JPH04315062A - Method for measuring resistance value of resistor - Google Patents

Abstract

PURPOSE:To obtain a method for accurately measuring the resistance value of the resistor (especially, the chip resistor) on a substrate and preventing the damage of a probe due to the pressing to an electrode and capable of easily corresponding to an extremely small resistor. CONSTITUTION:A power supply probe P1 to which the positive power line 21 and positive measuring wire 23 of a four-terminal resistance measueing device 20 are connected and a power supply probe Pn+1 to which the negative power line and negative measuring wire 24 of said measuring device are connected are respectively brought into contact with the electrodes a1, an+1 of both terminals R1-Rn connected on a substrate 1 in weries to allow a current to flow to the resistors R1-Rn. Measuring probes P2-Pn to which the negative and positive measuring wires 24, 23 of the measuring device 20 are alternately connected are brought into contact with electrodes a2-an other than the electrodes a1, an+1 to measure the voltages generated in the respective resistors R1-Rn and, from the current and respective voltages, the resistance values of the resistors R1-Rn are calculated. By this constitution, the resistance values of the resistors can be measued with high accuracy.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the resistance value of a resistor (particularly a chip resistor), which can accurately measure the resistance value of a resistor.

0002

2. Description of the Related Art Conventionally, the resistance value of a chip resistor, which is a resistor, is measured as shown in FIG. A four-terminal resistance measuring device 20 is usually used for the measurement. Measuring device 20
includes a number of power lines 21 corresponding to the number of resistors to be measured,
22 and measurement lines 23 and 24 are provided, and each power line and each measurement line can be switched by a relay. In FIG. 5, the power line 21 and the measurement line 23 are connected to the measurement probe 30.
A power line 22 and a measurement line 24 are connected to a measurement probe 31 .

[0003] Measurement probes 30 and 31 are then brought into contact with electrodes (conductors) 12 and 13 of a resistor 11 formed on, for example, a ceramic substrate 10, respectively. Similarly, the measurement probe is also brought into contact with all the resistors in the row parallel to the resistor 11. The resistance value is measured for each resistor by sequentially switching the relays. When the measurement of all parallel resistors is completed, the adjacent parallel resistors are also measured in the same manner.

As described above, in the conventional measurement method, as shown in the figure, each parallel resistor to be measured is performed for each parallel resistor that is not electrically connected by the electrode.

[0005]

However, since the electrodes 12 and 13 between each resistor 11 are generally very small,
In conventional measurement methods, it is not possible to provide a probe for each terminal of the measuring instrument 20. That is, as shown in FIG. 5, the measurement probes 30 and 31 each share a power line and a measurement line, and a power supply probe and a measurement probe are connected to each of the power line and measurement line to form one It cannot be brought into contact with the electrode. Therefore, the resistance of the power lines 21, 22 and the measurement lines 23, 24 can be ignored in the measurement circuit, but the contact resistance between the measurement probes 30, 31 and the electrodes 12, 13 cannot be ignored, and the resistance value of the resistor 11 cannot be ignored. Cannot measure accurately.

[0006] Also, the measurement probes 30 and 31 and the electrode 12
, 13 can be reduced by strongly pressing the measurement probe against the electrode, but the tip of the measurement probe tends to wear out or is often deformed. Furthermore, when pressing the measuring probe against the electrode with strong force, it is impossible to use a very thin probe that is particularly compatible with very small chip resistors.

[0007] Accordingly, an object of the present invention is to provide a method for accurately measuring the resistance value of a resistor (particularly a chip resistor) on a substrate. Another object of the present invention is to provide a measurement method that prevents damage to the probe due to pressing against the electrode and that can be easily applied to extremely small resistors.

[0008]

[Means for Solving the Problems] A method for measuring the resistance value of a resistor according to the present invention to achieve the above-mentioned object includes a method for measuring the resistance value of a resistor of a large number of resistors connected in series in each column. A power supply probe connected to a 4-terminal resistance measuring device is brought into contact with each of the electrodes, and a current is passed through all the resistors between the power supply probes. The method is characterized in that a measuring probe connected to a four-terminal resistance measuring device is brought into contact with the resistor, the voltage generated in each resistor is measured, and the resistance value of each resistor is calculated from the current and each voltage.

The measuring method of the present invention uses a four-terminal resistance measuring device, and a current is passed through all the resistors in the row from the electrodes of the resistors located at both ends of a row of resistors connected in series. The voltage of each resistor is measured, and the resistance value of each resistor is calculated based on the current value and each voltage value. In this measurement method, as will be seen later, it is preferable to press the power supply probe for flowing current against the electrode relatively strongly to ensure contact with the electrode, but the measurement probe for measuring voltage is It only needs to be lightly pressed against the electrode, and the contact resistance between the measurement probe and the electrode can be ignored. Moreover, the number of probes used for measurement (sum of power supply and measurement probes) is one more than the number of resistors in one row to be measured, so even in the case of small resistors, there are only 4 terminals. The configuration of the resistance measuring device can be simplified.

0010

EXAMPLES The method for measuring the resistance value of a resistor according to the present invention will be explained below based on examples. FIG. 1 shows a measurement method for chip resistors. This chip resistor includes, for example, a ceramic substrate 1, a resistor 2 formed on the substrate 1, and electrodes 3 and 4 that connect the resistor 2 in series in each column.

As an example of measurement, in order to measure the resistance values of n resistors connected in series, first the power connected to the positive power line 21 and positive measurement line 23 of the four-terminal resistance measuring device 20 is measured. Supply probe P1 and power supply probe Pn+1 connected to negative power line 22 and negative measurement line 24
are pressed against the electrodes a1 and an+1 of the resistors R1 and Rn located at both ends of the column, respectively. At this time, it is preferable to bring the probe into strong contact with the electrode so that the contact resistance between the two is sufficiently low. As a result, a constant current flows through all the resistors R1 to Rn in the column.

Next, power supply probes P1 and Pn+
Measurement probes P2 to Pn are brought into contact with all the electrodes a2 to an (no reference numerals are given in the figure) other than the electrodes a1 and an+1 which are in contact with electrodes A1 and an+1. Measurement probe P2
has a negative measuring line 24 on the measuring probe P3, a positive measuring line 23 on the measuring probe P3, and a negative measuring line 2 on the measuring probe P4.
4, a positive measuring line 23 is alternately connected to the measuring probe P5, and a negative measuring line 24 and a positive measuring line 23 are alternately connected to the measuring probes P2 to Pn. As a result, the positive measurement line 23 and the negative measurement line 24 are connected to each resistor R1 to Rn, and the preparation for measuring the resistance values of all the resistors R1 to Rn is completed. .

[0013] Here, by sequentially switching each relay of the measuring device 20, the voltage generated in each resistor R1 to Rn can be found, so the constant current and the voltage of each resistor R1 to Rn can be applied to Ohm's law. Then, the resistors R1 to Rn
Find the resistance value. Note that each resistance value is displayed on the measuring device 20, and it goes without saying that the measuring device 20 also calculates each resistance value. Through this measurement, the resistance values of the resistors R1 to Rn in the row through which current was passed can be determined. The resistance values of all the resistors on the substrate 1 can be known by moving the probe to the resistors in other rows and measuring them in the same way.

The measurement principle of the four-terminal resistance measuring device used in the measuring method of the present invention will now be described. A four-terminal resistance measuring device has a basic configuration as shown in FIG. The measuring device includes a constant current power source 50 and a voltmeter 51, and a power line from the power source 50 and a measurement line from the voltmeter 51 are connected to a resistor R in parallel. As a result, a current flows through the resistor R to be measured, and a voltage is applied to the resistor R to be measured.

Since the current IV flowing from the voltmeter 51 can be ignored compared to the current IM from the power source 50, that is, it can be considered that IV≈0, the actual current I flowing through the resistor R becomes I≈IM. Further, the voltage drop due to the resistance of the measurement line related to the voltmeter 51 and the contact resistances r3 and r4 of the connecting portion is IV (r3 + r4)≈0. For this reason,
Even if the values of the resistors r3 and r4 change, the voltage EM applied to the resistor R by the voltmeter 51 does not change, and can be considered as EM≈E (E is the actual voltage applied to the resistor R). Therefore, the value RM of the resistance R displayed by the resistance meter circuit 52 is RM=EM/IM=E/I=R
This is the reason.

In the measurement method of the present invention, the voltage drop due to the resistances r3 and r4 related to the voltmeter 51 is 0 based on the above measurement principle.
This takes advantage of the fact that it is equal to In other words, even if the contact resistance between the measurement probe and the electrode becomes large by lightly pressing the measurement probe related to the voltmeter 51 against the electrode, or the contact resistance changes depending on the degree to which the measurement probe is pressed against the electrode. However, it can always be considered that EM≒E. As a result, even if a probe is provided for each of the four terminals of a 4-terminal resistance measuring device, accurate resistance measurements can be made as long as the contact resistance is sufficiently low, such as by firmly pressing the power supply probe against the electrode. This is the reason.

FIG. 3 shows a circuit configuration of the measuring method of the present invention using a four-terminal resistance measuring device configured as shown in FIG. This measurement circuit is for five resistors R1 to R5. The current from the constant current power supply 60 flows through the power supply probe 62 to the resistors R1 to R5 connected in series, and the voltage of each resistor R1 to R5 is measured by the measurement probe 63.
The resistance value of each resistor R1 to R5 is calculated from this by the voltmeter 61. In this measurement circuit, if the contact resistance of the power supply probe 62 is made sufficiently low as described above, highly accurate measurement can be performed without depending on the contact resistance of the measurement probe 63. Moreover,
As is clear from FIG. 3, the total number of probes used for measurement is the number of resistances to be measured plus one (6 probes, 5+1 in the figure).

On the other hand, in the circuit configuration of the conventional measurement method shown in FIG.
0, and the number of measurement probes (also serving as power supply probes) 73 is twice the number of resistances to be measured (in the figure, 4 x 2 = 8). Furthermore, the resistance of the power line from the power source 70 and the measurement line from the voltmeter 71 can be ignored;
The contact resistance of the measurement probe 73 cannot be ignored, resulting in poor measurement accuracy.

In FIG. 3, the power supply probe 62 (P1, Pn+1 in FIG. 1) is connected to the resistor R1 at both ends.
, R5 (R1, Rn in Fig. 1) also serves as the other measurement probe, but the remaining resistance R2
~R4 As in R4, an independent measurement probe may be used in addition to the power supply probe.

[0020]

Effects of the Invention: As explained above, the method for measuring the resistance value of a resistor according to the present invention involves passing a current through the entire series of resistors connected in series, measuring the voltage across each resistor, and comparing the current with the current. Since the resistance value of each resistor is calculated from the voltage, the following effects are achieved. (1) The resistance value of a resistor can be measured with high precision. (2) Since the contact resistance of the measurement probe can be ignored, the measurement probe only needs to be lightly pressed against the electrode. Therefore, an extremely thin measuring probe can be used, and even extremely small resistance objects can be handled. (3) Since the measurement probe may be lightly pressed against the electrode, wear and deformation of the measurement probe is reduced, and the life of the measurement probe is extended. (4) The total number of probes for the resistor to be measured can be reduced by almost half compared to the conventional method. That is, the required number of probes is one more than the number of resistors.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the measurement method of the present invention.

FIG. 2 is a circuit diagram showing the configuration of a four-terminal resistance measuring device used in the measuring method of the present invention.

FIG. 3 is a circuit diagram of the measurement method of the present invention.

FIG. 4 is a circuit diagram of a conventional measurement method.

FIG. 5 is a diagram for explaining a conventional measurement method.

[Explanation of symbols]

1 Substrate 2, R1 to Rn Resistor 3, 4
, a1 ~an+1 electrode 20
4-terminal resistance measuring device 21, 2
2 Power lines 23, 24
Measurement line P1 ~ Pn+1
Probes (for power supply and measurement)

Claims (1)

[Claims] Claim 1: In a large number of resistors connected in series in each row, a power supply probe connected to a four-terminal resistance measuring device is brought into contact with the electrodes of each resistor located at both ends of one row, respectively, to supply power. A current is applied to all the resistors between the power supply probes, and a measurement probe connected to a 4-terminal resistance measuring device is brought into contact with at least the electrodes other than the electrodes that are in contact with the power supply probe, and the voltage generated in each resistor is measured. A method for measuring the resistance value of a resistor, characterized by measuring the resistance value of each resistor and calculating the resistance value of each resistor from the current and each voltage.