阅读说明：本技术 一种集成电路测试系统时间参数校准方法及校准装置 (Time parameter calibration method and device for integrated circuit test system ) 是由 顾翼 周厚平 孙崇钧 于 2019-12-11 设计创作，主要内容包括：本发明属于集成电路测试系统校准技术,为一种集成电路测试系统时间参数校准方法及校准装置。该校准方法通过测量集成电路测试系统测试通道多种指标分量,包括通道间同步偏差时间,通道传输延迟时间等分量。根据分量的测量数值结果进行计算,可以通过时间参数测量误差量化计算方法定量分析并计算出测试系统在进行集成电路时间参数测量过程中所引入的系统偏差。该系统偏差值可以进行量值修正以提升集成电路时间参数测量结果的准确度。该装置由同步偏差时间测量装置、通道切换装置、测量适配器组成等部分组成。本发明所提供的校准方法具有较高的适应性和多通道测量能力,校准装置具有精度高,自动化程度高等特点。(The invention belongs to the calibration technology of an integrated circuit test system, and relates to a time parameter calibration method and a calibration device of the integrated circuit test system. The calibration method tests multiple index components of the channel by measuring the integrated circuit test system, including components such as synchronous deviation time between channels, channel transmission delay time and the like. And calculating according to the measurement value result of the component, and quantitatively analyzing and calculating the system deviation introduced by the test system in the integrated circuit time parameter measurement process by using a time parameter measurement error quantitative calculation method. The system offset value may be magnitude corrected to improve accuracy of the integrated circuit time parameter measurements. The device consists of a synchronous deviation time measuring device, a channel switching device, a measuring adapter and the like. The calibration method provided by the invention has higher adaptability and multi-channel measurement capability, and the calibration device has the characteristics of high precision, high automation degree and the like.)

1. A method for calibrating time parameters of an integrated circuit test system, the method comprising the steps of:

s1, measuring the time parameter of the integrated circuit by using the integrated circuit test system, and performing item measurement on each test channel of the integrated circuit test system to obtain the synchronous deviation time and the transmission delay time;

and S2, calculating the system error introduced by the integrated circuit test system in the process of measuring the time parameter of the integrated circuit through a formula.

2. The method as claimed in claim 1, wherein the step of performing the itemized measurements in step S1 comprises:

optionally selecting one channel from the test channels as a reference channel, and optionally selecting two channels from the rest channels as an m channel and an n channel;

selecting n channels to provide driving signals, and taking m channels as measuring signal channels; setting the transmission delay time of n channels as t_pdnMeasuring the transmission delay time of m channels as t_pdm(ii) a Let the synchronization deviation time of n channels relative to the reference channel be Δ t_nThe synchronization deviation time of the m channel relative to the reference channel is delta t_m。

3. The method as claimed in claim 1, wherein the formula in step S2 is specifically as follows:

t_syserr＝t_Dn+t_Rm

t_Dn＝t_pdn-Δt_n

t_Rm＝t_pdm+Δt_m

wherein, t_syserrRepresenting systematic errors, t, introduced by measurements of time parameters of integrated circuits_DnSignal drive offset for n channels, t_RmThe offset is measured for the signals of the m channels.

4. The method as claimed in claim 2, wherein the propagation delay time t is a delay time t_pdn、t_pdmDirect measurements can be made by time domain reflectometry.

5. The time parameter calibration device of the integrated circuit test system is characterized by comprising an integrated circuit test system time parameter calibration device (2), and specifically comprising a synchronous deviation time measurement device (201), a channel switching device (202) connected with the synchronous deviation time measurement device (201) through a cable, and a measurement adapter (203) connected with the channel switching device (202) through a cable.

6. An IC test system time parameter calibration device according to claim 5, wherein said synchronization deviation time measurement device (201) has a ten picosecond time interval measurement function.

7. The apparatus of claim 5, wherein the channel switching device (202) is a three-axis motion device based on a rectangular coordinate system or a polar coordinate system, and has a function of clamping the test probe and the cable.

8. The device for calibrating the time parameters of the integrated circuit test system according to claim 5, wherein the measurement adapter (203) is a double-sided PCB board with a via structure, the interfaces of the PCB board are a front-side pad (2031) and a back-side pad (2032), the front-side pad (2031) has uniformly distributed pads pogopad (20311), and the back-side pad (2032) has uniformly distributed test pads (20321); the pad pogopad (20311) is connected with a test pad (20321) through a via, and the back surface test pad (20321) is divided into a square and a circle in shape and is alternately and uniformly distributed on the back surface pad (2032).

Technical Field

The invention relates to the field of integrated circuit test calibration, in particular to a calibration technology and a device suitable for time parameter calibration of an integrated circuit test system.

Background

Parameters such as the flip time, delay time, and pulse width of an integrated circuit device are time-related parameters, and are collectively referred to as integrated circuit time parameters. The measurement and the setting of the time parameters of the integrated circuit are realized by testing the time parameters through an integrated circuit testing system, so that the testing system needs to calibrate the components of the testing system related to the time parameters before measuring the time parameters of the integrated circuit components, the accuracy and the reliability of the testing system are ensured, and the purpose of accurately measuring the time parameters of the integrated circuit is achieved. The digital channel is used as a main component of an integrated circuit test system and is also used as a main component for bearing the measurement of time parameters of the integrated circuit.

Disclosure of Invention

Aiming at the problems in the prior art, a method and a device for calibrating time parameters of an integrated circuit test system are provided.

The purpose of the invention is realized by the following technical scheme:

according to a first aspect of the present invention, a method for calibrating time parameters of an integrated circuit test system comprises the following steps:

s1, measuring the time parameter of the integrated circuit by using the integrated circuit test system, and performing item measurement on each test channel of the integrated circuit test system to obtain the synchronous deviation time and the transmission delay time;

and S2, calculating the system error introduced by the integrated circuit test system in the process of measuring the time parameter of the integrated circuit through a formula.

In the above aspect, the itemized measurement in step S1 includes:

optionally selecting one channel from the test channels as a reference channel, and optionally selecting two channels from the rest channels as an m channel and an n channel;

selecting n channels to provide driving signals, and taking m channels as measuring signal channels; setting the transmission delay time of n channels as t_pdnMeasuring the transmission delay of m channelsTime t_pdm(ii) a Let the synchronization deviation time of n channels relative to the reference channel be Δ t_nThe synchronization deviation time of the m channel relative to the reference channel is delta t_m。

In the above aspect, the formula in step S2 is specifically:

t_syserr＝t_Dn+t_Rm

t_Dn＝t_pdn-Δt_n

t_Rm＝t_pdm+Δt_m

wherein, t_syserrRepresenting systematic errors, t, introduced by measurements of time parameters of integrated circuits_DnSignal drive offset for n channels, t_RmThe offset is measured for the signals of the m channels.

In the above aspect, the transmission delay time t_pdn、t_pdmDirect measurements can be made by time domain reflectometry.

According to a second aspect of the present invention, the apparatus comprises an ic test system time parameter calibration apparatus, specifically comprising a synchronous skew time measurement apparatus, a channel switching apparatus connected to the synchronous skew time measurement apparatus through a cable, and a measurement adapter connected to the channel switching apparatus through a cable.

In the above aspect, the synchronization deviation time measuring device has a ten picosecond interval measuring function.

In the above aspect, the channel switching device is a three-axis movement device based on a rectangular coordinate system or a polar coordinate system, and has a function of clamping the test probe and the cable.

In the above aspect, the measurement adapter is a double-sided PCB board with a via structure, the interfaces of the PCB board are front-side pads and back-side pads, the front-side pads have pads pogopads distributed uniformly, and the back-side pads have test pads distributed uniformly; the pad pogopad is connected with the testing pad through a via hole, and the back testing pad is divided into a square shape and a circular shape and is alternately and uniformly distributed on the back pad.

The invention has the following beneficial effects:

1. the method has higher universality, and can realize traversal calibration of time parameters of each test channel of the test system aiming at the calibration requirement of a high-speed (more than 400 Mbps) large-scale (more than 100 test channels) test system;

2. the device has higher precision, and the precision of the device can be improved in an external measurement mode;

3. the device has higher degree of automation and certain portability, and is convenient to be used for calibrating test systems under different field environments.

Drawings

FIG. 1 is a schematic diagram of an integrated circuit time parameter measurement error in an embodiment of a method for calibrating time parameters of an integrated circuit test system according to the present invention;

FIG. 2 is a diagram illustrating a time parameter measurement error itemization quantization of an integrated circuit test system according to an embodiment of a method for calibrating time parameters of an integrated circuit test system according to the present invention;

FIG. 3 is a schematic diagram of an apparatus for calibrating time parameters of an integrated circuit test system according to the present invention;

FIG. 4 is a schematic diagram illustrating channel switching in an embodiment of a time parameter calibration apparatus for an integrated circuit test system according to the present invention;

FIG. 5 is a schematic diagram of a double-sided structure of a measurement adapter of the time parameter calibration apparatus for an integrated circuit test system according to the present invention;

FIG. 6 is a side cross-sectional view of a measurement adapter of the time parameter calibration apparatus for an integrated circuit test system according to the present invention.

Detailed Description

In order to further understand the contents, features and effects of the present invention, the following embodiments are described in detail with reference to the accompanying drawings.

The following description of the embodiments of the present invention is provided in connection with the accompanying drawings.

The invention relates to a method and a device for calibrating time parameters of an integrated circuit test system, which are used for measuring the system error of the integrated circuit test system so as to improve the accuracy of the test system in measuring the time parameters of the integrated circuit.

When the test system performs time parameter measurement of the integrated circuit 70, the test channel 101 needs to be used, and particularly when the flip time measurement is performed, two test channels need to be used to perform time difference measurement on the input 701 and the output pin 702, respectively, so that time synchronization deviation between the two channels and transmission delay time of the first transmission line 1011 and the second transmission line 1012 between the channels and the integrated circuit to be tested are the most main sources of time parameter measurement errors of the integrated circuit, as shown in fig. 1.

In view of the above problems, the present invention provides a method for calibrating time parameters of an integrated circuit test system, as shown in fig. 2. The channel ch11011 is selected as a reference channel, and the synchronization deviation time of the other channels relative to the reference channel and the transmission delay time of the channel are measured respectively, so as to form a time parameter measurement distribution diagram of each test channel as shown in fig. 3. In fig. 3, the abscissa is the amount of time and the ordinate is the test channel number.

For example, with the channel ch1 as the reference channel as shown in fig. 2, the offset time of any other channel with respect to the channel ch11011 is represented as a symmetrical distribution centered on the transmission delay in the coordinate system. If channel chn is selected to provide the drive signal and channel chm is selected to be the measurement signal channel, then the time-parameter system error t of the integrated circuit, measured in dependence upon chn and chm, is determined_syserrExpressed as:

t_syserr＝t_Dn+t_Rm

t_Dn＝t_pdn-Δt_n

t_Rm＝t_pdm+Δt_m

wherein t is_syserrThe system error introduced for the time parameter measurement of the integrated circuit is a calculated value; as shown by t_DnThe signal driving deviation 601 of n channels when the driving signal of n channels is adopted is a calculated value; t is t_RmThe signal measurement deviation 603 of the m channel is a calculated value when the m channel measurement signal is adopted; t is t_pdnFor transmission delay of n channelsInterval 602, which is a measured value; t is t_pdmThe propagation delay time 604 for the m channel is a measurement; Δ t_nThe synchronization deviation time 605 for the n channels relative to the reference channel is the measured value; Δ t_mIs the synchronization deviation time 606 of the m channel relative to the reference channel, is the measured value.

Propagation delay time t of channel itself_pdn、t_pdmThe channel resources can be utilized to carry out direct measurement through a time domain reflection method, and the dependence on external resources is not needed. The channel deviation time measurement is the problem to be solved by the invention.

The device 2 for calibrating time parameters of an integrated circuit test system according to the present invention is generally shown in the figure, and the main hardware components include: a synchronization deviation time measuring device 201, a channel switching device 202, a measurement adapter, etc. 203. The synchronization deviation time measuring device 201 characterizes the synchronization deviation time between the measured channel and the reference channel by measuring the signal time interval between the measured channel and the reference channel. The number of channels to be tested is large, and the measurement resources of the measurement device 201 are limited, so that different test channels need to be switched to the measurement device 201. The channel switching device 202 adopted by the invention realizes switching among different testing channels in a mechanical switching mode, the switching device 202 clamps the testing cable and interfaces to be butted with the tested channel, and the testing line and the measuring device are ensured to be unique in the measuring process of each channel. How to ensure that the measurement results are consistent by mechanical switching is explained in detail below:

the standard reference channel ch11011 in fig. 4 is connected to the synchronous deviation time measuring device through a coaxial cable by a micro-strip line on the calibration adapter plate rotating an SMA interface. The channels to be measured (including ch2, ch 3.) are connected to the synchronization deviation time measuring device 203 through the through hole 2033 on the measuring adapter 203 by a probe and a coaxial cable, which are common to all channels to be measured except for the through hole 2033. It can be seen that the respective signal transmission paths of the standard reference channel and the measured channel are completely different, and at least the following aspects are involved to affect the digital channel synchronization deviation time measurement result:

1. the difference between the microstrip line in the signal transmission path of the standard reference channel ch11011 and the via hole 2033 in the signal transmission path of the channel to be tested;

2. the difference between the probe and the coaxial cable in the signal transmission path of the standard reference channel ch11011 and the tested channel;

3. the synchronous deviation time measuring device measures the time deviation between two measuring interfaces.

In order to solve the inherent error introduced by the measurement result caused by the problems, the project is to eliminate all influencing factors by a mathematical method.

According to the connection scheme in fig. 4, a standard reference channel ch11011 and a channel ch21012 to be measured are used for channel synchronization deviation time measurement, and the measured deviation time of the channel ch21012 relative to the channel ch11011 is t2, then:

t₂＝x₂-y₂

in the formula: x2 is the true value, and y2 is the error introduced by different signal transmission paths.

And (3) performing channel synchronization deviation time measurement by using a standard reference channel ch11011 and a channel to be measured ch3, and measuring the deviation time of ch3 relative to ch11011 as t3, then:

t₃＝x₃-y₃，

in the formula: x3 is the true value, and y3 is the error introduced by different signal transmission paths.

The following set of equations is established:

in the system of equations: since the only difference between the ch21012 and ch3 channel signal paths is the via less than 3mm on their calibration adapter board, the error it introduces is relatively small (roughly around 15ps converted to signal transmission time based on the 3mm via length), so y2 ≈ y 3. The channel synchronization deviation time between the channel ch21012 and the channel ch3 can be calculated by the equation set as:

t₂₃＝t₂-t₃＝x₂-x₃

the calculation result shows that the measurement result of the synchronization deviation time between the channels ch21012 and ch3 eliminates the influence of the signal transmission path of the standard reference channel ch11011, and the result is independent of the standard reference channel ch 11011.

The measurement adapter depicted in fig. 4 is a PCB board with a front-back via-through structure, as shown in fig. 5, the interfaces are planar copper pads 2031, 2032, the front interface is a standard pad pogopad2033 required by a test system, the front interface is directly connected to a test pad2034 on the back side through a via, and the shape of the back pad2034 is divided into a square and a circle to distinguish a signal interface from a GND interface, so that image recognition and probe alignment can be conveniently performed by a mechanical switching device.

It will be appreciated by those skilled in the art from the foregoing description of construction and principles that the invention is not limited to the specific embodiments described above, and that modifications and substitutions based on those skilled in the art are intended to be included within the scope of the invention as defined by the following claims and their equivalents. The parts not described in the specification are prior art or common general knowledge. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.