JPS6033281B2 - resistor - Google Patents

Description

[Detailed description of the invention] The present invention relates to highly stable resistor materials.

In particular, the present invention relates to a resistor material useful for forming a resistor having high resistance and a small temperature coefficient of resistance. Highly stable and highly accurate resistor elements have come to be widely used not only as components for electronic computers but also for general-purpose electronic devices in connection with the recent increase in the precision of electronic devices.

As highly stable resistors with small temperature coefficients of resistance, metal nitrides such as nitride and alloys such as nichrome or chromium-silicon have been used. in this case,
A resistance temperature coefficient of 1,000 ppm/OC or less is widely used, and when particularly stability is required, an element with a resistance temperature coefficient of 100 ppm/°C or less is used. However, the resistivity of these materials is about 1 Pt (conductivity 1 and Q-1 skin-1), and it is difficult to lower the conductivity further and increase the resistivity without increasing the temperature coefficient of resistance. For example, the above materials were made into thin films, but in this case, increasing the resistivity tends to increase the temperature coefficient of resistance, and the resistivity achieved is 1000r○
It was below skin level. Higher resistivity is achieved with so-called cermet materials, which are a mixture of metal and insulator.
Cermet materials have large fluctuations in their characteristic values due to changes in composition, and are not necessarily suitable for manufacturing highly accurate resistors with uniform characteristics. As described above, it has been considered that it is essentially difficult to manufacture a resistor with high resistance, high stability, and high precision using conventional techniques. The present invention eliminates these drawbacks of conventional resistors and makes it possible to manufacture resistors with high resistance, high stability, and high precision. The content of this description will be explained below using examples. The present invention provides a tungsten bronze type composite oxide, for example, a composite oxide having the chemical formula MXNO03 consisting of an oxide of Nb metal and a metal element M other than NG metal, whose electrical properties change significantly depending on the content X of the metal element M. However, this is based on the discovery by the present inventors that highly stable resistance characteristics can be obtained by setting the content X appropriately.

Figure 1 shows the conductivity and resistance temperature characteristics of the Eu element content x when Eu element is used as the metal element M.
This figure shows the changes measured at room temperature. In the figure, 11 indicates the conductivity, and 12 indicates the rate of change in resistance with temperature. As shown in the figure, the Eu metal content X is 0.
．． It can be seen that the resistance temperature change rate is close to zero in a certain range of 6 to 0.8. For example, set the value of X to 0
．． 62<x<0.75, the resistance temperature change is ~1
,000ppm/00 or less. In this case the conductivity is 1
It can be seen that the resistivity is as small as P-Q-1 skin-1 and that the resistivity is ~1 Pi-Q-1 skin. Also 0.7 mi x 0.74 or 0
．． In the range of 625<x<0.64, the resistance temperature change becomes even smaller to 500 ppm/OC or less. In particular, it can be seen that zero temperature characteristics can be obtained at X30.72 or X30.63. In this case, the conductivity is 1 piQ-1
Since the resistivity at arc-1 is 1 pippus Q, a large value that could not be obtained with conventional resistive materials, it can be seen that this material is effective as a high-resistance material. FIG. 2 shows the results of measuring the temperature change in resistance of these materials in vacuum.

As shown in the figure, materials with near zero temperature characteristics exhibit zero temperature characteristics over a wide temperature range from low temperatures of -150 to high temperatures of 50 and 0. In this case, even when measured in air, no change in characteristics was observed up to 300 qo degrees, indicating that it can be fully used as a resistor. In the above example, a composite oxide of Nb and Eu was shown, but even if Sr, Ba, or Ca is used as the metal element to be composited with Nb, the same effect can be obtained without using Eu. It has been discovered that the same effect can be obtained even when two or more of these metal elements are selected and used.

Furthermore, the inventors have determined that the types of these additional metal elements are:
The ionic radius of the metal is important, and the optimal ionic radius is 1
It was found that it was in the range of ~1.5A.

Although the details of the reason are not clear, it is thought that this is because a tungsten bronze type composite oxide, which is a characteristic of the resistance material of the present invention, is formed only at this optimum ionic radius. Although the details of the reason why the zero temperature characteristic is obtained in this case are not clear, it is thought to be roughly as follows.

That is, FIG. 3 shows the relationship between the content of the metal element M and the crystal structure of the composite oxide for EU state 3. From the same figure, it can be seen that when the metal element content x is large, it is a cubic crystal type. In this case, Nb06 composed of Nb and ○
The basic skeleton is a regular octahedron, which is connected in a network, and Eu enters the gaps in the so-called velopskite structure. However, when the number of x decreases, this cubic crystal type is no longer maintained, and the structure changes to a regular crystal. This change in the horizontal structure of the crystal is related to electrical properties, and the cubic crystal type exhibits metallic electrical conduction, while the seminectral crystal type exhibits semiconductor-like electrical conduction, and the transition region of both structures is 0.625<×<0. It is thought that zero temperature characteristics can be obtained at .64. Also, 0.7<x<0.74
The zero-temperature characteristics in the range are considered to be due to the unique characteristics of the six-octahedral skeleton of N described above. Here, an example of the method for manufacturing the resistor of the present invention will be shown.

For example, a method of forming EU cutting b03 will be explained. First, Era 03 powder, metal niobium (Nb) powder, and niobium pentoxide (NQ05), which were heated in air and sufficiently dehydrated, were weighed in a ratio commensurate with the content of the metal oxide x, and mixed and press-molded. Afterwards, it is calcined in a vacuum for 900q02 hours. Furthermore, EUxN 3 is formed by firing these calcined products in a vacuum at a temperature of 1200 to 128000. When Sr, Ba, or Ca is used as the metal element M, it is preferable to use, for example, Sr203, Ba○, or Ca○ as a raw material in place of E-03. When using the resistance material of the present invention as a resistance element, it is preferable to mold the fired resistor into a rectangular parallelepiped, for example, and provide electrode pairs on the end faces of the rectangular parallelepiped. Furthermore, by forming a thick film using this fired product using a screen printing method, or using this fired product as a target to reduce the film thickness by cathode sputtering vapor deposition, a small-sized resistor element with high resistance can be obtained. In particular, when the film is made thin by cathode sputtering vapor deposition, the resistance value of the resistor element has little variation, it is possible to form a highly accurate element, and the resistor element is miniaturized, so it is particularly useful as a component of an electronic computer or the like. As is clear from the above explanation, the resistive material according to the present invention facilitates the manufacture of high resistance, high stability, and high precision resistive elements, which have been difficult to achieve in the past, and enables precision use in electronic computers, industrial measuring instruments, etc. It can be widely used to form resistive elements for general-purpose electronic devices, including electronic devices.

[Brief explanation of drawings]

1 and 2 are electrical characteristic diagrams of a resistor in an embodiment of the present invention, and FIG. 3 is an explanatory diagram showing the relationship between the crystal structure and electrical characteristics of the resistor. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. The chemical formula is represented by MXNbO_3, and M is Nb
A resistor whose main component is a chemical composition characterized by a metal element other than 2. The resistor according to claim 1, wherein the ionic radius of the metal element M is in the range of 1A to 1.5A. 3 In claim 2, the metal element M is
A resistor made of one or more of u, Sr, Ba, and Ca. 4 In claim 1, the chemical formula MXNbO
A resistor characterized in that the value of X in _3 is in the range of 0.62≦X≦0.75. 5 In claim 1, the chemical formula MXNbO
The value of X of _3 is 0.7≦X≦0.74 or 0.
A resistor characterized by being in the range of 625≦X≦0.64.