JP2003037010A - Chip laminated-type electronic component and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip laminated-type electronic component whose mounting properties with the land part of a printed board is satisfactory and which can easily be manufactured, and to provide the manufacturing method. SOLUTION: The laminated-type electronic part is provided with a substrate, a conductive member embedded in the substrate and an outer electrode which is arranged in the substrate and is conducted with the conductive member; and different regions are disposed at a part where the thickness of the conductive member is embedded in the substrate and a part where it is exposed to a substrate side and is brought into contact with the outer electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip laminated type electronic component that can be used as a noise suppression component for electronic equipment and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a chip type impedance element having an internal conductor provided in a through hole of a ferrite sintered body or an electronic component formed by laminating an internal conductor with a ferrite green sheet has been miniaturized and thinned as a noise countermeasure component. Used in many digital devices.

A conventional laminated chip-type impedance element will be described below. FIG. 5 is a perspective view showing the internal structure of a conventional electronic component. In FIG. 5, 11 is a magnetic ferrite, 12 is an internal conductor, and 13 is an external electrode that conducts with the internal conductor. In the conventional laminated chip-type impedance element configured as described above, the internal conductors 12 are printed on a plurality of magnetic ferrite sheets, laminated by lamination or the like, fired and integrated, and a conductive paste is applied to the end faces of the sintered body. The external electrodes are formed by baking.

However, in the above conventional structure, when the element shape becomes small, it becomes difficult to apply the conductive paste to the end face of the sintered body, and when the external electrode has two or more terminals on one side, the distance between terminals and the distance between terminals are kept constant. It has to be applied, which makes miniaturization difficult.

Further, when a lead-free glass frit is used as the glass frit forming the conductive paste as an environmental measure, the size of the external electrode is reduced with the downsizing of the element, so that the bonding strength between the magnetic ferrite and the external electrode is increased. There is a problem that it becomes low.

Therefore, the following conventional technique (Japanese Patent Laid-Open No. 2-3390) which improves the structure of the chip type impedance element is described.
No. 8 and Japanese Patent Laid-Open No. 7-161529) have been proposed. In the above-mentioned conventional technique, an electrically conductive paste is applied at a plurality of locations by intaglio printing on an end surface of a sintered body in which a magnetic ferrite substrate and an internal conductive member are fired and integrated, and baked to obtain an electronic component. Further, a conventional technique described later is to obtain an electronic component in which a dummy electrode is formed between an inner conductor of a magnetic ferrite substrate and an outer electrode.

[0007]

However, in the above conventional structure, since the organic solvent component of the conductor paste permeates the intaglio plate made of silicon rubber, the conductor paste is not applied to the end face of the sintered body with a uniform thickness. The bonding strength between the electrode 13 and the magnetic ferrite substrate 11 is not sufficient. In addition, there is a problem that mounting defects occur on a printed circuit board or the like due to uneven thickness of the external electrodes.

Further, in the conventional structure described later, dummy electrodes must be formed in the magnetic ferrite sheet in addition to the internal conductors by screen printing or the like, which causes problems such as unnecessary material cost and working time. there were.

Here, the external electrode is composed of a metal conductor powder and a glass frit, and the metal conductor and the ferrite substrate are joined by melting the glass frit. Although there are lead-based and barium-based glass frits, lead-free glass frits are becoming the mainstream due to recent environmental measures, but there is a problem in that the bonding strength with the substrate is inferior to that of lead-based glass frits.

Therefore, the present invention solves the above-mentioned conventional problems, and provides a chip laminated type electronic component in which the external electrode 13 and the magnetic ferrite substrate 11 are firmly joined and which can be easily manufactured, and a manufacturing method thereof. The purpose is to do.

[0011]

In order to solve the above-mentioned problems, a base, a film-shaped or sheet-shaped coil-shaped conductive member embedded in the base, and the conductive member provided on the base. In the laminated electronic component, the thickness of the conductive member is different between the part embedded in the base and the part exposed on the side surface of the base and in contact with the external electrode. When the thickness of the conductive member in the exposed portion is 1.0, the thickness of the conductive member in the portion exposed on the side surface of the base body and in contact with the external electrode is set in the range of 1.5 to 2.5.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 is a substrate,
A multilayer electronic component comprising a plurality of film-shaped or sheet-shaped coil-shaped conductive members embedded in the base, and external electrodes provided on the base and electrically connected to the conductive member. When the thickness of the member is different between the part embedded in the base and the part exposed on the side surface of the base and in contact with the external electrode, and the thickness of the conductive member in the part embedded in the base is 1.0, The chip laminated electronic component is characterized in that the thickness of the conductive member exposed on the side surface of the substrate and in contact with the external electrode is in the range of 1.5 to 2.5. Since the sintering reaction layer of the external electrode is formed widely, it is possible to strengthen the bonding between the base and the external electrode, and by providing a plurality of conductive members in the base, one component can have multiple functions. I can do things. further,
By embedding a coil-shaped conductive member in the base body, an inductor component can be formed and a function such as a noise countermeasure can be provided.

According to the second aspect of the present invention, a noise eliminating function can be provided by using the chip laminated electronic component according to the first aspect in which the substrate is made of a magnetic material.

According to the third aspect of the present invention, a high impedance element can be obtained by using the chip laminated type electronic component according to the first aspect in which the substrate is made of a magnetic material.

According to a fourth aspect of the present invention, the chip laminated electronic component according to the first aspect is characterized in that the base body has a substantially rectangular parallelepiped shape and a plurality of external electrodes are provided on a pair of opposing surfaces. The parts can be prevented from rolling and the mountability can be improved.

According to a fifth aspect of the invention, a ferrite sheet comprising a ferrite powder and a resin binder is provided.
A second step of providing a conductor pattern of a conductive member on the sheet by printing, plating transfer or the like; and a third step of providing a conductor through hole for electrically connecting the plurality of conductor patterns to the sheet. A fourth step of pressure-bonding and laminating a ferrite sheet, a sheet provided with a conductor pattern and a sheet having conductor through holes, and cutting the pressure-bonded laminated body to a predetermined size, and cutting the laminated body at 800 ° C to 1200 ° C. The fifth step of baking in
A sixth step in which the thickness of the conductive pattern is different between the portion embedded in the base and the portion exposed on the side surface of the base and in contact with the external electrode, and an external electrode which is conductive with the conductive pattern having a thickened contact portion is provided; By providing a method of manufacturing an electronic component including a seventh step of forming the external electrode in a multilayer structure and an eighth step of melting the multilayer structure portion of the external electrode,
Since the shape and appearance of the element are stable in terms of quality, it has an effect of being able to continuously manufacture a large amount by a simple process.

A specific example of an embodiment of the present invention will be described below with reference to the drawings.

1 to 3 are a perspective view, a sectional view and a perspective view of an electronic component according to an embodiment of the present invention, respectively.

1 to 3, reference numeral 21 denotes a base body, and the base body 21 is formed in a substantially rectangular parallelepiped or a substantially rectangular parallelepiped shape. Particularly preferably, it is excellent in mountability to have a substantially rectangular parallelepiped shape. When the cross-sectional shape is rectangular, the mounting height when mounted on a circuit board or the like can be reduced, so that electronic devices and the like can be downsized.

The base 21 is made of a magnetic material or a non-magnetic material, but a magnetic material is preferably used in the case of an electronic component that requires a high impedance value, and a low impedance value is required. Are preferably non-magnetic materials. When a magnetic material is used for the base 21, a fired body of an oxide magnetic material such as ferrite is preferably used, and among the ferrite materials, it is preferable to use Ni—Zn type ferrite, and Fe ₂ O ₃ — NiO-Zn
With a specific configuration of the O-based ferrite material, 40 to 60 m
ol%: 10 to 30 mol%: 20 to 40 mol%, and sometimes a predetermined additive (Cu or the like) may be mixed in a predetermined amount with a material having this composition, and the relative magnetic permeability is about 400, The specific resistance value is as large as 10 ⁶ Ω · cm, and a good impedance value can be obtained.

Reference numeral 31 denotes a conductive member provided between the end surfaces 4a and 4b of the base 21, and the conductive member 31 is preferably made of at least one of silver, copper, nickel and gold. Of these, it is particularly preferable to use silver alone or a silver alloy (for example, silver-palladium). In addition, the conductive member 3
1 is composed of a film-shaped or sheet-shaped coil shape, and a substantially rectangular wire rod having a line width of 3 to 200 μm and a line thickness of 1 to 80 μm is preferably used. A plurality of sheets are connected through the conductor through hole 6.

Reference numeral 41 denotes an external electrode which is provided on both end surfaces 4a and 4b of the base 21 and is in electrical contact with the conductive member 31, and the external electrode 41 includes the end surfaces 4a and 4b and the upper and lower surfaces 4c and 4c.
The structure is provided in a part of d, and this structure can increase the contact area with the circuit board,
The bondability with a land or the like can be improved.

Here, assuming that the thickness of the conductive member 31 embedded in the base is 1.0, the thickness of the conductive member 31a exposed on the side surface of the base and in contact with the external electrode is
The range of 1.1 to 2.5 is preferable. When the ratio is 1.1 or less, the bonding with the external electrode becomes close to a line contact, so the bonding strength is low. It is difficult and not preferable.

Particularly, by defining the thickness of the conductive member 31a in this way, it is effective when a plurality of external electrodes 41 are formed on the opposite side surfaces. That is, the presence of many external electrodes 41 increases the number of bonding points when one chip-type electronic component is mounted, and as a result, reliable bonding is required at each bonding point. Therefore, as described above, by defining the shape of the external electrode 41, reliable bonding of the external electrode 41 and the land can be realized, and for example, reliable mounting can be performed in a chip component having four or more external electrodes 41. Therefore, mounting defects can be reduced.

Here, the value of the adhesion strength with the solder at the land portion on the printed board is shown in (Table 1).

[0026]

[Table 1]

From the results of (Table 1), the electronic component of the present embodiment has an electrode adhesion strength improved by about 30% as compared with the comparative example, so that an electronic component having excellent mountability is obtained. I was able to.

As a constituent material of the external electrode 41, silver,
At least one of gold, copper, nickel, tin, or an alloy thereof is preferably used. Furthermore, a joining material such as solder or S
A lead-free solder composed of a simple substance of n or at least one of Sn and Ag, Cu, Zn, Bi and In is also preferably used. Further, the external electrode 41 may have a multi-layer structure. For example, a conductive metal such as silver is applied and baked, and then Ni--Sn is added to improve corrosion resistance.
Or Ni-Cr film is provided, and solder, lead-free solder, or the like is provided thereon.

The most commonly used method is to apply silver alone or silver and other alloys to the end faces 4a, 4b, 4c, 4d and bake. With such a structure, the manufacturing method is simple. Productivity and the like can be improved.

A method of manufacturing the electronic component having the above structure will be described below.

First, as a first step, a vehicle in which a resin such as butyral, a phthalic acid-based plasticizer, and a solvent such as butyl acetate are dissolved and a ferrite powder such as Ni, Zn, Cu, or the like are kneaded. The resulting magnetic slurry is applied on the upper surface of a support such as PET by a sheet forming method such as a doctor blade method, and then continuously dried to obtain a ceramic sheet 7a shown in FIG.

Next, in a second step, a predetermined pattern is formed on the ceramic sheet 7a by a method such as a plating transfer method using a conductive material such as silver or silver palladium to obtain the ceramic sheet 7b having the conductor pattern 77 formed thereon. .

Next, as a third step, through holes having a diameter of about 0.1 mm are formed in the ceramic sheet 7a by punching or the like. The through hole is filled with a conductive material such as silver or silver palladium by screen printing or the like and then dried to form the ceramic sheet 7 having the conductor through hole 70 of FIG.
get c.

Next, in a fourth step, a ceramic sheet 7a on which no conductor is formed is laminated on a pressure-sensitive adhesive sheet that foams at about 130 ° C. by peeling off a support such as PET. The ceramic sheet 7a was placed thereon so that the ceramic sheets from which the support such as PET had been peeled were in contact with each other, and thermocompression bonding was performed at about 60 ° C. to 120 ° C. for lamination. After repeating this lamination several times, a ceramic sheet 7 having a conductor pattern formed thereon
b is laminated by the same method.

Next, the ceramic sheet 7c is laminated, and thereafter, the ceramic sheet 7d on which the conductor pattern 77 electrically connected to the conductor through hole of the ceramic sheet 7c is formed is laminated in the same manner.

At this time, the conductor pattern and conductor through holes of the lower ceramic sheet 7b and the ceramic sheet 7 are formed.
The conductor pattern d is electrically connected.

Then, the ceramic sheets 7a are laminated by pressure bonding in the same manner as above to obtain a laminated body.

As described above, the manufacturing method in FIG. 4 is a case where one element is disassembled for the sake of easy understanding, and in the actual manufacturing, the conductor pattern 77 and the conductor through hole 70 are formed so that a plurality of elements can be taken. Are designed and manufactured so that a plurality of can be obtained.

Next, in a fifth 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.

Since the base and the conductive member formed by the plating transfer method have different firing shrinkage rates, the conductive member can be exposed from the side surface of the base. This exposed conductive member
If the thickness of the conductive member in the portion embedded in the base is set to 1.0 while removing burrs and the like from the element pieces by subsequent processing such as co-shaping in the porcelain pot, the external electrode is exposed. The thickness of the conductive member at the portion in contact with 1.1 to 2.
It was compressed into a range of 5.

Next, as a sixth step, a conductive paste such as silver is applied and dried on the opposite end faces of the sintered body so as to be electrically connected to the conductive pattern 77 of FIG. 4, and baked at about 850 ° C. The external electrode 41 is formed.

Next, in the seventh 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.

Next, as an eighth step, about 2 steps are performed in a reflow furnace.
The multilayer structure portion of the external electrode was melted at 60 ° C. to manufacture the electronic component 20.

[0044]

According to the present invention, a base, a plurality of film-shaped or sheet-shaped coil-shaped conductive members embedded in the base, and external electrodes provided on the base and electrically connected to the conductive member are provided. In the multilayer electronic component including, the thickness of the conductive member is different between the part embedded in the base and the part exposed on the side surface of the base and in contact with the external electrode, and the thickness of the part embedded in the base is different. When the thickness of the conductive member is 1.0, the thickness of the conductive member exposed on the side surface of the base body and in contact with the external electrode is set in the range of 1.1 to 2.5.
The sintering reaction layer of the conductive member and the external electrode can be widely formed, and the bond between the substrate and the external electrode can be strengthened.

[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 sectional view of an electronic component according to an embodiment of the present invention.

FIG. 3 is a perspective perspective view of an electronic component according to a surface embodiment of the present invention.

FIG. 4 is an exploded perspective view of a laminate according to the manufacturing method of the embodiment of the present invention.

FIG. 5 is a perspective view showing the internal structure of a conventional electronic component.

[Explanation of symbols]

11, 21 Base 12, 31, 31a Conductive member 13, 41 External electrode 70, conductor through hole 7a Ceramic sheet 7b Ceramic sheet with conductor pattern formed 7c Ceramic sheet with conductor through holes

Claims (5)

[Claims] 1. A chip provided with a base, a plurality of film-shaped or sheet-shaped coil-shaped conductive members embedded in the base, and external electrodes provided on the base and electrically connected to the conductive member. A multilayer electronic component, wherein the thickness of the conductive member is different between a portion embedded in the base and a portion exposed on the side surface of the base and in contact with an external electrode. 2. When the thickness of the conductive member embedded in the base is 1.0, the thickness of the conductive member exposed on the side surface of the base and in contact with the external electrode is 1.1 to. The chip laminated type electronic component according to claim 1, wherein the range is 2.5. 3. The chip laminated type electronic component according to claim 1, wherein the substrate is made of a magnetic material. 4. The chip multilayer electronic component according to claim 1, wherein the base has a substantially rectangular parallelepiped shape, and a plurality of external electrodes are provided on a pair of opposing surfaces. 5. A first step of providing a ferrite sheet made of ferrite powder and a resin binder, a second step of providing a conductor pattern of a conductive member on the sheet by plating transfer, and a plurality of the conductor patterns on the sheet. A third step of providing a conductor through hole to be electrically connected, a fourth step of pressure-bonding and laminating a sheet provided with a ferrite sheet, a conductor pattern, and a sheet having a conductor through-hole, and a press-laminated laminate having a predetermined size. And a fifth step of firing the cut laminated body at 800 ° C. to 1200 ° C., and the thickness of the conductive pattern is exposed at the portion embedded in the base and the side surface of the base to contact the external electrode. A sixth step of providing an external electrode which is different in part and which is electrically connected to the conductive pattern having a thickened contact part, and the external electrode having a multilayer structure. A seventh step, an eighth step of the manufacturing method of the stacked-chip electronic component having a melting the multilayer structure portion of the external electrode.