JPS6276509A - Thin type transformer - Google Patents

Abstract

PURPOSE:To obtain a transformer which is thin, and small and has a large capacity and no heat generation due to the iron loss in a high frequency region, by making adhesion with insulating adhesives and laminating plural amorphous magnetic alloy sheets and at least one plate coil connected with a lead wire. CONSTITUTION:A transformer block 1 consists of two sheet blocks 1a' which are made adhesion with required plural number of sheets 1a and laminated, two blocks 1b' consisting of made adhesion and laminated sheets 1b placed on both sides of the block 1a' and one block 1c' consisting of made adhesion and laminated sheets 1c placed nearly at the center of the whole. Two plate type coils 2a, 2b are buried in insulating adhesives 3 and a lead wire 4 is connected to the terminal of the coil, e.g., by welding or with conductive adhesives. Between the sheets, the sheet and the plate type coil are made adhesion with insulating adhesives, e.g., an organic synthetic resin such as epoxy resin and an electrical insulating layer is formed between the sheets and between the sheet and the plate type coil.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a thin transformer, and more specifically, since it has good magnetic properties in a high frequency range and is extremely small in size, it can be used as a transformer for, for example, a hybrid circuit. Concerning useful thin transformers.

[Technical Background of the Invention and Problems Therein] Various ratings of transformers have been determined, and most of them have a substantially cubic shape.

Recently, in the field of electrical and electronic devices, efforts have been made to make devices lighter, thinner, and smaller. However, if the transformer is larger than this circuit as in the past, the transformer occupies a large dead volume in the entire circuit, and the efforts to make the entire circuit lighter, thinner, and smaller are not satisfied. It can't be said that it's something to be forced to do.

Therefore, as part of efforts to make circuit 9 equipment lighter, thinner, and smaller, it is necessary to make the transformer thinner and smaller.

Based on such requirements, a small transformer having an iron core made of a ferrite sintered body has been developed.

However, the ferrite sintered body has a saturation magnetic flux density (BS
) is as small as around 4500G, so the core cannot be made sufficiently small, and there is no T, and the thermal conductivity is low, so there is a problem of poor heat dissipation.

[Object of the Invention] An object of the present invention is to provide a thin transformer that is smaller than the above-mentioned small transformer and has less iron loss even in a high frequency range.

[Summary of the Invention] The present inventors have focused on the fact that the transformer capacity is proportional to the product of Bs of the iron core and the effective cross-sectional area of the iron core crossed by the lines of magnetic flux. In other words, when manufacturing a transformer with a constant capacity, if the core is made of a material with a large Bs, the cross-sectional area can be reduced, which means the transformer can be made smaller, and the coil can be wound with a wire of a predetermined diameter. We came up with the idea that if we made the iron core into a plate shape, it would be possible to make it thinner and removable, and we developed a transformer with the structure of the present invention.

That is, the thin transformer of the present invention includes a plurality of amorphous magnetic alloy thin bodies and at least one plate-shaped coil to which lead wires are connected, which are bonded and laminated with an electrically insulating adhesive. It is characterized by becoming.

The transformer of the present invention will be further explained based on the drawings. Fig. 1 is a perspective view of the transformer of the present invention, and Fig. 2 is a line AA' in Fig. 1.
In Figure 0, which is a longitudinal cross-sectional view taken along a line, 1 is a transformer block made of a thin amorphous magnetic alloy, and 2a and 2b are plate-shaped coils.

The transformer block 1 is made of a plate of an amorphous magnetic alloy, for example, a thin piece La shown in perspective views in FIGS. 3 to 5;
It is constructed by cutting out lb and lc, and combining these blocks by adhering and laminating each of these pieces through an adhesive. Here, in the figure, the width of the thin piece 1a indicated by Wa and the length of the thin piece 1b indicated by Lb are approximately equal, and the width of the thin piece IC indicated by Wc is the same as that of the thin piece 1a. Width Wa
smaller than

That is, the transformer block 1 is made by bonding and layering a predetermined plurality of thin pieces 1a to form two thin pieces blocks la'.
Thin pieces 1b are inserted on both sides of this block la'.
It consists of two blocks lb' made by gluing and laminating two blocks lb', and one block lc' (corresponding to a yoke) made by gluing and laminating a thin IC chip inserted approximately in the center of the whole. has been done.

Thus, a gallery-shaped space is formed in the approximate center of the transformer block 1 so as to surround the block lc'.In the transformer of the present invention, the primary coil and the secondary filter are arranged in this gallery-shaped space. The two plate-shaped coils 2a and 2b illustrated in FIGS. 6 and 7 are bonded with an insulating adhesive 3.
The lead wire 4 is disposed in a buried state, and a lead wire 4 is attached to the end thereof by, for example, welding or bonding with a conductive adhesive.
is connected.

The spaces between each thin body and between the thin body and the plate-shaped coil are bonded with an electrically insulating adhesive 1, for example, an organic synthetic resin such as epoxy resin, and the space between each thin body and the plate-shaped coil is bonded between each thin body and between the thin body and the plate-shaped coil. An electrically insulating layer is formed on the surface.

Here, the thin body serving as the iron core is made by punching, for example, a ribbon of an amorphous magnetic alloy manufactured by applying a normal liquid quenching method into a predetermined shape. Any alloy material may be used as the amorphous magnetic alloy as long as it has a large Os and a small iron loss in the high frequency range. For example, the following formula: C
o, FebM. An example is an amorphous alloy represented by Zd. Here, X represents at least one type of transition metal other than Fe and Go, and Z is an element necessary for amorphousization, such as Si,
B.

Represents one type selected from P, A4, and C,
a, b.

c and d each represent atomic %; C is O~10°; d is 15~30; the remainder is a, b; τT is 0.
Alloys with b of 04 to 0.08 exhibit particularly excellent magnetic properties, and alloys with b of 70 or more have Bs of 1000.
It has a high value of 0G or higher and is useful for downsizing transformers.

In addition, the thickness of the thin body is determined by the degree of iron loss in the high frequency range, v
Laws are set as appropriate in consideration of the relationship with single layer efficiency, but if it is too thin, the number of adhesive layers increases (increasing the number of insulating layers made of adhesive), leading to a decrease in lamination efficiency, and on the other hand, if it is too thick, high frequency For example, when the operating frequency is 20 to 500 KHz, the thickness should be 5 to 40 KHz, as this will lead to a decrease in magnetic properties.
It is preferable to set it within the range of μ. To adjust the thickness,
This can be easily achieved by appropriately selecting operating conditions such as the jetting speed of the melt and the rotational speed of the quenching drum in the liquid quenching method.

The plate-shaped coil is preferably made of copper, and can be easily manufactured by punching a thin copper plate into the shapes shown in Figures 6 and 7, or by etching methods used in the field of manufacturing semiconductor devices. can do.

The thus assembled transformer is put into use by molding its periphery with, for example, epoxy resin.

[Embodiments of the Invention] Ribbons (thickness 20-) of cobalt-based amorphous alloys represented by Go75.3Fea and 7Si4Bte were punched out to obtain thin pieces 1a, lb, and 1b shown in FIGS. 3 to 5, respectively. Obtained lc. The dimension of the thin piece 1a is 20. Ors width (Wa) 1
2.5 mg, and the dimensions of the thin piece 1b are width 2.5 mm and length (
Lb) 12.5mm, the dimension of the thin piece 1c is 8m-
The width (We) was 5.5m+*.

A block la' in which 125 thin pieces 1a are glued and laminated
Two blocks Ib' were formed by bonding and laminating 100 thin pieces 1b, and one block lc' was formed by bonding and laminating 100 thin pieces 1c. The thickness of the adhesive used was approximately 10p1゜thickness 150-
The plate-shaped coil shown in FIGS. 6 and 7 was manufactured from the copper sheet by etching.

:Figure 56 is the secondary coil (coil @1.0mm) 2
Figure 7 shows the primary coil (coil width 0).
．． 5mm) with 4 layers and 12 grains.

A sheet transformer was manufactured by combining the blocks of each of the thin pieces described above and incorporating a plate-shaped coil together with an insulating sheet. The terminals between the coils are joined to each other, and the other parts are insulated with an insulating sheet having a thickness of 50 IIJ.

The shape of the obtained transformer is 20.0 mm in length @ 12.5 mm.
The height IQ was 5mm. Install this transformer into a DC-DC converter.

Tested at 100KHz. As the primary voltage is 40V,
I was able to take out 12V-0.5A on the secondary side.

If a transformer with the same specifications as this transformer is made of ferrite, the effective cross-sectional area will be twice as large as the saturation magnetic flux density of ferrite is 45,000, and as a result, the outer dimensions of the sheet transformer will be 33mm long + 12mm wide. 5m
m height is 18.0 mm, and the volume is approximately three times larger.

[Effects of the Invention] As is clear from the above description, although the transformer of the present invention is thin and compact, it has a large capacity and does not generate heat due to iron loss in the high frequency range. It is effective as a commercial transformer and has great industrial value.

In addition, in the illustrated transformer, each of the thin bodies and plate coils has a rectangular cross section, but the shapes are not limited to this. Needless to say, it may be of any type.

[Brief explanation of drawings]

Fig. 1 is a perspective view of one example of the transformer of the present invention, and Fig. 2 is a perspective view of an example of the transformer of the present invention.
It is a longitudinal cross-sectional view along the AA' line of a figure. 3, 4, and 5 are all perspective views of thin pieces used in manufacturing the transformer of the present invention. 6 and 7 are top views of the plate coil. 1-trans block la, lb, lc-thin piece l
a', lb' + lc' Q body piece O-7ri 2a
, 2b-Plate coil 3-Insulating material 4-Lead wire Fig. 1C Fig. 2 Fig. 7

Claims (1)

[Claims] A thin transformer characterized in that a plurality of amorphous magnetic alloy thin bodies and at least one plate-shaped coil to which a lead wire is connected are bonded and laminated with an electrically insulating adhesive.