Motor control method for improving wafer stability

Abstract

The invention relates to semiconductor equipment, in particular to a motor control method for improving wafer stability, which comprises the following steps of: collecting position information of a PIN in a wafer carrying process, dynamically monitoring the state of the PIN in the wafer carrying process, collecting state monitoring information, generating a PWM (Pulse Width Modulation) signal based on the position information and the state monitoring information, and sending the PWM signal to a controller; performing closed-loop control on the PIN driving motor; according to the technical scheme provided by the invention, the defect that the wafer is difficult to translate and lift stably when the wafer is heated in the prior art can be effectively overcome.

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 PIN is lifted by controlling the air inlet and outlet of the cylinder through the electromagnetic valve, which has the advantages of simple control and can realize speed switching by adjusting the frequency and air pressure of the air inlet and 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 jacking mechanism, which mainly uses a double-acting cylinder to drive the jacking mechanism to lift.

[0004] However, the PIN is lifted by the cylinder, which has a big disadvantage, that is, the speed control flexibility is insufficient during the lifting of the PIN, 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 when the wafer is heated.

[0006] To achieve the above purpose, the present application realizes the following technical scheme: A motor control method for improving wafer stability, collecting position information of the PIN during wafer carrying, dynamically monitoring the state of the PIN during wafer carrying, collecting state monitoring information, and generating a PWM signal based on the position information and the state monitoring information, and performing closed-loop control on the PIN driving motor; 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 jacked up, and the PIN driving motor is controlled according to the following process: The PIN initially locates at the lower limit position, and the PIN driving motor is controlled to accelerate smoothly; Drive the PIN needle at maximum speed for a certain distance to shorten the lifting time; Reduce the speed to the minimum before the PIN needle hits the wafer; After the PIN needle hits the wafer, it moves steadily for a distance; When the wafer is stable on the PIN needle, the speed is increased. When the PIN needle moves to the upper limit position, the PIN needle rising limit sensor is triggered, and the PIN drive motor stops working. When the wafer is heated on the heat core inside the hot plate and needs to be lifted after the heating work is completed, the PIN drive motor is controlled according to the following process: The PIN needle is initially located at the lower limit position, controlling the PIN drive motor to run smoothly at the minimum speed; After the PIN needle hits the wafer, it accelerates smoothly; Drive the PIN needle at maximum speed for a certain distance to shorten the lifting time; Finally, the PIN needle gradually reduces its speed to the minimum speed. When the PIN needle moves to the upper limit position, the PIN needle rising limit sensor is triggered, and the PIN drive motor stops working. Among them, 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.

[0007] Preferably, when the wafer is on a horizontal transport mechanism, the process of PIN pin pushing the wafer is divided into five stages: 1) S10~S11: S10 is the starting position of the PIN needle, that is, the position where the first stage of the PIN needle's accelerated motion begins. The speed here is the minimum speed Min_Speed. S11 is the position where the first stage of the PIN needle's accelerated motion ends, that is, the position where the first stage of the PIN needle's uniform motion begins. The speed here is the maximum speed Max_Speed. The movement of the PIN needle in this stage is as follows: a = J * t ; v = at = J * t 2 ; in, a is the acceleration, J is the acceleration, i.e. the jerk, t is the running time, v for speed; like v ≥Max_Speed, then v =Max_Speed; if a ≥Max_Accel, thena = Max_Accel, wherein Max_Accel is the maximum acceleration; 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: v = Max_Speed; 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: v = Max_Speed - ( at * Decel1_Speed_Persent); 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; 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, the PIN lifts the wafer at the minimum speed Min_Speed in this stage, the motion of the 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 ends, i.e. the stop position, at this time the PIN upper limit sensor is triggered, the PIN driving motor brakes and stops running, the motion of the PIN in this stage is as follows: v = J * t 2 * Decel2_Speed_Persent; wherein Decel2_Speed_Persent is the second deceleration speed percentage.

[0008] Preferably, the process of the PIN pin lifting the wafer is divided into five stages when the wafer is on the heating core of the hot plate: 1) S20~S21: S20 is the starting position of the PIN pin, i.e. the position where the first 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 uniform motion of the PIN pin, i.e. 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: v = Min_Speed; 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; 2) S21~S22: S22 is the end position of the acceleration motion of the PIN pin, i.e. the position where the second 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: a = J * t ; v = at = J * t 2 ; If v ≥ Max_Speed, then v = Max_Speed; if a ≥ Max_Accel, then a = Max_Accel; 3) S22~S23: S23 is the end position of the second uniform motion of the PIN pin, i.e. the position where the first deceleration motion 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: v = Max_Speed; 4) S23~S24: S24 is the end position of the first deceleration motion of the PIN pin, i.e. the position where the second deceleration motion of the PIN pin starts, the speed at this position is: v = Max_Speed - Max_Accel * t * Decel1_Speed_Persent; The motion of the PIN pin in this stage is: v = Max_Speed - ( at*Decel1_Speed_Persent) ; If v ≤ Min_Speed, then v = Min_Speed; 5) S24~S25: S25 is the position where the second stage of deceleration motion of the PIN ends, i.e. the stop position, the speed here is the minimum speed Min_Speed, slow stop is realized, and the motion of the PIN in this stage is as follows: v = v - at *Decel2_Speed_Persent) ; If v ≤ Min_Speed, then v = Min_Speed.

[0009] Preferably, when the PIN descending / horizontal direction carrying mechanism enters the hot plate / horizontal direction carrying mechanism returns, the TCP driving motor and PIN driving motor control logic in the three cases are the same, and the motion of the PIN and the horizontal direction carrying mechanism is divided into four stages, taking the PIN as an example: 1) S30~S31: S30 is the starting position of the PIN, i.e. the position where the acceleration motion of the PIN starts, the speed here is the minimum speed Min_Speed, S31 is the position where the acceleration motion of the PIN ends, i.e. the position where the constant speed motion of the PIN starts, the speed here is the maximum speed Max_Speed, and the motion of the 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 constant speed motion of the PIN ends, i.e. the position where the first stage of deceleration motion of the PIN starts, the speed here is still the maximum speed Max_Speed, and the motion of the PIN in this stage is as follows: v = Max_Speed; 3) S32~S33: S33 is the position where the first deceleration movement of the PIN needle ends, that is, the position where the second deceleration movement of the PIN needle begins. The speed here is: v =Max_Speed-Max_Accel*t*Decel1_Speed_Persent; The movement of the PIN needle in this stage is as follows: v =Max_Speed-( at *Decel1_Speed_Persent); like v ≤Min_Speed, then v =Min_Speed; 4) S33~S34: S34 is the position where the second deceleration motion of the PIN needle ends, that is, the stop position. The speed here is the minimum speed Min_Speed, achieving a slow stop. The movement of the PIN needle in this stage is: v = v -( at *Decel2_Speed_Persent); like v ≤Min_Speed, then v =Min_Speed.

[0010] Preferably, the closed-loop control process is completed by a control mainboard, which includes a CPU, a CAN communication module, a DI status monitoring module, a PWM signal generating module and a motor driving module; CAN communication module, which exchanges data with PLC via CAN communication; The DI status 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 corresponding CPU GPIO port through an isolation circuit; The CPU calculates the speed and acceleration of the horizontal transport mechanism and the PIN needle at each node based on a built-in algorithm, counts the number of running steps during the operation of the drive motor, collects the position information of the horizontal transport mechanism and the PIN needle during the wafer transport process by comparing the running step count with the preset total number of steps per single stroke, and simultaneously receives the signal sent by the DI status monitoring module to dynamically monitor the status of the horizontal transport mechanism and the PIN needle during the wafer transport process, collects the status monitoring information, and controls the corresponding timer interrupt based on the movement of the horizontal transport mechanism and the PIN needle at each node, as well as the position information and status monitoring information; PWM signal generating module, under the action of timer interrupt, sends PWM signal to STEP port of motor driving module through isolation chip; Motor driving module, under the control of PWM signal, controls TCP driving motor and PIN driving motor to accelerate, decelerate and run at uniform speed in corresponding position.

[0011] Compared with the prior art, the motor control method for improving wafer stability provided by the application adopts step motor driving for horizontal direction carrying mechanism and 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 wafer, avoids strong vibration to cause wafer deviation and damage, at the same time, the stable lifting action can prevent abnormal flow of photoresist on wafer, ensures that the photoresist surface uniformity of wafer will not change, and is beneficial to wafer processing in later period. BRIEF DESCRIPTION OF DRAWINGS

[0012] 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 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 without creative labor on the basis of these drawings.

[0013] Figure 1 PIN needle top wafer schematic diagram when wafer is on the horizontal direction carrying mechanism in the application; Figure 2 PIN needle top wafer schematic diagram when wafer is on the heating hot core of hot plate in the application; Figure 3 PIN needle top wafer schematic diagram when wafer is on the horizontal direction carrying mechanism in the application; Figure 4 PIN needle top wafer schematic diagram when wafer is on the heating hot core of hot plate in the application; Figure 5 PIN needle top wafer schematic diagram when wafer is on the heating hot core of hot plate in the application; Figure 6 PIN needle top wafer schematic diagram when wafer is on the heating hot core of hot plate in the application; Figure 7 PIN needle top wafer schematic diagram when wafer is on the heating hot core of hot plate in the application; Figure 8 PIN needle top wafer schematic diagram when wafer is on the heating hot core of hot plate in the application; Figure 7The schematic diagram of the structure of the middle wafer conveying device after the hot plate is removed; Figure 9 For the purpose of the present application Figure 7 The schematic diagram of the partial structure of the middle wafer conveying device; 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; Figure 11 For the purpose of the present application Figure 10 The schematic diagram of the bottom structure; Figure 7 In the present application 1, horizontal conveying mechanism; 2, TCP driving motor; 3, TCP return limit sensor; 4, PIN needle; 5, PIN driving motor; 6, horizontal conveying 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 hot core. DETAILED DESCRIPTION

[0014] 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 with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part 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.

[0015] 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 combination with specific examples.

[0016] The specific process includes: collecting position information of the PIN needle in the wafer conveying process, dynamically monitoring the state of the PIN needle in the wafer conveying process, collecting 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; When the horizontal conveying mechanism drives the wafer to enter the inside of the hot plate directly above the heating hot 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 to shorten the jacking-up time; The speed is reduced to the minimum speed before the PIN needle jacks up the wafer; The PIN needle is moved smoothly for a distance after jacking up the wafer; When the wafer is stable on the PIN needle, the speed is increased, and when the PIN needle moves to the upper limit position, the PIN needle upper limit sensor is triggered, at which time the PIN drive motor stops working; When the wafer is heated on the heat core inside the hot plate, and needs to be lifted after the heating work is completed, the PIN drive motor is controlled according to the following process: 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; After the PIN needle is lifted to the wafer, it is accelerated smoothly; The PIN needle is driven to run at the maximum speed for a distance to shorten the lifting time; Finally, the speed of the PIN needle is gradually reduced to the minimum speed, and when the PIN needle moves to the upper limit position, the PIN needle upper limit sensor is triggered, at which time the PIN drive motor stops working; Wherein, 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.

[0017] Figures 7-11 The figure is a structure schematic diagram of the wafer carrying device in the application, and the names and functions of the numbers in the figure are as follows: 1-horizontal carrying mechanism: a device for horizontally carrying wafers, and each time the wafer falls on its plane; 2-TCP drive motor: a step motor for driving the horizontal carrying mechanism to move horizontally; 3-TCP return limit sensor: a limit sensor for returning the horizontal carrying mechanism to zero and stopping, which triggers the sensor after the horizontal carrying mechanism moves to the specified position, and the TCP drive motor stops immediately to ensure consistent stop position; 4-PIN needle: a device for vertically carrying wafers, and the PIN device has three ceramic pins, which lift the wafer to complete the lifting and lowering action through the pins; 5-PIN drive motor: a step motor for driving the PIN needle to move vertically; 6-horizontal carrying mechanism belt roller: a device for cooperating with the TCP drive motor and driving the horizontal carrying mechanism to move in combination with the belt; 7-PIN lead screw: a device for driving the PIN needle to move up and down, and the lower end has a gear connected with the PIN drive motor through the belt (as shown in Figure 10 and Figure 11 ); 8-PIN needle lower limit sensor: a limit sensor for the PIN needle to descend, which triggers the sensor after the PIN needle descends to the specified position, and the PIN drive motor stops immediately to ensure consistent stop position; 9-PIN needle up limit sensor: PIN needle up limit sensor, PIN needle up to the specified position, trigger sensor, PIN drive motor will stop immediately, to ensure consistent stop position; 10-TCP into limit sensor: for horizontal direction carrying mechanism into the heat plate inside the limit sensor, horizontal direction carrying mechanism to the specified position, trigger sensor, TCP drive motor will stop immediately, to ensure consistent stop position; 11-Heating hot core: for heating wafer device, ceramic material, the whole wafer carrying heat plate is in the process of taking on the heating hot core.

[0018] The whole device will be placed on the heating hot core wafer process includes the following stages: 1) control the main board control TCP drive motor through the drive TCP execution unit with horizontal direction carrying mechanism with wafer into the heat plate inside the heating hot core right above, when the TCP into limit sensor trigger, control the main board control TCP drive motor stop working, while the need to lift the wafer; 2) control the main board control PIN drive motor through the drive PIN execution unit with PIN needle lifting, PIN needle to the upper limit position, PIN needle up limit sensor trigger, control the main board control PIN drive motor stop working; 3) control the main board control TCP drive motor through the drive TCP execution unit with horizontal direction carrying mechanism to withdraw from the heat plate, when the horizontal direction carrying mechanism returns to zero stop position, TCP return limit sensor trigger, control the main board control TCP drive motor stop working; 4) control the main board control PIN drive motor through the drive PIN execution unit with PIN needle down, PIN needle to the lower limit position, PIN needle down limit sensor trigger, control the main board control PIN drive motor stop working, thus complete a wafer translation, lifting action, heating hot core starts to heat the wafer.

[0019] Similarly, after the completion of the heating work, the whole device will be taken out of the heat plate wafer process includes the following stages: 1) control the main board control PIN drive motor through the drive PIN execution unit with PIN needle lifting, PIN needle to the upper limit position, PIN needle up limit sensor trigger, control the main board control PIN drive motor stop working; 2) control the main board control TCP drive motor through the drive TCP execution unit with horizontal direction carrying mechanism with wafer into the heat plate inside the heating hot core right above, when the TCP into limit sensor trigger, control the main board control TCP drive motor stop working; 3) The control mainboard controls the PIN driving motor to drive the PIN to descend through the driving PIN execution unit. When the PIN reaches the lower limit position, the PIN descending limit sensor triggers, and the control mainboard controls the PIN driving motor to stop working; 4) The control mainboard controls the TCP driving motor to drive the horizontal direction carrying mechanism to withdraw the hot plate through the driving TCP execution unit. When the horizontal direction carrying mechanism returns to the zero return stop position, the TCP return limit sensor triggers, and the control mainboard controls the TCP driving motor to stop working. Thus, the wafer is withdrawn from the hot plate, which is convenient for taking.

[0020] The working process of the system under the following two conditions of the wafer on the horizontal direction carrying mechanism and the wafer on the heating core of the hot plate will be described in detail below in combination with the structure of the wafer carrying device: When the wafer is on the horizontal direction carrying mechanism, the process of the PIN lifting the wafer is divided into five stages: i. First acceleration movement: the PIN starts at the lower limit position, and through the acceleration and jerk parameters, the S-curve acceleration is realized, so that the PIN driving motor accelerates smoothly; ii. Maximum speed uniform motion: the PIN is driven at the maximum speed for a distance to shorten the lifting time; iii. Deceleration movement: the speed is reduced to the minimum speed before the PIN lifts the wafer; iv. Minimum speed uniform motion: after the PIN lifts the wafer, it moves smoothly for a distance, which aims to avoid a large collision with the wafer, similar to the action of gently picking up and putting down by hand; v. Second acceleration movement: when the wafer is stable on the PIN, the speed is increased. When the PIN moves to the upper limit position, the PIN upper limit sensor triggers, and the control mainboard controls the PIN driving motor to stop working. After the fourth stage, the wafer has been stable on the PIN, and the speed can be appropriately increased to make the whole taking process faster and improve the work efficiency.

[0021] Specifically, when the wafer is on the horizontal direction carrying mechanism, the process of the PIN lifting the wafer (as shown in Figure 1 ) is divided into five stages (as shown in Figure 3 ): 1) S10~S11: S10 is the starting position of the PIN, i.e. the position where the first acceleration movement of the PIN starts. The speed here is the minimum speed Min_Speed. S11 is the end position of the first acceleration movement of the PIN, i.e. the position where the first uniform motion of the PIN starts. The speed here is the maximum speed Max_Speed. The movement of the PIN in this stage is: a= J * t ; v = at = J * t 2 ; in, a is the acceleration, J is the acceleration, i.e. the jerk, t is the running time, v for speed; like 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 uniform motion of the PIN needle ends, that is, the position where the PIN needle decelerates and the speed here is still the maximum speed Max_Speed. The movement of the PIN needle in this stage is: v =Max_Speed; 3) S12~S13: S13 is the position where the PIN needle contacts the wafer, that is, the position where the PIN needle deceleration movement ends and the position where the second uniform speed movement of the PIN needle begins. The speed here is the minimum speed Min_Speed. In this stage, the deceleration control is performed using the deceleration corresponding to the S0~S1 stage. The deceleration degree is set based on the acceleration percentage Decel1_Speed_Persent of the first deceleration and the position where the deceleration movement ends. The movement of the PIN needle in this stage is as follows: v =Max_Speed-( at *Decel1_Speed_Persent); like v ≤Min_Speed, then v =Min_Speed; If the PIN needle does not drop to the minimum speed Min_Speed ​​when it contacts the wafer, it is necessary to adjust the position where the PIN needle's first uniform motion ends to ensure that the speed of the PIN needle when it contacts the wafer is the minimum speed Min_Speed; 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 wafer is lifted by the PIN needle at the minimum speed Min_Speed for a distance, the motion of the PIN needle in this stage is as follows: v = Min_Speed; 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_UP SENSOR is triggered, the PIN driving motor brakes and stops running, the motion of the PIN needle in this stage is as follows: v = Min_Speed; J t 2 *Decel2_Speed_Persent; wherein Decel2_Speed_Persent is the acceleration percentage of the second section of deceleration.

[0022] When the wafer is on the heating hot core of the hot plate, the process of the PIN needle lifting the wafer is divided into five stages: i. Minimum speed uniform motion: the PIN needle starts at the lower limit position, the control main board controls the PIN driving motor to run smoothly at the minimum speed, at this time, the PIN needle is in the heating hot core, the distance between the PIN needle and the wafer is close (about 1mm), the PIN needle cannot accelerate and decelerate to lift the PIN needle, therefore, the PIN needle lifts the wafer at the minimum speed to ensure that there is no large collision when the PIN needle lifts the wafer; ii. Accelerated motion: after the PIN needle lifts the wafer, the S-curve acceleration is realized through the acceleration and jerk parameters, so that the PIN driving motor accelerates smoothly; iii. Maximum speed uniform motion: the PIN needle runs at the maximum speed for a distance to shorten the lifting time; iv. First section of deceleration motion: the purpose is to enable the PIN needle to quickly reduce to a certain speed with the wafer, so as to prepare for the subsequent second section of deceleration motion; v. Second section of deceleration motion: the purpose is to enable the PIN needle to gradually reduce the speed to the minimum speed with the wafer, when the PIN needle moves to the upper limit position, the PIN needle upper limit position sensor is triggered, at this time, the control main board controls the PIN driving motor to stop working.

[0023] Specifically, when the wafer is on the heating hot core of the hot plate, the process of the PIN needle lifting the wafer (as shown in Figure 2 is divided into five stages (as shown in Figure 4 ): ​1) S20~S21: S20 is the starting position of the PIN needle, that is, the position where the first section of the PIN needle uniform motion begins. The speed here is the minimum speed Min_Speed. S21 is the position where the first section of the PIN needle uniform motion ends, that is, the position where the PIN needle accelerated motion begins. The speed here is still the minimum speed Min_Speed. The movement of the PIN needle in this stage is: v =Min_Speed; If the current running step number is 0.05 times the preset single-stroke total step number, the uniform motion at the minimum speed Min_Speed ​​is completed, and the wafer is slowly lifted; 2) S21~S22: S22 is the position where the PIN needle's accelerated motion ends, that is, the position where the PIN needle's second uniform motion begins. The speed here is the maximum speed Max_Speed. The movement of the PIN needle in this stage is: a = J * t ; v = at = J * t 2 ; like v ≥Max_Speed, then v =Max_Speed; if a ≥Max_Accel, then a =Max_Accel; 3) S22~S23: S23 is the position where the second stage of uniform motion of the PIN needle ends, that is, the position where the first stage of deceleration motion of the PIN needle begins. The speed here is still the maximum speed Max_Speed. The motion of the PIN needle in this stage is: v =Max_Speed; 4) S23~S24: S24 is the position where the first deceleration movement of the PIN needle ends, that is, the position where the second deceleration movement of the PIN needle begins. The speed here is: v =Max_Speed-Max_Accel*t*Decel1_Speed_Persent; The movement of the PIN needle in this stage is as follows: v =Max_Speed-( at *Decel1_Speed_Persent); like v ≤Min_Speed, thenv = Min_Speed; 5) S24~S25: S25 is the position where the second stage of deceleration motion of the PIN ends, i.e. the stop position, the speed at this position is the minimum speed Min_Speed, slow stop is achieved, and the motion of the PIN at this stage is as follows: v = v − (Decel2_Speed_Persent) * Decel2_Speed_Persent); at If Speed ≤ Min_Speed, then Speed = Min_Speed. v v In addition, when the PIN descending / horizontal direction carrying mechanism enters the hot plate / horizontal direction carrying mechanism returns, the TCP driving motor and PIN driving motor control logic in the three cases are the same, and the motion of the PIN and the horizontal direction carrying mechanism is divided into four stages (as shown in

[0024] 1) S30~S31: S30 is the starting position of the PIN, i.e. the position where the acceleration motion of the PIN starts, the speed at this position is the minimum speed Min_Speed, S31 is the position where the acceleration motion of the PIN ends, i.e. the position where the constant speed motion of the PIN starts, the speed at this position is the maximum speed Max_Speed, and the motion of the PIN at this stage is as follows: Figure 5 a = J * t ; v = at = J * t 2 ; 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 ends, i.e. the position where the first stage of deceleration motion of the PIN starts, the speed at this position is still the maximum speed Max_Speed, and the motion of the PIN at this stage is as follows: = Max_Speed; v 3) S32~S33: S33 is the position where the first stage of deceleration motion of the PIN ends, i.e. the position where the second stage of deceleration motion of the PIN starts, the speed at this position is: ​​​​​​​​v = Max_Speed - Max_Accel * t * Decel1_Speed_Persent; The motion of the PIN needle in this stage is as follows: v = Max_Speed - ( at * Decel1_Speed_Persent); If v ≤ Min_Speed, then v = Min_Speed; 4) S33-S34: S34 is the position where the second stage of deceleration of the PIN needle ends, that is, the stop position, and the speed here is the minimum speed Min_Speed, achieving slow stop. The motion of the PIN needle in this stage is as follows: v = v - ( at * Decel2_Speed_Persent); If v ≤ Min_Speed, then v = Min_Speed.

[0025] In the technical solution of the application, the closed-loop control process is completed by a control mainboard, which 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 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. 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. By comparing the running steps with the preset total steps per stroke, the position information of the horizontal conveying mechanism and the PIN needle during wafer conveying is collected (the position information is automatically cleared when the limit sensor is triggered). At the same time, the CPU 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 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 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. Motor driving module, under the control of PWM signal, controls TCP driving motor and PIN driving motor to accelerate, decelerate and run at uniform speed in corresponding positions.

[0026] In the technical scheme of the application, the horizontal conveying mechanism and the PIN are both driven by stepping motors, and in combination with advanced and flexible program design and algorithm operation, the motion mode and speed control of each action link can be subdivided and optimized, and the whole translation and lifting action of the wafer can be completed with high quality, so that wafer deviation and damage caused by strong vibration are avoided, meanwhile, the stable lifting action can prevent abnormal flow of photoresist on the wafer, ensure that the photoresist uniformity of the wafer will not change, and is beneficial to the wafer processing in the later stage.

[0027] In order to better illustrate the technical effect of the technical scheme of the application, a specific comparative experiment is described in detail as follows. In the comparative experiment, the values of the parameters of the technical scheme of the application are as follows: Maximum speed Max_Speed = 30000 (steps / s); Minimum speed Min_Speed = 1000 (steps / s); Maximum acceleration Max_Accel = 50000 (steps / s 2 ); Jerk = 50000 (steps / s 3 ); First segment deceleration acceleration percentage Decel1_Speed_Persent = 100 (steps / s 2 ); Second segment deceleration acceleration percentage Decel2_Speed_Persent = 100 (steps / s 2 ).

[0028] The traditional air valve driving mode and the driving mode provided by the technical scheme of the application are compared and tested, an electronic three-axis gyroscope is placed on the wafer surface, and the wafer is lifted up and down by using the two modes respectively, and the detection results of the electronic three-axis gyroscope are as shown in Figure 6 .

[0029] Figure 6 The left side of the middle has larger fluctuation, which is the detection result obtained by using the traditional air valve driving mode, after the PIN contacts the wafer, the wafer is impacted and has larger shaking, about 9 scales of deviation.

[0030] Figure 6 The right side of the middle is the detection result obtained by using the driving mode provided by the technical scheme of the application, the maximum fluctuation is the moment when the PIN contacts the wafer, and the deviation is only about 1-2 scales, and the wafer stability is obviously improved.

[0031] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those ordinarily skilled in the art should understand: the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced equivalently; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions 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 the PWM signal is generated based on the position information and the state monitoring information, so as to control the PIN driving motor in a closed loop; When the horizontal direction carrying mechanism drives the wafer to enter the heat plate and the heat core is directly above the heat plate, 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 heated on the heat plate and the heating work is completed, 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 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.

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 jacking up the wafer by the PIN needle is divided into five stages: 1) S10~S11: S0 is the starting position of the PIN needle, that is, 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, that is, 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: a = J * t ； v = at = J * t 2 ； wherein a is the acceleration, J is the jerk, i.e. the jolt, t is the running time, 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 constant speed movement of the PIN needle ends, that is, the position where the deceleration movement of the PIN needle starts, the speed here is still the maximum speed Max_Speed, and the movement of the PIN needle in this stage is: v = Max_Speed; 3) S12~S13: S13 is the position where the PIN needle contacts the wafer, that is, the position where the deceleration movement of the PIN needle ends and the second constant speed movement of the PIN needle starts, the speed here is the minimum speed Min_Speed, the deceleration degree is set by the first deceleration acceleration percentage Decel1_Speed_Persent in combination with the position where the deceleration movement ends, and the movement of the PIN needle in this stage is: v =Max_Speed-( at *Decel1_Speed_Persent); If v ≤ Min_Speed, then v = Min_Speed; if the PIN needle does not drop to the minimum speed Min_Speed when it contacts the wafer, the position at which the first uniform motion of the PIN needle ends needs to be adjusted to ensure that the speed of the PIN needle when it contacts the wafer is the minimum speed Min_Speed. 4) S13~S14: S14 is the position where the second segment of the PIN needle ends uniform motion, i.e. the position where the second segment of the PIN needle starts accelerated motion, the speed at this position is still the minimum speed Min_Speed, in this stage, the wafer is lifted by the PIN needle at the minimum speed Min_Speed for a distance, the motion of the PIN needle in this stage is as follows: v = Min_Speed; 5) S14~S15: S15 is the position where the second segment 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: v = J * t 2 *Decel2_Speed_Persent; Wherein, Decel2_Speed_Persent is the acceleration percentage of the second segment deceleration.

3. The motor control method for improving stability of a wafer according to claim 1, characterized by: 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: 1) S20~S21: S20 is the starting position of the PIN needle, i.e. the position where the first segment 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 segment 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: v = Min_Speed; If the current running step number is 0.05 times the total step number of the preset single stroke, the uniform motion at the minimum speed Min_Speed is completed, and the wafer is slowly lifted; 2) S21~S22: S22 is the position where the second segment of the PIN needle starts uniform motion, i.e. the position where the PIN needle ends accelerated motion, the speed at this position is the maximum speed Max_Speed, the motion of the PIN needle 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; 3) S22~S23: S23 is the position where the second segment of the PIN needle ends uniform motion, i.e. the position where the first segment of the PIN needle starts deceleration motion, the speed at this position is still the maximum speed Max_Speed, the motion of the PIN needle in this stage is as follows: v = Max_Speed; 4) S23~S24: S24 is the position where the first segment of the PIN needle ends deceleration motion, i.e. the position where the second segment of the PIN needle starts deceleration motion, the speed at this position is: v = Max_Speed - Max_Accel * t * Decel1_Speed_Persent; The motion of the PIN needle in this stage is as follows: v =Max_Speed-( at *Decel1_Speed_Persent); If v ≤ Min_Speed, then v = Min_Speed; 5) S24~S25: S25 is the position where the second segment of the PIN needle ends 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 in this stage is as follows: 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: When the PIN needle descending / horizontal direction carrying mechanism enters the hot plate / horizontal direction carrying mechanism returns, the control logic of the TCP driving motor and the PIN driving motor in the three cases is 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: 1) S30~S31: S30 is the initial position of the PIN, that is, the position where the acceleration of the PIN starts, the speed at this position is the minimum speed Min_Speed, S31 is the end position of the acceleration of the PIN, that is, the position where the uniform motion of the PIN starts, the speed at this position is the maximum speed Max_Speed, the motion of the 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 end position of the uniform motion of the PIN, that is, the position where the first stage of deceleration 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: v = Max_Speed; 3) S32~S33: S33 is the end position of the first stage of deceleration of the PIN, that is, the position where the second stage of deceleration of the PIN starts, the speed at this position is: v = Max_Speed - Max_Accel * t * Decel1_Speed_Persent; The motion of the PIN in this stage is as follows: v =Max_Speed-( at *Decel1_Speed_Persent); If v ≤ Min_Speed, then v = Min_Speed; 4) S33~S34: S34 is the end position of the second stage of deceleration of the PIN, that is, the stop position, the speed at this position is the minimum speed Min_Speed, which realizes slow stop, the motion of the PIN in this stage is as follows: v = v at *Decel2_Speed_Persent);​ If v ≤ Min_Speed, then v = Min_Speed.

5. The motor control method for improving wafer stability according to claim 1, wherein: The closed-loop control process is completed by a control mainboard, 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 the 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 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 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 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 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.

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