JP2011137774A - Sheet resistance measurement terminal and measuring lead employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem with measurement using a sheet resistance measurement terminal based on a usual JIS K7194, wherein a resistivity correction factor needs to be multiplied after the measurement to correct a measured value, a device cost or a labor is required and an erroneous recognition may arise. <P>SOLUTION: In the measurement terminal used for measuring a resistance of a thin film by using a four terminal method, positions of four measurement terminals are fixed so that a value obtained by dividing a measured voltage value by a current value is equal to a sheet resistance value of the thin film. Thus, a read value of the measurement directly shows the sheet resistance value. A device for calculation is not necessary and the erroneous recognition during the measurement is prevented. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

      The present invention relates to a measurement terminal used when measuring the sheet resistance of a thin film using a four-terminal method, and a measurement lead using this measurement terminal.

  Conductive thin films are used not only in display devices and touch panels, but in various industrial fields. Various film forming apparatuses are used for manufacturing the conductive thin film, and in the quality evaluation of the conductive thin film, a sheet resistance value, which is a guideline indicating the electric resistance of the film, is measured.

  The sheet resistance value is measured by passing a constant current between two points and measuring the voltage value between electrodes separated by a certain distance. The voltage value is determined by Ohm's law (resistance value = voltage value / current value). Calculated based on the value divided by the current value. As a method for measuring the sheet resistance value, it is known that the 4-terminal method is superior to the simple 2-terminal method.

  This is because in the two-terminal method, the current value and the voltage value are measured at the same terminal, so that it is directly affected by the contact resistance between the terminal and the substance. In the four-terminal method, this effect does not occur because the voltage value is measured with a separate dedicated terminal.

  And as a measuring method of sheet resistance value by this 4 terminal method, nonpatent literature 1 is known as a reliable method.

  In this case, as shown in FIG. 2, the current application terminal 1a, the voltage measurement terminal 2a, the voltage measurement terminal 2b, and the current application terminal 1b are arranged at equal intervals (5 mm).

  A constant current value is passed between the current application terminal 1a and the current application terminal 1b, and the voltage value between the voltage measurement terminal 2a and the voltage measurement terminal 2b is measured.

  In this measurement method, data on the influence of the thickness and shape of various thin films on a standard sample size 50 mm × 80 mm plate is taken, and thereby the value of the resistivity correction coefficient is obtained.

  In order to obtain the sheet resistance value, it is necessary to divide the voltage value (V) measured using four terminals by the current value (I) and apply a resistivity correction coefficient. The resistivity correction coefficient varies depending on the shape and size of the data and the measurement position. However, when the sample is sufficiently large (standard sample size), the film thickness of the industrially formed thin film is sufficiently thin relative to the sample (1. 1 mm or less), the sheet resistance value is almost correct if 4.2 is used as the correction coefficient in the measurement at the center.

Japanese Industrial Standard K7194 "Resistivity Test Method for Conductive Plastics Using 4-Probe Method"

  In the measurement using the Japanese Industrial Standard K7194, in order to obtain the actual sheet resistance value, it is necessary to always multiply the data output by the measurement by a resistivity correction coefficient.

  In the case of correction by human manual calculation, the central part is measured and the measured value is simply multiplied by 4.2. This is because the resistivity correction coefficient may be a constant value (4.2) if the measurement object is a film (1.1 mm or less) sufficiently thinner than the standard sample size and the measurement location is limited to the center. is there.

  In other words, it is necessary to correct by installing an arithmetic circuit in the measuring device, or it is necessary to correct the output value by human calculation. In the case of the device, a dedicated machine is required and the cost is high. It was the cause.

  The present invention is intended to solve the problem of the conventional measurement terminal, and connects a measurement lead having a sheet resistance measurement terminal according to the present invention to a digital multimeter capable of four-terminal measurement. It is intended that the reading value of the resistance value of the digital multimeter indicates the sheet resistance value as it is.

  The present invention provides a measuring terminal characterized in that a voltage value obtained by dividing the position of four terminals for measurement by a current value is fixed so that a sheet resistance value of a thin film is equal. It is.

  Moreover, it is desirable that the measuring terminal according to the present invention uses a noble metal material on the surface.

  Furthermore, the measuring terminal according to the present invention preferably includes a spring mechanism in the measuring terminal.

  The measurement terminal according to the present invention is fixed so that the voltage value obtained by dividing the position of the four terminals for measurement divided by the current value is equal to the sheet resistance value of the thin film. For this reason, if the measurement lead using the measurement terminal according to the present invention is connected to the digital multimeter to measure the resistance of the four terminals, the sheet resistance value can be displayed as it is in the digital multimeter.

It is a top view which shows the terminal for sheet resistance measurement by this invention. It is a top view which shows the conventional terminal for sheet resistance measurement. It is a perspective view which shows the measurement lead for sheet resistance measurement by this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is a plan view showing a sheet resistance measuring terminal of the present invention. In a conventional sheet resistance measuring terminal, four terminals are arranged at equal intervals in the order of a current applying terminal 1b, a voltage measuring terminal 2b, a voltage measuring terminal 2a, and a current applying terminal 1a.

  This order is the same as that of the conventional sheet resistance measuring terminal shown in FIG. 2, but in the sheet resistance measuring terminal according to the present invention, the interval between the terminals is experimentally adjusted, and the voltage measuring terminal 2a and The terminal is fixed at a position where the voltage value measured at the voltage measurement terminal 2b divided by the current value flowing through the current application terminal 1a and the current application terminal 1b is equal to the sheet resistance value of the thin film.

  FIG. 3 shows an example of a measurement lead prepared using the sheet resistance measurement terminal according to the present invention.

  The resistance measurement terminal is fixed at a specific position by the terminal fixing member 3, and the connection terminal 6 is connected by the connection line 5 in order to connect the resistance measurement terminal and the digital multimeter. These connecting wires 5 are collected by the protective member 4.

  Each of the resistance measurement terminals has a spring mechanism so that when the resistance measurement terminal is pressed against the thin film to be measured, the resistance measurement terminal comes into contact with the film at a constant pressure that does not break the film. In order to reduce the contact resistance between the film and the terminal and to take into account the corrosion resistance, the resistance measuring terminal is precious metal plated.

  By using this measurement lead and performing resistance measurement by a 4-terminal method with a digital multimeter, the resistance measurement value directly indicates the sheet resistance value of the film.

  Here, the connecting wires 5 are gathered by the protective member 4, but the protective member 4 is not necessarily required. In addition, it is desirable to have a spring mechanism and noble metal plating at the measurement terminal, but this is not always necessary. Therefore, the scope of the present invention is not limited by these.

  As an example of the present invention, a device in which the distance between the current application terminal 1b and the voltage measurement terminal 2b was 2 mm and the distance between the voltage measurement terminal 2a and the current application terminal 1a was 2 mm in FIG.

  Next, as a result of resistance measurement by the four-terminal method while experimentally changing the distance between the voltage measuring terminal 2b and the voltage measuring terminal 2a, the distance between the voltage measuring terminal 2b and the voltage measuring terminal 2a is 28 mm. In this case, the sheet resistance value and the resistance measurement value by the 4-terminal method coincided.

  Here, an example of the positional relationship between the four sheet resistance measuring terminals has been shown. However, the present invention is not limited to this positional relationship, and other positional relationships, such as the current application terminal 1b and the voltage. There is no problem even if the distance between the measurement terminal 2b and the distance between the voltage measurement terminal 2a and the current application terminal 1a are different. Further, it is not always necessary that the four sheet resistance measuring terminals are arranged in a straight line.

  In other words, the sheet resistance measuring terminal according to the present invention may have any positional relationship as long as the resistance measurement value by the four-terminal method and the actual sheet resistance value are in agreement.

1a, 1b Current application terminals 2a, 2b Voltage measurement terminal 3 Terminal fixing member 4 Protective member 5 Connection line 6 Connection terminal

Claims (5)

  Measurement terminal used to measure the resistance of a thin film using the four-terminal method, and four measurements are made so that the measured voltage value divided by the current value is equal to the sheet resistance value of the thin film. Terminal for measurement, wherein the position of the terminal is fixed.   The measurement terminal according to claim 1, wherein the four measurement terminals for measurement are not equidistant.   The measurement terminal according to claim 1 or 2, wherein a material of the measurement terminal is a noble metal.   4. The measurement terminal according to claim 1, further comprising a spring mechanism in the measurement terminal.   A measurement lead using the measurement terminal according to claim 1.

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