Resistance measurement method, device and system based on Kelvin connection

Abstract

The invention provides a Kelvin connection-based resistance measurement method, device and system. The method comprises the following steps of: forming Kelvin connection by adopting multiple paths of parameter measurement units (PMU) so as to test a to-be-measured resistor; determining the size of the first driving current; applying a first driving current to the to-be-tested resistor through the first path of PMU; measuring the voltage of the resistor to be measured through the second path of PMU and the third path of PMU; and obtaining the resistance value of the to-be-measured resistor according to the voltage of the to-be-measured resistor and the first driving current. According to the invention, the Kelvin test is carried out on the to-be-tested resistor by using the multi-path PMU of the automatic test equipment, so that the accuracy of resistance measurement is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor testing technology, and in particular to a resistance measurement method, device and system based on Kelvin connection. Background Art

[0002] Kelvin connection is a four-wire connection method, which is often used for accurate measurement of resistance impedance. Its main feature is that the measurement (Sense) and excitation (Force) are separated through a four-wire structure, eliminating the influence of the lead resistance and contact resistance of the measuring wire on the measurement result.

[0003] In the semiconductor testing industry, automatic test equipment ATE is often used to test semiconductor devices. ATE contains several PMU (Parametric Measurement Unit) resources. PMU is often used for DC parameter testing of IO pins of the device under test (DUT). It can drive current into the DUT to measure voltage or add voltage to the DUT to measure the generated current. However, PMU can only be stimulated first and then measured, and Kelvin connection cannot be achieved through one PMU.

[0004] How to use the PMU resources of ATE to form a Kelvin connection to test the impedance of the DUT is a problem worth solving. Summary of the invention

[0005] One of the purposes of the present invention is to provide a resistance measurement method, device and system based on Kelvin connection in order to solve the problems existing in the prior art.

[0006] The technical solution provided by the present invention is as follows:

[0007] A resistance measurement method based on Kelvin connection, comprising:

[0008] A multi-channel parameter measurement unit PMU is used to form a Kelvin connection to test the resistance to be measured;

[0009] Determining the magnitude of the first driving current;

[0010] Applying a first driving current to the resistor to be measured through a first PMU;

[0011] The voltage of the resistor to be measured is measured by the second PMU and the third PMU;

[0012] The resistance value of the resistor to be measured is obtained according to the voltage of the resistor to be measured and the first driving current.

[0013] In some embodiments, forming a Kelvin connection using a multi-channel parameter measurement unit PMU includes:

[0014] The first PMU and the fourth PMU are respectively connected to one end of the resistor to be measured through their own wires, and the second PMU and the third PMU are respectively connected to the other end of the resistor to be measured through their own wires; the first PMU, the fourth PMU and the resistor to be measured form a driving loop; the second PMU, the third PMU and the resistor to be measured form a measuring loop.

[0015] In some embodiments, applying a first driving current to the resistor to be measured through a first PMU includes:

[0016] A first driving current is applied to the first access point through the first PMU, a current close to 0 microamperes is applied to the second access point through the second PMU, a current close to 0 microamperes is applied to the third access point through the third PMU, and a voltage of 0 volts is applied to the fourth access point through the fourth PMU.

[0017] Measuring the voltage of the resistor to be measured by using the second PMU and the third PMU includes: measuring the voltage of the second access point by using the second PMU, and measuring the voltage of the third access point by using the third PMU; and obtaining the voltage of the resistor to be measured according to the voltage of the second access point and the voltage of the third access point.

[0018] In some embodiments, determining the magnitude of the first driving current includes:

[0019] Predetermine the real resistance value of the first resistor R1 connecting the first access point and one end of the resistor to be measured and the real resistance value of the fourth resistor R4 connecting the fourth access point and the other end of the resistor to be measured;

[0020] Applying a plurality of driving currents of different magnitudes to the first access point through the first PMU, and measuring the voltages of the first access point, the second access point, and the third access point corresponding to each driving current;

[0021] According to the voltages of the first access point, the second access point, and the third access point, a measurement value of the first resistor R1 and a measurement value of the fourth resistor R4 are obtained; a measurement error of the first resistor is obtained according to the measurement value of the first resistor R1 and the actual resistance value, and a measurement error of the fourth resistor is obtained according to the measurement value of the fourth resistor R1 and the actual resistance value; the measurement errors of the first resistor and the fourth resistor constitute a set of resistance measurement errors corresponding to the driving current;

[0022] A group of corresponding driving currents with smaller resistance measurement errors are selected from all resistance measurement errors as the magnitude of the first driving current.

[0023] In some embodiments, obtaining a measured value of the first resistor R1 and a measured value of the fourth resistor R4 according to the voltages of the first access point, the second access point, and the third access point includes:

[0024] The difference between the voltage at the second access point and the voltage at the first access point is divided by the driving current to obtain a measured value of the first resistor R1;

[0025] The voltage of the third access point is divided by the driving current to obtain a measured value of the fourth resistor R4.

[0026] The present invention also provides a resistance measuring device based on Kelvin connection, comprising:

[0027] A Kelvin connection building module is used to form a Kelvin connection using a multi-channel parameter measurement unit PMU to test a resistance to be measured;

[0028] A current determination module, used to determine the magnitude of the first driving current;

[0029] An excitation module, used for applying a first driving current to the resistor to be measured through a first PMU;

[0030] A measuring module, used for measuring the voltage of the resistor to be measured through the second PMU and the third PMU;

[0031] The calculation module is used to obtain the resistance value of the resistor to be measured according to the voltage of the resistor to be measured and the first driving current.

[0032] In some embodiments, the first PMU and the fourth PMU are respectively connected to one end of the resistor to be measured through their own wires, and the second PMU and the third PMU are respectively connected to the other end of the resistor to be measured through their own wires; the first PMU, the fourth PMU, and the resistor to be measured form a driving loop; the second PMU, the third PMU, and the resistor to be measured form a measuring loop.

[0033] In some embodiments, the excitation module is further used to apply a first driving current at the first access point through the first PMU, apply a current close to 0 microamperes at the second access point through the second PMU, apply a current close to 0 microamperes at the third access point through the third PMU, and apply a voltage of 0 volts at the fourth access point through the fourth PMU;

[0034] The measuring module is further used to measure the voltage of the second access point through the second PMU and the voltage of the third access point through the third PMU; and obtain the voltage of the resistor to be measured according to the voltage of the second access point and the voltage of the third access point.

[0035] In some embodiments, the current determination module includes:

[0036] a resistance determination unit, used to predetermine a real resistance value of a first resistor R1 connecting the first access point and one end of the resistor to be measured and a real resistance value of a fourth resistor R4 connecting the fourth access point and the other end of the resistor to be measured;

[0037] A voltage testing unit, used for applying a plurality of driving currents of different magnitudes to the first access point through the first PMU, and measuring the voltages of the first access point, the second access point, and the third access point corresponding to each driving current;

[0038] an error calculation unit, configured to obtain a measurement value of a first resistor R1 and a measurement value of a fourth resistor R4 according to voltages at the first access point, the second access point, and the third access point; obtain a measurement error of the first resistor according to the measurement value of the first resistor R1 and a true resistance value, and obtain a measurement error of the fourth resistor according to the measurement value of the fourth resistor R1 and a true resistance value; the measurement errors of the first resistor and the fourth resistor constitute a set of resistance measurement errors corresponding to the driving current;

[0039] The current determining unit is used to select a group of corresponding driving currents with small resistance measurement errors from all resistance measurement errors as the magnitude of the first driving current.

[0040] The present invention also provides a resistance measurement system, comprising:

[0041] Automatic test equipment for providing several parameter measurement units PMU;

[0042] The resistance measuring device based on Kelvin connection of any of the aforementioned embodiments utilizes a multi-channel PMU to perform a Kelvin test on the resistance to be measured.

[0043] The resistance measurement method, device and system based on Kelvin connection provided by the present invention can at least bring the following beneficial effects:

[0044] 1. The present invention utilizes the multi-channel PMU resources of the ATE equipment to form a Kelvin connection, adopts the Kelvin test method to measure the resistance to be measured, eliminates the influence of the lead resistance and the contact resistance, and improves the accuracy of the resistance measurement.

[0045] 2. The present invention can further improve the measurement accuracy of the resistance value of the resistor to be measured by obtaining the measurement errors of (lead resistance + contact resistance) under different driving currents in the driving circuit, and then selecting a suitable driving current size as the first driving current based on these measurement errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The following will explain the preferred implementation mode in a clear and understandable manner with reference to the accompanying drawings, and further explain the above-mentioned characteristics, technical features, advantages and implementation methods of a resistance measurement method, device and system based on Kelvin connection.

[0047] Figure 1 is a flow chart of an embodiment of a resistance measurement method based on Kelvin connection of the present invention;

[0048] Figure 2It is a structural schematic diagram of an embodiment of a resistance measuring device based on Kelvin connection of the present invention;

[0049] Figure 3 is a structural schematic diagram of an embodiment of a resistance measurement system of the present invention;

[0050] Figure 4 yes Figure 1 A schematic diagram of a Kelvin connection structure;

[0051] Figure 5 It is a circuit schematic diagram for testing resistors using Kelvin connections. DETAILED DESCRIPTION

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0053] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0054] One embodiment of the present invention, as Figure 1 As shown, a resistance measurement method based on Kelvin connection includes:

[0055] In step S100 , a multi-channel parameter measurement unit PMU is used to form a Kelvin connection to test the resistance to be measured.

[0056] Among them, the first PMU and the fourth PMU are respectively connected to one end of the resistor to be measured through their own wires, and the second PMU and the third PMU are respectively connected to the other end of the resistor to be measured through their own wires; the first PMU, the fourth PMU and the resistor to be measured form a driving loop; the second PMU, the third PMU and the resistor to be measured form a measuring loop.

[0057] Specifically, the Kelvin connection is also called a four-wire connection, such as Figure 5As shown in the figure, there are four lines, namely High Force (HF), Low Force (LF), High Sense (HS) and Low Sense (LS). HF and LF are also called excitation lines, which are used to transmit current; HS and LS are also called detection lines, which are used to detect voltage. The two are strictly separated and each constitutes an independent circuit.

[0058] Rt is the resistance to be measured. r1~r4 represent the sum of the lead resistance on each line and the contact resistance between the probe and the test point. Since the current flowing through the test line is very small, approximately 0, and the voltage drop on r3 and r4 is also zero, the voltmeter can accurately measure the voltage value across Rt. The voltage value across Rt is divided by the excitation current i to obtain the resistance value of Rt.

[0059] The PMU measurement unit is a device used to perform voltage and current measurements during semiconductor testing and verification. It can provide and measure the voltage and current of the device under test (DUT). The resistance under test can be, but is not limited to, the resistance between two pins of the device under test DUT, or an independent resistance device.

[0060] Since a single-channel PMU cannot realize Kelvin connection, this embodiment uses multiple-channel PMU to realize Kelvin connection. Figure 4 In an example shown, the first PMU is connected to the pin 1 of the device under test DUT via the first resistor R1 at the first access point IO1, the second PMU is connected to the pin 1 of the DUT via the second resistor R2 at the second access point IO2, the third PMU is connected to the pin 2 of the DUT via the third resistor R3 at the third access point IO3, and the fourth PMU is connected to the pin 2 of the DUT via the fourth resistor R4 at the fourth access point IO4. Figure 4 The Kelvin connection structure shown is used to measure the resistance between pin 1 and pin 2 of the DUT, namely Rtest. The first PMU forms a driving loop through R1, Rtest, R4 and the fourth PMU. The second PMU forms a measurement loop through R2, Rtest, R3 and the third PMU. R1 to R4 correspond to the sum of the lead resistance and contact resistance between each PMU and the pin of the DUT.

[0061] Step S200 determines the magnitude of the first driving current.

[0062] Step S300 applies a first driving current to the resistor to be tested, including: applying the first driving current at the first access point through the first PMU, applying a 0 volt voltage at the fourth access point through the fourth PMU, applying a current close to 0 microamperes at the second access point through the second PMU; and applying a current close to 0 microamperes at the third access point through the third PMU.

[0063] like Figure 4As shown, a first driving current I1 is applied to the first access point IO1, a current of 0 microampere is applied to the second access point IO2, a current of 0 microampere is applied to the third access point IO3, and a voltage of 0 volt is applied to the fourth access point IO4.

[0064] Step S400 measures the voltage of the resistor to be measured, including: measuring the voltage of the second access point through the second PMU, measuring the voltage of the third access point through the third PMU; and obtaining the voltage of the resistor to be measured according to the voltage of the second access point and the voltage of the third access point.

[0065] Step S500 obtains the resistance value of the resistor to be measured according to the voltage of the resistor to be measured and the first driving current.

[0066] like Figure 4 As shown in the figure, since IO2 is kept at 0uA, it is equivalent to no current passing through R2, so the influence of R2 can be avoided, and the voltage U2 measured at the second access point IO2 represents the potential Va of pin 1. Similarly, the voltage U3 measured at the third access point IO3 represents the potential Vb of pin 2. The voltage on Rtest is obtained based on U3 and U2, and then divided by the applied current I1 to obtain the resistance Rtest that is not affected by the contact resistance, that is, Rtest = (U2-U3) / I1.

[0067] In this embodiment, the multi-channel PMU resources of the ATE equipment are used to form a Kelvin connection, and the Kelvin test method is used to measure the resistance to be measured, thereby eliminating the influence of the lead resistance and the contact resistance and improving the accuracy of the resistance measurement.

[0068] In one embodiment, step S200 includes:

[0069] Step S210 predetermines a real resistance value of a first resistor R1 connecting the first access point and one end of the resistor to be measured and a real resistance value of a fourth resistor R4 connecting the fourth access point and the other end of the resistor to be measured;

[0070] Step S220: applying a plurality of driving currents of different magnitudes to the first access point through the first PMU, and measuring the voltages of the first access point, the second access point, and the third access point corresponding to each driving current;

[0071] Step S230: obtaining a measurement value of the first resistor R1 and a measurement value of the fourth resistor R4 according to the voltages of the first access point, the second access point, and the third access point; obtaining a measurement error of the first resistor according to the measurement value of the first resistor R1 and the actual resistance value, and obtaining a measurement error of the fourth resistor according to the measurement value of the fourth resistor R1 and the actual resistance value; the measurement errors of the first resistor and the fourth resistor constitute a set of resistance measurement errors corresponding to the driving current;

[0072] Step S240 selects a group of corresponding driving currents with smaller resistance measurement errors from all resistance measurement errors as the magnitude of the first driving current.

[0073] As described in the previous embodiment, Rmeasure = (U2-U3) / I1. Figure 4 As shown, U2=Va=U1-R1*I1, U3=Vb=R4*I1, so Rmeasure=(Va-Vb) / I1=(U1-R1*I1-R4*I1) / I1=U1 / I1-R1-R4, the measurement accuracy of Rmeasure can be converted into the measurement accuracy of (R1+R4).

[0074] right Figure 4 The circuit model shown was used to perform the following experiments:

[0075] 1) Determine the actual set values ​​of R1 and R4 in advance, such as R1 = 104.5Ω, R4 = 12.3Ω.

[0076] 2) Set different values ​​for I1 and measure the voltages of U1 to U3 respectively.

[0077] 3) Calculate the measured resistance values ​​of R1 and R4, R1 measured = (U1-U2) / I1, R4 measured = U3 / I1.

[0078] 4) Calculate the measurement error of R1 and R4.

[0079] 5) Get the results shown in the following table:

[0080]

[0081] Usually the contact resistance is between 0-100Ω. It can be seen from the experimental data that within this range, when the drawn current is greater than 2mA, the larger the current, the greater the measurement error of the resistance value. The best drawn current is between 100uA-1mA, and the test accuracy is the highest when the drawn current is 1mA. According to the above experimental data, it is more appropriate to select 1mA as the first drive current I1.

[0082] For different ATE testers, when drawing smaller currents, the errors caused by different gears and current magnitudes are also different. In actual testing, it is necessary to select the driving current magnitude in accordance with the accuracy and gear of the tester used. Selecting the appropriate current magnitude can improve the measurement accuracy of (lead resistance + contact resistance), thereby improving the measurement accuracy of R measurement.

[0083] In this embodiment, by obtaining the measurement errors of (R1+R4) under different driving currents in the driving circuit, and then selecting a suitable driving current as the first driving current according to these measurement errors, the measurement accuracy of the resistance value of the resistor to be measured can be further improved.

[0084] In one embodiment, step S230 obtains the measured value of the first resistor R1 and the measured value of the fourth resistor R4 according to the voltages of the first access point, the second access point, and the third access point, including:

[0085] Step S231: Divide the difference between the voltage at the second access point and the voltage at the first access point by the driving current to obtain a measured value of the first resistor R1;

[0086] Step S232 divides the voltage of the third access point by the driving current to obtain a measured value of the fourth resistor R4.

[0087] One embodiment of the present invention, as Figure 2 As shown, a resistance measuring device 100 based on Kelvin connection includes:

[0088] The Kelvin connection building module 110 is used to form a Kelvin connection using a multi-channel parameter measurement unit PMU to test the resistor to be measured, wherein the first PMU and the fourth PMU are respectively connected to one end of the resistor to be measured through their own wires, and the second PMU and the third PMU are respectively connected to the other end of the resistor to be measured through their own wires; the first PMU, the fourth PMU and the resistor to be measured form a driving loop; the second PMU, the third PMU and the resistor to be measured form a measuring loop.

[0089] The current determination module 120 is used to determine the magnitude of the first driving current.

[0090] The excitation module 130 is used to apply a first driving current to the resistor to be measured through the first PMU, including: applying the first driving current at the first access point through the first PMU, applying a 0 volt voltage at the fourth access point through the fourth PMU, applying a current close to 0 microamperes at the second access point through the second PMU; and applying a current close to 0 microamperes at the third access point through the third PMU.

[0091] The measuring module 140 is used to measure the voltage of the resistor to be measured, including: measuring the voltage of the second access point through the second PMU, measuring the voltage of the third access point through the third PMU; and obtaining the voltage of the resistor to be measured according to the voltage of the second access point and the voltage of the third access point.

[0092] The calculation module 150 is used to obtain the resistance value of the resistor to be measured according to the voltage of the resistor to be measured and the first driving current.

[0093] In this embodiment, the multi-channel PMU resources of the ATE equipment are used to form a Kelvin connection, and the Kelvin test method is used to measure the resistance to be measured, thereby eliminating the influence of the lead resistance and the contact resistance and improving the accuracy of the resistance measurement.

[0094] In one embodiment, the current determination module 120 includes:

[0095] The resistance determination unit is used to predetermine the real resistance value of the first resistor R1 connecting the first access point and one end of the resistor to be measured and the real resistance value of the fourth resistor R4 connecting the fourth access point and the other end of the resistor to be measured.

[0096] The voltage testing unit is used to apply a plurality of driving currents of different magnitudes to the first access point through the first PMU, and measure the voltages of the first access point, the second access point and the third access point corresponding to each driving current.

[0097] The error calculation unit is used to obtain the measured value of the first resistor R1 and the measured value of the fourth resistor R4 according to the voltages of the first access point, the second access point and the third access point; obtain the measurement error of the first resistor according to the measured value of the first resistor R1 and the actual resistance value, and obtain the measurement error of the fourth resistor according to the measured value of the fourth resistor R1 and the actual resistance value; the measurement errors of the first resistor and the fourth resistor constitute a group of resistance measurement errors corresponding to the driving current.

[0098] The current determining unit is used to select a group of corresponding driving currents with small resistance measurement errors from all resistance measurement errors as the magnitude of the first driving current.

[0099] In this embodiment, by obtaining the measurement errors of (R1+R4) under different driving currents in the driving circuit, and then selecting a suitable driving current as the first driving current according to these measurement errors, the measurement accuracy of the resistance value of the resistor to be measured can be further improved.

[0100] In one embodiment, the error calculation unit is further configured to divide the difference between the voltage at the second access point and the voltage at the first access point by the driving current to obtain the measurement value of the first resistor R1; and divide the voltage at the third access point by the driving current to obtain the measurement value of the fourth resistor R4.

[0101] It should be noted that the embodiment of the resistance measuring device based on Kelvin connection provided by the present invention and the embodiment of the resistance measuring method based on Kelvin connection provided above are based on the same inventive concept and can achieve the same technical effect. Therefore, other specific contents of the embodiment of the resistance measuring device based on Kelvin connection can refer to the contents of the embodiment of the resistance measuring method based on Kelvin connection described above.

[0102] One embodiment of the present invention, as Figure 3 As shown, a resistance measurement system comprises:

[0103] The automatic test equipment 200 is used to provide a number of parameter measurement units PMU;

[0104] The resistance measuring device 100 based on Kelvin connection described in any of the above embodiments utilizes a multi-channel PMU to perform a Kelvin test on the resistance to be measured.

[0105] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A resistance measurement method based on Kelvin connection, characterized in that: include: A multi-channel parameter measurement unit PMU is used to form a Kelvin connection to test the resistance to be measured; Determining the magnitude of the first driving current; Applying the first driving current to the resistor to be measured through a first PMU; Measuring the voltage of the resistor to be measured by the second PMU and the third PMU; The resistance value of the resistor to be measured is obtained according to the voltage of the resistor to be measured and the first driving current.

2. The resistance measuring method according to claim 1, characterized in that: The method of using a multi-channel parameter measurement unit PMU to form a Kelvin connection includes: The first PMU and the fourth PMU are respectively connected to one end of the resistor to be measured through their own wires, and the second PMU and the third PMU are respectively connected to the other end of the resistor to be measured through their own wires; the first PMU, the fourth PMU and the resistor to be measured form a driving loop; the second PMU, the third PMU and the resistor to be measured form a measuring loop.

3. The resistance measuring method according to claim 2, characterized in that: Applying the first driving current to the resistor to be measured through the first PMU includes: Applying the first driving current at the first access point through the first PMU, applying a current close to 0 microamperes at the second access point through the second PMU, applying a current close to 0 microamperes at the third access point through the third PMU, and applying a voltage of 0 volts at the fourth access point through the fourth PMU; Measuring the voltage of the resistor to be measured by using the second PMU and the third PMU includes: measuring the voltage of the second access point by using the second PMU, and measuring the voltage of the third access point by using the third PMU; and obtaining the voltage of the resistor to be measured according to the voltage of the second access point and the voltage of the third access point.

4. The resistance measuring method according to claim 2, characterized in that: Determining the magnitude of the first driving current includes: Predetermining a real resistance value of a first resistor R1 connecting the first access point and one end of the resistor to be measured and a real resistance value of a fourth resistor R4 connecting the fourth access point and the other end of the resistor to be measured; Applying a plurality of driving currents of different magnitudes to the first access point through the first PMU, and measuring the voltages of the first access point, the second access point, and the third access point corresponding to each driving current; According to the voltages of the first access point, the second access point, and the third access point, a measurement value of the first resistor R1 and a measurement value of the fourth resistor R4 are obtained; a measurement error of the first resistor is obtained according to the measurement value of the first resistor R1 and a true resistance value, and a measurement error of the fourth resistor is obtained according to the measurement value of the fourth resistor R1 and a true resistance value; the measurement errors of the first resistor and the fourth resistor constitute a set of resistance measurement errors corresponding to the driving current; A group of corresponding driving currents with smaller resistance measurement errors are selected from all resistance measurement errors as the magnitude of the first driving current.

5. The resistance measuring method according to claim 4, characterized in that: Obtaining a measured value of the first resistor R1 and a measured value of the fourth resistor R4 according to the voltages of the first access point, the second access point, and the third access point, including: The difference between the voltage at the second access point and the voltage at the first access point is divided by the driving current to obtain a measured value of the first resistor R1; The voltage of the third access point is divided by the driving current to obtain a measured value of the fourth resistor R4.

6. A resistance measuring device based on Kelvin connection, characterized in that: include: A Kelvin connection building module is used to form a Kelvin connection using a multi-channel parameter measurement unit PMU to test a resistance to be measured; A current determination module, used to determine the magnitude of the first driving current; An excitation module, used for applying the first driving current to the resistor to be measured through a first PMU; A measuring module, used for measuring the voltage of the resistor to be measured through a second PMU and a third PMU; A calculation module is used to obtain the resistance value of the resistor to be measured according to the voltage of the resistor to be measured and the first driving current.

7. The resistance measuring device according to claim 6, characterized in that: The first PMU and the fourth PMU are respectively connected to one end of the resistor to be measured through their own wires, and the second PMU and the third PMU are respectively connected to the other end of the resistor to be measured through their own wires; the first PMU, the fourth PMU and the resistor to be measured form a driving loop; the second PMU, the third PMU and the resistor to be measured form a measuring loop.

8. The resistance measuring device according to claim 7, characterized in that: The excitation module is further configured to apply the first driving current at the first access point through the first PMU, apply a current close to 0 microamperes at the second access point through the second PMU, apply a current close to 0 microamperes at the third access point through the third PMU, and apply a voltage of 0 volts at the fourth access point through the fourth PMU; The measurement module is further used to measure the voltage of the second access point through the second PMU, and measure the voltage of the third access point through the third PMU; and obtain the voltage of the resistor to be measured according to the voltage of the second access point and the voltage of the third access point.

9. The resistance measuring device according to claim 7, characterized in that: The current determination module comprises: a resistance determination unit, configured to predetermine a real resistance value of a first resistor R1 connecting the first access point and one end of the resistor to be measured and a real resistance value of a fourth resistor R4 connecting the fourth access point and the other end of the resistor to be measured; a voltage testing unit, configured to apply a plurality of driving currents of different magnitudes to the first access point through the first PMU, and measure the voltages of the first access point, the second access point, and the third access point corresponding to each driving current; an error calculation unit, configured to obtain a measurement value of the first resistor R1 and a measurement value of the fourth resistor R4 according to the voltages of the first access point, the second access point, and the third access point; obtain a measurement error of the first resistor according to the measurement value of the first resistor R1 and a true resistance value, and obtain a measurement error of the fourth resistor according to the measurement value of the fourth resistor R1 and a true resistance value; the measurement errors of the first resistor and the fourth resistor constitute a set of resistance measurement errors corresponding to the driving current; The current determining unit is used to select a group of corresponding driving currents with smaller resistance measurement errors from all resistance measurement errors as the magnitude of the first driving current.

10. A resistance measurement system, characterized in that: include: Automatic test equipment for providing several parameter measurement units PMU; The resistance measuring device based on Kelvin connection described in any one of claims 6 to 9 utilizes a multi-channel PMU to perform a Kelvin test on the resistance to be measured.

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