CN115932401A

CN115932401A - Kelvin-based test circuit, test method and test device

Info

Publication number: CN115932401A
Application number: CN202211408213.9A
Authority: CN
Inventors: 王华杰; 李晨阳; 姚健
Original assignee: Huafeng Test & Control Technology Tianjin Co ltd; Beijing Huafeng Test & Control Technology Co ltd
Current assignee: Huafeng Test & Control Technology Tianjin Co ltd; Beijing Huafeng Test & Control Technology Co ltd
Priority date: 2022-11-10
Filing date: 2022-11-10
Publication date: 2023-04-07

Abstract

The application relates to a Kelvin-based test circuit, a test method and a test device, closed resistances of a high-end measurement circuit and a low-end measurement circuit can be obtained through the circuit, and then when the high-end measurement circuit is formed in the subsequent process of testing a device to be tested, the interference of the closed resistance of the high-end measurement circuit on the device to be tested can be eliminated through the obtained combined resistance value of one end of the device to be tested and the high-end measurement circuit, and then the contact resistance of one end of the device to be tested is obtained through a difference value elimination method, so that the contact resistance measurement is more accurate; similarly, when a low-end measuring circuit is formed subsequently to test the device under test, the interference of the closed resistor of the low-end measuring circuit on the device under test can be eliminated by the obtained combined resistance value of one end of the device under test and the low-end measuring circuit and the difference elimination method, so that the contact resistance at one end of the device under test is obtained, and the contact resistance measurement is more accurate.

Description

Kelvin-based test circuit, test method and test device

Technical Field

The present disclosure relates to the field of circuit testing technologies, and in particular, to a kelvin-based test circuit, a kelvin-based test method, and a kelvin-based test apparatus.

Background

In integrated circuit testing, a voltage current source (hereinafter referred to as a VI source) is required for signal excitation and voltage current measurement of a Device Under Test (hereinafter referred to as a DUT).

In order to improve the accuracy of output voltage and test voltage, the conventional VI source adopts a four-wire Kelvin (Kelvin) connection mode, which is a High-end current line (Force High), a High-end voltage line (Sense High), a Low-end current line (Force Low), and a Low-end voltage line (Sense Low). Wherein current is output (or input) from a High side current line (Force High) and back-flowed (or output) from a Low side current line (Force Low). Wherein, R1 and R2 are equivalent resistances generated in the transmission link of the high-end current line and the low-end current line respectively, and because the current flows through R1 and R2, a certain voltage drop can be generated in the current transmission link, which affects the subsequent measurement, and the resistance value of the contact resistance of the device to be measured can not be accurately measured.

Disclosure of Invention

The application provides a Kelvin-based test circuit, a test method and a test device, which are used for solving the problem that the resistance value of a contact resistor of a tested device cannot be accurately measured in the related technology.

In a first aspect, the present application provides a kelvin-based test circuit comprising: the current source, the voltmeter, the high-end current line, the low-end current line, the high-end voltage line and the low-end voltage line; one end of each of the high-end current line and the low-end current line is connected with a current source, the other end of each of the high-end current line and the low-end current line is used for being connected with a first connector, and the other end of each of the low-end current line and the high-end current line is used for being connected with a second connector; one end of the high-end voltage line and one end of the low-end voltage line are connected with the voltmeter, the other end of the high-end voltage line is used for being connected with a third connector, the other end of the low-end voltage line is used for being connected with a fourth connector, one end of the first connector and one end of the third connector are in short circuit, one end of the second connector and one end of the fourth connector are in short circuit, one end of the first connector and one end of the third connector in short circuit are used for being connected into one end of a tested device, and one end of the second connector and one end of the fourth connector in short circuit are connected into the other end of the tested device; high-end electric current line with be provided with first connecting circuit between the high-end voltage line, low-end electric current line with be provided with the second connecting circuit between the low side voltage line and connect, high-end voltage line with be provided with the third connecting circuit between the low side voltage line, all be provided with on every connecting circuit and be used for controlling every connecting circuit switch-on or the switch that ends, the high-end electric current line the low side electric current line high-end voltage line and the low side voltage line all is provided with the switch.

In some examples, the high-side current line is provided with a first connection point, the high-side voltage line is provided with a second connection point and a third connection point, the second connection point is close to the voltmeter, the third connection point is far away from the voltmeter, the low-side voltage line is provided with a fourth connection point and a fifth connection point, the fourth connection point is close to the voltmeter, and the fifth connection point is far away from the voltmeter; a sixth connection point is arranged on the low-side current wire; one end of the first connecting circuit is connected with the first connecting point, and the other end of the first connecting circuit is connected with the second connecting point; one end of the second connection circuit is connected with the fourth connection point, and the other end of the second connection circuit is connected with the sixth connection point; one end of the third connection circuit is connected to the third connection point, and the other end of the third connection circuit is connected to the fifth connection point.

In some examples, the switch in the kelvin-based test circuit is a relay; a first relay is arranged on one side, away from the current source and the first connecting point, of the high-end current line; the first connecting circuit is provided with a second relay; a third relay is arranged between the second connection point and the third connection point of the high-end voltage line; the third connecting circuit is provided with a fourth relay; a fifth relay is arranged between the fourth connection point and the fifth connection point of the low-side voltage line; the second connecting circuit is provided with a sixth relay; a seventh relay is arranged on one side, far away from the current source and the sixth connection point, of the low-end current line; an eighth relay is arranged on one side, far away from the second connection point and the third connection point, of the high-end voltage line; and a ninth relay is arranged on one side of the low-end voltage line, which is far away from the fourth connection point and the fifth connection point.

In some examples, the kelvin-based test circuit further comprises: a controller; the controller is used for controlling the first relay, the second relay, the fourth relay, the fifth relay, the sixth relay and the eighth relay to be closed to form a high-end measuring circuit; the controller is used for controlling the second relay, the third relay, the fourth relay, the sixth relay, the seventh relay and the ninth relay to be closed to form a low-end measuring circuit.

In some examples, the kelvin-based test circuit further comprises: a temperature detection circuit; the temperature detection circuit is used for detecting the ambient temperature of each relay in the Kelvin-based test circuit.

In a second aspect, the present application provides a method of testing, the method comprising: respectively testing the combined resistance values of two ends of the tested device and the high-end measuring circuit and the low-end measuring circuit through a Kelvin-based testing circuit; acquiring the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit in the Kelvin-based testing circuit; and correcting the combined resistance values at the two ends of the tested device based on the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit to obtain the contact resistance values at the two ends of the tested device.

In some examples, obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the kelvin-based test circuit includes: connecting one end, far away from a current source, of a high-end current line in the Kelvin-based test circuit with one end, far away from a voltmeter, of a high-end voltage line to form a high-end measurement circuit, and acquiring a closed resistance of the high-end measurement circuit; and connecting one end of a low-end current line in the Kelvin-based test circuit, which is far away from the current source, with one end of a low-end voltage line, which is far away from the voltmeter, to form the low-end measurement circuit, and acquiring the closed resistance of the low-end measurement circuit.

In some examples, prior to obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the kelvin-based test circuit, the method further comprises: connecting one end, far away from a current source, of a high-end current line in the Kelvin-based test circuit with one end, far away from a voltmeter, of a high-end voltage line to form a high-end measurement circuit, acquiring the temperature and the closing resistance of the high-end measurement circuit when the high-end measurement circuit is closed, and generating a corresponding relation between the temperature and the resistance corresponding to the high-end measurement circuit based on the temperature and the closing resistance when the high-end measurement circuit is closed; and connecting one end, far away from the current source, of the low-end current line in the Kelvin-based test circuit with one end, far away from the voltmeter, of the low-end voltage line to form the low-end measurement circuit, acquiring the temperature and the closing resistance of the low-end measurement circuit when the low-end measurement circuit is closed, and generating the corresponding relation between the temperature and the resistance corresponding to the low-end measurement circuit based on the temperature and the closing resistance when the low-end measurement circuit is closed.

In some examples, obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the kelvin-based test circuit includes: acquiring the test temperature of the high-end measurement circuit when the device under test is tested, and determining the corresponding closed resistance of the high-end measurement circuit when the device under test is tested based on the test temperature and the corresponding relationship between the temperature and the resistance corresponding to the high-end measurement circuit; and acquiring the test temperature of the low-end measuring circuit when the device under test is tested, and determining the corresponding closed resistance of the low-end measuring circuit when the device under test is tested based on the test temperature and the corresponding relation between the temperature and the resistance corresponding to the low-end measuring circuit.

In a third aspect, a test apparatus is provided, the test apparatus comprising: the test module is used for respectively testing the combined resistance values of the two ends of the tested device and the high-end measuring circuit and the low-end measuring circuit through a Kelvin-based test circuit; an acquisition module for acquiring a closed resistance of the high-end measurement circuit and a closed resistance of the low-end measurement circuit in the Kelvin-based test circuit; and the correction module is used for correcting the combined resistance values at the two ends of the tested device based on the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit to obtain the contact resistance values at the two ends of the tested device.

In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any of the embodiments of the first aspect.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

according to the Kelvin-based test circuit provided by the embodiment of the application, one end, far away from a current source, of a High-end current line is connected with one end, far away from a voltmeter, of a High-end voltage line, and through the matching of switches on the connecting circuits, the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, the High-end measurement circuit is further formed, and the resistance value of a closing resistor of the High-end measurement circuit can be obtained by closing the High-end measurement circuit at the moment; connecting one end of a Low-end current wire, which is far away from a current source, with one end of a Low-end voltage wire, which is far away from a voltmeter, and forming the Low-end measuring circuit through the matching of switches on each connecting circuit, the High-end current wire Force High, the Low-end current wire Force Low, the High-end voltage wire Sense High and the Low-end voltage wire Sense Low, wherein the Low-end measuring circuit is closed, the resistance value of a closed resistor of the Low-end measuring circuit can be obtained, the first connector is connected with the subsequent end of the High-end current wire, which is far away from the current source, and the third connector is connected with the subsequent end of the High-end current wire, the High-end voltage wire, which is far away from the voltmeter, and the first connector and the third connector are in short circuit connection, and one end of a tested device is connected at the same time, so that when the High-end measuring circuit tests the tested device, the combined resistance value of the tested device and the High-end measuring circuit can be obtained through the obtained, and then the interference of the closed resistor of the High-end measuring circuit is eliminated by using a difference value elimination method, so that the resistance value of the contact resistor at one end of the tested device is obtained, and the contact resistor is more accurate in measurement; similarly, when the low-end measuring circuit is used for testing the device to be tested, the combined resistance value of one end of the device to be tested and the low-end measuring circuit can be obtained, then the interference of the closed resistance of the low-end measuring circuit on the device to be tested is eliminated by using a difference elimination method, the resistance value of the contact resistor at one end of the device to be tested is obtained, and the contact resistor measurement is more accurate.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a basic diagram of a Kelvin-based test circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic basic flowchart of a testing method according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a basic structure for forming a high-side measurement circuit according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a basic process flow for forming a low-side measurement circuit according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a Force High and Sense High short circuit according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a Force Low and Sense Low short circuit according to an embodiment of the present disclosure;

fig. 7 is a basic schematic diagram of an equivalent resistance circuit of a High-end measurement circuit according to an embodiment of the present disclosure;

fig. 8 is a basic schematic diagram of an equivalent resistance circuit of a Low end measurement circuit according to an embodiment of the present disclosure;

FIG. 9 is a schematic diagram illustrating the contact resistance equivalence of a device under test of a High-side measurement circuit according to an embodiment of the present application;

FIG. 10 is a schematic diagram illustrating a contact resistance equivalence of a device under test of a Low-side measurement circuit according to an embodiment of the present disclosure;

FIG. 11 is a schematic diagram of a basic structure of a high-end measurement circuit formed when a temperature detection circuit is provided according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram of a basic flow chart for forming a low-end measurement circuit when a temperature detection circuit is provided according to an embodiment of the present application;

FIG. 13 is a basic schematic diagram of a Force High and Sense High short circuit when a temperature detection circuit is provided according to an embodiment of the present application;

FIG. 14 is a schematic diagram illustrating a Force Low and Sense Low short circuit when a temperature detection circuit is provided according to an embodiment of the present disclosure;

fig. 15 is a basic schematic diagram of an equivalent resistance circuit of a High-side measurement circuit provided with a temperature detection circuit according to an embodiment of the present application;

fig. 16 is a basic schematic diagram of an equivalent resistance circuit of a Low end measurement circuit provided with a temperature detection circuit according to an embodiment of the present application;

FIG. 17 is a schematic diagram illustrating an example of an equivalent contact resistance of a device under test of a High-side measurement circuit when a temperature detection circuit is provided;

FIG. 18 is a schematic diagram illustrating a Low-side measurement circuit equivalent contact resistance of a device under test with a temperature detection circuit according to an embodiment of the present invention;

fig. 19 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In order to solve the problem that the resistance of the contact resistor of the device under test cannot be accurately measured in the related art, the application provides a kelvin-based test circuit, as shown in fig. 1, the kelvin-based test circuit includes:

the current source IS, the voltmeter VM, a High-end current line Force High, a Low-end current line Force Low, a High-end voltage line Sense High and a Low-end voltage line Sense Low; one end of the High-end current line Force High and one end of the Low-end current line Force Low are respectively connected with a current source IS, the other end of the High-end current line Force High IS used for being connected with a first connector 1, and the other end of the Low-end current line Force Low IS used for being connected with a second connector 2; one end of the High-end voltage line Sense High and one end of the Low-end voltage line Sense Low are connected with the voltmeter VM, the other end of the High-end voltage line Sense High is used for being connected with a third connector 3, the other end of the Low-end voltage line Sense Low is used for being connected with a fourth connector 4, one end of the first connector 1 and one end of the third connector 3 are short-circuited, one end of the second connector 2 and one end of the fourth connector 4 are short-circuited, one short-circuited end of the first connector 1 and one short-circuited end of the third connector 3 are used for being connected into one end of a device under test, and one short-circuited end of the second connector 2 and one short-circuited end of the fourth connector 4 are used for being connected into the other end of the device under test; high-end current line Force High with be provided with first connecting circuit between the High-end voltage line Sense High, low-end current line Force Low with be provided with the second connecting circuit connection between the Low-end voltage line Sense Low, high-end voltage line Sense High with be provided with the third connecting circuit between the Low-end voltage line Sense Low, all be provided with on every connecting circuit and be used for controlling the switch that every connecting circuit switched on or cut off, the High-end current line the Low-end current line High-end voltage line and the Low-end voltage line all is provided with the switch.

It can be understood that, the two ends of the first connector 1 and the third connector 3 are short-circuited, and the two ends of the second connector 2 and the fourth connector 4 are short-circuited, wherein one end of the High-end current line Force High away from the current source IS connected with one end of the High-end voltage line Sense High away from the voltmeter VM, and the High-end measuring circuit IS formed by matching the upper switches of the connecting circuits and the upper switches of the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, and at this time, the High-end measuring circuit IS closed to obtain the resistance value of the closing resistor of the High-end measuring circuit; connecting one end of a Low-end current line Force Low far away from a current source IS with one end of a Low-end voltage line sensor Low far away from a voltmeter VM, forming the Low-end measuring circuit through the cooperation of the connecting circuits and switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line sensor High and the Low-end voltage line sensor Low, closing the Low-end measuring circuit to obtain the resistance value of the closed resistance of the Low-end measuring circuit, and then performing short circuit on one end of a subsequent High-end current line Force High far away from the current source IS and one end of a subsequent High-end voltage line sensor High far away from the voltmeter VM through a first connector 1 and a third connector 3 to form a High-end measuring circuit, wherein when a device to be tested IS tested, the interference of the closed resistance of the High-end measuring circuit on the device to be tested can be eliminated through the obtained combined resistance value of the one end of the device to be tested and the High-end measuring circuit, and then utilizing a difference value elimination method to eliminate the interference of the closed resistance of the High-end measuring circuit on the device to be tested, so that the contact resistance measurement IS more accurate; similarly, when the device to be tested IS tested, the obtained combined resistance value of the combined resistance of one end of the device to be tested and the Low-end measuring circuit can be used for eliminating the interference of the closed resistance of the Low-end measuring circuit on the device to be tested by using a difference elimination method, so that the contact resistance of one end of the device to be tested IS obtained, and the contact resistance measurement IS more accurate.

It can be appreciated that the above connectors include, but are not limited to: one of a probe, socket, gold Finger (Finger), etc.; for example, taking the connector as a probe as an example, in this case, the first connector 1 is a first probe, the second connector 2 is a second probe, the third connector 3 is a third probe, and the fourth connector 4 is a fourth probe.

In some examples, the kelvin-based test circuit is further provided with a voltage source and an ammeter, wherein the settings of the voltage source and the ammeter are set by related personnel according to actual use requirements of the test circuit, and are not described herein again. For better illustration, in the drawings, one end of a High-end current line Force High away from the current source IS denoted as FH _ OUT, one end of a Low-end current line Force Low away from the current source IS denoted as FL _ OUT, one end of a High-end voltage line Sense High away from the voltmeter VM IS denoted as SH _ OUT, and one end of a Low-end voltage line Sense Low away from the voltmeter VM IS denoted as SL _ OUT.

In some examples of this embodiment, a first connection point a is disposed on the High-side current line Force High, a second connection point B and a third connection point C are disposed on the High-side voltage line Sense High, the second connection point B is close to the voltmeter VM, the third connection point C is far from the voltmeter VM, a fourth connection point D and a fifth connection point E are disposed on the Low-side voltage line Sense Low, the fourth connection point D is close to the voltmeter VM, and the fifth connection point E is far from the voltmeter VM; a sixth connection point F is arranged on the Low-end current line Force Low; one end of the first connecting circuit is connected with the first connecting point A, and the other end of the first connecting circuit is connected with the second connecting point B; one end of the second connection circuit is connected with the fourth connection point D, and the other end of the second connection circuit is connected with the sixth connection point F; one end of the third connection circuit is connected to the third connection point C, and the other end of the third connection circuit is connected to the fifth connection point E. It should be understood that the above-described high-side measuring circuit or low-side measuring circuit is formed by controlling the turning on and off of the respective connection circuits.

In some examples of this embodiment, the switch in the kelvin-based test circuit IS a relay, and specifically, the High-end current line Force High IS provided with a first relay K1 on a side away from the current source IS and the first connection point a; the first connecting circuit is provided with a second relay K2; a third relay K3 is provided between the second connection point B and the third connection point C of the High-end voltage line Sense High; the third connecting circuit is provided with a fourth relay K4; a fifth relay K5 is arranged between the fourth connection point D and the fifth connection point E of the Low-side voltage line Sense Low; the second connecting circuit is provided with a sixth relay K6; a seventh relay K7 IS arranged on one side, far away from the current source IS and the sixth connection point F, of the Low-end current line Force Low; an eighth relay K8 is arranged on the High-end voltage line Sense High on the side far away from the second connection point B and the third connection point C; and a ninth relay K9 is arranged on the side, far away from the fourth connection point D and the fifth connection point E, of the Low-side voltage line Sense Low. It can be understood that each relay has two states of being closed and being opened, and the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High, the Low-end voltage line Sense Low, the first connecting circuit, the second connecting circuit and the third connecting circuit are controlled to be switched on and off by controlling the closing and the opening of each relay, so that the High-end measuring circuit or the Low-end measuring circuit is formed.

In the above example, specifically, the end of the High-end current line Force High far from the current source IS connected to the end of the High-end voltage line Sense High far from the voltmeter VM, and the first relay K1, the second relay K2, the fourth relay K4, the fifth relay K5, the sixth relay K6 and the eighth relay K8 are closed, when the other relays are disconnected, the High-end measuring circuit IS formed, at this time, the equivalent resistance circuit of the High-end measuring circuit can be obtained by turning on the High-end measuring circuit, at this time, the High-end measuring circuit IS equal to the sum of the resistance rK1 of the first relay K1, the resistance rK4 of the fourth relay K4, the resistance rK5 of the fifth relay K5, and the resistance rK8 of the eighth relay K8, that IS, and the resistance rH0 of the contact resistance when the end of the High-end current line Force High far from the current source IS connected to the end of the High-end voltage line Sense High far from the voltmeter VM, and the High-end measuring circuit = the High-end measuring circuit

rK1+ rK8+ rH0+ rK4+ rK5; similarly, the end of the Low-end current line Force Low far from the one end of the Low-end voltage line sensor Low far from the current source IS connected, and the end of the second relay K2, the third relay K3, the fourth relay K4, the sixth relay K6, the seventh relay K7 and the ninth relay K9 are closed, when other relays are opened, a Low-end measuring circuit IS formed, at this time, the Low-end measuring circuit IS turned on, and then the equivalent resistance circuit of the Low-end measuring circuit can be obtained, at this time, the Low-end measuring circuit IS equal to the resistance rK2 of the second relay K2, the resistance rK3 of the third relay K3, the resistance rK4 of the fourth relay K4, the resistance rK7 of the seventh relay K7, the resistance rK9 of the ninth relay K9, the end of the Low-end current line Force Low far from the current source IS, and the end of the voltage line sensor Low far from the voltage meter VM are connected together with the Low-end voltage line sensor Low, and then the sum of the contact resistance rL0 IS obtained, and the Low-end of the Low-end measuring circuit = rK3+ rK4+ rK9+ rL + 7.

It should be understood that the embodiment does not limit the on and off of the High-side current line Force High, the Low-side current line Force Low, the High-side voltage line Sense High, the Low-side voltage line Sense Low, the first connecting circuit, the second connecting circuit, and the third connecting circuit to be realized only by the closing and opening of the relay, and related personnel may flexibly use different switches according to the requirements to realize the on and off of the High-side current line Force High, the Low-side current line Force Low, the High-side voltage line Sense High, the Low-side voltage line Sense Low, the first connecting circuit, the second connecting circuit, and the third connecting circuit.

In some examples of this embodiment, the kelvin-based test circuit further comprises: and the controller is used for controlling the on and off of each relay so as to control the on and off of the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High, the Low-end voltage line Sense Low, the first connecting circuit, the second connecting circuit and the third connecting circuit. Specifically, the controller is used for controlling the first relay K1, the second relay K2, the fourth relay K4, the fifth relay K5, the sixth relay K6 and the eighth relay K8 to be closed to form a high-end measuring circuit; the controller is used for controlling the second relay K2, the third relay K3, the fourth relay K4, the sixth relay K6, the seventh relay K7 and the ninth relay K9 to be closed to form a low-end measuring circuit.

In some examples of this embodiment, the kelvin-based test circuit further comprises: a temperature detection circuit; the temperature detection circuit is used for detecting the ambient temperature of each relay in the Kelvin-based test circuit. Specifically, the temperature detection circuit includes: the temperature acquisition module is arranged near a High-end current line Force High, a Low-end current line Force Low, a High-end voltage line Sense High and a Low-end voltage line Sense Low to acquire the environmental temperatures of the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, specifically, for example, relays are arranged in the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, the temperature sensors are arranged near the relays to measure the environmental temperatures of the relays, the closed resistances of the High-end test circuit and the Low-end test circuit are recorded at this time, and the corresponding relations between the temperatures and the resistances of the High-end measurement circuit and the Low-end measurement circuit can be obtained;

in some examples, one end of the High-end current line Force High, which IS far away from the current source IS, in the kelvin-based test circuit IS connected with one end of the High-end voltage line Sense High, which IS far away from the voltmeter VM, and the High-end measurement circuit IS formed through cooperation of the connection circuits and switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, and the High-end measurement circuit IS turned on to obtain the closed resistance of the High-end measurement circuit; the high-end measuring circuit is conducted to obtain the temperature and the closed resistance when the high-end measuring circuit is closed, and the corresponding relation between the temperature and the resistance corresponding to the high-end measuring circuit is generated based on the temperature and the closed resistance when the high-end measuring circuit is closed; connecting one end, far away from a current source IS, of a Low-end current line Force Low in the Kelvin-based test circuit with one end, far away from a voltmeter VM, of a Low-end voltage line Sense Low, forming the Low-end measurement circuit through the matching of the connecting circuits and switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, conducting the Low-end measurement circuit to obtain the temperature and the closed resistance of the Low-end measurement circuit when the Low-end measurement circuit IS closed, and generating the corresponding relation between the temperature and the resistance corresponding to the Low-end measurement circuit based on the temperature and the closed resistance when the Low-end measurement circuit IS closed; the method comprises the steps that the testing temperature of the high-end measuring circuit when the device to be tested is obtained, and the corresponding closed resistance of the high-end measuring circuit when the device to be tested is determined based on the testing temperature and the corresponding relation between the temperature and the resistance corresponding to the high-end measuring circuit; and acquiring the test temperature of the low-end measuring circuit when the device under test is tested, and determining the corresponding closed resistance of the low-end measuring circuit when the device under test is tested based on the test temperature and the corresponding relation between the temperature and the resistance corresponding to the low-end measuring circuit.

The kelvin-based test circuit provided by the embodiment comprises: the current source IS, the voltmeter VM, a High-end current line Force High, a Low-end current line Force Low, a High-end voltage line Sense High and a Low-end voltage line Sense Low; one end of the High-end current line Force High and one end of the Low-end current line Force Low are respectively connected with a current source IS, the other end of the High-end current line Force High IS used for being connected with a first connector 1, and the other end of the Low-end current line Force Low IS used for being connected with a second connector 2; one ends of the High-side voltage line Sense High and the Low-side voltage line Sense Low are connected to the voltmeter VM, the other end of the High-side voltage line Sense High is used for being connected to the third connector 3, the other end of the Low-side voltage line Sense Low is used for being connected to the fourth connector 4, and the third connector 3 and the fourth connector 4 are used for being connected to a device under test; a first connecting circuit IS arranged between the High-end current line Force High and the High-end voltage line Sense High, a second connecting circuit IS arranged between the Low-end current line Force Low and the Low-end voltage line Sense Low, a third connecting circuit IS arranged between the High-end voltage line Sense High and the Low-end voltage line Sense Low, the testing circuit connects one end of the High-end current line Force High far away from the current source IS with one end of the High-end voltage line Sense High far away from the voltmeter VM, and the High-end measuring circuit IS formed by matching switches on the connecting circuits, the High-end current line Force High, the Low-end current line Force Low, the voltage line High-end Sense High and the Low-end voltage line Sense Low, and the High-end measuring circuit IS closed, so that the resistance value of the closed resistance of the High-end measuring circuit can be obtained; connecting one end of a Low-end current line Force Low far away from a current source IS with one end of a Low-end voltage line sensor Low far away from a voltmeter VM, forming the Low-end measuring circuit through the cooperation of the connecting circuits and switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line sensor High and the Low-end voltage line sensor Low, at the moment, closing the Low-end measuring circuit to obtain the resistance value of the closed resistance of the Low-end measuring circuit, further connecting one end of the High-end current line Force High far away from the current source IS with a first connector in the following process, connecting one end of the High-end voltage line sensor High far away from the voltmeter VM with a third connector, connecting the first connector and the third connector in a short circuit mode and then with one end of a tested device, forming the resistance value of the High-end measuring circuit when the tested device IS tested, and eliminating the interference of the closed resistance of the High-end measuring circuit on the tested device through the obtained combination of the High-end measuring circuit, obtaining the resistance value of the contact resistance of one end of the tested device, and enabling the contact resistance value of the High-end measuring circuit to be more accurate measurement; similarly, one end of the Low-end current line Force Low far away from the current source IS connected with the second connector 2, one end of the Low-end voltage line Sense Low far away from the voltmeter VM IS connected with the fourth connector 4, the second connector 2 and the fourth connector 4 are in short circuit and then connected with the other end of the device to be tested, when the device to be tested IS tested by the Low-end measuring circuit, the combined resistance value of one end of the device to be tested and the Low-end measuring circuit can be obtained, then the interference of the closing resistance of the Low-end measuring circuit on the device to be tested IS eliminated by utilizing the difference value elimination method, the contact resistance of one end of the device to be tested IS obtained, and the contact resistance measurement IS more accurate.

Based on the same concept, the present embodiment provides a testing method, as shown in fig. 2, the method includes:

s101, testing the combined resistance values of two ends of a tested device and a high-end measuring circuit and a low-end measuring circuit respectively through a Kelvin-based testing circuit;

s102, acquiring the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit in the Kelvin-based testing circuit;

s103, correcting the combined resistance values at the two ends of the tested device based on the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit to obtain the contact resistance values at the two ends of the tested device.

It can be understood that the test method provided by the present embodiment is applied to the kelvin-based test circuit described in the above embodiment. Specifically, if the combined resistance value of one end of the device under test and the high-end measuring circuit is measured to be X by the high-end measuring circuit, and the closed resistance of the high-end measuring circuit is measured to be Y, then at this time, the combined resistance value is corrected based on the closed resistance of the high-end measuring circuit by X-Y, so as to obtain the contact resistance value of one end of the device under test, and similarly, the combined resistance value is corrected based on the closed resistance of the low-end measuring circuit, so as to obtain the contact resistance value of the other end of the device under test.

In some examples, obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the kelvin-based test circuit includes: connecting one end, far away from a current source IS, of a High-end current line Force High in the Kelvin-based test circuit with one end, far away from a voltmeter VM, of a High-end voltage line Sense High, forming a High-end measurement circuit through the cooperation of the connecting circuits and switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, and conducting the High-end measurement circuit to obtain the closing resistance of the High-end measurement circuit; and connecting one end of the Low-end current line Force Low far away from the current source IS in the Kelvin-based test circuit with one end of the Low-end voltage line Sense Low far away from the voltmeter VM, forming the Low-end measuring circuit through the matching of the connecting circuits and the switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, and conducting the Low-end measuring circuit to obtain the closing resistance of the Low-end measuring circuit.

Specifically, for example, the High-end current line Force High IS provided with a first relay K1 on a side away from the current source IS and the first connection point a; the first connecting circuit is provided with a second relay K2; a third relay K3 is provided between the second connection point B and the third connection point C of the High-end voltage line Sense High; the third connecting circuit is provided with a fourth relay K4; a fifth relay K5 is arranged between the fourth connection point D and the fifth connection point E of the Low-side voltage line Sense Low; the second connecting circuit is provided with a sixth relay K6; a seventh relay K7 IS arranged on one side, far away from the current source IS and the sixth connection point F, of the Low-end current line Force Low; an eighth relay K8 is arranged on the High-end voltage line Sense High on the side far away from the second connection point B and the third connection point C; and a ninth relay K9 is arranged on the side, far away from the fourth connection point D and the fifth connection point E, of the Low-side voltage line Sense Low. It can be understood that each relay has two states of being closed and being opened, and the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High, the Low-end voltage line Sense Low, the first connecting circuit, the second connecting circuit and the third connecting circuit are controlled to be switched on and off by controlling the closing and the opening of each relay, so that the High-end measuring circuit or the Low-end measuring circuit is formed.

Bearing in the above example, specifically, one end of the High-end current line Force High far away from the current source IS connected with one end of the High-end voltage line sensor High far away from the voltmeter VM, and the first relay K1, the second relay K2, the fourth relay K4, the fifth relay K5, the sixth relay K6 and the eighth relay K8 are closed, when the other relays are opened, a High-end measuring circuit IS formed, at this time, the High-end measuring circuit IS turned on, so that an equivalent resistance circuit of the High-end measuring circuit can be obtained, at this time, the resistance value of the closed resistance of the High-end measuring circuit IS equal to the sum of the resistance value rK1 of the first relay K1, the resistance value rK4 of the fourth relay K4, the resistance value rK5 of the fifth relay K5 and the resistance value rK8 of the eighth relay K8, and the resistance value rH0 of the contact resistance when one end of the High-end current line Force High far away from the current source IS connected with one end of the voltage line sensor High far away from the voltmeter VM, i.e = rH0+ rK4+ rK5 + rK 4; similarly, the end of the Low-end current line Force Low far away from the current source IS connected with the end of the Low-end voltage line sensor Low far away from the voltmeter VM, the second relay K2, the third relay K3, the fourth relay K4, the sixth relay K6, the seventh relay K7 and the ninth relay K9 are closed, when other relays are opened, a Low-end measuring circuit IS formed, at this time, the equivalent resistance circuit of the Low-end measuring circuit can be obtained by turning on the Low-end measuring circuit, at this time, the resistance value of the closed resistor of the Low-end measuring circuit IS equal to the sum of the resistance value rK2 of the second relay K2, the resistance value rK3 of the third relay K3, the resistance value rK4 of the fourth relay K4, the resistance value rK7 of the seventh relay K7, the resistance value rK9 of the ninth relay K9, the resistance value rL0 of the contact resistor when one end of the Low-end current line Force far away from the current source IS connected with one end of the Low-end voltage line Sense Low far away from the voltmeter VM, that IS, the R Low-end measuring circuit = rK3+ rK4+ rK9+ rL0+ rK7.

In some examples, prior to obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the kelvin-based test circuit, the method further comprises: connecting one end, far away from a current source IS, of a High-end current line Force High in the Kelvin-based test circuit with one end, far away from a voltmeter VM, of a High-end voltage line Sense High, forming a High-end measurement circuit through the cooperation of the connecting circuits and switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, and conducting the High-end measurement circuit to obtain the closing resistance of the High-end measurement circuit; conducting the high-end measuring circuit to obtain the temperature and the closed resistance of the high-end measuring circuit when the high-end measuring circuit is closed, and generating the corresponding relation between the temperature and the resistance corresponding to the high-end measuring circuit based on the temperature and the closed resistance when the high-end measuring circuit is closed; connecting one end, far away from a current source IS, of a Low-end current line Force Low in the Kelvin-based test circuit with one end, far away from a voltmeter VM, of a Low-end voltage line Sense Low, forming the Low-end measurement circuit through the matching of the connecting circuits and switches on the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low, conducting the Low-end measurement circuit to obtain the temperature and the closed resistance when the Low-end measurement circuit IS closed, and generating the corresponding relation between the temperature and the resistance corresponding to the Low-end measurement circuit based on the temperature and the closed resistance when the Low-end measurement circuit IS closed. Specifically, the kelvin-based test circuit further includes a temperature detection circuit, and the temperature detection circuit includes: the temperature acquisition module is arranged near a High-end current line Force High, a Low-end current line Force Low, a High-end voltage line Sense High and a Low-end voltage line Sense Low to acquire the ambient temperature of the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High and the Low-end voltage line Sense Low; for example, a relay is arranged in the High-end current line Force High, the Low-end current line Force Low, the High-end voltage line Sense High, and the Low-end voltage line Sense Low, at this time, the temperature sensor is arranged near a relay switching loop and measures the ambient temperature, the closing resistance of the High-end test circuit and the Low-end test circuit is recorded, a temperature and resistance correspondence table corresponding to the High-end measurement circuit and the Low-end measurement circuit can be obtained, the resistance corresponding to each temperature of the High-end measurement circuit during the test can be found out through the temperature and resistance correspondence table corresponding to the High-end measurement circuit, and the resistance corresponding to each temperature of the Low-end measurement circuit during the test can be found out through the temperature and resistance correspondence table corresponding to the Low-end measurement circuit.

In the above example, it can be understood that the corresponding relationship may also be a curve relationship between temperature and environment, or a solution formula between temperature and environment.

In some examples, obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the kelvin-based test circuit includes: obtaining the testing temperature of the high-end measuring circuit when testing the device to be tested, and determining the corresponding closed resistance of the high-end measuring circuit when testing the device to be tested based on the testing temperature and the corresponding relation between the temperature and the resistance corresponding to the high-end measuring circuit; and acquiring the test temperature of the low-end measuring circuit when the device under test is tested, and determining the corresponding closed resistance of the low-end measuring circuit when the device under test is tested based on the test temperature and the corresponding relation between the temperature and the resistance corresponding to the low-end measuring circuit. Specifically, for example, the test temperature of the low-end measurement circuit when testing the device under test is x °, at this time, the resistance corresponding to x ° is found to be y in the temperature and resistance correspondence table corresponding to the low-end measurement circuit, at this time, the closed resistance of the low-end measurement circuit is determined to be y, and similarly, the closed resistance of the high-end measurement circuit can be obtained.

The method provided by the embodiment comprises the following steps: respectively testing the combined resistance values of two ends of the tested device and the high-end measuring circuit and the low-end measuring circuit through a Kelvin-based testing circuit; acquiring the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit in the Kelvin-based testing circuit; correcting the combined resistance values at two ends of the tested device based on the resistance value of the closed resistor of the high-end measuring circuit and the resistance value of the closed resistor of the low-end measuring circuit to obtain the contact resistance values at two ends of the tested device, and connecting one end of a high-end current line, which is far away from a current source, with a first connector, connecting one end of a high-end voltage line, which is far away from a voltmeter, with a third connector, and connecting the first connector and the third connector with one end of the tested device after short-circuiting the high-end voltage line, so that when the tested device is tested by the high-end measuring circuit, the obtained combined resistance value of one end of the tested device and the high-end measuring circuit can be used for eliminating the interference of the closed resistor of the high-end measuring circuit on the tested device by using a difference value, so as to obtain the resistance value of the contact resistor at one end of the tested device, and enable the contact resistance measurement to be more accurate; similarly, one end of the Low-end current line Force Low far away from the current source IS connected with the second connector 2, one end of the Low-end voltage line Sense Low far away from the voltmeter VM IS connected with the fourth connector 4, the second connector 2 and the fourth connector 4 are in short circuit and then connected with the other end of the device to be tested, when the device to be tested IS tested by the Low-end measuring circuit, the combined resistance value of one end of the device to be tested and the Low-end measuring circuit can be obtained, then the interference of the closing resistance of the Low-end measuring circuit on the device to be tested IS eliminated by utilizing the difference value elimination method, the contact resistance of one end of the device to be tested IS obtained, and the contact resistance measurement IS more accurate.

For better understanding of the present invention, the present embodiment provides a more specific example to illustrate the present invention, and the present embodiment provides a kelvin-based test circuit, the test circuit including: current source IS, voltmeter VM, high-end current line Force High, low-end current line Force Low, high-end voltage line Sense High, low-end voltage line Sense Low, wherein current source IS, voltmeter VM, high-end current line Force High, low-end current line Force Low, high-end voltage line Sense High, low-end voltage line Sense Low constitute kelvin detection circuit. This current source IS IS the constant current source, wherein, high-end current line Force High with be provided with first connecting circuit between High-end voltage line Sense High, low-end current line Force Low with be provided with the second connecting circuit connection between the Low-end voltage line Sense Low, high-end voltage line Sense High with be provided with the third connecting circuit between the Low-end voltage line Sense Low. And High-end current line Force High, low-end current line Force Low, high-end voltage line Sense High, low-end voltage line Sense Low, first connecting circuit, second connecting circuit and third connecting circuit are provided with first relay K1 through ninth relay K9 respectively, wherein, specific connection structure refers to above-mentioned embodiment, and the repeated description is not given here.

As shown in fig. 3, when the relays K1, K2, K4-K6, and K8 are closed and the other relays are opened, a high-end measuring circuit is formed;

as shown in FIG. 4, when the relays K2-K4, K6, K7 and K9 are closed and the other relays are opened, a low end measuring circuit is formed.

This example also provides a test method, specifically as follows:

the method comprises the following steps of firstly, acquiring the closed resistance of a high-end measuring circuit and a low-end measuring circuit before delivery.

When leaving the factory, the external Force High and Sense High of the VI source are respectively short-circuited, the ammeter is in constant current, the voltmeter VM is used for measuring the voltage, the High end measuring circuit and the Low end measuring circuit are respectively used for calculating the primary on-resistance,

wherein, force High and Sense High short circuit, as shown in FIG. 5, force Low and Sense Low short circuit, as shown in FIG. 6;

second, calculating and recording the internal on-resistance

At this time, an equivalent resistance circuit of the High-end measuring circuit can be obtained according to fig. 5, where, as shown in fig. 7, rK1, rK4, rK5, and rK8 are relay on resistances, rH0 is a contact resistance when the Force High and Sense High ends are short-circuited, and a total on resistance value when the High-end measuring circuit is closed, that is, a closing resistance R1 of the High-end measuring circuit is:

R1＝rK1+rK8+rH0+rK4+rK5。

similarly, according to fig. 6, the equivalent resistance circuit of the Low-end measurement circuit can be obtained, the equivalent resistance circuit of the Low-end measurement circuit is shown in fig. 8, rK3, rK4, rK7, rK9 are relay on resistances, rL0 is a contact resistance when the Force Low and Sense Low ends are short-circuited, and the total on resistance value when the Low-end measurement circuit is closed, that is, the closing resistance R2 of the Low-end measurement circuit is:

R2＝rK3+rK4+rK9+rL0+rK7。

the R1 and R2 resistance values are recorded.

Thirdly, when the contact resistance of the device to be measured is measured, the measuring circuit acts

When the contact resistance of the tested device IS measured, the current source IS of the High end measuring circuit and the Low end measuring circuit IS used for constant current, and the voltage of the voltmeter VM IS measured again, as shown in the figures 3 and 4.

The fourth step, calculating the sum of the internal on-resistance and the contact resistance of the device under test

According to fig. 3 and 4, the equivalent resistance circuit after the devices under test are added at the High end and the Low end, the contact resistance of the devices under test of the High end measuring circuit is equivalent to RH, and as shown in fig. 9, the contact resistance of the devices under test at the Low end is equivalent to RL. As shown in fig. 10, RH1 and RL1 are obtained, where RH1 is the combined resistance of the one terminal of the device under test and the high-side measuring circuit tested by the kelvin-based testing circuit; RL1 is the combined resistance of the other end of the device under test and the low-side measurement circuit tested by the Kelvin-based test circuit, i.e.

RH1＝RH+R1

RL1＝RL+R2。

A fifth step of compensating data using the internal on-resistance

And finally, respectively making a difference, and deducting the resistance values of the on-resistances R1 and R2 recorded in the factory to obtain the resistance values RH and RL of the contact resistance of the device to be tested.

RH＝RH1-R1

RL＝RL1-R2。

The kelvin-based test circuit provided by the embodiment mainly solves the problem that the resistance value of the contact resistor of the device to be tested cannot be accurately measured when kelvin measurement is performed. According to the test circuit provided by the invention, the contact resistance is measured through the Kelvin circuit, the influence of the on-resistance of the relay is eliminated by using a difference method, when the on-resistance of the relay is greatly influenced by temperature, the influence of the on-resistance of the relay is eliminated by using a temperature compensation method, and the measurement precision of the contact resistance is improved.

It can be understood that the temperature of the test environment of the repeated switch of the relay or the board card is often changed in the semiconductor test process, and at the moment, the on-resistance of most relays is affected by the temperature, and the resistance value is changed. In order to avoid that the on-resistance of the relay changes to cause the deviation of the internal on-resistance measurement result measured by a difference method to be large, a temperature compensation method is proposed on the basis of the difference method.

The kelvin-based test circuit provided by the example further comprises a temperature detection circuit, the temperature detection circuit is composed of a temperature acquisition module and a temperature sensor, and the position where the temperature sensor is placed is near the relay switching loop and measures the ambient temperature. The specific placement position may be on the tester board card (e.g., near the relay within the dashed box in the figure).

Specifically, as shown in fig. 11, K1, K2, K4 to K6, and K8 are closed, and the remaining relays are opened, so as to obtain a High-end measurement circuit.

As shown in fig. 12, K2-K4, K6, K7, and K9 are closed, and the other relays are opened, so as to obtain a Low end measurement circuit.

The test method comprises the following steps:

when leaving a factory, external Force High and Sense High of a VI source are in short circuit, an ammeter is in constant current, a voltmeter VM is in pressure measurement, the on-resistance (namely, closed resistance) after the output end is in short circuit is calculated for multiple times by using a High end measuring circuit and a Low end measuring circuit respectively, the resistance value Rn of the resistance is recorded, the temperature value Tn in the temperature sensor is recorded, and the relational expression of the on-resistance and the temperature is obtained through least square fitting.

R1n＝(k1Tn-R10)+b1

R2n＝(k2Tn-R20)+b2。

In the formula, R1n is the resistance value of the on-resistance when the High end is in short circuit, R2n is the resistance value of the on-resistance when the Low end is in short circuit, and n is the measurement times and can be 10000; r10 is the on-resistance when the High end measuring circuit is short-circuited obtained by the first measurement, and R20 is the on-resistance when the Low end measuring circuit is short-circuited obtained by the first measurement; k1 is a High-end slope obtained by least square fitting, and k2 is a Low-end slope obtained by least square fitting; b1 is the High end intercept obtained by least square fitting, and b2 is the Low end intercept obtained by least square fitting.

The High side measurement circuit is shorted as shown in fig. 13, and the Low side measurement circuit is shorted as shown in fig. 14.

The above calculation method for R1n is as follows, at this time, since the High-end equivalent resistance circuit is shown in fig. 15, rK1, rK4, rK5, rK8 are relay on resistances, rH0 is a contact resistance when the High-end is short-circuited, so the total on resistance value when the High-end is short-circuited, that is, the closed resistance R1 of the High-end measurement circuit is:

R1＝rK1+rK8+rH0+rK4+rK5。

r10 can be obtained by the first measurement, and R1n can be obtained after n times of measurement;

the above calculation method for R2n is as follows, since the Low-end equivalent resistance circuit is shown in fig. 16, rK3, rK4, rK7, rK9 are relay on resistances, rL0 is a contact resistance when the Low-end is short-circuited, and a total on resistance value when the Low-end is short-circuited, that is, the closed resistance R2 of the Low-end measurement circuit is:

R2＝rK3+rK4+rK9+rL0+rK7；

the first measurement gives R20 and n measurements give R2n.

While measuring the on-resistance, the temperatures T0, T1 … … Tn of the temperature sensors can be obtained, so that k1, k2, b1 and b2 in the formula can be calculated by a least square method, and the relational expression of R1 and R2 and the temperature T can be obtained:

R1＝(k1T-R10)+b1

R2＝(k2T-R20)+b2。

when the contact resistance of the device under test is measured, the external output end of the VI source board card is connected to the device under test, and an equivalent resistance circuit in which the High end and the Low end are added to the device under test can be obtained from fig. 11 and 12, where the equivalent resistance after the High end measurement circuit is added to the device under test is shown in fig. 17, and the equivalent resistance after the Low end measurement circuit is added to the device under test is shown in fig. 18. The High end device under test contact resistance is equivalent to RH, and the Low end device under test contact resistance is equivalent to RL. The current source IS IS used for keeping constant current, the voltmeter VM IS used for measuring the voltage and calculating the resistance values of the on-resistance of the relay at the High end and the Low end and the sum (namely the combined resistance value) RH1 and RL2 of the contact resistance of the tested device, namely the resistance values

RH1＝RH+R1

RL1＝RL+R2。

Meanwhile, a corresponding temperature value T is recorded through a temperature sensor, then the T is substituted into the relational expression of the temperature and the on-resistance, the resistance values (namely, the resistance values of the closed resistor) R1 and R2 of the on-resistance of the High-end relay and the Low-end relay are calculated, and finally the measured total resistance values RH1 and RL2 are subtracted from the calculated resistance values R1 and R2 to obtain the contact resistors RH and RL of the tested device.

RH＝RH1-R1

RL＝RL1-R2。

In order to solve the problem that the resistance of the contact resistor of the device to be tested cannot be accurately measured during kelvin measurement, according to the test method provided by the embodiment, the contact resistor is measured through the kelvin circuit, the influence of the on-resistance of the relay is eliminated by using a difference method, when the on-resistance of the relay is greatly influenced by temperature, the influence of the on-resistance of the relay is eliminated by using a temperature compensation method, and the measurement precision of the contact resistor is improved.

The embodiment of the application provides a testing device, testing device includes:

the test module is used for respectively testing the combined resistance values of the two ends of the tested device and the high-end measuring circuit and the low-end measuring circuit through a Kelvin-based test circuit;

an acquisition module for acquiring a closed resistance of the high-end measurement circuit and a closed resistance of the low-end measurement circuit in the Kelvin-based test circuit;

and the correction module is used for correcting the combined resistance values at the two ends of the tested device based on the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit to obtain the contact resistance values at the two ends of the tested device.

It should be understood that, the combination of the modules of the testing apparatus provided in this embodiment can implement the steps of the testing method, and achieve the same technical effects as the steps described above, and therefore, the details are not described herein again.

As shown in fig. 19, an electronic device according to an embodiment of the present application includes a processor 111, a communication interface 112, a memory 113, and a communication bus 114, where the processor 111, the communication interface 112, and the memory 113 complete mutual communication via the communication bus 114,

a memory 113 for storing a computer program;

in one embodiment of the present application, the processor 111, when executing the program stored in the memory 113, is configured to implement the steps of the method provided in any of the foregoing method embodiments.

Embodiments of the present application further provide a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the method as provided in any of the foregoing method embodiments.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A kelvin-based test circuit, the kelvin-based test circuit comprising: the current source, the voltmeter, the high-end current line, the low-end current line, the high-end voltage line and the low-end voltage line; it is characterized in that the preparation method is characterized in that,

one end of each of the high-end current line and the low-end current line is connected with a current source, the other end of each of the high-end current line and the low-end current line is used for being connected with a first connector, and the other end of each of the low-end current line and the high-end current line is used for being connected with a second connector; one end of the high-end voltage line and one end of the low-end voltage line are connected with the voltmeter, the other end of the high-end voltage line is used for being connected with a third connector, the other end of the low-end voltage line is used for being connected with a fourth connector, one end of the first connector and one end of the third connector are in short circuit, one end of the second connector and one end of the fourth connector are in short circuit, one end of the first connector and one end of the third connector in short circuit are used for being connected into one end of a device to be tested, and one end of the second connector and one end of the fourth connector in short circuit are used for being connected into the other end of the device to be tested;

high-end electric current line with be provided with first connecting circuit between the high-end voltage line, low-end electric current line with be provided with the second connecting circuit between the low side voltage line, high-end voltage line with be provided with the third connecting circuit between the low side voltage line, all be provided with on every connecting circuit and be used for controlling every connecting circuit switch-on or the switch that ends, high-end electric current line the low side electric current line high-end voltage line and the low side voltage line all is provided with the switch.

2. The kelvin-based test circuit of claim 1, wherein the high-side current line has a first connection point disposed thereon, the high-side voltage line has a second connection point and a third connection point disposed thereon, the second connection point is proximate to the voltmeter, the third connection point is distal from the voltmeter, the low-side voltage line has a fourth connection point and a fifth connection point disposed thereon, the fourth connection point is proximate to the voltmeter, and the fifth connection point is distal from the voltmeter; a sixth connection point is arranged on the low-side current wire;

one end of the first connecting circuit is connected with the first connecting point, and the other end of the first connecting circuit is connected with the second connecting point; one end of the second connecting circuit is connected with the fourth connecting point, and the other end of the second connecting circuit is connected with the sixth connecting point; one end of the third connecting circuit is connected with the third connecting point, and the other end of the third connecting circuit is connected with the fifth connecting point.

3. The kelvin-based test circuit of claim 2, wherein the switch in the kelvin-based test circuit is a relay; a first relay is arranged on one side, away from the current source and the first connecting point, of the high-end current line; the first connecting circuit is provided with a second relay; a third relay is arranged between the second connection point and the third connection point of the high-end voltage line; the third connecting circuit is provided with a fourth relay; a fifth relay is arranged between the fourth connection point and the fifth connection point of the low-side voltage line; the second connecting circuit is provided with a sixth relay; a seventh relay is arranged on one side, far away from the current source and the sixth connection point, of the low-end current line; an eighth relay is arranged on one side, far away from the second connection point and the third connection point, of the high-end voltage line; and a ninth relay is arranged on one side of the low-end voltage line, which is far away from the fourth connection point and the fifth connection point.

4. The Kelvin-based test circuit of claim 3, wherein the Kelvin-based test circuit further comprises: a controller;

the controller is used for controlling the first relay, the second relay, the fourth relay, the fifth relay, the sixth relay and the eighth relay to be closed to form a high-end measuring circuit;

the controller is used for controlling the second relay, the third relay, the fourth relay, the sixth relay, the seventh relay and the ninth relay to be closed to form a low-end measuring circuit.

5. The Kelvin-based test circuit according to any one of claims 1-4, wherein the Kelvin-based test circuit further comprises: a temperature detection circuit; the temperature detection circuit is used for detecting the ambient temperature of each relay in the Kelvin-based test circuit.

6. A method of testing, the method comprising:

respectively testing the combined resistance values of two ends of the tested device and the high-end measuring circuit and the low-end measuring circuit through a Kelvin-based testing circuit;

acquiring the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit in the Kelvin-based testing circuit;

and correcting the combined resistance values at the two ends of the tested device based on the closed resistance of the high-end measuring circuit and the closed resistance of the low-end measuring circuit to obtain the contact resistance values at the two ends of the tested device.

7. The method of claim 6, wherein obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the Kelvin-based test circuit comprises:

connecting one end, far away from a current source, of a high-end current line in the Kelvin-based test circuit with one end, far away from a voltmeter, of a high-end voltage line to form a high-end measurement circuit, and acquiring a closed resistance of the high-end measurement circuit;

and connecting one end of a low-end current line in the Kelvin-based test circuit, which is far away from the current source, with one end of a low-end voltage line, which is far away from the voltmeter, to form the low-end measurement circuit, and acquiring the closed resistance of the low-end measurement circuit.

8. The method of claim 6, wherein prior to obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the Kelvin-based test circuit, the method further comprises:

connecting one end, far away from a current source, of a high-end current line in the Kelvin-based test circuit with one end, far away from a voltmeter, of a high-end voltage line to form a high-end measurement circuit, acquiring the temperature and the closing resistance of the high-end measurement circuit when the high-end measurement circuit is closed, and generating a corresponding relation between the temperature and the resistance corresponding to the high-end measurement circuit based on the temperature and the closing resistance when the high-end measurement circuit is closed;

and connecting one end, far away from the current source, of the low-end current line in the Kelvin-based test circuit with one end, far away from the voltmeter, of the low-end voltage line to form the low-end measurement circuit, acquiring the temperature and the closing resistance of the low-end measurement circuit when the low-end measurement circuit is closed, and generating the corresponding relation between the temperature and the resistance corresponding to the low-end measurement circuit based on the temperature and the closing resistance when the low-end measurement circuit is closed.

9. The method of claim 8, wherein obtaining the on-resistance of the high-side measurement circuit and the on-resistance of the low-side measurement circuit in the kelvin-based test circuit comprises:

obtaining the testing temperature of the high-end measuring circuit when testing the device to be tested, and determining the corresponding closed resistance of the high-end measuring circuit when testing the device to be tested based on the testing temperature and the corresponding relation between the temperature and the resistance corresponding to the high-end measuring circuit;

and acquiring the test temperature of the low-end measuring circuit when the device under test is tested, and determining the corresponding closed resistance of the low-end measuring circuit when the device under test is tested based on the test temperature and the corresponding relation between the temperature and the resistance corresponding to the low-end measuring circuit.

10. A test apparatus, characterized in that the test apparatus comprises: