JP2000353932A - Electronic part and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic part having an electrode base film of which contact strength with ceramics is made superior, and also film thickness precision is made high, and a method for manufacturing this electronic part. SOLUTION: A vibrating electrode film 2a of this electronic part is formed through an electrode base film 21 on the surface of a piezoelectric ceramics substrate 1. The electrode base film 21 and the vibrating electrode film 2a are formed by a sputtering method. The electrode base film 21 is made of nickel/vanadium system alloy containing vanadium of 6.5-7.5 wt.%. Then, the film thickness of the electrode abase film 21 is set so as to be ranging from 0.1 to 0.3 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electronic component, in particular,
The present invention relates to an electronic component having an electrode film provided on a ceramic surface and a method for manufacturing the same.

[0002]

2. Description of the Related Art In an electronic component, when an electrode film is generally provided on a ceramic surface, Ag is generally used as a material of the electrode film.
And a noble metal such as Cu. At this time, an electrode base film is usually provided between the ceramic surface and the electrode film for the purpose of improving the adhesion strength between the electrode film and the ceramic and improving the resistance to soldering of the electrode film. Conventionally, as a material of the electrode base film, for example, an electrode paste obtained by adding a boride powder or a carbide powder to a base metal powder containing nickel as a main component, or a nickel-chromium alloy or nickel for a thin film. A copper-based alloy was used;

[0003]

However, among the conventional electrode underlayer materials, an electrode paste comprising a base metal powder containing nickel as a main component and a boride powder or a carbide powder is formed by a coating method. Therefore, there is a problem that the film thickness accuracy of the electrode base film is low. Nickel-chromium alloys and the like have poor etching properties, and it is preferable not to use chromium from the viewpoint of environmental issues. Further, the nickel-copper alloy had a slightly weaker adhesion strength.

An object of the present invention is to provide an electronic component having an electrode base film having excellent adhesion strength to ceramics and the like and high film thickness accuracy, and a method of manufacturing the same.

[0005]

In order to achieve the above object, an electronic component according to the present invention comprises a nickel-vanadium alloy containing 6.5 to 7.5% by weight of vanadium on a ceramic surface. The electrode film is provided via the electrode base film. Then, from the viewpoint of reliability, the thickness of the electrode base film is preferably 0.1 to 0.3 μm. In the above configuration, the nickel-vanadium-based alloy has a high adhesion strength to ceramics and has excellent resistance to solder erosion.

In the method of manufacturing an electronic component according to the present invention, vanadium is applied to the ceramic surface at 6.5 to 7.5.
An electrode base film made of a nickel-vanadium-based alloy containing a weight percent is formed by a sputtering method. By the above method, an electrode base film having high film thickness accuracy is formed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an electronic component and a method of manufacturing the same according to the present invention will be described with reference to the accompanying drawings. In the present embodiment, a piezoelectric component will be described as an example. However, any type of electronic component such as a capacitor or an inductor provided with an electrode film on a ceramic surface can be used.

[Structure of Piezoelectric Component] As shown in FIG. 1, a piezoelectric component 18 is composed of a piezoelectric ceramic substrate 1 provided with vibrating electrode films 2a and 2b on the front and back surfaces, and two exterior ceramic substrates 12 and 13. It is configured. A ceramic substrate such as PZT is used for the piezoelectric ceramic substrate 1, and ceramic substrates such as alumina are used for the exterior ceramic substrates 12 and 13. The vibrating electrode films 2a and 2b vibrate using the thickness shear vibration mode.

The piezoelectric ceramic substrate 1 is sandwiched between exterior ceramic substrates 12 and 13, and is formed into a laminate using an adhesive. A space for vibrating the vibrating electrode films 2a and 2b is secured by utilizing the thickness of the adhesive.

As shown in FIG. 2, external electrode films 14 and 15 are formed on the left and right sides of the laminate, respectively. The external electrode film 14 is electrically connected to the lead portion 3b of the vibration electrode film 2b, and the external electrode film 15 is connected to the lead portion 3 of the vibration electrode 2a.
a is electrically connected. Thus, the piezoelectric component 18 is obtained.

[Formation of Electrode Film] The formation of the vibrating electrode films 2a and 2b and the external electrode films 14 and 15 in the piezoelectric component 18 having the above configuration will be described in detail below. In the following description, the case where the vibrating electrode film 2a is formed on the surface of the piezoelectric ceramic substrate 1 will be described as an example, but the same applies to the other electrode films 2b, 14, and 15.

As shown in FIG. 3, the vibrating electrode film 2a is formed on the surface of the piezoelectric ceramic substrate 1 via an electrode base film 21 made of a nickel-vanadium alloy. Vanadium has excellent affinity and activation energy characteristics, and forms a strong chemical bond with oxygen contained in ceramics. Also, it has excellent resistance to solder erosion. The electrode base film 21 and the vibrating electrode film 2a are formed by a sputtering method which is known as a film forming method with high film thickness accuracy. Both film forming processes are continuous processes while maintaining a vacuum state. If the surface of the nickel-vanadium-based alloy of the electrode base film 21 is exposed to the atmosphere, the surface may be oxidized and the adhesion strength to the vibrating electrode film 2a may become unstable.

Here, as the characteristics of the electrode base film 21, it is preferable that the electrode base film 21 has a high etching speed and a low specific resistance.
It is set so as to be composed of a nickel-vanadium alloy containing 7.5% by weight. This alloy composition has better etching properties and specific resistance than a conventional nickel-chromium alloy. Further, this alloy composition has a saturation magnetization value equivalent to that of a nickel-chromium-based alloy containing 7% by weight of chromium, and does not make the electrode base film 21 a ferromagnetic material. The alloy composition is suitable for the non-magnetic magnetron sputtering apparatus used.

FIG. 4 shows a nickel-vanadium alloy O
It is a graph which shows an e-kG curve. In FIG. 4, curve 31 is for the case where the vanadium content is 7.5% by weight, curve 32 is for the case where the vanadium content is 7.0% by weight, and curve 33 is for the case where the vanadium content is 6.5% by weight. Is the case. It is empirically suggested that the saturation magnetization suitable for a magnetron sputtering apparatus for non-magnetic use is preferably about 0.8 kG or less at 7 Oe. Therefore, the content of vanadium was set to 7.5% by weight or less. On the other hand, the electrode base film 21
The adhesive strength of was adjusted to 6.5% by weight or more because the higher the vanadium content, the better.

Therefore, 6.5 to 7.5% by weight of vanadium is used as a sputtering target for the electrode underlayer 21.
The contained nickel-vanadium alloy material is used. This is because the sputtering method can easily form a film having substantially the same composition as the target composition. Other sputtering conditions are as shown below, for example. Sputtering gas: Ar (100%) Sputtering gas pressure: 5 × 10 ⁻³ Torr

If the piezoelectric ceramic substrate 1 is heated during sputtering, the adhesion strength between the electrode base film 21 and the piezoelectric ceramic substrate 1 can be further increased. However, when the piezoelectric ceramic substrate 1 is heated, the influence on the piezoelectric characteristics is unavoidable. Therefore, whether to heat the substrate 1 is determined in consideration of this point.

Under the above sputtering conditions, an electrode base film 21 is formed on the entire surface of the piezoelectric ceramic substrate 1. The film thickness of the electrode base film 21 depends on reliability such as mechanical strength and electrical characteristics (in addition, the lead terminals are connected to the vibrating electrode films 2a, 2a,
In the case of soldering to the lead portions 3a and 3b of b, or in the case of the electrode base film of the external electrode films 14 and 15, from the viewpoint of resistance to solder erosion, a predetermined solder material is used. Set to value. In the case of the present embodiment, from the graphs of changes in the amount of solder erosion of the electrode base film 21 due to high-temperature storage (150 ° C.) and soldering (350 ° C.) shown in FIGS. Thickness 0.1
０．３0.3 μm.

A vibrating electrode film 2a made of Ag, Cu, Ag-Pd or the like is further formed on the entire surface of the thus formed electrode base film 21 by a sputtering method. Thereafter, the piezoelectric ceramic substrate 1 is taken out of the sputtering device, and the electrode base film 21 and the vibration electrode film 2a are subjected to etching. Thus, the circular vibrating electrode film 2 a having the lead portion 3 a is formed on the surface of the piezoelectric ceramic substrate 1 via the electrode base film 21.

As described above, by using a nickel-vanadium-based alloy containing 6.5 to 7.5% by weight of vanadium as a material of the electrode base film 21, the adhesion strength to ceramics is increased, and the etching property and the like are improved. A vibrating electrode film 2a having excellent electrical characteristics and solder erosion resistance is obtained.

The electronic component and the method of manufacturing the same according to the present invention are not limited to the above embodiment, but can be variously modified within the scope of the invention. In the embodiment, the electrode base film 2 is formed on the entire surface of the piezoelectric ceramic substrate 1.
After forming the vibration electrode film 1 and the vibrating electrode film 2a, a necessary portion is removed by etching while leaving a necessary portion. However, even in a method in which a masking material having an opening of a desired shape is covered on the surface of the piezoelectric ceramic substrate 1 at the time of sputtering, and the electrode base film 21 and the vibration electrode film 2a are formed only on necessary portions. Good.

[0021]

As is apparent from the above description, according to the present invention, 6.5 to 4.5 vanadium is applied to the surface of the ceramic.
Since the electrode film is provided via an electrode base film made of a nickel-vanadium-based alloy containing 7.5% by weight, the electrode has high adhesion strength to ceramics, and is excellent in resistance to solder erosion, etching, and electric characteristics. A membrane can be obtained. Further, by forming an electrode base film made of a nickel-vanadium-based alloy containing 6.5 to 7.5% by weight of vanadium by a sputtering method, an electrode base film with high film thickness accuracy can be formed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of a piezoelectric component which is an embodiment of an electronic component according to the present invention.

FIG. 2 is a perspective view showing the appearance of the piezoelectric component shown in FIG.

FIG. 3 is a partially enlarged cross-sectional view showing a method of forming an electrode film on a ceramic surface.

FIG. 4 is a graph showing an Oe-kG curve of a nickel-vanadium alloy.

FIG. 5 is a graph showing a change in the amount of solder erosion of the electrode underlayer film due to high temperature storage.

FIG. 6 is a graph showing a change in the amount of solder erosion of an electrode base film due to soldering.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric ceramic substrate 2a, 2b ... Vibration electrode film 12, 13 ... Exterior ceramic substrate 14, 15 ... External electrode film 18 ... Piezoelectric component 21 ... Electrode base film

Claims (3)

[Claims] 1. Vanadium is applied to a ceramic surface.
An electronic component, wherein an electrode film is provided via an electrode base film made of a nickel-vanadium-based alloy containing 5 to 7.5% by weight. 2. The method according to claim 1, wherein said electrode underlayer has a thickness of 0.1 to 0.3.
The electronic component according to claim 1, wherein the thickness is μm. 3. Vanadium is applied to the ceramic surface.
A method for manufacturing an electronic component, comprising: forming an electrode base film made of a nickel-vanadium-based alloy containing 5 to 7.5% by weight by a sputtering method.