JPS6258521B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a temperature sensitive resistor.

Resistance thermometers using platinum have been established in JIS C1604 and are used as precision temperature sensors.
Although the accuracy is high and there is compatibility, the resistance value is low at 50Ω and 100Ω because platinum wire is used, which causes the problem that the peripheral circuit is complicated and is easily affected by peripheral circuit noise. It has a large shape and is also susceptible to vibration and shock. In addition, there is a limit to how thin platinum wire can be made, so a considerable amount of expensive platinum wire is used, and mass production is impossible because each platinum wire is wound around a shaft, etc. It had become quite expensive.

On the other hand, there is also a thick film type platinum temperature sensitive resistor whose resistance value is adjusted after screen printing with platinum-based ink, but because it uses a thick film, it is not possible to increase the resistance value, and it is still 50Ω and 100Ω. In addition, the shape is very large.

In addition, when using a thin film, it is possible to create a high resistance value, so it is possible to make a small one of about 5KΩ or 10KΩ, but it is not possible to create a shape in advance by printing etc., so it is necessary to create a shape after the film is deposited. The need arises. However, since platinum is very stable,
In ordinary chemical etching, it is necessary to immerse the photoresist in the etching solution for a long time, and the photoresist is often immersed or peeled off during the process, making it difficult to manufacture thin films. .

Therefore, an object of the present invention is to provide a method for manufacturing a temperature-sensitive resistor that can be manufactured easily and inexpensively using a metal thin film.

An embodiment of the present invention will be described based on FIGS. 1 to 4. In other words, as shown in Figure 1, the manufacturing method for this temperature-sensitive resistor is to first process a copper-nickel foil (a type of copper-nickel, copper:nickel = 45:55, thickness 20 μm) using a chemical etching method to form an extraction electrode. A base material 1 having forming portions 1a and 1b and a zigzag resistor forming portion 1c is created. In this case, the etching method was adopted because the width of the resistor forming part 1c and the width of the groove between the resistor forming parts 1c were set to 50 μm and 30 μm, respectively. It is also possible to create the base material 1 by a punching method using a die.

Next, the base material 1 is immersed in a plating solution, and a platinum thin film 2 is deposited on the surface of the base material 1 by electroless plating. In this case, the processing temperature is 40-60℃, about 60℃
A platinum thin film 2 with a thickness of 1 μm is obtained in minutes. Base material 1
Since there are the extraction electrode parts 1a, 1b and the resistor forming part 1c, the platinum thin film 2 also has the extraction electrode parts 2a, 2b and the resistor part 2c of the same dimensions. Note that the formation of adhesion of the platinum thin film 2 on the base material 1 is as follows:
In addition to the above-mentioned wet plating method, a so-called dry plating method such as a vacuum evaporation method or a sputtering method may also be used.

Next, as shown in FIG. 2, the platinum thin film 2 deposited on the base material 1 is placed on an insulating substrate 3 made of alumina.
The base material 1 is bonded to the outside using a silicone resin 4 having sufficient heat resistance. Note that when higher heat resistance is required, an inorganic adhesive such as a silicate adhesive (registered trademark: Aron Ceramic, etc.) can be used in place of the silicone resin 4. Further, as the insulating substrate 3, forsterite, mullite ceramic, etc. may be used in addition to alumina. In addition, beryllia porcelain can also be used especially for the purpose of improving thermal conductivity.

Next, the above-mentioned product is immersed in a ferric chloride solution of 36 to 42 degrees Baume to dissolve and remove the base material 1 as shown in FIG. Thereby, the platinum thin film 2 is exposed including the resistor portion 2c and the lead electrode portions 2a and 2b. This is used as a temperature-sensitive resistor.

Next, as shown in FIG. 4, electrode lead wires 5a and 5b are connected to the lead electrode portions 2a and 2b of the platinum thin film 2 by welding. Note that the electrode lead wires 5a, 5
The connection b can also be made by soldering or bonding with a conductive adhesive.

Next, a protective film 6 made of epoxy resin is applied to the surfaces of the insulating substrate 3 and the platinum thin film 2 to complete the manufacture of the temperature-sensitive resistor. Note that as the protective film 6, in place of the epoxy resin, in addition to organic paints such as silicone resins, inorganic paints can also be used.

The temperature-sensitive resistor manufactured in this way has a fifth
It has the temperature-sensitive resistance characteristics as shown in the figure, the high-temperature storage characteristics as shown in Figure 6 (conditions: 350℃ left in the atmosphere), and the high-temperature load characteristics as shown in Figure 7 (conditions: 70°C). ℃; 0.25W, 1.5 hours on, 0.5 hours off; 100Ω, 3800ppm/℃), and has humidity load characteristics as shown in Figure 8 (conditions: 40℃, 95%RH;
0.25W 1.5 hours on, 0.5 hours off; 100Ω,
3800ppm/℃).

Furthermore, this temperature-sensitive resistor has the following features.

(1) The variation in resistance value in the static state is small, and the variation in resistance value in the operating state is also small, so the error in the indicated temperature is small.

(2) Electrical resistance changes linearly with temperature changes.

(3) High stability.

(4) Small shapes and high resistance values can be created.

(5) Has a structure that is unlikely to change due to vibration or impact.

The method of manufacturing a temperature sensitive resistor of this embodiment has the following effects.

(A) Temperature-sensitive resistors using thin metal films such as platinum that are difficult to use with conventionally used groove cutting methods such as spiral cutting, difficult to etch, and difficult to form patterns even with lift-off methods. It is inexpensive and can be easily produced in large quantities.

(B) A small and lightweight temperature-sensitive resistor can be made.

(C) It is possible to make a temperature-sensitive resistor with strong vibration and shock resistance.

(D) Highly accurate, stable, and compatible temperature-sensitive resistors can be made.

In the example, a copper-nickel type foil was used as the base material 1, and a platinum thin film 2 was used as the temperature-sensitive resistor thin film, but the present invention is not limited to this. Various combinations are also possible, such as using a nickel film or the like.

As described above, the method for manufacturing a temperature-sensitive resistor of the present invention includes the steps of plating a metal plate processed into a predetermined shape with a metal of a different type from the metal plate to form a temperature-sensitive resistor thin film; The method includes the steps of bonding a temperature-sensitive resistor thin film formed on a metal plate to an insulating substrate so that the metal plate is on the outside, and dissolving and removing the metal plate. It has the advantage of being inexpensive and easy to manufacture.

[Brief explanation of the drawing]

1 to 4 are respectively perspective views for explaining one embodiment of the present invention, FIG. 5 is a temperature resistance characteristic diagram of the obtained temperature sensitive resistor, and FIG. 6 is a high temperature storage characteristic diagram, Figure 7 is also a high temperature load characteristic diagram.
FIG. 8 is also a diagram of moisture resistance load characteristics. 1... Base material (metal plate), 2... Platinum thin film (temperature sensitive resistance thin film), 3... Insulating substrate, 4... Silicone resin.

Claims (1)

[Claims] 1. A step of plating a metal plate processed into a predetermined shape with a metal of a different type from the metal plate to form a temperature-sensitive resistive thin film, and a step of plating the temperature-sensitive resistive thin film formed on the metal plate onto an insulating substrate. A method for manufacturing a temperature-sensitive resistor, comprising the steps of: adhering the metal plate so that the metal plate is on the outside; and melting and removing the metal plate.