 μm, respectively, with nickel and tin plating in a neutral bath.

  In the coiled integrally molded mold coil, terminal bonding can be performed on the side of the molded body, which is advantageous in terms of material cost and man-hours, the contact resistance can be reduced without using a complicated molding method, and the structure is excellent in mass productivity.

In the winding integrated mold coil, the burying position of the winding can be manufactured without using a mold having a complicated structure or a complicated process.

Furthermore, it has a mechanism for selectively sucking out only the resin during pressure molding, and a high inductance can be obtained with a simple mechanism, which is advantageous in terms of cost and performance.

By the separation method that limits the cut and separated portions, it is possible to manufacture a coiled integral mold coil with high reliability by suppressing the occurrence of insulation failure and rust peculiar to the mold coil using the metal magnetic material.

DESCRIPTION OF SYMBOLS 1 Winding 2 Conductor addition part 3 Mold coil molding 4 Additional conductor exposure part 5 Winding exposure part 6 Mold coil 7 External electrode 8 Molding lower mold | type 9 Molding die type | mold 10 Lower molding material 11 Resin blotting sheet 12 Molding punch Mold 13 Upper molding material

Claims (3)

  In a method for producing a molded coil in which a plurality of coil members are embedded by plastic compression molding in which a magnetic molding material mainly composed of magnetic powder and resin is used, and at least a part of the resin is compression molded in a molten state, the molding material Is divided into two or more, and at least one of the molding material is molded into a plate shape, and at least a part of the coil member is pressure-embedded in a state where at least a part of the resin is melted in the molded molding material. Furthermore, after supplying the material and press-molding at least a part of the resin in a molten state, and embedding the coil member almost completely, the coil member terminal was exposed, and the external electrode to be electrically joined was formed. A method of selectively sucking molten resin in at least a part between a mold to be compressed and a molding material. Method for producing a molded coil, characterized in that it placed a sheet or plate to. The method for manufacturing a molded coil according to claim 1, wherein a conductor having a large cross section is formed on at least a part of the end of the coil member. When the coil member terminal or the conductor forming portion embedded in the mold is separated and exposed to the outside, the resin in the molded body or metal magnetic powder (including the surface processed with metal magnetic powder) and resin are selectively used. The method for producing a molded coil according to claim 1, wherein the molded coil is separated at an interface.

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