A reliability test platform and pin cushion device

Abstract

The application is directed to a reliability test platform scheme, which can meet the large current load and dynamic performance of the DC / DC conversion device, and most of the energy is fed back to the power grid through the load component, thereby reducing the energy loss. The structure layout of the test card is provided, the load component, the device under test and the connecting piece are arranged, and the loss on the energy transmission path is further reduced. The structure layout of the test pin pad is also provided, which not only meets the demand of large current output of the device under test, but also reduces the loss and working temperature on the test pin pad, and ensures the stable and reliable work of the test platform.

Description

Technical Field

[0001] This invention belongs to the field of high-frequency power supply technology, and particularly relates to a reliability testing platform and a pin pad device. Background Technology

[0002] Currently, VRM (Voltage Regulator Module) is generally used to power ultra-large-scale integrated circuit chips such as GPUs, CPUs, and DPUs. The VRM steps down the output voltage (>2V) of the intermediate bus converter (IBC) to the required supply voltage (<2V) of the chip. The reliability of the VRM is directly related to the reliability of the chip; therefore, the reliability testing of the VRM is a very critical part of the research and development and production process.

[0003] In VRM reliability testing, the VRM needs to operate under full load for several to several thousand hours, and the number of VRMs being tested simultaneously is enormous. Existing testing methods include two approaches: one uses a resistor as the VRM load, which consumes all electrical energy as heat, resulting in high energy consumption and demanding heat dissipation requirements, making it unsuitable for testing large numbers of VRMs; the other approach connects multiple VRMs in series as the input to an inverter, which feeds the VRM output back to the grid, making it more energy-efficient and environmentally friendly. However, implementing this method with multiple VRMs in series is costly, and when one VRM fails, the entire circuit ceases to function, making this method unsuitable for testing the lifespan distribution of VRMs.

[0004] Furthermore, during factory testing of VRMs or other power conversion devices, the product's appearance must be undamaged. Therefore, the product cannot be tested by soldering it to the substrate; it must be tested by placing the device under test on a probe test socket. As the output current of the device under test increases, the current-carrying capacity of the probe test needs to reach 50A or higher. Existing probe test sockets cannot meet this requirement, thus necessitating the development of a probe test socket with a simple structure, high current-carrying capacity, and low parasitic impedance. Summary of the Invention

[0005] In view of this, one of the objectives of the present invention is to provide a reliability testing platform, including a device under test, a low-voltage bus, and a load assembly; the device under test employs a step-down circuit, the input terminal of the device under test is electrically connected to the low-voltage bus, and the output terminal of the device under test is electrically connected to the input terminal of the load assembly; the output terminal of the load assembly is electrically connected to the low-voltage bus; the load assembly includes at least one boost circuit unit.

[0006] Preferably, the load component further includes a variable resistance load, which is used to simulate the dynamic changes in load current.

[0007] Preferably, the variable resistance load includes at least one resistor and at least one switch; the resistor and switch are connected in series and bridging the output terminals of the step-down circuit unit.

[0008] Preferably, the boost circuit unit includes a DC / DC boost circuit, the output of which is electrically connected to the low-voltage bus.

[0009] Preferably, it further includes a motherboard and a test substrate, wherein the device under test and the load assembly are disposed on the test substrate; the test substrate includes a connector, the test substrate is fixed on the motherboard, and is electrically connected to the motherboard through the connector.

[0010] Preferably, the test substrate further includes connection holes, through which the test substrate is fixed parallel to the motherboard; the connectors include power connectors and signal / auxiliary power connectors, all of which are disposed on the bottom surface of the test substrate; the device under test and the load assembly are disposed on the top surface of the test substrate.

[0011] Preferably, the connector is disposed on one side of the test substrate, and the test substrate is vertically fixed and electrically connected to the motherboard through the connector; the load assembly and the device under test are disposed on the top and / or bottom surface of the test substrate.

[0012] Preferably, the device under test is mounted on an adapter plate, the adapter plate includes an adapter connector, the adapter connector is disposed on one side of the adapter plate; the adapter plate is perpendicularly fixed to and electrically connected to the test substrate through the adapter connector.

[0013] Preferably, the adapter connector is a gold finger, and a slot is provided on the test substrate, with the gold finger inserted into the slot.

[0014] Preferably, the device under test is mounted on an adapter plate, the adapter plate includes an adapter connector disposed on the bottom surface of the adapter plate; the adapter plate is electrically connected to the test substrate through the adapter connector, and the adapter plate is arranged parallel to the test substrate.

[0015] Preferably, the adapter connector is a metal pin, and an adapter plate socket is provided on the test substrate, with the metal pin being inserted into the adapter plate socket.

[0016] Preferably, a heat sink is provided on the load component and / or the device under test, and the heat sink is fixed on the test substrate.

[0017] Preferably, the device under test is electrically connected to the test substrate by welding or by a probe test socket.

[0018] Preferably, it further includes a motherboard, a test card, a control card, and a transformer card. The device under test and the load component are mounted on the test card, and the test card, the control card, and the transformer card are all mounted on the motherboard. The transformer card adopts a DC / DC step-down circuit, and the output terminal of the transformer card is electrically connected to the low-voltage bus. The control card controls and / or monitors the transformer card, the device under test, and the load component.

[0019] Preferably, the transformer card, the control card, and the test card are all independent hardware units, and the transformer card, the control card, and the test card are fixed to the motherboard via connectors.

[0020] Preferably, a test cabinet interface is provided on the first side of the motherboard, the transformer card is disposed between the test cabinet interface and the control card, the control card is disposed in the middle of the motherboard, and the test card is disposed adjacent to the control card.

[0021] The present invention also provides a needle pad device, including a needle pad base plate, a needle pad cover plate, and a spring needle; the spring needle includes a needle cap, a spring, and a needle core; the needle core is fixed on the needle pad base plate, the spring is sleeved on the needle core, and the needle cap is sleeved on the upper end of the spring; one end of the needle core is used to fix and electrically connect to a test substrate; the needle cap is used to contact and electrically connect to a device under test; the needle pad cover plate is fixed to the needle pad base plate; the needle cap is exposed on the top surface of the needle pad cover plate.

[0022] Preferably, the pin pad device is soldered onto the test substrate in a patch manner, and the pin core having the same electrical network is electrically connected to the same pad on the test substrate.

[0023] Preferably, the pin pad base plate is a printed circuit or a ceramic substrate.

[0024] Preferably, the needle core is a metal block, which is welded to the needle pad base plate; the metal block is provided with a spring hole, and the spring and the needle cap are at least partially located in the spring hole.

[0025] Preferably, multiple spring holes are provided on the same metal block, and the needle cores in the multiple spring holes are electrically connected to the same electrical network.

[0026] The beneficial effects of this invention are:

[0027] This invention proposes a reliability testing platform that can meet the requirements of high current and dynamic performance of DC / DC converter loads, and feed most of the energy back to the power grid through load components, thereby reducing energy loss.

[0028] On the other hand, it provides a structural layout for the test card, and further reduces energy loss along the energy transmission path by setting up load components, the device under test, and connectors.

[0029] A test pin pad structure layout is also provided, which not only meets the high current output requirements of the device under test, but also reduces the loss and operating temperature on the test pin pad, ensuring the stable and reliable operation of the test platform. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figures 1 to 4 A solution for a reliability testing platform;

[0032] Figure 5 A to Figure 5 C represents a structural layout for the test card;

[0033] Figure 6 A and Figure 6 B represents another structural layout for the test card;

[0034] Figure 7 A and Figure 7 B represents another structural layout for the test card;

[0035] Figure 8 A to Figure 8 C represents another structural layout for the test card;

[0036] Figure 9 A structural layout for a reliability testing platform;

[0037] Figure 10 This is existing technology for spring needles;

[0038] Figures 11 to 13 This describes the structural layout of the needle pad device. Detailed Implementation

[0039] One of the core aspects of this invention is to provide a reliability testing platform and a needle pad device.

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] This invention proposes a scheme using a BOOST circuit as the load for VRM reliability testing; however, the reliability testing scheme disclosed in this invention is not only applicable to VRMs as devices under test, but can also be used to test other DC / DC converters. Figure 1 As shown, the input terminal of the device under test (DUT) and the output terminal of the load assembly 30 are both connected to the low-voltage bus 10. The output terminal 21 of the DUT 20 is connected to the input terminal of the load assembly 30, and most of the energy in the output power of the DUT 20 is fed back to the low-voltage bus 10 via the load assembly 30. The energy flow path and direction are as follows: Figure 1 As indicated by the gray arrow. Compared to using a resistor as a load, using a BOOST load as an energy recovery load can reduce losses along the energy transmission path by at least 80%.

[0042] Furthermore, the power of the load components can be increased by using multi-phase BOOST circuits connected in parallel, with at least one phase BOOST circuit serving as a load unit 31; when the load power needs to be expanded, this can be achieved by increasing the number of load units 31. For example... Figure 2 As shown, taking a two-phase BOOST circuit as an example as a load unit 31, the load assembly 30 includes three load units 31. The input terminals of all load units 31 are connected in parallel to the output terminal 21 of the device under test 20, and the output terminals of all load units 31 are connected in parallel to the low-voltage bus 10.

[0043] Furthermore, in some test scenarios requiring rapid changes in load current, using only a BOOST load may not be sufficient to achieve the required slope for the output current change of the device under test (DUT) 20. This slope can reach 1000 A / µs or even exceed 5000 A / µs. This invention adds a set of variable resistance loads 32, which includes at least one resistor and at least one switch, preferably a semiconductor power device. The resistor and switch are connected in series and then connected across the output terminals 21 of the DUT (i.e., the positive and negative output terminals). This variable resistance load can include multiple series branches of resistors and switches, and by setting different resistance values ​​and controlling different switch drive voltage amplitudes and slopes, the dynamic testing requirements of the load can be met.

[0044] To facilitate the maintenance and replacement of load components, the reliability testing platform adopts a modular design, such as... Figure 4 As shown. The reliability testing platform includes at least one test card 1, at least one control card 2, at least one transformer card 3, and a motherboard 4; Figure 4 The following description uses test cards 1a, 1b, and 1c, control cards 2a, 2b, and 2c, and transformer cards 3a, 3b, and 3c as examples. Transformer card 3 uses a DC / DC step-down circuit to convert high voltage (higher than the input voltage of the device under test 20) into the input voltage of the device under test 20. For devices under test with low input voltage, transformer card 3 can provide a more stable input voltage. Transformer card 3 is an independent hardware unit located adjacent to test card 1. Control card 2, as an independent hardware unit, is responsible for controlling and monitoring test card 1 and transformer card 3. External communication of this reliability testing platform can also be achieved through control card 2. The entire testing platform can include multiple control cards, each with different functions. Test card 1, control card 2, and transformer card 3 are fixed to the motherboard 4 via connectors.

[0045] This invention also discloses a structural layout of the test card, such as 5A to Figure 5 As shown in C. Figure 5 A is a top view diagram of the test card. Figure 5 B is a schematic diagram of the bottom view of the test card. Figure 5 C is a side view of the test card. In this embodiment, the test card is used for reliability testing of a single power supply product. The test card 1 includes a test substrate 50, pads or test socket probe contacts (hereinafter referred to as contacts) 51, mounting holes 52, a load assembly 30, a power connector 53, and a signal / auxiliary electrical connector 54. The test card 1 is fixed to the motherboard 4 (not shown) through the mounting holes 52, and the test substrate 50 is arranged parallel to the motherboard 4; the power connector 53 and the signal / auxiliary electrical connector 54 are disposed on the bottom surface of the test substrate 50, and the test card 1 is electrically connected to the motherboard 4 through the power connector 53 and the signal / auxiliary electrical connector 54. The device under test 20 can be directly soldered onto the pads, or a test socket with probes (not shown) can be mounted on the test substrate, and the device under test 20 is electrically connected to the test substrate 50 through the probes on the test socket.

[0046] Test card 1 also includes test socket mounting holes 56, device under test (DUT) heatsink mounting holes 55, load component heatsink mounting holes 58, and load component heatsink 57. The load component heatsink 57 is mounted on the top surface of the load component 30 and is fixed to the test substrate 50 via the load component heatsink mounting holes 58; the test socket is fixed to the test substrate 50 via the test socket mounting holes 56. A heatsink can be installed on the device under test (DUT) 20, and the heatsink is fixed to the test substrate 50 via the device under test heatsink mounting holes 55.

[0047] Optional, such as Figure 6 A and Figure 6 Figure B shows another structural layout of the test card. Figure 6 A is a top view diagram of the test card. Figure 6 B is a side view of the test card. The device under test (DUT) 20 is soldered to the test substrate 50 via pads 51. A heat sink is provided on the top surface of the DUT 20, and the heat sink is fixed to the test substrate 50 through the DUT heat dissipation holes 55. The load assembly 30 can be disposed on the top and / or bottom surface of the test substrate, and a load assembly heat sink 57 is provided on the top surface of the load assembly 30. The test card 1 is vertically disposed on the motherboard 4; the test card 1 is fixed to the motherboard 4 via gold fingers 59 or other types of connectors, and is electrically connected to the motherboard 4.

[0048] Optional, such as Figure 7 A and Figure 7 As shown in Figure B, the test card 1 can also be electrically connected to the motherboard 4 via a connector (not shown) and fixed to the motherboard 4 via a fixing hole 52; when the test card 1 is fixed to the motherboard 4, the test substrate 50 is arranged parallel to the motherboard. The device under test 20 is soldered to the adapter plate 60 via pads 51. A heat sink can be provided on the top surface of the device under test 20, and the heat sink is fixed to the adapter plate 60 via the heat sink mounting hole 55; the device under test 20 is fixed and electrically connected to the slot 61 provided on the test substrate 50 via gold fingers 59; the adapter plate 60 is vertically arranged on the test substrate 50.

[0049] Optional, such as Figure 8 A to Figure 8 Another structural layout of the test card shown in C; Figure 8 A is a top view diagram of test card 1. Figure 8 B is a top view of the adapter plate. Figure 8 C is a schematic diagram of the adapter board. The test card 1 is fixed parallel to the motherboard 4 through the fixing hole 52. The load assembly 30 and the adapter board socket 62 are disposed on the top surface of the test substrate 50. The device under test 20 is soldered to the adapter board 60 through the solder pad 51. A heat sink is disposed on the top surface of the device under test 20, and the heat sink is fixed to the adapter board through the heat sink mounting hole 55. Metal pins 63 are disposed on the bottom surface of the solder pad 51 (i.e., the bottom surface of the adapter board). The adapter board is fixed to the adapter board socket 62 through the metal pins 63, and the device under test 20 is electrically connected to the test substrate 50 through the metal pins 63.

[0050] The present invention also illustrates a structural layout of a reliability testing platform, such as... Figure 9As shown. The reliability testing platform adopts a modular design, including at least one test card 1, at least one control card 2, at least one transformer card 3, and a motherboard 4. In this embodiment, the reliability testing platform includes eight test cards 1a, 1b, 1c, 1d, 1e, 1f, 1g, and 1h, two control cards 2a and 2b, one transformer card 3, and a motherboard 4. Control cards 2a and 2b are located on the horizontal central axis of the motherboard (i.e., in the middle of the motherboard), and test cards 1a / 1b / 1e / 1f are respectively located adjacent to control card 2a. In this embodiment, four test cards 1a, 1b, 1e, and 1f are arranged in a 2x2 array, with control card 2a located in the middle of the 2x2 array; four test cards 1c, 1d, 1g, and 1h are arranged in a 2x2 array, with control card 2b located in the middle of the 2x2 array. The test cabinet interface 64 and handle 65 are respectively located adjacent to the first side 401 and the third side 403 of the motherboard. The transformer card 3 is located between the test cabinet interface 64 and the control card 2a. The structural layout of the test card can adopt the aforementioned implementation method, and the same technical effect can be obtained. The fixed connection method between the control card and the transformer card and the motherboard is not limited, and the fixed connection method between the test card and the motherboard can also be used.

[0051] In existing technologies, the core component of a probe test socket is a spring pin, and the electrical connection between the device under test (DUT) and the carrier plate is achieved through the spring pin. To increase the current-carrying capacity of the test socket, it is necessary to minimize the impedance of each probe and maximize the number of probes; both of these are problems that are difficult to solve in existing technologies. Figure 10 Taking a common structure of spring pins as an example, spring pin 70 includes a moving head 71, a stationary head 73, and a spring 72; the stationary head 73 is used for soldering and fixing to the test substrate 50; the moving head 71 is used for contacting the device under test. This structure is relatively complex. If the impedance is to be reduced, the spring pin needs to use more expensive materials such as gold and silver; and the manufacturing precision of the moving / stationary head needs to be improved to reduce the gap between them; in addition, a spring with stronger elasticity is needed to increase the contact pressure between the pin and the pad. Furthermore, given a fixed pad area of ​​the device under test, increasing the number of pins inevitably requires reducing the diameter of the pins and the spacing between the pins. This requires higher precision, mechanical strength, and conductivity for each component of the pin, and the insulating material fixing the pin position also needs to have higher strength.

[0052] This invention discloses a structure of a spring needle, such as Figure 11The diagram shows a direct-insertion probe test holder. The spring-loaded needle 80 includes a needle cap 81, a needle core 83, and a spring 82. The needle core 83 is fixed to the needle pad base plate 84, and the spring 82 is fitted onto one end of the needle core. The other end of the needle core is used for fixed electrical connection with the test substrate. The needle cap 81 is used for contact and electrical connection with the device under test. The needle cap 81 can move up and down via the spring 82, and at least one end of the needle cap 81 protrudes from the needle pad cover plate 85. Both the needle pad cover plate 85 and the needle pad base plate 84 are high-temperature resistant plastic parts, and they are joined together by adhesive or heating / melting. The spring-loaded needle 80, needle pad cover plate 85, and needle pad base plate 84 form a single unit, referred to as the needle pad 5. The needle pad 5 is connected to other structures of the test holder by screws 86. In use, the needle pad is first welded and fixed to the test substrate, and then other components are installed. One advantage of this design is its excellent heat dissipation, preventing a vicious cycle where high temperatures reduce spring force, leading to poor contact between the spring pin and the solder pad, further exacerbating the overheating of the spring pin and further reducing the spring force. Another advantage is the low contact resistance of the spring pin, as one end is directly soldered to the test substrate, eliminating contact resistance between the spring pin and the test board.

[0053] Optionally, the pin pad 5 can also be soldered onto the test substrate in a surface mount manner, such as... Figure 12 As shown, pins with the same electrical network are electrically connected to the same pad. In this embodiment, the pin pad base plate 84 can be a printed circuit board or a ceramic substrate.

[0054] Optional, such as Figure 13 As shown, the needle core is an integral structure, achieved by pre-setting a spring hole 87 in the copper block. The spring 82 is disposed within the spring hole 87, and the needle cap 81 is disposed on the upper end of the spring 82. The copper block is soldered onto the needle pad base plate 84. In this embodiment, the needle pad base plate 84 can be a printed circuit board or a ceramic substrate. The advantage of this embodiment is that the copper block has low resistance, further reducing the impedance of the spring needle; and by utilizing the thermal conductivity of copper, the operating temperature of the spring needle is further reduced, ensuring good working performance of the spring needle. The structural layout of the spring needle disclosed in this invention can be applied to the aforementioned test cards, and can achieve the corresponding technical effects.

[0055] The terms "equal to," "identical to," or "equal to" disclosed in this invention must take into account the parameter distribution of the engineering process, with an error distribution within ±30%. "Parallel" is defined as the angle between two line segments or lines being less than or equal to 45 degrees. "Perpendicular" is defined as the angle between two line segments or lines being within the range of [60, 120] degrees. The definition of "phase misalignment" also needs to consider the parameter distribution of the engineering process, with an error distribution of the phase misalignment degree within ±30%.

[0056] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A reliability testing platform, characterized in that, It includes a device under test, a low-voltage bus, and a load assembly; the device under test includes a step-down circuit unit, the input terminal of the device under test is electrically connected to the low-voltage bus, and the output terminal of the device under test is electrically connected to the input terminal of the load assembly; the output terminal of the load assembly is electrically connected to the low-voltage bus; the load assembly includes at least one step-up circuit unit.

2. The reliability testing platform according to claim 1, characterized in that, The load component also includes a variable resistance load, which is used to simulate the dynamic changes in load current.

3. The reliability testing platform according to claim 2, characterized in that, The variable resistive load includes at least one resistor and at least one switch; the resistor and switch are connected in series and bridging the output terminals of the step-down circuit unit.

4. The reliability testing platform according to claim 1, characterized in that, The boost circuit unit includes a DC / DC boost circuit, the output of which is electrically connected to the low-voltage bus.

5. The reliability testing platform according to claim 1, characterized in that, It also includes a motherboard and a test substrate, wherein the device under test and the load assembly are disposed on the test substrate; the test substrate includes a connector, the test substrate is fixed on the motherboard, and is electrically connected to the motherboard through the connector.

6. The reliability testing platform according to claim 5, characterized in that, The test substrate also includes connection holes, through which the test substrate is fixed parallel to the motherboard; the connectors include power connectors and signal / auxiliary power connectors, all of which are disposed on the bottom surface of the test substrate; the device under test and the load assembly are disposed on the top surface of the test substrate.

7. The reliability testing platform according to claim 5, characterized in that, The connector is disposed on one side of the test substrate, and the test substrate is vertically fixed and electrically connected to the motherboard through the connector; the load assembly and the device under test are disposed on the top and / or bottom surfaces of the test substrate.

8. The reliability testing platform according to claim 5, characterized in that, The device under test is mounted on an adapter plate, the adapter plate includes an adapter connector, the adapter connector is disposed on one side of the adapter plate; the adapter plate is perpendicularly fixed to and electrically connected to the test substrate through the adapter connector.

9. The reliability testing platform according to claim 8, characterized in that, The adapter connector is a gold finger, and a slot is provided on the test substrate, through which the gold finger is inserted.

10. The reliability testing platform according to claim 5, characterized in that, The device under test is mounted on an adapter plate, which includes an adapter connector disposed on the bottom surface of the adapter plate. The adapter plate is electrically connected to the test substrate through the adapter connector, and the adapter plate is arranged parallel to the test substrate.

11. The reliability testing platform according to claim 10, characterized in that, The adapter connector is a metal pin, and an adapter plate socket is provided on the test substrate. The metal pin is inserted into the adapter plate socket.

12. The reliability testing platform according to claim 5, characterized in that, A heat sink is provided on the load component and / or the device under test, and the heat sink is fixed on the test substrate.

13. The reliability testing platform according to claim 5, characterized in that, The device under test is electrically connected to the test substrate by welding or by a probe test socket.

14. The reliability testing platform according to claim 1, characterized in that, It also includes a motherboard, a test card, a control card, and a transformer card. The device under test and the load component are mounted on the test card, and the test card, the control card, and the transformer card are all mounted on the motherboard. The transformer card adopts a DC / DC step-down circuit, and the output terminal of the transformer card is electrically connected to the low-voltage bus. The control card controls and / or monitors the transformer card, the device under test, and the load component.

15. The reliability testing platform according to claim 14, characterized in that, The transformer card, the control card, and the test card are all independent hardware units, and the transformer card, the control card, and the test card are fixed to the motherboard via connectors.

16. The reliability testing platform according to claim 15, characterized in that, A test cabinet interface is provided on the first side of the motherboard, the transformer card is located between the test cabinet interface and the control card, the control card is located in the middle of the motherboard, and the test card is located adjacent to the control card.

17. A needle pad device, characterized in that, The device includes a needle pad base plate, a needle pad cover plate, and a spring needle. The spring needle includes a needle cap, a spring, and a needle core. The needle core is fixed to the needle pad base plate, the spring is sleeved on the needle core, and the needle cap is sleeved on the upper end of the spring. One end of the needle core is used to fix and electrically connect to a test substrate. The needle cap is used to contact and electrically connect to a device under test. The needle pad cover plate is fixed to the needle pad base plate. The needle cap is exposed on the top surface of the needle pad cover plate.

18. The needle pad device according to claim 17, characterized in that, The pin pad device is soldered onto the test substrate in a patch manner, and the pin core having the same electrical network is electrically connected to the same pad on the test substrate.

19. The needle pad device according to claim 18, characterized in that, The pin pad base plate is a printed circuit or a ceramic substrate.

20. The needle pad device according to claim 18, characterized in that, The needle core is a metal block, which is welded to the needle pad base plate; a spring hole is provided on the metal block, and the spring and the needle cap are at least partially located in the spring hole.

21. The needle pad device according to claim 20, characterized in that, Multiple spring holes are provided on the same metal block, and the needle cores in the multiple spring holes are electrically connected to the same electrical network.

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