JPS58130502A - Temperature depending resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a substrate made of an insulating metal oxide and a thin platinum layer as a resistive material, and after coating the resistor with the resistive material, heat treatment is performed in an oxygen-containing atmosphere. of,
Concerning humidity-dependent resistance.

In the case of known temperature-dependent resistors of this type, a thin platinum layer is deposited directly onto the insulating substrate to a thickness of 1-10 μm by vacuum evaporation or by cathodic sputtering. To produce a zigzag pattern, a photoconductive lacquer is coated onto a platinum film, partially masked, exposed and developed. The desired conductor tracks are then produced by ion etching or other methods. The adjustment of the conductor track to a constant resistance value takes place by means of a laser beam. In order to achieve particularly high temperature coefficients of electrical resistance, the thin platinum layer is coated by cathodic sintering in an argon-oxygen mixture and postheated in this way at temperatures above 800°C, particularly in the range El 000-1200°C. In the case of a resistor formed on the surface, there is a risk that the platinum film will peel off easily. For example, a platinum film is peeled off from a substrate by pulling on soldered conductive wires. The platinum layer can also be removed by peeling off the adhesive tape that has been adhered to it.The purpose of the present invention is to obtain the above-mentioned temperature-dependent resistance when the platinum layer is attached to the substrate.

This object is solved according to the invention by coating the substrate with an intermediate layer of metal which bonds the substrate and the platinum layer between the substrate and the platinum layer.

In this case, the platinum layer resists at least the force required to break the soldered wire.

In particular, the intermediate layer contains titanium. This ensures particularly high bonding strength.

Advantageously, the intermediate layer is deposited on the substrate to form an intimate bond with the substrate.

In this case, the intermediate layer has a thickness of approximately 2 to 5 nm, in particular approximately 2°5 nm.
It has a thickness of m. Such a small thickness is sufficient to ensure reliable support of the platinum layer to the intermediate layer.

The platinum layer can have a thickness of about 0.4 to 1.2 μm (and can have a thickness of about 1 μm. This range of layer thicknesses not only increases the required strength of the bond, but also often leads to long conductors). Since changes in conductor resistance do not have a large effect on measurements made through the conductor, it is possible to obtain the necessary relatively high resistance values.

The platinum layer can be applied to the intermediate layer by vapor deposition or cathode sintering/gluing. In this case as well, a relatively high bonding strength between the platinum layer and the intermediate layer, in particular the titanium intermediate layer, should be ensured.

The substrate material is in particular aluminum oxide.

This material not only acts as a good insulator, but also ensures a high bonding strength between the substrate and the intermediate layer, especially titanium.

The resistor can then be heat treated in air. In particular, this method largely prevents resistance value errors due to heat or deterioration from the nominal value at the respective temperature.

By heat-treating the resistor at a temperature of approximately 1200 to 1425 DEG C. and approximately 1300 DEG C., the change in resistance value from its nominal value becomes particularly small.

In this case, a heat treatment time of only about 1 hour is sufficient.

Next, the present invention will be explained with reference to the drawings.

The temperature dependent resistance shown in FIGS. 1 and 2 is
, an intermediate layer 2 and a platinum layer 3, the substrate 1 consists of an insulating metal oxide layer, in particular aluminum oxide, but can also consist of other metal oxides, such as magnesium oxide.

The intermediate layer 2 consists of metal, in particular titanium, but copper can also be used. This layer is approximately 2-5 nm thick (approximately 2 to 5 nm thick).
．． It has a thickness of 5 nm and can be applied to the substrate l by vapor deposition or cathodic sputtering, in particular after heating the substrate 1 to approximately 250°C.

The platinum layer forms a temperature-dependent resistance material, approximately O14-1.2
It has a thickness i of .mu.m, in particular 0.5 to 1 .mu.m.

The platinum layer is formed in a zigzag shape by the photoresist method like the intermediate layer 2, and is deposited on the intermediate layer 2 by vapor deposition or cathode film.
ξ Covered by ivy.

However, the zigzag shape can also be produced by burning away with a laser beam.

The resistor, which has been finished to form a zigzag shape, is first heated in an oxygen-containing atmosphere (in air at about 1100 to 1425°C, especially at about 120°C).
Heat treated at a temperature of 0-1300°C. In order to keep the deviation of the resistance value from the nominal value at the respective operating temperature very small, a temperature of approximately 13
It is 00℃. After heat treatment, a zigzag shape is formed, and then a fine adjustment of the resistance value is also carried out by burning out with a laser beam. Subsequently, another post-heat treatment is performed.

The following Table 1 shows various examples of resistors having the structure according to the principles shown in Figures 1 and 2, which differ in heat treatment temperature, platinum layer thickness and intermediate layer metal, and whose nominal resistance value is 0°
and 100 ohms. The intermediate layer thickness is 2.5 nm. The heat treatment was carried out in atmospheric air for about 1 hour. Substrate 1 is made of aluminum oxide.

Table 1 Example Heat treatment temperature (℃) Platinum layer thickness (μm)
Intermediate layer 500 038-05 Copper, 2S vine ring b 850 200 d1400 Titanium, vapor deposition 1
375 o, s f 1425 1g
1375 1h
13001 FIG. 3 shows the relationship between resistance error and operating temperature for various examples in Table 1. Furthermore, the two tolerance ranges ±A and ±A according to the DIN standard are shown in the figure.
B is drawn with a broken line or chain line, and the tolerance range ±A is narrower than B in the tolerance range.

As shown in Figure 3, the deviation from the nominal value exceeds the tolerance ranges A and B very quickly for examples a, b and C, but at least 150°C to +140°C for examples d and e.
In examples f, g and h, the deviation is even smaller at temperatures above at least 0° C. and remains within the tolerance range A over a larger temperature range. In this case, typical deviations are minimal up to at least about 145°C. Approximately -30℃~+1 which is used very often
Within the temperature measuring range of 80° C. the example is therefore optimal.

The bonding strength between the platinum layer 2 and the substrate 1 is in all cases so high that the solder breaks when the conductive wire soldered to the platinum layer 2 is pulled, and in all cases the bonding strength between the platinum layer 2 and the substrate 1 is so high that the solder breaks when the conductive wire soldered to the platinum layer 2 is pulled. No peeling of the platinum layer occurred.

Table 2 below shows two advantageous basic examples for manufacturing the resistors according to the invention, two only in the /e-turn (for example zigzag) formation method, one by laser method and the other by photoresist method. The difference is based on the law.

Table 2 Laser method Photoresist method 1 Cleaning of substrate 1. Substrate cleaning 2 Titanium deposition,
Layer thickness approx. 252 photoconductive lacquer coating m 1 μm 11, installation of connecting conductor 12, encapsulation in the capsule Variations from the embodiment described above can also be made within the scope of the invention. For example, zirconium can be used instead of copper or titanium in the intermediate layer 2.

[Brief explanation of the drawing]

1 is a sectional view of a resistor according to the invention, FIG. 2 is a plan view thereof, and FIG. 3 is a diagram showing error curves of various embodiments of the resistor according to the invention. l... Substrate, 2... Intermediate layer, 3... Platinum layer 1 side cleaning l (Contents: 2 No changes) Figure 1, 3 Figure 2 Procedural amendment form (G type) 111 (Total: 51 tons) , March 9th, 4!I-+i'l Director General 1・1111)
8 No. 2, Name of Invention Temperature-dependent Resistance J Supplement 11 Relationship with μ Note Name of Patent Applicant Name Da/Fosny Nis 4 Agent 0 Supplementary Drawings 7 Also in Supplement 11 As shown in the attached sheet, engraving of the drawing of ``11'' (no change in content) 9-

Claims (1)

[Claims] 1. A substrate made of a P-molten metal oxide and a thin platinum layer as a resistor material, and a resistor is coated with the resistor material.
In temperature-dependent resistance heat treatment in an oxygen-containing atmosphere, an intermediate layer consisting of a gold plate bonding the substrate (1) and the platinum layer (3) is placed between the substrate (1) and the platinum layer (3). A temperature-dependent resistor characterized in that it is coated on top. 2. The resistor according to claim 1, wherein the intermediate layer (2) comprises titanium. 3. The resistor according to claim 1 or 2, wherein the intermediate layer (2) is deposited on the substrate (1). 4. Resistor according to one of claims 1 to 3, in which the intermediate layer (2) has a thickness of 2 to 5 nm. 5. Resistor according to one of claims 1 to 4, in which the platinum layer (3) has a thickness of 0.4 to 1.2 μm. 6. Resistor according to one of the claims 1 to 5, in which the platinum layer (3) is coated on the intermediate layer (2) by vapor deposition or cathodic scattering. 7. The resistor according to one of claims 1 to 6, in which the substrate material is aluminum oxide; 8, the resistor according to one of claims 1 to 7, heat-treated in air; resistance,. 9. Resistor according to one of claims 1 to 8, heat treated at a temperature of 1200 to 1425[deg.]. 10. A resistor according to one of claims 1 to 9 which has been heat treated for 1 hour.