JP2000173857A - Electronic part, terminal electrode structure thereof and noise filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal electrode of an electronic part which is easily manufactured at a low cost, high in quality, capable of relaxing warpage of a printed board, dispensing with a plating process, and restraining an electronic part from bloating. SOLUTION: The terminal electrode structure of an electronic part is equipped with a pair of edge face electrodes 1 which are each provided on the opposed edge faces of a rectangular parallelepiped base body 4, and side electrodes 2 formed on the side of the base body 4 adjacent to the edge face electrodes 1. The side electrodes 3 are vertical electrodes 2 formed on the sides vertical to the edge face electrodes 1, and the total width of the vertical electrodes 3 is set from 2/10 to 8/10 as large as the width of the corresponding side of the base body 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal electrode structure of a surface-mounted laminated electronic component obtained by integrally sintering a conductive material and an oxide material, an electronic component having the structure, or a noise filter having the structure. About.

[0002]

2. Description of the Related Art A multilayer electronic component of a surface mount type is a small-sized electronic component obtained by forming an electrode pattern of silver or the like on a green sheet formed in advance using ceramics or soft ferrite, laminating the electrode patterns, and firing them integrally. Electronic components,
Widely used from low frequency to microwave band.

Such multilayer electronic components include, for example, single-function components such as multilayer chip capacitors, multilayer inductors, and multilayer transformers, and components that combine these functions. For example, noise filters include single-function filters and filters combining these functions.

[0004] These laminated electronic components usually have a rectangular outer shape, and external electrodes are usually formed on the entire surfaces at both ends in the longitudinal direction, and strip-shaped side electrodes are formed on the four side surfaces near the external electrodes. . The external electrode and the side electrode are formed so as to be connected to each other all over the boundary ridge line on the surface of the electronic component. Alternatively, for a component having three or more terminals, a side electrode may be provided on the side surface, for example, near the center.

The external electrodes and the side electrodes are usually made of silver, and a plating layer of nickel or the like is further formed thereon, and further a solder plating layer is formed thereon, that is, on the surface to form terminal electrodes. Usually, the underlying silver electrode is formed by printing and baking on each of the six surfaces of the semi-finished part.

The purpose of forming the side electrode near the end surface electrode is that without this, one terminal electrode of the electronic component rises when the electronic component is mounted on a circuit board and soldered, and the component rises ( Hereinafter, this phenomenon is referred to as a “rise phenomenon.” This phenomenon is likely to cause a rising phenomenon, a rising phenomenon, a Manhattan phenomenon, and the like, and is a serious quality defect. .

Further, when a large number of surface mount components are arranged on a printed circuit board, the printed circuit board tends to be warped. However, as the rising phenomenon is reduced, the tendency that the printed circuit board is likely to be warped becomes stronger, and a method for solving these two problems has been awaited.

On the other hand, there is an increasing demand for miniaturization of electronic components, and components having outer dimensions of 5 mm or less are generally used. Strict precision is required for each manufacturing process. Naturally, this was a major obstacle both in terms of manufacturing cost and quality. Further, there has been a situation that the above-mentioned "rise phenomenon" is more likely to occur as the size of the component is reduced.

From another viewpoint, there is a problem associated with the plating step. That is, for example, a large-scale facility is required for waste liquid treatment to pollution prevention, and the production cost of parts is naturally high. Therefore, it is desirable to omit the plating step as much as possible. Alternatively, in order to recover the underlying silver, it is necessary to remove the plating layer on the surface, and the recovery cost becomes enormous. There was a problem of going backwards.

[0010]

The problem to be solved by the present invention is one or more of the following problems. To provide a terminal electrode structure for electronic components that is easy to manufacture. To provide a terminal electrode structure for inexpensive electronic components. To provide a high quality terminal structure for electronic components. Suppress the rising phenomenon of electronic components. To provide an electronic component capable of reducing the warpage of a printed circuit board and suppressing the rising phenomenon. To provide a terminal electrode structure of an electronic component without a plating process. To provide a terminal electrode structure that contributes to resource reuse.

[0011]

Means for Solving the Problems As a result of earnest studies to solve the above-mentioned problems, the present inventors have conceived of a terminal electrode structure of an electronic component having a remarkably improved configuration. That is, in the first invention of the present application, the side electrode contacting the end face electrode is
A vertical electrode extending in a direction perpendicular to the end face electrodes and having at least one formed on each of the four side surfaces, and the total of the width of the vertical electrodes is 80 times the width of the corresponding side surface.
% Is a terminal electrode structure of an electronic component formed to be 20% or less.

The most novel and characteristic features of the present invention are:
The side electrode has one or more comb-like shapes, that is, the side electrode is constituted by a vertical electrode. With this structure, an effect of saving the amount of use of a noble metal such as silver is exerted.

In the present invention, when the total width of the vertical electrodes becomes larger than 80% of the width of the corresponding side surface, the effect of saving the amount of use of a noble metal such as silver is not remarkable. If it is less than 20%, suppression of the rising phenomenon of the components is insufficient. On the other hand, if it is less than 20%, the solder bonding strength of the component to a printed circuit board or the like is insufficient.

The second invention of the present application is a terminal electrode structure of an electronic component in which a conductive material and an oxide material are integrally sintered to form a side surface electrode of a laminated electronic component with a through-hole electrode. In this structure, the position of the side surface electrode may be formed not only near the both ends of the electronic component but also at an arbitrary position near the center, for example.

By adopting this structure, the side electrodes can be formed in the same step as the internal electrodes and can be formed simultaneously with the internal electrodes, so that it is not necessary to separately print the side electrodes as in the prior art, which is extremely economical. . If a numerically controlled drilling machine is used for the through hole for forming the through hole electrode, the positional accuracy will be improved. Furthermore, since parts can be separated based on the position of the through hole, variations in electrical characteristics are improved, and the quality improvement effect is remarkable. Furthermore, in the case of an electronic component having three or more terminals, it is easy to form electrodes on the side surfaces.

According to a third aspect of the present invention, at least one internal electrode of a laminated electronic component obtained by integrally sintering a conductive material and an oxide material is extended to a side surface of the electronic component and connected to the internal electrode. A terminal electrode structure of an electronic component in which a through-hole electrode is exposed on the side surface and a cross section of the internal electrode and the through-hole electrode is a side electrode.

The gist of the present invention is that an internal electrode is added to a part of the side electrode. With such a configuration, the rising phenomenon of the components is further reduced. Further, in the case of an electronic component having three or more terminals, a highly reliable electrode can be easily formed on the side surface. Another effect obtained by adopting such a configuration is that stray capacitance and stray inductance are reduced. As a result, there is an effect that the high-frequency characteristics are significantly improved.

According to a fourth aspect of the present invention, in the third aspect, the internal electrode extended to the side surface is formed by a frame electrode or a part of the frame electrode. By limiting in this way, the third invention of the present application has a more remarkable effect. If this is not a frame shape but a so-called solid electrode, it is not preferable because the strength of the component is reduced at this electrode position. On the other hand, in the magnetic circuit, the frame-shaped electrode has an effect of blocking magnetic flux at that portion, and thus has a function similar to that of the solid electrode in this sense. Further, in a circuit in which it is not desired to block magnetic flux at this portion, a part of the frame of the frame electrode may be cut off or a part of the frame electrode may be used.

According to a fifth aspect of the present invention, a land is arranged in a portion of the frame-shaped electrode or a part of the frame-shaped electrode according to the fourth invention, which is in contact with a through-hole electrode. With such a structure, the through-hole electrode more reliably functions as a side surface electrode.

All of these materials have high electric resistance,
It is suitable as a material for a laminated electronic component in which a material body and a conductive material are in direct contact. Further, these materials in the present invention need to be adjusted so as to be able to be fired at a temperature sufficiently low that the electrode material does not disappear.

The sixth invention of the present application is directed to the first invention to the fifth invention.
The oxide material in the terminal electrode structure of any one of the electronic components according to the present invention is composed of a ceramic material and / or a soft ferrite material, and the conductive material and / or the material of the terminal electrode is an alloy containing silver as a main component or It is composed of silver.

The soft ferrite material in the present invention includes, for example, NiCuZn, CuZn, NiZn,
Bi _{2 is} added to any of NiCu-based, Cu-based, and Ni-based materials.
It is a material to which a vitrification component such as O ₃ , PbO, B ₂ O ₃ , and V ₂ O ₅ is added.

Further, the soft ferrite is also effective as a known soft ferrite improving material constituted by substituting some of the constituent elements of the main component with another element and / or adding an auxiliary component. Not a change.

For example, a part of Fe or Ni alone or in combination with Al, Cr, Ti, Sn, Si, Sb, Li, Mg,
Mn, Co, Nb, Mo, etc., by substituting one or more of them, or using B, Ca,
The addition and use of a component composed of one or more constituent elements such as Ba, Sr, Y, Zr, In, Te, and W is part of the present invention.

Examples of the ceramic material include calcium zirconate (CaZrO ₃ ) and barium zirconate (B
aZrO ₃ ), strontium zirconate (SrZrO
₃ ), one or more selected from lead zirconate (PbZrO ₃ ), or an intermediate composition thereof, is not only effective as a general-purpose dielectric but also a low-loss dielectric for the 1 GHz band. This is based on the fact that an electronic component with low loss and high performance, for example, an LPF with excellent cutoff characteristics can be produced using the same.

The above ceramic material shows only the main phase component, but the low melting point oxide of the grain boundary phase, B
As in the case of the soft ferrite material, a vitrification component such as i ₂ O ₃ , PbO, B ₂ O ₃ , and V ₂ O ₅ may be added.

Further, the conductive material in the present invention is, for example, Ag (silver), Ag-Pd alloy, Ag-Pt alloy or the like.
g or Ag alloy. Furthermore, these Ag or Ag
B when alloy is an element other than Pd and Pt, for example, Ag paste containing glass frit (glass powder)
Needless to say, those containing a glass-forming element such as (boron) are also included.

The seventh invention of the present application is directed to the first invention to the sixth invention.
An electronic component having the terminal electrode structure of any one of the electronic components according to the present invention. The electronic component may further be a noise filter, and most effective if it is a 1 GHz band noise filter for reducing noise in the 1 GHz band. The invention from this viewpoint is the eighth invention of the present application.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on embodiments. FIG. 1 is a perspective view of one embodiment of an electronic component for explaining the present invention, and hatched portions are electrodes. FIG.
Are drawn schematically in order to ensure visibility, and the scale and number of each part are not accurate.

FIG. 1 has the following configuration. A terminal electrode made of a conductive material was formed on a rectangular element (4) made of an oxide material to obtain an electronic component. The terminal electrode of this electronic component includes an end face electrode (1) and a side face electrode (2).
The side electrode (2) was formed by a vertical electrode (3). Silver was used as the conductive material. Soft ferrite (11) was used as the oxide material.

[0031]

Next, a method of manufacturing the above electronic component will be described. In the following embodiments, the terminal electrode is formed by exposing silver and is not particularly subjected to plating, but may be subjected to plating. (Example 1) Soft ferrite (11) has relative permeability μ _r
Is about 15 and the sintering temperature is 900 ° C., which is NiCuZn ferrite to which Bi ₂ O ₃ is added. A plasticizer, a dispersant, and the like were added to the soft ferrite (11) powder and mixed to form a paste.

The soft ferrite (11) was formed into a sheet having a thickness of 100 μm with a doctor blade to obtain a green sheet. Through holes were formed at predetermined positions on the green sheet using a numerically controlled punch. Various silver electrode patterns were printed on the surface of the green sheet. As the silver, a commercially available silver paste was used. This silver paste contains a small amount of Pd, glass frit and other solvents in addition to silver.

These sheets were stacked in a stack of 20 layers so that the outermost layer of the sheet when formed into a silver solid coating pattern (5) was compressed at 10 MPa while heating at 100 ° C. to form a laminate. The laminate thus obtained was cut into 1 mm square.

The procedure for laminating the laminate and the procedure for forming through holes are as follows. That is, through-holes were arranged in the upper and lower three layers closer to the outermost layer at positions to be cut and so as to be connected in series at the time of lamination, that is, at positions corresponding to the side electrodes (2) of the chip after cutting. In addition, various samples were prepared in which the number of through holes formed at the cut position and the cross-sectional area of the cut portion were different.

The chip thus cut is subjected to a heat treatment in the air at 500 ° C. for 2 hours to remove the binder, and then to 900 ° C.
It baked in air | atmosphere on 1 degreeC conditions. The length (height) of the fired chip was approximately 1.6 mm, and the width of the side surface was approximately 0.8 mm. The length of the side electrode (3) formed by the through hole was about 0.25 mm. The width of the side electrode (3) is the through-hole electrode (10).
The width of the cross section or the width of the vertical electrode (3) was measured with a microscope.

A printed circuit board was separately prepared, the above-mentioned chip was mounted thereon, and soldered in a reflow furnace, and a rising phenomenon occurrence rate (hereinafter abbreviated as “occurrence rate”) out of 10,000 pieces was obtained. FIG. 2 is a graph showing the relationship between the occurrence rate and the ratio of the "cumulative value of the width of the vertical electrode (3)" to the "width of the side surface of the chip element" (hereinafter abbreviated as "side surface electrode ratio").
This side electrode ratio relates to one terminal electrode on the surface in contact with the printed circuit board. As is clear from FIG. 2, when the side surface electrode ratio is 20% or more, the rising phenomenon is not observed, and it is good.

FIG. 3 shows the relationship between the peel strength of the chip element from the printed circuit board and the side electrode ratio. The strength was determined by an intensity ratio (hereinafter abbreviated as “strength ratio”) to the case where the side surface electrode ratio was 100%. As a result, the intensity ratio was 20
% Or more was confirmed to be good. Further, when the side surface electrode ratio was 80% or less, it was found that the warpage of the printed circuit board after soldering the chip element was extremely reduced.

(Embodiment 2) FIG. 4 is an exploded perspective view showing a configuration according to Embodiment 2. In FIG. 4, the upper half is specifically shown and the lower half is omitted. FIG. 4 also shows parts (for example, electrodes) that are not visible from the outside of the component to facilitate understanding of the structure.

A so-called solid electrode (5) was formed on the first layer, which is the outermost layer of the laminate, and a land (7) electrode was provided on the frame-like electrode (6) on the second to fourth layers. An electrode pattern was formed. The first to fourth layers were connected by a vertical electrode (8) or the like. The fourth layer was connected to an internal circuit (12) below the fifth layer by a through-hole electrode (10). The internal circuit (12) is a coil formed by the internal electrode (9) and the through-hole electrode (10). However, other circuit structures may be used.

The other end of the internal circuit (12) was connected to the ninth layer by a through-hole electrode (10). The ninth and tenth layers were frame-like electrodes (6) with lands (7) similar to the third layer, and vertical electrodes (8) and through-hole electrodes (10) were arranged on the lands (7). The eleventh to twentieth layers have the same structure as the first to tenth layers. However, the first to tenth layers and the eleventh to twentieth layers were formed so as to be back-to-back and plane-symmetric.

The other components were the same as in Example 1 to produce a laminated chip. However, the diameter of the through hole is 0.32 mm (the diameter after firing is 0.25 mm), and after firing the frame electrode (6) with the land (7), the end face electrode (1) and the internal electrode (9). Is about 15μ thick
m (0.015 mm).

According to the second embodiment, the third terminal electrode could be easily formed near the center of the side surface by the vertical electrode (8). The third terminal electrode can be used, for example, as an intermediate tap. Alternatively, if the internal circuit (12) is changed, it can be used as the third terminal of a three-terminal LC filter. For example, from the ninth layer to the first
It is also easy to form a capacitance between two layers. 3
A typical example of a terminal LC filter is a T-type LPF useful as a noise filter.

According to the second embodiment, the rising phenomenon occurrence rate, the peel strength (strength ratio) with respect to the printed circuit board, and the warpage of the printed circuit board after soldering the chip element are all significantly larger than those of the first embodiment. I could improve it.

Example 3 The soft ferrite (11) in Example 2 was replaced with Bi ₂ O ₃ -added calcium zirconate (CaZr) which was a ceramic material.
In place of O ₃ ), the internal circuit (12) was replaced with a circuit composed of a coil and a capacitor, and the other parts and steps were made in the same manner as in Example 2.
The relative permittivity ε _r of the ceramic material is 29.

According to the third embodiment, a T-type three-terminal LPF having a cutoff frequency of about 250 MHz was obtained. When this LPF was mounted on an electronic circuit and used as a 1 GHz band noise filter, normal mode noise of a high frequency of 250 MHz or more (at least up to 3 GHz) could be attenuated.

[0046]

As described in detail above, according to the present invention, it was confirmed that at least one of the following effects was exhibited. That is, it is possible to provide a terminal electrode structure of an electronic component that is easy to manufacture. An inexpensive terminal electrode structure for an electronic component can be provided. A high-quality terminal electrode structure for electronic components can be provided. It is possible to provide an electronic component that can reduce the warpage of the printed circuit board and suppress the rising phenomenon. A terminal electrode structure of an electronic component in which a plating step is omitted can be provided. A terminal electrode structure that contributes to resource reuse can be provided. An excellent noise filter can be provided. In particular, an excellent noise filter can be provided in the 1 GHz band.

[Brief description of the drawings]

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

FIG. 2 is a graph related to one embodiment of the present invention.

FIG. 3 is a graph related to one embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a configuration of an electronic component according to one embodiment of the present invention.

[Explanation of symbols]

1 end face electrode, 2 side electrode, 3 vertical electrode, 4 rectangular element, 5 solid electrode, 6 frame electrode, 7 land,
8 (vertical electrode), 9 internal electrode, 10 through-hole electrode, 11 soft ferrite, 12 internal circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kirtika Amol 5200 Mikajiri, Kumagaya-shi, Saitama Hitachi Metals Co., Ltd. F-term in the Tottori Plant (reference) 5E070 AA05 AB01 CB03 CB13 CB17 CB18 CB20 DB02 EA01 EB03 5E317 AA01 AA24 BB04 BB14 BB18 BB19 BB24 CC15 CC22 CC25 CD21 CD31 GG07 GG16

Claims (8)

[Claims] 1. A terminal electrode structure of an electronic component having a pair of end face electrodes formed on both end faces facing each other and side face electrodes formed on respective side faces near the end face electrodes, wherein the side face electrodes are At least one vertical electrode formed on each side surface in a direction perpendicular to the end surface electrode, and the vertical electrode has a total width of 80% or less and 20% or more of the width of each corresponding side surface. A terminal electrode structure of an electronic component characterized by being formed as described above. 2. A terminal electrode structure for an electronic component, wherein a side electrode of a laminated electronic component obtained by integrally sintering a conductive material and an oxide material is formed by a through-hole electrode. 3. A laminated electronic component obtained by integrally sintering a conductive material and an oxide material, wherein at least one internal electrode extends to a side surface of the electronic component, and a through-hole electrode connected to the internal electrode is formed on the side surface. A terminal electrode structure for an electronic component, wherein a cross section of the internal electrode and the through-hole electrode is exposed as a side electrode. 4. The terminal electrode structure of an electronic component according to claim 3, wherein the internal electrode extended to the side surface is a frame electrode or a part of the frame electrode. 5. The frame-shaped electrode or a part of the frame-shaped electrode is a land-shaped framed electrode or a part of a frame-shaped electrode having a land at a portion in contact with a through-hole electrode. 5. The terminal electrode structure of the electronic component according to 4. 6. The oxide material is a ceramic material and / or a soft ferrite material, and the conductive material and / or the material of the terminal electrode is an alloy containing silver as a main component or silver. The terminal electrode structure of an electronic component according to any one of claims 1 to 5. 7. An electronic component having the terminal electrode structure according to claim 1. Description: 8. A noise filter having the terminal electrode structure according to any one of claims 1 to 6.