Method for determining at least one of first contact resistance and second contact resistance of two-wire Kelvin connection

Abstract

The present disclosure relates to a method for determining at least one of a first contact resistance and a second contact resistance of a two-wire Kelvin connection, the two-wire Kelvin connection being formed by contact of first and second measurement paths of a test device with a DUT. The method includes providing a predetermined measurement current to the DUT via a first measurement path during a first measurement in which the first and second measurement paths are coupled to the DUT, measuring a first voltage at an input node of an internal circuitry of the DUT to which the first and second measurement paths are coupled; at least one of a second measurement and a third measurement, the second measurement comprising providing a predetermined measurement current to the DUT via a first measurement path, measuring a second voltage at a first node of the first measurement path, and the third measurement comprising providing a predetermined measurement current to the DUT via a second measurement path, measuring a third voltage at a second node of the second measurement path; at least one of the first CRES and the second CRES is determined.

Description

Technical Field

[0001] This disclosure relates to determining the contact resistance (CRES) of a two-wire Kelvin connection. Specifically, examples of this disclosure relate to test apparatus and methods for determining at least one of a first CRES and a second CRES of a two-wire Kelvin connection. Background Technology

[0002] A two-wire Kelvin connection, also known as a Kelvin sensing connection or Kelvin measurement, is a method used in electrical measurements to minimize errors caused by the resistance of the connecting wires. It is typically used in situations requiring accurate measurement or the provision of low-resistivity components, such as for test circuits, sensors, or materials with low resistivity.

[0003] At the point where the two-wire Kelvin connection contacts the device under test (DUT), a corresponding CRES is introduced. CRES can affect the accuracy of the measurement or supply, especially when measuring or supplying low-resistance components or materials.

[0004] Therefore, it may be necessary to determine the CRES of the dual-wire Kelvin connection. Summary of the Invention

[0005] The subject matter of the independent claims satisfies this requirement. The dependent claims present advantageous embodiments.

[0006] According to a first aspect, this disclosure provides a method for determining at least one of a first CRES and a second CRES of a two-wire Kelvin connection formed through contact between a test device and a device under test (DUT) via a first measurement path and a second measurement path. The method includes: during a first measurement, in which both the first and second measurement paths are coupled to the DUT, providing a predetermined measurement current to the DUT via the first measurement path, and measuring a first voltage at an input node of an internal circuit device of the DUT coupled to both the first and second measurement paths. The method further includes at least one of a second measurement and a third measurement, wherein the second measurement determines the first CRES using only the first measurement path coupled to the DUT, and the third measurement determines the second CRES using only the second measurement path coupled to the DUT. The second measurement includes providing a predetermined measurement current to the DUT via the first measurement path and measuring a second voltage at a first node of the first measurement path. The third measurement includes providing a predetermined measurement current to the DUT via the second measurement path and measuring a third voltage at a second node of the second measurement path. The method further includes determining at least one of the first CRES and the second CRES. The first CRES is determined based on the predetermined measurement current, the first voltage, and the second voltage. The second CRES is determined based on the predefined measured current, first voltage, and third voltage.

[0007] According to the second aspect, this disclosure provides a test apparatus configured to perform the method according to the first aspect.

[0008] According to a third aspect, this disclosure provides a non-transient machine-readable medium having a program stored thereon, the program having program code for causing the test apparatus to execute the method according to the second aspect when the program is executed on a processor or programmable hardware of the test apparatus.

[0009] According to the fourth aspect, this disclosure provides a program having program code that, when executed on a processor or programmable hardware of a test apparatus, causes the test apparatus to perform the method according to the second aspect. Attached Figure Description

[0010] The following will describe some examples of apparatus and / or methods by way of example only and with reference to the accompanying drawings, wherein

[0011] Figure 1 The flowchart illustrates an example of a method for determining at least one of a first CRES and a second CRES for a two-line Kelvin connection;

[0012] Figure 2 An exemplary first measurement is illustrated;

[0013] Figure 3 An exemplary second measurement is illustrated;

[0014] Figure 4 An exemplary third measurement is illustrated;

[0015] Figure 5 The diagram shows Figures 2 to 4 An extended representation of the measurement setup illustrated;

[0016] Figure 6 The diagram shows Figure 5 Variations of the measurement setup illustrated; and

[0017] Figure 7 The diagram shows Figures 2 to 4 A variation of the measurement setup shown in the diagram. Detailed Implementation

[0018] Some examples will now be described in more detail with reference to the accompanying drawings. However, other possible examples are not limited to the features of these embodiments described in detail. Other examples may include modifications of features, as well as equivalents and alternatives to features. Furthermore, the terminology used herein to describe certain examples should not be limiting to other possible examples.

[0019] Throughout the description of the accompanying drawings, the same or similar reference numerals refer to the same or similar elements and / or features, which may be implemented in the same or modified form while providing the same or similar function. For clarity, the thickness of lines, layers, and / or regions in the drawings may also be exaggerated.

[0020] When using "or" to combine two elements A and B, this should be understood to disclose all possible combinations, namely only A, only B, and A and B, unless otherwise explicitly specified in individual cases. As alternative wording for the same combination, "at least one of A and B" or "A and / or B" can be used. The same applies to combinations of more than two elements.

[0021] If the singular form (such as "a", "an", and "the") is used, and the use of a single element is not explicitly or implicitly mandatory, other examples may also use several elements to achieve the same functionality. If the functionality is described below as being implemented using multiple elements, other examples may use a single element or a single processing entity to achieve the same functionality. It should also be understood that the terms "include", "including", "comprise", and / or "comprising" are used to describe the presence of a specified feature, integer, step, operation, process, element, component, and / or group thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, processes, elements, components, and / or groups thereof.

[0022] Figure 1 A flowchart illustrating a method 100 for determining at least one of a first CRES and a second CRES for a two-line Kelvin connection is shown below. Figures 2 to 4 The measurement setup 200 shown in the figure is further described in method 100.

[0023] like Figure 2 As illustrated, a two-wire Kelvin connection couples the test device 210 to the DUT 220. The two-wire Kelvin connection is formed through the contact of the first measurement path 230 and the second measurement path 240 of the test device 210 with the DUT 220.

[0024] DUT 220 can be any electronic or electrical component or system to be tested, analyzed, or evaluated by test apparatus 210. DUT 220 includes internal circuitry 221, such as electrostatic discharge (ESD) protection circuitry, transistors, resistors, capacitors, inductors (e.g., coils), and integrated circuits, or more thereof. Internal circuitry 221 may include additional, fewer, or different elements than those mentioned above. Internal circuitry 221 of DUT 220 may include analog circuitry, digital circuitry, or a combination thereof. As an example, DUT 220 may be or include a semiconductor device (e.g., a radar device).

[0025] In addition to the first measurement path 230 and the second measurement path 240, the test apparatus 210 also includes a current source 211 and a (e.g., high-ohm) voltmeter 212. The first measurement path 230 is electrically connected (coupled) to the current source 211. The second measurement path 240 is electrically connected (coupled) to the voltmeter 212. The first measurement path 230 is, for example, a force path of the test apparatus 210. The second measurement path 240 is, for example, a sensing path of the test apparatus 210.

[0026] By coupling the first measurement path 230 and the second measurement path 240 to the input node 222 of the internal circuitry 221 of the DUT 220, in Figure 2 The diagram schematically illustrates the coupling of the first measurement path 230 and the second measurement path 240 to the DUT 220. For example, both the first measurement path 230 and the second measurement path 240 can contact the DUT 220 via corresponding contact elements or probe tips (such as needles or Pogos (i.e., spring-loaded contact elements or probe tips)) of the test apparatus 210. For simplicity, in Figures 2 to 4 The corresponding contact element or probe is not illustrated. For example, the contact element or probe tip may be integrated into a socket into which the DUT 220 (will) be placed for testing, analysis, or evaluation by the test apparatus 210. The contact element or probe tip may, for example, contact at least one contact pad (test pad, platform) of the DUT 220. The contact pad is a conductive area of ​​the DUT 220, used to allow the internal circuitry 221 of the DUT 220 to be contacted by external devices (such as the test apparatus 210). The at least one contact pad is in Figure 2 The input node 222 is used to represent the schematic.

[0027] like Figure 2As illustrated, the first measurement path 230 and the second measurement path 240 each include switches 235 and 245, which are configured to switch between a conductive state and a non-conductive state to allow the corresponding measurement paths 230 and 240 to be selectively coupled to the DUT 220. For example, switches 235 and 245 may be relays.

[0028] A first node 231 of the first measurement path 230 and a second node 241 of the second measurement path 240 are electrically coupled via a coupling path 250. The first node 231 is positioned between a current source 211 and a switch 235. The second node 241 is positioned between a voltmeter 212 and a switch 245. The coupling path 250 is configured to selectively enable and disable current flow between the first node 231 and the second node 241. Figure 2 In the example, the coupling path includes a switch 255, which is configured to selectively electrically close or electrically disconnect coupling path 250. Accordingly, by electrically closing and disconnecting coupling path 250 via switch 255, current flow between the first node 231 and the second node 241 can be selectively enabled and disabled. For example, switch 255 may be a (Kelvin) relay.

[0029] At the points where the first measurement path 230 and the second measurement path 240 contact the DUT 220, corresponding CRES are introduced. The first CRES of the first measurement 230 is... Figure 2 Resistor 201 is represented in the diagram. Similarly, the second CRES of the second measurement path 240 is represented by... Figure 2 Resistor 202 is indicated in the diagram. CRES on the first measurement path 230 and the second measurement path 240 is a parasitic and unavoidable resistance, and may vary with various parameters such as contamination, wear temperature, etc. CRES can lead to inaccurate Kelvin measurements or even cause Kelvin measurement failure.

[0030] To determine at least one of a first CRES of the first measurement path 230 and a second CRES of the second measurement path 240, method 100 includes performing a first measurement 102, wherein both the first measurement path 230 and the second measurement path 240 are coupled to the DUT 220. For the first measurement 102, switches 235, 245 are in a conductive state to couple the first measurement path 230 and the second measurement path 240 to the DUT 220.

[0031] The current source 211 coupled to the first measurement path 230 is configured to provide a predetermined measurement current I. meas Measuring current I meas It is a constant current, meaning a current that does not change with time. Measuring current I. meas It can be a small current. For example, measuring current I.meas It can be -1mA or greater and 1mA or less. In some examples, the measured current I... meas It can be -100μA. When switch 235 is in the conductive state, the first measurement path 230 will measure the predetermined current I. meas The data is transported to the DUT 220. In other words, the first measurement 102 includes providing a predetermined measurement current I to the DUT 220 via the first measurement path 230. meas .

[0032] In the first measurement 102, switch 255 disconnects coupling path 250, so that no current flows in coupling path 250 between first node 231 and second node 241 in the first measurement. Correspondingly, no current flows in second measurement path 240.

[0033] The voltage measured by voltmeter 212 is the voltage V at input node 222 of the internal circuit device 221 of DUT 220. in In other words, the first measurement 102 includes measuring the first voltage V1 = V at the input node 222 of the internal circuitry 221 of the DUT 220'. in The first measurement path 230 and the second measurement path 240 are coupled to the input node of the internal circuitry device 221 of the DUT 220'.

[0034] Method 100 further includes (performing) at least one of a second measurement 104 for determining a first CRES and a third measurement 106 for determining a second CRES. In some examples, only one of the second measurement 104 and the third measurement 106 may be performed. In other examples, both the second measurement 104 and the third measurement 106 may be performed to determine both the first CRES and the second CRES.

[0035] Figure 3 The diagram illustrates the second measurement 104. (As shown...) Figure 3 As illustrated, for the second measurement 104, switch 235 is in a conductive state, while switch 245 is in a non-conductive state. Accordingly, in the second measurement 104, only the first measurement path 230 is coupled to the DUT 220. The second measurement path 240 is decoupled from the DUT 220 in the second measurement 104.

[0036] Switch 255 closes coupling path 250 in the second measurement 104. In the second measurement 104, no current flows in coupling path 250 between the first node 231 and the second node 241. The second measurement path 240 is open, meaning no current flows in the second measurement path 240.

[0037] When switch 235 is in the conductive state, the first measurement path 230 will transmit the predetermined measurement current I.meas The data is transported to the DUT 220. In other words, the second measurement 104 includes providing a predetermined measurement current I to the DUT 220 via the first measurement path 230. meas .

[0038] The voltage measured by voltmeter 212 is the voltage at the first node 231 of the first measurement path 230. The voltage at the first node 231 of the first measurement path 230 is the voltage V at the input node 222 of the internal circuit device 221 of the DUT 220'. in With the voltage drop V at the first measurement path 230 path_1 The sum. In other words, the second measurement 104 includes measuring the second voltage V2 = V at the first node 231 of the first measurement path 230. in +V path_1 .

[0039] Figure 4 The diagram illustrates the third measurement, 106. (As shown...) Figure 4 As illustrated, for the third measurement 106, switch 245 is in a conductive state, while switch 235 is in a non-conductive state. Accordingly, in the third measurement 106, only the second measurement path 240 is coupled to the DUT 220. In the third measurement 106, the first measurement path 230 is decoupled from the DUT 220.

[0040] Switch 255 closes the coupling path 250 in the third measurement 106. Accordingly, in the third measurement 106, the current (measuring current I)... meas The current flows in the coupling path 250 between the first node 231 and the second node 241. The first measurement path 230 is disconnected, that is, no current flows in the first measurement path 230.

[0041] When switch 245 is in the conductive state, the second measurement path 240 will measure the predetermined current I. meas The data is transported to the DUT 220. In other words, the third measurement 106 includes providing a predetermined measurement current I to the DUT 220 via the second measurement path 240. meas .

[0042] The voltage measured by voltmeter 212 is the voltage at the second node 241 of the second measurement path 240. The voltage at the second node 241 of the second measurement path 240 is the voltage V at the input node 222 of the internal circuit device 221 of the DUT 220'. in With the voltage drop V at the second measurement path 240 path_2 The sum. In other words, the third measurement 106 includes measuring the third voltage V3 = V at the second node 241 of the second measurement path 240. in +V path_2 .

[0043] Predicted measurement current I meas The first measurement 102, the second measurement 104 through the third measurement 106 are all the same. In each of the first measurement 102, the second measurement 104 through the third measurement 106, no current flows between voltmeter 212 and the second node 241. In other words, voltmeter 212 is a high-ohm (high-Z) voltmeter.

[0044] It should be noted that the first measurement 102, the second measurement 104, and the third measurement 106 can be performed in any temporal order. For example, the second measurement 104 can be performed after the first measurement 102, and the third measurement 106 can be performed after the second measurement 104. In other examples, one or both of the second measurement 104 and the third measurement 106 can be performed before the first measurement 102.

[0045] The voltages measured in the first measurement 102, the second measurement 104 to the third measurement 106 are used to determine a first CRES and / or a second CRES according to the proposed technique. In other words, method 100 further includes determining 108 at least one of the first CRES and the second CRES. The first CRES is based on a predetermined measurement current I. meas The first voltage V1 and the second voltage V2 are used to determine the second CRES. The second CRES is based on a predetermined measurement current I. meas It is determined by the first voltage V1 and the third voltage V3.

[0046] The first voltage V1 allows for the voltage V at the input node 222 of the internal circuitry 221 of the DUT 220' to be adjusted in each of the second voltage V2 and the third voltage V3. in The corresponding voltage components are compensated. The remaining components of the second voltage V2 and the third voltage V3 are related to the voltage drop at the corresponding measurement path. The voltage drop is caused by the corresponding CRES of the predetermined measurement current. This can be expressed as follows:

[0047] V path_1 =CRES path_1 ·I meas (1)

[0048] V path_2 =CRES path_2 ·I meas (2)

[0049] CRES path_1 The first CRES of the first measurement path 230 and CRES path_2 The second CRES identifies the second measurement path 240.

[0050] Method 100 allows for the determination of the first CRES of the first measurement path 230 and / or the second CRES of the second measurement path 240 individually and without any additional resources or components for each measurement path or conductor of the two-wire Kelvin connection. In high-volume production of the DUT, since no additional resources or components are required compared to those used for actual Kelvin measurements using the two-wire Kelvin connection, available test resources can be used to test more DUTs in parallel. In other words, test parallelism can be increased. Furthermore, the test time for individual DUTs 220 can be reduced.

[0051] Knowing the CRES of one or both measurement paths allows for more accurate Kelvin measurements because there are no parasitic effects from other components. For example, if a high CRES exists on the first measurement path (force path) 230, the test device 210 may attempt to compensate for this by conducting more current and / or voltage during the Kelvin measurement of the DUT 220. This could result in excessive voltage or overvoltage, which could in turn damage the test device 210 or its components. Accordingly, determining or monitoring the first CRES on the first measurement path 230 allows for prevention of damage to the test device 210 due to overvoltage. Additionally, determining or monitoring the first CRES on the first measurement path 230 allows for monitoring the contact quality of the contact between the first measurement path 230 and the DUT 220. During the Kelvin measurement, similar to the first measurement, no current flows in the second measurement path 240. Therefore, a high CRES on the second measurement path (sensing path) 240 is not critical. However, identifying or monitoring the second CRES on the second measurement path 240 can allow monitoring of the contact quality between the second measurement path 240 and the DUT 220.

[0052] The first CRES can be determined, for example, based on the difference between the second voltage V2 and the first voltage V1. For instance, the first CRES can be based on the difference between the second voltage V2 and the first voltage V1 and a predetermined measurement current I. meas The quotient is used to determine:

[0053]

[0054] Similarly, the second CRES can be determined, for example, based on the difference between the third voltage V3 and the first voltage V1. For instance, the second CRES can be determined based on the quotient of the difference between the third voltage V3 and the first voltage V1 and a predetermined measurement current.

[0055]

[0056] The first voltage V1 is used as a standard for calculating the individual CRES of one or both of the first measurement path 230 and the second measurement path 240. The voltage V at the input node 222 of the internal circuitry 221 of the DUT 220' is also used. in The first measurement 102, the second measurement 104 to the third measurement 106 are substantially the same.

[0057] As described above, the first measurement path 230 and the second measurement path 240 can be coupled to the DUT 220 via intermediate elements (such as contact elements or probe tips). Figure 5 The diagram shows Figures 2 to 4 The extended representation of the measurement setup 200 shown in the figure further highlights the additional intermediate elements. Figure 5 The measurement setup 500 shown in the diagram is based on Figures 2 to 4 The diagram illustrates measurement setting 200. The differences between measurement settings 200 and 500 will be described below. The contact pads of the DUT 220 are... Figure 2 The numbers are represented by elements 222 and 223.

[0058] Similar to measurement setup 200, measurement setup 500 includes test device 510. Test device 510 includes a tester (such as an automated test equipment (ATE)) 511, which includes a current source 211, a voltmeter 212, switches 235 and 245, a coupling path 250, and portions of a first measurement path 230 and a second measurement path 240. The functions of the above components are as described above.

[0059] The measurement setup 500 also includes a PCB 512 for coupling the tester 511 to a contact element (probe) 513. The contact element 513 is formed by a first pin or Pogo 530 for a first measurement path 230 and a second pin or Pogo 535 for a second measurement path 240. In other words, a corresponding pin or Pogo is arranged on each of the first measurement path 230 and the second measurement path 240. For example, the contact element 513 may be integrated into a socket in which the DUT 220 (will) be placed for testing, analysis, or evaluation by the test apparatus 510. The PCB 512 includes conductive traces and optionally includes electronic circuitry for coupling the tester 511 to the contact element 513. The conductive traces and optionally electronic circuitry of the PCB 512 provide additional resistance for each of the first measurement path 230 and the second measurement path 240. The additional resistance is provided by… Figure 5 Resistors 520 and 525 are represented in the first measurement path 230 and the second measurement path 240. Similarly, pins or Pogos 530 and 535 provide additional resistance for each of the first measurement path 230 and the second measurement path 240.

[0060] PCB 512 and contact element 513 can each be understood as hardware elements, including one or more hardware resistors arranged on at least one of the first measurement path 230 and the second measurement path 240.

[0061] The voltage drop at the corresponding measurement path depends not only on the corresponding CRES of the predetermined measurement current, but also on the additional resistance provided to the corresponding measurement path. This can be expressed as follows:

[0062] V path_1 =(CRES path_1 +R path_1 )·I meas (5)

[0063] V path_2 =(CRES path_2 +R path_2 )·I meas (6)

[0064] Where R path_1 The identifier is provided for the additional resistor in the first measurement path 230, and R path_2 The label indicates the additional resistor provided for the second measurement path 240.

[0065] When calculating the first CRES of the first measurement path 230 and the second CRES of the second measurement path 240, these resistors may optionally be considered. Specifically, the mathematical expressions (3) and (4) described above can be modified as follows to compensate for the additional hardware resistors:

[0066]

[0067] In other words, if the testing apparatus includes hardware components, such as one or more hardware resistors arranged on at least one of the first measurement path 230 and the second measurement path 240, then at least one of the first CRES and the second CRES can be further determined based on the resistance values ​​of the one or more hardware resistors.

[0068] exist Figure 5 In the example, tester 511 includes switches 235 and 245 for selectively coupling or decoupling the first measurement path 230 and the second measurement path 240 to or from the DUT 220. However, this disclosure is not limited thereto. Figure 6 The illustration shows an alternative measurement setup 600 with test device 610. (Compared to...) Figure 5Compared to the illustrated measurement setup 500, the tester 611 does not include switches 235 and 245. Instead, the PCB 612 includes switches 235 and 245. The functions of switches 235 and 245 are as described above. As is apparent from measurement setups 500 and 600, the positioning of switches 235 and 245 within the test device (i.e., along measurement paths 230 and 240) is not necessary for method 100. Alternatively or additionally, according to examples of this disclosure, coupling path 250 may be shifted to PCB 612.

[0069] In each of the above examples, coupling path 250 includes switch 255 for selectively enabling and disabling current flow between first node 231 and second node 241. However, the proposed technique is not limited thereto. According to the examples, switch 255 may be replaced by a (Kelvin) resistor. Figure 7 The corresponding measurement setup 700 is illustrated. Compared to measurement setup 200, switch 255 is replaced by (Kelvin) resistor 256. Similar to switch 255, resistor 256 allows current to flow in the coupling path 250 between first node 231 and second node 241 in the first measurement 102 and the second measurement 104. Similarly, in the third measurement 106, resistor 256 allows current to flow in the coupling path 250 between first node 231 and second node 241. The resistance of resistor 256 can be selected accordingly.

[0070] exist Figure 5 and Figure 6 In the illustrated measurement settings 500 and 600, switch 255 can be similarly replaced by resistor 256.

[0071] In an alternative example, in addition to switch 255, resistor 256 can be placed in coupling path 250.

[0072] Any of test device 210, test device 510, test device 610, and test device 710 can be configured to execute method 100. For example, test device 210, test device 510, test device 610, and test device 710 can be configured to automatically execute method 100. According to an example, test device 210, test device 510, test device 610, and test device 710 include memory configured to store a program having program code that, when executed by the respective test device 210, test device 510, test device 610, and test device 710, causes the test device to perform the steps and methods described herein.

[0073] In alternative examples, method 100 can be performed manually. In these examples, switches 235, 245, and 255 can be, for example, manually controllable switches. Alternatively, switches 235, 245, and 255 can be omitted, and measurement paths 230 and 240 can be decoupled / disconnected from the DUT 220 individually by being pulled out. Similarly, current flow on coupling path 250 can be suppressed by pulling out one or both of measurement paths 230 and 240.

[0074] The examples disclosed herein allow for the estimation of CRES on a two-wire Kelvin connection without the use of any additional instruments or components.

[0075] The examples described in this article can be summarized as follows:

[0076] An example (e.g., Example 1) relates to a method for determining at least one of a first CRES and a second CRES of a two-wire Kelvin connection formed through contact between a first measurement path and a second measurement path of a test apparatus and a device used for testing. The method includes: during a first measurement, in which both the first and second measurement paths are coupled to the DUT, providing a predetermined measurement current to the DUT via the first measurement path, and measuring a first voltage at an input node of an internal circuit device of the DUT to which the first and second measurement paths are coupled. The method also includes at least one of a second measurement and a third measurement, wherein the second measurement determines the first CRES using only the first measurement path coupled to the DUT, and the third measurement determines the second CRES using only the second measurement path coupled to the DUT. The second measurement includes providing a predetermined measurement current to the DUT via the first measurement path and measuring a second voltage at a first node of the first measurement path. The third measurement includes providing a predetermined measurement current to the DUT via the second measurement path and measuring a third voltage at a second node of the second measurement path. The method also includes determining at least one of the first CRES and the second CRES. The first CRES is determined based on the predetermined measurement current, the first voltage, and the second voltage. The second CRES is determined based on the predefined measurement current, the first voltage, and the third voltage.

[0077] Another example (e.g., Example 2) relates to a previous example (e.g., Example 1) or any other example, in which a first CRES is determined based on the difference between a second voltage and a first voltage, and a second CRES is determined based on the difference between a third voltage and a first voltage.

[0078] Another example (e.g., Example 3) relates to a previous example (e.g., Example 2) or any other example, wherein a first CRES is determined based on the quotient of the difference between a second voltage and a first voltage and a predetermined measuring current, and wherein a second CRES is determined based on the quotient of the difference between a third voltage and a first voltage and a predetermined measuring current.

[0079] Another example (e.g., Example 4) relates to a previous example (e.g., one of Examples 1 to 3) or any other example, wherein the test apparatus includes hardware elements comprising one or more hardware resistors arranged on at least one of a first measurement path and a second measurement path, wherein at least one of the first CRES and the second CRES is further determined based on the resistance value of the one or more hardware resistors.

[0080] Another example (e.g., Example 5) relates to a previous example (e.g., one of Examples 1 to 4) or any other example, where the first measurement path is the force path of the test device and the second measurement path is the sensing path of the test device.

[0081] Another example (e.g., Example 6) relates to the previous examples (e.g., one of Examples 1 to 5) or any other examples, where the measured current is -1mA or greater and 1mA or less.

[0082] Another example (e.g., Example 7) relates to a previous example (e.g., one of Examples 1 to 6) or any other example, wherein a first measurement path is connected to a current source configured to provide a predetermined measurement current, and wherein a second measurement path is connected to a voltmeter.

[0083] Another example (e.g., Example 8) relates to a previous example (e.g., one of Examples 1 to 7) or any other example, in which no current flows between the voltmeter and the second node in each of the first, second, to third measurements.

[0084] Another example (e.g., Example 9) relates to a previous example (e.g., one of Examples 1 to 8) or any other example, wherein the first node and the second node are electrically coupled through a coupling path, and wherein the coupling path is configured to selectively enable and disable current flow between the first node and the second node.

[0085] Another example (e.g., Example 10) relates to a previous example (e.g., Example 9) or any other example, wherein no current flows in the coupling path between the first and second nodes in the first and second measurements, and wherein current flows in the coupling path in the third measurement.

[0086] Another example (e.g., Example 11) relates to a previous example (e.g., one of Example 9 or 10) or any other example, wherein the coupling path includes a switch configured to selectively electrically close and electrically disconnect the coupling path.

[0087] Another example (e.g., Example 12) relates to a previous example (e.g., one of Examples 1 to 11) or any other example, wherein the first measurement path and the second measurement path each include a switch configured to switch between a conductive state and a non-conductive state to allow the corresponding measurement path to be selectively coupled to the DUT.

[0088] Another example (e.g., Example 13) involves a test apparatus configured to perform a method according to a previous example (e.g., one of Examples 1 to 12) or any other example.

[0089] Another example (e.g., Example 14) relates to a non-transient machine-readable medium on which a program has program code that, when executed on a processor or programmable hardware of a test apparatus, causes the test apparatus to perform a method according to a previous example (e.g., one of Examples 1 to 12) or any other example.

[0090] Another example (e.g., Example 15) involves a program with program code that, when executed on the processor or programmable hardware of the test apparatus, causes the test apparatus to perform a method according to a previous example (e.g., one of Examples 1 to 12) or any other example.

[0091] The aspects and features described in a particular example from the previous examples can also be combined with one or more of those from other examples to replace the same or similar features in those other examples or to additionally introduce features into those other examples.

[0092] Examples may also be or relate to (computer) programs that include program code, which, when executed on a computer, processor, or other programmable hardware component, perform one or more of the methods described above. Therefore, the steps, operations, or processes of the different methods described above may also be performed by a programmable computer, processor, or other programmable hardware component. Examples may also cover program storage devices (such as digital data storage media) that are machine-readable, processor-readable, or computer-readable and encoded and / or contain machine-executable, processor-executable, or computer-executable programs and instructions. For example, program storage devices may include or may be digital storage devices, magnetic storage media (such as disks and tapes), hard disk drives, or optically readable digital data storage media. Other examples may include computers, processors, control units, (field-programmable arrays) ((F)PLAs), (field-programmable gate arrays) ((F)PGAs), graphics processing units (GPUs), application-specific integrated circuits (ASICs), integrated circuits (ICs), or system-on-a-chip (SoC) systems programmed to perform the steps of the methods described above.

[0093] It should also be understood that the disclosure of steps, processes, operations, or functions in the specification or claims should not be construed as implying that these operations must depend on the described order, unless expressly stated in individual cases or necessary for technical reasons. Therefore, the preceding description does not limit the execution of steps or functions to a particular order. Furthermore, in other examples, a single step, function, process, or operation may include and / or be decomposed into several sub-steps, sub-functions, sub-processes, or sub-operations.

[0094] If aspects of a device or system have already been described, these aspects should also be understood as descriptions of the corresponding method. For example, blocks, device, or functional aspects of a device or system may correspond to features (such as method steps) of the corresponding method. Accordingly, aspects described about a method should also be understood as descriptions of corresponding blocks, elements, attributes, or functional features of the corresponding device or system.

[0095] The following claims are thus incorporated into the detailed description, wherein each claim may be considered an independent example. It should also be noted that although in the claims, dependent claims refer to a specific combination with one or more other claims, other examples may also include combinations of dependent claims with the subject matter of any other dependent or independent claim. Such combinations are expressly presented here unless, in individual cases, the statement of a particular combination is not intended. Furthermore, with respect to other independent claims, the features of the claim should also be included, even if the claim is not directly defined as dependent on that other independent claim.

Claims

1. A method (100) for determining at least one of a first contact resistance and a second contact resistance of a two-wire Kelvin connection, said two-wire Kelvin connection being formed through contact between a first measurement path and a second measurement path of a test apparatus and a device under test (DUT), said method (100) comprising: During a first measurement (102) in which both the first measurement path and the second measurement path are coupled to the DUT, a predetermined measurement current is provided to the DUT via the first measurement path, and a first voltage is measured at the input node of the internal circuit device of the DUT coupled to the first measurement path and the second measurement path; The method (100) further includes at least one of the following: The second measurement (104) determines the first contact resistance using only the first measurement path coupled to the DUT. The second measurement includes providing the predetermined measurement current to the DUT via the first measurement path and measuring a second voltage at a first node of the first measurement path. as well as The third measurement (106) determines the second contact resistance using only the second measurement path coupled to the DUT, the third measurement including providing the predetermined measurement current to the DUT via the second measurement path and measuring a third voltage at a second node of the second measurement path; The method (100) further includes determining (108) at least one of the first contact resistance and the second contact resistance, the first contact resistance being determined based on the predetermined measurement current, the first voltage and the second voltage, and the second contact resistance being determined based on the predetermined measurement current, the first voltage and the third voltage.

2. The method (100) according to claim 1, wherein: The first contact resistance is determined based on the difference between the second voltage and the first voltage, and The second contact resistance is determined based on the difference between the third voltage and the first voltage.

3. The method (100) according to claim 2, wherein the first contact resistance is determined based on the quotient of the difference between the second voltage and the first voltage and the predetermined measurement current, and wherein the second contact resistance is determined based on the quotient of the difference between the third voltage and the first voltage and the predetermined measurement current.

4. The method (100) according to any one of the preceding claims, wherein the test apparatus includes hardware elements, the hardware elements including one or more hardware resistors arranged on at least one of the first measurement path and the second measurement path, the first contact resistance and at least one of the second contact resistance being further determined based on the resistance value of the one or more hardware resistors.

5. The method (100) according to any one of the preceding claims, wherein the first measurement path is the force path of the test device, and the second measurement path is the sensing path of the test device.

6. The method (100) according to any one of the preceding claims, wherein the predetermined measurement current is -1 mA or greater and 1 mA or less.

7. The method (100) according to any one of the preceding claims, wherein the first measurement path is connected to a current source configured to provide the predetermined measurement current, and wherein the second measurement path is connected to a voltmeter.

8. The method (100) according to any one of the preceding claims, wherein in each of the first measurement, the second measurement to the third measurement, no current flows between the voltmeter and the second node.

9. The method (100) according to any one of the preceding claims, wherein the first node and the second node are electrically coupled through a coupling path, and wherein the coupling path is configured to selectively enable and disable current flow between the first node and the second node.

10. The method (100) of claim 9, wherein in the first measurement and the second measurement, no current flows in the coupling path between the first node and the second node, and wherein in the third measurement, current flows in the coupling path.

11. The method (100) of claim 9 or 10, wherein the coupling path includes a switch configured to selectively electrically close and electrically disconnect the coupling path.

12. The method (100) according to any one of claims 1 to 11, wherein the first measurement path and the second measurement path each include a switch configured to switch between a conductive state and a non-conductive state to allow the corresponding measurement path to be selectively coupled to the DUT.

13. A testing apparatus (210, 510, 610) configured to perform the method according to any one of claims 1 to 12.

14. A non-transient machine-readable medium having a program stored thereon, the program having program code that, when executed on a processor or programmable hardware of a test apparatus, causes the test apparatus to perform the method according to any one of claims 1 to 12.

15. A program having program code, which, when executed on a processor or programmable hardware of a test apparatus, causes the test apparatus to perform the method according to any one of claims 1 to 12.

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