Method, device and system for controlling probe position of wafer inspection platform

Abstract

The present invention relates to a method, device and system for controlling the position of a probe of a wafer inspection platform. The method comprises: continuously measuring the position information of the probe, sampling the position information at a preset time interval to obtain a sampling signal, and executing a control signal acquisition step once each time a new sampling signal is obtained; the control signal acquisition step comprises: S1, holding the new sampling signal through a zero-order holder to obtain sampling data x k ; S2, x k The discrete continuous observer is input to obtain a continuous estimated position signal x. S3: x and the probe's desired position signal r are input to the position tracking controller to obtain a position tracking control signal u. S4: x and u are used as inputs to the disturbance compensator to obtain a disturbance compensation control signal w. S5: u and w are added together to provide the control input signal for the probe position. This invention overcomes the influence of factors such as model uncertainty and external interference, improving the control accuracy of the probe's motion position. It only requires the probe position sampling signal, making it more convenient for engineering applications.

Description

Technical Field

[0001] The present invention relates to the field of wafer detection technology, and in particular to a probe position control method, device and system for a wafer detection platform. Background Art

[0002] With the vigorous development of the semiconductor industry, the requirements for wafer production and testing are becoming increasingly higher. The wafer inspection table is a common equipment used for wafer production testing, with the characteristics of high precision, high speed, and high stability. Probe testing is an important test item in the production and manufacturing process of semiconductor silicon wafers. Probe testing is the process of using a probe card to contact the pads on the wafer to transmit electrical signals. The probe card is the interface between the test instrument and the device under test. The common probe card in testing is a printed circuit board with many fine needles. During the test, these fine needles will make physical and electrical contact with the device under test. The probe transmits voltage and current in and out of the pads in the wafer test. That is, the wafer inspection table contacts the test contact pads on the wafer through the probes on the probe card. The test table will send test electrical signals, which are input into the die on the wafer through the probes and the pads in contact with the probes to obtain test data. Therefore, it is particularly important to control the position of the probes on the wafer inspection table.

[0003] However, the traditional probe position control method has uncertainty in the model and poor ability to respond to external interference, which makes the probe position control accuracy low. The traditional control method requires the use of continuous probe position and speed signals, but in practice can only measure discrete sampling signals of the position, which cannot meet the actual application requirements. Therefore, it is necessary to design a new anti-interference position control method based on the probe position sampling signal. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the existing technology and provide a probe position control method for a wafer inspection table, which can overcome the influence of factors such as model uncertainty and external interference, improve the control accuracy of the probe movement position, and only requires the sampling signal of the probe position, which is more convenient for engineering applications.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a probe position control method for a wafer inspection platform, comprising:

[0006] Continuously measure the position information of the probe on the wafer test table, sample the position information at a preset time interval to obtain a sampling signal, and execute a control signal acquisition step every time a new sampling signal is obtained; the control signal acquisition step includes:

[0007] S1, hold the new sampling signal through the zero-order holder to obtain the sampling data x k ;

[0008] S2, the sample data x k Input the discrete continuous observer to obtain the continuous estimated position signal x;

[0009] S3, inputting the estimated position signal x and the preset probe expected position signal r into the position tracking controller to obtain the position tracking control signal u;

[0010] S4, taking the estimated position signal x and the position tracking control signal u as inputs of the disturbance compensator to obtain the disturbance compensation control signal w;

[0011] S5, adding the position tracking control signal u and the disturbance compensation control signal w as the control input signal of the probe position to realize the control of the motion position of the probe.

[0012] Furthermore, the control signal acquisition step further includes:

[0013] S6: Input the position tracking control signal u and the disturbance compensation control signal w into the discrete continuous observer, update the estimated position signal x, and then return to S3.

[0014] Furthermore, the design method of the discrete continuous observer is:

[0015]

[0016]

[0017] Where v represents the auxiliary state variable, l1 and l2 are positive observer gain coefficients, t and t k are the current moment and the sampling moment of the sampling signal respectively, e is the base of the natural logarithm, and M(x) is the probe inertia matrix function with x as the independent variable.

[0018] Furthermore, the construction algorithm of the position tracking controller is:

[0019] u=-k1(xr)-θ

[0020]

[0021] Among them, k1 and k2 are positive controller gain coefficients, and θ is an auxiliary variable with no practical significance.

[0022] Furthermore, the construction algorithm of the disturbance compensator is:

[0023] w=M -1 (x)(-αu+α∫udt)

[0024] Among them, α is a positive filter parameter, M -1(x) is the inverse matrix of M(x), and M(x) is the probe inertia matrix function with x as the independent variable.

[0025] The present invention also provides a probe position control signal acquisition device for a wafer inspection platform, comprising:

[0026] The zero-order hold is used to hold the sampled signal at zero order to obtain the sampled data x k ;

[0027] Discrete continuous observer for the sampled data x k , obtain the continuous estimated position signal x;

[0028] A position tracking controller, configured to obtain a position tracking control signal u based on the estimated position signal x and a preset probe expected position signal r;

[0029] a disturbance compensator for obtaining a disturbance compensation control signal w based on the estimated position signal x and the position tracking control signal u;

[0030] The control signal generator is used to add the position tracking control signal u and the disturbance compensation control signal w to obtain the control input signal of the probe position.

[0031] The present invention also provides a probe position control system for a wafer inspection platform, comprising:

[0032] A measurement module, used to continuously measure the position information of the probe on the wafer test table;

[0033] A sampling module, configured to sample the position information at preset time intervals to obtain a sampling signal;

[0034] A probe position control signal acquisition device for a wafer inspection platform.

[0035] In order to solve the above technical problems, the technical solution of the present invention is:

[0036] After adopting the above technical solution, the present invention has the following beneficial effects:

[0037] 1. The present invention adopts a discrete-continuous observer to estimate continuous position and velocity signals using discrete position sampling signals, eliminating the need to measure the velocity of the probe, simplifying the control system structure and saving costs;

[0038] 2. The present invention only needs to use discrete position sampling signals to obtain the control input signal of the probe position, which is more in line with engineering application requirements;

[0039] 3. In view of factors such as model uncertainty and external interference, the present invention improves the accuracy of probe position control by estimating and compensating for uncertain models and disturbances. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural diagram of the probe position control system of the wafer inspection platform of the present invention. DETAILED DESCRIPTION

[0041] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0042] Example 1

[0043] like Figure 1 As shown, a probe position control method for a wafer inspection platform includes:

[0044] Continuously measure the position information of the probe on the wafer test table, sample the position information at a preset time interval to obtain a sampling signal, and execute a control signal acquisition step every time a new sampling signal is obtained, so that the probe can move according to the desired position; the control signal acquisition step includes:

[0045] S1, hold the new sampling signal through the zero-order holder to obtain the sampling data x k ;

[0046] S2, the sample data x k Input the discrete continuous observer to obtain the continuous estimated position signal x;

[0047] S3, inputting the estimated position signal x and the preset probe expected position signal r into the position tracking controller to obtain the position tracking control signal u;

[0048] S4, taking the estimated position signal x and the position tracking control signal u as inputs of the disturbance compensator to obtain the disturbance compensation control signal w;

[0049] S5, adding the position tracking control signal u and the disturbance compensation control signal w as the control input signal of the probe position to realize the control of the motion position of the probe.

[0050] In this embodiment, the control signal acquisition step further includes:

[0051] S6: Input the position tracking control signal u and the disturbance compensation control signal w into the discrete continuous observer, update the estimated position signal x, and then return to S3.

[0052] In the control signal acquisition step of this embodiment, the estimated position signal x can be continuously updated, thereby updating the position tracking control signal u, the disturbance compensation control signal w, and the control input signal of the probe position.

[0053] In this embodiment, the design method of the discrete continuous observer is:

[0054]

[0055]

[0056] Where v represents the auxiliary state variable, l1 and l2 are positive observer gain coefficients, t and t k are the current time and the sampling time of the sampled signal, respectively. e is the base of the natural logarithm. M(x) is the probe inertia matrix function with x as the independent variable. The initial values ​​of the position tracking control signal u and the disturbance compensation control signal w are set to 0.

[0057] In this embodiment, the construction algorithm of the position tracking controller is:

[0058] u=-k1(xr)-θ

[0059]

[0060] Among them, k1 and k2 are positive controller gain coefficients, and θ is an auxiliary variable with no practical significance.

[0061] In this embodiment, the construction algorithm of the disturbance compensator is:

[0062] w=M -1 (x)(-αu+α∫udt)

[0063] Among them, α is a positive filter parameter, M -1 (x) is the inverse matrix of M(x), and M(x) is the probe inertia matrix function with x as the independent variable.

[0064] Example 2

[0065] like Figure 1 As shown, a probe position control signal acquisition device for a wafer inspection platform includes:

[0066] The zero-order hold is used to hold the sampled signal at zero order to obtain the sampled data x k ;

[0067] Discrete continuous observer for the sampled data x k , obtain the continuous estimated position signal x;

[0068] A position tracking controller, configured to obtain a position tracking control signal u based on the estimated position signal x and a preset probe expected position signal r;

[0069] a disturbance compensator for obtaining a disturbance compensation control signal w based on the estimated position signal x and the position tracking control signal u;

[0070] The control signal generator is used to add the position tracking control signal u and the disturbance compensation control signal w to obtain the control input signal of the probe position.

[0071] Example 3

[0072] like Figure 1 As shown, a probe position control system for a wafer inspection platform includes:

[0073] A measurement module, used to continuously measure the position information of the probe on the wafer test table;

[0074] A sampling module, configured to sample the position information at preset time intervals to obtain a sampling signal;

[0075] A probe position control signal acquisition device for a wafer inspection platform as described in the second embodiment.

[0076] In this embodiment, each time a new sampling signal is obtained, the probe position control signal acquisition device of the wafer inspection platform is used to perform a control signal acquisition step.

[0077] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A probe position control method for a wafer inspection platform, characterized in that: include: Continuously measure the position information of the probe on the wafer test table, sample the position information at a preset time interval to obtain a sampling signal, and execute a control signal acquisition step every time a new sampling signal is obtained; the control signal acquisition step includes: S1, hold the new sampling signal through the zero-order holder to obtain the sampling data x k ; S2, the sample data x k Input the discrete continuous observer to obtain the continuous estimated position signal x; S3, inputting the estimated position signal x and the preset probe expected position signal r into the position tracking controller to obtain the position tracking control signal u; S4, taking the estimated position signal x and the position tracking control signal u as inputs of the disturbance compensator to obtain the disturbance compensation control signal w; S5, adding the position tracking control signal u and the disturbance compensation control signal w as the control input signal of the probe position to realize the control of the motion position of the probe.

2. The method for controlling the position of a probe of a wafer inspection platform according to claim 1, wherein: The control signal acquisition step further includes: S6: Input the position tracking control signal u and the disturbance compensation control signal w into the discrete continuous observer, update the estimated position signal x, and then return to S3.

3. The method for controlling the position of a probe of a wafer inspection platform according to claim 2, wherein: The design method of the discrete continuous observer is: Where v represents the auxiliary state variable, l1 and l2 are positive observer gain coefficients, t and t k are the current moment and the sampling moment of the sampling signal respectively, e is the base of the natural logarithm, and M(x) is the probe inertia matrix function with x as the independent variable.

4. The method for controlling the position of a probe of a wafer inspection platform according to claim 1, wherein: The construction algorithm of the position tracking controller is: u=-k1(xr)-θ Among them, k1 and k2 are positive controller gain coefficients, and θ is an auxiliary variable with no practical significance.

5. The method for controlling the position of a probe of a wafer inspection platform according to claim 1, wherein: The construction algorithm of the disturbance compensator is: w=M -1 (x)(-αu+α∫udt) Among them, α is a positive filter parameter, M -1 (x) is the inverse matrix of M(x), and M(x) is the probe inertia matrix function with x as the independent variable.

6. A probe position control signal acquisition device for a wafer inspection platform, characterized in that: include: The zero-order hold is used to hold the sampled signal at zero order to obtain the sampled data x k ; Discrete continuous observer for the sampled data x k , obtain the continuous estimated position signal x; A position tracking controller, configured to obtain a position tracking control signal u based on the estimated position signal x and a preset probe expected position signal r; a disturbance compensator for obtaining a disturbance compensation control signal w based on the estimated position signal x and the position tracking control signal u; The control signal generator is used to add the position tracking control signal u and the disturbance compensation control signal w to obtain the control input signal of the probe position.

7. A probe position control system for a wafer inspection platform, characterized in that: include: A measurement module, used to continuously measure the position information of the probe on the wafer test table; A sampling module, configured to sample the position information at preset time intervals to obtain a sampling signal; The probe position control signal acquisition device for the wafer inspection platform as described in claim 6.

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