JP2003272923A - Electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component wherein an entire internal conduc tor of a conductive member has a nonlinear structure in a sintered body pro vided with the conductive member in a magnetic material, the bending strength is made large and a space is saved. <P>SOLUTION: The electronic component is provided with a rectangular substrate 1, a pair of external electrodes 3 formed on a first plane 1a of the substrate 1, and a conductive member 2 that is electrically connected with the external electrodes 3 in the substrate, and the first plane 1a and a plane including the conductive member 2 are formed non-parallel to each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounted on a circuit board or the like (especially an electronic component for noise suppression).

[0002]

2. Description of the Related Art In response to the trend of the multimedia age, high speed signal processing of information equipment is progressing. As a result, radiation noise is likely to occur inside electronic circuits, and various noise filters such as capacitors, inductors, and impeders are currently used as a countermeasure. Some impellers have a conductive material inside the magnetic material, and are often used as a type having a relatively high rated current.

This type of impeder can be manufactured by a lamination method or an extrusion method. Lamination method is to make a ceramic sheet with a doctor blade or an extruder.
A conductive member is arranged at a specific position on a ceramic sheet, and then the ceramic sheets are laminated and cut to have a specific size. The conductive material is present on two of the four cut surfaces facing each other, and the external electrode Connected to.

On the other hand, the extrusion method is to prepare a kneaded material of ceramic particles with a kneader, and insert the kneaded material of ceramic particles and the conductive member into different parts of the extrusion molding machine to obtain the kneaded material of ceramic particles and the conductive member. It is integrally molded into a specific shape and is cut into specific dimensions. A conductive member is present on the opposing cut surfaces and is connected to an external electrode.

As described above, the molded body containing the conductive member molded by the lamination method or the extrusion method is cut, baked, applied with external electrodes, baked, and plated with external electrodes. The form is such that a prismatic base body, a pair of external electrodes provided on opposing surfaces of the base body, and a conductive member electrically connected to the opposing external electrode surface through the inside of the base body from the external electrode on one surface side. I have it.

[0006]

A conventional electronic component and a method for manufacturing the same are such that an intermediate body extruded in a state in which a conductive material is embedded in a magnetic material is compressed at a substantially central portion in a longitudinal direction in a transverse direction thereof. It is characterized by reducing the height of the protruding parts of the conductive material that has been subjected to the treatment and the sintering treatment, and further mounting an external electrode that conducts to the conductive material. The purpose is to prevent the members from falling off, to prevent variations in the dimensions of the external electrodes, and to prevent disconnection between the external electrodes and the conductive member.

However, in the external electrode coating step, the shape affects the strength of the external electrode, and cracks occur due to bending of the substrate due to heat such as reflow during mounting. This is generally expressed as flexural strength, but as a result of the above, the entire fillet is destroyed when the element body is pulled over a certain displacement amount.

Further, when the substrate size is reduced and the array is narrowed due to space saving, it is possible to handle only the current size of the element body.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide an electronic component having an increased flexural strength and space saving.

[0010]

According to the present invention, a prismatic base body, a pair of external electrodes provided on a first surface of the base body, and an electrical connection to a pair of external electrodes provided in the base body are provided. The conductive member is provided so that the first surface and the surface including the conductive member are not parallel to each other.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 includes a prismatic base, a pair of external electrodes provided on the first surface of the base, and a pair of external electrodes provided in the base. By providing an electrically connected electrically conductive member, the first surface and the surface including the electrically conductive member are non-parallel, whereby a fillet of solder at the time of mounting is mounted. It is formed only at the contact point, and the upper part has less tensile displacement and is less likely to crack. In addition, the size of the base can be reduced to save space.

According to a second aspect of the invention, the conductive member includes an element portion and connecting portions provided at both ends of the element portion, and the connecting portion is an external electrode provided on the first surface. By using the electronic component according to the first aspect, the size of the base can be reduced and space can be saved.

According to a third aspect of the invention, the connecting portion has an external electrode provided on the first surface and a second electrode facing the first surface.
The electronic component according to claim 1, wherein the electronic component is connected to both of other external electrodes provided on the surface. On both the first and second surfaces, the solder fillet at the time of mounting is formed only at the mounting contact point, and the upper part has less tensile displacement and can be less likely to crack.

According to a fourth aspect of the present invention, the base is formed by laminating at least two sheets, and at least a part of a conductive member is formed between the two sheets.
3. The electronic component according to claim 2, wherein a surface obtained by laminating two sheets and the first surface are not parallel to each other, whereby the external electrode and the conductive member are connected to each other on the outer surface of the substrate. It can be done securely without pulling around.

Embodiments of the present invention will be described below with reference to FIGS.

1 and 2 are a perspective view and a cross-sectional view of an electronic component according to an embodiment of the present invention, respectively. In FIGS. 1 and 2, reference numeral 1 is a base, and the base 1 is formed in a prismatic shape,
Particularly preferably, a substantially rectangular parallelepiped shape is excellent in terms of mountability, and a rectangular cross section can reduce the mounting height when mounted on a circuit board or the like. Therefore, it is possible to downsize the electronic device and the like.

The base 1 is made of a magnetic material or a non-magnetic material, and a magnetic material is preferably used in the case of an electronic component that requires a particularly high impedance value, and a low impedance value is required. A nonmagnetic material is preferably used. When a magnetic material is used for the substrate 1, a sintered body of an oxide magnetic material such as ferrite is preferably used, and among the ferrite materials, Ni—Zn ferrite is preferably used, and further Ni—Zn Among Zn-based ferrites, Fe ₂ O ₃ —NiO—ZnO is preferably used. The specific composition of the Fe ₂ O ₃ —NiO—ZnO-based ferrite material is 40 to 60 mol%: 10 to 30 mol.
%: 20 to 40 mol%, and at times, a predetermined additive (Si etc.) may be mixed in a predetermined amount with a material composed of this composition. This material has a relative magnetic permeability of about 800, The resistance value is as large as 10 ⁶ Ω · cm, and a good impedance value can be obtained.

Reference numeral 2 denotes a conductive member provided in the substrate 1. The conductive member 2 is preferably composed of at least one of silver, nickel, palladium, copper, platinum and gold. Of these, it is particularly preferable to use silver alone or a silver alloy (for example, silver-nickel, silver-palladium).

As shown in FIG. 2, the conductive member 2 has a pair of connecting portions 2a and an element portion 2b provided between the pair of connecting portions 2a. The connecting portion 2a faces the base body 1. It is electrically connected to an external electrode 3 described later provided on the first surface 1a and the second surface 1b. Further, the surface forming the conductive member 2 is not parallel to the mounting surface, and is preferably formed so as to be substantially orthogonal to the mounting surface.

The element portion 2b is electrically connected to the pair of connecting portions 2a. The element portion 2b and the connecting portion 2a may be integrally formed or may be formed as separate members. For example, when the conductive member 2 is integrally formed by a printing method or a patterning method using a photoresist,
The element portion 2b and the pair of connecting portions 2a have an integral structure made of the same material. Further, the element portion 2b is formed in advance, and the connecting portion 2a is formed so as to contact both ends of the element portion 2b.
May be formed to have another configuration. Further, only the element portion 2b is composed of a linear body, and a pair of connecting portions 2 is formed on both ends thereof by printing or the like.
You may form a. Similarly, the element portion 2b and the connection portion 2a
May be composed of a continuous linear body.

When the conductive member 2 is composed of a linear body, a wire having a circular cross section with a diameter of 50 to 170 μm or a wire having a substantially square shape with one side of 50 to 170 μm is preferably used.

The element portion 2b is arranged in the substrate 1 in a substantially linear shape, or is embedded in a spiral shape (linear body) or meander shape (linear body or printed thin film), which is not shown. Good.

The external electrodes 3 are provided on the first surface 1a and the second surface 1b of the base body 1 and are in electrical contact with the connecting portion 2a of the conductive member 2. With this structure, mounting on either side is possible. Is possible. In addition, the external electrode 3 is attached to the first surface 1
Since it is possible to prevent the bonding material such as solder from protruding to the side surface of the electronic component by providing only a and the second surface 1b, it is effective for high-density mounting and the like.

Two external electrodes 3 are provided on the first surface 1a, and two external electrodes 3 are also provided on the second surface. The two external electrodes 3 provided on the first surface 1a are respectively provided on the substrate. The conductive member 2 forms a part of the circuit by being bonded to the land. Further, since the two external electrodes 3 are also provided on the second surface 1b, both the first surface 1a and the second surface 1b can be used as mounting surfaces. Also in this case,
By providing the element portion 2b in the substantially central portion of the base body 1, it is possible to prevent the characteristics from changing so much regardless of which of the first surface 1a and the second surface 1b is the mounting surface. Further, by forming the element portion 2b close to the first surface 1a or the second surface 1b side, the conductive member 2 can be mounted on the first surface 1a side and on the second surface 1b side. Since the line lengths are different, it is possible to provide an electronic component having two characteristics due to the difference in mounting surface with one element. That is, in FIG. 2, when the element portion 2b is formed on the side of the first surface 1a, when the first surface 1a is used as a mounting surface, the joint portion between the external electrode 3 and the element portion 2b at the connection portion 2a becomes short, and conversely. Second side 1
When b is the mounting surface, the joint between the external electrode 3 and the element portion becomes long, and therefore the line length of the conductive member 2 differs depending on the mounting surface, and as a result, the characteristics can be changed to some extent depending on the mounting surface.

Further, when the second surface 1b is mounted on the substrate, the first surface 1a does not face the substrate and is exposed to the outside. At this time, another electronic component, a jumper wire, or the like is joined between the two external electrodes 3 provided on the first surface 1a,
Alternatively, it can be joined to a land provided on another mounting substrate.

As the constituent material of the external electrode 3,
At least one of silver, gold, copper, nickel, or an alloy thereof is preferably used. Further, a joining material such as solder, or a lead-free solder composed of Sn alone or Sn and at least one of Ag, Cu, Zn, Bi and In is also suitably used. Further, the external electrode 3 may have a multi-layer structure. For example, a conductive metal such as silver is applied and baked, and then Ni or Ni- is added to improve weather resistance.
A Cr film is provided, and solder, lead-free solder, or the like is provided thereon.

Although two external electrodes 3 are provided on one surface, three or more external electrodes may be provided. Further, in the present embodiment, the external electrode 3 has a substantially quadrangular shape, but it may have a circular shape, an elliptical shape, a triangular shape, or a polygonal shape of pentagon or more. In this embodiment, for example, the external electrode 3 is formed with a predetermined distance from the peripheral portion of the first surface 1a so that the bonding material such as cream solder does not stick out. In order to make it large, it may extend to a part of the adjacent surface.

In the present embodiment, a pair of external electrodes 3 are provided on both the first surface 1a and the second surface 1b facing each other. However, the conductive member 2 is substantially U-shaped and the connecting portion 2a is one. It is also possible to provide the pair of external electrodes 3 on only one surface by adopting a configuration in which only one surface is exposed.

The characteristic parts of the electronic component constructed as described above will be described. The most commonly used method is as shown in FIG. 3, in which silver alone or silver and another alloy are applied to one end surface facing each other and baked. However, in such a structure, as shown in FIG. 4, the substrate is rolled by the heat of reflow at the time of mounting the substrate, and the element body or the external electrode is destroyed by the displacement. Therefore, as shown in FIGS. 1 and 2, by disposing the mounting portions of the external electrodes and the substrate only on the surfaces that are in contact with each other, the displacement due to bending can be reduced and the destruction can be suppressed as shown in FIG. Further, by bending the internal electrodes toward the external electrodes and arranging them, the outer shape can be shortened, and the size can be reduced.

At this time, as shown in FIG. 5, the length of the external electrode satisfies the relationship of L1 <P1 / 2 with respect to the length P1 ≦ 4.7 mm in the longitudinal direction of the first surface.

The external size (length: P1, width: P2, height P3) of the electronic component configured as described above is 0.9 mm≤P1≤4.7 mm 0.5 mm≤P2≤1.7 mm It is preferable that 0.5 mm ≦ P3 ≦ 1.2 mm.

Although the chip impeder has been described in the present embodiment, it can be applied to electronic parts such as other chip parts such as a chip resistor, a chip capacitor and a chip inductor.

With respect to the electronic component constructed as described above,
The manufacturing method will be described below.

First, as a second step, a vehicle in which a resin such as butyral, a phthalic acid type plasticizer, etc. and a solvent such as butyl acetate are dissolved and a ferrite powder of Ni, Zn, Cu, etc. are kneaded. The resulting magnetic slurry is applied to the upper surface of a support such as PET by a sheet forming method such as a doctor blade method, and then dried continuously to obtain a ceramic sheet 4 shown in FIG.

Next, as a second step, a predetermined pattern is formed on the ceramic sheet 4 with a conductive material such as silver or silver palladium by a method such as screen printing to obtain a ceramic sheet 6 on which the conductor pattern 5 is formed.

Next, in a third step, a ceramic sheet 4 on which no conductor is formed is laminated on an adhesive sheet that foams at about 130 ° C., and a support such as PET is peeled off. Place the ceramic sheet 4 on top of it so that the ceramic sheets are in contact with each other, and thermocompression-bond at about 60 to 120 ° C.
The support such as ET is peeled off. After repeating this lamination several times, the ceramic sheets 6 on which the conductor patterns 5 are formed are laminated in the same manner.

Next, the ceramic sheets 4 are laminated by pressure bonding in the same manner as above to obtain a laminated body.

As described above, the manufacturing method shown in FIG. 6 is a case where one element is disassembled for the sake of easy understanding. In actual manufacturing, a plurality of conductor patterns 5 are provided so that a plurality of elements can be taken. It is designed and manufactured so that it can be taken.

Next, as a fourth step, a plurality of the laminated bodies are cut into pieces of a predetermined size, the foamed sheet is heated and foamed at about 130 ° C. for about 5 minutes, and then separated into pieces. , Put them into a sheath such as ceramics, and put about 90
It was calcined at 0 ° C. for 3 hours.

Next, as a fifth step, a conductive paste such as silver is applied to the conductive pattern exposed portion 7 on the opposite end faces of the sintered body so as to be electrically connected to the conductive pattern 5 shown in FIG. External electrode 4 as shown in FIG. 1 after firing at 850 ° C.
To form.

Next, as a sixth step, nickel external plating, solder plating, or the like was applied to cover the external electrodes as needed to form the external electrodes in a multilayer structure.

[0042]

According to the present invention, a prismatic base body, a pair of external electrodes provided on the first surface of the base body, and a conductive member provided in the base body and electrically connected to the pair of external electrodes are provided. Prepare,
By configuring the first surface and the surface containing the conductive member to be non-parallel, by this, the solder fillet at the time of mounting is formed only at the mounting contact point, and the upper part has less displacement of tension and is less likely to crack. Become. In addition, the size of the base can be reduced to save space.

[Brief description of drawings]

FIG. 1 is a perspective view of an electronic component according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an electronic component according to an embodiment of the present invention.

FIG. 3 is a transverse cross-sectional view of an electronic component according to an embodiment of the present invention during mounting.

FIG. 4 is a transverse cross-sectional view of an electronic component according to an embodiment of the present invention during mounting.

FIG. 5 is a perspective view showing an electronic component according to an embodiment of the present invention.

FIG. 6 is a diagram showing a method for manufacturing an electronic component according to an embodiment of the present invention.

[Explanation of symbols]

1 base 1a First side 1b Second side 2 Conductive member 2a connection part 2b Element part 3 external electrodes 4 Ceramic sheet 5 conductor pattern 6 Ceramic sheet 7 Conductive pattern exposed part

Claims (4)

[Claims] 1. A prismatic substrate, a pair of external electrodes provided on a first surface of the substrate, and a conductive member provided in the substrate and electrically connected to the pair of external electrodes. ,
An electronic component, wherein the first surface and the surface including the conductive member are non-parallel to each other. 2. The conductive member includes an element portion and connecting portions provided at both ends of the element portion, and the connecting portion is connected to an external electrode provided on the first surface. The electronic component according to claim 1, wherein: 3. The connecting portion is connected to both the external electrode provided on the first surface and the other external electrode provided on the second surface facing the first surface. The electronic component according to claim 1. 4. The substrate is formed by laminating at least two sheets, at least a part of a conductive member is formed between the two sheets, and a surface obtained by pasting the two sheets together with the first sheet. The electronic component according to claim 2, wherein the surface is not parallel to the surface.