JP3476906B2 - Multilayer inductor substrate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated structure comprising a ceramic layer or a layer of a magnetic material, a coil formed by a coil pattern disposed between the layers, and an internal wiring. More particularly, the present invention relates to a multilayer inductor excellent in preventing leakage magnetic flux from flowing in a side direction of a coil. 2. Description of the Related Art In general, an inductor component is formed by winding a conductor wire coated with an insulating material around a core member, housed in a shield case, and mounted on a predetermined printed wiring board. Recently, there has been a multilayer inductor to which a multilayer ceramic technology is applied in accordance with a demand for downsizing of a mounting device such as an electronic device. In this structure, in a laminated body composed of a plurality of ceramic layers, a coil pattern is formed between each of the ceramic layers, and a via hole conductor is formed in each ceramic layer, and a coil is formed by the plurality of coil patterns and the via hole conductor. At the same time, there is a laminated inductor substrate in which a predetermined circuit is achieved by forming an internal wiring serving as a predetermined circuit between each ceramic layer and forming a via hole conductor in each ceramic layer (Japanese Patent Laid-Open No. 63-29910).
No.). Further, as a method of preventing the above-described leakage magnetic flux of the coil, the present applicant has previously disclosed a laminated inductor in which, for example, four via-hole conductors are formed around the coil in the laminating direction of the laminated body. Proposed. In this laminated inductor, as shown in FIG. 6, for example, a laminated body 80 is composed of, for example, nine ceramic layers 8.
1a to 81f, 81x, and 81y, and a predetermined number of turns, for example, one-turn coil patterns 82a to 82 between each of the ceramic layers 81x and 81a to 81f.
f are arranged, and further, the ceramic layers 81a to 81
In 1e, via-hole conductors 83a to 83e for connecting the other ends of the coil patterns 82a to 82e and one ends of the coil patterns 82b to 82f are formed. Thus, a series of coils is achieved from one end of the coil pattern 82a to the other end of the coil pattern 82f. In order to prevent the leakage magnetic flux from the coil, for example, short-circuit conductor films 84x and 84y are formed on the ceramic layers 81x and 81y, and the respective ceramics 81x and 81y are formed.
Via hole conductors 85a to 85d that connect the short-circuit conductor films 84x and 84y are formed around a to 81f. Thus, four closed loop circuits are formed around the coil by the short-circuit conductor films 84x and 84y and the via-hole conductors 85a to 85d. [0008] Here, in a laminated inductor substrate in which a predetermined circuit network is provided in the laminated inductor, for example, the coil is used as a transformer, although it depends on the characteristics of the coil and the configuration of the circuit. When used, a large number of coil patterns are required for the number of laminated coil patterns for achieving a predetermined coil and the number of laminated internal wirings necessary for forming a predetermined circuit network. In such a case, the short-circuit conductor films 84x, 84
y, the opening of the closed loop circuit composed of the via-hole conductors 85a to 85d becomes large, so that the leakage magnetic flux from the coil cannot be sufficiently changed into a current in the closed loop circuit, and a small amount of leakage magnetic flux is generated. Had occurred. As a result, it is conceivable that the predetermined circuit network is adversely affected, and the operation of the predetermined circuit is malfunctioned. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to completely reduce leakage magnetic flux from a coil when integrating the coil and a predetermined circuit network into a laminate. An object of the present invention is to provide a multilayer inductor substrate capable of achieving a highly reliable circuit operation by shutting off. According to the present invention, there is provided a laminated inductor substrate according to the present invention, comprising: a laminated body formed by laminating a plurality of ceramic layers or magnetic layers; a coil pattern disposed between the layers; In a laminated inductor substrate including a coil formed of via-hole conductors for connecting patterns and a predetermined circuit network including internal wiring disposed in each layer, a conductor pattern disposed between different layers around the coil. A plurality of closed-loop circuits formed by connection with via-hole conductors formed at both ends of the conductor pattern are arranged in the stacking direction such that the conductor pattern is located between all layers where the coil pattern exists. It is. According to the present invention, a closed loop circuit comprising a conductor pattern disposed between different layers and a via-hole conductor connecting both ends of the conductor pattern is formed around a coil disposed in a plurality of laminated ceramic layers. A large number of the conductor patterns are arranged in the stacking direction so as to be located between all the layers where the coil patterns exist. Therefore, the leakage magnetic flux of the coil around the coil can be effectively cut off by the plurality of closed loop circuits arranged in the stacking direction, which has a bad influence on a circuit network formed in the same stack. And a stable circuit operation is possible. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a laminated inductor substrate according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view of the laminated inductor substrate of the present invention, FIG. 2 is a sectional view, and FIG. 3 is an exploded perspective view of a coil portion of the laminated body. In FIG. 1, a laminated inductor substrate 10
Is composed mainly of a laminate 1 in which a plurality of ceramic layers or magnetic material layers are laminated, and a surface wiring 2 including terminal electrodes and connection pads on the main surface of the laminate 1 as necessary.
And electronic components 30 such as chip-shaped electronic components, lead-type electronic components, and IC chips. In the embodiment, in order to improve the coil characteristics, a through hole 11 is formed at the center of the coil of the laminated body 1, and the through hole 11 is formed of substantially E-shaped members 40a and 40b from above and below in the laminating direction. The core member 40 is arranged. As shown in FIGS. 2 and 3, the laminate 1 is made of an insulating ceramic such as alumina or a magnetic material (ceramic in a broad sense) such as Mn / Zn ferrite and a glass component added as necessary. Containing ceramic layers 1a-1g
Are stacked, and between the ceramics 1a to 1g layers, coil patterns 2b to 2g, which constitute coil components,
Internal wiring 8 constituting a predetermined circuit connected to this coil
... are arranged. In FIG. 3, the internal wirings 8 between the ceramic layers 1c to 1g are omitted. The laminated body 1 has a through hole 11 formed in the center axis of the coil component, and a core member 40 formed by combining two E-shaped members 40a and 40b in the through hole 11 is disposed. . The coil components include the ceramic layers 1a and 1a.
b, coil patterns 2 arranged in 1b and 1c...
, 2c... and via-hole conductors 3b to 3f penetrating the ceramic layers 1b to 1f. That is, the other end of the coil pattern 2b is connected to one end of the coil pattern 2c via the via hole conductor 3b, and the other end of the coil pattern 2c is connected to the via hole conductor 3b.
c, the other end of the coil pattern 2d is connected to one end of the coil pattern 2e via the via-hole conductor 3d, and the other end of the coil pattern 2e is connected to the other end of the coil pattern 2e.
Is connected to one end of a coil pattern 2f via a via-hole conductor 3e, and the other end of the coil pattern 2f is connected to one end of a coil pattern 2g via a via-hole conductor 3f. Thus, a coil having a predetermined number of turns is achieved from one end of the coil pattern 2b to the other end of the coil pattern 2g. One end of the coil pattern 2b and the other end of the coil pattern 2g are connected to an internal wiring 8 constituting a circuit of the laminated body 1, or are led out to the main surface of the laminated body to form a surface wiring 20 or the like. Connected to. The network comprises each of the ceramic layers 1a and 1b, 1
, and via-hole conductors 9 connecting the respective internal wirings 8 according to a predetermined circuit network. Further, a part of the internal wirings 8 is formed. Are connected to the surface wiring 20 on the main surface of the laminate 1 and the like. Here, the characteristic features of the present invention are that the coil components composed of the coil patterns 2b to 2g, the via-hole conductors 3b to 6g and the internal wiring 8,.
··· a predetermined circuit network, that is, around the coil component, two opposite sides in the figure, conductor patterns 4b to 4g,
5b to 5g and a plurality of, for example, five closed loop circuits composed of via-hole conductors 6a, 6b, 7a and 7b are arranged in the stacking direction.
5b to 5g are located between all the layers where the coil patterns 2b to 2g exist. For example, the conductor patterns 4b and 4c on one side are connected to the via-hole conductors 6a and 6b at both ends.
To form a first closed loop circuit, and connect the conductor pattern 4c and the conductor pattern 4d at both ends with via-hole conductors 6a and 6bc to form a second closed loop circuit. The pattern 4e is connected at both ends to via-hole conductors 6a and 6b to form a third closed loop circuit, and the conductor pattern 4e and the conductor pattern 4f
Are connected to the via-hole conductors 6a and 6b at both ends to form a fourth closed loop circuit. The conductor pattern 4f and the conductor pattern 4g are connected to the via-hole conductors 6a and 6b at both ends.
To form a fifth closed loop circuit. The other side of the coil similarly forms five closed loop circuits by the conductor patterns 5b to 5e and the via-hole conductors 7a and 7b. In FIG. 2, the conductor patterns 4b to 4b
e, the closed loop circuit group formed by the via-hole conductors 6a and 5b is denoted by "4", and the conductor patterns 5b to 5b
e, a closed loop circuit group formed by the via-hole conductors 7a and 7b is denoted by "5". It is desirable that any of the closed loop circuits be connected to the ground potential of the internal wiring 8. As another structure, as shown in FIG. 4, the above-mentioned coil patterns 2a to 2b (generally referred to as 2) are arranged between the ceramic layers 1a to 1g. 1b and the conductor pattern 41
b, 51b are connected to the conductor patterns 41c to 41f, 42c to 42f, 5
1c to 51f, 52c to 52f are replaced with ceramic layers 1b to
Conductor patterns 41g and 51g are respectively arranged in 1f. In addition, the conductor patterns 41b to 4b of the ceramic layers 1b to 1f
1g, 42c to 42f, 51b to 51g, 52c to 51
f, via-hole conductors 61b to 61f, 62b to 62f, 71 penetrating through the thickness of ceramic layers 1b to 1f.
b-71f and 72b-72f are formed. Thus, on one side of the coil, the conductor pattern 41b and the conductor pattern 41c are connected at both ends to the via-hole conductors 61b and 62b to form a first closed loop circuit, and the conductor pattern 42c and the conductor pattern 42d Are connected at both ends to via hole conductors 61c and 62c to form a second closed loop circuit, and the conductor pattern 41d and the conductor pattern 41e are connected at both ends to via hole conductors 61d and 62d to form a third closed loop. A fourth closed loop circuit is formed by connecting a conductor pattern 42e and a conductor pattern 42f at both ends thereof to via hole conductors 61e and 62e to form a fourth closed loop circuit. 61
f, 62f to form a fifth closed loop circuit. Incidentally, the other side of the coil is also a conductor pattern 51.
b to 51g, 52c to 51f and via-hole conductor 71b
To 71f and 72b to 72f constitute five closed loop circuits. Further, as another structure, as shown in FIG. 5, the above-mentioned coil patterns 2a to 2b (generally referred to as 2) are arranged between the ceramic layers 1a to 1g, and the ceramic layers 1a to 1g are arranged. 1g between the conductor pattern 43
b-43g, 53b-53g, and the conductor patterns 43b-43g, 53b of the ceramic layers 1b-1f.
Via-hole conductors 63a to 63c at both ends of
64a to 64c, 73a to 73c, and 74a to 74c are formed. Thus, for example, three closed loop circuits are formed on one side of the coil. That is, a first closed loop circuit is formed by the conductor patterns 43b and 43d, and the through-hole conductors 63a and 64a that penetrate through the thickness of the ceramic layers 1b and 1c connecting both ends of the conductor patterns 43b and 43d. ,
A second closed-loop circuit is formed by the through-hole conductors 63b and 64b, which penetrate the ceramic layers 1c, 1d and 1e, and connect the conductor patterns 43e and 43g, and the ceramic layer 1 connecting both ends thereof.
e, via-hole conductors 63c, 64c that pass through the thickness of 1f
Constitute a third closed loop circuit. Incidentally, also on the other side of the coil, three closed loop circuits are formed by the conductor patterns 53b to 53g and the via hole conductors 73a to 73c, 74a to 74c. 4 and 5
In the figure, the through-hole in which the core member 40 is arranged, the internal wiring for achieving a predetermined circuit, and the surface wiring 20 are omitted. In FIG. 3 to FIG. 5 described above, in FIG. 3, five closed loop circuits are arranged in the laminating direction by the thickness of each ceramic layer 1b to 1g, and the conductor patterns 4b to 4g,
5b to 5g are shared, and in FIG.
Five closed loop circuits are formed in the stacking direction by the thickness of b to 1 g, and the conductor patterns 41b to 41g and 42c to 42
f, 51b to 51g, and 52c to 52f are independent. In FIG. 5, a plurality of closed loop circuits are formed in the stacking direction by the thickness of a plurality of layers, two layers, or three layers, and the closed loop circuits overlap each other. ing. As described above, the coil patterns 2b to 2g
Since a plurality of closed loop circuits are arranged in the stacking direction of the multilayer body 1 around the coil composed of the above, the opening of the closed loop circuit can be reduced, and the leakage magnetic flux generated from the coil component can be effectively prevented. be able to. This does not affect the predetermined network composed of the internal wirings 8..., And can be said to be an extremely effective structure especially in a laminated inductor substrate in which a predetermined circuit is combined with a multilayer inductor. . As a method for manufacturing the multilayer inductor substrate as described above, any of the well-known methods used for manufacturing a multilayer ceramic substrate can be applied. The most common green sheet multi-layer method will be described briefly using the laminate of FIG. 3 as an example. First, a ceramic powder such as alumina or various ferrites (a ferrite sintered body is broadly referred to as a ceramic in the present invention) and, if necessary, a solid component of a glass frit are mixed with an organic vehicle or the like to form a slip material.
A tape is formed by a doctor blade method or the like, and a green sheet having a predetermined shape is created. Thereafter, the green sheets corresponding to the ceramic layers 1b to 1f are provided with via-hole conductors 3b to 3f, depending on the structure of the coil structure, the predetermined circuit structure, and the closed loop circuit.
Through holes 6a, 6b, 7a, 7b, 9 are formed by punching. Next, while filling and printing a conductive paste into the through holes formed in the green sheets corresponding to the ceramic layers 1b to 1f, coil patterns 2b to 2d and conductive patterns 4b to 4g, 5b are formed on each green sheet. ~ 5
g, a conductive film to be the internal wiring 8... is formed by printing a conductive paste. The green sheets serving as the ceramic layers 1a and 1g are provided with via-hole conductors according to the connection between the internal wiring 8 and the surface wiring 20, and according to the connection between the coil patterns 2a and 2g and the surface wiring 20. Is formed, and the conductive paste is filled. The green sheets thus obtained are laminated and pressed in consideration of the lamination order of the ceramic layers 1a to 1g. In addition, while forming the dividing groove so as to have the shape of the final laminated inductor substrate, if necessary,
A through-hole in which the core member is disposed on the center axis of the coil is formed by press molding. Next, a baking process is performed. The firing treatment includes a binder removal step and a sintering step. Thereafter, if necessary, the surface wiring 20 is formed by a baking process, divided into a predetermined shape, and the electronic component 30 and the core member 40 are mounted and mounted. In the above embodiment, the closed loop circuit is formed on two opposing sides around the coil.
It may be formed on each of the four sides so as to surround all the coils. Also, in the above-described embodiment, one
Although one coil is formed, a plurality of coils may be formed, and these may be combined as a transformer component by a core member. Further, by using a fired ceramic substrate as the support substrate, the support substrate can be used as a part of the laminate without peeling the laminate from the support substrate. In this case, a coil pattern may be formed in advance on the surface of the fired ceramic substrate. As described above, according to the present invention, the leakage magnetic flux generated from the coil can be cut off by the closed loop circuit, and the predetermined circuit network including the internal wiring arranged in the same laminated body is adversely affected. And a stable circuit operation is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of a multilayer inductor substrate according to the present invention. FIG. 2 is a sectional view of a multilayer inductor substrate according to the present invention. FIG. 3 is an exploded perspective view of the laminated body in FIG. FIG. 4 is an exploded perspective view of a multilayer body of another multilayer inductor substrate of the present invention. FIG. 5 is an exploded perspective view of a laminated body of another laminated inductor substrate of the present invention. FIG. 6 is an exploded perspective view of a multilayer body of a conventional multilayer inductor component. DESCRIPTION OF SYMBOLS 1 ... Laminated bodies 1a-1g ... Sheets 2b-2g ... Coil patterns 3b-3f ... Via hole conductors 4b-4g, 5b-5g ... Conductor patterns 6a, 6b, 7a, 7b: Via-hole conductors 41b to 41g, 42c to 42f, 51b to 51g, 52c to 52f
Conductor patterns 61b to 61f, 62b to 62f, 71b to 71f, 72b to 72f
..Via hole conductors 43b to 43g, 53b to 53g: conductor patterns 63a to 63c, 64a to 64c, 73a to 73c, 74a to 74c
..Via hole conductor 8 ... Internal wiring 9 ... Via hole conductor

Claims (1)

(57) [Claims 1] A via hole for connecting a coil pattern disposed between each layer and a coil pattern formed on each layer to a laminated body formed by laminating a plurality of ceramic layers or magnetic layers. In a laminated inductor substrate including a coil made of a conductor and a predetermined circuit network including internal wiring arranged in each layer, a conductor pattern disposed between different layers and both ends of the conductor pattern are arranged around the coil. the closed loop circuit formed by the connection between the formed via-hole conductors, the coil
Place the conductor pattern between all layers where patterns exist.
Laminated inductor substrate wherein a plurality placed to the stacking direction so as to location.