JPH0864469A - Electrode material and chiplike electronic component using the same - Google Patents

Abstract

PURPOSE: To obtain excellent solderability without forming a plated layer on a surface by forming thermosetting resin of phenol resin or acrylic resin. CONSTITUTION: An electrode material contain as indispensable ingredients conductive powder 8, thermosetting resin 7 and solvent, and as the resin 7, phenol resin or acrylic resin is used. The blending rate of the resin 7 is about 10 to 30% of the entire weight. Material 1 to be coated is, for example, coated with this material, heated for a predetermined time to cure the resin 7, then returned to the ambient temperature to an electrode layer 6. Thus, solder and side electrode layer can be sufficiently rigidly welded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode material and a chip-shaped electronic component such as a resistor, a capacitor and an oscillator using the same.

[0002]

2. Description of the Related Art Generally, a chip-shaped electronic component has a side surface electrode layer formed on its side surface, and the side surface electrode layer is used by being connected to a wiring such as a printed circuit board by soldering. The subsequent chip-shaped electronic component has the following configuration, for example, in the case of a chip resistor.

That is, as shown in the sectional view of FIG. 5, the chip resistor is formed of a rectangular parallelepiped insulating substrate 21 made of ceramic or the like and an upper surface of the insulating substrate 21 facing both ends thereof. A pair of upper surface electrode layers 22
And the upper surface electrode layer 2 on the lower surface of the insulating substrate 21.
2 and a pair of lower surface electrode layers 23 formed so as to face each other.
A resistance layer 24 formed so as to straddle the upper surface electrode layer 22, a protective layer 25 formed on the resistance layer 24,
Side electrode layers 2 formed on both sides of the insulating substrate 21 so as to connect the upper electrode layer 22 and the lower electrode layer 23.
6 and.

The side surface electrode layer 26 is formed by printing an Ag paste or an Ag-Pd paste mixed with a metal powder such as Ag or Pd using glass as a binder and firing it, or a thermosetting resin such as an epoxy resin as a binder. Is formed by printing and curing a conductive resin paste mixed with the above metal powder.

[0005]

However, in the chip-shaped electronic component having the above-mentioned conventional structure, the side surface electrode layer 26 is formed of Ag and glass, or Ag and thermosetting resin paste. Even if the side surface electrode layer 26 is directly soldered on the wiring of the printed circuit board made of glass-epoxy or the like, satisfactory alloying is not obtained between the side surface electrode layer 26 and the solder, and the fusion property is obtained. Is insufficient, connection failure may occur, or the chip-shaped electronic component may drop from a predetermined position on the printed board. In order to prevent this, it is necessary to obtain solderability by sequentially forming nickel and / or a solder plating layer 27 on the side surface electrode layer 26.

Providing the plating process for forming the plating layer 27 as described above not only increases the size of the manufacturing apparatus,
This causes a problem that the process becomes complicated. The present invention has been conceived under the circumstances as described above, and an object of the present invention is to provide an electrode material and a chip-shaped electronic component using the same, which has good solderability without forming a plating layer on the surface. It is intended.

[0007]

In order to solve the above problems, the present invention is an electrode material containing a conductive powder, a thermosetting resin and a solvent, wherein the thermosetting resin is a phenol resin or An electrode material characterized by being an acrylic resin can be provided. The present invention also provides a chip-shaped electronic component including an electrode layer containing the above electrode material.

The electrode material of the present invention contains conductive powder, a thermosetting resin and a solvent as essential components, and as the thermosetting resin, a phenol resin, an acrylic resin or the like is used.
The mixing ratio of the thermosetting resin is 1 based on the total weight.
It is about 0 to 30%, preferably about 15 to 25%. If the blending ratio of the thermosetting resin is less than 10%, the adhesion to the adherend when formed into an electrode layer is low, which is not preferable, while if it exceeds 30%, the conductivity when formed into an electrode layer is low, which is preferable. Absent.

The conductive powder of the present invention is not particularly limited, and examples thereof include Ag, Ni, Au, Pt, Cu,
Metal powders such as Al and Pd and powders having a metal coating layer on the surface thereof can be widely used, and one kind or two or more kinds thereof can be used. In the present invention, the conductive powder is Au, Pt, a mixture of Ag and Ni, or A
When a mixture of g, Pd and Ni is used, it is particularly preferable in terms of enhancing conductivity and solderability. When a plurality of kinds of the above metal powders are used, Au, Pt, Ag having high conductivity are used.
Etc. and Ni, Au, Pt, Pd, etc. having high solderability may be appropriately combined and blended so as to effectively obtain conductivity and solderability. The form of the conductive powder may be spherical, dendritic, flake-shaped, or amorphous, and dendritic is particularly preferable in terms of enhancing conductivity.
In addition, the average particle diameter of the conductive powder is preferably as small as possible in order to achieve high density and enhance conductivity, and is preferably about 30 μm or less, more preferably about 1 to 10 μm. The content of the conductive powder in the electrode material of the present invention is about 50 to 80%, preferably 55 to 70% based on the total weight.
It is a degree. When the compounding ratio of the conductive powder is less than 50%, the conductivity of the electrode layer becomes low, which is not preferable, while when it is more than 80%, the adhesion to the adherend when the electrode layer becomes low is not preferable. .

The conductive powder and the thermosetting resin are adjusted in viscosity with a solvent and sufficiently kneaded with a disper, a ball mill, a three-roll mill or the like to form a paste, which is used as an electrode material. The electrode material of the present invention is applied to, for example, an adherend, heated for a certain period of time to cure the thermosetting resin component, and then returned to room temperature to form an electrode layer. The solvent that can be used in the present invention is not particularly limited as long as it disperses or dissolves the resin component of the thermosetting resin and evaporates when heated to form the electrode material into the electrode layer. Examples thereof include various organic solvents such as terpineol, butyl carbitol acetate, and ethylene glycol dimethyl ether. The compounding ratio of the solvent in the electrode material of the present invention is about 5 to 15% based on the total weight. However, the blending amount of the solvent varies depending on the type of the solvent, the type and blending ratio of the resin components, the kneading conditions, etc., and it is preferable that the electrode material after the kneading is adjusted to have a viscosity within a coatable range. .

In the present invention, in addition to the above-mentioned essential components, various additives such as antioxidants, fillers, pigments, etc. for preventing the oxidation of the above-mentioned conductive powder are used as an electrode material for the conductivity and melting with the solder. You may use it in the range which does not reduce stickiness. Furthermore, in the chip-shaped electronic component provided with the electrode layer using the electrode material of the present invention, when forming the electrode layer, the temperature is about 150 to 250 ° C., more preferably about 180 to 230 ° C., and the time Is 5 to 3
It should be cured under heating conditions for about 0 minutes, more preferably for about 10 to 20 minutes.

[0012]

According to the present invention, since the phenol resin or the acrylic resin is used as the thermosetting resin in the electrode material, for example, this electrode material is heated at a heating temperature of about 150 to 250 degrees and a heating time. When the electrode layer is formed by heat-curing under the condition of about 5 to 30 minutes, the solvent contained in the electrode material is evaporated by the above-mentioned heating, and the heat-curing is present so as to cover the conductive powder. The conductive resin becomes a liquefied state and becomes extremely fluid in a short time from the paste state to the thermosetting, so that the conductive powder is partially exposed on the surface of the electrode material. When soldering is performed on the electrode layer formed by curing in such a state, the exposed conductive powder and the solder are alloyed and firmly fused.

When such an electrode material of the present invention is used as a side electrode layer of a chip resistor and this chip resistor is soldered onto the wiring of a printed circuit board, as described above, the solder and the surface of the side electrode layer are formed. Since the solder and the side surface electrode layer are sufficiently firmly fused by alloying with the conductive powder exposed on the surface, good soldering can be performed without the plating layer.

[0014]

EXAMPLES Examples of the present invention will now be described with reference to FIGS. 1 to 4, but the present invention is not limited to these examples. First, the electrode material used in this example and the adjustment of the electrode material for comparison therewith will be described. (Preparation of Electrode Material) (Example 1) Cu powder having an average particle diameter of 5 μm and Ag powder were mixed at a weight ratio of Cu: Ag = 9: 5, 57 wt% of metal powder, 28 wt% of phenol resin, and terpineol 1
5% by weight was sufficiently kneaded with a disper to obtain a paste-like electrode material.

(Example 2) Cu powder having an average particle diameter of 5 μm and Ag powder were mixed in a weight ratio of Cu: Ag = 9: 5 to obtain 78 wt% of metal powder, 12 wt% of phenol resin and 10 wt% of terpineol. The mixture was sufficiently kneaded with a disper to obtain a paste-like electrode material. (Example 3) 62% by weight of metal powder prepared by mixing Cu powder and Ag powder having an average particle diameter of 5 μm in a weight ratio of Cu: Ag = 9: 5, phenol resin 23% by weight and terpineol 1
5% by weight was sufficiently kneaded with a disper to obtain a paste-like electrode material.

(Example 4) Cu powder having an average particle diameter of 5 μm and Ag powder were mixed in a weight ratio of Cu: Ag = 9: 5 to obtain 73 wt% of metal powder, 17 wt% of phenol resin and 10 wt% of terpineol. The mixture was sufficiently kneaded with a disper to obtain a paste-like electrode material. (Comparative Example 1) 77% by weight of a metal powder obtained by mixing Ag powder and Ni powder having an average particle diameter of 5 μm in a weight ratio of Ag: Ni = 9: 5, 8% by weight of a phenol resin and 15 of terpineol.
A paste-like electrode material was obtained by sufficiently kneading the weight% with a disper.

(Comparative Example 2) 60% by weight of metal powder, 32% by weight of phenol resin and 8% by weight of terpineol were prepared by mixing Ag powder and Ni powder having an average particle diameter of 5 μm in a weight ratio of Ag: Ni = 9: 5. The mixture was sufficiently kneaded with a disper to obtain a paste-like electrode material. (Comparative Example 3) 70% by weight of a metal powder obtained by mixing Ag powder and Ni powder having an average particle diameter of 5 μm in a weight ratio of Ag: Ni = 9: 5, 20% by weight of an epoxy resin and 10 of terpineol.
A paste-like electrode material was obtained by sufficiently kneading the weight% with a disper. (Method of Forming Electrode Layer) Next, a method of forming the side surface electrode layer of the chip resistor by using the electrode materials obtained in Examples 1 to 3 and Comparative Examples 1 to 3 will be described.

First, as shown in a perspective view in FIG. 1 and a sectional view in FIG. 2, A is formed on both ends of the upper surface of a rectangular plate-shaped alumina substrate 1.
The g-glass type upper surface electrode layers 2 are formed so as to face each other. Then, Ag− is formed on the lower surface of the alumina substrate 1 so as to face the upper electrode layer 2 with the alumina substrate 1 interposed therebetween.
The glass-based lower surface electrode layer 3 is formed. Then, the resistance layer 4 is formed on the upper surface of the alumina substrate 1 so as to extend over the upper surface electrode layer 2. Further, a glass protective layer 5 is formed on the resistance layer 4 so as to cover the resistance layer 4 and expose the end portion side of the alumina substrate 1 of the upper surface electrode layer 2.

Here, each of the electrode materials of Examples and Comparative Examples is applied to both side surfaces of the alumina substrate 1 so as to partially cover the upper surface electrode layer 2 and the lower surface electrode layer 3. Then, the chip resistor in the above-mentioned state is heated at a peak temperature of 200 ° C. in a hot air circulation type tunnel heating furnace (a state in which hot air is blown and circulated in the heating furnace).
Heat for 5 minutes.

In this case, when the side electrode layer 6 is heated to the curing temperature of the thermosetting resin 7, the thermosetting resin 8 begins to cure while the solvent evaporates. Here, when the thermosetting resin 7 is a phenol resin,
As shown in the schematic cross-sectional view in FIG. 3 (a), since this is liquefied and has a very high fluidity for a short period from the paste state to the curing, the conductivity in the electrode material is reduced. The nature powder 8 is exposed and exposed.

However, when the thermosetting resin 7 is an epoxy resin, as shown in the schematic sectional view of FIG.
Since the solvent evaporates and hardens at the same time, the conductive powder 8 in the electrode material remains covered with the epoxy resin. After this, the solvent 7 is almost completely evaporated and the thermosetting resin 7 is almost completely hardened. Further, it is taken out from the heating furnace in an environment where the ambient temperature is room temperature, and the side surface electrode layer 6 connecting the upper surface electrode layer 2 and the lower surface electrode layer 3 is formed with a layer thickness of about 20 μm.

In the present embodiment, when forming the side surface electrode layer 6, the chip resistor is heated at a peak temperature of 200 ° C. for 15 minutes, but the heating temperature is not limited to this. The heating temperature may be in the range of 150 to 250 degrees and the heating time may be in the range of 5 to 30 minutes. More preferably, the heating temperature may be in the range of 180 to 230 degrees and the heating time may be in the range of 10 to 20 minutes.

In the present embodiment, the side surface electrode layer 6
Is cured by heating in a hot air circulation type tunnel type heating furnace, but it is not limited to this, and may be heated by various methods such as a far infrared heating furnace and a hot air circulation type oven. Further, although the thickness of the side surface electrode layer 6 is set to about 20 μm in this embodiment, the thickness is not limited to this, and it is preferably about 10 μm or more. (Comparison of electrode layers) When the adhesion of the side surface electrode layer 6 of the chip resistor thus obtained to the alumina substrate 1 was examined, the electrode materials of Examples 1 to 4 and Comparative Examples 2 to 3 were used. All of them were good, but the adhesiveness of Comparative Example 1 was poor.

Next, Examples 1 to 4 and Comparative Examples 1 to 3
As shown in FIGS. 4A and 4B, each of the chip resistors using the electrode material obtained in step 1 is soldered to the wiring 91 of the printed board 9 at 200 to 250 ° C.
4 (a) shows Example 3 and FIG. 4 (b) shows Comparative Example 3). The results are as follows.

The chip resistors using Examples 1 to 4 are
The adhesiveness between the side surface electrode layer 6 and the solder 10 was excellent, and those of Examples 3 and 4 were particularly excellent. However, the chip resistors using Comparative Examples 1 to 3 were not preferable because of poor fusion property with the solder 10.
Further, the chip resistors using Examples 1 to 4 and Comparative Example 1 were excellent in the conductivity between the side surface electrode layer 6 and the solder 10. However, the chip resistors using Comparative Examples 2 and 3 were inferior in conductivity.

As described above, according to the electrode material of the present invention, an electrode layer having good solderability can be obtained without forming a plating layer. Therefore, the chip-shaped electronic component using the electrode material of the present invention can be satisfactorily soldered without the need to provide a plating layer on the electrode layer serving as a terminal for external connection. That is, it is possible to reduce the size of the manufacturing apparatus for a chip-shaped electronic component and simplify the manufacturing process without the need for a plating process after the step of forming the side electrode layer of the conventional chip-shaped electronic component.

In the present embodiment, the phenol resin is used as the thermosetting resin, but even when the acrylic resin is used, it is possible to obtain substantially the same effects as the above. Further, in the present embodiment, the chip resistor is used as the chip-shaped electronic component, but the present invention is not limited to this, and a chip type multilayer ceramic capacitor,
It is widely applied to a chip-shaped electronic component having an electrode layer used for soldering, such as a solid electrolytic capacitor and an oscillator.

[Brief description of drawings]

FIG. 1 is a perspective view showing a chip resistor according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line XX of the chip resistor of FIG.

FIG. 3 is a schematic cross-sectional view for explaining the state of the electrode material when the electrode material of the present invention is applied to the side surface of the substrate and the electrode material is heated.

FIG. 4 is a schematic cross-sectional view illustrating a state when the chip resistor obtained in FIG. 3 is soldered to a printed board.

FIG. 5 is a cross-sectional view showing a conventional chip resistor.

[Explanation of symbols]

 1 Alumina substrate 2 Upper surface electrode layer 3 Lower surface electrode layer 4 Resistance layer 5 Protective layer 6 Side surface electrode layer 7 Thermosetting resin 8 Conductive powder 9 Printed circuit board 10 Solder

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H05K 1/09 D 7726-4E

Claims (2)

[Claims] 1. An electrode material containing an electrically conductive powder, a thermosetting resin and a solvent, wherein the thermosetting resin is a phenol resin or an acrylic resin. 2. A chip-shaped electronic component, comprising an electrode layer containing the electrode material according to claim 1.