JP2005085786A - Common mode choke coil, its manufacturing process and common mode choke coil array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve adhesive properties of a magnetic substrate and to attain a degree of magnetic coupling substantially similar to that of a closed magnetic path and a high common impedance. <P>SOLUTION: In a common mode choke coil where an insulation layer and a coil pattern are formed alternately on a first magnetic substrate 1, each insulation layer is removed at least from the outer circumferential region of the coil pattern and a second magnetic substrate 12 is bonded through an adhesive layer 11, protrusions 14 having an adhesive forward end face are provided at the opposite end parts on the surface of the second magnetic substrate 12 facing the first magnetic substrate 1. The first and second magnetic substrates 1 and 12 are butted at the opposite end parts where the protrusions 14 are located to form outer shell parts at the opposite end parts. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a common mode choke coil, a manufacturing method thereof, and a common mode choke coil array, and more particularly to a filter used for suppressing a common mode current causing electromagnetic interference which is a problem in a balanced transmission system, and a manufacturing method thereof. Regarding the method.

  Conventionally, a laminated type is known as a chip-type common mode choke coil. This component has a structure in which a coil conductor pattern is formed on the surface of a magnetic material sheet such as ferrite and a first coil magnetic sheet forming a first coil and a similar second coil magnetic sheet are alternately laminated.

  Further, a common mode choke coil disclosed in Patent Document 1 below is known as one using a thin film construction method. In this component, a lead electrode is formed on a magnetic substrate by a thin film method, and then an insulating layer, a first coil conductor, an insulating layer, a second coil conductor, and an insulating layer are sequentially formed by using a thin film method, and the magnetic layer is formed from the upper surface. The structure is sandwiched between substrates.

  Moreover, in the common mode choke coil by the thin film method, as shown in Patent Document 2 below, the central part and the outer peripheral part of the insulating layer of the thin film method are etched in order to improve the magnetic coupling between the coils and increase the common impedance. In some cases, a closed magnetic circuit structure is formed by bonding (developing) the upper magnetic substrate with a resin obtained by mixing magnetic powder with an insulating material.

  Further, as in Patent Document 3 below, there is one in which the adhesion surface of the second magnetic substrate is formed in an uneven shape.

JP-A-8-203737 Japanese Patent Laid-Open No. 11-54326 JP 11-54327 A

  In the above conventional laminated type, there is a magnetic sheet between the first coil and the second coil conductor, and when used as a common mode choke coil, the magnetic coupling between the two coils is lowered, which causes a problem in characteristics. .

  The common mode choke coil by the thin film construction method of Patent Document 1 has a structure in which the first and second coil conductors are sandwiched between upper and lower magnetic substrates and does not have a closed magnetic circuit structure. There is a problem in that (It is difficult to increase the degree of magnetic coupling and common impedance).

  The thin film construction method of Patent Document 2 forms a closed magnetic circuit structure, so that the above problem is solved. However, a resin containing magnetic powder has low adhesiveness, which causes a problem in the adhesiveness of the magnetic substrate.

  As a countermeasure, it is possible to apply a magnetic powder-containing resin to the magnetic substrate adhesion side of the insulating layer containing the coil conductor and cure it, and then adhere the magnetic substrate with an adhesive. Shrinks and the magnetic powder containing resin embedded in the etched part of the insulating layer (where the central part and the outer peripheral part of the insulating layer are etched to form a closed magnetic circuit structure) shrinks, and only the adhesive layer (non-magnetic) above it It becomes thicker and the effect of increasing the common impedance is not so much obtained.

  In the thin film construction method of Patent Document 3, the above problem is solved as a structure close to a closed magnetic circuit, but since the first and second cores are separated from each other, a complete closed magnetic circuit structure is not obtained. There are still problems in terms of magnetic coupling and common impedance.

  In addition, when creating products with different common impedances, it is necessary to produce wafers with coil patterns suitable for each (insulation layers and multi-element coil patterns formed on a collective substrate). There were a lot of needs.

  In general, when trying to obtain a ferrite substrate with a thin and large area, the core is distorted, warped, and twisted during firing, and cracks and chips are also generated during grinding, making accurate processing difficult. It was.

  In view of the above points, the present invention provides a common mode choke coil that can improve the adhesion of a magnetic substrate and can obtain a magnetic coupling degree substantially the same as that of a closed magnetic circuit and a high common impedance, and its manufacture. It is an object to provide a method and a common mode choke coil array.

  Other objects and novel features of the present invention will be clarified in embodiments described later.

In order to achieve the above object, according to the first aspect of the present invention, an insulating layer and a coil pattern are alternately formed on a first magnetic substrate, and an insulating layer portion in the outer peripheral area of the coil pattern of each insulating layer is formed. In the common mode choke coil which is removed at least and the second magnetic substrate is bonded via the adhesive layer,
On the surface of the second magnetic substrate that faces the first magnetic substrate, convex portions whose tip surfaces are adhesive surfaces are formed at least at both ends, and the first and second magnetic substrates are: The outer shells are abutted at both end portions where the convex portions are located and closed at both end portions.

  A common mode choke coil according to a second aspect of the present invention is the common mode choke coil according to the first aspect of the present invention, wherein an insulating layer portion in a central region surrounded by the coil pattern of each insulating layer is removed, and the second magnetic substrate has the first portion. A convex portion located in the central region is formed on a surface facing one magnetic substrate, and a gap is provided between the tip surface of the convex portion located in the central region and the first magnetic substrate. It is characterized by being.

  A common mode choke coil according to a third aspect of the present invention is the common mode choke coil according to the second aspect, wherein the height of the convex portion located in the central region is adjusted based on the height of the convex portion formed at the both end portions. The common impedance value is adjusted.

According to the invention of claim 4 of the present application, an insulating layer and a coil pattern for a plurality of elements are alternately formed on a first magnetic substrate, and an insulating layer portion in the outer peripheral region of the coil pattern for the plurality of elements in each insulating layer is formed. In the common mode choke coil array in which at least the second magnetic substrate is bonded via an adhesive layer,
On the surface of the second magnetic substrate facing the first magnetic substrate, convex portions having tip surfaces as adhesive surfaces are formed at both ends, and the first and second magnetic substrates are It is characterized by forming an outer shell portion which is abutted at both end portions where the convex portions are located and closed at both end portions.

A method for manufacturing a common mode choke coil according to the invention of claim 5 of the present invention includes a film forming step of alternately forming an insulating layer and a coil pattern on the first magnetic substrate;
An etching step of removing at least the insulating layer portion of the outer peripheral region of the coil pattern of each insulating layer;
An adhesion step of adhering the second magnetic substrate to the first magnetic substrate via an adhesive,
On the surface of the second magnetic substrate facing the first magnetic substrate, convex portions having tip surfaces that are adhesive surfaces are formed at both ends. In the bonding step, the first and second magnetic substrates are formed. The magnetic substrate is abutted at both end portions where the convex portions are located, and has a closed outer shell portion at both end portions.

  The manufacturing method of the common mode choke coil according to the invention of claim 6 of the present application is the method according to claim 5, wherein, in the etching step, the insulating layer portion in the central region surrounded by the coil pattern of each insulating layer is also removed, A convex portion located in the central region is formed on a surface of the second magnetic substrate facing the first magnetic substrate, and a tip surface of the convex portion located in the central region and the first magnetic substrate are formed. It is characterized by providing a gap between the substrates.

  According to a seventh aspect of the present invention, there is provided a common mode choke coil manufacturing method according to the sixth aspect, wherein the height of the convex portion located in the central region is based on the height of the convex portion formed at the both end portions. And the size of the gap is adjusted.

  The method for manufacturing a common mode choke coil according to claim 8 of the present invention is the method of manufacturing the common mode choke coil according to claim 5, 6 or 7, wherein the second magnetic substrate is formed by grinding a ferrite substrate having a predetermined thickness with a slicer. The convex portion is formed by grinding the thickness thinly.

  According to the present invention, the adhesion between the first and second magnetic substrates is improved, and the first and second magnetic substrates are abutted with each other at both ends, and are in close contact with each other through the adhesive layer. Since the closed outer shell is formed at both ends, it is possible to realize a common mode choke coil and a common mode choke coil array that can obtain substantially the same magnetic coupling degree and high common impedance as a closed magnetic circuit. .

  Embodiments will be described below with reference to the drawings as the best mode for carrying out the present invention.

  1 and 2 show a first embodiment of the present invention, in which FIG. 1 is an exploded perspective view when a chip-type common mode choke coil is constructed, and FIG. 2 is an explanatory view showing a manufacturing process in section. In actual fabrication, a plurality of components are fabricated on the substrate at the same time. In this embodiment, description will be made for one element.

  As shown in these drawings, the chip-type common mode choke coil has an insulating layer 2, a first lead electrode layer 3, an insulating layer 4, a first coil conductor layer (spiral coil) on the main surface of the first magnetic substrate 1. Conductor pattern) 5, insulating layer 6, second coil conductor layer (spiral coil conductor pattern) 7, insulating layer 8, second lead electrode layer 9, insulating layer 10, adhesive layer 11 and second magnetic substrate 12 in this order. It is constructed by laminating and integrating.

  At this time, the first extraction electrode layer 3 and the first coil conductor layer 5, and the second extraction electrode layer 9 and the second coil conductor layer 7 are electrically connected through the through holes, respectively. One end of each lead electrode layer and one end of each coil conductor layer are connected to external electrodes (formed on the outer peripheral surface of the chip).

  The magnetic substrates 1 and 12 are sintered ferrite, composite ferrite, and the like, and the insulating layers 2, 4, 6, 8, and 10 are materials having excellent insulating properties such as polyimide resin and epoxy resin and good workability.

  The first magnetic substrate 1 may be a flat plate, but the second magnetic substrate 12 has irregularities on the surface 13 facing the first magnetic substrate 1. That is, the second magnetic substrate 12 includes an insulating layer and a coil pattern formed on the first magnetic substrate 1 by grinding a ferrite substrate having a predetermined thickness in advance with a high precision slicer using a grindstone such as a diamond wheel grindstone. Grind the thickness of the parts that are not required in the integration of the parts. As a result, a convex portion 14 whose front end surface is an adhesive surface is formed on one surface 13 of the second magnetic substrate 12, and at the center portion (located in the central region of the spiral coil conductor pattern as will be described later). Convex part 15 is formed in this. Then, the height of the convex portion 15 located at the center is ground (lowered) with reference to the height of the convex portion 14 formed at both ends, thereby assembling FIG. 2B described later. Sometimes, a magnetic gap G is formed between the first magnetic substrate 1 and the first magnetic substrate 1.

  The manufacturing procedure of the chip-type common mode choke coil is as follows. However, this is a case where the extraction electrode layers 3 and 9 and the first and second coil conductor layers 5 and 7 which are spiral coil conductor patterns are formed by vacuum film formation (evaporation, sputtering, etc.) or plating.

  An insulating layer 2 made of an insulating resin is formed on the first magnetic substrate 1. As a forming method, a spin coating method, a dip method, a spray method, or a printing method is employed. Thereafter, the insulating layer 2 is etched (developed) to remove the central region surrounded by the spiral coil conductor pattern and the outer peripheral region of the spiral coil conductor pattern.

  A metal film is formed on the insulating layer 2 using a vacuum film formation method or a plating method. The metal used is preferably Cu, Al or the like in terms of conductivity and workability. Thereafter, a pattern is formed and the extraction electrode layer 3 is formed. The patterning method is performed by an etching method using photolithography, an additive method (plating) using photolithography, or the like.

  Next, the method of forming the insulating layer 4 made of an insulating resin is the same as that of the insulating layer 2. At this time, a contact hole for connecting the extraction electrode layer 3 and the coil conductor layer 5 is formed simultaneously with etching of the center and outer peripheral area of the coil conductor pattern.

  Next, the first coil conductor layer 5 which is a spiral coil conductor pattern is formed. The construction method is the same as that of the extraction electrode layer 3.

  Next, an insulating layer 6 made of an insulating resin is formed. The construction method is the same as that of the insulating layer 2.

  In the same manner, the second coil conductor layer 7, the insulating layer 8 (insulating resin), the extraction electrode layer 9, and the insulating layer 10 (insulating resin), which are spiral coil conductor patterns, are sequentially formed.

  In this way, a film forming step of alternately forming an insulating layer made of an insulating resin and a conductor layer including a spiral coil conductor pattern on the first magnetic substrate 1, and a center surrounded by the coil conductor pattern of each insulating layer By performing the etching process of removing the insulating layer portion in the region and the outer peripheral region of the coil conductor pattern, a laminated body 20 in which the coil conductor pattern is built on the first magnetic substrate 1 is obtained as shown in FIG. Thus, the resin removing portion 21 (recessed portion) and the resin removing portion 22 (notched portion) from which the insulating layer has been removed are formed in the central region and the outer peripheral region of the laminate 20.

  Next, in the bonding step, the adhesive layer 11 is provided by applying an adhesive from the upper surface of the insulating layer 10. The second magnetic substrate 12 is a high-precision slicer in which a portion that becomes unnecessary in assembling the laminated body 20 composed of the insulating layer and coil pattern formed on the first magnetic substrate 1 in advance with respect to the ferrite substrate having a predetermined thickness. Since the concave pattern is formed (by this, the convex portion 14 is formed at both end portions and the convex portion 15 is formed at the central portion), the convex portions at both end portions are formed as shown in FIG. The tip surface (adhesion surface) of the portion 14 is abutted against the first magnetic substrate 1 via the adhesive layer 11, and the convex portion 15 in the central portion enters the resin removing portion 21 located in the central region of the laminate. Here, an epoxy adhesive is used as the adhesive layer 11, and the first magnetic substrate 1 and the second magnetic substrate 12 on which the laminate 20 composed of an insulating layer and a coil pattern is formed are pressed in an atmosphere of 150 ° C. It is cured while being integrated. Thereby, the 1st and 2nd magnetic substrates 1 and 12 can face | match at the both ends in which the convex part 14 was located, and can comprise the outer shell part closed in the said both ends.

  The above description is for one element, but in actuality, a plurality of elements are manufactured on the substrate simultaneously. After the substrate is cut into a one-element chip with a dicer, external electrodes are formed on the outer surface of the chip to complete a common mode choke coil.

  In the second magnetic substrate 12 used in this process, the height of the convex portion 15 at the center position is adjusted with reference to the height of the convex portions 14 at both ends, so that a gap G can be formed in the central portion. It is possible to adjust the resistance. That is, the common impedance can be adjusted by adjusting the height of the convex portion 15 at the center. This makes it possible to produce products with different impedances on wafers on which the same coil pattern (drawer conductor, spiral conductor) is formed. FIG. 3 shows an example (simulation) of the relationship between the gap amount and the common impedance in the same coil pattern product. However, the height of the convex portion 14 was 110 μm, and the thickness of the laminate 20 was also 110 μm. It can be seen that the common impedance changes greatly in the gap range of 0 to 50 μm.

  According to the first embodiment, the following effects can be obtained.

(1) The second magnetic substrate 12 is substantially the same as the closed magnetic circuit by being in close contact with the first magnetic substrate 1 via the adhesive layer 11 at two surfaces (adhesive surfaces of the convex portions 14 at both end positions). It is possible to obtain a magnetic coupling degree and a high common impedance.

(2) By adjusting the shape (height) of the convex portion 15 at the center of the second magnetic substrate 12 with reference to the convex portions 14 at both ends, different types of common impedance products of the same coil pattern formed wafer It can be made.

  4 and 5 show a second embodiment of the present invention in which a chip-type common mode choke coil array is manufactured. In this case, a plurality of elements of the coil pattern of the first embodiment are formed side by side on the first magnetic substrate 1. That is, a laminated body 20 composed of an insulating layer and a coil pattern for a plurality of elements is formed on the first magnetic substrate 1, and the first and second magnetic substrates 1 are surrounded by the laminated body 20 for the plurality of elements. , 12 are provided as outer shells. In addition, the same code | symbol is attached | subjected to the same part as the said Embodiment 1, or an equivalent part, and description is abbreviate | omitted.

  According to the second embodiment, the outer shell portion formed by abutting the first and second magnetic substrates 1 and 12 against the stacked body 20 for a plurality of elements is used in common, thereby reducing the size. be able to.

  FIG. 6 shows an embodiment in which a chip-type common mode choke coil array is manufactured according to the third embodiment of the present invention. In this case, convex portions 14 located at both ends of the surface 13 of the second magnetic substrate 12 facing the first magnetic substrate 1 are formed over the entire width of the second magnetic substrate 12. Other configurations are the same as those of the second embodiment.

  In this Embodiment 3, since the convex part 14 is formed over the full width of the 2nd magnetic substrate 12, the butt | matching area (adhesion area) of the 1st and 2nd magnetic substrates 1 and 12 can be enlarged, and magnetic coupling degree Can be further improved.

  Although the embodiments of the present invention have been described above, it will be obvious to those skilled in the art that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.

It is Embodiment 1 of this invention, and is an exploded perspective view in the case of comprising a common mode choke coil. It is explanatory drawing which shows the manufacturing process in the case of the said Embodiment 1 in a cross section. It is a graph which shows the relationship between the center part gap between 1st and 2nd magnetic substrates, and common impedance. It is Embodiment 2 of this invention, and is an exploded perspective view in the case of comprising a common mode choke coil array. It is sectional drawing in the case of the said Embodiment 2. FIG. It is Embodiment 3 of this invention, and is an exploded perspective view in the case of comprising a common mode choke coil array.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,12 Magnetic substrate 2,4,6,8,10 Insulating layer 3,9 Lead electrode layer 5,7 Coil conductor layer 11 Adhesive layer 14,15 Convex part 20 Laminated body 21,22 Resin removal part

Claims (8)

Insulating layers and coil patterns are alternately formed on the first magnetic substrate, and at least the insulating layer portion in the outer peripheral area of the coil pattern of each insulating layer is removed, and the second magnetic substrate is bonded via the adhesive layer. Common mode choke coil
On the surface of the second magnetic substrate facing the first magnetic substrate, convex portions having tip surfaces as adhesive surfaces are formed at both ends, and the first and second magnetic substrates are A common mode choke coil, characterized in that the outer shell portion is abutted at both ends where the convex portions are located and closed at both ends.   The insulating layer portion of the central region surrounded by the coil pattern of each insulating layer is removed, and the convex portion located in the central region is formed on the surface of the second magnetic substrate facing the first magnetic substrate. The common mode choke coil according to claim 1, wherein a gap is provided between a front end surface of a convex portion located in the central region and the first magnetic substrate.   3. The common mode according to claim 2, wherein a common impedance value is adjusted by adjusting a height of the convex portion located in the central region with reference to a height of the convex portion formed at the both end portions. choke coil. An insulating layer and a coil pattern for a plurality of elements are alternately formed on the first magnetic substrate, and at least an insulating layer portion in the outer peripheral area of the coil pattern for each of the plurality of elements in each insulating layer is removed, and an adhesive layer is interposed therebetween. In the common mode choke coil array to which the second magnetic substrate is bonded,
On the surface of the second magnetic substrate facing the first magnetic substrate, convex portions having tip surfaces as adhesive surfaces are formed at both ends, and the first and second magnetic substrates are A common mode choke coil array, characterized in that the outer shell portion is abutted at both end portions where the convex portions are located and closed at both end portions. A film forming step of alternately forming insulating layers and coil patterns on the first magnetic substrate;
An etching step of removing at least the insulating layer portion of the outer peripheral region of the coil pattern of each insulating layer;
An adhesion step of adhering the second magnetic substrate to the first magnetic substrate via an adhesive,
On the surface of the second magnetic substrate facing the first magnetic substrate, convex portions having tip surfaces that are adhesive surfaces are formed at both ends. In the bonding step, the first and second magnetic substrates are formed. The magnetic substrate is abutted at both ends where the convex portions are located, and forms a closed outer shell at both ends.   In the etching step, the insulating layer portion of the central region surrounded by the coil pattern of each insulating layer is also removed, and the central region is disposed on the surface of the second magnetic substrate facing the first magnetic substrate. 6. The method of manufacturing a common mode choke coil according to claim 5, wherein a convex portion is formed, and a gap is provided between a tip surface of the convex portion located in the central region and the first magnetic substrate.   The common mode choke coil according to claim 6, wherein the height of the convex portion located in the central region is ground with reference to the height of the convex portion formed at both end portions to adjust the size of the gap. Manufacturing method.   8. The common mode choke coil according to claim 5, wherein the second magnetic substrate is formed by grinding a ferrite substrate having a predetermined thickness with a slicer and grinding the thickness of an unnecessary portion thinly. 9. Manufacturing method.

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