JPH08236355A - Part for dc-dc converter - Google Patents

Abstract

PURPOSE: To enable a DC-DC converter part to be lessened in size and thickness and improved in characteristics by a method wherein second laminates are provided between first laminated bodies through the intermediary of an insulating layer, and lead wires are led out from the side faces of the second laminates. CONSTITUTION: Thin pieces 1a, 1b, and 1c are cut out from an amorphous magnetic alloy plate (as thick as 5 to 40μm). A transformer block 1 is composed of two thin piece blocks 1a' each formed of a prescribed number of the laminated and bonded thin pieces 1a and two thin piece blocks 1b' formed of a prescribed number of the laminated and bonded thin pieces 1b interposed on both the sides of the block 1a'. A prescribed number of the laminated and bonded thin pieces 1c are laminated and bonded into a thin piece block 1c' which is interposed at the center. Two plate-like coils 2a and 2b are provided as a primary coil and a secondary coil respectively in a corridor-shaped space located nearly at the center of the transformer block 1 as buried in an insulating adhesive agent, and lead wires 4 are connected to the ends of the coils 2a and 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact and thin DC
-Relating to parts for DC converter.

[0002]

2. Description of the Related Art DC-DC converter parts, such as transformers, have various ratings, but most of them have a substantially cubic shape.

Recently, in the field of electric and electronic equipment, there has been earnestly pursued to make the equipment light, thin, short and small. For example, when a transformer having a conventional structure is installed in the hybrid circuit, even if the hybrid circuit is sufficiently thin, And even if it has a small area, if the transformer is large compared to this circuit as in the past, it means that the dead volume occupied by the transformer in the whole circuit and equipment is large, and the whole is light and thin. It cannot be said that the efforts for shortening are satisfied.

Therefore, efforts to reduce the size and weight of circuits and equipment require the reduction of the thickness and size of DC-DC converter components as part of such efforts. Based on such a request,
A small transformer that uses a ferrite sintered body as an iron core has been developed. However, since the saturation magnetic flux density (Bs) of the ferrite sintered body is as small as around 4500 G, not only the core cannot be downsized sufficiently but also the thermal conductivity is low, so that there is a problem that the heat dissipation is poor.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a component for a DC-DC converter which is small in size, thin in shape, and has improved characteristics. To aim.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have found that DC-D
We paid attention to the fact that the capacity of C converter parts is proportional to the product of Bs of the iron core and the effective area of the iron core where the magnetic flux lines cross. That is, when manufacturing a component for a DC-DC converter having a constant capacity, if a material having a large Bs is used as an iron core, its cross-sectional area can be reduced, that is, DC-D.
Based on the idea that the C converter component can be downsized, and the coil can be formed into a plate shape instead of a winding of a predetermined diameter and the iron core can also be formed into a plate shape, the thickness can be reduced. D
We have come to develop parts for C-DC converters.

That is, according to the present invention (Claim 1), at least one plate-shaped coil and at least one plate-shaped coil are laminated with an insulating layer interposed between the first laminated body formed by laminating a plurality of amorphous magnetic alloy thin piece pieces. A second laminated body formed by laminating the second laminated body with an insulating layer interposed between the first laminated body, and the lead wire from the side surface of the second laminated body. Provided is a component for a DC-DC converter that is drawn out.

In the above DC-DC converter component, the amorphous magnetic alloy thin piece is of the general formula Co _a Fe _b M
_c Z _d (wherein M is at least one element of a transition metal other than Fe and Co, and Z is Si, B, P, Al, and C).
Showing at least one element selected from a, b,
c and d are each represented by atomic%, c is 0 to 10, d is 15 to 30, and the balance is a and b).

In this case, in the general formula Co _a Fe _b M _c Z _d , b / (a + b) is preferably 0.04 to 0.08. Further, b is preferably 70 or more. The thickness of the amorphous magnetic alloy thin piece is 5 to 40 μm.
It is preferably m.

The DC-DC converter component of the present invention will be described in detail below by taking a transformer as an example.

FIG. 1 is a perspective view of a transformer according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view taken along the line AA 'in FIG. 1 and 2, reference numeral 1 indicates a transformer block made of a thin body of an amorphous magnetic alloy, and 2a, 2a.
b shows a plate-shaped coil. The laminated state of the plate coils 2a and 2b is shown in a simplified manner in FIGS.

The transformer block 1 is obtained by cutting thin pieces 1a, 1b, 1c shown as perspective views in FIGS. 3 to 5, for example, from an amorphous magnetic alloy plate and bonding these pieces with an adhesive agent. -It is configured by combining each block formed by stacking. Here, in the drawing, a thin piece 1a indicated by Wa
And the length of the thin piece 1b indicated by Lb are substantially equal,
The width of the thin piece 1c indicated by Wc is smaller than the width Wa of the thin piece 1a.

That is, in the transformer block 1, a plurality of thin body pieces 1a are adhered and laminated in a predetermined number, and two thin body piece blocks 1a 'and two thin body pieces 1b are inserted on both sides of the block 1a'. Two blocks 1b ', which are formed by adhering and stacking
It is composed of one block 1c '(corresponding to a yoke) which is inserted at a substantially central position of the whole and is formed by adhering and laminating thin piece 1c.

Thus, a corridor-shaped space is formed in the transformer block 1 at a substantially central portion thereof so as to surround the block 1c '. The transformer according to the embodiment of the present invention has two plate-shaped coils 2a illustrated in FIGS. 6 and 7 as a primary coil and a secondary coil in this corridor-shaped space.
2b is embedded in the insulating adhesive 3,
The lead wire 4 is connected to the end portion by welding or bonding with a conductive adhesive, for example.

The thin bodies, and the thin body and the plate coil are bonded by an electrically insulating adhesive, for example, an organic synthetic resin such as an epoxy resin. And an electrical insulating layer are formed between them.

Here, the thin body to be the core is a ribbon of an amorphous magnetic alloy produced by applying a normal liquid quenching method, for example, punched into a predetermined shape. The amorphous magnetic alloy may be any alloy material having a large β and a small iron loss in a high frequency range. For example, an amorphous magnetic alloy represented by the following formula: Co _a Fe _b M _c Z _d Alloys may be mentioned.

In the formula Co _a Fe _b M _c Z _d , M is F
e, represents at least one kind of transition metal other than Co, and Z
Is an element necessary for amorphization, and represents one selected from Si, B, P, Al, and C, and a, b, c, and d each represent atomic%. c is 0 to 10, d is 15 to 30, and the balance is a and b, but b / (a + b) is 0.04.
Alloys of up to 0.08 exhibit particularly good magnetic properties.
Further, the alloy having b of 70 or more has a high Bs and is useful for downsizing the transformer.

The thickness of the thin body is appropriately determined in consideration of the degree of iron loss in the high frequency range and the stacking efficiency. However, if the thickness is too thin, the number of bonded sheets will be <(insulation made of an adhesive. (Increases the number of layers) causes a decrease in stacking efficiency
On the contrary, if it is too thick, the high-frequency magnetic characteristics will deteriorate, so
For example, when the operating frequency is 20 to 500 KHz, the thickness is preferably set within the range of 5 to 40 μm. The thickness can be easily adjusted by appropriately selecting the operating conditions such as the melt ejection speed and the rotation speed of the quenching drum in the liquid quenching method.

The plate coil is preferably made of copper, and a thin copper plate is punched into a shape as shown in FIGS. 6 and 7, or an etching method applied in the field of manufacturing semiconductor devices. It can be easily manufactured.

The transformer thus assembled is used by molding the periphery thereof with, for example, an epoxy resin.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically by showing Examples of the present invention.

Example 1 A ribbon of cobalt-based amorphous alloy represented by Co _75.3 Fe _4.7 Si ₄ B ₁₆ (thickness: 20 μm) was punched out, and each thin piece 1a, 1b, 1c shown in FIGS. Got Thin piece 1a
20.0 mm in length and 12.5 mm in width (Wa); thin piece 1b measures 2.5 mm in width and 12.5 m in length (Lb).
m; thin piece 1c has a length of 8 mm and a width (Wc) of 5.5 m
It was m.

Two blocks la 'in which 125 thin pieces 1a are adhered and laminated, two blocks lb' in which 100 thin pieces 1b are adhered and laminated, and further 100 thin pieces 1
Adhere c. Each of the laminated blocks lc 'was molded. The adhesive used had a thickness of about 10 μm.

A plate coil shown in FIGS. 6 and 7 was manufactured from a copper sheet having a thickness of 150 μm by an etching method. FIG. 6 shows a secondary coil (coil width 1.0 mm) with 4 layers and 2 turns, and FIG. 7 shows an example of a primary coil (coil width 0.5 mm) with 4 layers and 12 turns.

Combining the blocks of each thin piece described above,
A sheet transformer was manufactured by incorporating the plate coil together with an insulating sheet. The terminals between the coils are joined to each other, and the other portions are insulated with an insulating sheet having a thickness of 50 μm.

The shape of the obtained transformer has a length of 20.0 m.
m, width 12.5 mm, and height 10.5 mm.

The transformer was attached to a DC-DC converter and tested at 100 kHz. With the primary voltage of 40V, 12V-0.5A could be taken out on the secondary side. If a transformer with the same specifications as this transformer is made of ferrite, the saturation magnetic flux density of the ferrite is 4500G, so an effective area of double is required. As a result, the outer dimension of the sheet transformer is 33mm in length and width. 12.
The height is 5 mm and the height is 18.0 mm, which is about three times the volume.

Example 2 A ribbon of iron-based amorphous alloy represented by Co ₂ Fe ₇₇ B ₈ Si ₁₃ (thickness: 25 μm) was punched out to have the same dimensions as the thin piece 1a shown in FIG. 3 used in Example 1. 20.0 mm in length,
A thin piece having a width (Wa) of 12.5 mm was prepared, and five pieces of this piece were adhered and laminated to form two laminated bodies. As the plate-shaped coil, the 4-layer 12-turn coil shown in FIG. 7 used in Example 1 was used.

A plate-shaped coil was assembled together with an insulating sheet between two laminated bodies made of the amorphous alloy, and lead wires were pulled out from the side surfaces to manufacture a DC-DC converter component made of the sheet-shaped laminated body. The obtained part has a length of 20.
A very small and compact DC-DC converter component having 0 mm, a width of 12.5 mm and a height of 1.2 mm was obtained.

When this component was mounted on a 5V, 2A DC-DC converter and a mounting test up to 2A was conducted,
It was confirmed that superior characteristics of about 4 times were obtained compared to the case where parts having the same specifications were made of ferrite.

[0031]

As is clear from the above description, the DC-DC converter component of the present invention is thin and compact, but has a large capacitance and does not generate heat due to iron loss in a high frequency range. Therefore, it is effective as a component that is used by being attached to a DC-DC converter, and its industrial value is great.

In the illustrated DC-DC converter parts such as transformers, each thin body and plate coil have a quadrangular cross section, but the shape is not limited to this. Needless to say, the donut shape and the plate coil may have a mosquito coil shape.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a transformer according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA ′ of FIG.

FIG. 3 is a perspective view of a thin piece used when manufacturing a transformer according to an embodiment of the present invention.

FIG. 4 is a perspective view of a thin piece used when manufacturing a transformer according to an embodiment of the present invention.

FIG. 5 is a perspective view of a thin piece used when manufacturing a transformer according to an embodiment of the present invention.

FIG. 6 is a plan view of a plate coil used in the DC-DC converter component of the present invention.

FIG. 7 is a plan view of a plate coil used in the DC-DC converter component of the present invention.

[Explanation of symbols]

 1 ... Trans block la, lb, lc ... Thin piece la ', lb', lc '... Thin piece block 2a, 2b ... Plate coil 3 ... Adhesive 4 ... Lead wire

Claims (5)

[Claims] 1. A first laminated body formed by laminating a plurality of amorphous magnetic alloy thin body pieces, and a second laminated body formed by laminating at least one plate coil with an insulating layer interposed therebetween. Consists of
A DC-DC converter characterized in that the second laminated body is disposed between the first laminated body with an insulating layer interposed therebetween, and a lead wire is drawn out from a side surface of the second laminated body. Parts. 2. The amorphous magnetic alloy thin piece has the general formula Co
_a Fe _b M _c Z _d (wherein M is at least one element of a transition metal other than Fe and Co, and Z is Si, B, P, A
1 and at least one element selected from C,
a, b, c and d are each represented by atomic%, and c is 0 to 1
The component for a DC-DC converter according to claim 1, having a composition represented by 0, d is 15 to 30 and the rest are a and b. 3. The component for DC-DC converter according to claim 1, wherein b / (a + b) in the general formula Co _a Fe _b M _c Z _d is 0.04 to 0.08. . 4. The component for a DC-DC converter according to claim 1, wherein in the general formula Co _a Fe _b M _c Z _d , b is 70 or more. 5. The amorphous magnetic alloy thin piece has a thickness of 5-4.
DC- according to claim 1, characterized in that it is 0 μm.
DC converter parts.