JPS58155711A - Flat coil for power source transformer - Google Patents

Abstract

PURPOSE:To obtain a flat coil having uniform characteristic which is useful for reducing the size and thickness of a transformer by using a substrate or an insulation film on which eddy like patterns are formed by etching or printing as a coil for a power source transformer. CONSTITUTION:As a coil for a transformer of a switching power source, inner layer circuits 56, 57 are formed by preparing eddylike patterns on an insulation substrate or insulation film by printing, etching, vaporization method, etc. Shield layers 58, 59 covering the whole coil are provided. Primary coil terminals 512, 513 are connected to the circuits 56, 57 by through-hole plating, etc., and similarly secondary coil terminals 514, 515 are connected to the circuits 56, 57. In the circuits 56, 57, the primary and secondary coils are formed so that they are separated and independent from each other. The flat coil thus processed is combined with platelike magnetic cores 517a, 517b to form a power source transformer. Due to this, the coil has uniform characteritic and the leakage of magnetic flux is reduced as it is covered with shield layers and it is useful for reducing the size and thickness of a transformer.

Description

[Detailed description of the invention] The present invention is used for industrial equipment and consumer equipment.

This relates to a coil for a transformer in a switching power supply, and is a coil made by creating spiral turns on an insulating substrate or insulating film by printing, etching, vapor deposition, etc., and combining this flat coil with a plate-shaped magnetic core. A transformer is formed and used as a power transformer. The purpose is to provide a high-performance transformer that is smaller in size, thinner, and cheaper than conventional ones.

11E+ to FIG. 4 for convenience. Regarding each side of a general switching power supply, FIGS. 1 and 3 are front views, and FIGS. 2 and 4 are side views of the examples shown in FIGS. 1-5, respectively. Identical parts are designated by the same reference numerals in FIGS. 1 and 2, and in FIGS. 3 and 4.

In FIG. 811 and FIG. 2, a coil 12 is formed by winding an enameled wire or a steel wire around a bobbin 11,
Attach the bobbin IIK magnetic core 15α<sb with this winding, and butt the i cores 15a and 156? Le.

FIG. 5 and FIG. 4 show an example in which the magnetic cores 35α and 55bfI are butted together and then fastened with tape 39 and fixed to a transformer board 51 to which lead terminals 35 are fixed. After winding,
The shield plate 54 is wound.

In coils manufactured using such conventional wire winding methods, there are large variations in coil inductance and coupling coefficient between coils.
There was a drawback that a uniform and high-performance coil could not be manufactured. Furthermore, it is difficult to completely automate the process of inserting an interlayer insulation film and processing the coil lead wires for coils using the single-winding method.
It had the disadvantage of being expensive. 7 The transformer coil according to the present invention eliminates the above-mentioned drawbacks, and the front view and plan view are shown in Figure @5 and Figure @d, respectively.
FIG. 7 is a perspective view of a combination transformer formed with a magnetic core. In the figure, 56 and 57 are inner layer circuits, and 58 and 59 are shield layers that cover the entire coil. 512, 515
is a primary coil terminal, which is connected to inner layer circuits 56 and 57 by through-hole plating. Similarly, the secondary coil is %
It is formed from terminals 514 and 515 and inner layer circuits 56 and 57. The inner layer circuit has a structure in which the primary and secondary coils are independently separated using through holes and the like.

As shown in this example, the coil according to the present invention has more uniform characteristics than conventional wire-wound coils, and since the entire coil is covered with a shield layer, leakage magnetic flux is also reduced. This makes it possible to obtain a coil with good performance.

In addition, it can be made very thin in terms of shape, and is suitable for manufacturing flat devices, which is a recent demand in the market.

[Brief explanation of drawings]

Figure 1 is a front view of the conventional example. Figure 2 is the II of the example shown in Figure 1.
Front view FIG. 5 is a front view of another conventional example, FIG. 4 is a side view of the example shown in FIG. 5, FIG. 5 is a front view of the embodiment, FIG. 6 is a plan view of the same, and FIG. is the same perspective view. I11 bobbin, 34I shield plate, 51211 primary coil terminal, 51412 secondary coil terminal 517α1 magnetic core,
517Al magnetic core. SaifwJ Sai2 Figure// Figure 3 'f-4 Figure 5. 32 Rest Figure 5 off diagram

Claims (1)

[Scope of Claims] 1. A flat coil for a power transformer, characterized in that spiral turns are created on a substrate or an insulating film by etching, printing, and rinsing. It is used for a coil of a power transformer. 2. , Claim 1 is characterized in that a plurality of coils in a multi-output power supply are integrated by multilayering the coils, and the surface layer of the multilayer coil is used as a shield layer to shield the entire coil. Flat coil for power transformer as described in section.