The present application claims priority to Japanese Patent Application No. 2012-012103 filed on Jan. 24, 2012, the entire contents of this application being incorporated herein by reference in their entirety.
The technical field relates to electronic components, and more particularly, to an electronic component that includes a multilayer body having a coil built in the multilayer body.
As an example of a known electronic component, Japanese Unexamined Patent Application Publication No. 2010-165975 (hereinafter referred to as “Patent Document 1”) describes a multilayer inductor.
The multilayer body 500 of the multilayer inductor described in Patent Document 1 includes a plurality of insulator layers 502 having a rectangular shape that are stacked on top of one another. Outer electrode patterns 506 having an L-shape are provided at corners of the insulator layers 502. The plurality of outer electrode patterns 506 are superposed with one another so as to form outer electrodes. Coil conductor patterns 504 having a partially cut-away ring shape are formed on the respective insulator layers 502. The coil conductor patterns 504 are shaped so as to follow the shapes of the outer electrode patterns 506 in such a manner as to avoid making contact with the outer electrode patterns 506. The plurality of coil conductor patterns 504 are connected together through via hole conductors 505 so as to form a coil.
The present disclosure provides an electronic component capable of having a large inner diameter of a coil.
An electronic component according to an embodiment of the present disclosure includes a multilayer body and a coil that is a helical coil provided in the multilayer body and that includes a plurality of coil conductor layers that are superposed with one another so as to form a ring-shaped path when seen in plan view from a stacking direction and a plurality of via hole conductors that connect the plurality of coil conductor layers together. The ring-shaped path includes a plurality of first corners that project outward of the ring-shaped path and a plurality of second corners that project inward of the ring-shaped path. All of the via hole conductors are provided at the respective first corners.
The inventors realized that the multilayer inductor described in Patent Document 1 has a problem that an inner diameter of the coil is small due to the presence of the via hole conductors 505. It is preferable that the via hole conductors 505 be made as large as possible in view of reducing direct-current resistance of the coil and in view of improving connectivity between each via hole conductor 505 and the corresponding coil conductor patterns 504. However, if each of the via hole conductors 505 is made large, portions of the corresponding coil conductor patterns 504 to which the via hole conductor 505 is connected also needs to be made large in order to prevent deterioration of the connectivity due to misregistration or the like. Here, in the multilayer inductor described in Patent Document 1, each of the via hole conductors 505 is connected to linear portions of the corresponding coil conductor patterns 504. Therefore, if the widths of the portions of the coil conductor patterns 504 to which the via hole conductor 505 are connected is made large, the portions will project into an inner side of the coil. As a result, the inner diameter of the coil will become small.
An electronic component that can address the above shortcomings will now be described.
An electronic component according to an exemplary embodiment will now be described with reference to the accompanying drawings.
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The coil L includes coil conductor layers 18a to 18f, which are sometimes collectively referred to herein as coil conductors 18, and via hole conductors v1 to v6. When seen in plan view from the positive side of the y-axis direction, the coil L has a helical shape that winds clockwise from the negative side of the y-axis direction to the positive side of the y-axis direction. The coil conductor layers 18a to 18f are provided on the insulator layers 16d to 16i, respectively, and when seen in plan view from the y-axis direction, the coil conductor layers 18a to 18f are superposed with one another so as to form a ring-shaped path R. Details of the path R will be described later. Each of the coil conductor layers 18a to 18f has a shape of the path R which is partially cut-away. The coil conductor layers 18 are made of a conductive material, for example, a conductive material mainly composed of Ag. Ends on upstream sides and ends on downstream sides of the coil conductor layers 18 in a clockwise direction are hereinafter referred to as upstream ends and downstream ends, respectively.
Each of the via hole conductors v1 to v6 extends through one of the insulator layers 16e to 16i in the y-axis direction. The via hole conductors v1 to v6 are made of, for example, a conductive material mainly composed of Ag. When seen in plan view from the y-axis direction, the via hole conductors v1 to v6 are provided at different positions on the ring-shaped path R and divide the ring-shaped path R into six sections.
The via hole conductor v1 connects a downstream end of the coil conductor layer 18a with an upstream end of the coil conductor layer 18b. The via hole conductor v2 connects a downstream end of the coil conductor layer 18b with an upstream end of the coil conductor layer 18c. The via hole conductor v3 connects a downstream end of the coil conductor layer 18c with the coil conductor layer 18d. The via hole conductor v4 connects the coil conductor layer 18c with an upstream end of the coil conductor layer 18d. The via hole conductor v5 connects a downstream end of the coil conductor layer 18d with an upstream end of the coil conductor layer 18e. The via hole conductor v6 connects a downstream end of the coil conductor layer 18e with an upstream end of the coil conductor layer 18f.
The via hole conductors v1 to v6 are connected to the coil conductor layers 18a to 18f as described above, so that the coil conductor layers 18a and 18f each have a length of four sections, and the coil conductor layers 18b to 18e each have a length of five sections.
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Portions of the outer electrodes 14a and 14b that are exposed on the outside of the multilayer body 12 can be tin-plated and nickel-plated in order to obtain a good solder connection when being mounted. The insulator layers 16a to 16c are stacked on one side of the outer electrodes 14a and 14b, and the insulator layers 16j to 16l are stacked on the other side of the outer electrodes 14a and 14b in the y-axis direction. Therefore, the outer electrodes 14a and 14b are not exposed on the side surfaces S5 and S6.
The electronic component 10 has a configuration capable of having a large inner diameter of the coil L. The configuration will be described below.
As shown in
Since the straight lines L1 to L8 are structured as described above, the path R includes corners C1, C2, C4, C5, C7, and C8 that project outward of the path R and corners C3 and C6 that project inward of the path R. More specifically, the straight lines L1 and L2 are connected to each other, so that the corner C1 that projects toward the outside of the path R is formed. The straight lines L2 and L3 are connected to each other, so that the corner C2 that projects toward the outside of the path R is formed. The straight lines L3 and L4 are connected to each other, so that the corner C3 that projects toward the inside of the path R is formed. The straight lines L4 and L5 are connected to each other, so that the corner C4 that projects toward the outside of the path R is formed. The straight lines L5 and L6 are connected to each other, so that the corner C5 that projects toward the outside of the path R is formed. The straight lines L6 and L7 are connected to each other, so that the corner C6 that projects toward the inside of the path R is formed. The straight lines L7 and L8 are connected to each other, so that the corner C7 that projects toward the outside of the path R is formed. The straight lines L8 and L9 are connected to each other, so that the corner C8 that projects toward the outside of the path R is formed. As described above, the corners C3 and C6, which project toward the inside of the path R, are provided at corners of the path R that correspond to the corners of the insulator layers 16 at which the external conductive layers 25 and 35 are provided.
The path R having the above configuration avoids the external conductive layers 25 and 35 at the corners C3 and C6. That is, a portion of the path R that faces the external conductive layers 25 and a portion of the path R that faces the external conductive layers 35 have a shape that follows the shape of the external conductive layers 25 and a shape that follows the shape of the external conductive layers 35, respectively. As a result, the path R comes near the external conductive layers 25 and 35 without coming into contact with the external conductive layers 25 and 35. Therefore, an inner diameter of the path R becomes large, and the inner diameter of the coil L becomes large.
Furthermore, each of the via hole conductors v1 to v6 is provided at one of the corners C1, C2, C4, C5, C7, and C8, which project outward, and are not provided at the corners C3 and C6, which project inward. The via hole conductors v1 to v6 are not provided on the straight lines L1 to L8, either. More specifically, the via hole conductor v1 is provided at the corner C4. The via hole conductor v2 is provided at the corner C2. The via hole conductor v3 is provided at the corner C1. The via hole conductor v4 is provided at the corner C8. The via hole conductor v5 is provided at the corner C7. The via hole conductor v6 is provided at the corner C5. Each of the via hole conductors v1 to v6 is provided at one of the corners C1, C2, C4, C5, C7, and C8, which project outward, in this way, and thus, as will be described later, the inner diameter of the path R becomes large, and the inner diameter of the coil L becomes large.
More specifically, it is preferable that the via hole conductors v1 to v6 be made large in view of reducing direct-current resistance of the coil L and in view of improving connectivity between the via hole conductors v1 to v6 and the coil conductor layers 18. If the via hole conductors v1 to v6 are made large as described above, the widths of portions of the coil conductor layers 18 to which the via hole conductors v1 to v6 are connected will be larger than those of the other portions of the coil conductor layers 18.
Here, if any one of the via hole conductors v1 to v6 is provided on one of the straight lines L1 to L8, the widths of a certain portion of the straight lines L1 to L8 will be larger than those of the other portions of the straight lines L1 to L8. As a result, the inner diameter of the path R will become small, and the inner diameter of the coil L will become small.
If each of the via hole conductors v1 to v6 is provided at one of the corners C3 and C6, which project inward, the inner diameter of the path R also will become small as will be described below. More specifically, the corners C3 and C6 are corners that are provided so as to allow the path R to avoid the external conductive layers 25 and 35. The corners C3 and C6 are thus in the vicinity of the external conductive layers 35 and 25, respectively. Therefore, it is difficult to make the widths of the corners C3 and C6 large by making the corners C3 and C6 project toward the outside of the path R in order to provide the via hole conductors v1 to v6 at the corners C3 and C6. Therefore, the widths of the corners C3 and C6 need to be made large by projecting toward the inside of the path R. However, in this case, the inner diameter of the path R becomes small, and the inner diameter of the coil L becomes small.
In the electronic component 10, each of the via hole conductors v1 to v6 is provided at one of the corners C1, C2, C4, C5, C7, and C8, which project outward. The widths of the corners C1, C2, C4, C5, C7, and C8 can thus be made large by making the corners C1, C2, C4, C5, C7, and C8 project toward the outside of the path R. As a result, in the electronic component 10, the inner diameter of the path R becomes large, and the inner diameter of the coil L becomes large.
As will be described below, the electronic component 10 has a configuration in which the electronic component 10 can be mounted in the state shown in
In order to have the above configuration, in the coil L, the coil conductor layer 18a that is a first layer and the coil conductor layer 18f that is a sixth layer are arranged so as to be line-symmetrical to each other with respect to a straight line A2 that passes an intersection point of diagonal lines of each insulator layer 16 and that is perpendicular to the bottom surface S2. The coil conductor layer 18b that is a second layer and the coil conductor layer 18e that is a fifth layer are arranged so as to be line-symmetrical to each other with respect to the straight line A2. The coil conductor layer 18c that is a third layer and the coil conductor layer 18d that is a fourth layer are arranged so as to be line-symmetrical to each other with respect to the straight line A2. Furthermore, the via hole conductor v3 and the via hole conductor v4 are arranged so as to be line-symmetrical to each other with respect to the straight line A2.
The above-described configuration of the coil L may be generalized as follows. The coil L includes n coil conductor layers 18, where n is a natural number of two or more. One of the coil conductor layers 18 that is a kth layer, where k is an integer of zero or more and n or less, and one of the coil conductor layers 18 that is an n−k+1th layer are arranged so as to be line-symmetrical to each other with respect to the straight line A2.
In the electronic component 10 having the above configuration, the coil L has the same configuration in the state shown in
In the electronic component 10, as will be described below, the number of turns of the coil L can be increased. More specifically, the via hole conductors v1 to v6 are provided at six positions on the path R, and the path R is divided into six sections. The coil conductor layers 18 b to 18e each have a length of five sections. Therefore, the lengths of the coil conductor layers 18b to 18e each can be maximized. As a result, in the electronic component 10, the number of turns of the coil L will be increased. Note that in the case where the ring-shaped path R is divided into m sections by the via hole conductors, where m is a natural number of two or more, the coil conductor layers 18 may have a length of m−1 sections.
An exemplary method of manufacturing the electronic component 10 according to the present embodiment will now be described with reference to the accompanying drawings.
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Following this, insulating paste layers 116f to 116i, the coil conductor layers 18c to 18f, the external conductive layers 25c to 25f and 35c to 35f, and the via hole conductors v2 to v6 are formed by repeating the process shown in
Next, as shown in
Next, the mother multilayer body 112 is cut into a plurality of green multilayer bodies 12 by dicing or the like. In a cutting process of the mother multilayer body 112, the outer electrodes 14a and 14b will be exposed from the green multilayer bodies 12, on the corresponding cut surfaces that are formed by cutting.
Next, the green multilayer bodies 12 are baked under predetermined conditions so as to obtain the multilayer bodies 12. Furthermore, barrel polishing can be performed on the multilayer bodies 12.
Finally, portions of the outer electrodes 14a and 14b that are exposed from the multilayer bodies 12 can be plated, for example, tin-plated with a thickness in the range of 2 μm to 7 μm and nickel-plated with a thickness in the range of 2 μm to 7 μm. The electronic component 10 is completed through the above processes.
An electronic component 10a according to an exemplary modification will now be described with reference to the accompanying drawing.
A difference between the electronic component 10 and the electronic component 10a is the number of the coil conductor layers 18. More specifically, six coil conductor layers 18 (i.e., an even number of conductor layers) are provided in the electronic component 10, whereas five coil conductor layers 18 (i.e., an odd number of conductor layers) are provided in the electronic component 10a. The difference will be described in further detail below.
In the electronic component 10a, a coil conductor layer 18a that is a first layer and a coil conductor layer 18e that is a fifth layer are arranged so as to be line-symmetrical to each other with respect to a straight line A2. A coil conductor layer 18b that is a second layer and a coil conductor layer 18d that is a fourth layer are arranged so as to be line-symmetrical to each other with respect to the straight line A2.
Since the number of the coil conductor layers 18 is an odd number, there is no coil conductor layer 18 that corresponds to a coil conductor layer 18c. However, one of the coil conductor layers 18 that is a kth layer and one of the coil conductor layers 18 that is an n−k+1th layer are arranged so as to be line-symmetrical to each other with respect to the straight line A2. In the case where k=3 and n=5, the coil conductor layer 18c that is a third layer and the coil conductor layer 18c that is the third layer are arranged so as to be line-symmetrical to each other with respect to a straight line A2. That is, the coil conductor layer 18c has a line-symmetrical configuration with respect to a straight line A2.
As with the electronic component 10, the electronic component 10a having the above configuration is capable of having a large inner diameter of the coil L. In addition, as with the electronic component 10, the electronic component 10a can be mounted in the state shown in
An electronic component according to the present disclosure is not limited to the electronic components 10 and 10a according to the above-described embodiment, and modifications can be made within the scope of the present disclosure.
Although six coil conductor layers 18 are provided in the electronic component 10, and five coil conductor layers 18 are provided in the electronic component 10a, the number of the coil conductor layers 18 of the electronic component 10 and 10a are not limited thereto.
Although the insulating paste layers 116 are formed through a photolithography process in the electronic components 10 and 10a, the insulating paste layers 116 may be formed by screen printing.
The path R may not avoid the outer electrodes 14a and 14b but may avoid via hole conductors or other conductive layers at the corners C3 and C6.
Number | Date | Country | Kind |
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2012-012103 | Jan 2012 | JP | national |