JPH02304904A - Platinum thin film temperature sensor and manufacture of same - Google Patents

Abstract

PURPOSE:To improve the characteristic to electric overload and prevent films from peeling by forming platinum temperature detecting resistor thin film layers on oxide film layers on the surface of an electric insulating substrate. CONSTITUTION:Iron is adhered to the surface of a mullite porcelain electric insulating substrate 1 by the magnetron sputtering method and heated in the air to form oxide films 2. Platinum films 3 are adhered on to said oxide films 2 by the magnetron sputtering method. The films 3 thus formed are processed by heat treatment to obtain a specific resistance temperature coefficient and tin-plated iron caps used as electrodes 4 are put on both ends of the substrate. Thereby the characteristic to electric overload improves and peeling of the platinum films 3 off the insulating substrate 1 is prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention provides temperature measurement devices and electronic circuits. White used for road temperature compensation, etc. Regarding gold thin film temperature sensor be.

[Conventional technology and problems The conventional platinum 4-film temperature sensor On the surface of electrical insulators such as lamic 4 platinum films by sputtering method etc. is formed. Do it like this The platinum thin film temperature sensor obtained by When the film thickness becomes thinner, electrical overload occurs. There was a weak tendency. Also, the film is thick In some cases, it is easy to peel off from electrical insulators. There was a tendency to

The present invention improves the conventional platinum mushroom membrane temperature sensor. without compromising the characteristics of the sensor. to improve the characteristics against air overload. At the same time, the film and electrical insulator are tightly bonded. Increases adhesion strength and prevents peeling of the skin film. It is intended to be

[Means for solving problems] Using conventional methods, platinum can be made electrically insulating. The thickness of the film deposited on the substrate The thin platinum film temperature sensor The film is electrically insulating. It has the disadvantage that it easily peels off from the body.

In the present invention, a thin film of iron, chromium, nickel, or a nickel-based alloy is first deposited on the surface of an electrically insulating substrate and then oxidized, and then a platinum film is deposited on the oxide film and heat treated to form an lf ! By obtaining a temperature resistance film, a thin film of iron, chromium, nickel, or a nickel-based alloy is first deposited on the surface of an electrically insulating substrate, and then platinum is deposited on top of this film, which is then heat-treated. The above problem was solved by creating a temperature resistance film.

[Example 1 The embodiment of the present invention is based on FIG. I will explain it to you.

In this example, the diameter is 1.5 Mullite of 3mm and length 6.0mm system porcelain as the electrically insulating substrate 1, On its surface, there is a magnetron spatula. After depositing iron using the ta method, atmospheric Heat this to 1000"C inside The film is oxidized [2 (first step) degree).

Next, a matrix is placed on top of the oxide film 2. White by Gnetron sputtering method Gold film 3 was applied to 3,000 people.

(Second step) The film formed in the above-mentioned first and second steps is heat treated at 1050°C to obtain a predetermined resistance film coefficient. After the heat treatment, the film has an inner diameter of 1.5 mm and a high length 1.4mm, thickness 0.25m
Electrodes 4 are made by inserting caps made of tin-plated iron into both ends. Using a laser beam, insert a spiral groove 5 with a pitch of 150 μm and a groove @ 60 μm until the specified resistance value is reached, and then use a solder-plated mild steel wire with a diameter of 0.65 mm as the lead wire 6, and connect it to the electrical N4 at both ends. Weld. Finally, a coating film 7 made of epoxy paint is applied to the substrate and electrodes to obtain a platinum-coated temperature sensor. The material deposited in the first step can also be chromium or Nilacel or a nickel-based alloy.

Samples prepared in this way (sample Characteristic test for 10 pieces of material A) and calculated the average value of the results. The values shown in Table 1 were obtained. For comparison Same film thickness and same shape. Regarding 10 pieces of conventional product (sample C) When we conducted a similar test, The average value of the results is shown in Table 1. Ta.

Test conditions The temperature coefficient of resistance was determined by measuring the resistance of the sample in oil at 0°C and 100°C, and calculating the rate of change in resistance per 1°C. Pulse voltage resistance was determined by applying a pulse voltage to the sample and determining the voltage value when the resistance value change exceeded 2%.

The pulse voltage was applied by applying a DC voltage to a 100 pF capacitor to charge it, then disconnecting the capacitor from the power supply, and applying the voltage across the capacitor to both ends of the sample.

[Example 2] An embodiment of the present invention will be described with reference to ε) based on FIG.

In this example, the diameter is 1.53 mm and the length is 6.5 mm.
A 0 mm thick mullite porcelain is used as the electrically insulating substrate 1. Iron, chromium, nickel or a nickel alloy is deposited on the surface by magnetron sputtering, and then heated to 1000°C in the atmosphere to form the film. is used as the oxide film 2 (first step).

Next, a 2 μm thick platinum film 3 is deposited on the oxide film 2 by magnetron sputtering. (Second step) In order to obtain a predetermined temperature coefficient of resistance, the film formed in the above-mentioned first and second steps was
Heat treatment is performed at 50°C.

After heat treatment, caps made of tin-plated iron with an inner diameter of 1.5 mm, a height of 1.4 mm, and a thickness of 0.25 mm are pushed into both ends to form the electrodes 4. The electrodes are heated with a laser beam at a pitch of 150 μm.
A spiral groove 5 having a groove width of 60 μm was inserted until a predetermined resistance value was reached. Thereafter, when the appearance of the platinum VII film was observed, no peeling of the platinum thin film from the insulating substrate was observed.

For comparison, here is a conventional product with the same film thickness and the same shape.
00 pieces, spiral grooves 5 with a pitch of 150 μm and grooves @60 μm were formed using a laser beam until a predetermined resistance value was reached. After this.

Observation of the appearance of the platinum thin film Peeling of platinum thin film from insulating substrate I saw 13 of them. Deposited in the first step The material is chromium or nickel or It is also possible to use nickel-based alloys.

[Example 3] An embodiment of the present invention will be described based on FIG.

In this embodiment, an electrically insulating substrate 1 is made of mullite porcelain having a diameter of 1.53 mm and a length of 6.0 mm, and iron is deposited on the surface thereof to form a coating 2 by magnetron sputtering.

(First step).

Next, platinum G3 is deposited on the film 2 by magnetron sputtering. (Step iJ2) The films formed in the above-mentioned first and second steps are subjected to heat treatment at 1050° C. in order to obtain a predetermined temperature coefficient of resistance.

After heat treatment, inner diameter 1.5mm, height 1.4mm,
Caps made of tin-plated iron with a thickness of 0.25 mm are inserted on both sides to form the electrodes 4, and the pitch is 150 μm using a laser beam.
After inserting a spiral groove 5 with a groove width of 60 μm until a predetermined resistance value is reached, a solder-plated soft #l wire with a diameter of 0.65 mm is used as a lead wire 6 and welded to the wires 41i4 at both ends. Finally, a coating film 7 made of epoxy paint is applied to the substrate and electrodes to obtain a platinum thin film temperature sensor. The material deposited in the first step can also be chromium or nickel or a nickel-based alloy.

Characteristic tests were conducted on 1011 of the samples thus prepared (sample B), and the average values of the results were determined, and the values shown in Table 1 were obtained. For comparison, a similar test was conducted on 10 conventional products (sample C) finished in the same thickness and shape, and the average values shown in Table 1 were obtained.

Test conditions The temperature coefficient of resistance was determined by measuring the resistance of the sample in oil at 0°C and 100°C, and calculating the rate of change in resistance per 1°C.

The pulse voltage withstand was determined by applying a pulse voltage to the sample and determining the voltage value when the resistance value change exceeded 2%.

The pulse voltage was applied by applying a DC voltage to a 100 pF capacitor to charge it, then disconnecting the capacitor from the power supply, and applying the voltage across the capacitor to both sides of the sample.

[Example 4 An embodiment of the present invention will be explained based on FIG. I will clarify.

In this example, mullite porcelain with a diameter of 1,53 mm and a length of 6.0 mm is used as the electrically insulating substrate 1, and 100 pieces of iron, chromium, nickel, or nickel are deposited on the surface by magnetron sputtering. A series alloy is deposited (step jl-).

Next, a 2 μm thick platinum film 3 is deposited on the oxide film 2 by magnetron sputtering. (Step @2) The films formed in the above-mentioned first and second steps are subjected to heat treatment at 1050° C. in order to obtain a predetermined temperature coefficient of resistance.

After heat treatment, inner diameter 1.5mm, height 1.4mm,
Insert caps made of tin-plated iron with thickness Q and 25 mm into both ends and turn on the electricity! ! ! 4, the pitch is 150 using laser light.
A spiral groove 5 having a groove width of 60 μm and a groove width of 60 μm was inserted until a predetermined resistance value was reached. Thereafter, when the appearance of the platinum 4 film was observed, no peeling of the platinum thin film from the insulating substrate was observed.

For comparison, the conventional product 1 has the same layer thickness and the same shape.
For 00 pieces, the pitch was 150μm using laser light.

A spiral groove 5 of 60 μm was inserted until a predetermined resistance value was reached. Thereafter, when the appearance of the platinum thin film was observed, 13111 pieces of peeling of the platinum thin film from the insulating substrate was observed. 1! The material deposited in one step can also be chromium or nickel or a nickel-based alloy.

[Effects of the present invention] As is clear from the results of Examples 1 to 4, the platinum thin film temperature sensor of the Examples according to the present invention has the following advantages in terms of resistance, resistance value, and temperature coefficient of resistance, regardless of the film thickness. Moreover, even if the thickness of the temperature-sensitive resistive film is thin, it has achieved the excellent effect of significantly improving the characteristics against electrical overload. Furthermore, the platinum film is prevented from peeling off from the insulating substrate, which tends to occur when the film is thick.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views of a temperature-sensitive electrical resistor according to an embodiment of the present invention.
Each symbol in the figure indicates the following. 1: Electrical insulation resistor 2: Iron or chromium or nickel or nickel-based alloy oxide film 3: Platinum temperature-sensitive resistance film 4: Cap electrode 5: Spiral groove 6: Lead wire 7: Coating film 8: Iron or chromium or nickel or Nickel alloy film slopel test results

Claims (1)

[Claims] 1. Having an oxide film layer of iron, chromium, nickel, or a nickel-based alloy on the surface of an electrically insulating substrate, and having a temperature-sensitive resistance thin film layer of platinum on the oxide film layer. A platinum thin film temperature sensor 2 characterized by having a film layer of iron, chromium, nickel or a nickel alloy of 500 Å or less on the surface of an electrically insulating substrate, and having a temperature sensitive resistance thin film layer of platinum on the film layer. The platinum thin film temperature sensor 3 is characterized by a first step of forming a film of iron, chromium, nickel or a nickel-based alloy on the surface of an electrically insulating substrate, and then oxidizing the film; Manufacturing method 4 of a platinum thin film temperature sensor, which comprises a second step of forming a platinum film to form a temperature-sensitive film, a film of iron, chromium, nickel or a nickel-based alloy with a thickness of 500 Å or less is formed on the surface of an electrically insulating substrate. A method for manufacturing a platinum thin film temperature sensor comprising a first step of forming a platinum film and a second step of forming a platinum film on this film to form a temperature sensitive film.