JPH02302015A - Manufacture of thick-film electronic component - Google Patents

Abstract

PURPOSE:To provide sufficient adhesion to a substrate and a stable characteristic by a method wherein a flame-sprayed film of a raw material is formed on an insulating substrate by flame-spraying the raw material, this flame-sprayed film is irradiated with a laser beam and the flame-sprayed film is sintered. CONSTITUTION:Rectangular flame-sprayed films 2a, 2b composed of BaTiO3 are formed, by using a mask, on an Al2O3 insulating substrate 1 with dimensions of, e.g. 50X50X1mm under operating conditions of 34V and 850A by using a plasma flame-spraying apparatus. During this flame-spraying operation, a BaTiO3 powder whose particle diameter is 10 to 40mum is used. The flame- sprayed films 2a, 2b are respectively about 50mum thick. Then, the flame-sprayed films 2a, 2b are sintered by using a laser beam irradiation apparatus 3. As irradiation conditions of a laser beam during this process, an output of the laser beam is 1kW in an oscillation mode and the moving speed of the laser beam is 0.1m/min.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing thick film electronic components such as thick film resistors and thick film capacitors.

(Prior Art) Conventionally, a hybrid circuit, that is, a chip transistor,
Thick-film electronic components are particularly useful when forming electrical circuits on insulating substrates equipped with miniaturized electronic components such as chip resistors, thick-film resistors, chip capacitors, thick-film capacitors, diodes, and mini-flat ICs. Formation requires a complicated process. For example, in the case of a thick film capacitor, first, raw material reagents are wet-mixed to a desired composition and then dried to obtain 1 q of raw material powder. Next, add this raw material powder to 8
After calcining in an electric furnace at a temperature of about 00°C, it is pulverized into powder. A binder, vehicle, etc. are added to the capacitor material powder thus obtained to form a capacitor paste. After printing this paste in a predetermined shape using a screen printing method, etc., the entire board is approximately 900' thick.
C. in air or atmosphere to form a thick film capacitor.

In this way, forming thick film electronic components such as thick film capacitors requires complicated processes, and furthermore, since organic substances such as binders and vehicles are mixed with material powder, impurities such as carbon remain after firing. Therefore, there are also problems with reliability, such as not being able to obtain predetermined characteristics or changes in characteristics over time.

As an alternative to the method of forming thick-film electronic components using such a paste, there is a method of forming a thick-film resistor by thermal spraying, for example, as disclosed in JP-A-53-52995@Publication and JP-A-5
This is proposed in Japanese Patent No. 5-146906.

In this method, the powder material for the resistor is introduced into a flame generated by thermal plasma and melted, and the material for forming the resistor is adhered to a predetermined area on the substrate in the molten state. be. This method is different from the method described above in which the paste is applied by screen printing and then sintered, and the process is simplified, and it does not use organic substances such as binders.
Deterioration in reliability of electronic components due to residual impurities can be prevented.

However, thick film resistors formed by this thermal spraying method have unstable resistance characteristics, such as resistance values that change depending on environmental temperature, and thus lack reliability as electronic components. The reason for this instability in resistance characteristics is that in this formation method, metals, alloys, ceramics, etc. are sprayed singly or in a molten state onto an insulating substrate in the atmosphere. This is thought to be due to the presence of pores unique to thermal spraying.

In order to solve this problem, Japanese Patent Laid-Open No. 119701/1983 proposes that thermal spraying be carried out under a reduced pressure inert atmosphere. According to this publication, this thermal spraying method:
A resistor can be formed that substantially does not contain pores specific to solvents in the film. However, using a solvent under a reduced pressure inert atmosphere has disadvantages from the viewpoint of mass production, such as the necessity of batch processing and the increase in production equipment.

(Problems to be Solved by the Invention) As mentioned above, the conventional methods for manufacturing thick film electronic components are as follows:
There is a problem that electronic components having stable electrical characteristics cannot be formed, and furthermore, it is not suitable for mass production.

The object of the present invention is to have sufficient adhesion to the substrate, and
It is an object of the present invention to provide a method for manufacturing thick-film electronic components that can form thick-film electronic components having stable characteristics and is highly mass-producible.

[Structure of the invention] (V! Means and operation for solving the problem) The present invention has the following features:
This is a method for producing a thick film electronic component, which is characterized in that a raw material is thermally sprayed onto an insulating substrate to form a thermally sprayed coating of the raw material, and the thermally sprayed coating is irradiated with a laser beam to sinter the solvent coating.

In the thermal spraying process of the present invention, raw materials for thick film parts are thermally sprayed to a predetermined area and thickness. At this time, for the purpose of improving the adhesion of the formed thick film parts, it is preferable that the surface of the insulating substrate be roughened to some extent; however, from the viewpoint of improving the accuracy of the thickness of the thick film parts, The surface may be a smooth surface. Further, the raw material to be thermally sprayed does not necessarily have to have the same composition or structure as the material constituting the thick film component.

In consideration of changes in composition and structure due to reactions and evaporation that occur during thermal spraying or laser beam irradiation, either a mixed powder or a single compound powder may be used.

This thermal spraying is more effective if masking is applied to match the shape of the electronic component to be formed.

Further, the number of times of thermal spraying can be appropriately selected depending on the number of types of parts.

The irradiation process of the SEA light of the present invention not only sinteres the formed thermal sprayed coating, but also adjusts the irradiation conditions of the laser light such as the output sweep speed of the laser light, so that the irradiation process is stronger than that during sintering. Trimming can also be performed by irradiating energy-dense laser light to decompose, evaporate, and remove unnecessary sprayed coatings.

When sintering a thermally sprayed coating, it is efficient to irradiate and sinter only the portions of the thermally sprayed coating that are necessary as electronic components with laser light. Additionally, sintering the sprayed coating by irradiating it with laser light is more effective than firing it in an electric furnace.
Since it can be carried out in a short time and locally, not only can thermal effects on other parts be suppressed, but also a denser and thicker film can be obtained.

In the manufacturing method of the present invention, since the solvent coating formed by thermal spraying has sufficient adhesion to the insulating substrate, when the thermal spraying coating is fired, it is necessary to ensure the adhesion to the substrate of the thick film component to be formed. It is not necessary to melt the surface of the substrate at the same time. Therefore, the irradiation conditions of the 1F light for firing the thermally sprayed coating can be easily determined because it is only necessary to consider the firing conditions of the thermally sprayed coating. It is versatile and extremely efficient, regardless of the material of the insulating substrate used, such as an oxide substrate or an oxide substrate.

The present invention is particularly suitable for forming thick film capacitors and thick film resistors.

In the manufacturing method of the present invention, by thermally spraying raw materials onto an insulating substrate to form a thermally sprayed coating, not only is the adhesion of the thick-film electronic component to the substrate sufficient, but also there is no residual impurity such as organic binder. In addition, by irradiating this thermal sprayed coating with laser light and baking it, it is possible to form a thick film electronic component that is dense and has no pores.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. First, as shown in Figure 1, 50MX50/III
A, l! with a size of X 1 M! On the 203 insulating substrate (1), 34V,
Under operating conditions of 850A, rectangular shaped solvent solutions Ill (2a) and (2b) made of BaTiO3 were formed by masking. During this thermal spraying, BaTiO3 powder having a particle size of 10 to 40 μm was used. This thermal spray coating (2a
) and (2b) were each about 50 μm thick.

Next, the sprayed coatings (2a) and (2b) were sintered using a laser beam irradiation device (3) shown in FIG. The laser beam irradiation conditions at this time are that the output of the laser beam is 1 kW, the movement speed of the laser beam is 0.1 kW, and the moving speed of the laser beam is 0.1 kW.
m/min.

This laser light irradiation device (3) consists of a CO2 laser device, and a laser light source (4) that switches and emits either oscillation mode or single mode laser light.
) and a base (5) on which an insulating substrate (1) is placed. This laser light source (4) has a laser light (6) with a base (
5) Thermal spray coating (2a) of the insulating substrate (1) placed on it
, (2b) is controlled and moved by a drive device (not shown).

As a result of this laser light irradiation, a dense sintered layer of BaTiO3 was formed on the insulating substrate.

Furthermore, using a similar 1-noser light irradiation device (3), the laser light irradiation conditions were changed to a single mode output of 150W, 1
The edges of this sintered layer were trimmed at a travel speed of 0 m/min. As a result, a sintered layer with high dimensional accuracy was obtained. This sintered layer can be used as a thick film capacitor.

Note that the laser beam for trimming has a stronger energy density than the oscillation mode laser beam for sintering.

The time required for the above-mentioned thermal spraying, sintering, and trimming is about 1 hour, which is 1/1 compared to the conventional manufacturing process using paste.
It has been shortened to 0 or less.

In the above embodiment, the base that holds the insulating substrate in the laser beam irradiation device was fixed, but when baking or trimming multiple thermally sprayed coatings separated by a certain distance on a single insulating substrate, the thermally sprayed coatings are It is even more efficient to use a radar light irradiation device in which the base is also movable so that it can be moved to the laser light irradiation position.

[Effects of the Invention] As described above, according to the present invention, it is possible to form a thick film electronic component that has sufficient adhesion to a substrate and has stable characteristics, and which is highly mass-producible. A method for manufacturing electronic components can be provided.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a sprayed coating formed on an alumina insulating substrate based on the example, and FIG. 2 is a perspective view showing a laser beam irradiation device used in the example. DESCRIPTION OF SYMBOLS 1... Alumina insulating substrate, 2a, 2b... Solvent coating, 3... Laser light irradiation device, 4... Laser light source, 5... Base.

Claims (1)

[Claims] A method for producing a thick film electronic component, comprising: spraying a raw material onto an insulating substrate to form a sprayed coating of the raw material; and irradiating the sprayed coating with a laser beam to sinter the sprayed coating.