insert

Abstract

An insert for a test system includes coaxial cables each configured to deliver a first portion of electrical current originating from an electrical current source and printed circuit boards (PCBs) each connected to a set of coaxial cables to receive the first portion of the electrical current from each coaxial cable in the set and to deliver a second portion of the electrical current. A spring finger assembly includes spring fingers each connected to a PCB to deliver a third portion of the electrical current obtained from the PCB to a device interface board (DIB) connected to a device under test (DUT) to be tested by the test system. The coaxial cables on each PCB are arranged in parallel, the PCBs are arranged in parallel, and the spring fingers on each PCB are arranged in parallel.

Description

Technical Field

[0001] This specification describes an example of an insert configured to act as an interface to a device such as a Device Interface Board (DIB) in a test system. Background Technology

[0002] Exemplary inserts include interconnects for transmitting signals between a source and a destination. For example, an insert may include electrical pathways to transmit electrical signals between components of a system. Summary of the Invention

[0003] An insert for a test system includes coaxial cables and printed circuit boards (PCBs). Each coaxial cable is configured to deliver a first portion of a current originating from a current source. Each PCB is connected to a set of coaxial cables to receive the first portion of the current from each of the coaxial cables in the set and to deliver a second portion of the current. A spring sheet assembly includes spring sheets, each of which is connected to the PCB to deliver a third portion of the current received from the PCB to a device interface board (DIB), which is connected to a device under test (DUT) to be tested by the test system. The coaxial cables (including the inner and outer conductors of the coaxial cables on each PCB) are arranged in parallel, as are the spring sheets on each PCB. Exemplary inserts may include one or more of the following features (individually or in combination).

[0004] For currents of 2000 amps (A) or greater, the insert can have an inductance of 100 nanohenries (nH) or less. For currents of 2000 amps (A) or greater, the insert can have a resistance of 3 milliohms (mΩ) or less. For currents of 2000 amps (A) or greater, the insert can have an inductance of 500 nanohenries (nH) or less. For currents of 2000 amps (A) or greater, the insert can have a resistance of 10 milliohms (mΩ) or less.

[0005] The first part of an electric current can be different from the second part. The first part of an electric current can be equal to the third part. The second part of an electric current can be different from the third part. The second part of an electric current can be different from both the first and third parts.

[0006] On each PCB, a set of spring contacts can be arranged such that adjacent spring contacts have different polarities. Each coaxial cable may include a center conductor and a shield surrounding the center conductor. The shield may include a loop for current to be transmitted through the center conductor. The shield and center conductor can achieve at least some inductance cancellation. The shield and center conductor can maximize inductance cancellation.

[0007] The insert may include a shield made of electrically insulating material. The shield may at least partially surround the spring assembly. The insert may be part of a blind-fit connection within the test head of a test system. The insert may include electrically insulating material separating each PCB in a PCB. Each PCB may include a surge suppressor to prevent voltage or current spikes on the PCB.

[0008] Coaxial cables, PCBs, and spring clips can be configured and arranged to achieve the target resistance and target inductance of the insert. The insert can be connected to low-inductance copper pads on the DIB within an area of ​​2 inches (5.08 cm) by 3 inches (7.62 cm) or smaller.

[0009] An exemplary test system includes a device interface board (DIB) for connection to a device under test (DUT) and a test head including a blind-mating connector to the DIB. The blind-mating connector includes an insert assembly. The insert assembly includes coaxial cables and printed circuit boards (PCBs), each of the coaxial cables being configured to deliver a first portion of current originating from a current source, and each PCB being connected to a set of coaxial cables to receive the first portion of the current from each of the coaxial cables in the set and to deliver a second portion of the current. A spring sheet assembly includes spring sheets, each of the spring sheets being connected to the PCB to deliver a third portion of the current received from the PCB to the DIB. The coaxial cables on each PCB are arranged in parallel, the PCBs are arranged in parallel, and the spring sheets on each PCB are arranged in parallel. The exemplary test system may include one or more of the following features (individually or in combination).

[0010] Coaxial cables can have lengths defined as two-digit meters or less, one-digit meters or less, one-digit decimeters or less, or one-digit centimeters or less. Coaxial cables, PCBs, and spring contacts can be configured and arranged to reduce or minimize the resistance and inductance of the insert assembly. Coaxial cables, PCBs, and spring contacts can be configured and arranged to achieve target resistance and target inductance of the insert assembly.

[0011] Any two or more of the features described in this specification (including the content section) may be combined to form specific embodiments not specifically described in this specification.

[0012] At least a portion of the systems and techniques described herein can be configured or controlled by executing instructions stored on one or more non-transitory machine-readable storage media on one or more processing devices. Examples of non-transitory machine-readable storage media include read-only memory, optical disc drives, memory disk drives, and random access memory. At least a portion of the systems and techniques described herein can be configured or controlled using a computing system comprising one or more processing devices and a memory storing instructions that can be executed by the one or more processing devices to perform various control operations (including high-current testing). Some of the devices, systems, and / or components described herein can be configured, for example, by design, construction, arrangement, placement, programming, operation, activation, deactivation, and / or control.

[0013] The accompanying drawings and the following detailed description illustrate one or more specific embodiments. Other features and advantages will become apparent from the details, the drawings, and the claims. Attached Figure Description

[0014] Figure 1 This is a side view drawing of an exemplary insert.

[0015] Figure 2 This is a side perspective drawing of an exemplary insert.

[0016] Figure 3 This is a front perspective drawing of an exemplary insert.

[0017] Figure 4 A top perspective photograph of an exemplary insert.

[0018] Figure 5 This is a block diagram of an exemplary test system including inserts.

[0019] Figure 6 An exemplary pad to which the insert is connected is shown.

[0020] Similar reference numerals in different figures indicate similar elements. Detailed Implementation

[0021] Exemplary inserts include interconnects for transmitting signals between a source and a destination. For example, an insert may include electrical conductors to transmit electrical signals between components of a test system.

[0022] An exemplary insert includes coaxial cables, each configured to deliver a first portion of a current originating from a current source. The exemplary insert also includes a printed circuit board (PCB), each PCB connected to a set of coaxial cables to receive the first portion of the current from each of the coaxial cables in the set and to deliver a second portion of the current. A spring sheet assembly includes spring sheets, each connected to the PCB to deliver a third portion of the current received from the PCB to a device interface board (DIB), which is connected to a device under test (DUT) to be tested by the test system. The inner and outer conductors of the coaxial cables on each PCB are arranged in parallel, the PCBs are arranged in parallel, and the spring sheets on each PCB may be arranged in parallel. In some specific implementations, two or more (e.g., all three) of the first, second, or third portions of the current may be different.

[0023] The specific implementation of the insert allows relatively high currents to be transmitted through it with relatively low inductance and resistance. In this respect, inductance refers to the tendency of an electrical conductor to resist changes in the current flowing through it. Resistance is a measure of the resistance to current flowing through a conductor. Therefore, it is preferable to maintain low inductance and resistance values. Regarding inductance, in some implementations, the current flowing through the insert is pulsed at least partly or all of the time. Pulsed currents can include rapid, transient changes in amplitude from a baseline value such as "0" to a higher or lower value, followed by a rapid return to the baseline value. For example, in some implementations, the current is periodic. Reducing inductance reduces the resistance to such current changes.

[0024] Examples of high current include, but are not limited to, currents exceeding 500 amperes (A), 1000 A, 2000 A, 3000 A, or greater. Examples of low inductance include, but are not limited to, 100 nanohenries (nH) to 60 nH or less. Examples of low resistance include 10 milliohms (mΩ) or less, or 3 mΩ or less.

[0025] The specific implementation of the insert can be relatively small in terms of physical dimensions. For example, refer to... Figure 6 The insert can be connected to a low-inductance copper pad 80 on a DIB (or probe card) area within an area of ​​2 inches (5.08 cm) by 3 inches (7.62 cm) or smaller. In one example, the insert is connected to the DIB within an area of ​​1.5 inches (3.81 cm) by 2.5 inches (6.35 cm). The parallel conductors included in the insert enable such a small size while maintaining relatively low resistance and inductance values ​​even at relatively high currents. However, inserts with the characteristics described herein are not limited to any particular size or value of resistance, inductance, or current.

[0026] Figures 1 to 4 An exemplary embodiment of insert 10 is shown, which may have features similar to those described in the preceding paragraphs. Insert 10 includes PCBs 12, 13, 14, 15, 16, and 17. Although in Figures 1 to 4 The specific implementation includes six PCBs, but the insert 10 may include more or fewer than six PCBs. Each PCB includes a non-conductive substrate such as G10 FR-4, which is a glass-reinforced epoxy laminate. One or more conductive conduits pass through or extend over the substrate to carry electrical signals (such as current) from the input of each PCB to the output of each PCB. Generally, the more signal paths through a PCB, the lower the resistance and inductance of that PCB will be.

[0027] Non-conductive spacers 20, 21, 22, 23, and 24 separate adjacent PCBs within the insert. Non-conductive spacers 20 to 24 may be made of G10 FR-4 or any suitable dielectric (i.e., non-conductive material). Figure 3 As shown, in some specific implementations, each PCB may also include a surge suppressor 26 to prevent voltage spikes or current spikes on the PCB.

[0028] Each PCB input includes multiple coaxial cables 30. Figures 1 to 4 In the exemplary configuration, each PCB has six coaxial cables 31, 32, 33, 34, 35, and 36. Each coaxial cable 30 can be connected to the PCB using an edge plating layer 29, wherein each cable is spliced ​​and soldered to the PCB. Although in Figures 1 to 4 Each board is shown with six coaxial cables, but insert 10 may include more than six coaxial cables per PCB or fewer than six coaxial cables per PCB. Therefore, in Figures 1 to 4 In the example, there are a total of 36 coaxial cables on insert 10. Each coaxial cable includes an inner conductor surrounded by a concentric conductive shield. The inner conductor and the concentric conductive shield are separated by a dielectric. Each coaxial cable also includes a protective outer sheath, which is also non-conductive. Current flows through the inner conductor of each coaxial cable 30, where the concentric conductive shield acts as the return path for the current. For example, a forced high (or positive) current can pass through the inner conductor and a forced low (or negative) current can pass through the outer conductor, where the forced high and forced low currents correspond to currents with different polarities. By using a center conductor and a concentric conductive shield to transmit the forced high current signal and the forced low current signal respectively, the inductance in the coaxial cable can be limited or reduced through inductance cancellation. Additionally, a thin dielectric, such as that in the range of 2 mils (0.5 mm) to 10 mils (0.25 mm), can also contribute to inductance cancellation.

[0029] Coaxial cables used in a PCB are electrically connected to conductive conduits within the PCB via edge plating technology. For example, the inner conductor of the coaxial cable may be electrically connected to a first set of conductive conduits in the PCB, where the first set may include one or more conductive conduits. The outer (or return) conductor of the same coaxial cable may be electrically connected to a second set of conductive conduits in the PCB, where the second set may include one or more conductive conduits different from the first set. Different coaxial cables can be connected to different sets of conduits on the PCB in this manner. Current from the coaxial cable connected to the PCB (such as PCB 17) thus flows through the PCB, and the return path also passes through the PCB. In some specific implementations, multiple sets of conductive conduits on the PCB carrying currents of different polarities are adjacent. For example, no two sets of conductive conduits on the PCB can carry currents of the same polarity. This can create at least some induced cancellation on the PCB.

[0030] The outputs of each PCB 12 to 17 also include spring sheet assembly 40 (see...). Figure 1 Each PCB may include an edge plating layer to enable such connections. Each spring sheet assembly 40 includes a plurality of spring sheets 41, 42, 43, and 44. Each spring sheet includes a conductive material that is electrically connectable to one or more conductive conduits in a conductive conduit on the PCB. The spring sheet may include compressible, preloaded spring fingers to provide stable electrical contact. Figure 1 and Figure 3 As shown, in some implementations, there are four spring tabs on each PCB; however, in some implementations, each PCB may have a different number of spring tabs.

[0031] In some implementations, each spring contact is connected to a corresponding PCB to deliver a portion of the current drawn from the PCB to the device interface board (DIB) of the test system. The spring contact connectors can be arranged with alternating polarities. For example, in the case of four spring contact connectors on the PCB, a first spring contact connector 41 can be used to force a high current path, a second spring contact connector 42 adjacent to the first spring contact connector can be used to force a low or return current path, a third spring contact connector 43 adjacent to the second spring contact connector can be used to force a high current path, and a fourth spring contact connector 44 adjacent to the third spring contact connector can be used to force a low or return current path. In this example, the first (forced high) spring contact connector 41 can be electrically connected to a first set of conductive conduits in the PCB, wherein the first set may include one or more conductive conduits. The second (forced low or return) spring contact connector 42 can be electrically connected to a second set of conductive conduits in the PCB, wherein the second set may include one or more conductive conduits different from the first set. The third (forced high) spring contact connector 43 can be electrically connected to a third set of conductive conduits in the PCB, wherein the third set may include one or more conductive conduits different from the first and second sets. The fourth (forced low or return) spring connector 44 can be electrically connected to a fourth set of conductive conduits in the PCB, wherein the fourth set may include one or more conductive conduits that are different from the first, second and third sets of conductive conduits.

[0032] As shown in the figure, the coaxial cables 30 on each PCB are arranged in parallel, the PCBs are arranged in parallel to each other, and the spring clips 40 on each PCB are arranged in parallel. Additionally, the coaxial cable groups on each PCB (six coaxial cables in this example) are also parallel to each other. Furthermore, the spring clip connector groups on each PCB (four spring clip connectors in this example) are also parallel to each other. The use of such parallel connections provides support for high current levels, such as, but not limited to, currents exceeding 500 amperes (A), 1000A or greater, 2000A or greater, or 3000A or greater. The use of such parallel connections also provides support for low current levels, such as less than 500A, less than 5A, less than 1A, and currents entering or below the single-digit milliampere range. Furthermore, by alternating force and return paths within the insert 10, together with the use of coaxial cables, the inductance in the insert can be limited or reduced to, for example, 100 nanohenries (nH) to 60 nH or less. Multiple parallel paths are also used to limit or reduce the resistance in the insert.

[0033] In this respect, Figures 1 to 4In the example shown, a pulse current of 2000A can pass through insert 10. For example, a pulse current of 2000 amps can exist on both the forced and return paths, each passing through insert 10. In this case, there are 36 coaxial cables (six per PCB), each carrying a pulse current of 55A. There are six PCBs, each carrying a pulse current of 300A. There are 24 spring clip connectors, 12 of which are force connectors, each carrying a pulse current of 166.6A. Therefore, each coaxial cable carries a different portion of the pulse current compared to each PCB in the PCB and each spring clip connector; each spring clip connector carries a different portion of the current compared to each PCB in the PCB and each coaxial cable in the PCB; and each PCB in the PCB carries a different portion of the current compared to each PCB in the PCB and each spring clip connector. In some specific implementations, there can be different numbers of PCBs, different numbers of coaxial cables, and different numbers of spring clip connectors. For example, the number of spring contact connectors can be increased so that the current transmitted by each spring contact connector and each coaxial cable is equal. In some implementations, different PCBs may include different numbers of coaxial cable connectors and different numbers of spring contact connectors.

[0034] Coaxial cables, PCBs, and spring tabs can be configured and arranged to minimize the resistance and inductance of the insert assembly. For example, a computer program can be executed to simulate various configurations of the insert, and the configuration that produces the lowest resistance and inductance for a given current or current range can be selected. Coaxial cables, PCBs, and spring tabs can be configured and arranged to reduce the resistance and inductance of the insert assembly. For example, increasing the number of conductive paths while maintaining their parallelism can reduce these characteristics of the insert. Spring tabs can be configured and arranged to achieve target resistance and target inductance of the insert assembly. For example, specific resistance and inductance can be generated in the insert by selecting the number and arrangement of the insert components (e.g., PCB, coaxial connectors, and spring tabs).

[0035] In some embodiments, the insert 10 includes a shield 50 made of electrically insulating material. The shield 50 at least partially surrounds the spring assembly, particularly the area where a person might come into contact with the electrical conductor. In some embodiments, the shield 50 surrounds the entire spring assembly. In some embodiments, such as Figure 4 As shown, the shield 50 surrounds the side of the spring plate assembly and extends partially along the side of the PCB to cover any electrical connections that may be present along the side of the PCB.

[0036] In some implementations, insert 10 can be used to form a blind-mate connection with the gold or copper pads of a DIB or probe card, which holds the DUT to be tested by a test system such as an automated test equipment (ATE). For example, the blind-mate connection can be within the test head of the ATE. The blind-mate connector includes a self-aligning feature that guides the connector to the correct mating position. Connections to the gold or copper pads can be polarity-alternating, such that each positive connection is adjacent to each negative connection, thereby reducing inductance.

[0037] Reference Figure 5 An exemplary test system such as ATE 70 may include a current source 71, a polarity inverter 72, an insert 73 of the type described herein, and a DIB 74. In one example, for a pulse current of 2000A or greater, the insert may have an inductance of 100nH or less. In another example, for a current of 2000A or greater, the insert may have a resistance of 3 milliohms (mΩ) or less. In yet another example, for a pulse current of 2000A or greater, the insert may have an inductance of 500nH or less. In yet another example, for a pulse current of 2000A or greater, the insert may have a resistance of 10mΩ or less.

[0038] During operation, current flows from a current source through a polarity inverter 72, whose polarity remains the same or changes based on the requirements of the DUT (Distributed Under Test) connected to the test system. In some examples, the polarity inverter may be omitted. The current output from the polarity inverter is passed to an insert 73, which in this example includes an electrical and / or mechanical interface to a DIB 74. Current is passed from the polarity inverter 72 to the insert 73 via a coaxial cable (such as coaxial cable 30). The current from the insert is then passed to the DIB. As described above, the DIB holds the DUT in the test site 75 and distributes current from the insert 73 to the DUT in the test site. In some specific implementations, multiple inserts of the type described herein may be connected to a single DIB.

[0039] In some embodiments, the coaxial cables are each 13 meters or 13.5 meters long; however, different lengths may be used. For example, the coaxial cables may each have a length limited to three-digit meters or less; the coaxial cables may each have a length limited to two-digit meters or less; the coaxial cables may each have a length limited to one-digit meters or less; the coaxial cables may each have a length limited to one-digit decimeters or less; or the coaxial cables may each have a length limited to one-digit centimeters or less. In some embodiments, particularly those with a short distance between the insert and the current source, electrical conduits other than coaxial cables may be used.

[0040] ATE 70 also includes a control system 76. This control system may include a computing system comprising one or more microprocessors or other suitable processing devices as described herein. Communication between the control system and other components of ATE 70 is conceptually represented by line 77. DIB 74 includes a PCB having sites including mechanical and electrical interfaces to one or more DUTs being tested by or to be tested by the ATE. Power, including voltage, may be delivered to the DUTs connected to the DIB via one or more layers in the DIB. DIB 74 may also include one or more ground planes and one or more signal layers having vias for transmitting signals to the DUTs.

[0041] Site 75 may include pads, conductive traces, or other electrical and mechanical connection points to which the DUT can be connected. Test signals and response signals (including high-current signals) are transmitted between the DUT and the test instrument via test channels passing through the site. DIB74 may also include connectors, conductive traces, conductive layers, and circuitry for routing signals between the test instrument, the DUT connected to site 75, and other circuitry.

[0042] The control system 76 communicates with the test instrument (not shown) to control the test. The control system 76 can also be configured with a polarity inverter 72 to provide the voltage / current of the required polarity for the test. This control can be adaptive, as the polarity can be changed during the test if desired or required.

[0043] All or part of the test systems described in this specification, and their various modifications, may be configured or controlled at least in part by one or more computers, such as control system 76, using one or more computer programs tangibly embodied in one or more information carriers, such as one or more non-transitory machine-readable storage media. The computer programs may be written in any programming language, including compiled or interpreted languages, and may be deployed in any form, including as standalone programs or as modules, parts, subroutines, or other units suitable for a computing environment. The computer programs may be deployed to execute on a single computer, at a single site, or distributed across multiple sites interconnected via a network.

[0044] Actions associated with configuring or controlling the test system described herein may be performed by one or more programmable processors that execute one or more computer programs to control or perform all or some of the operations described herein. All or part of the test system and methods may be configured or controlled by dedicated logic circuitry (such as FPGAs (Field Programmable Gate Arrays) and / or ASICs (Application-Specific Integrated Circuits)) or by embedded microprocessors localized to the instrument hardware.

[0045] Processors suitable for executing computer programs include, for example, both general-purpose and special-purpose microprocessors, and any one or more processors in any kind of digital computer. Typically, a processor receives instructions and data from read-only memory or random access memory, or both. The components of a computer include one or more processors for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include (or be operatively coupled to receive data from or transfer data to, or both) one or more machine-readable storage media, such as mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks. Non-transitory machine-readable storage media suitable for embodying computer program instructions and data include all forms of non-volatile memory, including, for example, semiconductor memory devices such as EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), and flash memory devices; magnetic disks such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM (Optical Disc Read-Only Memory) and DVD-ROM (Digital Universal Optical Disc Read-Only Memory).

[0046] The elements of the different embodiments described may be combined to form other embodiments not specifically described above. Elements may be omitted from the previously described system without generally adversely affecting its operation or the operation of the system. Furthermore, individual elements may be combined into one or more single elements to perform the functions described in this specification.

[0047] Other specific embodiments not specifically described in this specification are also within the scope of the following claims.

Claims

1. An insert for a test system, the insert comprising: Coaxial cables, each of which is configured to deliver a first current originating from a current source; A printed circuit board (PCB), wherein each PCB is connected to a set of coaxial cables to receive the first current from each of the set of coaxial cables and to deliver the second current; and A spring sheet assembly comprising a plurality of spring sheets, each of the spring sheets being connected to a PCB to deliver a third current obtained from the PCB to a device interface board (DIB), the DIB being connected to a device under test (DUT) to be tested by the test system, each of the spring sheets having one of a plurality of polarities defined by the third current; The coaxial cables on each PCB are arranged in parallel, the PCBs are arranged in parallel, and the plurality of spring sheets on each PCB are arranged in parallel, wherein on each PCB, a set of the plurality of spring sheets is arranged such that adjacent spring sheets have different polarities.

2. The insert according to claim 1, wherein for a current of 2000 amperes (A) or greater, the insert has an inductance of 100 nanohenries (nH) or less.

3. The insert according to claim 1, wherein for a current of 2000 amperes (A) or greater, the insert has a resistance of 3 milliohms (mΩ) or less.

4. The insert according to claim 1, wherein for a current of 2000 amperes (A) or greater, the insert has an inductance of 500 nanohenries (nH) or less.

5. The insert according to claim 1, wherein for a current of 2000 amperes (A) or greater, the insert has a resistance of 10 milliohms (mΩ) or less.

6. The insert according to claim 1, wherein the first current is different from the second current.

7. The insert according to claim 1, wherein the second current is different from the third current.

8. The insert according to claim 1, wherein the first current is equal to the third current.

9. The insert according to claim 1, wherein the second current is different from the third current and the first current.

10. The insert of claim 1, wherein each coaxial cable includes a center conductor and a shield surrounding the center conductor, the shield including a loop for current transmitted through the center conductor, the shield and the center conductor achieving at least some inductance cancellation.

11. The insert of claim 1, wherein each coaxial cable includes a center conductor and a shield surrounding the center conductor and separated from the center conductor by a dielectric, the shield including a loop for current transmitted through the center conductor, wherein the thicknesses of the shield, the center conductor, and the dielectric are configured to maximize inductance cancellation.

12. The insert according to claim 1, further comprising: A protective cover made of electrically insulating material, the protective cover at least partially surrounding the spring plate assembly.

13. The insert according to claim 1, wherein the insert comprises a portion of a blind mating connector within the test head of the test system.

14. The insert according to claim 1, further comprising: Electrically insulating material separating each PCB in the PCB.

15. The insert of claim 1, wherein each PCB includes a surge suppressor to prevent voltage spikes or current spikes on the PCB.

16. The insert of claim 1, wherein the coaxial cable, the PCB, and the plurality of spring tabs are configured and arranged to achieve the target resistance and target inductance of the insert.

17. The insert of claim 1, wherein the insert is connected to a low-inductance copper pad on the DIB within an area of ​​2 inches (5.08 cm) by 3 inches (7.62 cm) or less.

18. A testing system, the testing system comprising: A device interface board (DIB) is used to connect to the device under test (DUT). and Test head, the test head including a blind mating connector to the DIB, the blind mating connector including an insert assembly, the insert assembly including: Coaxial cables, each of which is configured to deliver a first current originating from a current source; Printed circuit boards (PCBs), each PCB in which is connected to a set of coaxial cables to receive the first current from each of the coaxial cables in the set and to deliver the second current; and A spring sheet assembly comprising a plurality of spring sheets, each of the spring sheets being connected to a PCB to deliver a third current obtained from the PCB to the DIB, each of the spring sheets having one of a plurality of polarities defined by the third current; The coaxial cables on each PCB are arranged in parallel, the PCBs are arranged in parallel, and the multiple spring sheets on each PCB are arranged in parallel. On each PCB, a set of the plurality of spring sheets are arranged such that adjacent spring sheets have alternating polarities.

19. The test system of claim 18, wherein the coaxial cable has a length defined as two digits meters or less.

20. The test system of claim 18, wherein the coaxial cable has a length defined as a single-digit meter or less.

21. The test system of claim 18, wherein the coaxial cable has a length defined as a single decimeter or less.

22. The test system of claim 18, wherein the coaxial cable has a length defined as a few centimeters.

23. The test system of claim 18, wherein the coaxial cable, the PCB, and the plurality of spring sheets are configured and arranged to minimize the resistance and inductance of the insert assembly.

24. The test system of claim 18, wherein the coaxial cable, the PCB, and the plurality of spring sheets are configured and arranged to reduce the resistance and inductance of the insert assembly.

25. The test system of claim 18, wherein the coaxial cable, the PCB, and the plurality of spring sheets are configured and arranged to achieve the target resistance and target inductance of the insert assembly.

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