KR101964079B1

KR101964079B1 - Process for preparing silver-coated and surface-expanded spiral wire for high efficiency and high frequency transformer

Info

Publication number: KR101964079B1
Application number: KR1020120134925A
Authority: KR
Inventors: 형기우; 신대정; 형성훈; 류인재; 조성효; 양정수
Original assignee: 동양하이테크산업주식회사
Priority date: 2012-11-27
Filing date: 2012-11-27
Publication date: 2019-08-01
Also published as: KR20140070759A

Abstract

The present invention relates to a silver coated surface extended spiral wire manufacturing method for manufacturing a high efficiency high frequency transformer and a silver coated surface extended spiral wire manufactured by the method. According to the present invention, it is possible to manufacture an electric power component capable of suppressing an increase in AC resistance, preventing an increase in the temperature of a coil / transformer, and achieving high efficiency, high performance, miniaturization and high speed of electric power devices. In addition, it is possible to produce RITZ wires with high conductivity, enhanced heat resistance, bright and shiny appearance, and excellent corrosion resistance.

Description

Technical Field [0001] The present invention relates to a silver-coated surface expanded spiral wire manufacturing method for manufacturing a high-efficiency high frequency transformer,

The present invention relates to a silver coated surface extended spiral wire manufacturing method for manufacturing a high efficiency high frequency transformer and a silver coated surface extended spiral wire manufactured by the method.

The Litz wire generally refers to a conductor wire constituting a transformer, in which twisted micro wire bundles are individually insulated or made in a woven pattern of a uniform pattern. Ritz wire has higher impedance per unit cross section, but it is widely used because it can reduce cable impedance at high frequencies or significantly reduce cable thickness. The Litz wire is used to minimize power loss and to reduce the skin-effect in high frequency operation. The plurality of wire bundles suppress the increase of the AC resistance and prevent the temperature rise of the coil from one coarse wire having the same cross-sectional area, thereby enabling high-efficiency, miniaturization, and high-speed operation of power devices.

Transformers made with Litz wire in general are very effective at operating frequencies below 500 kHz, but not at frequencies above 1 MHz. At an operating frequency of several MHz or more, the wires must be finer due to the skin effect, but there is a limit to making fine wires using ordinary copper wires.

Patent Document 1: Korean Patent Laid-Open No. 10-2008-0075546 (2008.08.18) Patent Document 2: Korean Published Patent Application No. 10-2011-0005742 (January 18, 2011)

The inventors of the present invention have made intensive studies to fabricate a transformer capable of operating at a higher frequency than a conventional Litz wire. As a result, the present inventors have found that when fine polymer wires are coated with silver to twist a fine wire bundle, The present invention has been accomplished on the basis of confirming that the Ritz wire manufactured by the present invention can satisfy such requirements.

The present invention is very difficult to realize a Litz wire using a general conductor which can reduce the skin effect and the proximity effect at an operating frequency of several to several hundreds of MHz or more on one side, The purpose of the transformer is to fabricate a transformer using a silver coated surface extended spiral wire, which is twisted or twisted into a woven pattern of uniformly widened fine wire bundles.

The present invention, in a further aspect,

a) immersing the molten silver solution in a copper wire of 75 to 95 占 퐉 at a temperature of 1,070 to 1,080 占 폚 to apply a copper wire;

b) coating the copper wire having passed through the molten silver solution at a temperature of 35 to 120 rpm and cooling at room temperature to a thickness of 5 to 25 μm for 75 to 95 μm of copper;

c) heat treatment for a certain period of time at a predetermined temperature to increase the bonding strength between copper and silver, and at the same time, a polyvinyl acetal phenolics, polyurethane / nylon, polyester nylon, polyester-200 polyamide- Performing an insulating coating with the insulating material selected from the group;

d) performing a secondary insulation coating with an insulating material selected from the group consisting of glass fiber, Darkron glass, polyester-200, polyester A / I topcoat, polytetrafluoroethylene, polyamide- step; And

e) twisting or rotating the coating wire in one direction so as to form a bundle of 10 to 110 strands of the coating wire and a rotation of 0.83 to 1.26 per cm;

The present invention also provides a method of manufacturing a silver coated surface extended spiral wire for manufacturing a high efficiency high frequency transformer.

According to the present invention, it is possible to manufacture an electric power component capable of suppressing an increase in AC resistance, preventing an increase in the temperature of a coil / transformer, and achieving high efficiency, high performance, miniaturization and high speed of electric power devices. In addition, it is possible to produce RITZ wires with high conductivity, enhanced heat resistance, bright and shiny appearance, and excellent corrosion resistance.

1 is a schematic view of a coating wire;
Figure 2 is a schematic view of a coated wire bundle.

The present invention, in one aspect,

The present invention provides a method of manufacturing a silver coated surface extended spiral wire for manufacturing a high efficiency high frequency transformer.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in more detail with reference to the accompanying drawings.

The Litz wire is normally used in units of AWG as shown in Table 1 below.

Nominal diameter [mm] AWG Nominal resistance [Ω / m] 0.0245 50 36.26 0.0275 49 28.78 0.0310 48 22.65 0.0350 47 17.77 0.0390 46 14.31 0.0440 45 11.24 0.0500 44 8.706 0.0550 43 7.195 0.0630 42 5.484 0.0700 41 4.442 0.0780 40 3.577 0.0880 39 2.811 0.101 38 2.134 0.113 37 1.705 0.126 36 1.371 0.141 35 1.095 0.159 34 0.8609 0.179 33 0.6793 0.202 32 0.5334 0.225 31 0.4299 0.253 30 0.3400

Silver coated wire is insulated by polyvinyl acetal phenolics, polyurethane / nylon, polyester nylon, polyester-200 and polyamide-ML depending on the temperature used. Generally used one strand of Litz wire is 0.03 to 0.1 mm in diameter, but silver coated wires operate at higher frequencies, so it is preferable to make much smaller diameter 0.0245 mm (AWG 50) to 0.101 mm (AWG 38). Since it operates at a high frequency of several MHz or more, the diameter of one strand of copper wire is preferably 80 to 95% of the total diameter, and the thickness of the silver-coated copper wire is preferably 20 to 5%.

The outer surface of the silver coating is insulated to a thickness of several micrometers or less by using materials such as polyvinyl acetal phenolics, polyurethane / nylon, polyester nylon, polyester-200 and polyamide-ML mentioned above according to the use temperature. For pure copper, the electrical conductivity is 58.5 S * m / ㎟, but silver with a purity of 99.99% is 62.5S * m / ㎟.

In order to realize the RITZ wire, a thin silver is coated on the copper surface and heat treatment is performed to increase the strength of the bonding surface to increase the bonding strength. Coating and heat treatment are carried out at the same time. Since the melting point of copper is higher than that of silver at 961.78 ℃, it is 1,084.5 ℃, which is slightly lower than the melting point of copper, so the silver melted in copper atmosphere at 1070 ~ So that it can be coated naturally. In the case of a 44 AWG (0.050 mm) wire, the wire passing through the molten silver is cooled while rotating at 30 rpm for 5 seconds, thereby realizing the coating to a thickness of about 20 μm.

The structure of the wire coated with silver and coated with copper on the copper wire is shown in Fig. The plurality of silver coated wires fabricated in the same manner as in FIG. 1 are formed into a bundle as shown in FIG. 2 and twisted in one direction or rotated to manufacture a Litz wire. The number of turns twisted in one direction depends on the thickness of the silver coated wire and the number of strands of wire that make up a bundle. One turn per unit Cm for a bundle of 50 wires of 44 AWG Twist.

Table 2 below shows experimental data on the optimal number of turns and turns used per wire standard.

Specifications (AWG) Number of bundles Number of turns (per cm) 39 10 0.83 40 12 0.85 41 14 0.88 42 27 0.91 43 35 0.95 44 50 One 45 80 1.1 46 106 1.26

Table 3 below shows the inductance change rate data according to the number of turns for 44 bundles of 44 AWG wire.

Number of turns (per cm) 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15 1.20 Inductance change rate (%, 1 kHz vs. 100 kHz operation)
3.53
2.86
2.24
1.69
1.24
1.27
1.35
1.42
1.43

In addition to the commercialization of the silver-coated RITZ wire itself, silver-coated RITZ wire can be used to make various electric and electric signal transmission parts.

Transformers, which are essential for high-performance and high-efficiency electric and electronic products, are produced by commercializing transformers that can show high efficiency in the high-frequency environment of MHz band and are commercialized in LED SMPS, medical transformers and high- It can be used as an available power component.

Claims

a) immersing the molten silver solution in a copper wire of 75 to 95 占 퐉 at a temperature of 1,070 to 1,080 占 폚 to apply a copper wire;
b) coating the copper wire having passed through the molten silver solution at a temperature of 35 to 120 rpm and cooling at room temperature to a thickness of 5 to 25 μm for 75 to 95 μm of copper;
c) heat treatment for a certain period of time at a predetermined temperature to increase the bonding strength between copper and silver, and at the same time, a polyvinyl acetal phenolics, polyurethane / nylon, polyester nylon, polyester-200 polyamide- Performing an insulating coating with the insulating material selected from the group;
d) performing a secondary insulation coating with an insulating material selected from the group consisting of glass fiber, Darkron glass, polyester-200, polyester A / I topcoat, polytetrafluoroethylene, polyamide- step; And
e) twisting or rotating the secondary insulating coated wire in one direction so as to form a bundle of 10 to 110 strands and a rotation of 0.83 to 1.26 per cm;
Wherein the silver coated surface extended spiral wire is fabricated by the method of manufacturing a silver coated surface extended spiral wire for manufacturing a high efficiency high frequency transformer.

The method of claim 1, wherein in step c), the insulating material comprises polyvinyl acetal phenolics, polyurethane / nylon, polyester nylon, polyester-200, polyamide-ML in a certain mixing ratio.

The method according to claim 1, wherein in step d), the insulating material is a glass fiber, Darkron glass, polyester-200, polyester A / I topcoat, polytetrafluoroethylene, polyamide- / RTI >