JPH0645318U - Sheet coil and sheet coil transformer - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] In the conventional sheet coil transformer, it was necessary to secure a creepage distance in space due to safety standards.
According to the present invention, the coil pattern is a multi-layer laminated substrate, the conductive portion is embedded with an insulating base material, and the thickness of the insulating substrate can be regarded as an insulation distance. The purpose is to provide a sheet coil transformer. [Structure] A coil pattern is arranged between layers of a multi-layered substrate having two or more layers, and a through hole is provided at the center of the substrate.
Coil and sheet coil transformer using the same and 1
A sheet coil transformer whose secondary / secondary winding ratio is such that the secondary voltage is a safe ultra-low voltage or less.

Description

[Detailed description of the device]

[0001]

[Field of Invention]

 The present invention relates to a thin transformer and a multi-layer sheet coil for the transformer, which take into consideration the insulation distance in safety standards.

[0002]

[Prior art]

 FIG. 1 is an assembly view of a conventional sheet coil, and FIG. 2 is an assembly diagram of a sheet coil transformer using the same sheet coil. In FIG. 1, spiral coil patterns 2 and 3 are formed on the front and back surfaces of the insulating substrate 1, and the terminals of the front coil pattern 2 and the back coil pattern (2) The terminals of the pattern 3 are passed through. The hole member 4 is connected by, for example, through-hole plating.

A winding start terminal portion 5 and a winding end terminal portion 6 of the sheet coil thus formed are provided on the front and back of the insulating substrate 1. A through hole 7 for passing a core is provided near the center of the spiral coil pattern to form a sheet coil as shown in FIG.

A simple transformer can be obtained by combining two sheets of this sheet coil, sandwiching an insulating plate between them, and penetrating the core through the through hole at the center. In FIG. 2, a primary winding 8 made of one sheet coil and a secondary winding 9 made of another sheet coil are sandwiched by three insulating plates 10a, 10b, 10c. Of course, the insulating plate also has a through hole 7 having the same shape as the sheet coil. The upper and lower insulating plates are provided with a lead terminal 11 for the primary coil and a lead terminal 12 for the secondary coil, respectively.

Next, the upper core 13 and the lower core 14 are passed through the through holes 7 and fixed to form a sheet coil transformer.

However, in the sheet coil transformer formed in this manner, since the coil and the coil and the core are only sandwiched by the insulating plates, the creeping distance l between the coil and the core is especially safe at the creepage distance l. A standard insulation distance must be secured.

For example, in a transformer of UL standard (UL-1411) audio, radio and television type, in the case of AC100VK, the creepage distance l between primary and secondary and between primary and secondary and the core is Each must secure 1.6 mm or more.

When forming a coil pattern with a large number of turns on a substrate area as small as possible, (3) it is virtually impossible to secure a creeping distance 1 between the coil and the core in consideration of safety standards.

[0009]

[The purpose of the device]

 In the conventional sheet coil transformer, the creepage distance of the space must be ensured according to the safety standard, and the size of the transformer becomes large. In the present invention, by making the coil pattern a multilayer laminated board, the coil conductive part is covered so as to be embedded with an insulating base material, and the thickness of the insulating board is regarded as an insulating distance, and a smaller sheet coil transformer is obtained. The purpose is to produce.

[0010]

【Example】

 FIG. 3 (a) is a plan view of a sheet coil using the multilayer laminated substrate of the present invention, and FIG. 3 (b) is a sectional view taken along line AA '. As shown in FIG. 3B, a coil pattern 16 made of copper foil or the like is printed on each layer except the surface of the multilayer laminated substrate 15, and coil ends between the layers are connected by an internal through hole 17. There is.

A winding start terminal portion 5 and a winding end terminal portion 6 are printed on the front surface and the back surface of the multilayer laminated substrate 15, and a coil pattern 16 is connected by an internal through hole 17.

Further, a through hole 7 for the core is provided near the center of the multilayer laminated substrate 15. When such a multilayer laminated substrate 15 is viewed from the front surface or the back surface, it becomes as shown in FIG.

The multi-layer laminated substrate is manufactured by printing a coil pattern for each layer using a ceramic substrate and then firing it at high temperature and high pressure. Since the layers are integrated without any gap, the distance between the conductors and between the conductor and the core can be regarded as the insulation distance of the thickness, not the creepage distance of the space.

(4) Therefore, the insulation distance L between the coil pattern and the core can be set to 0.3 mm or more in the case of AC100VK according to UL safety standards. Conventionally, the creepage distance of the board was required to be 1.6 mm or more, but in the case of the present invention, the insulation distance can be increased with the thickness of the insulator of 0.3 mm or more, so the coil pattern occupies the board area. The rate is much more favorable.

A sheet coil transformer can be manufactured as shown in FIG. 4 by using the sheet coil thus formed. If the primary side substrate 18 and the secondary side substrate 19 which are multi-layer laminated substrates are superposed, the upper core 13 and the lower core 14 are assembled, and the primary side terminal 11 and the secondary side terminal 12 are respectively taken out, the present invention A sheet coil transformer can be created. In this case, since the conductor portion of the coil is embedded in the multilayer laminated substrate, the insulation distance from the core can be specified by the thickness of the substrate.

If the primary coil pattern and the secondary coil pattern are formed by using one multi-layer laminated substrate, the primary and secondary integrated substrate 20 shown in FIG. 5 can be obtained, and the primary side terminal 1 can be formed on this substrate. If the primary and secondary terminals 12 are taken out and the upper core 13 and the lower core 14 are assembled, a sheet coil transformer with a single multilayer laminated substrate can be manufactured.

In addition, the sheet coil as described above cannot increase the number of turns of the coil as compared with the ordinary winding. Considering the current capacity and the like, it is considered that the maximum is about 10 turns per sheet. Therefore, it is necessary for the safety standard to make use of this fact to make a sheet coil transformer with a winding ratio that keeps the maximum voltage on the secondary side below the voltage that satisfies the safety standard.

The insulation transformer referred to in the safety standard is not only the insulation performance between the primary and the secondary or between the primary and the secondary and the core, but also the maximum voltage on the secondary side is a safety ultra low voltage SELV (SAFET Y EXTRA). (5) Unless it is less than LOW VOLTAGE).

For example, there is IEC950 as a typical safety standard. According to this, the safety ultra-low voltage SELV, which is safe without being touched by humans, has a peak value of 42.4 V or a direct current of 60 V or less. .

The structure of the sheet coil transformer using the multilayer laminated substrate of the present invention is such that the insulation distance between the primary and secondary cores is limited to the safety standard distance, and the number of turns between the primary and secondary windings is limited. It is necessary to reduce the ratio to the margin of the safety standards mentioned above.

For example, when the AC240V input is taken as an example, the primary-to-secondary turns ratio is limited to about 8: 1 to 10: 1. Therefore, within this range, the secondary voltage has a peak value of 42.4V or DC. A power supply system satisfying the safety standard can be proposed by selecting the winding ratio so that the voltage becomes 60 V or less and making the above-mentioned sheet coil transformer.

[0022]

[Effect of device]

 By using the sheet coil and sheet coil transformer according to the present invention, it is possible to make a transformer and a power supply system satisfying safety standards small in size and economical in manufacturing process. In addition, the printed circuit board manufacturing plant and its processes are certified as safety standards such as UL, which has the advantage of ensuring high quality from materials to product dimensions.

[Brief description of drawings]

FIG. 1 Conventional sheet coil

FIG. 2 is an assembly diagram of a sheet coil transformer using a conventional sheet coil.

FIG. 3 (a) is a plan view of a sheet coil transformer using the multilayer laminated substrate of the present invention (6).

FIG. 3 (b)

FIG. 3A is a sectional view taken along line AA ′ of FIG.

[Fig. 4] Assembly drawing of the sheet coil transformer of the present invention

FIG. 5 is another example of the assembly drawing of the sheet coil transformer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Front coil pattern 3 Back coil pattern 4 Through-hole member 5 Winding start terminal portion 6 Winding end terminal portion 7 Through hole 8 Primary winding consisting of a sheet coil 9 consisting of a sheet coil 2 Secondary winding 10a, 10b, 10c Insulation plate 11 Lead terminal of primary coil 12 Lead terminal of secondary coil 13 Upper core 14 Lower core 15 Multilayer laminated substrate 16 Coil pattern 17 Internal through hole 18 primary side substrate 19 secondary side substrate 20 primary and secondary integrated substrate l creepage distance (7) L insulation distance

Claims (3)

[Scope of utility model registration request] 1. A coil pattern is disposed between layers except a front surface and a back surface of a multi-layer laminated substrate having two or more layers, and a terminal of each coil pattern uses a through-hole member as needed. Electrically connected to form one or more sets of coils,
The terminals of each of the one or more sets of coils are arranged on one or both surfaces of the front surface or the back surface of the multi-layer laminated board, and a hole penetrating the transformer core is formed near the center of the coil of the multi-layer laminated board. A multi-layered sheet featuring things
Tocoir. 2. Arrangement of one sheet coil according to claim 1 of the utility model registration, or stacking two or more sheet coils,
A sheet coil transformer characterized by forming an insulating transformer by combining cores. 3. The sheet coil transformer according to claim 2 of the utility model registration, wherein the secondary and Nth voltages of the transformer are equal to or less than a safety ultra-low voltage in terms of safety standards. A sheet coil transformer, wherein one sheet coil having second, second and Nth turn ratios is arranged or two or more sheet coils are stacked and cores are combined to form a transformer.