CN118191712A

CN118191712A - Calibration method and calibration device of chip tester

Info

Publication number: CN118191712A
Application number: CN202410378505.5A
Authority: CN
Inventors: 刘飞; 董亚明; 金晓彬; 季成; 邵健
Original assignee: Suzhou HYC Technology Co Ltd
Current assignee: Suzhou HYC Technology Co Ltd
Priority date: 2024-03-29
Filing date: 2024-03-29
Publication date: 2024-06-14

Abstract

The application relates to a calibration method and a calibration device of a chip tester. The driving module is subjected to integral calibration on the driving values actually output by the driving module at a plurality of preset points, a first error between a first calibration value and a first expected value of the preset points after integral calibration is obtained, if a target preset point with the first error larger than a first setting error of the driving module exists, a second calibration value based on the first calibration value and the first error of the target preset point is determined, and the driving module is subjected to secondary local calibration based on the second calibration value of the target preset point, so that the error of the driving module based on the target preset point is compensated, namely the driving value of the driving module at the target preset point is adjusted, so that the first setting error of the driving module can be met, the integral test precision of the calibrated driving module can meet the requirement, and the driving module can be suitable for a test scene with higher precision requirement.

Description

Calibration method and calibration device of chip tester

Technical Field

The present application relates to the field of chip testing technologies, and in particular, to a calibration method and a calibration device for a chip tester.

Background

With the development of chip testing technology, during the functional testing of a digital chip, an automatic testing machine (Automatic Test Equipmet, ATE), that is, a chip testing machine, generates a specific driving Current (Force Current, FI) or a driving Voltage (FV) according to a testing program programmed by a user, outputs the specific driving Current or the driving Voltage (FV) to an input pin of a tested chip (Device Under Test, DUT), and then the ATE collects a response of the DUT under a specific driving, which is usually a measurement Current (MI) or a Measurement Voltage (MV). The ATE detects whether the chip functions properly by comparing the acquired DUT response value with the expected response value.

However, since the chips used by the drive module and the measurement module inside the ATE have a certain gain and offset error in the design and manufacturing process, there is a difference between the drive value and the measured value of the ATE itself and the actual value. Therefore, in order to ensure that the ATE is able to achieve consistency of expected output and actual measurement, the ATE needs to be calibrated periodically so that the accuracy of the test results of the chip under test can be ensured when the chip under test is tested by the ATE.

In the traditional technology, an external high-precision standard instrument (such as a digital multimeter) is generally used as a calibration tool, and a two-point method is adopted to calibrate an ATE internal driving module and a measuring module respectively, so that although the method can calibrate the ATE to a certain extent, certain errors still exist in the calibration method, and the application scene with higher precision is difficult to meet.

Disclosure of Invention

In view of the foregoing, it is desirable to provide a calibration method, a calibration apparatus, a computer device, a storage medium, and a computer program product for a chip tester capable of improving calibration accuracy.

In a first aspect, the present application provides a calibration method of a chip tester, the chip tester including a driving module, the method comprising:

carrying out integral calibration on the driving values actually output by the driving module at a plurality of preset point positions;

Acquiring a first error between a first calibration value and a first expected value of the preset point location after integral calibration, wherein the first expected value corresponds to the preset point location;

If a target preset point position with the first error larger than the first setting error of the driving module exists, determining a first calibration value based on the target preset point position and a second calibration value of the first error;

and carrying out secondary local calibration on the driving module based on the second calibration value of the target preset point position so as to adjust the driving value of the driving module at the target preset point position to meet the first setting error of the driving module.

In one embodiment, the performing overall calibration on the driving values actually output by the driving module at a plurality of preset points includes:

Acquiring at least two corresponding groups of driving values aiming at least two groups of preset values of the driving module corresponding to the preset point positions;

And performing linear regression fitting according to the at least two groups of preset values and the at least two groups of corresponding driving values to obtain an integral calibration function of the driving module, so as to obtain a first calibration value corresponding to the preset point location based on the integral calibration function.

In one embodiment, the obtaining a first error between the first calibration value and the first expected value of the preset point location after the overall calibration includes:

Acquiring a first calibration value and a corresponding first expected value of the driving module corresponding to the preset point position after integral calibration;

And calculating a difference value between the first calibration value and the corresponding first expected value, and determining the difference value as a first error of the driving module after integral calibration.

In one embodiment, the determining a first calibration value based on a target preset point location and a second calibration value of the first error includes:

obtaining a target interval taking the first expected value as a central value according to the first expected value and the first error corresponding to the target preset point position;

and acquiring a target point position meeting the first setting error from the target interval, and taking a driving value actually output by the target point position as a second calibration value.

In one embodiment, the obtaining the target point location from the target interval, where the target point location meets the first setting error, includes:

Uniformly selecting a plurality of target points in the target interval, and acquiring a driving value actually output by the driving module at the target points;

And calculating a difference value between the driving value actually output by the target point position and a corresponding first expected value to determine a target point position which meets the first setting error and has the minimum difference value.

In one embodiment, the performing the second local calibration on the driving module based on the second calibration value of the target preset point location to adjust the driving value of the driving module at the target preset point location to meet the first setting error of the driving module includes:

performing secondary calibration on the target preset point according to the second calibration value of the target preset point to obtain a secondary calibration function aiming at the target preset point;

And correcting the driving module by adopting the secondary calibration function corresponding to the target preset point position so that the driving values of the target preset point position all meet the first setting error of the driving module.

In one embodiment, the chip tester further includes a measurement module, wherein the method further includes:

Carrying out integral calibration on measured values obtained by the actual measurement of the measurement module in a plurality of preset measurement intervals;

Acquiring a second error between a third calibration value and a second expected value of two endpoints of the preset measurement interval after integral calibration, wherein the second expected value is measured by a third-party test instrument;

If a target preset measurement interval with the second error larger than the second setting error of the measurement module exists, carrying out secondary local calibration on the target preset measurement interval so as to adjust the measurement values of the measurement module in the target preset measurement interval to meet the second setting error of the measurement module.

In one embodiment, if there is a target preset measurement interval in which the second error is greater than the second set error of the measurement module, performing secondary local calibration on the target preset measurement interval includes:

If a target preset measurement interval with the second error larger than the second setting error of the measurement module exists, determining that a measured value in the corresponding target preset measurement interval has deviation from the second expected value corresponding to the measured value;

and respectively carrying out secondary integral calibration on the measured values obtained by the actual measurement of the target preset measurement interval to obtain a secondary calibration function based on the target preset measurement interval.

In a second aspect, the present application provides a calibration device for a chip tester, the chip tester including a drive module, the device comprising:

The first calibration module is used for integrally calibrating the driving values actually output by the driving module at a plurality of preset point positions;

the error acquisition module is used for acquiring a first error between a first calibration value and a first expected value of the preset point location after integral calibration, and the first expected value corresponds to the preset point location;

the calibration value acquisition module is used for determining a first calibration value based on the target preset point position and a second calibration value of the first error if the target preset point position with the first error larger than the first setting error of the driving module exists;

and the second calibration module is used for carrying out secondary local calibration on the driving module based on the second calibration value of the target preset point position so as to adjust the driving value of the driving module at the target preset point position to meet the first setting error of the driving module.

In one embodiment, the chip tester further comprises a measurement module,

The first calibration module is further used for integrally calibrating measured values obtained by the measurement module in actual measurement in a plurality of preset measurement intervals;

The error acquisition module is further used for acquiring a second error between a second calibration value and a second expected value of two endpoints of the preset measurement interval after the integral calibration, wherein the second expected value is measured by a third-party test instrument;

The second calibration module is further configured to perform secondary local calibration on a target preset measurement interval if there is a target preset measurement interval in which the second error is greater than the second set error of the measurement module, so as to adjust measurement values of the measurement module in the target preset measurement interval to meet the second set error of the measurement module.

In a third aspect, the present application provides a chip tester, comprising a testing device and a calibration device,

The testing device comprises at least one module to be calibrated, wherein the module to be calibrated comprises a driving module and a measuring module in a chip testing machine;

The calibration device comprises a memory storing a computer program and a processor implementing the steps of the method described above when executing the computer program.

In a fourth aspect, the present application provides a computer device comprising a memory storing a computer program and a processor implementing the steps of the method described above when the processor executes the computer program.

In a fifth aspect, the present application provides a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of the method described above.

In a sixth aspect, the application provides a computer program product comprising a computer program which, when executed by a processor, implements the steps of the method described above.

According to the calibration method, the device, the computer equipment, the storage medium and the computer program product of the chip tester, through carrying out integral calibration on the driving value actually output by the driving module at a plurality of preset points, and obtaining the first error between the first calibration value and the first expected value of the preset points after integral calibration, if the first error is larger than the target preset point of the first set error of the driving module, determining the first calibration value and the second calibration value based on the target preset point, and carrying out secondary local calibration on the driving module based on the second calibration value of the target preset point, so as to compensate the error of the driving module based on the target preset point, namely, adjusting the driving value of the driving module at the target preset point, so that the first set error of the driving module can be met, and the integral test precision of the calibrated driving module can meet the requirement, thereby being applicable to test scenes with higher precision requirements.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related art, the drawings that are required to be used in the embodiments or the related technical descriptions will be briefly described, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 is a flow chart of a method of calibrating a chip tester in one embodiment;

FIG. 2 is a flow chart illustrating the overall calibration steps performed in one embodiment;

FIG. 3a is a schematic diagram of an actual curve and an ideal curve without overall calibration in one embodiment;

FIG. 3b is a schematic diagram of the actual curve and the ideal curve after the overall calibration in one embodiment;

FIG. 4 is a flowchart illustrating a first error acquisition step according to one embodiment;

FIG. 5 is a flow chart illustrating the steps of determining a second calibration value in one embodiment;

FIG. 6a is a schematic diagram of an actual curve and an ideal curve based on a test target after overall calibration in one embodiment;

FIG. 6b is a schematic diagram of the actual curve and the ideal curve based on the test targets after recalibration according to one embodiment;

FIG. 7 is a flow chart of a calibration method of a chip tester according to another embodiment;

FIG. 8a is a schematic diagram of an actual curve and an ideal curve based on a test target after overall calibration according to another embodiment;

FIG. 8b is a schematic diagram of the actual curve and the ideal curve based on the test targets after recalibration according to another embodiment;

FIG. 9 is a block diagram of a calibration device of a chip tester in one embodiment;

FIG. 10 is a block diagram of a chip tester in one embodiment;

FIG. 11 is an internal block diagram of a chip tester in another embodiment;

Fig. 12 is an internal structural diagram of a computer device in one embodiment.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

In one embodiment, as shown in fig. 1, a calibration method of a chip tester is provided, which is applied to calibration of the chip tester, wherein the chip tester includes a driving module. In this embodiment, the method includes the steps of:

and 102, carrying out integral calibration on the driving values actually output by the driving module at a plurality of preset point positions.

The preset point location may be a point location determined based on an actual application scenario and required to be output for calibration, and specifically may be a driving point location in the driving module, where the driving point location has a certain requirement on the accuracy of an actual output value thereof. For example, if the driving module is required to achieve the highest accuracy of the driving module for the accuracy of the actual output values corresponding to the driving points 3V, 4V and 5V, the driving points 3V, 4V and 5V may be used as preset points for the current calibration. It can be appreciated that the preset point locations may be set to different point locations based on actual application requirements.

The actually output driving value refers to a response value actually obtained under the driving of the corresponding preset point location. Because the chip used by the driving module inside the chip tester has certain gain and offset errors in the design and manufacturing process, the difference exists between the driving value and the actual response value of the chip tester. Therefore, in order to ensure that the driving module can achieve consistency of expected output and actual response, the driving module of the chip tester needs to be calibrated regularly to improve the testing precision of the driving module in the chip tester. The integral calibration refers to a calibration process of correcting the linear error of the driving module on the whole, that is, correcting the linear error of the driving value actually output, and specifically, the integral calibration can be performed based on the linear relationship between a plurality of preset points and the driving value actually output by the corresponding point.

In this embodiment, based on the driving values actually output by the driving module at a plurality of preset points, the driving module is calibrated as a whole, so as to correct the linear error of the driving module as a whole, that is, to correct the linear error of the driving value actually output.

Step 104, obtaining a first error between a first calibration value and a first expected value of the preset point location after the integral calibration.

The first calibration value is obtained by performing integral calibration on the actual output value of the preset point location, and linear errors are eliminated. The first expected value refers to a true value of a driving value corresponding to a preset point location. The first error is the difference between the first calibration value corresponding to the preset point location and the first expected value, that is, the error between the output value and the expected value after the integral calibration is performed.

And 106, if the target preset point position with the first error larger than the first setting error of the driving module exists, determining a first calibration value based on the target preset point position and a second calibration value of the first error.

The first setting error may be determined according to the driving precision of the driving module, for example, the first setting error may be a minimum error that can be achieved by the corresponding driving module, which may also be characterized as a limit precision of the corresponding driving module, or may also be a maximum error corresponding to a target precision that is determined based on an application scenario within a precision range that can be achieved by the driving module, that is, a maximum error that can be accepted under the target precision.

The target preset point location is a preset point location with a corresponding first error larger than a first setting error of the driving module. It can be understood that, for the preset point location where the first error is smaller than or equal to the first setting error of the driving module, the test accuracy of the driving module on the preset point location can meet the requirement, so that the preset point location does not need to be calibrated again. And aiming at the preset point position of which the first error is larger than the first setting error of the driving module, the test precision of the preset point position of the driving module cannot meet the requirement, so that the driving module needs to be calibrated again based on the preset point position, the preset point position is used as a target preset point position, and a first calibration value and a second calibration value based on the first error of the target preset point position are further determined. The second calibration value is used for recalibrating the driving module to compensate the error of the driving module based on the target preset point position, namely, the related data for reducing the first error of the target preset point position, so that the driving value actually output by the target preset point position can meet the first setting error of the driving module.

In this embodiment, after the first error between the first calibration value and the first expected value of the preset point after the overall calibration is obtained, the target preset point may be determined from the preset point based on the corresponding first error, that is, the preset point with the first error greater than the first setting error of the driving module is used as the target preset point, so as to determine the first calibration value and the second calibration value based on the first error of the target preset point, so as to recalibrate the driving module through subsequent steps.

And step 108, carrying out secondary local calibration on the driving module based on a second calibration value of the target preset point position.

Specifically, the driving module is subjected to secondary local calibration based on a second calibration value of the target preset point position. The secondary local calibration is based on calibrating the actual output driving value of the target preset point location, so as to adjust the actual output driving value of the driving module at the target preset point location to meet the calibration process of the first setting error of the driving module.

In the calibration method of the chip tester, the driving values actually output by the driving module at the plurality of preset points are subjected to integral calibration, a first error between the first calibration value and the first expected value of the preset points after integral calibration is obtained, if the first error is larger than the target preset point with the first set error of the driving module, a second calibration value based on the first calibration value and the first error of the target preset point is determined, and the driving module is subjected to secondary local calibration based on the second calibration value of the target preset point, so that the error of the driving module based on the target preset point is compensated, namely, the driving value of the driving module at the target preset point is adjusted, so that the first set error of the driving module can be met, the integral test precision of the calibrated driving module can meet the requirement, and the method is suitable for a test scene with higher precision requirement.

In an exemplary embodiment, as shown in fig. 2, in step 102, performing overall calibration on the driving values actually output by the driving module at a plurality of preset points may specifically include:

Step 202, obtaining at least two sets of corresponding driving values for at least two sets of preset values corresponding to the preset point positions of the driving module.

The preset value is a driving expected value corresponding to the preset point position, namely, the driving module outputs a driving expected value based on the preset point position, and a standard instrument (such as a digital multimeter) measures to obtain a driving actual value, namely, the driving value. Therefore, for a preset point location, a corresponding preset value can be obtained, and a corresponding driving value can be obtained.

In this embodiment, at least two sets of corresponding driving values are obtained for at least two sets of preset values corresponding to the preset point positions of the driving module, so that overall calibration can be performed through subsequent steps.

And 204, performing linear regression fitting according to at least two groups of preset values and at least two groups of corresponding driving values to obtain an overall calibration function of the driving module so as to obtain a first calibration value corresponding to the preset point location based on the overall calibration function.

The linear regression fit is a statistical analysis method for determining the quantitative relationship of the mutual dependence between two or more variables by using regression analysis in mathematical statistics. In this embodiment, linear regression fitting is performed according to at least two sets of preset values and at least two sets of corresponding driving values, so as to obtain an overall calibration function of the driving module, and then overall calibration is performed on the driving module based on the overall calibration function, that is, actual driving values of preset points can be calibrated based on the overall calibration function, so as to obtain calibrated corresponding first calibration values.

Specifically, linear regression fitting is performed according to at least two sets of preset values and at least two sets of corresponding driving values, and the overall calibration function M obtained by the linear regression fitting may be as follows:

wherein/> For the preset value of the ith preset point position, namely the corresponding driving expected value,/>For the driving value actually output by the ith preset point, a and b represent the gain and offset errors between the actual value and the expected value, namely the linear error of the driving module. And solving the minimum value of M to make the partial derivatives of M to a and b respectively be 0, so as to obtain fitting results of a and b. And further, a first calibration value corresponding to the preset point position can be obtained based on the fitting result of the a and the b.

In an exemplary embodiment, taking a two-point calibration method in linear regression fit as an example, the above-described overall calibration is further described. When two-point calibration is used, the overall calibration function described above can be expressed as:

by obtaining two groups of preset values and two corresponding groups of driving values and integrally calibrating the function Fitting is performed to complete a fitting relationship between the preset value of the driving module and the actually output driving value, thereby determining the values of a and b.

As shown in fig. 3a, when the overall calibration is not performed, a larger error exists between the actual curve of the driving value actually output by the preset point location and the ideal curve of the preset value, and the overall relationship is y=ax+b. Assuming that the preset value for a certain preset point is f (i.e., X), the driving value actually output (i.e., Y) becomes af+b due to the linear relationship. In order to realize integral calibration, that is, for a preset value f, the desired actual output driving value is also f, based on the above linear relationship, it is known that the driving preset value applied to the driving module cannot be f, the driving preset value f needs to be converted into (f-b)/a to be denoted as f 'through the intermediate layer, and then the (f-b)/a is output by the driving module, so that the obtained actual output driving value is af' +b (substituting parameters to obtain a [ (f-b)/a ] +b), that is, the obtained actual output driving value is f, thereby completing integral calibration of the driving module. As shown in fig. 3b, the error between the actual curve of the first calibration value corresponding to the preset point position and the ideal curve of the preset value is smaller after the integral calibration is performed.

In an exemplary embodiment, as shown in fig. 4, in step 104, obtaining a first error between a first calibration value and a first expected value of the preset point after the overall calibration may specifically include:

step 402, obtaining a first calibration value and a corresponding first expected value of the driving module after integral calibration at a preset point.

The first calibration value is obtained by performing integral calibration on the actual output value of the preset point location, and linear errors are eliminated. The first expected value refers to a true value of a driving value corresponding to a preset point location. Specifically, a first calibration value and a corresponding first expected value of the driving module at a preset point position after integral calibration are obtained, and whether the driving module meets the requirements after the integral calibration is determined through subsequent steps.

In step 404, a difference between the first calibration value and the corresponding first expected value is calculated, and the difference is determined as a first error of the driving module after the overall calibration.

The first error is the difference between the first calibration value corresponding to the preset point location and the first expected value, that is, the error between the output value and the expected value after the integral calibration is performed. Specifically, the difference value is determined as a first error of the driving module after the overall calibration is performed by calculating the difference value between the first calibration value and the corresponding first expected value.

For example, for a preset point location with a driving voltage of 1V in the driving module, it is generally expected that the driving voltage actually output by the driving module will also be 1V, i.e. the first expected value corresponding to the preset point location is 1V, and then the first expected value corresponds to the preset point location. If the actual output driving value, i.e. the output voltage, is 0.9V, after the overall calibration, if the actual output driving value is calibrated to be 0.99V, then 0.99V is the first calibration value of the preset point location. Then 0.99-1 = -0.01V is the first error between the first calibration value and the first expected value of the preset point location.

In an exemplary embodiment, as shown in fig. 5, in step 106, determining the first calibration value and the second calibration value based on the first error of the target preset point location may specifically include:

Step 502, obtaining a target interval with the first expected value as a central value according to the first expected value and the first error corresponding to the target preset point position.

The target interval is a point location interval for searching for a target point location capable of meeting higher precision requirements. Because the actual output effect of the driving module does not strictly meet the linear relation of the integral calibration function, the driving module after integral calibration may still not meet the measurement accuracy requirement in terms of the first error between the first calibration value of some preset points and the corresponding first expected value, i.e. the first error is greater than the first set error corresponding to the measurement accuracy requirement, so that the target preset point with the first error greater than the first set error can be determined, and then secondary local calibration is performed.

Specifically, a target interval taking the first expected value as a central value can be obtained through the first expected value and the first error corresponding to the target preset point position, namely, the target interval taking the first expected value as the central value, taking the difference value between the first expected value and the first error as a starting point and taking the sum of the first expected value and the first error as an end point is obtained. And performing secondary local calibration on the target preset point position based on the target interval.

As shown in fig. 6a, the driving point circled in the figure is the first calibration value for the target preset point, and still deviates from the ideal curve by a certain distance, that is, the first error between the first calibration value and the first expected value of the driving module after the integral calibration based on the target preset point is greater than the first setting error of the driving module. Assuming that the first error between the corresponding first calibration value and the expected value of the target preset point x is offset, since the first error offset is greater than the first set error of the driving module, the error cannot be eliminated by directly converting the driving value actually output by the target preset point x into x+offset.

For example, if the accuracy of the driving module after the overall linear calibration is 0.001, that is, the first error offset is not more than 0.001, but in a certain test scenario, the accuracy of the driving module needs to be 0.0001, that is, the first setting error of the driving module is 0.0001, that is, the error between the driving value actually output by the driving module and the driving expected value is not more than 0.0001. Therefore, even if the driving value actually output by the target preset point is directly converted into x+0.001, the accuracy requirement of 0.0001 for the first setting error cannot be met.

Based on the first expected value and the first error corresponding to the target preset point position, a target interval taking the first expected value as a central value can be obtained. Specifically, if the preset target point location is x (i.e., the first expected value corresponding to the point location is x), the first error between the corresponding first calibration value and the first expected value x is offset, and the corresponding target interval may be determined as [ x-offset, x+offset ].

And step 504, acquiring a target point position meeting the first setting error from the target interval, and taking the driving value actually output by the target point position as a second calibration value.

Specifically, a plurality of target points are uniformly selected in a target interval, a driving value actually output by a driving module at the target points is obtained, and a difference value between the driving value actually output by the target points and a corresponding first expected value is calculated to determine a target point with a minimum difference value meeting a first setting error.

For example, with the target preset point position being 2, if the driving value actually output after the overall calibration, that is, the first calibration value is 2.0001, the corresponding first error is 0.0001, if the driving module is required to reach 0.00009 for the accuracy of the target preset point position 2, that is, the first error between the corresponding first calibration value and the first expected value is not more than 0.00009 for the target preset point position 2, that is, the first setting error, because the actual first error is 0.0001 is greater than the first setting error 0.00009, the driving module needs to be further calibrated again.

Specifically, the corresponding target interval may be determined to be [2-0.0001,2+0.0001] based on the above steps. By uniformly sampling in the interval, for example, 10 sampling points, namely target points, can be averaged in the interval, the difference between the first calibration values and the first expected values of the ten points are respectively obtained, and the point with the difference smaller than the first setting error and the minimum difference is searched. If the first calibration value actually output by the point location 1.99996 is 2.00002 and the error between the actual output and 2 is 0.00002, if the error is the minimum error in the interval and is smaller than the requirement of the first setting error of 0.00009, the point location 1.99996 can be determined as the target point location meeting the first setting error, and the second calibration value is determined based on the first calibration value 2.00002 actually output by the point location 1.99996. It can be understood that, after uniform sampling, if the minimum error is still greater than the first set error, that is, when the target point position meeting the condition is not found, the sampling granularity can be further reduced, so as to obtain more sampling points, and further, the target point position meeting the condition is found from more sampling points.

The second calibration value is related data for recalibrating the driving module to compensate the error of the driving module based on the target preset point position, namely related data for reducing the error.

Further, in step 108, the second local calibration of the driving module based on the second calibration value of the target preset point is: performing secondary calibration on the target preset point according to the second calibration value of the target preset point to obtain a secondary calibration function aiming at the target preset point, and correcting the driving module by adopting the secondary calibration function corresponding to the target preset point so that the driving values of the target preset point all meet the first setting error of the driving module.

Specifically, after the first integral calibration is performed, the integral calibration function of all preset points is assumed to be y=ax+b, so that target preset points which do not meet the requirements in all preset points are screened out based on the first setting error.

The secondary calibration of the driving module at the target preset point is essentially to replace x with x 'with higher precision, and the difference between the two is c=x' -x, where c is the offset.

Calibration of the target preset point location may be understood as applying the secondary calibration function before applying the overall calibration function. Therefore, in practical application, for the target preset point x, the target point x 'of the replacement x is brought into y=ax+b to obtain ax' +b, so as to obtain the output meeting the first setting error.

The difference between the integral calibration process, which is equivalent to the combination of the secondary calibration function and the integral calibration function and is changed into y=a (x+c) +b=ax+ac+b, and can be expressed as y=ax ' +b ', and the integral calibration process which is only needed to be realized at other preset points is that a is not changed, only b is changed, and b ' is changed.

Therefore, in order to distinguish the secondary calibration from the overall calibration, the secondary calibration function is defined as y=x+c.

Still further to the above embodiment, if the target preset point is 2 and the target point determined by the target interval and satisfying the first setting error is 1.99996, the driving module may calculate the error of the corresponding point, that is, the second calibration value is (1.99996-2), that is, -0.00004. Because the actual output driving value can meet the first setting error of the driving module when the target point is 1.99996, in the secondary calibration process, the driving module converts the driving value of the target preset point 2 into 1.99996 through the intermediate layer and then applies the 1.99996 to the driving module for output, namely, the driving of the target preset point 2 is corrected through the second calibration value, and the secondary calibration function for the target preset point can be the sum of the target preset point 2 and the second calibration value, so that the error still existing on the target preset point by the driving module after the integral calibration is applied is eliminated. As shown in fig. 6b, the driving value actually output by the driving point circled in the figure, that is, the target preset point is overlapped with the ideal curve, so that the testing precision of the driving module on the target preset point is improved.

In an exemplary embodiment, the chip tester further includes a measurement module, and as shown in fig. 7, the calibration method for the chip tester may further include:

step 702, performing overall calibration on the measured values obtained by the measurement module in the actual measurement in a plurality of preset measurement intervals.

The preset measurement interval may be a measurement interval which is configured for the measurement module in advance and needs to be calibrated, and may be configured for different intervals based on an actual application scenario. The measured value obtained by actual measurement is based on the input corresponding to the preset measurement interval, and the measured value obtained by actual measurement by the measurement module.

The chip used by the measuring module inside the chip tester has certain gain and offset errors in the design and manufacturing process, so that the measured value of the chip tester is different from the expected input value. Therefore, in order to ensure that the measurement module can achieve consistency of actual measurement and expected input, the measurement module of the chip tester needs to be calibrated regularly to improve measurement accuracy of the measurement module in the chip tester. The overall calibration refers to a calibration process of correcting the linear error of the measurement module as a whole, that is, correcting the linear error of the actual measurement value, and specifically, the overall calibration may be performed based on the linear relationship between the measurement values obtained by actually measuring in a plurality of preset measurement intervals.

The overall calibration may be based on a two-point calibration method, that is, by obtaining measured values of two end points of a preset measurement interval and corresponding expected values, and fitting with a preset linear function y=ax+b, so as to complete a fitting relationship between the actual measured values and the expected values of the measurement module, thereby determining the values of a and b. And carrying out integral calibration on the actual measurement quantity of the preset measurement interval based on the fitting relation.

Referring to fig. 3a, there is a large error between the measured value (i.e., the actual curve composed of the output measured values) and the expected value (i.e., the ideal curve composed of the inputs applied to the measurement module) when the overall calibration is not performed, and the overall is in a linear relationship of y=ax+b. Assuming that the input applied to the measurement module is m (i.e., X), the output measurement (i.e., Y) becomes am+b, denoted as m', due to the linear relationship. In order to achieve calibration, i.e. for an input m applied by the measurement module, the desired output measurement value is also m instead of m ', the output measurement value can be converted into (m' -b)/a (substituted parameter [ (am+b) -b ]/a) by the intermediate layer based on the above-mentioned linear relationship, i.e. the obtained output measurement value is m, so that the overall calibration of the measurement module is completed. As shown in fig. 3b, the error between the measured value (i.e. the actual curve) and the expected value (i.e. the ideal curve) is smaller after the overall calibration is performed.

Step 704, obtaining a second error between the third calibration value and the second expected value of the two end points of the preset measurement interval after the overall calibration.

The third calibration value is obtained by performing integral calibration on the actual measurement values of the two endpoints of the preset measurement interval, wherein the linear error is eliminated. The second expected value is a measurement true value corresponding to two endpoints of the preset measurement interval, and can be measured by a third party test instrument. The second error is the difference between the third calibration value and the second expected value corresponding to the two ends of the preset measurement interval, that is, the error between the actual measurement value and the expected value after the integral calibration is performed.

Step 706, if there is a target preset measurement interval with the second error greater than the second set error of the measurement module, performing a secondary local calibration on the target preset measurement interval.

The second setting error may be determined according to the driving precision of the measurement module, for example, the second setting error may be a minimum error that can be achieved by the corresponding measurement module, which may also be characterized as a limit precision of the corresponding measurement module, or may also be a maximum error corresponding to a target precision that is determined based on an application scenario within a precision range that can be achieved by the measurement module, that is, a maximum error that can be accepted under the target precision.

The target preset measurement interval is a preset measurement interval of which the corresponding second error is larger than the second set error of the measurement module. It can be understood that, for a preset measurement interval in which the second error is less than or equal to the second set error of the measurement module, the measurement accuracy of the measurement module in the preset measurement interval can meet the requirement, so that the preset measurement interval does not need to be calibrated again. And aiming at a preset measurement interval with a second error larger than a second setting error of the measurement module, the measurement accuracy of the measurement module in the preset measurement interval cannot meet the requirement, so that the measurement module needs to be recalibrated based on the preset measurement interval, the preset measurement interval is used as a target preset measurement interval, and the target preset measurement interval is subjected to secondary local calibration so as to adjust the measurement values of the measurement module in the target preset measurement interval to meet the second setting error of the measurement module.

Specifically, in step 706, the performing secondary local calibration on the target preset measurement interval may specifically include: if a target preset measurement interval with the second error larger than the second setting error of the measurement module exists, judging that a measured value in the corresponding target preset measurement interval has deviation from a second expected value corresponding to the measured value; and respectively carrying out secondary integral calibration on the measured values obtained by the actual measurement of the target preset measurement interval to obtain a secondary calibration function based on the target preset measurement interval.

Since after the measurement module is calibrated as a whole, there is still a certain gain and offset error between the measured value actually measured in some measurement intervals (i.e. the actual curve) and the corresponding expected value (i.e. the ideal curve). As shown in fig. 8a, the actual curve of the measurement interval (i.e., the target preset measurement interval) circled in the figure still deviates from the ideal curve by a certain distance (i.e., the second error of the measurement module after the overall calibration is greater than the corresponding second setting error based on the target preset measurement interval), so that further recalibration of the measurement module is required.

Specifically, when recalibration is performed, recalibration may be performed according to a linear relationship between a third calibration value of the actual measured values of the two endpoints on the target preset measurement interval and the corresponding second expected value. For example, if the target preset measurement interval is a measurement interval L with a certain measurement error as shown in fig. 8a, the two endpoints refer to a start endpoint L1 and an end endpoint L2 of the measurement interval L on an ideal curve, and the second expected value may be expected values corresponding to the start endpoint L1 and the end endpoint L2 on the ideal curve respectively, which are also input values that need to be applied to the measurement module in the calibration process. The third calibration value is a measurement value obtained by respectively measuring and performing overall calibration by the measurement module after respectively inputting the expected values corresponding to the start endpoint l1 and the end endpoint l2 to the measurement module. The expected value of the starting endpoint L1 of the measurement interval L and the corresponding measured value after one integral calibration are obtained, and the expected value of the ending endpoint L2 of the measurement interval L and the corresponding measured value after one integral calibration are obtained.

Further, in this embodiment, the recalibration method may be consistent with the overall calibration method, and a two-point calibration method may be still adopted, that is, the expected value and the measured value corresponding to the start endpoint L1 and the end endpoint L2 of the obtained measurement interval range L are respectively adopted, and a preset linear function y=ax+b is adopted to perform fitting, where Y is the measured value, and X is the expected value, so as to obtain a fitting relationship between the expected value and the measured value corresponding to the start endpoint L1 and the end endpoint L2 of the measurement interval range L, where the measurement module is based on the measurement interval range L, and determine the values of a and b. a and b characterize the gain and offset error between the measured and expected values of the measurement module. And the actual measurement quantity of the target preset measurement interval can be calibrated based on the fitting relation, namely the measured values of the adjustment measurement module in the target preset measurement interval all meet the second setting error of the measurement module. As shown in fig. 8b, the error between the measured value (i.e. the actual curve) and the expected value (i.e. the ideal curve) of the recalibrated measurement module based on the target preset measurement interval is smaller. Namely, the measurement value points circled in the graph (namely, the measurement value aiming at the target preset measurement interval) are overlapped with an ideal curve, so that the measurement accuracy of the measurement module on the target preset measurement interval is improved.

It can be understood that, since the calibration method adopted for recalibrating the measurement module is consistent with the method during integral calibration, the recalibration process of the measurement module is consistent with the integral calibration process, which will not be described in detail in this embodiment.

It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.

Based on the same inventive concept, the embodiment of the application also provides a calibration device for realizing the calibration method of the chip testing machine. The implementation of the solution provided by the device is similar to that described in the above method, so the specific limitation in the embodiments of the calibration device of one or more chip testers provided below may be referred to the limitation of the calibration method of the chip tester hereinabove, and will not be repeated herein.

In an exemplary embodiment, as shown in fig. 9, there is provided a calibration device of a chip tester, where the chip tester includes a driving module, and the calibration device specifically includes: a first calibration module 902, an error acquisition module 904, a calibration value acquisition module 906, and a second calibration module 908, wherein:

the first calibration module 902 is configured to perform overall calibration on the driving values actually output by the driving module at a plurality of preset points;

An error obtaining module 904, configured to obtain a first error between a first calibration value and a first expected value of the preset point location after the overall calibration, where the first expected value corresponds to the preset point location;

A calibration value obtaining module 906, configured to determine a first calibration value based on the target preset point location and a second calibration value of the first error if there is the target preset point location where the first error is greater than the first setting error of the driving module;

And a second calibration module 908, configured to perform secondary local calibration on the driving module based on the second calibration value of the target preset point location, so as to adjust the driving values of the driving module at the target preset point location to all meet the first setting error of the driving module.

In an exemplary embodiment, the chip testing machine further includes a measurement module, and the first calibration module is further configured to perform overall calibration on measurement values actually measured by the measurement module in a plurality of preset measurement intervals; the error acquisition module is further used for acquiring a second error between a second calibration value and a second expected value of two endpoints of the preset measurement interval after the integral calibration, wherein the second expected value is measured by a third-party test instrument; the second calibration module is further configured to perform secondary local calibration on a target preset measurement interval if there is a target preset measurement interval in which the second error is greater than the second set error of the measurement module, so as to adjust measurement values of the measurement module in the target preset measurement interval to meet the second set error of the measurement module.

In an exemplary embodiment, the second calibration module is specifically further configured to: if a target preset measurement interval with the second error larger than the second setting error of the measurement module exists, determining that a measured value in the corresponding target preset measurement interval has deviation from the second expected value corresponding to the measured value; and respectively carrying out secondary integral calibration on the measured values obtained by the actual measurement of the target preset measurement interval to obtain a secondary calibration function based on the target preset measurement interval.

In an exemplary embodiment, the first calibration module is specifically further configured to: acquiring at least two corresponding groups of driving values aiming at least two groups of preset values of the driving module corresponding to the preset point positions; and performing linear regression fitting according to the at least two groups of preset values and the at least two groups of corresponding driving values to obtain an integral calibration function of the driving module, so as to obtain a first calibration value corresponding to the preset point location based on the integral calibration function.

In an exemplary embodiment, the error acquisition module is specifically further configured to: acquiring a first calibration value and a corresponding first expected value of the driving module corresponding to the preset point position after integral calibration; and calculating a difference value between the first calibration value and the corresponding first expected value, and determining the difference value as a first error of the driving module after integral calibration.

In an exemplary embodiment, the calibration value acquisition module is specifically further configured to: obtaining a target interval taking the first expected value as a central value according to the first expected value and the first error corresponding to the target preset point position; and acquiring a target point position meeting the first setting error from the target interval, and taking a driving value actually output by the target point position as a second calibration value.

In an exemplary embodiment, the calibration value acquisition module is further configured to: uniformly selecting a plurality of target points in the target interval, and acquiring a driving value actually output by the driving module at the target points; and calculating a difference value between the driving value actually output by the target point position and a corresponding first expected value to determine a target point position which meets the first setting error and has the minimum difference value.

In an exemplary embodiment, the second calibration module is specifically further configured to: performing secondary calibration on the target preset point according to the second calibration value of the target preset point to obtain a secondary calibration function aiming at the target preset point; and correcting the driving module by adopting the secondary calibration function corresponding to the target preset point position so that the driving values of the target preset point position all meet the first setting error of the driving module.

The various modules in the calibration device of the chip tester described above may be implemented in whole or in part by software, hardware, or a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

Based on the same inventive concept, the embodiments of the present application further provide a chip tester, and it can be appreciated that the implementation schemes of solving the problems provided by the chip tester are similar to those described in the above method, so specific limitations in embodiments of one or more chip testers provided below can be referred to above for limitations of a calibration method of the chip tester, which are not repeated herein.

As shown in fig. 10, the chip tester includes a testing device 1002 and a calibration device 1004, wherein:

The testing device 1002 includes at least one module to be calibrated, including a driving module and a measuring module in the chip tester;

The calibration device 1004 includes a memory and a processor, where the memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program, so as to calibrate a driving module and a measuring module in the chip tester, and obtain a calibrated test device; the calibrated testing device is used for performing functional detection on the tested chip based on the testing target.

In an exemplary embodiment, the internal structure of the chip tester is shown in fig. 11, and the chip tester includes a lower computer FPGA (Field Programmable GATE ARRAY ) and an upper computer, where the upper computer and the lower computer communicate through a high-speed serial bus connection. The lower computer FPGA part comprises a main control module, a data storage module, a driving module and a measuring module. Specifically, the main control module directly controls the functional modules of the board card to realize driving or measurement, the data storage module is used for storing calibration data, and the main control module can extract the calibration data and apply the calibration data before driving or after measurement so as to meet the requirement of test precision.

The upper computer part comprises a calibration flow control module, a secondary calibration function module, a calibration data management module and a board card control driving module. Specifically, the board card control driving module interacts with the main control module of the FPGA to control the board card, the calibration flow control module executes the whole calibration flow or calls the secondary calibration function module to acquire second calibration data according to the calibration requirement, and the second calibration data is stored in the data storage module of the FPGA part of the lower computer after being tidied by the calibration data management module.

The upper computer calibration flow control module can call the lower computer FPGA main control module or the upper computer board card control driving module, reads the linear relation stored in the calibration data management module during integral calibration, and carries out integral linear calibration on the driving module and the measuring module. After the integral linear calibration is applied, the gain and offset errors existing in the chip are greatly improved, and in order to meet the test requirement of higher precision, secondary calibration is still needed to be carried out for compensating the small errors aiming at special driving points and measuring intervals.

The calibration flow control module of the upper computer can execute the calibration function in the secondary calibration function module on the board card to obtain a second calibration function according to the special precision requirement of the driving point position or the measurement interval set by the user. And then the calibration data management module is responsible for sorting and storing the data into the data storage module in the lower computer FPGA. And then, a lower computer FPGA main control module is called to read a second calibration function in the data storage module, the driving module and the measuring module are calibrated again, or an upper computer board card is called to control the driving module to read the second calibration function of the calibration data management module, and the driving module and the measuring module are calibrated again so as to compensate errors locally existing after integral linear calibration, thereby meeting the test requirement of higher precision.

Specifically, the main control module, the driving module, and the measuring module may be configured as the above-described test device 1002, and the data storage module, the calibration flow control module, the secondary calibration function module, the calibration data management module, and the board control driving module may be configured as the above-described calibration device 1004.

The various modules of the chip tester described above may be implemented in whole or in part by software, hardware, and combinations thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In an exemplary embodiment, a computer device, which may be a terminal, is provided, and an internal structure thereof may be as shown in fig. 12. The computer device includes a processor, a memory, an input/output interface, a communication interface, a display unit, and an input means. The processor, the memory and the input/output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input/output interface. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input/output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a method of calibrating a chip tester. The display unit of the computer device is used for forming a visual picture, and can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, can also be a key, a track ball or a touch pad arranged on the shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.

It will be appreciated by those skilled in the art that the structure shown in FIG. 12 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the computer device to which the present inventive arrangements may be applied, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.

In an exemplary embodiment, a computer device is provided comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the method as described above when the computer program is executed.

In one embodiment, a computer readable storage medium is provided, having stored thereon a computer program which, when executed by a processor, implements the steps of the method as described above.

In an embodiment, a computer program product is provided, comprising a computer program which, when executed by a processor, implements the steps of the method as described above.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magneto-resistive random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (PHASE CHANGE Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in various forms such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The databases referred to in the embodiments provided herein may include at least one of a relational database and a non-relational database. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processor referred to in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, or the like, but is not limited thereto.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be assessed as that of the appended claims.

Claims

1. A method of calibrating a chip tester, the chip tester including a drive module, the method comprising:

2. The calibration method according to claim 1, wherein the performing overall calibration on the driving values actually output by the driving module at a plurality of preset points comprises:

3. The method according to claim 1, wherein the obtaining a first error between the first calibration value and the first expected value of the preset point location after the overall calibration includes:

4. The method of calibrating according to claim 1, wherein said determining a first calibration value based on a target preset point location and a second calibration value of said first error comprises:

5. The method according to claim 4, wherein the obtaining the target point location satisfying the first setting error from the target zone includes:

6. The calibration method according to claim 1, wherein the performing the secondary local calibration on the driving module based on the second calibration value of the target preset point location to adjust the driving values of the driving module at the target preset point location to each meet the first setting error of the driving module includes:

7. The calibration method of any one of claims 1-6, the chip tester further comprising a measurement module, wherein the method further comprises:

8. The method according to claim 7, wherein if there is a target preset measurement interval in which the second error is greater than the second set error of the measurement module, performing a secondary local calibration on the target preset measurement interval includes:

9. A calibration device for a chip tester, the chip tester comprising a drive module, the device comprising:

10. The calibration device of claim 9, wherein the chip tester further comprises a measurement module,