JPH03263806A - Magnetic-core device - Google Patents

Abstract

PURPOSE:To enable use under severe conditions such as a high frequency or the like by suppressing a temperature rise due to an increase in the loss of a magnetic core by providing the following: a substrate formed of an insulating and good heat- conducting material; the magnetic core which is formed by laminating magnetic- substance sheets and which is installed so as to come into contact with the surface of the substrate; and a coil formed at the magnetic core. CONSTITUTION:The following are provided: a substrate 1 formed of an insulating and good heat-conducting material; a magnetic core 2 which is manufactured by laminating many magnetic-substance thin sheets and which has been installed so as to come into contact with the surface of the substrate 1; and a coil formed at the laminated magnetic core 2. For example, said substrate 1 is formed of a ceramic or the like such as aluminum nitride or the like; and the longitudinal size and the transverse size of the substrate 1 which is quadrangular are set to be large as compared with the diameter of the magnetic core 2. Said magnetic core 2 is formed by laminating and fixing many ring-shaped magnetic-substance sheets 3. A cobalt-based amorphous magnetic alloy, Permalloy or the like is used as a material for the magnetic-substance sheets 3. The magnetic core 2 is bonded and fixed to the surface of the substrate 1 by using a heat-resistant and insulating adhesive.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a magnetic core device.

(Prior Art) A magnetic core device in which a coil made of a conductive material is wound around a magnetic core made of a magnetic material is used as an inductance element or a transformer in electronic devices such as switching power supplies and communication circuits.

Conventionally, this magnetic core device has been constructed by winding a magnetic alloy strip to form a magnetic core, and in order to insulate this magnetic core from the outside, the magnetic core is housed in an insulating case made of insulating resin, or the entire surface of the magnetic core is A configuration is adopted in which the magnetic core is coated with an insulating resin, and then a fill conductor is wound around the outside of the insulating case housing the magnetic core, or a coil conductor is wound around the outside of the resin-coated magnetic core.

(Problems to be Solved by the Invention) However, such conventional magnetic core devices have the following problems.

That is, the magnetic core is housed in an insulating case made of insulating resin, or its surface is coated with resin, and the entire core is surrounded by an insulating member.

For this reason, the heat generated from the magnetic core is blocked by the insulating case or resin case that surrounds the entire magnetic core and is emitted to the outside, and is likely to remain inside the insulating case or resin case, resulting in very poor heat dissipation. Therefore, when the heat loss of the magnetic core is large and the heat generation temperature becomes high, the heat generating power cannot be sufficiently released to the outside, the temperature of the magnetic core increases, the characteristics of the magnetic core deteriorate, and the parts surrounding the magnetic core are adversely affected. There is a problem in that it becomes difficult to use a magnetic core to provide a magnetic core. This phenomenon is particularly noticeable when the magnetic core device is used under harsh conditions such as high frequencies, and it has been difficult to use the magnetic core device under such harsh conditions.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a magnetic core device that can be used under severe conditions such as high frequencies by suppressing the temperature rise caused by the increase in loss of the magnetic core.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the device of the present invention includes a substrate made of an insulating and highly thermally conductive material and a large number of magnetic thin plates. The magnetic core is characterized in that it includes a magnetic core that is created by overlapping each other and is provided on the substrate in contact with the surface of the substrate, and a coil that is provided on this laminated magnetic core.

The substrate used has an outer dimension larger than the outer dimension of the magnetic core according to method 1. Further, it is preferable to use a substrate made of a ceramic having good thermal conductivity or a metal insulated.

The magnetic core is preferably of a laminated type in which a large number of magnetic sheets are laminated.

A coil is a continuous conductor wire spirally wound around a laminated magnetic core, or a plurality of conductor patterns arranged on the surface of a substrate along the circumferential direction of the magnetic core, and a plurality of conductor patterns that connect adjacent conductor patterns. Use a conductor wire made of

(Function) The substrate made of an insulating and highly thermally conductive material serves as a heat sink that radiates heat generated by the magnetic core to the outside. Therefore, most of the heat generated in the magnetic core can be released to the outside through the substrate, thereby increasing the heat dissipation performance of the magnetic core.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the magnetic core device of the present invention.
This will be explained with reference to the figures.

This embodiment is directed to a magnetic core device applied to a choke coil.

In the figure, reference numeral 1 denotes a rectangular substrate, for example, and the substrate 1 is made of an electrically insulating and highly thermally conductive material. Specific materials for forming the substrate 1 include ceramics such as aluminum nitride, or metals subjected to insulation treatment. The vertical and horizontal dimensions of the rectangular substrate 1 are set to be larger than the diameter of the circular magnetic core 2, which will be described later. Reference numeral 2 denotes a magnetic core having a circular ring shape, and this magnetic core 2 is formed by stacking and fixing a large number of circular magnetic sheets 3. Specific materials for forming the magnetic sheet 3 include a cobalt-based amorphous magnetic alloy, permalloy, and the like. This magnetic core 2 is the substrate 1
It is arranged in the center of the substrate 1, and one side is in contact with the surface of the substrate 1, and is adhesively fixed to the surface of the substrate 1 using an insulating adhesive having viscosity resistance. Note that the entire surface of the magnetic core 2 except for the side surface that contacts the surface of the substrate is coated with an insulating resin. Further, a hole 4 is formed in a portion of the substrate surrounded by the magnetic core 2, and between the periphery of the hole 4 and the outer periphery of the substrate 1, a coil conducting wire 5 is inserted in the circumferential direction of the substrate, that is, the magnetic core 2. It is wound multiple times over the entire circumferential direction. That is, the coil conducting wire 5 is wound in one turn by straddling the magnetic core 2 provided on the substrate 1 between the periphery of the hole 4 of the substrate 1 and the outer periphery of the substrate 1, and the coil conducting wire 5 is wound in the same way.
A coil to be wound around the magnetic core 2 is constructed by continuously and spirally winding the entire circumferential direction of the substrate 1 . Note that terminals (not shown) are attached to both ends of the coil conducting wire 5 for connection to an external circuit.

In the magnetic core device configured in this manner, the substrate 1 is in contact with one side of the magnetic core 2, so that it functions as a heat dissipation plate through which heat generated by the magnetic core 2 is transferred and released to the outside. Since the substrate 2 is made of a material having good thermal conductivity, it can effectively conduct heat generated by the magnetic core 2 and release it to the outside. Since the substrate 1 has a larger area than the area where the magnetic core 2 contacts the substrate 1, the heat dissipation area of the magnetic core 2 is very large. Therefore, most of the heat generated in the magnetic core 2 is transferred to the substrate 1,
Further, it is conducted through the substrate 1 and released to the outside.

Due to the presence of this substrate 1, the heat dissipation of the magnetic core 2 is greatly improved, and the heat generated in the magnetic core 2 is effectively dissipated, so that the temperature rise due to heat generation of the magnetic core 2 can be suppressed. As a result, the magnetic core device can be used safely even under harsh operating conditions such as high frequency waves that generate a large amount of heat by suppressing temperature rise.

Another embodiment in which the magnetic core bag/placement of the present invention is applied to a choke coil will be described with reference to FIGS. 3 and 4.

In FIGS. 3 and 4, the same parts as in FIGS. 1 and 2 are designated by the same reference numerals.

In this embodiment, coils to be wound around a magnetic core 2 are arranged on the surface of a substrate 1 along the circumferential direction of the magnetic core 2, and are made of a plurality of conductor parts 6 made of an electrically conductive material. It is composed of a plurality of conductor wires 7 that connect things. At the location where the magnetic core 2 is placed on the surface of the substrate 1,
A plurality of conductor portions 6 that cross the outer circumferential side and the inner circumferential side of the magnetic core 2 are arranged and arranged at intervals in the circumferential direction of the magnetic core 2. The conductor portion 6 is formed, for example, by screen printing a conductive material in a predetermined pattern on the surface of the substrate 1, and then baking it. The conductor wire 7 is made of conductive metal and has a gate shape, and connects the magnetic core 2 between the outer circumferential side and the inner circumferential side at each position with an interval in the circumferential direction of the magnetic core 2 corresponding to each conductor part 6. The conductor portions 6 are arranged to straddle the conductor portions 6 and connect adjacent conductor portions 6 to each other. That is, both ends of each conductor part 6 protrude toward the outer circumferential side and the inner circumferential side of the magnetic core 2, and the substrate on which both ends of each conductor part 6 are located has a hole (2) penetrating in the thickness direction. (not shown) are formed respectively. One end of the conductor wire 7 disposed across the magnetic core is positioned at the end of the conductor portion 2 protruding toward the outer circumference of the magnetic core 2, and inserted into a hole formed in the substrate 1, and the other end is inserted into the hole formed in the substrate 1. The insert 6 and each conductor wire 7 are connected to a hole formed in the substrate 1 with the conductor portion 6 protruding toward the inner circumferential side of the magnetic core 2 at the end thereof. A coil is constructed by continuously winding the magnetic core 2 in a spiral manner in the circumferential direction.

According to this coil configuration, the length of the conducting wire is shorter than that of a coil made entirely of conductive material, and the effect of reducing resistance can be obtained.

The magnetic core device of this embodiment also has a high heat dissipation property like the magnetic core device of the above-described embodiment. Temperature rise due to heat generated by the magnetic core can be suppressed.

The magnetic core is not limited to a laminated type in which a large number of magnetic sheets are laminated, but may also be in a wound type in which a magnetic ribbon is continuously wound.

The structure in which the magnetic core is provided on the substrate is not limited to the structure in which the substrate is brought into contact with one side surface of the magnetic core, but it is also possible to have a structure in which a pair of substrates are brought into contact with both side surfaces of the magnetic core, for example.

The magnetic core device of the present invention can be applied not only to choke coils but also to devices such as oversaturated coils and transformers.

[Effects of the Invention] As explained above, according to the magnetic core device of the present invention, a substrate made of an insulating and highly thermally conductive material and a large number of magnetic thin plates are stacked on top of each other, and the surface of the substrate is Since the board is equipped with a magnetic core that is placed in contact with the magnetic core and a coil that is installed on this laminated magnetic core, the board acts as a heat sink that releases the heat generated by the magnetic core to the outside. Most of the heat can be effectively released to the outside through the substrate, thereby increasing the heat dissipation performance of the magnetic core. Therefore, the magnetic core device of the present invention can be used under severe conditions with large heat generation from the magnetic core, suppressing temperature rise in the magnetic core and maintaining high f≦condylarity.

[Brief explanation of drawings]

1 and 2 are views showing one embodiment of the magnetic core device of the present invention, and FIGS. 3 and 4 are views showing other embodiments of the magnetic core device of the present invention. 1... Board, 2... Magnetic core, 5... Coil conductor,
6... Conductor part, 7... Conductor wire.

Claims (4)

[Claims] (1) A substrate made of an insulating and thermally conductive material, a magnetic core made by stacking a large number of magnetic thin plates and provided in contact with the surface of the substrate, and a magnetic core provided on this laminated magnetic core. A magnetic core device characterized by comprising a coil. (2) The magnetic core device according to claim 1, wherein the substrate has an outer dimension larger than the outer dimension of the magnetic core. (3) The magnetic core device according to claim 1, wherein the coil is a continuous conductive wire wound helically around a laminated magnetic core. (4) Claim 1, wherein the coil is composed of a plurality of conductor patterns arranged on the surface of the substrate along the circumferential direction of the magnetic core, and a plurality of conductor wires connecting adjacent ones of these conductor patterns. The described magnetic core device.