Motor control method for improving wafer stability

Abstract

The application relates to a motor control method for improving wafer stability, which collects position information of a PIN needle in a wafer carrying process, dynamically monitors the state of the PIN needle in the wafer carrying process, collects state monitoring information, generates a PWM signal based on the position information and the state monitoring information, and performs closed-loop control on a PIN driving motor; the technical scheme provided by the application can effectively overcome the defects that the wafer is difficult to be smoothly translated and lifted when the wafer is heated in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to semiconductor equipment, in particular to a motor control method for improving wafer stability. BACKGROUND

[0002] The main function of the hot plate is to heat the wafer, so it is necessary to repeatedly take and place the wafer on the heating core, so the main technology involved in the hot plate is to smoothly and quickly take and place the wafer.

[0003] Compared with domestic and foreign, the traditional wafer taking and placing method mainly uses a stepping motor to drive the horizontal direction carrying mechanism (TCP), and uses a cylinder to complete the lifting of the PIN (vertical direction carrying mechanism). The electromagnetic valve is used to control the air inlet and air outlet of the cylinder to drive the lifting of the PIN, which has the advantages of simple control and can realize speed switching by adjusting the frequency and air pressure of the air inlet and air outlet. For example, the invention patent application with the application publication number CN115881610A discloses a method and device for controlling the movement speed of the lifting mechanism, which mainly uses a double-acting cylinder to drive the lifting of the lifting mechanism.

[0004] However, the PIN lifting driven by the cylinder has a great disadvantage, that is, the flexibility of speed control during the lifting of the PIN is insufficient, especially when the wafer is on the TCP and the PIN lifts the wafer, and when the wafer is on the heating core and the PIN lifts the wafer. The above two actions are the contact between the PIN and the wafer during the movement of the cylinder, so excessive speed will cause violent collision between the PIN and the wafer, and further cause wafer deviation and damage, which will have a great impact on the later wafer processing. SUMMARY

[0005] In view of the above-mentioned defects of the prior art, the present application provides a motor control method for improving wafer stability, which can effectively overcome the defects of the prior art that it is difficult to smoothly translate and lift the wafer during wafer heating.

[0006] To achieve the above purpose, the present application realizes the following technical solutions:

[0007] A motor control method for improving wafer stability collects position information of the PIN during wafer carrying, dynamically monitors the state of the PIN during wafer carrying, collects state monitoring information, and generates a PWM signal based on the position information and the state monitoring information, and performs closed-loop control on the PIN driving motor;

[0008] When the horizontal direction carrying mechanism drives the wafer to enter the inside of the hot plate above the heating core, the wafer needs to be lifted, and the PIN driving motor is controlled according to the following process:

[0009] The PIN needle initially locates at the lower limit position, and the PIN driving motor is controlled to accelerate smoothly;

[0010] The PIN needle is driven to run at the maximum speed for a distance to shorten the lifting time;

[0011] The speed is reduced to the minimum speed before the PIN needle is lifted to the wafer;

[0012] The PIN needle is smoothly moved for a distance after being lifted to the wafer;

[0013] The speed is increased after the wafer is stabilized on the PIN needle, and the PIN needle is lifted to the upper limit position, and the PIN driving motor stops working;

[0014] When the wafer is heated on the hot core inside the hot plate, and the wafer needs to be lifted after the heating work is completed, the PIN driving motor is controlled according to the following process:

[0015] The PIN needle initially locates at the lower limit position, and the PIN driving motor is controlled to run smoothly at the minimum speed;

[0016] The PIN needle is smoothly accelerated after being lifted to the wafer;

[0017] The PIN needle is driven to run at the maximum speed for a distance to shorten the lifting time;

[0018] Finally, the speed of the PIN needle is gradually reduced to the minimum speed, and the PIN needle is lifted to the upper limit position, and the PIN driving motor stops working;

[0019] The lower limit position and the upper limit position are determined by the state monitoring information, and the switching position of the PIN needle movement state is determined by the position information.

[0020] Preferably, when the wafer is on the horizontal direction carrying mechanism, the process of the PIN needle lifting the wafer is divided into five stages:

[0021] 1) S10~S11: S10 is the starting position of the PIN needle, i.e. the position where the first acceleration movement of the PIN needle starts, the speed here is the minimum speed Min_Speed, S11 is the position where the first acceleration movement of the PIN needle ends, i.e. the position where the first constant speed movement of the PIN needle starts, the speed here is the maximum speed Max_Speed, and the movement of the PIN needle in this stage is:

[0022] a = J * t ;

[0023] v = at = J *t 2 ;

[0024] wherein, a is the acceleration, J is the jerk, i.e. the rate of change of acceleration, t is the running time, v is the speed;

[0025] If v ≥ Max_Speed, then v = Max_Speed; If a ≥ Max_Accel, then a = Max_Accel, wherein Max_Accel is the maximum acceleration;

[0026] 2) S11~S12: S12 is the position where the first uniform motion of the PIN ends, i.e. the position where the deceleration motion of the PIN starts, the speed at this position is still the maximum speed Max_Speed, the motion of the PIN in this stage is as follows:

[0027] v = Max_Speed;

[0028] 3) S12~S13: S13 is the position where the PIN contacts the wafer, i.e. the position where the deceleration motion of the PIN ends and the second uniform motion of the PIN starts, the speed at this position is the minimum speed Min_Speed, the deceleration control in this stage is performed by using the deceleration corresponding to the stage S0~S1, the deceleration degree is set by the first deceleration speed percentage Decel1_Speed_Persent in combination with the position where the deceleration motion ends, the motion of the PIN in this stage is as follows:

[0029] v = Max_Speed - ( at * Decel1_Speed_Persent);

[0030] If v ≤ Min_Speed, then v = Min_Speed; If the PIN does not drop to the minimum speed Min_Speed when contacting the wafer, the position where the first uniform motion of the PIN ends needs to be adjusted to ensure that the speed of the PIN when contacting the wafer is the minimum speed Min_Speed;

[0031] 4) S13~S14: S14 is the position where the second section of the PIN needle ends uniform motion, i.e. the position where the second section of the PIN needle starts accelerated motion, the speed at this position is still the minimum speed Min_Speed, in this stage, the PIN needle lifts the wafer at the minimum speed Min_Speed for a distance, the motion of the PIN needle in this stage is as follows:

[0032] v =Min_Speed;

[0033] 5) S14~S15: S15 is the position where the second section of the PIN needle ends accelerated motion, i.e. the stop position, at this time, the PIN lifting limit sensor is triggered, the PIN driving motor brake is stopped, the PIN needle in this stage is as follows:

[0034] v = J * t 2 *Decel2_Speed_Persent;

[0035] wherein, Decel2_Speed_Persent is the second section deceleration acceleration percentage.

[0036] Preferably, when the wafer is on the heating core of the hot plate, the process of the PIN needle lifting the wafer is divided into five stages:

[0037] 1) S20~S21: S20 is the starting position of the PIN needle, i.e. the position where the first section of the PIN needle starts uniform motion, the speed at this position is the minimum speed Min_Speed, S21 is the position where the first section of the PIN needle ends uniform motion, i.e. the position where the PIN needle starts accelerated motion, the speed at this position is still the minimum speed Min_Speed, the motion of the PIN needle in this stage is as follows:

[0038] v =Min_Speed;

[0039] If the current running step number is 0.05 times of the preset total step number of a single stroke, the uniform motion at the minimum speed Min_Speed is completed, and the wafer is slowly lifted;

[0040] 2) S21~S22: S22 is the position where the PIN needle ends accelerated motion, i.e. the position where the second section of the PIN needle starts uniform motion, the speed at this position is the maximum speed Max_Speed, the motion of the PIN needle in this stage is as follows:

[0041] a = J * t ;

[0042] v = at = J * t 2 ;

[0043] If v ≥ Max_Speed, then v = Max_Speed; If a ≥ Max_Accel, then a = Max_Accel;

[0044] 3) S22~S23: S23 is the position where the second segment of the PIN needle ends its uniform motion, i.e., the first segment of the PIN needle starts its deceleration motion. The speed here is still the maximum speed Max_Speed. The motion of the PIN needle in this stage is as follows:

[0045] v = Max_Speed;

[0046] 4) S23~S24: S24 is the position where the first segment of the PIN needle ends its deceleration motion, i.e., the second segment of the PIN needle starts its deceleration motion. The speed here is:

[0047] v = Max_Speed - Max_Accel * t * Decel1_Speed_Persent;

[0048] The motion of the PIN needle in this stage is as follows:

[0049] v = Max_Speed - ( at * Decel1_Speed_Persent);

[0050] If v ≤ Min_Speed, then v = Min_Speed;

[0051] 5) S24~S25: S25 is the position where the second segment of the PIN needle ends its deceleration motion, i.e., the stop position. The speed here is the minimum speed Min_Speed, achieving slow stop. The motion of the PIN needle in this stage is as follows:

[0052] v = v - ( at * Decel2_Speed_Persent);

[0053] If v ≤ Min_Speed, then v = Min_Speed.

[0054] Preferably, when the PIN needle descending / horizontal direction carrying mechanism enters the hot plate / horizontal direction carrying mechanism return, the TCP driving motor and PIN driving motor control logic in the three cases are the same, and the motion of the PIN needle and the horizontal direction carrying mechanism is divided into four stages, taking the PIN needle as an example:

[0055] 1) S30~S31: S30 is the starting position of the PIN needle, that is, the position where the PIN needle starts to accelerate, the speed here is the minimum speed Min_Speed, S31 is the position where the PIN needle ends to accelerate, that is, the position where the PIN needle starts to move at a constant speed, the speed here is the maximum speed Max_Speed, and the motion of the PIN needle in this stage is:

[0056] a = J * t ;

[0057] v = at = J * t 2 ;

[0058] If v ≥Max_Speed, then v =Max_Speed; If a ≥Max_Accel, then a =Max_Accel;

[0059] 2) S31~S32: S32 is the position where the PIN needle ends to move at a constant speed, that is, the position where the PIN needle starts to decelerate for the first time, the speed here is still the maximum speed Max_Speed, and the motion of the PIN needle in this stage is:

[0060] v =Max_Speed;

[0061] 3) S32~S33: S33 is the position where the PIN needle ends to decelerate for the first time, that is, the position where the PIN needle starts to decelerate for the second time, the speed here is:

[0062] v =Max_Speed-Max_Accel*t*Decel1_Speed_Persent;

[0063] The motion of the PIN needle in this stage is:

[0064] v =Max_Speed-( at*Decel1_Speed_Persent);

[0065] If v ≤Min_Speed, then v =Min_Speed;

[0066] 4) S33~S34: S34 is the position of the second segment of the PIN needle deceleration motion, that is, the stop position, and the speed here is the minimum speed Min_Speed, which realizes slow stop, and the motion of the PIN needle in this stage is as follows:

[0067] v = v -( at *Decel2_Speed_Persent);

[0068] If v ≤Min_Speed, then v =Min_Speed.

[0069] Preferably, the closed-loop control process is completed by a control mainboard, and the control mainboard comprises a CPU, a CAN communication module, a DI state monitoring module, a PWM signal generation module and a motor driving module.

[0070] The CAN communication module exchanges data with the PLC through CAN communication mode.

[0071] The DI state monitoring module adopts an isolation optocoupler to monitor the output signal of the limit sensor in real time, and sends each high and low level to the GPIO port of the corresponding CPU through an isolation circuit.

[0072] The CPU calculates the speed and acceleration of the horizontal conveying mechanism and the PIN needle at each node according to the built-in algorithm, and counts the running steps during the operation of the driving motor, compares the running steps with the preset total steps of a single stroke, collects the position information of the horizontal conveying mechanism and the PIN needle during the wafer conveying process, receives the signals sent by the DI state monitoring module, dynamically monitors the state of the horizontal conveying mechanism and the PIN needle during the wafer conveying process, collects the state monitoring information, and controls the corresponding timer interrupt based on the motion of the horizontal conveying mechanism and the PIN needle at each node, as well as the position information and the state monitoring information.

[0073] The PWM signal generation module sends PWM signals to the STEP port of the motor driving module through an isolation chip under the action of the timer interrupt.

[0074] The motor driving module controls the TCP driving motor and the PIN driving motor to accelerate, decelerate and run at a constant speed at the corresponding position under the control of the PWM signal.

[0075] Compared with the prior art, the motor control method for improving wafer stability provided by the application adopts step motors to drive the horizontal direction carrying mechanism and the PIN needle, combines advanced and flexible program design and algorithm operation, can subdivide and optimize the motion mode and speed control of each action link, and high-quality complete the whole translation and lifting action of the wafer, avoids strong vibration from causing wafer deviation and damage, at the same time, the stable lifting action can prevent the photoresist on the wafer from flowing abnormally, ensures that the photoresist surface uniformity of the wafer will not change, and is beneficial to the later wafer processing. BRIEF DESCRIPTION OF DRAWINGS

[0076] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0077] Figure 1 The figure is a schematic diagram of the PIN needle supporting the wafer when the wafer is on the horizontal direction carrying mechanism in the application;

[0078] Figure 2 The figure is a schematic diagram of the PIN needle supporting the wafer when the wafer is on the heating hot core of the hot plate in the application;

[0079] Figure 3 The figure is a schematic diagram of the speed change of the PIN needle during the process of the PIN needle supporting the wafer when the wafer is on the horizontal direction carrying mechanism in the application;

[0080] Figure 4 The figure is a schematic diagram of the speed change of the PIN needle during the process of the PIN needle supporting the wafer when the wafer is on the heating hot core of the hot plate in the application;

[0081] Figure 5 The figure is a schematic diagram of the speed change of the PIN needle / horizontal direction carrying mechanism when the PIN needle descends / horizontal direction carrying mechanism enters the hot plate / horizontal direction carrying mechanism returns in the application;

[0082] Figure 6 The figure is a detection result diagram of the comparative experiment in the application;

[0083] Figure 7 The figure is a structural schematic diagram of the wafer carrying device in the application;

[0084] Figure 8 The figure is a structural schematic diagram of the wafer carrying device after removing the hot plate in the application; Figure 7 The figure is a structural schematic diagram of the wafer carrying device after removing the hot plate in the application;

[0085] Figure 9 For the purpose of the present application Figure 7 The schematic diagram of the partial structure of the wafer carrying device;

[0086] Figure 10 For the purpose of the present application Figure 7 The schematic diagram of the structure of the PIN driving motor driving the PIN needle;

[0087] Figure 11 For the purpose of the present application Figure 10 The schematic diagram of the bottom structure;

[0088] Figure 7 In the present application

[0089] 1, horizontal carrying mechanism; 2, TCP driving motor; 3, TCP return limit sensor; 4, PIN needle; 5, PIN driving motor; 6, horizontal carrying mechanism belt roller; 7, PIN lead screw; 8, PIN needle descending limit sensor; 9, PIN needle ascending limit sensor; 10, TCP entering limit sensor; 11, heating core. DETAILED DESCRIPTION

[0090] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0091] The specific process and technical effects of the motor control method for improving wafer stability provided by the present application will be introduced below in conjunction with specific examples.

[0092] The specific process includes: collecting the position information of the PIN needle in the wafer carrying process, dynamically monitoring the state of the PIN needle in the wafer carrying process, collecting the state monitoring information, and generating a PWM signal based on the position information and the state monitoring information to control the PIN driving motor in a closed loop;

[0093] When the horizontal carrying mechanism drives the wafer to enter the heating core directly above the heat plate, the wafer needs to be jacked up, and the PIN driving motor is controlled according to the following process:

[0094] The PIN needle is initially located at the lower limit position, and the PIN driving motor is controlled to accelerate smoothly;

[0095] Drive the PIN needle to run at the maximum speed for a distance to shorten the jacking time;

[0096] Minimize the speed before the PIN needle touches the wafer;

[0097] Smoothly move a distance after the PIN needle touches the wafer;

[0098] Increase the speed when the wafer is stable on the PIN needle, and the PIN needle upper limit sensor is triggered when the PIN needle moves to the upper limit position, at which time the PIN drive motor stops working;

[0099] When the wafer is heated on the hot core inside the hot plate, and needs to be lifted after the heating work is completed, control the PIN drive motor according to the following process:

[0100] The PIN needle is initially located at the lower limit position, and the PIN drive motor is controlled to run smoothly at the minimum speed;

[0101] Smoothly accelerate after the PIN needle touches the wafer;

[0102] Run a distance at the maximum speed to shorten the lifting time;

[0103] Finally, gradually reduce the speed of the PIN needle to the minimum speed, and the PIN needle upper limit sensor is triggered when the PIN needle moves to the upper limit position, at which time the PIN drive motor stops working;

[0104] The lower limit position and the upper limit position are determined by the state monitoring information, and the switching position of the PIN needle movement state is determined by the position information.

[0105] Figures 7-11 The figure is a schematic diagram of the wafer handling device in the present application, and the names and functions of each number in the figure are as follows:

[0106] 1-Horizontal handling mechanism: a device for horizontally handling wafers, and each time the wafer falls on its plane;

[0107] 2-TCP drive motor: a step motor for driving the horizontal handling mechanism to move horizontally;

[0108] 3-TCP return limit sensor: a limit sensor for returning the horizontal handling mechanism to zero and stopping, which triggers the sensor after the horizontal handling mechanism moves to the specified position, and the TCP drive motor immediately stops to ensure consistent stopping position;

[0109] 4-PIN needle: a device for vertically handling wafers, and the PIN device has three ceramic pins, which lift the wafer to complete the lifting and lowering action;

[0110] 5-PIN drive motor: a step motor for driving the PIN needle to move vertically;

[0111] 6- Horizontal transport mechanism belt roller: for cooperation with TCP drive motor, and combined with the belt to drive horizontal transport mechanism movement device;

[0112] 7- PIN screw rod: for driving PIN up and down movement device, and its lower end gear, with PIN drive motor through the belt connection (such as Figure 10 and Figure 11 shown);

[0113] 8- PIN needle down limit sensor: for PIN needle down limit sensor, PIN needle down to the specified position, trigger sensor, PIN drive motor will immediately stop, ensure consistent stop position;

[0114] 9- PIN needle up limit sensor: for PIN needle up limit sensor, PIN needle up to the specified position, trigger sensor, PIN drive motor will immediately stop, ensure consistent stop position;

[0115] 10- TCP into limit sensor: for horizontal transport mechanism into the hot plate inside limit sensor, horizontal transport mechanism to the specified position, trigger sensor, TCP drive motor will immediately stop, ensure consistent stop position;

[0116] 11- heating hot core: for heating wafer device, ceramic material, the whole hot plate wafer transport is in the process of taking on the heating hot core.

[0117] The whole device will be placed on the wafer heating hot core on the process includes the following stages:

[0118] 1) control mainboard control TCP drive motor through the drive TCP execution unit with horizontal transport mechanism with wafer into the hot plate inside heating hot core right above, when TCP into limit sensor trigger, control mainboard control TCP drive motor stop working, while need to lift the wafer;

[0119] 2) control mainboard control PIN drive motor through the drive PIN execution unit with PIN needle lift, when PIN needle to the upper limit position, PIN needle up limit sensor trigger, control mainboard control PIN drive motor stop working;

[0120] 3) control mainboard control TCP drive motor through the drive TCP execution unit with horizontal transport mechanism to withdraw from the hot plate, when horizontal transport mechanism returns to zero stop position, TCP return limit sensor trigger, control mainboard control TCP drive motor stop working;

[0121] 4) The control mainboard controls the PIN driving motor to drive the PIN execution unit to lower the PIN needle. When the PIN needle reaches the lower limit position, the PIN needle lowering limit sensor triggers, the control mainboard controls the PIN driving motor to stop working, and thus the wafer translation and lifting action is completed, and the heating core starts to heat the wafer.

[0122] Similarly, after the heating work is completed, the process of the entire device withdrawing the wafer from the hot plate includes the following stages:

[0123] 1) The control mainboard controls the PIN driving motor to drive the PIN execution unit to lift the PIN needle. When the PIN needle reaches the upper limit position, the PIN needle lifting limit sensor triggers, the control mainboard controls the PIN driving motor to stop working;

[0124] 2) The control mainboard controls the TCP driving motor to drive the TCP execution unit to drive the horizontal direction carrying mechanism to enter the hot plate and be directly above the heating core. When the TCP enters the limit sensor triggers, the control mainboard controls the TCP driving motor to stop working;

[0125] 3) The control mainboard controls the PIN driving motor to drive the PIN execution unit to lower the PIN needle. When the PIN needle reaches the lower limit position, the PIN needle lowering limit sensor triggers, the control mainboard controls the PIN driving motor to stop working;

[0126] 4) The control mainboard controls the TCP driving motor to drive the TCP execution unit to drive the horizontal direction carrying mechanism to withdraw from the hot plate. When the horizontal direction carrying mechanism returns to the zero return stop position, the TCP return limit sensor triggers, the control mainboard controls the TCP driving motor to stop working, and thus the wafer translation and lifting action is completed, and the wafer is withdrawn from the hot plate for easy taking.

[0127] Next, the working process of the system when the wafer is on the horizontal direction carrying mechanism and when the wafer is on the heating core of the hot plate will be described in detail:

[0128] When the wafer is on the horizontal direction carrying mechanism, the process of the PIN needle lifting the wafer includes five stages:

[0129] i. First stage of accelerated motion: the PIN needle starts at the lower limit position, and through acceleration and jerk parameters, S-curve acceleration is realized, so that the PIN driving motor accelerates smoothly;

[0130] ii. Maximum speed uniform motion: the PIN needle runs at a maximum speed for a distance to shorten the lifting time;

[0131] iii. deceleration: the speed is reduced to the minimum speed before the PIN pin touches the wafer;

[0132] iv. minimum speed uniform motion: the PIN pin moves steadily for a distance after it touches the wafer, so as to avoid a large collision with the wafer, similar to the action of gently picking up and putting down a hand;

[0133] v. second acceleration: the speed is increased after the wafer is stabilized on the PIN pin, and the PIN pin rises to the upper limit position, at which time the PIN pin upper limit sensor triggers, and the control board controls the PIN driving motor to stop working. The wafer has been stabilized on the PIN pin in the fourth stage, and the speed can be appropriately increased to make the whole picking process faster and improve work efficiency.

[0134] Specifically, when the wafer is on the horizontal direction carrying mechanism, the process of the PIN pin picking up the wafer (as shown in FIG. 2) is divided into five stages (as shown in FIG. 3): Figure 1 Figure 3

[0135] 1) S10~S11: S10 is the starting position of the PIN pin, that is, the position at which the first acceleration of the PIN pin starts, and the speed at this position is the minimum speed Min_Speed. S11 is the end position of the first acceleration of the PIN pin, that is, the position at which the first uniform motion of the PIN pin starts, and the speed at this position is the maximum speed Max_Speed. The motion of the PIN pin in this stage is as follows:

[0136] a = J * t ;

[0137] v = at = J * t 2 ;

[0138] wherein, a is the acceleration, J is the jerk, that is, the jerk, t is the running time, v is the speed;

[0139] if v ≥ Max_Speed, then v = Max_Speed; if a ≥ Max_Accel, then a = Max_Accel, wherein Max_Accel is the maximum acceleration;

[0140] ​​2) S11~S12: S12 is the position where the first uniform motion of the PIN ends, i.e. the position where the deceleration motion of the PIN starts. The speed at this position is still the maximum speed Max_Speed. The motion of the PIN in this stage is as follows:

[0141] v = Max_Speed;

[0142] 3) S12~S13: S13 is the position where the PIN contacts the wafer, i.e. the position where the deceleration motion of the PIN ends and the second uniform motion of the PIN starts. The speed at this position is the minimum speed Min_Speed. This stage uses the deceleration corresponding to the S0~S1 stage to control the deceleration, and the deceleration degree is set by the first deceleration acceleration percentage Decel1_Speed_Persent combined with the position where the deceleration motion ends. The motion of the PIN in this stage is as follows:

[0143] v = Max_Speed - ( at * Decel1_Speed_Persent);

[0144] If v ≤ Min_Speed, then v = Min_Speed; If the PIN does not drop to the minimum speed Min_Speed when it contacts the wafer, the position where the first uniform motion of the PIN ends needs to be adjusted to ensure that the speed of the PIN when it contacts the wafer is the minimum speed Min_Speed.

[0145] 4) S13~S14: S14 is the position where the second uniform motion of the PIN ends, i.e. the position where the second acceleration motion of the PIN starts. The speed at this position is still the minimum speed Min_Speed. In this stage, the PIN lifts the wafer to run a distance at the minimum speed Min_Speed. The motion of the PIN in this stage is as follows:

[0146] v = Min_Speed;

[0147] 5) S14~S15: S15 is the position where the second acceleration motion of the PIN ends, i.e. the stop position. At this time, the PIN_UP SENSOR is triggered, the PIN drive motor brakes, and the running is stopped. The motion of the PIN in this stage is as follows:

[0148] v = J * t 2 * Decel2_Speed_Persent;

[0149] Decel2_Speed_Persent is the second section deceleration percentage.

[0150] When the wafer is on the heating hot core of the hot plate, the process of the PIN pin lifting the wafer is divided into five stages:

[0151] i. Minimum speed uniform motion: the PIN pin starts at the lower limit position, and the control mainboard controls the PIN driving motor to run smoothly at the minimum speed. At this time, the PIN pin is in the heating hot core, and the distance between the PIN pin and the wafer is close (about 1 mm). The PIN pin cannot accelerate and decelerate to lift the PIN pin, so the PIN pin lifts the wafer at the minimum speed to ensure that the PIN pin does not collide with the wafer when it is lifted;

[0152] ii. Acceleration motion: after the PIN pin lifts the wafer, the S-curve acceleration is realized through the acceleration and jerk parameters, so that the PIN driving motor accelerates smoothly;

[0153] iii. Maximum speed uniform motion: the PIN pin runs at the maximum speed for a distance to shorten the lifting time;

[0154] iv. First section deceleration motion: the purpose is to make the PIN pin with the wafer quickly reduce to a certain speed to prepare for the subsequent second section deceleration motion;

[0155] v. Second section deceleration motion: the purpose is to make the PIN pin with the wafer move gradually to the minimum speed. When the PIN pin moves to the upper limit position, the PIN pin upper limit position sensor is triggered, and the control mainboard controls the PIN driving motor to stop working at this time.

[0156] Specifically, when the wafer is on the heating hot core of the hot plate, the process of the PIN pin lifting the wafer (as shown in Figure 2 ) is divided into five stages (as shown in Figure 4 ):

[0157] 1) S20~S21: S20 is the starting position of the PIN pin, that is, the position where the first section uniform motion of the PIN pin starts. The speed at this position is the minimum speed Min_Speed. S21 is the end position of the first section uniform motion of the PIN pin, that is, the position where the acceleration motion of the PIN pin starts. The speed at this position is still the minimum speed Min_Speed. The motion of the PIN pin in this stage is:

[0158] v = Min_Speed;

[0159] If the current running step number is 0.05 times the total number of preset single strokes, the uniform motion at the minimum speed Min_Speed is completed, and the wafer is slowly lifted.

[0160] 2) S21~S22: S22 is the position where the acceleration of the PIN ends, i.e. the position where the second stage of uniform motion of the PIN begins. The speed at this point is the maximum speed Max_Speed. The motion of the PIN at this stage is as follows:

[0161] a J t

[0162] v at J t 2

[0163] If V >= Max_Speed, then V = Max_Speed; if V >= Max_Accel, then a = Max_Accel; v v a a

[0164] 3) S22~S23: S23 is the position where the second stage of uniform motion of the PIN ends, i.e. the position where the first stage of deceleration of the PIN begins. The speed at this point is still the maximum speed Max_Speed. The motion of the PIN at this stage is as follows:

[0165] v V = Max_Speed;

[0166] 4) S23~S24: S24 is the position where the first stage of deceleration of the PIN ends, i.e. the position where the second stage of deceleration of the PIN begins. The speed at this point is:

[0167] v V = Max_Speed - Max_Accel*t*Decel1_Speed_Persent;

[0168] The motion of the PIN at this stage is as follows:

[0169] v V = Max_Speed - (Max_Accel*t*Decel1_Speed_Persent); at

[0170] If V <= Min_Speed, then V = Min_Speed; v v

[0171] ​​​​​​​​​​​​​​5) S24~S25: S25 is the position where the second stage of deceleration motion of the PIN pin ends, i.e. the stop position, the speed at this position is the minimum speed Min_Speed, slow stop is realized, and the motion of the PIN pin at this stage is as follows:

[0172] v = v −(Decel2_Speed_Persent) * Max_Speed; at

[0173] If Speed ≤ Min_Speed, then Speed = Min_Speed. v v

[0174] In addition, when the PIN pin descending / horizontal direction carrying mechanism enters the hot plate / horizontal direction carrying mechanism return, the TCP driving motor and PIN driving motor control logic in the three cases are the same, and the motion of the PIN pin and the horizontal direction carrying mechanism is divided into four stages (as shown in Figure 5 ), taking the PIN pin as an example:

[0175] 1) S30~S31: S30 is the starting position of the PIN pin, i.e. the position where the acceleration motion of the PIN pin starts, the speed at this position is the minimum speed Min_Speed, S31 is the position where the acceleration motion of the PIN pin ends, i.e. the position where the constant speed motion of the PIN pin starts, the speed at this position is the maximum speed Max_Speed, and the motion of the PIN pin at this stage is as follows:

[0176] a = J * t ;

[0177] v = at = J * t 2 ;

[0178] If Speed ≥ Max_Speed, then Speed = Max_Speed; if Speed ≥ Max_Accel, then Speed = Max_Accel. v v a a 2) S31~S32: S32 is the position where the constant speed motion of the PIN pin ends, i.e. the position where the first stage of deceleration motion of the PIN pin starts, the speed at this position is still the maximum speed Max_Speed, and the motion of the PIN pin at this stage is as follows:

[0179]

[0180] v = Max_Speed; ​​​​​​​

[0181] 3) S32~S33: S33 is the position of the first segment of the PIN needle deceleration motion end, that is, the position of the second segment of the PIN needle deceleration motion start, the speed here is:

[0182] v =Max_Speed-Decel1_Speed_Persent*t*Max_Accel;

[0183] The motion of the PIN needle in this stage is:

[0184] v =Max_Speed-(Decel1_Speed_Persent*t*Max_Accel); at

[0185] If v ≤Min_Speed, then v =Min_Speed;

[0186] 4) S33~S34: S34 is the position of the second segment of the PIN needle deceleration motion end, that is, the stop position, the speed here is the minimum speed Min_Speed, which realizes slow stop, and the motion of the PIN needle in this stage is:

[0187] v = v -(Decel2_Speed_Persent*t*Max_Accel); at

[0188] If v ≤Min_Speed, then v =Min_Speed.

[0189] In the technical scheme of the application, the closed-loop control process is completed by a control mainboard, and the control mainboard includes a CPU, a CAN communication module, a DI state monitoring module, a PWM signal generation module and a motor driving module.

[0190] The CAN communication module exchanges data with the PLC through the CAN communication mode.

[0191] The DI state monitoring module uses an isolated optocoupler to monitor the output signal of the limit sensor in real time, and sends each high and low level to the GPIO port of the corresponding CPU through an isolation circuit.

[0192] ​​The CPU calculates the speed and acceleration of the horizontal transport mechanism and PIN pins at each node according to the built-in algorithm, and counts the number of running steps during the operation of the drive motor. By comparing the number of running steps with the preset total number of steps for a single stroke, it collects the position information of the horizontal transport mechanism and PIN pins during the wafer transport process (the position information is automatically cleared when the limit sensor is triggered). At the same time, it receives the signal sent by the DI status monitoring module, dynamically monitors the status of the horizontal transport mechanism and PIN pins during the wafer transport process, collects status monitoring information, and controls the corresponding timer interrupt based on the movement of the horizontal transport mechanism and PIN pins at each node, as well as the position information and status monitoring information.

[0193] The PWM signal generation module sends a PWM signal to the STEP port of the motor drive module through an isolation chip under the action of a timer interrupt.

[0194] The motor drive module, under the control of the PWM signal, controls the TCP drive motor and the PIN drive motor to accelerate, decelerate and run at a constant speed at the corresponding positions.

[0195] In the technical solution of this application, both the horizontal transport mechanism and the PIN pins are driven by stepper motors. Combined with advanced and flexible program design and algorithm calculation, the motion mode and speed control of each action link can be subdivided and optimized to complete the entire translation and lifting action of the wafer with high quality. This avoids wafer offset and damage caused by strong vibration. At the same time, the smooth lifting action can prevent abnormal flow of photoresist on the wafer and ensure that the uniformity of the photoresist surface on the wafer does not change, which is beneficial to the subsequent wafer processing.

[0196] To better illustrate the technical effects of this application's technical solution, a detailed explanation is provided below with reference to a specific comparative experiment. In the comparative experiment, the values ​​of the various parameters for this application's technical solution are as follows:

[0197] Maximum speed Max_Speed ​​= 30000 (steps / s);

[0198] Minimum speed Min_Speed ​​= 1000 (steps / s);

[0199] Maximum acceleration Max_Accel = 50000 (steps / s) 2 );

[0200] Jerk = 50000 (steps / s) 3 );

[0201] The first stage of deceleration has an acceleration percentage of Decel1_Speed_Persent = 100 (steps / s). 2 );

[0202] Second deceleration acceleration percentage Decel2_Speed_Persent = 100 (step / s 2 )。

[0203] The traditional air valve driving mode and the driving mode provided by the technical scheme are compared and tested. The electronic three-axis gyroscope is placed on the wafer surface, and the wafer is lifted up and down by the two modes respectively. The detection results of the electronic three-axis gyroscope are as shown in Figure 6

[0204] Figure 6 The detection results obtained by the traditional air valve driving mode are larger on the left side of the middle. After the PIN pin contacts the wafer, the wafer is impacted and shaken greatly, with an offset of about 9 scales.

[0205] Figure 6 The detection results obtained by the driving mode provided by the technical scheme are on the right side of the middle. The maximum fluctuation is the moment when the PIN pin contacts the wafer, with an offset of only about 1-2 scales. The stability of the wafer is obviously improved.

[0206] The above embodiments are only used to illustrate the technical schemes of the present application, but not to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical schemes recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents. These modifications or replacements will not change the essence of the corresponding technical schemes beyond the spirit and scope of the technical schemes of the embodiments of the present application.​

Claims

1. A motor control method for improving wafer stability, characterized by: The position information of the PIN needle in the wafer carrying process is collected, the state of the PIN needle in the wafer carrying process is dynamically monitored, the state monitoring information is collected, and a PWM signal is generated based on the position information and the state monitoring information, so as to perform closed-loop control on the PIN driving motor; When the horizontal carrying mechanism drives the wafer to enter the heat plate and be above the heat core, the wafer needs to be jacked up, and the PIN driving motor is controlled according to the following process: The PIN needle is initially located at the lower limit position, and the PIN driving motor is controlled to accelerate smoothly; The PIN needle is driven to run at the maximum speed for a distance, so as to shorten the jacking time; The speed is reduced to the minimum speed before the PIN needle jacks up the wafer; The PIN needle is smoothly moved for a distance after jacking up the wafer; When the wafer is stable on the PIN needle, the speed is increased, and the PIN needle upper limit position sensor is triggered when the PIN needle moves to the upper limit position, at which time the PIN driving motor stops working; When the wafer is on the heat core in the heat plate and needs to be jacked up after heating, the PIN driving motor is controlled according to the following process: The PIN needle is initially located at the lower limit position, and the PIN driving motor is controlled to run smoothly at the minimum speed; The PIN needle is smoothly accelerated after jacking up the wafer; The PIN needle is driven to run at the maximum speed for a distance, so as to shorten the jacking time; Finally, the speed of the PIN needle is gradually reduced to the minimum speed, and the PIN needle upper limit position sensor is triggered when the PIN needle moves to the upper limit position, at which time the PIN driving motor stops working; The lower limit position and the upper limit position are determined by the state monitoring information, and the switching position of the PIN needle movement state is determined by the position information; When the wafer is on the heat core of the heat plate, the process of jacking up the wafer by the PIN needle is divided into five stages: 1) S20~S21: S20 is the starting position of the PIN needle, i.e. the position where the first uniform speed movement of the PIN needle starts, the speed at this position is the minimum speed Min_Speed, S21 is the end position of the first uniform speed movement of the PIN needle, i.e. the position where the acceleration movement of the PIN needle starts, the speed at this position is still the minimum speed Min_Speed, and the movement of the PIN needle in this stage is: v=Min_Speed; Wherein, v is the speed; If the current running step number is 0.05 times the total step number of the preset single stroke, the uniform speed movement at the minimum speed Min_Speed is completed, and the wafer is slowly lifted; 2) S21~S22: S22 is the end position of the acceleration movement of the PIN needle, i.e. the position where the second uniform speed movement of the PIN needle starts, the speed at this position is the maximum speed Max_Speed, and the movement of the PIN needle in this stage is: a=J*t; v = at = J * t 2 ; Wherein, a is the acceleration, J is the jerk, i.e. the jerk, and t is the running time; If v≥Max_Speed, then v=Max_Speed; if a≥Max_Accel, then a=Max_Accel, wherein Max_Accel is the maximum acceleration; 3) S22~S23: S23 is the position where the second section of the PIN needle ends its uniform motion, i.e. the position where the first section of the PIN needle starts its deceleration motion. The speed at this position is still the maximum speed Max_Speed. The motion of the PIN needle at this stage is as follows: v = Max_Speed; 4) S23~S24: S24 is the position where the first section of the PIN needle ends its deceleration motion, i.e. the position where the second section of the PIN needle starts its deceleration motion. The speed at this position is: v = Max_Speed - Max_Accel * t * Decel1_Speed_Persent; The motion of the PIN needle at this stage is as follows: v = Max_Speed - (at * Decel1_Speed_Persent); where Decel1_Speed_Persent is the acceleration percentage of the first section of deceleration. If v ≤ Min_Speed, then v = Min_Speed; 5) S24~S25: S25 is the position where the second section of the PIN needle ends its deceleration motion, i.e. the stop position. The speed at this position is the minimum speed Min_Speed, which realizes slow stop. The motion of the PIN needle at this stage is as follows: v = v - (at * Decel2_Speed_Persent); where Decel2_Speed_Persent is the acceleration percentage of the second section of deceleration. If v ≤ Min_Speed, then v = Min_Speed.

2. The motor control method for improving stability of a wafer according to claim 1, characterized by: When the wafer is on the horizontal direction carrying mechanism, the process of the PIN needle lifting the wafer is divided into five stages: 1) S10~S11: S10 is the starting position of the PIN needle, i.e. the position where the first section of the PIN needle starts its acceleration motion. The speed at this position is the minimum speed Min_Speed. S11 is the position where the first section of the PIN needle ends its acceleration motion, i.e. the position where the first section of the PIN needle starts its uniform motion. The speed at this position is the maximum speed Max_Speed. The motion of the PIN needle at this stage is as follows: a = J * t; v = at = J * t 2 ; where a is the acceleration, J is the jerk, i.e. the jerk, t is the running time, and v is the speed. If v ≥ Max_Speed, then v = Max_Speed; if a ≥ Max_Accel, then a = Max_Accel, where Max_Accel is the maximum acceleration. 2) S11~S12: S12 is the position where the first section of the PIN needle ends its uniform motion, i.e. the position where the PIN needle starts its deceleration motion. The speed at this position is still the maximum speed Max_Speed. The motion of the PIN needle at this stage is as follows: ​ 3) S12~S13: S13 is the position where the PIN pin contacts the wafer, i.e. the position where the deceleration of the PIN pin ends and the second uniform motion of the PIN pin starts, the speed at this position is the minimum speed Min_Speed, the deceleration control is performed in this stage by using the deceleration corresponding to the S10~S11 stage, and the deceleration degree is set by using the first deceleration acceleration percentage Decel1_Speed_Persent and the position where the deceleration ends, the motion of the PIN pin in this stage is as follows: v = Max_Speed - (at*Decel1_Speed_Persent); if v≤Min_Speed, then v = Min_Speed; if the PIN pin does not drop to the minimum speed Min_Speed when it contacts the wafer, the position where the first uniform motion of the PIN pin ends needs to be adjusted to ensure that the speed of the PIN pin when it contacts the wafer is the minimum speed Min_Speed; 4) S13~S14: S14 is the position where the second uniform motion of the PIN pin ends, i.e. the position where the second acceleration motion of the PIN pin starts, the speed at this position is still the minimum speed Min_Speed, the PIN pin lifts the wafer at the minimum speed Min_Speed for a distance, the motion of the PIN pin in this stage is as follows: v = Min_Speed; 5) S14~S15: S15 is the position where the second acceleration motion of the PIN pin ends, i.e. the stop position, at this time the PIN pin upper limit sensor is triggered, the PIN drive motor brake is stopped, the motion of the PIN pin in this stage is as follows: v = J * t 2 Decel2_Speed_Persent; wherein Decel2_Speed_Persent is the second deceleration acceleration percentage.

3. The motor control method for improving wafer stability according to claim 1, characterized by: When the PIN pin and the horizontal transport mechanism enter the hot plate and the horizontal transport mechanism returns, the control logic of the TCP drive motor and the PIN drive motor in the three cases is the same, the motion of the PIN pin and the horizontal transport mechanism is divided into four stages, the motion of the PIN pin in the four stages is as follows: 1) S30~S31: S30 is the starting position of the PIN pin, i.e. the position where the acceleration of the PIN pin starts, the speed at this position is the minimum speed Min_Speed, S31 is the position where the acceleration of the PIN pin ends, i.e. the position where the uniform motion of the PIN pin starts, the speed at this position is the maximum speed Max_Speed, the motion of the PIN pin in this stage is as follows: a = J*t; v = at = J * t 2 ; if v≥Max_Speed, then v = Max_Speed; if a≥Max_Accel, then a = Max_Accel; 2) S31~S32: S32 is the position where the uniform motion of the PIN pin ends, i.e. the position where the first deceleration of the PIN pin starts, the speed at this position is still the maximum speed Max_Speed, the motion of the PIN pin in this stage is as follows: v = Max_Speed; 3) S32~S33: S33 is the position of the first segment of the PIN needle deceleration motion end, that is, the position of the second segment of the PIN needle deceleration motion, the speed here is: v=Max_Speed-Decel1_Speed_Persent*t*Max_Accel; The motion of the PIN needle in this stage is: v=Max_Speed-(at*Decel1_Speed_Persent); If v<=Min_Speed, then v=Min_Speed; 4) S33~S34: S34 is the position of the second segment of the PIN needle deceleration motion end, that is, the stop position, the speed here is the minimum speed Min_Speed, which realizes slow stop, and the motion of the PIN needle in this stage is: v=v-(at*Decel2_Speed_Persent); If v<=Min_Speed, then v=Min_Speed.

4. The motor control method for improving wafer stability according to claim 1, characterized by: The closed-loop control process is completed by a control mainboard, and the control mainboard includes a CPU, a CAN communication module, a DI state monitoring module, a PWM signal generation module and a motor driving module; The CAN communication module exchanges data with the PLC through CAN communication mode; The DI state monitoring module uses an isolation optocoupler to monitor the output signal of the limit sensor in real time, and sends each high and low level to the GPIO port of the corresponding CPU through an isolation circuit; The CPU calculates the speed and acceleration of the horizontal conveying mechanism and the PIN needle at each node according to the built-in algorithm, and counts the running steps during the operation of the driving motor, compares the running steps with the preset total steps of a single stroke, collects the position information of the horizontal conveying mechanism and the PIN needle during wafer conveying, receives the signals sent by the DI state monitoring module, dynamically monitors the state of the horizontal conveying mechanism and the PIN needle during wafer conveying, collects the state monitoring information, and controls the corresponding timer interrupt based on the motion of the horizontal conveying mechanism and the PIN needle at each node, and the position information and state monitoring information; The PWM signal generation module sends PWM signals to the STEP port of the motor driving module through an isolation chip under the action of the timer interrupt; The motor driving module controls the TCP driving motor and the PIN driving motor to accelerate, decelerate and run at a constant speed at the corresponding position under the control of the PWM signal.

Images