Calibration method and system for ATE (automatic test equipment)

Abstract

The invention discloses a calibration method and system of ATE test equipment. The calibration method comprises the steps of obtaining calibration data, performing self-compensation and measuring and calibrating a tested single board through a calibration device. The step of obtaining the calibration data comprises the steps of selecting one FPGA from the to-be-tested single boards as a calibration source, calibrating and calibrating the calibration source, calibrating the to-be-tested single board where the calibration source is located as a calibration device through the calibration source, and taking time delay data between a calibration device signal and a calibration source signal as the calibration data. The self-compensation comprises the following steps: compensating the signal delay of the calibration device according to the calibration data, and ensuring that the calibration device provides a reference synchronization signal for the tested single board. The FPGA is adopted as a calibration source, calibration of the test equipment can be completed without an external TDC calibration board, the limitation of the number of channels of a traditional TDC calibration board is broken through, and the accuracy and reliability of a calibration result are also improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor automatic test equipment, and particularly to a calibration method and system for ATE test equipment. Background Art

[0002] In ATE (Automatic Test Equipment) devices, when performing AC (Alternating Current) calibration, it is usually dependent on an external TDC (Time-to-Digital Converter) calibration board to accurately measure the delay between channels. However, this method has some significant limitations.

[0003] Firstly, due to hardware design limitations, the number of channels supported by the TDC calibration board is limited. This is insufficient when facing a single board that requires calibration of more channels, and it also limits its adaptability and flexibility in different test environments and requirements, making it difficult to quickly adjust test parameters or adapt to new test requirements.

[0004] Secondly, in the case where the requirements for AC calibration accuracy are not strict, using a high-precision TDC chip not only increases unnecessary hardware costs but also fails to fully utilize its performance, resulting in a waste of resources.

[0005] In addition, during use, a complex correspondence relationship between the single-board channels and the TDC channels needs to be added at the software level, which increases the difficulty of software development and maintenance and also raises the risk of errors. Summary of the Invention

[0006] The purpose of the present invention is to provide a calibration method and system for ATE test equipment, which can accurately measure the sending and receiving directions of a multi-channel single board, reduce the dependence on TDC equipment, and improve the efficiency and flexibility of the test process.

[0007] To solve the above technical problems, the present invention provides a calibration method and system for ATE test equipment. The calibration method includes the following steps:

[0008] Obtain calibration data. Select an FPGA from the single board to be tested as a calibration source, calibrate and calibrate the calibration source; use the calibration source to calibrate the single board where it is located as a calibration device, and use the delay data between the signal of the calibration device and the signal of the calibration source as calibration data;

[0009] Self-compensation. Compensate the signal delay of the calibration device itself according to the calibration data to ensure that the calibration device provides a reference synchronization signal to the single board under test;

[0010] Measure and calibrate the DUT (Device Under Test) through the calibration device.

[0011] Furthermore, the calibration data includes calibration data in the transmission direction of the calibration device and calibration data in the reception direction. The acquisition of the calibration data includes the following steps:

[0012] Acquire the calibration data in the transmission direction of the calibration device: Use an oscilloscope to measure the square wave signal output by the output channel of the calibration source and the square wave signal of the output channel of the calibration device, compare and record the delay between the square wave signal of the output channel of the calibration source and the square wave signal output by the output channel of the calibration source, and obtain the calibration data in the transmission direction;

[0013] Acquire the calibration data in the reception direction of the calibration device: The input channel of the calibration device receives the reference synchronization signal from its own output and delivers the signal to the input channel of the calibration source. Use an oscilloscope to measure the signal of the input channel of the calibration source and the reference synchronization signal, compare and record the delay between the signal of the input channel of the calibration source and the reference synchronization signal, and obtain the calibration data in the reception direction.

[0014] Furthermore, the method for obtaining the calibration data in the reception direction of the calibration device includes:

[0015] Divide the channels in the calibration device into odd channels and even channels, and use a loopback cable to connect the odd channels and the even channels;

[0016] When the even channels are used as the output channels and the odd channels are used as the input channels, use the square wave signal output by the calibration source to be delivered to the odd channels through the even channels, and record the delay data of the odd channels relative to the even channels to obtain the calibration data in the reception direction of the odd channels;

[0017] When the odd channels are used as the output channels and the even channels are used as the input channels, use the square wave signal output by the calibration source to be delivered to the even channels through the odd channels, and record the delay data of the odd channels relative to the even channels to obtain the calibration data in the reception direction of the even channels;

[0018] Use the calibration data in the reception direction of the odd channels and the even channels as the calibration data in the reception direction.

[0019] Furthermore, the steps of measuring and calibrating the DUT through the calibration device include:

[0020] Measurement and calibration of the receiving direction of the DUT board: The calibration device sends a reference synchronization signal to the DUT board, and the DUT board receives and measures the time when the reference synchronization signal arrives at the DUT board to obtain the first raw measurement data; the first raw measurement data is compared with the calibration data of the sending direction of the calibration device to obtain the receiving direction delay difference of the DUT board, and the receiving direction delay difference of the DUT board is compensated to the receiving direction of the DUT board.

[0021] Measurement and calibration of the sending direction of the DUT board: The calibration device collects the square wave signals sent by each channel of the DUT board to the calibration device and measures the trigger time of the rising edge or falling edge of each channel's square wave signal to obtain the second raw measurement data; after uniformly processing the second raw measurement data of each channel, the delay difference of the sending direction of the DUT board is obtained, and the delay difference is compensated to the sending direction of the DUT board.

[0022] A calibration system for an ATE test device, including a calibration device;

[0023] The calibration device includes a calibration source, a waveform modulation unit, and a data processing unit;

[0024] The waveform modulation unit is bidirectionally connected to the calibration source, and the data processing unit is respectively connected to the calibration source and the waveform modulation unit;

[0025] Wherein, the calibration device is connected to multiple channels of the DUT board through signal lines of the same length, and the calibration source is used to provide a calibration signal to the DUT board and collect the response signal of the DUT board.

[0026] Further, the calibration source includes two parallel first signal paths and second signal paths, and both the first signal path and the second signal path include a fractional delay unit and an integer delay unit connected in sequence.

[0027] Further, the first signal path is the receiving direction, and the input end is connected to the output end of the waveform modulation unit for receiving and measuring the arrival time of the DUT board signal.

[0028] Further, the second signal path is the sending direction, and the output end is connected to the input end of the first waveform modulation unit for sending a signal to the DUT board.

[0029] Further, the waveform modulation unit includes a comparator, and the comparator is connected to the integer delay unit of the first signal path.

[0030] Further, the calibration device further includes a connector, and the connector has multiple channels and is connected to the waveform modulation unit.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] By using an FPGA as a calibration source, the present invention can complete the calibration of the test equipment without an external TDC calibration board, breaking through the channel number limitation of the traditional TDC calibration board; the design of the signal path combined with the adjustment function of the waveform modulation unit can precisely control the sending and receiving of signals, realizing efficient two-way calibration and ensuring the accuracy and reliability of the calibration results. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a block diagram of the calibration method in an embodiment of the present invention;

[0034] Figure 2 is a schematic structural diagram of the calibration system in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The calibration method and system of an ATE test equipment of the present invention will be described in more detail below with reference to the schematic diagrams, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the beneficial effects of the present invention. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the present invention.

[0036] In the following paragraphs, the present invention will be described more specifically by way of example with reference to the accompanying drawings. The advantages and features of the present invention will be clearer according to the following description. It should be noted that the drawings are all in a very simplified form and use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the embodiments of the present invention.

[0037] Embodiment 1

[0038] As Figure 1 shown, this embodiment proposes a calibration method for an ATE test equipment, and the calibration method includes the following steps:

[0039] Obtain calibration data, select an FPGA from the single board under test as a calibration source, calibrate and calibrate the calibration source; calibrate the single board under test where the calibration source is located as a calibration device through the calibration source, and use the delay data between the calibration device signal and the calibration source signal as calibration data. Using the same device as the single board under test can avoid the problem of channel mismatch and facilitate the normal operation of the ATE test equipment. The calibration data is the basis for signal delay compensation in the subsequent calibration process, thus ensuring the accuracy of the calibration process.

[0040] Self-compensation, compensating for the signal delay of the calibration device itself according to the calibration data, eliminating or reducing the error introduced by the calibration device during signal transmission, enabling the calibration device to provide a reference synchronization signal to the device under test, thereby achieving high-precision calibration.

[0041] Measure and calibrate the device under test through the calibration device, thereby improving the accuracy and reliability of calibration.

[0042] The above calibration method does not require an external TDC calibration board. Only through precise calibration and self-compensation can the calibration device provide a reliable reference synchronization signal, making the delay calibration of the transmission and reception directions of the device under test more accurate. This not only improves the accuracy and reliability of calibration, but also simplifies the calibration process, reduces costs, and enhances the performance of the ATE test equipment and the credibility of test results.

[0043] It should be noted that when using the calibration source, a clock signal generation board (i.e., a BUFFER board) or an oscilloscope can be used to calibrate the calibration source.

[0044] In this embodiment, the calibration data includes calibration data in the transmission direction and calibration data in the reception direction of the calibration device. The acquisition of the calibration data includes the following steps:

[0045] Obtain the calibration data in the transmission direction of the calibration device: Use an oscilloscope to measure the square wave signal output by the output channel of the calibration source and the square wave signal of the output channel of the calibration device, compare and record the delay between the square wave signal of the output channel of the calibration source and the square wave signal output by the output channel of the calibration source, and obtain the calibration data in the transmission direction, so that the calibration source can provide an accurate time reference in the transmission direction, making the subsequent delay measurement in the transmission direction more accurate.

[0046] Obtain the calibration data in the reception direction of the calibration device: The input channel of the calibration device receives the reference synchronization signal from its own output and delivers the signal to the input channel of the calibration source. Use an oscilloscope to measure the signal of the input channel of the calibration source and the reference synchronization signal, compare and record the delay between the signal of the input channel of the calibration source and the reference synchronization signal, and obtain the calibration data in the reception direction, so that the calibration source can also provide an accurate signal in the reception direction, making the delay measurement in the reception direction equally accurate.

[0047] The acquisition of the calibration data improves the accuracy of the calibration data by precisely measuring and recording the delays in the transmission and reception directions, thereby improving the accuracy of the entire calibration process.

[0048] Furthermore, the method for obtaining the calibration data in the reception direction of the calibration device includes:

[0049] Divide the channels in the calibration device into odd channels and even channels, and use a loopback line (i.e., a CABLE line) to connect the odd channels and the even channels, so that each channel of the calibration device can be evenly calibrated, which helps to identify and compensate for possible differences between channels, ensures that the receiving directions of all channels can reach the same calibration accuracy, and thus improves the systematicness and comprehensiveness of the calibration process.

[0050] When the even channels are used as output channels and the odd channels are used as input channels, the square wave signal output by the calibration source is transmitted through the even channels to the odd channels, and the delay data of the odd channels relative to the even channels is recorded to obtain the calibration data of the receiving direction of the odd channels, which helps to accurately measure and compensate the signal delay of the odd channels in the receiving direction, making the calibration accuracy of the odd channels higher.

[0051] When the odd channels are used as output channels and the even channels are used as input channels, the square wave signal output by the calibration source is transmitted through the odd channels to the even channels, and the delay data of the odd channels relative to the even channels is recorded to obtain the calibration data of the receiving direction of the even channels, which helps to accurately measure and compensate the signal delay of the even channels in the receiving direction, making the calibration accuracy of the even channels higher.

[0052] Taking the calibration data of the receiving directions of the odd channels and the even channels as the calibration data of the receiving direction, a comprehensive calibration data of the receiving direction can be obtained, which helps to more accurately calibrate the receiving direction of the entire calibration device and improve the overall accuracy and reliability of the calibration.

[0053] This process of separately calibrating the odd channels and the even channels enables all channels to be evenly tested and calibrated, can more accurately compensate for the signal delay in the receiving direction, and thus improves the calibration accuracy.

[0054] In this embodiment, the steps of measuring and calibrating the DUT (Device Under Test) by the calibration device include:

[0055] Measurement and calibration of the receiving direction of the DUT: The calibration device sends a reference synchronization signal to the DUT, and the DUT receives and measures the time when the reference synchronization signal arrives at the DUT to obtain the first raw measurement data; compare the first raw measurement data with the calibration data of the sending direction of the calibration device to eliminate the influence during the transmission process, more accurately obtain the receiving direction delay difference of the DUT, and compensate the receiving direction delay difference of the DUT to the receiving direction of the DUT, so that the receiving direction of the DUT is calibrated.

[0056] Measurement and calibration of the transmission direction of the DUT board: The calibration device collects the square wave signals sent by each channel of the DUT board to the calibration device, measures the trigger time of the rising edge or falling edge of the square wave signal of each channel, and obtains the second original measurement data; after uniformly processing the second original measurement data of each channel, the time delay difference of the transmission direction of the DUT board is obtained, and the time delay difference is compensated to the transmission direction of the DUT board, so that the transmission direction of the DUT board is calibrated.

[0057] The calibration device can provide an accurate time reference. By using the calibration device to measure and calibrate the DUT board without relying on external measurement equipment, it can adapt to different test requirements and configurations, enhancing the flexibility and adaptability of the ATE test equipment.

[0058] Embodiment 2

[0059] As Figure 2 shown, this embodiment proposes a calibration system for an ATE test equipment, including using one of multiple DUT boards as a calibration device, and the calibration device is used to measure the remaining DUT boards. Specifically, Figure 2 The corresponding Chinese names of the English abbreviations involved are as follows: DLY - fractional delay unit, INTER - integer delay unit, Cmp - receiving direction, DRV - transmission direction, CPU - data processing unit, PE - waveform modulation unit, and Mvp - measurement point.

[0060] In this embodiment, the calibration device includes a calibration source, a waveform modulation unit, and a data processing unit.

[0061] The calibration source, as a generator of calibration signals, is used to provide calibration signals to the DUT board and collect the response signals of the DUT board.

[0062] The waveform modulation unit is bidirectionally connected to the calibration source and is used to adjust the voltage magnitude, configure the voltage mode of the output channel, and set the comparator threshold voltage. The waveform modulation unit can precisely control the waveform of the signal and can adapt to different test conditions, thereby improving the calibration accuracy and signal quality.

[0063] The data processing unit is respectively connected to the calibration source and the waveform modulation unit and is used to configure signal parameters, process the collected data, and store the calibration results, ensuring the accuracy and reliability of the calibration results and providing necessary data support for subsequent tests and analyses.

[0064] Among them, the calibration device is connected to multiple channels of the DUT (Device Under Test) through signal lines of the same length. By using an FPGA on the DUT as a calibration source to measure and calibrate other boards, the device has higher flexibility and programmability, allowing it to quickly adapt to different test requirements and configurations, reducing the dependence on external expensive equipment, and helping to reduce the calibration cost.

[0065] In this embodiment, the calibration source includes two parallel first signal paths and second signal paths, so that calibration in different directions can be processed simultaneously, improving the efficiency of the calibration process. Both the first signal path and the second signal path include a fractional delay unit and an integer delay unit connected in sequence. The fractional delay unit and the integer delay unit are used in cooperation to provide high-precision signal delay to simulate the delay situation that the signal may encounter in the actual transmission process, ensuring the synchronization and accuracy of the signal during the calibration process, and thus improving the reliability of the calibration result.

[0066] Further, the first signal path is the receiving direction, i.e., the Cmp direction, and its input end is connected to the output end of the waveform modulation unit, for receiving and measuring the arrival time of the rising edge or falling edge of the DUT signal. In the receiving direction, the fractional delay unit and the integer delay unit help the calibration device simulate the receiving delay of the signal, so as to accurately measure the arrival time of the rising edge or falling edge of the signal.

[0067] The second signal path is the transmitting direction, i.e., the DRV direction, and its output end is connected to the input end of the first waveform modulation unit, for sending a square wave signal with a configurable frequency to the DUT. While meeting different test conditions, it can also calibrate the delay in the transmitting direction. In the transmitting direction, the fractional delay unit and the integer delay unit make the transmitted square wave signal have the required delay characteristics.

[0068] In this embodiment, the waveform modulation unit includes a comparator, and the comparator is connected to the integer delay unit of the first signal path, so that the comparator can accurately capture the edge change of the signal, thereby improving the calibration accuracy in the receiving direction or the transmitting direction.

[0069] In this embodiment, the calibration device further includes a connector, and the connector has multiple channels and is connected to the waveform modulation unit, enabling the calibration process to perform precise operations on multiple signal channels simultaneously, thus significantly improving the calibration efficiency and enhancing the reliability of signal transmission.

[0070] In summary, by using an FPGA as the calibration source, the present invention can complete the calibration of the test equipment without externally connecting a TDC calibration board, breaking through the channel number limitation of the traditional TDC calibration board; the design of the signal path combined with the voltage regulation function of the waveform modulation unit can precisely control the sending and receiving of signals, achieving efficient two-way calibration and ensuring the accuracy and reliability of the calibration results.

[0071] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A calibration method for an ATE test device, characterized in that, Including the following steps: Obtain calibration data, select an FPGA from the single board to be tested as a calibration source, and calibrate and calibrate the calibration source; Use the calibration source to calibrate the single board to be tested where it is located as a calibration device, and use the delay data between the signal of the calibration device and the signal of the calibration source as calibration data; Self-compensation, compensate the signal delay of the calibration device itself according to the calibration data to ensure that the calibration device provides a reference synchronization signal to the single board under test; Measure and calibrate the single board under test through the calibration device.

2. The calibration method of the ATE test equipment according to claim 1, characterized in that, The calibration data includes calibration data in the transmission direction of the calibration device and calibration data in the reception direction. The acquisition of the calibration data includes the following steps: Obtain the calibration data in the transmission direction of the calibration device: Use an oscilloscope to measure the square wave signal output by the output channel of the calibration source and the square wave signal of the output channel of the calibration device, compare and record the delay between the square wave signal of the output channel of the calibration source and the square wave signal output by the output channel of the calibration source, and obtain the calibration data in the transmission direction; Obtain the calibration data in the reception direction of the calibration device: The input channel of the calibration device receives the reference synchronization signal output from itself and transmits the signal to the input channel of the calibration source. Use an oscilloscope to measure the signal of the input channel of the calibration source and the reference synchronization signal, compare and record the delay between the signal of the input channel of the calibration source and the reference synchronization signal, and obtain the calibration data in the reception direction.

3. The calibration method of the ATE test equipment according to claim 2, characterized in that, The method for obtaining the calibration data in the reception direction of the calibration device includes: Divide the channels in the calibration device into odd channels and even channels, and use a loopback wire to connect the odd channels and the even channels; When the even channel is used as the output channel and the odd channel is used as the input channel, use the square wave signal output by the calibration source to be transmitted to the odd channel through the even channel, and record the delay data of the odd channel relative to the even channel to obtain the calibration data in the reception direction of the odd channel; When the odd channel is used as the output channel and the even channel is used as the input channel, use the square wave signal output by the calibration source to be transmitted to the even channel through the odd channel, and record the delay data of the odd channel relative to the even channel to obtain the calibration data in the reception direction of the even channel; Use the calibration data in the reception direction of the odd channel and the even channel as the calibration data in the reception direction.

4. The calibration method of the ATE test equipment according to claim 1, characterized in that The steps of measuring and calibrating the single board under test through the calibration device include: Measurement and calibration of the reception direction of the single board under test: The calibration device sends a reference synchronization signal to the single board under test, and the single board under test receives and measures the time when the reference synchronization signal reaches the single board under test to obtain the first original measurement data; Compare the first original measurement data with the calibration data in the transmission direction of the calibration device to obtain the reception direction delay difference of the single board under test, and compensate the reception direction delay difference of the single board under test to the reception direction of the single board under test; Measurement and calibration of the transmission direction of the DUT board: The calibration device collects the square wave signals sent by each channel of the DUT board to the calibration device, measures the trigger time of the rising edge or falling edge of the square wave signal of each channel, and obtains the second original measurement data; after uniformly processing the second original measurement data of each channel, the delay difference of the transmission direction of the DUT board is obtained, and the delay difference is compensated to the transmission direction of the DUT board.

5. A calibration system for an ATE test device, characterized in that, Including a calibration device; The calibration device includes a calibration source, a waveform modulation unit, and a data processing unit; The waveform modulation unit is bidirectionally connected to the calibration source, and the data processing unit is respectively connected to the calibration source and the waveform modulation unit; Among them, the calibration device is connected to multiple channels of the DUT board through signal lines of the same length, and the calibration source is used to provide a calibration signal to the DUT board and collect the response signal of the DUT board.

6. The calibration system of the ATE test equipment according to claim 5, wherein The calibration source includes two parallel first signal paths and second signal paths, and both the first signal path and the second signal path include a fractional delay unit and an integer delay unit connected in sequence.

7. The calibration system of the ATE test equipment according to claim 6, characterized in that, The first signal path is the receiving direction, and the input end is connected to the output end of the waveform modulation unit, and is used to receive and measure the arrival time of the DUT board signal.

8. The calibration system of the ATE test equipment according to claim 6, characterized in that, The second signal path is the transmission direction, and the output end is connected to the input end of the first waveform modulation unit, and is used to send a signal to the DUT board.

9. The calibration system of the ATE test equipment according to claim 6, characterized in that, The waveform modulation unit includes a comparator, and the comparator is connected to the integer delay unit of the first signal path.

10. The calibration system of the ATE test equipment according to claim 5, characterized in that, The calibration device further includes a connector, the connector has multiple channels and is connected to the waveform modulation unit.

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