JP3437428B2 - Trance - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a transformer in which an E core and an E core or an I core are bonded.

[0002]

2. Description of the Related Art Conventionally, small transformers mounted on a printed circuit board include a drum core transformer shown in FIG. 8A and a bobbin transformer shown in FIG. 8B.

In order to mount the drum core transformer of FIG. 8 (a) on a printed circuit board to make it thin, it is necessary to reduce the illustrated thickness t of the drum core and increase the length l. If t is made small and the length l is made too large, there is a limit to the formation of the ferrite core, and the length l cannot be made too large.

Further, in the bobbin transformer of FIG. 8B, the cross-sectional area of the coil portion is narrowed by the thickness of the bobbin. The configurations shown in FIGS. 8A and 8B will be briefly described below.

FIG. 8 shows an explanatory view of the prior art. FIG. 8A shows the structure of the drum core transformer. FIG. 8A-1 is a sectional view, and FIG. 8A-2 is an assembly view. The drum core transformer is manufactured by winding a coil around a ferrite drum core as shown in the drawing, inserting the coil into a ferrite ring core, and adhering the coil. In order to reduce the thickness of the drum core transformer, it is necessary to reduce the illustrated thickness t of the drum core and increase the length l, but it is not possible to form the drum core to have a too long l because of the ferrite core. It was

FIG. 8B shows the structure of the bobbin transformer. (B-1) of FIG. 8 shows a sectional view, and (b-) of FIG.
2) indicates a bobbin core. A coil is wound around a bobbin core made of an insulating material as shown in the figure, and this coil is inserted into a ferrite E core, and an I core is placed and bonded from above to obtain a product. In this bobbin transformer, since the coil is wound around the insulating core, the cross-sectional area of the portion around which the coil is wound is narrowed, and it was not possible to reduce the thickness when trying to make it thin.

[0007]

As described above, FIG.
In the drum core transformer of (a) and the bobbin transformer of (b) of FIG. 8, there is a problem that it is not possible to manufacture a thin (for example, several mm height) transformer having stable magnetic characteristics to be mounted on a printed circuit board.

In a bobbin transformer as shown in FIG. 8B, when an I-shaped core is placed on and bonded to an E-shaped core, they are made of sintered ferrite. The gap between the E-type core and the I-type core cannot be maintained at a desired value to obtain a predetermined magnetic resistance, and the magnetic characteristics vary, so that the center of the E core in (b-1) of FIG. There is also a problem that a troublesome work process of polishing the core and the I core so that the gap becomes a standard value and eliminating variations in magnetic characteristics is required.

The present invention solves these problems.
Insert an air-core coil in the E core and insert an insulating sheet or a thin film substrate between the core and the E core or the I core to bond them together, and when the thin film substrate is inserted, combine the coil on the thin film substrate. The purpose is to form a thin transformer with stable magnetic characteristics.

[0010]

Means for solving the problems will be described with reference to FIGS. 1 and 3. FIG. 1 and 3, the E core is a core of E-type ferrite or the like.

The I core is a core such as I type ferrite. The coil 1 is a coil formed on the thin film substrate 13. The coil 2 is a coil wound in advance with an air core.

The spacer 12 is a semi-cured resin sheet in which glass fibers having a predetermined thickness or spherical particles having a predetermined diameter are mixed. The thin film substrate 13 is a substrate having a predetermined thickness.

Next, the structure will be described. The coil 2 previously wound around the air core is put in the magnetic pole part in the center of the E coil, and the spacer 1
2 is placed, and the I core or E core is placed thereon, and the transformer is manufactured by applying pressure and heat to bond them.

Further, two sets of the coil 2 preliminarily wound around the air core are inserted into the central magnetic portion of the E core, and two sets are formed.
They are heated and bonded to produce a transformer.

Further, the I core is inserted into the hole formed in the substrate, the I core and the substrate in the vicinity of the I core are covered with an adhesive spacer 12 having a predetermined thickness, and the E core having the coil 2 inserted therein is opposed to the I core. It is arranged and glued to produce a transformer.

In these cases, the E core is covered with an adhesive spacer 12 on the surface of the substrate on the side opposite to the surface where the E core is adhered so as to connect the opposite surface of the substrate to the second substrate. I have to.

Further, the spacer 12 is a semi-cured resin sheet containing spherical particles having a predetermined diameter or a thin film substrate having a predetermined thickness so that the gap between the E core and the E core or the I core is stable. .

A portion without a core is provided on a part of the outer periphery of the E core of the thin film substrate 13, a thin film coil is formed in a portion where the cores do not face each other, and a thin film lead wire is formed from the portion without the E core to the outside. The gap is designed to be stable.

Therefore, an air-core coil is placed in the E core, and an insulating sheet or a thin film substrate is inserted between the E core and the E core or the I core to be adhered, and when the thin film substrate is inserted, it is placed on the thin film substrate. By forming the coil together, it is possible to manufacture a thin transformer with stable magnetic characteristics.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment and an operation of the present invention will be sequentially described in detail with reference to FIGS.

FIG. 1 shows a structural diagram of one embodiment of the present invention.
FIG. 1A shows an example using a prepreg. This is an example in which a prepreg is used as the spacer 12.
The prepreg is a sheet which is made into a semi-cured state by mixing glass fiber with a resin, or a sheet which is made into a semi-cured state by mixing spherical particles of a predetermined size with the resin.

FIG. 1A-1 shows the state immediately before pressurization / heating. In this state, the magnetic pole in the center of the E core
Coil 2 formed by winding a self-bonding wire around an air core in advance
Is placed, a prepreg is placed thereon, and an I core is further placed on the prepreg to be aligned.

FIG. 1A-2 shows the state immediately after pressurization and heating. In this state, the I core is heated by being pressed in the direction of the E core, so that the prepreg has a predetermined thickness and the E core and the I core are bonded at a predetermined position to form a transformer.

As described above, the gap distance between the E core and the I core is accurately formed by the size of the glass fiber or the spherical particles contained in the prepreg. Therefore, the gap distance when the transformer is made is set accurately and stable. It is possible to manufacture a transformer having the above magnetic characteristics.

FIG. 1B shows an example using a thin film substrate. This is an example in which the thin film substrate 13 is used as the spacer 12. The thin film substrate 13 is a thin flexible substrate having a predetermined thickness. In the illustrated state, a coil 2 formed by winding a self-bonding wire rod around an air core in advance is placed in the magnetic pole portion in the center of the E core, a thin film substrate 13 is placed thereon, and an I core is further placed thereon. It is possible to manufacture a transformer by placing and aligning, and bonding and fixing the whole by the adhesive material applied to the E core and the I core.

As described above, the gap between the E core and the I core is accurately formed according to the thickness of the thin film substrate 13. Therefore, the gap between the transformer and the core can be accurately set to manufacture a transformer having stable magnetic characteristics. It becomes possible to do.

Next, the manufacturing method of the tranulus having the structure of FIG. 1 will be described in detail in the order of the flowchart of FIG. FIG. 2 shows a manufacturing explanation flow chart of the present invention.

In FIG. 2, S1 manufactures an I core and an E core. This is to shape and fire ferrite powder,
An I core and an E core having a predetermined shape are manufactured. S2 manufactures an air-core coil. In this, a self-bonding wire is wound around a predetermined frame, self-bonded and taken out to manufacture the air-core coil 2.

At S3, a prepreg is manufactured. this is,
As described above with reference to FIG. 1A, a sheet in a semi-cured state in which glass fibers are contained in a resin or a semi-cured state in which spherical particles having a predetermined diameter are contained in a resin is manufactured.

In step S4, an air core coil is inserted in the E core. This is as shown in (a-1) of FIG.
The air-core coil 2 is inserted in the magnetic pole portion in the center of the E core. S5
Put a prepreg. This is as described above, for example, in FIG.
As shown in (a-1) of No. 1, a prepreg is placed on the E core.

In step S6, the I core is mounted. For this, as shown in (a-1) of FIG. 1 described above, the I core is placed on the prepreg. In S7, the position is adjusted. This is performed, for example, as shown in (a-1) of FIG. 1 described above, and then the E core and the I core are aligned.

In step S8, pressure and heat are applied. As described above, for example, as shown in (a-1) of FIG. 1, after alignment, the I core and the E core are pressurized and heated to make the prepreg a prescribed thickness and a gap interval to a prescribed value. And heat to cure the resin of the prepreg and bond it,
Manufacture transformers.

As described above, the air-core coil 2 is put in the magnetic pole portion in the center of the E core, the prepreg is placed on the coil 2, the I core is placed on the prepreg, the position is adjusted, and the E core is pressed and heated. By accurately setting the gap distance between the I and I cores to a specified value and bonding the E core and the I core, it is possible to manufacture a transformer with stable magnetic characteristics without variations in the gap distance.

FIG. 3 shows a structural diagram (1) of the present invention. This shows an example of a transformer in which a thin film substrate 13 having a predetermined thickness is put between the E core and the I core and bonded, and a thin film coil is formed on the thin film substrate 13.

FIG. 3A shows a side sectional view, and FIG. 3B shows a top sectional view. In FIGS. 3A and 3B, the E core is an E-type core, and here, in FIG.
As shown in (b) of FIG. 3B, the E core has side surfaces (upper side and lower side in the figure) cut.

The I core is an I type core, which is a rectangular core that can be placed exactly on the magnetic pole portion of the E core. The thin film substrate 13 is, as shown in the figure, inserted and bonded between the E core and the I core to set a prescribed gap interval, and is a thin film coil formed as the coil 1 shown in the figure. .

The coil 1 is a coil formed in a thin film on or in the thin film substrate 13, and a coil is formed in a thin film in a spiral shape in a portion of the E core having no magnetic pole portion. Similarly, the lead wire of the coil 1 is led to the outside from a portion of the E core where there is no magnetic pole portion. When a lead wire is provided in a portion of the E core having a magnetic pole portion, the lead wire causes the thickness of the thin film substrate 13 to be uneven, and as a result, the gap distance between the E core and the I core varies, and an accurate gap distance can be maintained. Is not possible, and the magnetic characteristics vary. In order to avoid this, the lead wire of the coil 1 is led to the outside from the portion of the E core where the magnetic pole portion is not present.

FIG. 4 is a structural diagram (2) of the present invention. This is because the E core shown in FIG. 3B has large notches on the upper side and the lower side in the figure, and the coil 1 is cut from this portion.
And the lead wire of the coil 2 is pulled out,
FIG. 4 shows an example in which the notch in the outer peripheral portion of the E core is very narrow.

FIG. 4A shows a case where the E core has a single notch in the outer peripheral portion and is narrow. In this case, as shown in the figure, both the coil 1 (thin film coil 1 formed on or in the thin film substrate 13 in FIG. 3) and the air core coil 2 are taken out from the cutout portion of the E core to the outside. As a result, as described above, the lead wires of the coils 1 and 2 are
When the lead lines of the coils 1 and 2 come between the magnetic pole portion of the E core and the I core without coming between the magnetic pole portion of the E core and the I core, the unevenness of the thin film substrate 13 is caused by the lead lines. It is possible to manufacture a transformer with stable magnetic characteristics by eliminating the variation in the gap distance due to. When the E core shown in FIG. 4A is provided with one notch, T = 1, 2,
It is possible to provide an arbitrary number of turns having an integer value of 3, ...

FIG. 4B shows a case where the E core has two notches in the outer peripheral portion and is narrow. In this case, as shown in the drawing, the coil 1 (thin film coil 1 formed on or in the thin film substrate 13 of FIG. 3) and the air-core coil 2 are both provided at the two cutouts of the E core. Take it out from the part. As a result, as described above, the lead wires of the coils 1 and 2 do not come between the magnetic pole portion of the E core and the I core, and the lead wires of the coils 1 and 2 and the magnetic pole portion of the E core do not. It is possible to manufacture a transformer with stable magnetic characteristics by eliminating variations in the gap distance due to the unevenness of the thin film substrate 13 due to the lead wire when coming to the I core. When two cutouts are provided in the E core of FIG. 4B, the number of turns of T = 0.5, 1, 1.5, ... Can be provided.

FIG. 5 shows a structural diagram (3) of the present invention. FIG. 5 shows an example of a transformer in which two sets of E cores are aligned and bonded to both sides of the thin film substrate 13 so as to face each other, and an air-core coil 2 inserted in a magnetic pole portion at the center of the E core,
The two sets of the coils 3 can be largely insulated, and since the E cores are arranged on both sides of the thin film substrate 13, the heights protruding from the thin film substrate 13 are equal on both sides, and as a result, the protruding heights are increased. Is about half,
It becomes possible to reduce the thickness. Further, as shown in (a) of FIG. 3 described above or on the thin film substrate 13, the coil 1 is similarly formed by a thin film coil. This allows
Three sets of coil 1, coil 2 and coil 3 will be formed.

FIG. 6 shows a structural diagram (4) of the present invention. This is done by making the thickness of the I-core approximately the same as the thickness of the sub-board 14 and putting the I-core in the hole formed in the sub-board 14 to make it substantially flat, and then making the prepreg sheet 15 of FIG. Wrap the I-core and the perimeter of the sub-board 14 with holes so that the coil 2 is placed on the E-core and put on it, pressurize and heat to bond, and mount the transformer on the sub-board 14. It was done.

As a result of the above, the portion of the I core in the transformer consisting of the I core and the E core containing the coil 2 is just inserted in the hole of the sub-board 14, and the height is reduced by the height of this I core. It becomes possible to do. At this time, the lower surface of FIG. 6 is actually the FPC1 as shown in FIG.
8 is mounted with a sheet 15 adhered thereto.

FIG. 7 is a structural diagram (5) of the present invention. This is because the I core inserted in the hole of the sub-board 14 shown in FIG. 6 and the E core containing the coil 2 are accurately set to the specified gap interval with the sheet 15 interposed therebetween.
The surface on the opposite side (lower side in the figure) of the core is mounted on an FPC (flexible printed circuit board) 18 with a sheet 15 adhered thereto. Other components can be mounted on the FPC 18,
Further, side terminals are provided as shown at the left end and the right end, and the whole is soldered and mounted on the main board 17.

As described above, the I-core is inserted into the hole of the sub-board 14 and the sheet 15 is wound around the outer periphery of the coil 15 and the coil 2 is placed on the upper side in the drawing.
Place the E-core containing the above, and contact the FPC 18 on the lower side, pressurize and heat from the top and bottom to solidify and bond the sheet 15, and accurately set the gap distance between the I-core and the E-core to a specified value. At the same time, it can be mounted on the FPC 18 together with the sub-board 14. Further, the left and right side terminals of the FPC 18 are put into the large cutouts of the main board 17 and soldered as shown in the figure, and the upper side of the transformer is set to substantially the same height as the upper side of the main board 17. The lower side is a portion thicker than the thickness of the main board, and in the figure, the transformer can be mounted only by protruding to the lower side by the same thickness as the sub-board 14, and the conventional transformer is surface-mounted on the main board 17. The height of the protruding portion is made extremely low (about half) and the thickness is reduced, and the gap between the I core and the E core is set accurately by the seat 15 (for example, the prepreg described above). Therefore, it is possible to manufacture and mount a stable transformer with no variation in magnetic characteristics.

[0046]

As described above, according to the present invention,
An air-core coil is put in the E core, and an insulating sheet or a thin film substrate is put between this and the E core or the I core to be bonded, and when the thin film substrate is put, the coil is also formed on the thin film substrate. Since such a structure is adopted, a thin transformer with stable magnetic characteristics can be manufactured. With these, (1) when the core is made of ferrite, the core can be easily molded, the magnetic resistance can be reduced, and the transformer can be thinned.

(2) The gap spacing between the cores can be formed easily and reliably without variation, and the saturated magnetic characteristics of the transformer can be stabilized. (3) By using a thin film substrate having a predetermined thickness for forming the gap, it is possible to mount a component on the thin film substrate together, mount a transformer and a component together, and realize an integrated circuit board. It can be further mounted in the hole to achieve overall thinning.

[Brief description of drawings]

FIG. 1 is a structural diagram of one embodiment of the present invention.

FIG. 2 is a manufacturing explanatory flowchart of the present invention.

FIG. 3 is a structural diagram (1) of the present invention.

FIG. 4 is a structural diagram (2) of the present invention.

FIG. 5 is a structural diagram (3) of the present invention.

FIG. 6 is a structural view (No. 4) of the present invention.

FIG. 7 is a structural view (No. 5) of the present invention.

FIG. 8 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

12: Spacer 13: Thin-film substrate 14: Sub-substrate 15: Sheet 17: Main substrate 18: FPC Coil 1: Thin-film coil coil 2 formed in or on the thin-film substrate 13, 3: Air-core coil I wound with wire rod Core: I type core E core: E type core

Claims (6)

(57) [Claims] 1. A transformer in which an E core and an E core or an I core are bonded together, an E type E core, a coil wound in advance on an air core and placed in a central magnetic part of the E core, and the E core. Place the thin film coils of the specified thickness, facing each other.
E core or I for inserting and bonding the formed thin film substrate
A transformer having a type I core. 2. A transformer in which an E core and an E core are bonded together, an E type E core, a coil wound in advance on an air core and placed in a central magnetic portion of the E core, the E core and the E core. A transformer, characterized in that the thin film substrates each having a predetermined thickness and formed with a thin film coil are inserted and adhered to each other. 3. A transformer in which an I core and an E core are bonded together, an E type E core, a coil wound in advance on an air core and placed in a magnetic part at the center of the E core, and a thickness substantially equal to a thickness of a substrate. I type I core and the above I core in a hole formed in the substrate, and the I core and the substrate near the I core are covered with an adhesive spacer.
A transformer characterized in that the E-core containing the coil is bonded to face each other. 4. The E-core according to claim 3 is covered with the adhesive spacer together with the surface of the substrate on the opposite side to which the E-core is adhered to face to face, and the opposite surface of the substrate is aligned with the second substrate. A transformer characterized by being connected by. 5. The transformer according to claim 3 , wherein the spacer is a semi-cured resin sheet containing an insulator having a predetermined diameter or a thin film substrate having a predetermined thickness. 6. A coreless portion is provided on a part of the outer periphery of the E core of the thin film substrate, a thin film coil is formed in a portion where the cores do not face each other, and a thin film lead wire is provided outside the E core-free portion. The transformer according to claim 5, which is formed.