Precise analog-to-digital converter testing device without bonding wire structure

Abstract

The invention relates to a precision analog-to-digital converter testing device without a bonding wire structure. The precision analog-to-digital converter testing device comprises a control board card, a digital function board card, a precision alternating current excitation board card, a precision direct current excitation board card, a mainboard and a testing platform which are integrally integrated, the test platform is in compression joint with the main board through the pure copper elastic firing pin to form bonding-wire-free connection; a thermal insulation material is arranged between the test platform and the device main body, and an openable windproof cover is arranged at the top. The device has the advantages of high integration, miniaturization, metering and calibration portability and the like, the influence of contact thermal electromotive force is eliminated by a unique bonding wire-free process and a temperature control structure of the device, the influence of temperature on a test result is small, and the test accuracy and reliability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic testing, and particularly to a precision analog-to-digital converter testing device with a wire-free structure. Background Art

[0002] High-precision analog-to-digital converters play an important role in many fields as key components of mixed-signal systems. Some analog chip manufacturers have currently launched a variety of ultra-high-resolution analog-to-digital converter chips with 24-bit or even 32-bit resolution. The core analog indicators such as integral nonlinearity, differential nonlinearity, signal-to-noise ratio, and harmonic distortion are close to the theoretical limit, and it is very difficult to test and verify these key indicator characteristics.

[0003] Currently, almost all high-precision analog-to-digital converters directly use an integrated circuit automatic test system (ATE), or build a dedicated precision test system based on the ATE system for mass production testing. The ATE system has complete digital and analog signal excitation and test modules for analog-to-digital converter testing. However, for the testing of high-precision ADC devices with more than 20 bits, the analog excitation source of the ATE system can no longer meet the requirements. Taking a certain type of 24-bit ADC as an example, its linearity index is better than 16 bits, and the signal source linearity index of the Teradyne J750 ATE system is also 16-bit linearity, which cannot meet the testing requirements of high-precision ADCs. Instead, a higher-precision external analog excitation source is used and integrated with the ATE system to jointly achieve chip testing.

[0004] Existing testing devices for high-precision ADC linear errors are almost all testing systems built based on a series of high-precision devices, and the testing process is completed through integrated software. The main disadvantages are as follows:

[0005] (1) Complex structure: The testing of high-precision analog-to-digital converters requires a standard signal excitation source and a voltmeter with extremely low noise and a very high linearity index. At the same time, ATE equipment is required to digitally configure the analog-to-digital converter chip to be tested, and a PC is networked with all devices to control the testing process, thus forming a set of testing devices. Since the testing process involves the transmission of a large number of precise analog signals and clock signals, the testing device contains a large number of coaxial cables and high-precision test lines, which are very inconvenient to disassemble and assemble, and are not conducive to the metrology and daily maintenance of the testing device.

[0006] (2) Test results are easily affected: The static index testing of high-precision analog-to-digital converters depends on a DC signal excitation source with a resolution reaching the microvolt level. The existing testing device applies the excitation signal to the chip to be tested through high-precision test lines and a chip testing platform. The testing link contains multiple connection nodes of different metals, such as Figure 1As shown, the measurement link contains 4 different metal connection points, namely the press contact point #1 between the connection wire and the excitation source, the soldering contact point #2 between the connection wire and the connector, the contact point #3 formed by the mating of the connectors, the soldering contact point #4 of the board-to-wire connector on the test platform, and the soldering contact point #5 between the chip under test and the PCB lead on the test platform. The contact thermoelectric potential between the solder and the copper wire is often in the order of dozens of microvolts and is significantly affected by temperature, generating a voltage error in the microvolt range and causing significant test errors. Summary of the Invention

[0007] To solve the above technical problems existing in the prior art, the object of the present invention is to provide a precision analog-to-digital converter test device with a wire-free structure, which can achieve high integration of the device, has the advantages of miniaturization, portability for metrological calibration, etc. The unique wire-free process and temperature control structure of the device eliminate the influence of contact thermoelectric potential, the test results are less affected by temperature, and the accuracy and reliability of the test are improved.

[0008] To achieve the above object of the invention, the present invention provides a precision analog-to-digital converter test device with a wire-free structure, including an integrated control board, a digital function board, a precision AC excitation board, a precision DC excitation board, a main board and a test platform;

[0009] The test platform is press-connected to the main board through pure copper elastic ejector pins to form a wire-free connection;

[0010] There is a heat insulation material between the test platform and the device body, and a windproof cover that can be opened and closed is configured on the top.

[0011] According to a technical solution of the present invention, the control board is used for the human-computer interaction of the test device and the interaction between the board card modules in the device, and executes the test process;

[0012] The digital function board is used to realize the digital functions of the integrated circuit automatic test system in the traditional test device;

[0013] The precision AC excitation board generates a standard AC voltage excitation with low noise and high purity, and is used for the analysis of the dynamic performance indicators of the analog-to-digital converter under test;

[0014] The precision DC excitation board generates a standard DC voltage excitation with low noise and high purity, and is used for the analysis of the static performance indicators of the analog-to-digital converter under test;

[0015] The main board is used to integrate all the board cards in the test device;

[0016] The test platform is used as the installation platform for the analog-to-digital converter under test.

[0017] According to a technical solution of the present invention, the digital function board is composed of a large-scale FPGA and a precision clock management circuit, and can generate digital patterns necessary for the analog-to-digital converter under test, collect and store data conversion results.

[0018] According to a technical solution of the present invention, the digital function board is inserted upside down on the top of the main board, and signal interaction is achieved through a high-speed board-to-board connector.

[0019] According to a technical solution of the present invention, the contact resistance of the pure copper elastic contact pin is less than 50 mΩ, and the elastic force range is 0.6 - 1.0 N.

[0020] According to a technical solution of the present invention, the heat insulation material is ceramic fiber, with a thickness of 10 - 50 mm and a thermal conductivity less than 0.03 W / m·K.

[0021] According to a technical solution of the present invention, the windproof cover is a semi-transparent structure, made of acrylic material, and the internal air flow velocity is less than 0.1 m / s when closed.

[0022] According to a technical solution of the present invention, the frequency range of the sine wave signal output by the precision AC excitation board is 0 - 100 kHz, and the total harmonic distortion THD is less than -125 dB;

[0023] The output voltage range of the precision DC excitation board is ±7V, and the resolution is 0.5 μV.

[0024] According to a technical solution of the present invention, the main board adopts a multi-layer PCB design, integrating high-speed signal traces and an independent power distribution network.

[0025] According to a technical solution of the present invention, the test platform fixes the elastic contact pin through a non-metallic pressing piece, and the pressing force is 0.5 - 1.2 g;

[0026] The test platform is built-in with a temperature sensor to monitor the contact temperature in real time and dynamically adjust the output of the excitation source through the control software.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention proposes a precision analog-to-digital converter test device with a wire-free structure. Through the improvement measures of the present invention, the test device can achieve high integration of the device, and has the advantages of miniaturization, portability for metrological calibration, etc. The unique wire-free process and temperature control structure of the device eliminate the influence of contact thermoelectric potential, and the test results are less affected by temperature, improving the accuracy and reliability of the test.

[0029] The integrated test device design of the present invention integrates the digital functional modules, analog signal excitation, and test platform necessary for the analog-to-digital converter test into one device. Each component is optimized in a partitioned manner, and a metrology calibration interface is reserved to facilitate the calibration of the metrological characteristics of the test device.

[0030] In the present invention, the connection between the test device and the analog-to-digital converter to be measured adopts a board-to-board press-fit method, without using wire bonding technology, ensuring that the signal transmission path from the precise analog signal excitation to the analog-to-digital converter to be measured only has contact points of the same type of metal, and the temperature-sensitive area is temperature-controlled to reduce the influence of contact thermoelectric potential. Brief Description of the Drawings

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 Schematically showing the signal transmission link of the existing test device (including 5 heterogeneous metal contacts);

[0033] Figure 2 Schematically showing the integrated structure diagram of the precision analog-to-digital converter test device with a wire-bonding-free structure in the embodiment of the present invention;

[0034] Figure 3 Schematically showing the partial detail diagram of the reverse insertion of the functional board and the press-fit of the elastic ejector pins in the embodiment of the present invention;

[0035] Figure 4 Schematically showing the signal transmission link in the embodiment of the present invention (only 2 copper contacts);

[0036] Figure 5 Schematically showing the heat insulation and windproof cover structure diagram of the test platform in an embodiment of the present invention. Detailed Embodiments

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0038] Such as Figure 2As shown in the figure, the present invention provides a precision analog-to-digital converter testing device with a wire-free structure, which includes an integrated control board 1, a digital function board 2, a precision AC excitation board 3, a precision DC excitation board 4, a main board 5 and a testing platform 6; the control board 1 is used for the human-computer interaction of the testing device and the interaction between various board modules in the device, and executes the testing process;

[0039] The testing platform 6 is press-connected to the main board 5 through pure copper elastic contact pins to form a wire-free connection. With this wire-free process connection method, the transmission path of the precision analog excitation signal to the device under test is as Figure 4 shown;

[0040] As Figure 5 shown, a heat insulation material is provided between the testing platform 6 and the device main body to block the heat conduction from the heat source in the device to the testing platform 6. A windproof cover that can be opened and closed, such as a flip-type windproof cover, is configured at the top to block the turbulent flow formed by the surrounding air flow and avoid the deterioration of the signal quality due to the formation of a temperature gradient on the testing excitation signal transmission path.

[0041] Adopting an integrated testing device design, integrating the necessary digital function modules, analog signal excitation, and testing platform 6 for analog-to-digital converter testing into one device, optimizing the design of each component part by part, and reserving a metrological calibration interface to facilitate the calibration of the metrological characteristics of the testing device.

[0042] The connection between the testing device and the device under test analog-to-digital converter adopts a board-to-board press connection method without using a wire bonding process, ensuring that the signal transmission path from the precision analog signal excitation to the device under test analog-to-digital converter only has contact points of the same type of metal, and controlling the temperature of the temperature-sensitive area to reduce the influence of contact thermoelectric potential.

[0043] The precision analog-to-digital converter testing device with a wire-free structure proposed by the present invention can achieve high integration of the device, has the advantages of miniaturization, portability for metrological calibration, etc. The unique wire-free process and temperature control structure of the device eliminate the influence of contact thermoelectric potential, and the test results are less affected by temperature.

[0044] In some embodiments of the present invention, the digital function board 2 is used to implement the digital functions of the integrated circuit automatic test system in the traditional testing device;

[0045] The precision AC excitation board 3 generates a standard AC voltage excitation with low noise and high purity for the analysis of the dynamic performance indicators of the device under test analog-to-digital converter;

[0046] The precision DC excitation board 4 generates a standard DC voltage excitation with low noise and high purity for the analysis of the static performance indicators of the device under test analog-to-digital converter;

[0047] The main board 5 is used to integrate all the boards in the testing device;

[0048] The test platform 6 is used as the installation platform for the analog-to-digital converter under test.

[0049] Through the integrated control board 1, digital function board 2, AC / DC excitation board, main board 5 and test platform 6, and by making the test platform 6 form a wire-free connection with the main board 5 through a pure copper elastic punch pin, and setting heat insulation materials between the test platform 6 and the device body and configuring a wind shield at the top, the problems of "complex structure and difficult disassembly and maintenance" caused by the combination of multiple devices and a large number of cable connections in the existing test device are solved, and the miniaturization and portability of the device are realized; at the same time, the thermoelectric potential interference is reduced, the number of metal contacts is reduced from 5 to 2, and the contact thermoelectric potential error is reduced to less than the microvolt level; the temperature stability is enhanced, and the technical effects of suppressing internal heat conduction and external air disturbance and reducing the influence of temperature gradient on signal transmission are achieved.

[0050] In some embodiments of the present invention, the digital function board 2 is composed of a large-scale FPGA and a precision clock management circuit, and can generate the digital code patterns necessary for the analog-to-digital converter under test, collect and store the data conversion results.

[0051] As Figure 3 shown, each function board is inserted upside down on the plane of the main board 5 at the top of the device. The main board 5 is in direct contact with the test platform 6 carrying the chip through a pure copper elastic punch pin, and the test platform 6 is fastened by a non-metallic pressing piece after being installed on the punch pin.

[0052] In some embodiments of the present invention, the digital function board 2 is inserted upside down on the top of the main board 5, and signal interaction is realized through a high-speed board-to-board connector.

[0053] Through the upside-down installation and board-to-board connection, the signal transmission path is shortened, signal delay and attenuation are reduced, the response speed of the digital function module is optimized, and the generation and data acquisition of complex code patterns for high-precision ADC are supported.

[0054] In some embodiments of the present invention, the contact resistance of the pure copper elastic punch pin is less than 50 mΩ, and the elastic force range is 0.6 - 1.0 N.

[0055] By defining the contact resistance and elastic force range of the elastic punch pin, the mechanical stability and electrical performance of the crimp connection are ensured, the problems of "easy loosening of the contacts in the wire bonding process and fluctuation of the contact thermoelectric potential" are solved, and long-term reliable signal transmission is realized.

[0056] In some embodiments of the present invention, the heat insulation material is ceramic fiber, the thickness is 10 - 50 mm, and the thermal conductivity is less than 0.03 W / m·K.

[0057] Through the low-thermal-conductivity ceramic fiber thermal insulation layer, the heat conduction from the internal heat sources of the device (such as the main board 5 and the functional board cards) to the test platform 6 is blocked, and the temperature fluctuation of the test platform 6 is controlled within ±0.1°C, solving the core problem of "the contact thermoelectric potential is affected by temperature".

[0058] In some embodiments of the present invention, the wind shield is a semi-transparent structure, made of acrylic material, and the internal air flow velocity is less than 0.1 m / s when closed.

[0059] The air flow is suppressed by the wind shield to avoid the temperature gradient caused by the external air flow, further stabilizing the test environment, ensuring that the microvolt-level excitation signal is not affected by the environment, and improving the test accuracy of the static index.

[0060] In some embodiments of the present invention, the frequency range of the sine wave signal output by the precision AC excitation board card 3 is 0 to 100 kHz, and the total harmonic distortion THD is less than -125 dB;

[0061] The output voltage range of the precision DC excitation board card 4 is ±7V, and the resolution is 0.5 μV.

[0062] Through the design of high-purity AC excitation signals, the problem that harmonic distortion affects the signal-to-noise ratio in the dynamic test of high-precision ADCs is solved, meeting the dynamic performance verification requirements of 24-bit and above ADCs; through the microvolt-level resolution DC excitation source, the problem of "integral nonlinear test error" caused by insufficient accuracy of the existing excitation source is solved, and the accurate measurement of the static characteristics of high-precision ADCs is realized.

[0063] In some embodiments of the present invention, the main board 5 adopts a multi-layer PCB design, integrating high-speed signal traces and an independent power distribution network.

[0064] Through the multi-layer PCB and independent power supply design, the crosstalk of digital signals to the analog excitation source is reduced, the signal integrity is optimized, and the problem of "noise introduced by complex wiring" is solved.

[0065] In some embodiments of the present invention, the test platform 6 fixes the elastic ejector pin through a non-metallic pressing piece, and the pressing force is 0.5 to 1.2 g;

[0066] The test platform 6 is internally provided with a temperature sensor to monitor the contact temperature in real time and dynamically adjust the output of the excitation source through the control software.

[0067] By precisely controlling the pressing force with a non-metallic pressing piece, the contact failure caused by the thermal expansion and contraction of the metal material is avoided, ensuring the long-term stability of the crimp connection, and solving the problem that the contact points of the test link are easily affected by temperature; through the temperature closed-loop control, the temperature drift error of the contact thermoelectric potential is dynamically compensated, further reducing the test error to the sub-microvolt level, and improving the adaptability of the device and the consistency of the test results.

[0068] The parts not elaborated in the present invention belong to the well-known technologies in the art.

[0069] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0070] The various embodiments in this specification are described in a progressive manner, with each embodiment highlighting the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0071] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A precision analog-to-digital converter test device with a wire-bondless structure, characterized in that, Including integrated control board, digital function board, precision AC excitation board, precision DC excitation board, main board and test platform; The test platform is crimped to the mainboard via a pure copper elastic striker to form a solderless connection; A heat-insulating material is provided between the test platform and the device body, and an openable and closable windproof cover is arranged on the top.

2. The precision analog-to-digital converter testing device with a wire-free structure according to claim 1, wherein The control board is used for human-computer interaction of the test device and interaction between the board modules in the device to execute the test process; The digital function board is used to realize the digital functions of the integrated circuit automatic test system in the traditional test device; The precision AC excitation board generates low-noise, high-purity standard AC voltage excitation for dynamic performance index analysis of the analog-to-digital converter under test; The precision DC excitation board generates low-noise, high-purity standard DC voltage excitation for static performance index analysis of the analog-to-digital converter under test; The mainboard is used to integrate all boards into the test device; The test platform is used as a mounting platform for the analog-to-digital converter under test.

3. The precision analog-to-digital converter testing device with a wire-free structure according to claim 2, wherein, The digital function board is composed of a large-scale FPGA and a precision clock management circuit, and can generate the digital code pattern required by the analog-to-digital converter under test, and collect and store data conversion results.

4. The precision analog-to-digital converter testing device with a wire-free structure according to claim 1, characterized in that, The digital function board is inserted upside down on the top of the main board, and signal interaction is achieved through a high-speed board-to-board connector.

5. The precision analog-to-digital converter testing device with a wire-bondless structure according to claim 1, wherein, The contact resistance of the pure copper elastic striker is less than 50mΩ, and the elastic force range is 0.6-1.0N.

6. The precision analog-to-digital converter testing device with a wire-bondless structure according to claim 1, wherein The heat insulating material is ceramic fiber, has a thickness of 10 to 50 mm, and a thermal conductivity coefficient of less than 0.03 W / m·K.

7. The precision analog-to-digital converter testing device with a wire-free structure according to claim 1, wherein The windshield is a translucent structure made of acrylic material, and the internal air flow rate is less than 0.1m / s when closed.

8. The precision analog-to-digital converter testing device with a wire-free structure according to claim 1, characterized in that, The sine wave signal frequency range output by the precision AC excitation board is 0-100kHz, and the total harmonic distortion THD is less than -125dB; The output voltage range of the precision DC excitation board is ±7V, and the resolution is 0.5μV.

9. The precision analog-to-digital converter testing device with a wire-free structure according to claim 1, wherein The motherboard adopts a multi-layer PCB design, integrating high-speed signal routing and an independent power distribution network.

10. The precision analog-to-digital converter testing device with a wire-bondless structure according to claim 1, wherein The test platform fixes the elastic striker through a non-metallic pressing piece with a pressing force of 0.5 to 1.2 g; The test platform has a built-in temperature sensor to monitor the contact temperature in real time and dynamically adjust the excitation source output through control software.

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