JP2004241536A - Transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer that can suppress the deterioration of its reliability even when mold forming is performed on the outer packaging section of a laminated coil in which the height positions of a coil and the front end of a lead are made different from each other. <P>SOLUTION: In the lead 25 of a primary coil 26, a bent section 35 which is bent in the outer packaging section 30 is formed. The lead 25 having the bent section 35 is disposed so that the height position of its front end 36 may become different from that of the coil coupled with the lead 25 having the bent section 35. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transformer used for various electronic devices and the like.
[0002]
[Prior art]
Hereinafter, a conventional transformer will be described with reference to the drawings.
[0003]
6 is a cross-sectional view of a conventional transformer, FIG. 7 is an exploded perspective view of a laminated coil part as the essential part, FIG. 8 is a perspective view of the laminated coil part and the mold as the essential part, and FIG. FIG. 10 is a perspective view, and FIG. 10 is an enlarged view of a portion A in FIG.
[0004]
6 to 10, 1 is a closed magnetic circuit core, 2 is a medium magnetic leg of the closed magnetic circuit core 1, 3 is an outer magnetic leg of the closed magnetic circuit core 1, 4 is a primary coil, 5 is a secondary coil, 6 is an insulator. , 7 is a laminated coil portion, 8 is a lead portion of the primary coil 4 and the secondary coil 5, 9 is an upper mold portion of a mold, 10 is a lower mold portion of the mold, and 11 is a lower mold portion of the mold. The receiving part of the lead-out lead part 8 in the part 10, 12 is the exterior part of the laminated coil part 7, 13 is the molded coil part, a is the height position of the primary coil 4, b is the height of the tip part 15 of the lead-out lead part 8. Indicates the position.
[0005]
In the figure, in the conventional transformer, a primary coil 4 and a secondary coil 5 are laminated via an insulator 6 to form a laminated coil section 7.
[0006]
Then, the outer coil portion 12 is molded by molding the laminated coil portion 7 with the upper mold portion 9 of the mold and the lower mold portion 10 of the mold to form the mold coil portion 13, and the middle magnetic leg 2 of the closed magnetic circuit core 1 is formed. Was incorporated in the molded coil unit 13 to constitute a transformer.
[0007]
As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
[0008]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 05-36530
[Problems to be solved by the invention]
In the above-mentioned conventional configuration, the height position b at which the tip of the lead-out lead portion 8 is pulled out is determined by the height position c of the receiving portion 11 of the lead-out lead portion 8 in the lower die portion 10 of the mold. The height position of the stacking position a of the subsequent primary coil and the height position b of the tip end of the lead-out lead portion 8 were different from each other.
[0010]
For this reason, as shown in FIG. 10, the extraction lead 8 is deformed inside the molded coil section 13, and the insulator 6 between the primary coil 4 and the secondary coil 5 is separated by the extraction lead 8 from the secondary coil 5. Was pressed against the end corners 14 of each of them, and stress was applied to the end corners 14 to easily cause deterioration.
[0011]
Therefore, the dielectric strength between the primary coil 4 and the secondary coil 5 is reduced, dielectric breakdown is likely to occur, and the reliability may be reduced.
[0012]
Further, since the draw-out lead portion 8 is forcibly deformed by the molds 9 and 10, deformation stress remains in the mold coil portion 13. When the transformer is mounted on the printed circuit board by reflow soldering in a reflow solder tank. However, there is a problem that the exterior part 12 is heated to a high temperature due to heating during reflow soldering, the strength is reduced, and deformation or cracks are easily generated due to the stress remaining in the molded coil part 13, and the reliability is deteriorated. Had.
[0013]
The present invention solves the above-mentioned conventional problems. Even if molding is applied to the exterior portion of a laminated coil portion where the height position of the coil portion and the height position of the leading end of the lead-out portion are different, the reliability is improved. An object of the present invention is to provide a transformer in which deterioration is suppressed.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration.
[0015]
The invention according to claim 1 of the present invention particularly provides a lead lead portion having at least one primary coil and a secondary coil formed with a bent portion bent inside the exterior portion on the lead lead portion. In this configuration, the height position of the distal end portion and the height position of the coil portion coupled to the extraction lead portion having the bent portion are arranged at different heights.
[0016]
With the above configuration, since the height position of the distal end portion of the lead portion forming the bent portion and the height position of the coil portion coupled to the lead portion forming the bent portion are arranged at different heights, Molding can be performed without deforming the extraction lead, the insulator between the primary coil and the secondary coil is not pressed by the extraction lead, and the stress of the insulator disappears, and the connection between the primary coil and the secondary coil is reduced. The dielectric strength between them can be stabilized.
[0017]
In addition, since the deformation stress is eliminated from the inside of the molded coil portion, no deformation or crack is generated in the exterior portion even when reflow soldering is performed, so that the life can be extended.
[0018]
The invention described in claim 2 of the present invention is particularly configured such that a primary coil and a secondary coil are stacked via a sheet-shaped insulator.
[0019]
With the above configuration, the thickness of the transformer can be reduced by reducing the thickness of the insulator.
[0020]
The invention described in claim 3 of the present invention is particularly configured such that the exterior part is made of a thermoplastic synthetic resin.
[0021]
According to the above configuration, since the exterior portion is made of a thermoplastic resin, the thermoplastic resin can be reused, so that member costs can be reduced.
[0022]
The invention described in claim 4 of the present invention is particularly configured such that the exterior portion is made of a liquid crystal polymer made of an aromatic polyester resin.
[0023]
With the above configuration, the exterior portion is made of a liquid crystal polymer made of an aromatic polyester resin. Therefore, the liquid crystal polymer made of an aromatic polyester resin has good fluidity and can shorten the molding time, so that the production cost can be reduced.
[0024]
The invention described in claim 5 of the present invention has a configuration in which one of the primary coil and the secondary coil is formed of a thin plate conductor in a flat plate shape, and the other is formed by winding an electric wire with an insulating coating.
[0025]
With the above configuration, since the wire with the insulating coating is wound, the number of turns can be easily changed, and the degree of freedom in designing the laminated coil portion can be improved.
[0026]
The invention according to claim 6 of the present invention is particularly configured such that the electric wire with an insulating coating is an electric wire with an insulating coating having a rectangular cross section.
[0027]
According to the above configuration, since the electric wire with the insulating coating having a rectangular cross section is used, the space factor of the winding can be increased, the coil resistance can be reduced, and the loss can be reduced.
[0028]
The invention according to claim 7 of the present invention is particularly configured such that the electric wire with an insulating coating is an electric wire with an insulating coating having a circular cross section.
[0029]
With the above configuration, a wire with an insulating coating having a general circular cross-sectional shape is used, so that the cost of members can be reduced, and the speed of winding work can be increased to improve workability and productivity. can do.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
A transformer according to an embodiment of the present invention will be described with reference to FIGS.
[0031]
FIG. 1 is a cross-sectional view of a transformer according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a laminated coil part as the main part, and FIG. 3 is a perspective view of the laminated coil part and a mold as the main part. FIG. 4 is an exploded perspective view of the same, and FIG. 5 is an enlarged view of a bent portion of a lead lead portion, which is an essential part of the same.
[0032]
1 to 5, a transformer according to an embodiment of the present invention is arranged on a closed magnetic path core 23 having a middle magnetic leg 21 and an outer magnetic leg 22, and on the outer periphery of the middle magnetic leg 21 of the closed magnetic path core 23. A primary coil 26 and a secondary coil 27 in which a coil portion 24 and a lead lead portion 25 coupled to both ends of the coil portion 24 are formed in a plate shape by a thin plate conductor, and a primary coil 26 and a secondary coil 27 are formed in a sheet shape. The laminated coil portion 29 laminated via the insulator 28 and the laminated coil portion 29 except for the tip of the lead-out lead portion 25 are molded with a liquid crystal polymer of an aromatic polyester resin which is an insulating resin and a thermoplastic resin. A sealed exterior part 30 is provided.
[0033]
At this time, a bent portion 35 bent inside the exterior portion 30 is formed in the lead lead portion 25 of the primary coil 26, and the height position b of the distal end portion 36 of the lead lead portion 25 having the bent portion 35 and the bent portion 35 Are arranged at different heights from the height position a of the coil portion 24 coupled to the lead lead portion 25 formed with.
[0034]
Further, the height positions of the lead-out lead portion 25 of the primary coil 26 and the lead-out lead portion 25 of the secondary coil 27 are arranged in accordance with the position of the receiving portion 34 of the lower mold portion 32 of the mold.
[0035]
Then, the outer coil portion 30 is formed by molding the laminated coil portion 29 with the upper mold portion 31 of the mold die and the lower mold portion 32 of the mold die to form a mold coil portion 33, and the middle magnetic leg 21 of the closed magnetic circuit core 23 is formed. Is incorporated in the molded coil section 33 to constitute a transformer.
[0036]
The bent portion 35 of the lead 25 may be formed on the secondary coil 27, or may be formed on the primary coil 26 and the secondary coil 27.
[0037]
Further, the angle of the bent portion 35 does not need to be 90 degrees, and may be formed as shown in FIGS. 5 (a) and 5 (b).
[0038]
According to the embodiment of the present invention, the lead portion 25 of the primary coil 26 is formed with the bent portion 35 bent inside the exterior portion 30, and the distal end portion 36 of the lead portion 25 having the bent portion 35 is formed. Since the height position “b” and the height position “a” of the coil portion coupled to the lead-out lead portion 25 having the bent portion 35 are arranged at different heights, the leading end portion 36 of the lead-out lead portion 25 to be drawn out is different. The height position b and the height position c of the receiving portion 34 of the lead-out lead portion 25 in the lower mold portion 32 of the mold can be made equal, and the stress applied to the lead-out lead portion 25 due to molding is eliminated, thereby eliminating deformation. be able to.
[0039]
As a result, the sheet-like insulator 28 between the primary coil 26 and the secondary coil 27 is not pressed by the extraction lead portion 25, and the stress of the sheet-like insulator 28 is eliminated, and the primary coil 26 and the secondary coil 27 The dielectric strength during the stabilization can be stabilized.
[0040]
Further, since the stress of the deformation of the lead-out lead portion 25 is eliminated from the inside of the molded coil portion 33, no deformation or crack is generated in the exterior portion 30 even by reflow soldering, so that the life can be extended.
[0041]
Further, by adjusting the size of the bent portion 35 formed on the lead-out lead portion 25, the height position of the tip end portion 36 of the lead-out lead portion 25 is adjusted to the height of the receiving portion 34 of the lower mold portion 32 of the mold. Even if the number of the primary coils 26 and the secondary coils 27 to be stacked is changed or the thicknesses of the primary coils 26 and the secondary coils 27 are changed, the upper mold portion 31 and the mold Can be shared without changing the lower mold part 32.
[0042]
Since the insulator interposed between the primary coil 26 and the secondary coil 27 is the sheet-like insulator 28, the transformer can be made thin.
[0043]
Further, since the exterior part 30 is formed of a liquid crystal polymer of an aromatic polyester resin which is an insulating resin and a thermoplastic resin, the thermoplastic resin can be reused, thereby reducing member costs.
[0044]
Since the exterior portion 30 is made of an aromatic polyester resin liquid crystal polymer, the aromatic polyester resin liquid crystal polymer has good fluidity and can shorten the molding time, so that the production cost can be reduced.
[0045]
Further, one of the primary coil 26 and the secondary coil 27 may be formed in a plate shape with a thin conductor, and the other may be wound with an electric wire with an insulating coating. Changes can be made easily, and the degree of freedom in designing the laminated coil portion 29 can be improved.
[0046]
The electric wire with an insulating coating may be an electric wire with an insulating coating having a rectangular cross section. By using an electric wire with an insulating coating having a rectangular cross section, the space factor of the winding can be increased, and the coil resistance can be increased. And the loss can be reduced.
[0047]
Furthermore, the electric wire with an insulating coating may be an electric wire with an insulating coating having a circular cross-sectional shape. Since it is used, the cost of the members can be reduced, and the speed of the winding operation can be increased, and the workability and productivity can be improved.
[0048]
【The invention's effect】
As described above, according to the present invention, at least one of the primary coil and the secondary coil is formed with the bent portion bent inside the exterior portion on the lead lead portion, and the height of the tip of the lead lead portion having the bent portion is formed. The height position and the height position of the coil portion coupled to the lead lead portion having the bent portion are arranged at different height positions.
[0049]
As a result, even if the exterior part of the laminated coil part is molded, the insulation between the primary coil and the secondary coil is prevented from being pulled out and pressed by the lead part, and the gap between the primary coil and the secondary coil is suppressed. The dielectric strength can be stabilized, the deformation stress can be eliminated from inside the molded coil part, and even if it is mounted by reflow soldering, the occurrence of deformation and cracks in the exterior part can be suppressed. A suppressed transformer can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a transformer according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a laminated coil part as the main part. FIG. 3 is a perspective view of a laminated coil part and a mold as the main part. FIG. 4 is an exploded perspective view of the same. FIG. 5A is an enlarged view showing another example of the bent portion as the main portion. FIG. 5B is an enlarged view showing another example of the bent portion as the main portion. FIG. 6 is a cross-sectional view of a conventional transformer. FIG. 7 is an exploded perspective view of a laminated coil part as the main part. FIG. 8 is a perspective view of a laminated coil part and a mold as the main part. FIG. 10 is an enlarged view of part A in FIG.
Reference Signs List 21 Medium magnetic leg 22 Outer magnetic leg 23 Closed magnetic path core 24 Coil portion 25 Leader lead portion 26 Primary coil 27 Secondary coil 28 Sheet-shaped insulator 29 Laminated coil portion 30 Exterior portion 31 Mold upper part 32 Mold metal Lower mold part 33 Mold coil part 34 Mold coil part Lower mold part receiving part 35 Mold part 36 Tip part a Stacking height position of primary coil b Height position c of primary coil lead-out tip part Height position of receiving part of lower part of mold coil part mold

Claims (7)

A closed magnetic circuit core having a middle magnetic leg and an outer magnetic leg, a coil portion disposed on the outer periphery of the middle magnetic leg of the closed magnetic circuit core, and a lead lead portion coupled to both ends of the coil portion are formed in a flat plate shape by a thin plate conductor. The primary coil and the secondary coil formed in the above, a laminated coil part in which the primary coil and the secondary coil are laminated via an insulator, and a laminated coil part excluding the leading end of the lead-out part are molded with an insulating resin. An exterior part molded and sealed is provided, and a bent part bent inside the exterior part is formed on at least one of the primary lead and the lead-out lead part of the secondary coil, and the bent part is formed. A transformer in which a height position of a leading end portion of the lead-out portion and a height position of the coil portion coupled to the lead-out portion forming the bent portion are arranged at different heights. The transformer according to claim 1, wherein the primary coil and the secondary coil are stacked via a sheet-shaped insulator. The transformer according to claim 1, wherein the exterior part is made of a thermoplastic synthetic resin. The transformer according to claim 3, wherein the exterior part is a liquid crystal polymer made of an aromatic polyester resin. 2. The transformer according to claim 1, wherein one of the primary coil and the secondary coil is formed of a thin plate conductor in a flat plate shape, and the other is formed by winding an electric wire with an insulating coating. The transformer according to claim 5, wherein the electric wire with the insulating coating is an electric wire with the insulating coating having a rectangular cross section. 6. The transformer according to claim 5, wherein the electric wire with an insulating coating is an electric wire with an insulating coating having a circular cross section.

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