WO2010087220A1

WO2010087220A1 - Electronic component and method of manufacturing same

Info

Publication number: WO2010087220A1
Application number: PCT/JP2010/050143
Authority: WO
Inventors: 智之前田
Original assignee: 株式会社村田製作所
Priority date: 2009-01-30
Filing date: 2010-01-08
Publication date: 2010-08-05
Also published as: JP5703754B2; CN102301436A; JPWO2010087220A1; CN102301436B; KR101266307B1; KR20110089201A

Abstract

A multilayer electronic component wherein disconnection between a via hole conductor and coil electrodes can be prevented; and a method of manufacturing the same. The via hole conductor (B) is connected to a plurality of coil electrodes (18) and has a shape in which the area of one end part (t1) is larger than the area of the other end part (t2). A coil electrode (18a) is defined as a start electrode, a coil conductor (20) is defined as an end electrode, and coil electrodes (18b to 18e) other than the start electrode and end electrode are defined as intermediate electrodes. The start electrode is connected to the via hole conductor (B4), which is connected to the intermediate electrodes, by the larger end part (t1) of the same.

Description

Electronic component and manufacturing method thereof

The present invention relates to an electronic component and a manufacturing method thereof, and relates to an electronic component in which an insulating layer and a coil electrode are laminated and a manufacturing method thereof.

Hereinafter, the structure of a conventional electronic component incorporating a coil will be described with reference to the drawings. FIG. 10 is a perspective view of a conventional electronic component 200. FIG. 11 is an exploded perspective view of a multilayer body 202 of a conventional electronic component 200.

As shown in FIG. 10, the electronic component 200 includes a rectangular parallelepiped laminated body 202 including a coil inside, and two external electrodes 212 a and 212 b formed on opposite side surfaces of the laminated body 202.

The laminate 202 is configured by laminating a plurality of coil electrodes and a plurality of magnetic layers. Specifically, it is as follows. As shown in FIG. 11, the multilayer body 202 includes a plurality of magnetic layers 204a to 204f, 206a to 206d made of ferromagnetic ferrite (for example, Ni—Zn—Cu ferrite or Ni—Zn ferrite). It is constituted by. Coil electrodes 208a to 208f constituting coils are formed on the magnetic layers 204a to 204f. In addition, via hole conductors B51 to B55 are formed in the magnetic layers 204a to 204e. The via hole conductors B51 to B55 are formed, for example, by forming a via hole by irradiating a laser and filling the via hole with a conductor. Therefore, as shown in FIG. 10, the via-hole conductors B51 to B55 have a shape in which the area of one end is relatively large and the area of the other end is relatively small.

The coil electrodes 208a to 208f are electrodes having a “U” shape and a length of 3/4 turns. The via-hole conductors B1 to B5 are provided so as to penetrate the magnetic layers 204a to 204e in the vertical direction at one end of each of the coil electrodes 208a to 208e. The coil electrodes 208a to 208f are connected to each other by via hole conductors B51 to B55, thereby forming a spiral coil. Furthermore, extraction electrodes 210a and 210b are provided on the coil electrodes 208a and 208f formed on the uppermost and lowermost sides in the stacking direction, respectively. The lead electrodes 210a and 210b serve to connect the coil and the external electrodes 212a and 212b.

As described below, the conventional electronic component 200 configured as described above has a problem in that disconnection is likely to occur between the coil electrode 208f and the via-hole conductor B55.

As shown in FIG. 11, the length of the coil electrode 208f is longer than the length of the coil electrode 208a. Therefore, when a current is passed through the coil, the amount of heat generated in the coil electrode 208f is greater than the amount of heat generated in the coil electrode 208a. Further, the end portion of the via hole conductor B55 having the smaller area is connected to the coil electrode 208f. Therefore, heat is intensively generated particularly at the connection portion between the coil electrode 208f and the via-hole conductor B55. As a result, disconnection is likely to occur between the coil electrode 208f and the via-hole conductor B55.

Note that Patent Document 1 describes a multilayer electronic component in which the uppermost coil conductor and the lowermost coil conductor have the same shape. However, Patent Document 1 does not mention the problem of disconnection at the connection portion between the via conductor and the coil conductor.

JP 2005-167130 A

Therefore, an object of the present invention is to provide an electronic component that can prevent disconnection between a via-hole conductor and a coil electrode, and a manufacturing method thereof.

An electronic component according to an aspect of the present invention is
A plurality of coil electrodes constituting a coil;
A plurality of insulating layers laminated together with the plurality of coil electrodes to form a laminate;
Two external electrodes provided on the surface of the laminate, two connection portions for connecting the coil and the two external electrodes,
A via-hole conductor connecting the plurality of coil electrodes and having a shape in which the area of one end is larger than the area of the other end;
With
Of the coil electrodes provided at both ends in the stacking direction, the coil electrode having a relatively large DC resistance value between the connected via-hole conductor and the connecting portion is defined as a start electrode and connected. The coil electrode having a relatively small direct current resistance value between the via-hole conductor and the connecting portion is defined as an end electrode, and the coil electrode other than the start electrode and the end electrode is defined as an intermediate electrode. sometimes,
The start electrode is connected to the via-hole conductor connected to the intermediate electrode via the one end;
It is characterized by.

In the electronic component, the end electrode has a length equal to or greater than the number of turns obtained by subtracting the number of turns of the intermediate electrode from one turn, and the via-hole conductor connected to the intermediate electrode; It may be connected via the other end.

In the electronic component, the via-hole conductor that connects the end electrode and the intermediate electrode may be integrally formed with the end electrode in the insulating layer.

In the electronic component, the end electrode may overlap the via-hole conductor connected to the intermediate electrode when viewed in plan from the stacking direction.

In the electronic component, the via-hole conductor that connects the start electrode and the intermediate electrode may be formed integrally with the start electrode in the insulating layer.

In the electronic component, when the direction from the end electrode toward the start electrode is defined as a first direction, in each via-hole conductor, the one end portion is more first than the other end portion. It may be located on the direction side.

In the electronic component, the end electrode may be configured to be connectable to the via-hole conductor at a plurality of locations.

In the electronic component, the end electrode may have a shape in which a portion connectable to the via-hole conductor is thicker than other portions.

In the electronic component, a via-hole conductor connecting the end electrode and the intermediate electrode may be connected to a portion other than both ends of the end electrode.

In the electronic component, the connection portion may be a via hole conductor.

In the electronic component, the connection portion may be a lead electrode provided on the insulating layer and connected to the start electrode or the end electrode.

The method for manufacturing the electronic component includes:
Forming the via-hole conductor in the insulating layer;
Forming the connecting portion in the insulating layer;
Forming the start electrode and the intermediate electrode on the insulating layer;
Forming the end electrode on the insulating layer;
The insulating layer in which the start electrode is formed, the insulating layer in which the end electrode is formed, and the intermediate electrode are formed so that the intermediate electrode is positioned between the start electrode and the end electrode Laminating insulating layers to form a laminate;
Providing
It is characterized by.

In the electronic component manufacturing method, the step of forming the via-hole conductor and the step of forming the start electrode and the intermediate electrode may be performed simultaneously.

According to the present invention, disconnection between the via-hole conductor and the coil electrode can be prevented.

1 is an external perspective view of an electronic component according to an embodiment of the present invention. It is a disassembled perspective view of the laminated body of the electronic component of FIG. It is a disassembled perspective view of the laminated body of an electronic component when changing the number of turns of a coil. It is the figure which saw through the electronic component of FIG. 1 from the y-axis direction. It is a disassembled perspective view of the laminated body of the conventional electronic component. It is a disassembled perspective view of the laminated body of the conventional electronic component. It is the figure which saw through the conventional electronic component from the y-axis direction. It is the figure which showed the coil electrode produced on the ceramic green sheet in experiment. The figure which showed the modification of the coil electrode. The perspective view of the conventional electronic component. The exploded perspective view of the laminated body of the conventional electronic component.

Hereinafter, an electronic component and a manufacturing method thereof according to an embodiment of the present invention will be described. The electronic component is used in, for example, an inductor, an impeder, an LC filter, and an LC filter array.

(Configuration of electronic parts)
First, the configuration of an electronic component according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of an electronic component 10 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the laminate 12 of the electronic component 10 of FIG. Hereinafter, the stacking direction of the stacked body 12 is defined as the z-axis direction, and the directions orthogonal to the z-axis direction are defined as the x-axis direction and the y-axis direction. The x-axis direction and the y-axis direction are parallel to the sides of the stacked body 12.

The electronic component 10 includes a laminate 12 and

external electrodes

14a and 14b as shown in FIG. The laminated body 12 has a rectangular parallelepiped shape and includes a coil L therein. The

external electrodes

14 a and 14 b are provided on the surfaces positioned at both ends in the z-axis direction of the multilayer body 12, and are connected to the coil L.

The laminate 12 is configured by laminating a plurality of coil electrodes and a plurality of insulating layers together. Specifically, it is as follows. As shown in FIG. 2, the laminate 12 includes a plurality of magnetic layers 16a to 16l made of ferromagnetic ferrite (for example, Ni—Zn—Cu ferrite, Ni—Zn ferrite, etc.) in the positive direction side in the z-axis direction. Are stacked so as to be arranged in this order from the negative direction side to the negative direction side. The plurality of magnetic layers 16a to 16l are insulating layers having substantially the same area and the same rectangular shape. Coil electrodes 18a to 18e and 20 constituting the coil L are provided on the main surfaces of the magnetic layers 16d to 16i, respectively. Further, via hole conductors B1 to B12 are provided in the magnetic layers 16a to 16l, respectively. A dielectric or an insulator may be used instead of the magnetic layers 16a to 16l made of ferrite. In the following, when the individual magnetic layers 16a to 16l and the coil electrodes 18a to 18e are shown, an alphabet is added after the reference symbol, and the magnetic layers 16a to 16l and the coil electrodes 18a to 18e are collectively referred to. Shall omit the alphabet after the reference sign. In addition, when the individual via-hole conductors B1 to B12 are shown, a number is added after B, and when the via-hole conductors B1 to B12 are generically referred to, the number after B is omitted.

The

coil electrodes

18 and 20 are made of a conductive material made of Ag and have a shape in which a part of the ring is cut away. In the present embodiment, the

coil electrodes

18 and 20 are U-shaped. Thereby, each

coil electrode

18 and 20 comprises the electrode which has the length of 3/4 turn. The

coil electrodes

18 and 20 may be made of a conductive material such as a noble metal mainly composed of Pd, Au, Pt or the like, or an alloy thereof. The

coil electrodes

18 and 20 may have a shape in which a part of a circle or an ellipse is cut out. Hereinafter, the configuration of each of the coil electrodes 18a to 18e, 20 will be described.

The coil electrode 18a is provided on the magnetic layer 16d arranged on the most positive side in the z-axis direction among the magnetic layers 16d to 16i, and is called a start electrode. The coil electrode 18a has the same number of turns as the coil electrodes 18b to 18e. A contact portion C1 is provided at one end of the coil electrode 18a, and a contact portion C2 is provided at the other end of the coil electrode 18a. The contact part C1 is electrically connected to the external electrode 14a via the via-hole conductors B1 to B3. Therefore, the contact portion C1 is provided at a position overlapping the via-hole conductors B1 to B3 when viewed in plan from the z-axis direction. Further, the contact portion C1 is formed thicker than other portions of the coil electrode 18a so as to be easily connected to the via-hole conductor B3. The contact portion C2 is formed thicker than other portions of the coil electrode 18a so as to be easily connected to the via-hole conductor B4, and is formed integrally with the via-hole conductor B4.

The coil electrode 18b is provided on the magnetic layer 16e and is called an intermediate electrode. A contact portion C3 is provided at one end of the coil electrode 18b, and a contact portion C4 is provided at the other end of the coil electrode 18b. The contact portion C3 is formed thicker than other portions of the coil electrode 18b so that the contact portion C3 can be easily connected to the via-hole conductor B4 when the magnetic layer 16d and the magnetic layer 16e are laminated. The contact portion C4 is formed thicker than other portions of the coil electrode 18b so as to be easily connected to the via-hole conductor B5, and is formed integrally with the via-hole conductor B5.

The coil electrode 18c is provided on the magnetic layer 16f and is called an intermediate electrode. A contact portion C5 is provided at one end of the coil electrode 18c, and a contact portion C6 is provided at the other end of the coil electrode 18c. The contact portion C5 is formed thicker than other portions of the coil electrode 18c so that the contact portion C5 can be easily connected to the via-hole conductor B5 when the magnetic layer 16e and the magnetic layer 16f are laminated. Further, the contact portion C6 is formed thicker than other portions of the coil electrode 18c so as to be easily connected to the via-hole conductor B6, and is formed integrally with the via-hole conductor B6.

The coil electrode 18d is provided on the magnetic layer 16g and is called an intermediate electrode. A contact portion C7 is provided at one end of the coil electrode 18d, and a contact portion C8 is provided at the other end of the coil electrode 18d. The contact part C7 is formed thicker than the other part of the coil electrode 18d so that it can be easily connected to the via-hole conductor B6 when the magnetic layer 16f and the magnetic layer 16g are laminated. Further, the contact portion C8 is formed thicker than other portions of the coil electrode 18d so as to be easily connected to the via-hole conductor B7, and is formed integrally with the via-hole conductor B7.

The coil electrode 18e is provided on the magnetic layer 16h and is called an intermediate electrode. A contact portion C9 is provided at one end of the coil electrode 18e, and a contact portion C10 is provided at the other end of the coil electrode 18e. The contact portion C9 is formed thicker than the other portions of the coil electrode 18e so that it can be easily connected to the via-hole conductor B7 when the magnetic layer 16g and the magnetic layer 16h are laminated. Further, the contact portion C10 is formed thicker than other portions of the coil electrode 18e so as to be easily connected to the via-hole conductor B8, and is formed integrally with the via-hole conductor B8.

The coil electrode 20 is provided on the magnetic layer 16i disposed on the most negative side in the z-axis direction among the magnetic layers 16d to 16i, and is called an end electrode. The coil electrode 20 has a length equal to or greater than the number of turns obtained by subtracting the number of turns of the coil electrodes 18b to 18e that are intermediate electrodes from one turn (in this embodiment, the number of turns of the coil electrode 20). And the number of turns of the coil electrodes 18b to 18e is equal). A contact portion C11 is provided at one end of the coil electrode 20, and a contact portion C14 is provided at the other end of the coil electrode 20. Furthermore, the coil electrode 20 has contact portions C12 and C13 so that the coil electrode 20 can be connected to the via-hole conductor B at a plurality of locations. More specifically, the coil electrode 18 has a U-shape and can be connected to the via-hole conductor B at its four corners. Therefore, the coil electrode 20 has contact portions C11 to C14 at the four corners so as to be connectable to the via-hole conductors B provided at the four corners.

The contact portion C13 is formed thicker than other portions of the coil electrode 20 so that the magnetic layer 16h and the magnetic layer 16i are easily connected to the via-hole conductor B8 when the magnetic layer 16h and the magnetic layer 16i are laminated. The contact portion C14 is electrically connected to the external electrode 14b via the via-hole conductors B9 to B12. Therefore, the contact portion C14 is provided at a position overlapping the via-hole conductors B9 to B12 when viewed in plan from the z-axis direction. Further, the contact portion C14 is formed thicker than other portions of the coil electrode 20 so as to be easily connected to the via-hole conductor B9, and is formed integrally with the via-hole conductor B9. Further, the contact portions C11 and C12 are formed thicker than other portions of the coil electrode 20 so as to be easily connected to the via-hole conductor B. In the following, when the individual contact portions C1 to C14 are shown, a number is appended to the C, and when the contact portions C1 to C14 are generically referred to, the number after the C is omitted.

As described above, in the electronic component 10, the start electrode (coil electrode 18a) located at the end on the positive direction side in the z-axis direction and the end electrode (coil) located at the end on the negative direction side in the z-axis direction. The coil L is composed of the electrode 20) and four kinds of intermediate electrodes (coil electrodes 18b to 18e) other than the start electrode and the end electrode. When the number of turns of the coil L is adjusted, an appropriate coil electrode among the coil electrodes 18b to 18e serving as intermediate coils is interposed between the coil electrode 20 serving as an end electrode and the coil electrode 18e serving as an intermediate electrode. 18 is inserted. Specifically, it is as follows. FIG. 3 is an exploded perspective view of the multilayer body 12 of the electronic component 10 when the number of turns of the coil L is changed.

For example, when it is desired to increase the number of turns of the coil L of the laminate 12 shown in FIG. 2 by one turn, as shown in FIG. 3, a coil electrode is interposed between the magnetic layer 16h and the magnetic layer 16i. What is necessary is just to insert the magnetic body layer 16m provided with 18f and the via-hole conductor B13. The magnetic layer 16m, the coil electrode 18f, and the via hole conductor B13 have the same structure as the magnetic layer 16e, the coil electrode 18b, and the via hole conductor B5. Thereby, the number of turns of the coil can be changed.

When the magnetic layer 16m is not inserted as shown in FIG. 2, the contact portion C13 is used for connection to the via-hole conductor B8. When the magnetic layer 16m is inserted as shown in FIG. 3, the contact portion C12 is used for connection to the via-hole conductor B13. Thus, the coil electrode 20 overlaps with the via-hole conductor B connected to the coil electrodes 18e and 18f, which are intermediate electrodes, when viewed in plan from the z-axis direction. Both can be connected. Further, the coil electrode 20 has a configuration that can be connected to the coil electrode 18c by overlapping with the via-hole conductor B connected to the coil electrode 18c that is an intermediate electrode when viewed in plan from the z-axis direction. ing.

Next, the via-hole conductor B will be described. FIG. 4 is a perspective view of the electronic component 10 seen from the y-axis direction. As shown in FIG. 2, the via-hole conductor B is provided so as to penetrate the magnetic layer 16 in the z-axis direction. As shown in FIG. 4, when viewed from the y-axis direction, the via-hole conductor B has one end t1. The area is larger than the area of the other end t2. More specifically, the area of the end t1 located on the positive side in the z-axis direction is larger than the area of the end t2 located on the negative side in the z-axis direction. Below, the connection relationship of each via-hole conductor B is demonstrated.

The via-hole conductors B1 to B3 are connected so as to be arranged in a straight line in the z-axis direction. An end t2 of the via-hole conductor B3 is connected to the coil electrode 18a. An end t1 of the via-hole conductor B4 is connected to the coil electrode 18a, and an end t2 of the via-hole conductor B4 is connected to the coil electrode 18b. An end t1 of the via-hole conductor B5 is connected to the coil electrode 18b, and an end t2 of the via-hole conductor B5 is connected to the coil electrode 18c. An end t1 of the via-hole conductor B6 is connected to the coil electrode 18c, and an end t2 of the via-hole conductor B6 is connected to the coil electrode 18d. An end t1 of the via-hole conductor B7 is connected to the coil electrode 18d, and an end t2 of the via-hole conductor B7 is connected to the coil electrode 18e. An end t1 of the via-hole conductor B8 is connected to the coil electrode 18e, and an end t2 of the via-hole conductor B8 is connected to the coil electrode 20. The via-hole conductors B9 to B12 are connected so as to be arranged in a straight line in the z-axis direction. An end t1 of the via-hole conductor B9 is connected to the coil electrode 20. As a result, in all the via-hole conductors B1 to B12, the end t1 is positioned closer to the positive side in the z-axis direction than the end t2.

In the electronic component 10 having the above-described configuration, the coil electrode 20 is different for each of the via-hole conductors B8 and B13 connected to the coil electrodes 18e and 18f, which are intermediate electrodes, as shown in FIGS. They are connected via contact parts C12 and C13. Therefore, when the number of turns of the coil L changes, the distance between the two via-hole conductors B connected to the coil electrode 20 also changes. More specifically, in the state shown in FIG. 2, the distance between the two via-hole conductors B8 and B9 connected to the coil electrode 20 is relatively short, and in the state shown in FIG. The distance between the two via-hole conductors B9 and B13 is relatively long. Since both the coil electrode 18a and the coil electrode 20 have a length of 3/4 turns, the DC resistance value between the two via-hole conductors B connected to the coil electrode 20 that is an end electrode is The DC resistance value between the two via-hole conductors B connected to the coil electrode 18a as the start electrode is relatively large.

(Method for manufacturing electronic parts)
Hereinafter, a method for manufacturing the electronic component 10 will be described with reference to FIGS. 1 and 2. In the manufacturing method described below, one electronic component 10 is manufactured by a sheet lamination method. However, in the manufacturing method, a mother laminate may be produced using a large ceramic green sheet and cut into individual laminates 12.

First, a ceramic green sheet to be the magnetic layer 16 is produced as follows. Ratio of ferric oxide (Fe ₂ O ₃ ) 48.0 mol%, zinc oxide (ZnO) 25.0 mol%, nickel oxide (NiO) 18.0 mol%, copper oxide (CuO) 9.0 mol% Each material weighed in step 1 is put into a ball mill as a raw material and wet blended. The obtained mixture is dried and pulverized, and the obtained powder is calcined at 750 ° C. for 1 hour. The obtained calcined powder is wet pulverized by a ball mill, dried and then crushed to obtain a ferrite ceramic powder.

To this ferrite ceramic powder, a binder (vinyl acetate, water-soluble acrylic, etc.), a plasticizer, a wetting material, and a dispersing agent are added and mixed with a ball mill, and then defoamed under reduced pressure. The obtained ceramic slurry is formed into a sheet by a doctor blade method and dried to produce a ceramic green sheet having a desired film thickness (for example, 35 μm).

A via-hole conductor B is formed on the ceramic green sheet to be the magnetic layer 16. Specifically, a through hole is formed in a ceramic green sheet using a laser beam. Here, the laser beam passes through the ceramic green sheet while being attenuated. Therefore, the through hole has a tapered shape in which the area of the opening on the side irradiated with the laser beam is large and the area of the opening on the opposite side is small. Next, the through holes are filled with a conductive paste such as Ag, Pd, Cu, Au, or an alloy thereof by a method such as printing. As a result, as shown in FIG. 4, a via-hole conductor B having a shape in which the area of one end t1 is larger than the area of the other end t2 when viewed from the y-axis direction is formed.

Next, a conductive paste mainly composed of Ag, Pd, Cu, Au, or an alloy thereof is applied on the ceramic green sheets to be the magnetic layers 16d to 16h by a method such as a screen printing method or a photolithography method. By applying, coil electrodes 18a to 18e which are start electrodes and intermediate electrodes are formed. Specifically, in the ceramic green sheets to be the magnetic layers 16d to 16h, the coil electrode 18 is formed on the main surface on the end t1 side of the via-hole conductor B so that the contact portion C and the via-hole conductor B overlap each other. . The coil electrode 18 and the via-hole conductor B may be simultaneously formed on the ceramic green sheet.

Next, a conductive paste mainly composed of Ag, Pd, Cu, Au, or an alloy thereof is applied on the ceramic green sheet to be the magnetic layer 16i by a method such as a screen printing method or a photolithography method. Thereby, the coil electrode 20 which is an end electrode is formed. Specifically, in the ceramic green sheet to be the magnetic layer 16i, the coil electrode 20 is formed on the main surface on the end t1 side of the via-hole conductor B9 so that the contact portion C14 and the via-hole conductor B9 overlap. Note that the coil electrode 20 and the via-hole conductor B9 may be simultaneously formed on the ceramic green sheet.

Next, the ceramic green sheets are laminated to form an unfired laminate 12. At this time, the coil electrodes 18b to 18e (intermediate electrodes) are located between the coil electrode 18a (start electrode) and the coil electrode 20 (end electrode), and the coil electrode 20 is connected to the coil electrode 18e. The direct-current resistance value between the via-hole conductors B3 and B4 connected to the conductor B8 via the end t2 and connected to the coil electrode 18a is equal to the direct-current resistance between the via-hole conductors B8 and B9 connected to the coil electrode 20 The stacked body 12 is formed so as to be larger than the value. Specifically, a ceramic green sheet to be the magnetic layer 16l is disposed. Next, the ceramic green sheet to be the magnetic layer 16k is disposed and temporarily pressed onto the ceramic green sheet to be the magnetic layer 16l. Thereafter, the ceramic green sheets to be the

magnetic layers

16j, 16i, 16h, 16g, 16f, 16e, 16d, 16c, 16b, and 16a are also temporarily bonded by the same procedure. Thereby, the unfired laminated body 12 is formed. The green laminate 12 is subjected to main pressure bonding by an isostatic press or the like.

Next, the laminate 12 is subjected to binder removal processing and firing. The firing temperature is 900 ° C., for example. Thereby, the baked laminated body 12 is obtained. On the surface of the laminate 12, for example, an electrode paste whose main component is silver is applied and baked by a method such as an immersion method, thereby forming silver electrodes to be the

external electrodes

14 a and 14 b.

Finally, Ni plating / Sn plating is performed on the surface of the silver electrode to be the

external electrodes

14a and 14b. Through the above steps, the electronic component 10 as shown in FIG. 1 is completed.

(effect)
According to the electronic component 10, disconnection between the via-hole conductor B4 and the coil electrode 18a can be prevented. Specifically, in the electronic component 10, the coil electrode 18 a is formed longer than the coil electrode 20, so that when current is passed through the coil L, heat is generated more strongly than the coil electrode 20. In particular, heat is intensively generated at the connection portion between the coil electrode 18a and the via-hole conductor B4.

Therefore, in the electronic component 10, as shown in FIG. 4, the end t1 of the via-hole conductor B4 is connected to the coil electrode 18a. The end t1 has a larger area than the end t2. Therefore, in the electronic component 10, the DC resistance value at the connection portion between the coil electrode 18a and the via-hole conductor B4 is reduced, and the connection portion is prevented from generating heat intensively. As a result, occurrence of disconnection at the boundary portion between the coil electrode 18a and the via-hole electrode B4 is suppressed.

The inventor of the present application conducted the electrostatic discharge test shown below to evaluate the disconnection occurrence rate in order to make the effect clearer. For the test, the first prototype and the second prototype were used. The first prototype corresponds to the electronic component 10 according to the present embodiment. Specifically, the electronic component 10 shown in FIGS. 2 and 3 was used. The second prototype used the electronic component 10 shown in FIGS. 2 and 3 with the via hole conductor B reversed in the z-axis direction. The details of the first prototype and the second prototype are as follows.

Size: 1.00mm x 0.50mm x 0.50mm
Material of magnetic layer: Ni—Cu—Zn ferrite external electrode material: Ni—Sn plated coil electrode material on silver electrode: Silver coil electrode length: 3/4 turn Coil turn number: 10 turns manufacture Method: Sheet lamination method

A large number of first prototypes and second prototypes are produced, each of which satisfies the condition of Rdc ≧ average + 3σ (where the average is the average value of a large number of Rdcs) Extraction was performed, and a voltage of 30 kV was applied to the 100 first prototypes and the second prototypes 30 times each in the positive and negative directions at 0.1 second intervals. The results obtained are shown in Table 1.

As described above, in the second prototype, a disconnection occurred in some of the products, but in the first prototype, no disconnection occurred. Therefore, it can be understood that the electronic component 10 according to the present embodiment can suppress the occurrence of disconnection.

Further, in the electronic component 10, the via-hole conductor B4 that connects the coil electrode 18a that is the start electrode and the coil electrode 18b that is the intermediate electrode is formed integrally by being formed simultaneously with the coil electrode 18a in the manufacturing process. ing. For this reason, the connection between the coil electrode 18a and the via-hole conductor B4 is strengthened, and disconnection is less likely to occur at the connection portion between the coil electrode 18a and the via-hole conductor B4.

Moreover, according to the electronic component 10 and the manufacturing method thereof, as described below, the number of turns of the coil L can be changed without redesigning the position of the via-hole conductor B. 5 and 6 are exploded perspective views of the multilayer body 112 of the conventional electronic component 110. FIG. FIG. 7 is a perspective view of the electronic component 110 seen from the y-axis direction. Hereinafter, the stacking direction of the stacked body 112 is defined as the z-axis direction, and the directions orthogonal to the z-axis direction are defined as the x-axis direction and the y-axis direction. The x-axis direction and the y-axis direction are parallel to the sides of the stacked body 112.

As shown in FIG. 1, the electronic component 110 includes a rectangular parallelepiped laminated body 112 including a coil therein, and two external electrodes 114 a provided on the surfaces of the laminated body 112 positioned at both ends in the z-axis direction. 114b.

The laminated body 112 is configured by laminating a plurality of coil electrodes and a plurality of magnetic layers. Specifically, it is as follows. As shown in FIG. 5, the multilayer body 112 includes a plurality of magnetic layers 116a to 116l made of ferromagnetic ferrite (for example, Ni—Zn—Cu ferrite, Ni—Zn ferrite, etc.) in the negative direction side in the z-axis direction. Are stacked so as to be arranged in this order from the positive side to the positive direction side. The magnetic layers 116d to 116i are provided with coil electrodes 118a to 118e, 120 constituting a coil. In addition, via hole conductors b1 to b12 are provided in the magnetic layers 116a to 116l.

The coil electrodes 118a to 118e, 120 are U-shaped, and are linear electrodes having a length of 3/4 turns. The via-hole conductors b5 to b8 are provided so as to penetrate the magnetic layers 116e to 116h in the z-axis direction at one ends of the coil electrodes 118b to 118e, respectively. Further, the via-hole conductor b9 is provided so as to penetrate the magnetic layer 116i in the z-axis direction at the corner portion located at the lower left of the coil electrode 120. As a result, the coil electrodes 118a to 118e and 120 are connected to each other by the via-hole conductors b5 to b9, thereby forming a spiral coil.

Further, the via-hole conductors b1 to b4 are provided so as to penetrate the magnetic layers 116a to 116d in the z-axis direction, respectively, and electrically connect the coil electrode 118a and the external electrode 114a. The via-hole conductors b10 to b12 are provided so as to penetrate the magnetic layers 116j to 116l in the z-axis direction, respectively, and electrically connect the coil electrode 120 and the external electrode 114b.

In the conventional electronic component 110 configured as described above, the number of turns of the coil can be changed as described below. FIG. 6 is an exploded perspective view of the laminate 112 when the number of turns of the coil is changed.

When it is desired to increase the number of turns of the coil of the laminated body 112 shown in FIG. 5 by one turn, as shown in FIG. 6, between the magnetic layer 116h and the magnetic layer 116i, a coil electrode 118f and a via hole are provided. The magnetic layer 116m provided with the conductor b13 may be inserted. The coil electrode 118f and the via hole conductor b13 have the same structure as the coil electrode 118b and the via hole conductor b5. Thereby, the number of turns of the coil can be changed. In the case where it is desired to further increase the number of turns of the coil of the laminated body 112 by one turn from the state of FIG. 6, the same structure as that of the magnetic layer 116f is provided between the magnetic layer 116m and the magnetic layer 116i. It is sufficient to insert a magnetic layer 116 having

However, in the electronic component 110, as shown in FIGS. 5 and 6, when the number of turns of the coil is changed, the position of the end of the coil electrode 118 located on the negative side of the z-axis direction of the coil electrode 120 changes. To do. Therefore, in order to connect the coil electrode 118 and the coil electrode 120 located on the negative side of the z-axis direction of the coil electrode 120, the position of the via-hole conductor b9 must be changed. That is, in the electronic component 110, it is necessary to redesign the position of the via-hole conductor b9 when changing the number of turns of the coil.

On the other hand, in the electronic component 10 shown in FIG. 2, the coil electrode 20 as an end electrode is provided on the lowermost side in the stacking direction. The coil electrode 18 provided immediately above the coil electrode 20 changes depending on the number of turns of the coil L. Therefore, when the number of turns of the coil L changes, the position of the end of the coil electrode 18 changes.

However, the coil electrode 18 and the coil electrode 20 are connected by a via-hole conductor B formed integrally with the coil electrode 18. Therefore, when the number of turns of the coil L changes and the position of the end of the coil electrode 18 changes, the position of the via-hole conductor B also changes together with the position of the end of the coil electrode 18. However, the coil electrode 18 provided immediately above the coil electrode 20 has the same structure as the coil electrodes 18b to 18e. Therefore, in the electronic component 10, even if the position of the end portion of the coil electrode 18 and the position of the via-hole conductor B are changed, it is not necessary to redesign the position of the via-hole conductor B. The via hole conductor B being integrally formed with the coil electrode 18 refers to a state in which the via hole conductor B8 and the coil electrode 18e are simultaneously formed in the manufacturing process.

Furthermore, in the electronic component 10, the coil electrode 20 that is an end electrode overlaps with the via-hole conductor B that is connected to the coil electrodes 18b to 18e that are intermediate electrodes when viewed in plan from the z-axis direction. Therefore, even if the position of the via-hole conductor B connected to the coil electrode 20 changes by changing the number of turns of the coil L, the coil electrode 20 and the via-hole conductor B are connected to any one of the contact portions C11 to C14. Can be connected. As a result, in the electronic component 10, it is not necessary to redesign the coil electrode 20 when changing the number of turns of the coil L. That is, in the electronic component 10, it is sufficient to prepare only one type of coil electrode 20 that is an end electrode.

However, as shown in FIG. 2, the coil electrode 20 is not necessarily required to have a length (3/4 turn) that overlaps the via-hole conductor B connected to the coil electrodes 18b to 18e. The coil electrode 20 only needs to have at least a length equal to or greater than the number of turns obtained by subtracting the number of turns of the coil electrodes 18a to 18e that are intermediate electrodes from one turn. Thereby, the coil electrode 20 can be connected to the via-hole conductor B at at least two places. More specifically, when the coil electrode 20 has a length of 1/4 turn, the coil electrode 20 can be connected to the via-hole conductors B8 and B9 as shown in FIG. When the coil electrode 20 has a length of 1/2 turn, the coil electrode 20 can be connected to the via-hole conductors B9 and B13 as shown in FIG. However, in this case, if the length of the coil L is changed, the coil electrode 20 needs to be redesigned.

Moreover, according to the electronic component 10 according to the present embodiment, it is possible to suppress the occurrence of poor formation of the via-hole conductor B9 connected to the coil electrode 20 as described below. More specifically, in the conventional electronic component 110 shown in FIGS. 5 and 6, a via-hole conductor b <b> 9 is provided in the middle of the coil electrode 120.

However, in the coil conductor 120 in which the via-hole conductor b9 is formed in the middle of the coil electrode 120 as shown in FIGS. 5 and 6, there is a possibility that a formation defect of the via-hole conductor b9 occurs. Specifically, in the coil conductor 120 shown in FIGS. 5 and 6, since the via-hole conductor b9 is formed in the middle of the coil electrode 120, the wiring of the coil electrode 120 extends in two directions from the via-hole conductor b9. Therefore, when the coil conductor 120 is formed by the screen printing method, the conductive paste is used for forming the wiring of the coil electrode 120, and sufficient conductive paste is not supplied to the via-hole conductor b9. As a result, in the coil conductor 120 shown in FIGS. 5 and 6, there is a possibility that a formation defect of the via-hole conductor b9 may occur.

On the other hand, in the electronic component 10 according to the present embodiment, the via hole conductor B9 is provided at the end of the coil electrode 20, as shown in FIG. The 20 wires are not extended. Therefore, when the coil electrode 20 is formed by the screen printing method, the conductive paste is used for forming the wiring of the coil electrode 20 and also for forming the via-hole conductor B9. As a result, in the electronic component 10, the problem of poor formation of the via-hole conductor B9 hardly occurs.

In order to make the effect more clear, the inventor of the present application evaluated the via hole conductor formation defect rate by performing the following experiment. FIG. 8 is a view showing the coil electrode 20 produced on the ceramic green sheet in the experiment.

In the experiment, as shown in FIG. 8, 19044 coil electrodes were formed by screen printing on a 90 mm × 90 mm ceramic green sheet having through holes at the positions of the via-hole conductors Ba to Bd. When even one via hole conductor formation defect occurred in 19044 coil electrodes, it was considered that the formation defect of the via hole conductor occurred in the ceramic green sheet. Such an operation was performed on 200 ceramic green sheets. Table 2 shows the experimental results.

As shown in Table 2, the formation defect rate of the via-hole conductors Ba and Bd located at the end of the coil electrode 20 was 0%. The formation defect rates of the via-hole conductors Bb and Bc located in the middle of the coil electrode 20 were 15% and 17%. Therefore, it can be understood that the formation failure rate of the via-hole conductor can be reduced when the via-hole conductor is provided at the end of the coil electrode than when the via-hole conductor is provided in the middle of the coil electrode. That is, in the electronic component 10, since the via-hole conductor B9 is provided at the end of the coil electrode 20, it can be understood that the formation failure of the via-hole conductor B9 hardly occurs.

(Other embodiments)
The electronic component according to the present invention is not limited to the above embodiments, and can be changed within the scope of the gist. For example, in FIG. 2, the contact portion C is formed thicker than the other portions of the

coil electrodes

18 and 20, but the contact portion C is not necessarily formed thick. For example, when the line width of the

coil electrodes

18 and 20 is sufficiently large, the contact portion C may not be formed thicker than the other portions of the

coil electrodes

18 and 20.

Here, the case where the coil electrode 20 of FIG. 9 is used will be described. The coil electrode 20 of FIG. 9 does not have a clear contact portion C, unlike the coil electrode 20 of FIG. Therefore, it is difficult to determine that the coil electrode 20 is configured to be connectable to the via-hole conductor B8 at a plurality of locations only by looking at the coil electrode 20 alone.

However, when the via-hole conductor B8 is connected to a portion (for example, points M and N in FIG. 9) other than the end opposite to the end to which the via-hole conductor B9 of the coil electrode 20 is connected, It can be said that the via-hole conductor B8 can be connected from the point where the via-hole conductor B8 is connected to the end portion where the via-hole conductor B9 is not connected. Therefore, when the via-hole conductor B8 is connected to the coil electrode 20 leaving the end portion to which the via-hole conductor B9 is not connected, the coil electrode 20 is configured to be connectable to the via-hole conductor B8 at a plurality of locations. Judge that

In the electronic component 10, the 3/4 turn coil electrode 18 is used. However, for example, a 5/6 turn coil electrode 18 or a 7/8 turn coil electrode 18 may be used.

In addition, in the manufacturing method of the electronic component 10, the electronic component 10 was produced by the sheet | seat lamination method, However, The manufacturing method of this electronic component 10 is not restricted to this. For example, the electronic component 10 may be manufactured by a printing method.

In the electronic component 10, as shown in FIG. 2, the coil electrode 18a is formed longer than the coil electrode 20, so that the first DC resistance from the via-hole conductor B3 to the via-hole conductor B4 is reduced. It is larger than the second DC resistance up to the conductor B9. However, the method of making the first DC resistance larger than the second DC resistance is not limited to this. For example, you may implement | achieve by adjusting the line | wire width and thickness of the coil electrode 18a and the coil electrode 20. FIG.

In the electronic component 10, both ends of the coil L are connected to the

external electrodes

14a and 14b by via-hole conductors B, respectively. However, either one end of the coil L may be connected to the external electrode 14a or the external electrode 14b by a lead portion connected to the coil conductor 18 on the magnetic layer 16.

The present invention is useful for an electronic component and a manufacturing method thereof, and is particularly excellent in that a disconnection between a via-hole conductor and a coil electrode can be prevented.

B1 to B13 Via hole conductor C1 to C16 Contact portion L Coil t1, t2 End portion 10 Electronic component 12

Laminated body

14a, 14b External electrode 16a-16m Magnetic layer 18a-18f, 20 Coil electrode

Claims

A plurality of coil electrodes constituting a coil;
A plurality of insulating layers laminated together with the plurality of coil electrodes to form a laminate;
Two external electrodes provided on the surface of the laminate, two connection portions for connecting the coil and the two external electrodes,
A via-hole conductor connecting the plurality of coil electrodes and having a shape in which the area of one end is larger than the area of the other end;
With
Of the coil electrodes provided at both ends in the stacking direction, the coil electrode having a relatively large DC resistance value between the connected via-hole conductor and the connecting portion is defined as a start electrode and connected. The coil electrode having a relatively small direct current resistance value between the via-hole conductor and the connecting portion is defined as an end electrode, and the coil electrode other than the start electrode and the end electrode is defined as an intermediate electrode. sometimes,
The start electrode is connected to the via-hole conductor connected to the intermediate electrode via the one end;
Electronic parts characterized by
The end electrode has a length equal to or longer than the number of turns obtained by subtracting the number of turns of the intermediate electrode from one turn, the via-hole conductor connected to the intermediate electrode, and the other end. Connected through
The electronic component according to claim 1.
The via-hole conductor connecting the end electrode and the intermediate electrode is formed integrally with the end electrode in the insulating layer;
The electronic component according to claim 1, wherein:
The end electrode overlaps with the via-hole conductor connected to the intermediate electrode when viewed in plan from the stacking direction;
The electronic component according to any one of claims 1 to 3, wherein:
The via-hole conductor connecting the start electrode and the intermediate electrode is formed integrally with the start electrode in the insulating layer;
The electronic component according to claim 1, wherein:
In the case where the direction from the end electrode toward the start electrode is defined as a first direction, in each via-hole conductor, the one end is positioned on the first direction side with respect to the other end. That
The electronic component according to claim 1, wherein:
The end electrode is configured to be connectable to the via-hole conductor at a plurality of locations;
The electronic component according to claim 1, wherein:
The end electrode has a portion that can be connected to the via-hole conductor has a thicker shape than other portions,
The electronic component according to claim 7.
The via-hole conductor connecting the end electrode and the intermediate electrode is connected to a portion other than both ends of the end electrode;
The electronic component according to claim 7, wherein:
The connecting portion is a via-hole conductor;
The electronic component according to claim 1, wherein:
The connecting portion is an extraction electrode provided on the insulating layer and connected to each of the start electrode or the end electrode;
The electronic component according to claim 1, wherein:
In the manufacturing method of the electronic component of Claim 1,
Forming the via-hole conductor in the insulating layer;
Forming the connecting portion in the insulating layer;
Forming the start electrode and the intermediate electrode on the insulating layer;
Forming the end electrode on the insulating layer;
The insulating layer in which the start electrode is formed, the insulating layer in which the end electrode is formed, and the intermediate electrode are formed so that the intermediate electrode is positioned between the start electrode and the end electrode Laminating insulating layers to form a laminate;
Providing
A method of manufacturing an electronic component characterized by the above.
The step of forming the via-hole conductor and the step of forming the start electrode and the intermediate electrode are performed simultaneously;
The method of manufacturing an electronic component according to claim 12.