JP2004349562A - Transformer and coil for transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a small-scaled transformer whose current capacity is large, and whose inductance is not varied. <P>SOLUTION: A primary coil board (61) is configured with a plane annular shape wherein a copper coil (91) and a synthetic resin film (95) are laminated while a discontinuous gap is partly formed, and the synthetic resin film (95) is laminated on the surface of the copper foil while the copper foil (91) in the neighboring parts of the both edge parts is excluded, and the copper foil (91) in the neighborhoods of the both edge parts is formed as connecting terminals (65, 67). The plurality of primary coil boards (61) are successively connected to each other by the connecting terminal parts (65, 67) so that a primary coil (80) having the plurality of number of times of winding can be formed. A copper board (40) is configured as a secondary coil with a plane annular shape whose inner diameter and external diameter are almost the same as those of the primary coil while a discontinuous gap is partially formed. The copper board (40) is interposed between insulating boards (31) configured with a plane annular shape while any discontinuous part is not formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transformer, and more particularly, to a transformer having a capacity of about one kilovolt amp to several kilovolt amps for supplying power to a load requiring a relatively large voltage and a relatively low voltage. It concerns a suitable transformer.
[0002]
[Prior art]
Conventionally, a transformer of about 1 kV to several kV is formed by winding a copper wire having an insulating coating on an iron core such as a silicon steel plate to form a primary coil or a secondary coil, and a secondary coil corresponding to the number of turns of the primary coil. The desired output voltage is formed with respect to the input voltage by the ratio of the number of turns.
[0003]
[Problems to be solved by the invention]
In a transformer in which a copper wire is wound around an iron core, even if the winding is performed carefully, the inductance may vary due to the bias of the winding.
[0004]
Further, in order to reduce the influence of variations in inductance, the number of turns of the copper wire may be increased, making it difficult to reduce the size and weight of the transformer.
[0005]
Further, a stray capacitance may be generated at the folded portion of the winding, and the frequency characteristics may be deteriorated.
[0006]
In a transformer in which a copper wire is wound many times, friction occurs between the windings due to vibration during use, and the insulation coating of the copper wire may be damaged.
[0007]
[Means for Solving the Problems]
The present invention relates to a flat annular flexible substrate in which a copper foil (91) and a synthetic resin film (95) are laminated and partially provided with a discontinuous gap, and the copper foil (91) in the vicinity of both ends. ), A large number of primary coil plates (61) are laminated on the surface of the copper foil, and the copper foil (91) near both ends is used as a connection terminal (65, 67). A primary coil (80) having a plurality of turns is formed by sequentially connecting and concentrically overlapping the terminal portions (65, 67) for connection. A copper plate (40) having a flat annular shape having an outer diameter and having a discontinuous gap in a part thereof is used as a secondary coil, and the copper plate (40) has an inner diameter and an outer diameter substantially the same as those of the primary coil (80). Sandwiched by an insulating plate (31) having a flat annular shape having a diameter and having no discontinuous portion And it forms a transformer with a.
[0008]
As described above, the copper coil (91) and the synthetic resin film (95) are laminated to form a primary coil by concentrically laminating a large number of flat-plate-shaped flexible substrates partially provided with discontinuous gaps. When winding the primary coil (80), it is possible to easily prevent the winding from being biased.
[0009]
And since the primary coil (80) is formed by connecting the copper foil (91) of a flat annular shape, the coil can be formed thin even if the current capacity is large.
[0010]
In addition, since the secondary coil uses a plate-shaped annular copper plate (40), the current capacity can be increased, and the secondary coil is sandwiched by the plate-shaped annular insulating plate (31), so that the secondary coil can be easily insulated. Can be done.
[0011]
According to the present invention, a primary coil (80) formed by connecting and laminating a large number of primary coil plates (61) having the same shape, and a plurality of copper plates (40) are stacked with an insulating plate (31) interposed therebetween, and Preferably, (40) is connected in series to form a secondary coil, and the primary coil (80) and the secondary coil are coaxially attached to the iron cores (12, 16).
[0012]
As described above, the primary coil (80) and the secondary coil are coaxial, and the thin primary coil (80) and the secondary coil of the copper plate (40) are overlapped to form a small-sized transformer having a reduced thickness. Can be.
The secondary coil is formed by stacking copper plates (40) having discontinuous portions, which are a plurality of secondary coil plates, with the insulating plate (31) interposed therebetween and connecting them in series, so that the number of turns of the secondary coil is reduced. It can be easily adjusted.
[0013]
The present invention also provides a flexible substrate in which a substantially annular copper foil (91) having a discontinuous portion and a synthetic resin film (95) are laminated, wherein both ends near the discontinuous portion are provided. A plurality of substantially annular coil plates (61) in which the copper foil (91) is exposed from the synthetic resin film (95) are laminated concentrically, and the copper foil (91) of each coil plate (61) is exposed. The end portions (65, 67) are overlaid on each other and soldered, and the coil plates (61) are stacked in a short cylindrical shape, and the copper foil (91) of each coil plate (61) is successively spirally successively formed. (95) For a transformer in which an annular synthetic resin film is disposed between the copper foil (91) of each coil plate (61) so as to remove the soldered ends (65, 67). It is a coil.
[0014]
In this manner, the vicinity (65, 67) of the end of the same coil plate (61) is soldered, and the copper foil (91) is formed by the synthetic resin film (95) except for the soldered end (65, 67). Since the coil and the copper foil (91) are insulated from each other, a coil for a transformer wound in a large number can be easily manufactured.
[0015]
Further, since the coil is formed by successively arranging the annular copper foils (91) in a flat plate shape, the coil can be formed thin even if the current capacity is large.
[0016]
Furthermore, since a copper foil (91) and a synthetic resin film (95) are laminated, and a large number of flat annular flexible substrates having discontinuous gaps in part are laminated concentrically to form a coil, When winding the coil, it is possible to easily prevent the winding from being biased.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIGS. 1 and 2, the transformer according to the present invention includes a primary coil 80 in which a large number of primary coil plates are stacked between an upper core body 11 and a lower core body 15, and a plurality of secondary coil plates. And is formed by sandwiching the copper plate 40 as an example.
[0018]
The upper core body 11 and the lower core body 15 have the same shape, and the upper core body 11 has a cylindrical upper central iron core 12 at the center, and the lower core body 15 has a cylindrical lower central iron core 16 similarly. The upper core body 11 has plate-like arms 14 on the left and right sides from the end of the upper central core 12, and has outer cores 13 in the same direction as the central core 12 from the outer ends of the arms 14, respectively. The lower core body 15 has a plate-like arm portion 18 on the left and right from the end of the lower central core 16, and has an outer iron core 17 in the same direction as the central core 16 from the outer end of the arm portion 18. When the end of the central core 12 and the end of the lower central core 16 are abutted, the end of the upper outer core 13 and the end of the lower outer core 17 are also abutted, and the central cores 12 and 16 and the arms 14 and 18 are joined. And outer cores 13 and 17 It is intended to form a magnetic path of the scan 10.
[0019]
Also, this primary coil 80 has one primary coil plate 51 for the first end shown in FIG. 3A and one primary coil plate 71 for the second end shown in FIG. 3C. A combination of a plurality of the connecting primary coil plates 61 shown in FIG.
[0020]
It is to be noted that the primary coil 80 may be formed by using a plurality or a large number of the connection primary coil plates 61 alone without using the first end primary coil plate 51 or the second end primary coil plate 71. .
This first end portion primary coil plate 51 has a connection terminal portion 57 at one end of a copper foil serving as a main body portion 53 having a discontinuous portion and having a substantially annular shape, and an annular shape at the other end. The upper and lower surfaces of the conductor 59, which is a lead terminal 55 projecting outward from the main body 53, are made of an insulating synthetic resin film such as polyimide except for both ends of the connection terminal 57 and the lead terminal 55. To cover.
[0021]
In addition, the second end primary coil plate 71 has a connection terminal part 77 at one end of a copper foil serving as a main body part 73 having a discontinuous portion and having a substantially annular shape, and has a ring shape at the other end. The upper and lower surfaces of a copper foil, which is a conductor 79 serving as a lead terminal portion 75 protruding outward from the main body portion 73, are made of a synthetic resin film such as polyimide except for both end portions serving as the connection terminal portion 77 and the lead terminal portion 75. It is covered with.
[0022]
The connecting primary coil plate 61 has a first terminal portion 65 which is a terminal portion for connecting one end of a copper foil to be a substantially annular main body portion 63 having a gap which is a discontinuous portion. The other end is also a second terminal portion 67 which is a terminal portion for connection. Both ends of the upper and lower surfaces of a copper foil as a conductor 69 are defined as a first terminal portion 65 and a second terminal portion 67. Except for covering with a synthetic resin film such as polyimide.
[0023]
The center angle α of the connection terminal portion 57 in the first end portion primary coil plate 51, the center angle α of the connection terminal portion 77 in the second end portion primary coil plate 71, the first angle in the connection primary coil plate 61. The central angle α of the terminal portion 65 and the central angle α of the second terminal portion 67 in the connection primary coil plate 61 are all the same.
[0024]
As shown in FIG. 4C, the conductors 59, 69, and 79 are formed by depositing copper foil 91 on both surfaces of a polyimide-based synthetic resin film 95 called a flexible substrate. As shown in FIG. 4A and FIG. 4B, a laminate of a synthetic resin film 95 having copper foils 91 on both surfaces and the copper foils 91 is formed in the shape of predetermined primary coil plate conductors 59, 69, 79, As shown in FIG. 4D, the conductors 59, 69, and 79 having the three-layer structure are covered with a polyimide-based synthetic resin film 95 except for the respective terminals, and the first end shown in FIG. The primary coil plate 51, the primary coil plate 71 for the second end and the primary coil plate 61 for connection are connected to the primary coil plate 51 for the first end and the primary coil plate 71 for the second end. The terminal portions 57 and 77 and the first terminal portion 65 of the primary coil plate 61 for connection, The second terminal portion 67 is intended to provide a through-hole 93.
[0025]
The connection terminal portions 57 and 77 of the first end primary coil plate 51 and the second end primary coil plate 71, and the first terminal portion 65 and the second terminal portion 67 of the connection primary coil plate 61, respectively. Is applied with cream solder, the connection terminal portion 57 of the first end primary coil plate 51 and the first terminal portion 65 of the connection primary coil plate 61 are overlapped, and one of the required number of connection primary coil plates 61 The second terminal portions 67 of the connection primary coil plate 61 are sequentially overlapped with the first terminal portions 65 of the other connection primary coil plates 61, and the second terminal portion 67 of the last connection primary coil plate 61 is The first end primary coil plate 51, the connection primary coil plate 61, and the second end primary coil plate 71, which are stacked concentrically on the connection terminal portion 77 of the second end primary coil plate 71, are jigs. Heat treatment in the state of pressure bonding with It is an coil 80.
[0026]
The primary coil plate 51 for the first end, the primary coil plate 71 for the second end, and the primary coil plate 61 for connection are not limited to the case where the copper foil 91 and the synthetic resin film 95 have a five-layer structure. In some cases, both surfaces of the foil 91 may have a three-layer structure with the synthetic resin film 95, or may have a two-layer structure in which the copper foil 91 and the synthetic resin film 95 each have one layer.
[0027]
In the case of the five-layer structure or the three-layer structure, the lead terminal portions 55 and 75 and the connection terminal portions 57 and 77 of the primary coil plate 51 for the first end and the primary coil plate 71 for the second end, and the connection The first terminal portion 65 and the second terminal portion 67 of the primary coil plate 61 are not limited to the case where the upper and lower surfaces of the conductors 59, 69, and 79 are exposed, and only the upper surface or the lower surface is a conductor. Each terminal portion may be formed by exposing 59, 69, and 79. In the two-layer structure, both surfaces of the copper foil 91 are exposed without providing the synthetic resin film 95 near one end of the copper foil 91. To form each terminal portion.
[0028]
When the primary coil 80 having a required number of turns is formed by the single primary coil plate 51 for the first end and the primary coil plate 71 for the second end and the required number of connecting primary coil plates 61, the primary coil The number of turns of 80 is n, and the central angle at which the gap between the extraction terminal portion 55 and the connection terminal portion 57 of the first end primary coil plate 51 is formed as shown in FIG. As shown in FIG. 5B, assuming that the central angle at which the gap between the extraction terminal portion 75 and the connection terminal portion 77 of the second end primary coil plate 71 is θ2 is m, the number of connection primary coil plates is m. Assuming that 61 is used, the central angle β between the first terminal portion 65 and the second terminal portion 67 in the connecting primary coil plate 61 is
[0029]
(Equation 1) β = {360 × (n−2) + θ1 + θ2} m
Thus, the circumferential length of the connecting primary coil plate 61 can be determined.
However, (Equation 2) β <360−2α
Is satisfied, and m is determined so that β becomes the maximum in a range satisfying Expression 2.
[0030]
Therefore, for example, when the primary coil 80 having 10 turns is formed, the center angle θ1 and the second end where the gap between the extraction terminal portion 55 and the connection terminal portion 57 of the first end primary coil plate 51 is formed. The central angle θ2 formed by the gap between the lead terminal portion 75 and the connection terminal portion 77 of the primary coil plate 71 is 30 degrees, the central angle α of the connection terminal portion 55 in the first end primary coil plate 51, The center angle α of the connection terminal 77 in the second end primary coil plate 71, the center angle α of the first terminal 65 in the connection primary coil plate 61, and the center angle α of the second terminal 67 in the second terminal 67 are 20 degrees. If
β = ｛360 × (10−2) + 30 + 30｝ ÷ 9 ≒ 326.7
β = ｛360 × (10−2) + 30 + 30｝ ÷ 10 = 294
In order to satisfy (Equation 2) β <360−2α = 360−40 = 320, ten connecting primary coil plates 61 having a center angle β of 294 degrees are used.
[0031]
The first end primary coil plate 51 and the second end primary coil plate 71 may have the same shape, and the first end primary coil plate 51 may be used as the second end primary coil plate 71. Yes, the primary coil plate 51 for the first end and the primary coil plate 71 for the second end are omitted, and only a large number of the primary coil plates 61 for connection are connected, and the primary coil for connection is formed by stacking many sheets. Lead wires may be provided from the second terminal portion 67 of the connection primary coil plate 61 located at the upper end of the plate 61 and the first terminal portion 65 of the connection primary coil plate 61 located at the lower end.
[0032]
Further, when the primary coil 80 is formed by using the first end primary coil plate 51, the connecting primary coil plate 61, and the second end primary coil plate 71, the primary end primary coil plate having a fixed shape is used. In order to manufacture the primary coil 80 having a predetermined number of turns using the coil plate 51, the second end primary coil plate 71, and the required number of connection primary coil plates 61, as described above, the connection primary coil plate 61 is used. The present invention is not limited to the case where the circumferential length and the number of the connecting primary coil plates 61 are determined to form and manufacture the connecting primary coil plate 61. A predetermined number of turns is determined, and the first end primary coil plate 51 whose center angle θ1 is adjusted or the second end primary coil plate 71 whose center angle θ2 is adjusted is connected to both ends of the connection primary coil plate 61. And the primary coil for the first end 51 lead-out terminal portion 55 of sometimes a primary coil 80 of the required number of turns and a lead-out terminal portion 75 is pulled out from the parallel to the main body portion 53, 63, 73 of the second end for the primary coil plate 71.
[0033]
Also, it is necessary to connect the required number of predetermined primary coil plates 61 for connection to the first end primary coil plate 51 whose central angle θ1 is adjusted or the second end primary coil plate 71 whose central angle θ2 is adjusted. Not only in the case where the number of windings is the primary coil 80, but also the lead terminal of the first end primary coil plate 51 in one of the primary coils 80 using two identical primary coils 80 having the number of windings of 10 described above. The predetermined number of turns is set such that the two primary coils 80 are connected in series and the number of turns is 20 as the primary coil by connecting the portion 55 and the lead terminal portion 75 of the second end primary coil plate 71 in the other primary coil. The required number of primary coils 80 may be prepared and connected in series using the lead terminal portions 55 and 75 of each of the primary coils 80 to form the required number of turns of the primary coil.
[0034]
Then, the primary coil using the first end primary coil plate 51, the second end primary coil plate 71, and the connecting primary coil plate 61 in which the copper foil 91 is vapor-deposited on the flexible substrate has one turn. The thickness can be reduced to 100 μm to 500 μm, and the width of the conductors 59, 69, 79 made of the copper foil 91 is about 1 cm, so that a current capacity of several tens of amperes is provided and the current capacity is relatively large. The primary coil 80 can be easily reduced in size and weight.
[0035]
1 and 6, the secondary coil plate 40 of the transformer 10 is formed by a copper plate 40 having a flat annular coil portion 41 and a coil terminal portion 45 protruding from the coil portion 41. A gap 43 is provided in a part of the coil section 41, and a coil terminal section 45 is provided at both ends sandwiching the gap 43 to form a secondary coil having one turn by one copper plate 40.
[0036]
When a plurality of copper plates 40 are used as the secondary coil plates, an insulating plate 31 made of synthetic resin is interposed between the secondary coil plates 40 as shown in FIGS. By connecting the coil terminal portions 45 of the secondary coil plate 40 to each other via a conductive spacer 35 corresponding to the thickness of the secondary coil plate, the copper plate 40 as the secondary coil plate is connected in series and has a plurality of turns. It is a secondary coil.
[0037]
Also, the inner diameters of the main body portions 53, 63, 73 of the first end primary coil plate 51, the second end primary coil plate 71 and the connecting primary coil plate 61, and the coil portion 41 of the secondary coil plate 40. And the inner diameter of the insulating plate 31 are the same, and the outer diameters of the main body portions 53, 63, 73 of the primary coil plate 51 for the first end, the primary coil plate 71 for the second end, and the primary coil plate 61 for connection. The outer diameter of the coil portion 41 of the secondary coil plate 40 is the same as or slightly smaller than the outer diameter of the main body such as the primary coil plate 61 for connection. Is made equal to or slightly larger than the outer diameter of the main body such as the primary coil plate 61 for connection.
[0038]
Then, the primary coil 80, the insulating plate 31, and the secondary coil plate 40, which are connected by concentrically overlapping the first end primary coil plate 51, the connecting primary coil plate 61, and the second end primary coil plate 71, are connected. As shown in FIG. 1, the central pipe 23 of the protection body 20 is formed by connecting the central coil 23 of the protector 20 to the primary coil plate 51 for the first end, the primary coil plate 61 for connection, and the primary coil for the second end. The primary coil 80, the insulating plate 31, and the secondary coil plate 40, which are formed by the connecting primary coil plate 61 and the like penetrating through the plate 71, the insulating plate 31, and the secondary coil plate 40, are made coaxial.
The protector 20 has a hollow pipe-shaped central pipe 23 and a base plate 21 which is an annular plate-like body formed in a flange shape from an end of the central pipe 23. The inner diameters of the main body parts 53, 63, 73 of the first end primary coil plate 51, the second end primary coil plate 71, and the connecting primary coil plate 61, the inner diameter of the coil part 41 of the secondary coil plate 40, The inner diameter of the central pipe 23 is substantially the same as the outer diameter of the upper central core 12 of the upper core body 11 and the lower central iron core 16 of the lower core body 15, and the outer diameter of the substrate portion 21. Is the same as the outer diameter of the insulating plate 31.
[0039]
Therefore, as shown in FIG. 1, the central pipe 23 of the protection body 20 is formed by connecting the primary coil plate 51 for the first end, the primary coil plate 61 for the connection and the primary coil plate 71 for the second end in an overlapping manner. Inserted into the coil 80, inserted into the secondary coil plate 40 via the insulating plate 31, further inserted into the insulating plate 31 and the secondary coil plate 40, and inserted into the primary coil 80 via the insulating plate 31, and finally the protective cap 25, and sequentially attached to the central pipe 23, and the upper central iron core 12 of the upper core body 11 and the lower central iron core 16 of the lower core body 15 are inserted into the central pipe 23 to form the transformer 10 as shown in FIG. Can be done.
The protective cap 25 is made of a synthetic resin plate having an annular shape in which the inner diameter matches the outer diameter of the central pipe 23 and the outer diameter matches the outer diameter of the substrate portion 21. Shape.
[0040]
Also, in the transformer 10 shown in FIGS. 1 and 2, two secondary coil plates 40 are connected in series by a conductive spacer 35 so that the number of turns of the secondary coil is two, and the two primary coils 80 are electrically conductive. The current capacity of the primary coil is increased by connecting the terminal coils 37 in parallel with each other through a terminal pin 37 having a characteristic.
However, the number of windings of the secondary coil can be adjusted by serially connecting the required number of secondary coil plates 40 with the required number of the secondary coil plates 40 sandwiching the insulating plate 31 therebetween, and the primary coil 80 can also be connected to the primary coil plate 61 for connection. There is a case where one primary coil having a predetermined number of turns is used depending on the number of sheets, or a case where a plurality of primary coils 80 are connected in series to determine the number of turns of the primary coil. The current capacity may be adjusted in parallel.
[0041]
As described above, in the transformer 10 according to the present embodiment, the primary coil 80 that performs a large number of windings has the annular thin plate-shaped primary coil plate 51 for the first end and the primary coil plate for the connection, which are formed in the shape of an annular thin plate having the same inner and outer diameters. The primary coil 61 and the second end primary coil plate 71 are overlapped, and the secondary coil is also formed by overlapping the flat secondary coil plate 40 having substantially the same inner diameter and outer diameter as the primary coil 80. Therefore, it is possible to prevent variations in inductance due to irregularities in the distance between the winding and the iron core.
[0042]
In the transformer 10, the primary coil 80 is formed by a large number of thin-film connecting primary coil plates 61 and the like, and the secondary coil is formed by a plurality of secondary coil plates 40. The transformer 10 can be a large transformer, the outer diameter of the transformer coil is about 4 cm, the thickness of the transformer coil is about 1.5 cm, the thickness of the transformer 10 is about 3 cm, the width is about 5 cm, and the primary coil extraction terminal 55 , 75 to the coil terminal 45 of the secondary coil is approximately 6 cm, and the transformer 10 has a capacity of 1 KVA for converting a primary voltage of 100 V to a secondary voltage of approximately 10 V. .
[0043]
Further, the temperature difference between the inside and outside of the primary coil 80 and the secondary coil is reduced, and the transformer 10 having excellent heat radiation characteristics can be obtained, and the transformer 10 having good frequency characteristics can be obtained.
[0044]
【The invention's effect】
The present invention described in claim 1 can provide a small-sized transformer as a thin coil even if the current capacity is large, and can provide a transformer with small variation in inductance and excellent heat radiation characteristics. Things.
[0045]
Further, according to the present invention described in claim 2, in addition to the features of the invention described in claim 1, it is possible to easily manufacture a small-sized transformer.
The present invention described in claim 3 is a transformer coil in which the thickness of the coil is reduced, the size of the coil is reduced, and it is easy to assemble a transformer having a large current capacity, the variation in inductance is small, and the heat radiation characteristics are excellent. It is possible to provide a transformer coil.
[Brief description of the drawings]
FIG. 1 is an exploded view showing an embodiment of a transformer according to the present invention.
FIG. 2 is a perspective view showing an embodiment of a transformer according to the present invention.
FIG. 3 is a diagram showing an example of each primary coil plate used in the transformer according to the present invention.
FIG. 4 is a view showing a conductor of each primary coil plate used in the transformer according to the present invention.
FIG. 5 is a diagram showing a primary coil used in the transformer according to the present invention and respective primary coil plates forming the primary coil.
FIG. 6 is a diagram showing an example of a secondary coil plate and an insulating plate used in the transformer according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Transformer 11 Upper core body 12 Upper central iron core 13 Upper outer iron core 14 Arm part 15 Lower core body 16 Lower central iron core 17 Lower outer iron core 18 Arm part 20 Protector 21 Substrate part 23 Central pipe 25 Protective cap 31 Insulating plate 35 Conductive spacer 37 Terminal pin 40 Secondary coil plate (copper plate) 41 Coil portion 43 Gap 45 Coil terminal portion 51 Primary coil plate for first end 53 Main body portion 55 Pull-out terminal portion 57 Connection terminal portion 59 Conductor 61 Primary coil plate for connection 63 Main body 65 First terminal 67 Second terminal 69 Conductor 71 Primary coil plate for second end 73 Main body 75 Leader terminal 77 Connection terminal 79 Conductor 80 Primary coil 91 Copper foil 93 Through hole 95 Synthetic resin film

Claims (3)

An annular flexible substrate with a copper foil and a synthetic resin film laminated on each other and with a discontinuous gap in part, with the synthetic resin film laminated on the copper foil surface except for the copper foil near both ends. A large number of primary coil plates, each of which has a copper foil near both ends and a connection terminal portion, are sequentially connected to each other at the connection terminal portion and concentrically stacked to form a primary coil having a plurality of turns. A secondary coil is formed by forming a copper plate having a flat plate annular shape having substantially the same inner diameter and outer diameter as the primary coil and partially having a discontinuous gap, and having the same inner diameter and outer diameter as the primary coil. A transformer characterized in that a copper plate serving as a secondary coil is sandwiched between insulating plates having a flat annular shape having a diameter and having no discontinuous portions. A primary coil in which a number of primary coil plates of the same shape are connected and laminated, and a secondary coil in which a plurality of copper plates are stacked with an insulating plate interposed therebetween and the copper plates are connected in series, the primary coil and the secondary coil The transformer according to claim 1, wherein the coil and the coil are coaxially stacked and attached to an iron core. This is a flexible substrate in which a copper foil and a synthetic resin film each having a discontinuous portion and a substantially annular shape are laminated, and the copper foil at both ends near the discontinuous portion is exposed from the synthetic resin. A plurality of coil plates are laminated concentrically, the exposed ends of the copper foil of each coil plate are overlaid and soldered together, and the coil plates are stacked in a short cylindrical shape, and the copper foil of each coil plate is sequentially stacked. Wherein the synthetic resin film having an annular shape is arranged between the copper foils of the coil plates so as to remove the soldered end portions.

Images