Surface mountable device that couples test and measurement instruments to the device under test

Abstract

An apparatus for coupling a test and measurement instrument to a device under test includes a clip configured to be attached between two conductive portions of the device under test, and an insert configured to be removably mounted in the clip. The insert is configured to provide a current path between the two conductive portions of the device under test. In an embodiment, the insert includes a resistive element, which may be a round bar resistor. Additional embodiments may be described and / or claimed herein.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a continuation-in-part of U.S. non-provisional patent application 15 / 806,270, entitled “Probe Tip and Probe Assembly,” filed on November 7, 2017. In addition, this application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 821,972, entitled “Surface-Mountable Device for Coupling a Test and Measurement Instrument to a Device Under Test,” filed on March 21, 2019. Both of these related applications are incorporated herein by reference as if their entire contents were reproduced. Technical Field

[0003] The present disclosure relates to test and measurement systems, and more particularly to test and measurement probes. Background Art

[0004] Today's engineers are trying to test devices that carry high-speed serial buses. These devices can generally be considered, but are not limited to, double data rate second generation (DDR2) synchronous dynamic random access memory (SDRAM), double data rate fourth generation (DDR4) SDRAM, and peripheral component interconnect express (PCIe). The amplitude and pulse frequency of the voltage swings are very high, and the complexity of the signaling requires precise electrical probing. These and other buses have become very common in various types of consumer hardware devices. Each of these products has many test points of interest.

[0005] Test points in these products vary widely in both geometry and accessibility, and typically require one or two contact points. Typically, contact points include microtraces, vias, component pads, and connector contacts that provide electrical contact to, and therefore access to, high-speed signals. However, test points are not always on the same plane, and if two probe contacts are required at a time (for example, as in the case of differential probes), tip compliance is highly desirable to assist in positioning the probes for proper contact. Contact points can exist on PCA hardware at nearly every orientation angle, including vertical to horizontal. In these types of scenarios, test points are more easily accessed by probe tips that have compliance.

[0006] Although there are semi-permanent forms of probe contacts for these access points, including soldering or gluing wires to these points with conductive epoxy, this solution presents many disadvantages, including potential damage to the device under test (DUT) during connection, long setup time, and the need for superior dexterity to solder wires to these test points. In addition, semi-permanent contacts do not provide for rapid commissioning. Soldered probe tips tend to wear out after only a few connections, and thus create the need for replacement, which can be significantly expensive. Finally, due to the quality and geometry of the solder and / or epoxy connections, there is often high variability in signal fidelity, especially in higher signal frequencies.

[0007] Therefore, there remains a need for improved probe tips for use in conjunction with test probes. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An exploded view of an example of a probe tip in accordance with certain embodiments of the disclosed technology is shown.

[0009] Figure 2 Some embodiments of the disclosed technology are shown. Figure 1 Assembled view of the probe tip shown.

[0010] Figure 3 An example of a single tip test probe in accordance with certain embodiments of the disclosed technology is shown.

[0011] Figure 4 An example of a differential probe according to certain embodiments of the disclosed technology is shown.

[0012] Figure 5 is a graphical representation of an example of a frequency response graph of a test probe tip in accordance with certain embodiments of the disclosed technology.

[0013] Figure 6 is a depiction of an example round bar resistor according to various embodiments of the present disclosure.

[0014] Figure 7 is a depiction of an example round bar resistor according to various embodiments of the present disclosure.

[0015] Figure 8 An example of an apparatus for coupling a test and measurement instrument to a device under test according to various embodiments of the present disclosure is shown.

[0016] Fig. 9 Shows Figure 8 Example application for devices.

[0017] Fig.10Another example of an apparatus for coupling a test and measurement instrument to a device under test according to various embodiments of the present disclosure is shown.

[0018] Fig.11 Shows Fig.10 An example fabrication technique for a portion of a device.

[0019] Fig.12 is a graphical representation of an example of a frequency response graph for a device in accordance with certain embodiments of the disclosed technology. DETAILED DESCRIPTION

[0020] Embodiments of the disclosed technology generally include a probe tip adapted for use with a test probe and configured to provide precise, highly compliant, rapid, and light-pressure contact with a test point, e.g., on a device under test (DUT). In some embodiments, such a probe tip may be configured as a spring probe that includes a resistive or impedance element positioned near a point of contact with the DUT. The resistive or impedance element may greatly improve the pass-through response of the spring probe and may also significantly reduce DUT loading, thereby enabling high-speed signal acquisition.

[0021] Test probes and probe tips according to the disclosed technology can advantageously produce better physical and electrical control of the contact area between components of the probe tip, and also lend themselves well to fast debugging environments that typically cannot accommodate long contact establishment times. Test probes and probe tips according to the disclosed technology can advantageously provide excellent visibility for connection placement and intuitive operation of various categories of products, particularly handheld or quick-placement probe products.

[0022] Figure 1 An exploded view of an example of a test probe tip 100 according to certain embodiments of the disclosed technology is shown. In this example, the test probe tip 100 includes an optional compliance member or force deflection assembly and a tip component 108 coupled thereto.

[0023] In this example, the compliance member or force deflection assembly includes a barrel component 102 configured to be integrated or coupled with a test probe. The probe tip 100 also includes a resistive element 106 (e.g., a round rod resistor) and a plunger base component 104, which is configured to couple with an end surface of the resistive element 106, such as by electromechanical bonding (e.g., solder, conductive adhesive, etc.). In the following Figure 6 and 7 An illustrative resistor element is depicted in FIG.

[0024] In some embodiments, the resistor element 106 may have a tubular form, wherein the resistor is disposed on its outer circumference. For example, the resistor element 106 may include a resistive coating or layer covering the tube. In addition, in order to achieve electromechanical bonding, the resistor element 106 may include metallized contacts disposed on both ends of the resistor element 106. The tubular structure of the resistor can achieve high bandwidth, low bandwidth loads. The cylindrical shape of the resistor element 106 depicted can advantageously maximize the cross-sectional strength of the resistor element 106. It should be understood that although depicted as cylindrical, the resistor element 106 can also be implemented using another suitable shape (e.g., octagonal, triangular, etc.).

[0025] In this example, the tip component 108 is configured to couple, for example, via an electromechanical bond, to an end face of the resistor element 106 that is opposite to the end face coupled to the plunger base component 104. As used herein, an electromechanical bond is a bond that provides both electrical connectivity and structural / mechanical support. The tip component 108 may have, for example, one or more points for establishing or otherwise facilitating fine-grained electrical connectivity with one or more contact points on the DUT.

[0026] The spring mechanism may be captured or otherwise positioned within the barrel component 102, and the plunger base 104 may be configured to slide axially within the barrel component 102 and thereby be acted upon by the spring mechanism positioned within the barrel component 102 to advantageously create compression resistance.

[0027] Figure 2 An assembly view of an example of a test probe tip 200 according to certain embodiments of the disclosed technology is shown, the test probe tip 200 having an optional compliance member or force deflection assembly and a tip component coupled thereto. In this example, the barrel component 202 receives a plunger base 204, which is coupled to one end of a resistor element 206, such as by an electromechanical bond. The resistor element 206 may have a tubular form with a resistor on its outer circumference. In this example, the tip component 208 is coupled to one end of the resistor element 206, such as by an electromechanical bond, which is opposite to the end of the resistor element 206 coupled to the plunger base 204.

[0028] as Figure 1 With the illustrated test probe tip 100 , the spring mechanism may be captured or otherwise positioned within the barrel member 202 , and the plunger base 204 may be configured to slide axially within the barrel member 202 and be acted upon by the spring mechanism therein to advantageously generate compression resistance.

[0029] Figure 3 An example of a single tip test probe 300 according to some embodiments of the disclosed technology is shown. In this example, the test probe 300 includes a test probe body 302 and a test probe tip 304, such as a test probe body 302 and a test probe tip 304, respectively. Figure 1 and Figure 2 Test probe tips 100 and 200 are shown. A user may use test probe 300 to create a compressive resistance between a test probe tip 304 and a test point, such as a high-speed signal access point or other suitable point on a DUT.

[0030] Figure 4 4 shows an example of a differential probe 400 according to some embodiments of the disclosed technology. In this example, the differential probe 400 includes a probe body 402 and two test probe tips 404 and 406, such as Figure 1 and 2 Test probe tips 100 and 200 are shown. A user may use differential probe 400 to create a compressive resistance between either or both of test probe tips 404 and 406 and one or two test points, such as high-speed signal access points or other suitable points on a DUT.

[0031] Figure 5 is a graphical representation of an example of a frequency response plot of a test probe tip according to certain embodiments of the disclosed technology. The configuration of resistor manufacturing (e.g., rod-and-tube properties) and the close proximity of the contact points to the DUT contacts produce a very flat response to the signal on the DUT, resulting in high signal reproduction fidelity while keeping DUT loading to a minimum. This is important for measuring signal buses that are sensitive to loading. If the tip / probe input structure is loaded (e.g., reducing or changing the signal eye), the signaling between the transmitter-receiver is interrupted and the communication bus under test cannot function correctly, which can corrupt the test. The probe tip according to the disclosed technology advantageously greatly limits this problem.

[0032] Figure 6 6 is a depiction of a lengthwise cross section and two widthwise cross sections along lines 608 and 610 according to various embodiments of the present disclosure, depicted in like numbered boxes with an example resistor 600. As depicted, the resistor includes a structural member 602, metal layers 604a and 604b disposed around the circumference of both ends of the structural member 602, and a resistive layer 606 disposed on the outer surface of the round bar resistor.

[0033] Structural member 602 is made of a material that provides sufficient structural rigidity and sufficient strength to withstand the detection stress without breaking. In this way, structural member 602 can prevent the need for resistor 600 to be embedded in a packaging material. This can be beneficial because encapsulating the resistor in a packaging material (such as, for example, plastic) can have an adverse effect on the flatness of the frequency response of the resulting probe tip. In order to help maintain the flatness of the frequency response, it may be desirable that the only insulating material around resistor 600 is air, which is at least partially achieved by structural member 602. The material that provides sufficient structural rigidity and sufficient strength can vary based on the intended use of the probe tip, but can include zirconium, quartz, or any combination of these materials. It should be understood that these materials are only meant to illustrate possible materials, and other possible materials will be easily discernible to those of ordinary skill in the art. In addition, although structural member 602 is depicted as being generally cylindrical in nature, it should be understood that other shapes (e.g., octagonal, triangular, etc.) can be utilized without departing from the scope of the present disclosure.

[0034] The metal layers 604a and 604b may include any suitable material for forming electrical connections with the plunger base component 104 and the tip component 108. Such materials may include silver, gold, copper, or any other suitable conductive material, or a combination of any of these materials. The metal layers 604a and 604b may be applied using any suitable process, such as a micropenning process or any other suitable process. The metal layers may be formed as caps, or may be formed to expose both ends of the structural member.

[0035] The resistive layer 606 may be a thick film resistive layer. The film may be applied by a microjet process (e.g., a resistive ink, such as a resistive ink available from Ohmcraft), a flat screen, or any other suitable process. The resistive layer 606 may include, for example, an oxide of ruthenium, iridium, and / or rhenium, or any other suitable material. The resistive layer 606 may be applied to contact the metal layers 604a and 604b on the surface of the metal layer or between the metal layer and the structural member 602. Additionally, the resistive layer, or any other layer for that purpose, may be laser cut to obtain additional precision or to adjust the amount of resistance of the resistor (e.g., by removing portions of the resistive layer).

[0036] Figure 77 is another depiction of a lengthwise cross section and two widthwise cross sections along lines 708 and 710 according to various embodiments of the present disclosure, which are depicted in like numbered boxes of an example resistor 700. As depicted, the resistor includes semi-cylindrical structural members 702a and 702b, metal layers 704a and 704b disposed around the circumference of both ends of the structural member 702, and a resistive layer 706 disposed between the structural members 702a and 702b.

[0037] Structural members 702a and 702b are made of materials that provide sufficient structural rigidity and sufficient strength to withstand the detection stress without breaking. In this way, structural member 702 can prevent the need for resistor 700 to be embedded in the packaging material. This can be beneficial because the flatness of the frequency response of the resulting probe tip is adversely affected by encapsulating the resistor in a packaging material (such as, for example, plastic). In order to help maintain the flatness of the frequency response, it may be desirable that the only insulating material around resistor 700 is air, which is at least partially achieved by structural member 702. The material that provides sufficient structural rigidity and sufficient strength can vary based on the intended use of the probe tip, but can include zirconium, quartz, or any combination of one or more of these materials. It should be understood that these materials are only meant to illustrate possible materials, and other possible materials will be easily discernible to those of ordinary skill in the art.

[0038] The metal layers 704a and 704b may include any suitable material for forming electrical connections with the plunger base component 104 and the tip component 108. Such materials may include silver, gold, copper, or any other suitable conductive material, or any combination of these materials. The metal layers 704a and 704b may be applied using any suitable process, such as a micro-spraying process or any other suitable process. The metal layers may be formed as caps, or may be formed to expose both ends of the structural member.

[0039] The resistive layer 706 may be a thick film resistive layer. The film may be applied by a microjet process (e.g., a resistive ink, such as a resistive ink available from Ohmcraft), a flat screen, or any other suitable process. The resistive layer 706 may include, for example, an oxide of ruthenium, iridium, and / or rhenium, or any other suitable material. The resistive layer 606 may be applied to contact the metal layers 604a and 604b on the surface of the metal layer or between the metal layer and the structural member 602. Additionally, the resistive layer or any other layer for that purpose may be laser cut to obtain additional precision or to adjust the amount of resistance of the resistor (e.g., by removing portions of the resistive layer).

[0040] In conventional test and measurement systems, different types of probes are often used to couple different types of signals from a device under test (DUT) to a test and measurement instrument, such as an oscilloscope, in order to acquire, visualize, or perform various measurements on the signals. For example, test and measurement probes include voltage probes, current probes, optical probes, and radio frequency probes, among others.

[0041] Voltage probes are typically used to measure voltage signals from a DUT. Voltage probes are typically connected to the DUT using at least two probe contacts or probe tips that physically contact test points on the DUT, such as pins of an integrated circuit (IC), solder balls of a ball grid array (BGA) device, through holes or pads of a printed circuit board (PCB), connector pins, etc. When measuring a differential voltage signal, the two probe contacts are each connected to one of two corresponding test points of the DUT, each test point carrying one side of the differential signal. When measuring a single-ended signal, one probe contact is connected to a test point on the DUT that carries the signal, while the other probe contact is connected to a test point on the DUT that carries a reference voltage (such as the ground voltage of the DUT).

[0042] Current probes are commonly used to measure current signals from a DUT. In the DUT, the current probe is typically connected to the DUT using a non-contact probing method that forms a conductive loop or coil around a current-carrying conductor (such as a wire). The current probe is capable of sensing the magnitude and direction of a current flowing through the conductor and generating an electrical output signal representative of the current signal. The conductive loop of the current probe is typically formed by opening the jaws of the current probe, inserting a conductor into the jaws, and closing the jaws to form the loop. Current probes are often bulky because of the mechanical components required.

[0043] Embodiments of the presently disclosed technology generally provide a small form factor solution for probing and measuring either voltage signals or current signals or both in a DUT. In particular, embodiments enable the measurement of current signals within a DUT in a simple, non-destructive, miniature manner.

[0044] like Figure 8As shown, an embodiment includes an apparatus 800, which includes a small clip 810 or a socket-like device configured to be soldered into a DUT 802. For example, the clip 810 can be soldered between two parts 804a, 804b of a surface trace 804 on a PCB 802. The clip 810 is configured to be manually soldered in place, or to be processed by an automatic pick-and-place machine to be processed in the same manner as other electronic components (e.g., surface mount technology (SMT) components) through known PCB processing operations. A user can design and layout the PCB 802 to accommodate the placement of one or more clips 810. In debugging or troubleshooting applications, a user can cut the surface trace 804 of the PCB to form a gap in the trace, and then solder the clip 810 in place to bridge the gap. In other embodiments, the clip 810 can be fixed to the DUT 802 using a conductive adhesive instead of solder.

[0045] Once the clip 810 is mounted on the DUT 802, embodiments provide various modes of operation by installing various inserts 815 into the clip. The inserts 815 are configured to be easily installed into the clip 810, such as snapping into the clip 810, and easily removed from the clip 810 by a user. For example, the inserts 815 may have a circular cross-section, making them easier to install into the clip 810 because no specific orientation is required.

[0046] In a first exemplary mode, for normal DUT circuit operation, the user can install the zero ohm insert 820 into the clip. The zero ohm insert 820 acts as an electrical short circuit, as if the clip / insert combination 800 is not present in the DUT circuit. The zero ohm insert 820 may include a zero ohm resistor. In a preferred embodiment, the resistor may be a round bar resistor with good structural integrity and electrical performance, such as the round bar resistor described above.

[0047] In the second exemplary mode, in order to measure the voltage signal, the user can install a non-zero ohm resistance insert 830 into the clip 810. In other words, the user can install an insert 830 with a known resistance value. The known resistance value can be selected to be suitable for the signal being measured. Like the zero ohm insert 820, the resistance insert 830 can be a round bar resistor with good structural integrity. In the case where the resistance insert 830 is installed in the clip 810, the user can measure the voltage signal by, for example, clamping the voltage probe tip to the clip 810 so that it contacts the two ends 832, 834 of the resistance insert 830. Alternatively, the resistance insert 830 can be integrated into the probe itself, or integrated into the probe tip itself. In addition, the current signal can be determined by utilizing the relationship di / dt=(dv / dt) / R. For example, this determination of the current signal from the measured voltage signal can be performed by an oscilloscope that receives the output signal from the probe.

[0048] In a third exemplary mode, a user may install a current measurement insert 840 into the clip 810. The current measurement insert 840 may include a very short current loop and a Hall device. The insert 840 provides a shortened circuit connection for DUT 802 operation and provides a micro-Hall device for measuring a current signal. In addition, a voltage signal may be determined by utilizing the relationship di / dt=(dv / dt) / R. For example, such determination of a voltage signal from a measured current signal may be performed by an oscilloscope that receives an output signal from a probe.

[0049] Fig. 9 An exemplary embodiment of a device 900 is shown that includes a clip 910 and a zero ohm insert 920 mounted into the clip 910. The device 900 can be mounted onto a test PCB, where a signal trace is cut to form a gap, and the clip 910 is conductively attached to bridge the gap in the signal trace. A zero ohm round bar resistor 920 is mounted into the clip.

[0050] Fig.10 Another exemplary embodiment of the disclosed technology is shown. Fig.10 In the illustrated device 1000, the insert 1020 is a resistive insert having a microcoil 1026 substantially surrounding the perimeter of the insert 1020. Fig.10 As shown, with the combined insert 1020 installed in the clip 1010, the voltage signal can be measured by connecting the probe to both ends of the insert 1020, for example, by clamping the corresponding voltage probe tip so that it contacts the two ends 1022, 1024 of the insert 1020. The current signal can be measured by connecting the probe to both ends of the micro coil 1026. In addition, as mentioned above, by utilizing the relationship di / dt=(dv / dt) / R, the current signal can be determined from the measured voltage signal, and vice versa. This determination can be performed, for example, by an oscilloscope that receives the output signal from the probe.

[0051] like Fig.11 As shown, for example, a microcoil 1026 for a combination insert 1020 may be constructed by wrapping a very thin wire around a pin gauge 1110 . Fig.11 Depicted is the wire coiled around a 0.011 inch diameter pin gauge.

[0052] Fig.121 is a graph 1200 showing a comparison of the frequency response of a test circuit with and without the disclosed embodiments of the clip / insert system 800, 900, 1000. Trace 1210 is a trace of the frequency response of the unmodified test circuit, that is, without the clip or insert installed. Trace 1220 is a trace of the frequency response of the test circuit modified to have the clip installed, and the zero ohm insert installed in the clip. Trace 1230 is a trace of the frequency response of the test circuit modified to have the clip installed, and the resistive insert installed in the clip. Fig.12 As shown, the frequency response of the modified test circuit tracks the frequency response of the unmodified test circuit fairly well until about 20 GHz, and does not begin to deviate substantially from the frequency response of the unmodified test circuit until beyond 30 GHz.

[0053] Embodiments of the disclosed technology also include other types of inserts to perform other types of DUT signal measurements or tests. For example, in some embodiments, a signal injection insert may be installed into a clip to allow a user to easily inject a signal into a circuit in the DUT. This may be useful for measuring signals that are subject to interference or crosstalk. In other exemplary embodiments, a time domain reflectometer (TDR) or time domain transmissometer (TDT) insert may be installed into a clip. Such a TDR insert may allow a user to perform TDR measurements of the DUT circuit on one or both ends of the clip. These inserts may be connected to corresponding probes, or the inserts may be integrated into the probe itself or the probe tip itself.

[0054] The principles of the invention have been described and illustrated with reference to the illustrated embodiments, it should be appreciated that the illustrated embodiments may be modified in arrangement and detail and may be combined in any desired manner without departing from such principles. And although the foregoing discussion has focused on specific embodiments, other configurations are also contemplated.

[0055] In particular, even though expressions such as "according to an embodiment of the present invention" are used herein, these phrases are meant to generally refer to the possibility of embodiments and are not intended to limit the present invention to a specific embodiment configuration. As used herein, these terms may refer to the same or different embodiments that may be combined into other embodiments.

[0056] Therefore, in view of the various arrangements of the embodiments described herein, this detailed description and accompanying material are intended to be illustrative only and should not be taken as limiting the scope of the invention. Therefore, what is claimed as the present invention is all such modifications that may fall within the scope and spirit of the following claims and their equivalents.

Claims

1. An apparatus for coupling a test and measurement instrument to a device under test, comprising: a clip having a conductive first end, a conductive second end, and a non-conductive member connecting the first end and the second end, the clip being configured to be attached between two conductive portions of the device under test such that the clip bridges a non-conductive gap between the two conductive portions; a first insert configured to be removably mounted in the clip and to provide a substantially unimpeded current path between the two conductive portions of the device under test; and A second insert is configured to be removably mounted in the clip and provide a pair of signal measurement points for coupling to the test and measurement instrument.

2. The device according to claim 1, wherein: The first insert includes a zero-ohm resistor.

3. The device according to claim 2, wherein: The zero-ohm resistor comprises a round-bar resistor.

4. The device according to claim 1, wherein: The second insert includes a resistance element having a resistance value R greater than zero.

5. The device according to claim 4, wherein: The resistance element includes a round rod resistor.

6. The device according to claim 4, wherein: The resistance value is selected based on an expected amplitude range of a signal to be measured between the two conductive portions of the device under test.

7. The device according to claim 4, wherein: The two ends of the resistance element provide the pair of signal measurement points, and the pair of signal measurement points are coupled to the test and measurement instrument through probes.

8. The device according to claim 7, wherein: The test and measurement instrument is configured to measure a voltage signal v(t).

9. The device according to claim 8, wherein: The test and measurement instrument is also configured to determine the current signal i(t) by using the relationship di(t) / dt=(dv(t) / dt) / R.

10. The apparatus of claim 4, further comprising a microcoil surrounding the resistive element, the microcoil having a pair of leads to provide the pair of signal measurement points.

11. The device according to claim 10, wherein: The pair of leads provides a voltage signal proportional to the current flowing through the resistive element.

12. The device according to claim 10, wherein: The pair of leads is coupled to the test and measurement instrument through a probe.

13. The device according to claim 12, wherein: The test and measurement instrument is configured to determine a magnitude and direction of a current flowing through the resistive element based on a voltage signal from the pair of leads.

14. The apparatus according to claim 1, wherein: The clips are configured to be handled by automated SMT pick and place machines.

15. The apparatus according to claim 1, wherein: The second insert includes a portion of a probe tip.

16. The apparatus according to claim 1, wherein: The second insert comprises a current measurement insert including a conductive wire loop providing a substantially unimpeded current path between the two conductive portions of the device under test, and a Hall device for detecting current flowing through the loop, and wherein an output of the Hall device provides the pair of signal measurement points.

17. The device according to claim 16, wherein: The second insert is integrated into the current probe.

18. A test and measurement system comprising: a clip having a conductive first end, a conductive second end, and a non-conductive member connecting the first end and the second end, the clip being configured to be attached between two conductive portions of a device under test such that the clip bridges a non-conductive gap between the two conductive portions; a first insert configured to be removably mounted in the clip and to provide a substantially unimpeded current path between the two conductive portions of the device under test; Oscilloscope; and A probe, wherein a probe tip of the probe includes a second insert configured to be removably mounted in the clip, the probe tip being configured to output a voltage signal indicative of a current passing through the second insert, the probe coupling an output of the probe tip to an input of the oscilloscope.

19. The test and measurement system of claim 18, wherein: The first insert and the second insert each include a round bar resistor.

20. A method for configuring an operation mode of a device under test (DUT), the method comprising: attaching a clip between two conductive portions of the DUT such that the clip bridges a non-conductive gap between the two conductive portions, the clip having a conductive first end, a conductive second end, and a non-conductive member connecting the first end and the second end; For a normal operating mode of the DUT, installing a first insert into the clip, the first insert being configured to be removably mounted in the clip and to provide a substantially unimpeded current path between the two conductive portions of the DUT; as well as For a measurement mode of operation of the DUT, a second insert is mounted in the clip, the second insert being configured to be removably mounted in the clip and providing a pair of signal measurement points for coupling to a test and measurement instrument.

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