Foreign matter detection method in coating process

Abstract

The invention discloses a method for detecting foreign matters in a coating process. The method comprises the following steps: acquiring a first brightness value and a second brightness value obtained by detecting the surface of a base material according to a preset detection period in a coating process; calculating a brightness change rate according to the first brightness value, the second brightness value and the duration of the detection period; if the brightness change rate is larger than a preset change rate threshold value, it is determined that foreign matter exists on the surface of the base material; wherein the foreign matters are micron-sized foreign matters. According to the technical scheme, whether foreign matters exist on the surface of the base material is judged based on the brightness change rate, and micron-sized foreign matters can be accurately detected.

Description

Technical Field

[0001] The present invention relates to the technical field of foreign matter detection, and in particular to a method for detecting foreign matter in a coating process. Background Art

[0002] After spraying a uniform layer of glue on the substrate surface, a foreign object detection sensor is used to detect foreign objects. This sensor consists of a transmitter and a receiver. The transmitter transmits a laser beam to the receiver, forming a stable laser detection optical path; the receiver monitors the laser signal intensity in real time. When a foreign object is present on the substrate surface, it blocks the laser transmission path, reducing the light flux received by the receiver and the corresponding brightness value. The sensor transmits the real-time detected brightness value to the PLC (Programmable Logic Controller) via an analog signal. In the PLC program, the system determines the presence of a foreign object based on whether the detected brightness value is less than a set threshold. However, existing technology can only detect larger foreign objects. Summary of the Invention

[0003] The present invention provides a method for detecting foreign matter in a coating process, which determines whether foreign matter exists on the surface of a substrate based on the brightness change rate and can accurately detect micron-level foreign matter.

[0004] According to one aspect of the present invention, a method for detecting foreign matter in a coating process is provided, the method comprising:

[0005] Obtaining a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process;

[0006] Calculating a brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period;

[0007] If the brightness change rate is greater than a preset change rate threshold, it is determined that foreign matter exists on the surface of the substrate; wherein the foreign matter is a micron-sized foreign matter.

[0008] The technical solution of the embodiments of the present invention obtains first and second brightness values obtained by inspecting the substrate surface during the coating process according to a preset detection cycle. Based on the first and second brightness values and the duration of the detection cycle, the brightness change rate is calculated and judged to determine the presence of foreign matter on the substrate surface. This technical solution, which determines the presence of foreign matter on the substrate surface based on the brightness change rate, can accurately detect micron-sized foreign matter, resolving the problem that existing technologies can only detect larger foreign matter.

[0009] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 This is a flow chart of a method for detecting foreign matter in a coating process provided in accordance with the first embodiment of the present invention;

[0012] Figure 2 A schematic diagram of a foreign matter detection process during a coating process provided in a second embodiment of the present invention;

[0013] Figure 3 A flowchart of another method for detecting foreign matter during a coating process provided in Example 3 of the present invention;

[0014] Figure 4 A schematic diagram of another foreign matter detection process during a coating process provided in embodiment 4 of the present invention. DETAILED DESCRIPTION

[0015] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0016] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0017] Example 1

[0018] Figure 1This is a flow chart of a method for detecting foreign matter during a coating process according to a first embodiment of the present invention. This embodiment is applicable to detecting whether there is foreign matter on the surface of a substrate during the coating process. Figure 1 As shown, the method includes:

[0019] S110 , obtaining a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process.

[0020] In this solution, coating refers to spraying a layer of glue evenly on the surface of the substrate. The substrate refers to the material that serves as the basic support or core carrier during the manufacturing process and is the main part or underlying structure of the product.

[0021] Among them, the detection cycle can be set according to the foreign matter detection requirements during the coating process.

[0022] Furthermore, the substrate surface is detected at the start time of the detection period to obtain a first brightness value; and the substrate surface is detected at the end time of the detection period to obtain a second brightness value.

[0023] In this embodiment, a sensor can be used to detect the substrate surface during the coating process according to a preset detection period to obtain a first brightness value and a second brightness value. The first brightness value and the second brightness value are then transmitted to a computing device, which acquires the first brightness value and the second brightness value obtained by detecting the substrate surface during the coating process according to the preset detection period. The computing device can be a programmable logic controller or a computer.

[0024] S120. Calculate a brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period.

[0025] In this solution, the first brightness value, the second brightness value, and the duration of the detection period may be weighted and combined to calculate the brightness change rate.

[0026] Optionally, calculating the brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period includes:

[0027] Calculating a difference between the first brightness value and the second brightness value;

[0028] The brightness change rate is obtained by dividing the difference between the first brightness value and the second brightness value by the duration of the detection period.

[0029] Specifically, the brightness change rate is calculated using the following formula:

[0030] Brightness change rate=(second brightness value−first brightness value) / duration of the detection period.

[0031] By calculating the brightness change rate, it is possible to determine whether there is foreign matter on the substrate surface based on the brightness change rate, thereby improving the accuracy of foreign matter detection.

[0032] Optionally, the duration of the detection period is set according to the distance the substrate surface moves during the coating process; wherein, the distance the substrate surface moves during the coating process is 0.1 mm.

[0033] In this solution, the detection period is set to a time when the substrate surface moves 0.1 mm during the coating process, wherein the substrate surface moves along the horizontal axis during the coating process.

[0034] Furthermore, the first brightness value and the second brightness value are collected every 0.1 mm during the coating process.

[0035] By setting the duration of the detection cycle, micron-level foreign matter can be accurately detected.

[0036] S130: If the brightness change rate is greater than a preset change rate threshold, it is determined that there is foreign matter on the surface of the substrate; wherein the foreign matter is micron-sized foreign matter.

[0037] The change rate threshold can be set according to the foreign matter detection requirements during the coating process.

[0038] Specifically, when the brightness change rate is greater than a preset change rate threshold, it is determined that foreign matter exists on the surface of the substrate.

[0039] Furthermore, when the rate of change is less than or equal to a preset rate of change threshold, it is determined that no foreign matter exists on the surface of the substrate.

[0040] The technical solution of the embodiments of the present invention obtains first and second brightness values obtained by inspecting the substrate surface during the coating process according to a preset inspection cycle. The brightness change rate is then calculated based on the first and second brightness values and the duration of the inspection cycle. This brightness change rate is then used to determine the presence of foreign matter on the substrate surface. By implementing this technical solution, foreign matter can be accurately detected even at the micron level by determining the presence of foreign matter on the substrate surface based on the brightness change rate.

[0041] Example 2

[0042] Figure 2 This is a schematic diagram of a foreign body detection process during a coating process provided by the second embodiment of the present invention. The relationship between this embodiment and the above embodiment is a detailed supplement to the foreign body detection process. Figure 2 As shown, the method includes:

[0043] S210. Acquire, based on a programmable logic controller, a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection period during the coating process; wherein the scanning period of the programmable logic controller is 500 microseconds.

[0044] In this embodiment, the programmable logic controller uses a programmable memory to store instructions for performing operations such as logical operations, sequential control, timing, counting and arithmetic operations, and controls various types of mechanical equipment or production processes through digital or analog input and output.

[0045] Specifically, the scanning period of the programmable logic controller is set to 500 microseconds. When the substrate is running horizontally, the brightness value can be detected at a shorter distance.

[0046] Optionally, a programmable logic controller is used to obtain a first brightness value and a second brightness value obtained by a foreign object detection and measurement device detecting the surface of the substrate according to a preset detection cycle during the coating process; wherein the foreign object detection and measurement device includes a foreign object detection and measurement transmitter and a foreign object detection and measurement receiver; the foreign object detection and measurement transmitter and the foreign object detection and measurement receiver transmit data through analog communication.

[0047] In this solution, the foreign object detection and measurement transmitter can be the transmitter in the sensor; the foreign object detection and measurement receiver can be the receiver in the sensor. The transmitter transmits a laser beam to the receiver, forming a stable laser detection optical path. The receiver monitors the laser signal intensity in real time. When foreign matter is present on the substrate surface, it blocks the laser transmission path, reducing the light flux received by the receiver and the corresponding brightness value.

[0048] Furthermore, the foreign object detection and measurement transmitting end and the foreign object detection and measurement receiving end transmit data through analog communication.

[0049] Specifically, the foreign object detection measurement transmitting end and the foreign object detection measurement receiving end detect the substrate surface at the start time of the detection cycle to obtain a first brightness value; and the foreign object detection measurement transmitting end and the foreign object detection measurement receiving end detect the substrate surface at the end time of the detection cycle to obtain a second brightness value.

[0050] In this solution, the first brightness value and the second brightness value are detected by the foreign object detection and measurement transmitting end and the foreign object detection and measurement receiving end, and the first brightness value and the second brightness value are sent to the programmable logic controller.

[0051] For example, assuming that the first brightness value obtained by detecting the substrate surface within 0.1 mm is 1 and the second brightness value is 2, the brightness change rate is calculated; brightness change rate = (second brightness value 2 - first brightness value 1) / 0.1.

[0052] Furthermore, data is collected every time the horizontal axis moves 0.1mm. Because the maximum horizontal axis speed is 150mm / s and the PLC scan period is 500 microns, (0.5 / 1000)*150=0.075mm. Since 0.075mm<0.1mm, the PLC can stably read the position before and after each 0.1mm advance of the horizontal axis and simultaneously read the brightness value at the corresponding position. This means that micron-level foreign objects can be accurately detected based on the brightness change rate within 0.1mm.

[0053] By using analog communication to transmit data between the foreign object detection and measurement transmitter and the foreign object detection and measurement receiver, the circuit transmission speed approaches the speed of light, and the signal propagation speed is significantly improved.

[0054] S220: Calculate a brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period.

[0055] S230: If the brightness change rate is greater than a preset change rate threshold, it is determined that there is foreign matter on the surface of the substrate; wherein the foreign matter is micron-sized foreign matter.

[0056] The change rate threshold can be set according to the foreign matter detection requirements during the coating process.

[0057] Specifically, when the brightness change rate is greater than a preset change rate threshold, it is determined that foreign matter exists on the surface of the substrate.

[0058] Furthermore, when the rate of change is less than or equal to a preset rate of change threshold, it is determined that no foreign matter exists on the surface of the substrate.

[0059] Optionally, a preset alarm action is executed based on a programmable logic controller; wherein the alarm action includes at least one of an audible and visual alarm, a remote notification, a device linkage, and a data recording; the audible and visual alarm is to emit audible and visual signals through a buzzer and a warning light; the remote notification is to send an alarm message to a preset terminal through network communication; the data recording is to store the time, location and brightness value data of the foreign object detection event in a database.

[0060] In this solution, when foreign matter is detected on the surface of the substrate, a preset alarm action is executed based on the programmable logic controller.

[0061] Specifically, when the alarm action is an audible and visual alarm, an audible and visual signal is emitted through a buzzer and a warning light; when the alarm action is a remote notification, an alarm message is sent to a preset terminal through network communication; when the alarm action is a data record, the time, location and brightness value data of the foreign object detection event are stored in a database.

[0062] The coating quality can be effectively improved by executing preset alarm actions through the programmable logic controller.

[0063] The technical solution of the embodiment of the present invention is to obtain the first brightness value and the second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process based on a programmable logic controller, and then calculate the brightness change rate based on the first brightness value, the second brightness value and the duration of the detection cycle, and judge the brightness change rate to determine whether there is foreign matter on the surface of the substrate. When it is determined that there is foreign matter on the surface of the substrate, a preset alarm action is executed based on the programmable logic controller. By executing this technical solution, the presence of foreign matter on the surface of the substrate can be judged based on the brightness change rate, and micron-level foreign matter can be accurately detected. The execution of the preset alarm action by the programmable logic controller can effectively improve the coating quality.

[0064] Example 3

[0065] Figure 3 This is a flow chart of another method for detecting foreign matter in a coating process provided by the third embodiment of the present invention. The relationship between this embodiment and the above embodiment is a supplement to the foreign matter detection process. Figure 3 As shown, the method includes:

[0066] S310 , obtaining a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process.

[0067] S320: Calculate a brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period.

[0068] S330: If the brightness change rate is greater than a preset change rate threshold, it is determined that there is foreign matter on the surface of the substrate; wherein the foreign matter is micron-sized foreign matter.

[0069] S340 , obtaining a third brightness value corresponding to the starting position and a fourth brightness value corresponding to the ending position when the substrate surface moves a preset target distance; and obtaining all brightness change rates within the target distance range.

[0070] The preset target distance can be set according to the requirements for detecting foreign objects during the coating process. For example, the target distance can be set to 20 mm.

[0071] Specifically, the programmable logic controller obtains the third brightness value corresponding to the starting position and the fourth brightness value corresponding to the ending position when the substrate surface moves a preset target distance; and obtains all brightness change rates within the target distance range.

[0072] S350: If the difference between the fourth brightness value and the third brightness value is greater than a preset first threshold, and all brightness change rates within the target distance range show a continuous increasing trend, it is determined that foreign matter exists on the lower surface of the substrate.

[0073] In this embodiment, the preset first threshold value can be set according to the foreign matter detection requirement during the coating process.

[0074] Specifically, when the difference between the fourth brightness value and the third brightness value is greater than the first threshold, and all brightness change rates within the target distance show a continuous increasing trend, it is determined that the foreign matter exists on the lower surface of the substrate.

[0075] S360 : Determine, in the brightness value set within the target distance interval, a fifth brightness value and a sixth brightness value obtained by detecting the substrate surface according to a preset detection cycle.

[0076] The fifth brightness value is the brightness value at the start of the detection period; and the sixth brightness value is the brightness value at the end of the detection period.

[0077] In this embodiment, the fifth brightness value and the sixth brightness value are multiple. For example, if the target distance is set to 20 mm and the detection cycle duration is set to 0.1 mm movement of the substrate surface during the coating process, the fifth brightness value and the sixth brightness value are multiple.

[0078] Specifically, in the brightness value set of the target distance interval, the programmable logic controller receives the fifth brightness value and the sixth brightness value obtained by the foreign object detection and measurement device detecting the substrate surface according to a preset detection cycle during the coating process.

[0079] S370: If the difference between the sixth brightness value and the fifth brightness value is smaller than a preset second threshold, it is determined that foreign matter exists on the upper surface of the substrate.

[0080] In this embodiment, the preset threshold value can be set according to the foreign matter detection requirements during the coating process.

[0081] Specifically, within the target distance, when the difference between the sixth brightness value and the fifth brightness value is less than the second threshold, it is determined that the foreign matter exists on the upper surface of the substrate.

[0082] The technical solution of the embodiment of the present invention obtains the first brightness value and the second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process, and then calculates the brightness change rate based on the first brightness value, the second brightness value and the duration of the detection cycle, and judges the brightness change rate to determine whether there is foreign matter on the surface of the substrate. When it is determined that there is foreign matter on the surface of the substrate, it is judged whether the foreign matter exists on the upper surface of the substrate or the lower surface of the substrate. By implementing this technical solution, the presence of foreign matter on the surface of the substrate is judged based on the brightness change rate, which can not only accurately detect foreign matter at the micron level, but also determine whether the foreign matter is on the upper surface or the lower surface of the substrate.

[0083] Example 4

[0084] Figure 4 This is a schematic diagram of another foreign body detection process during the coating process provided by the fourth embodiment of the present invention. The relationship between this embodiment and the above embodiment is a detailed supplement to the foreign body detection process. Figure 4 As shown, the method includes:

[0085] S410 , obtaining a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process.

[0086] S420: Calculate a brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period.

[0087] S430: If the brightness change rate is greater than a preset change rate threshold, it is determined that there is foreign matter on the surface of the substrate; wherein the foreign matter is micron-sized foreign matter.

[0088] S440: storing the brightness change rate in a server based on a programmable logic controller.

[0089] Specifically, during foreign object detection, the programmable logic controller (PLC) stores the collected brightness change rate data in real time into a 6,850-element array. Once a substrate is inspected and ready for discharge, the system uploads the array data to the CIM (Computer Integrated Manufacturing) system and ultimately stores it on a server.

[0090] S450: In response to the data display operation, the brightness change rate is displayed in the form of a curve graph.

[0091] Furthermore, the operator can first pull data from the server and convert it into a curve graph. Through the curve graph, the operator can view the foreign matter detection change rate of each substrate and observe the surface flatness of each substrate.

[0092] The technical solution of the embodiment of the present invention obtains first and second brightness values obtained by inspecting the substrate surface during the coating process according to a preset inspection cycle. Based on the first and second brightness values and the duration of the inspection cycle, the brightness change rate is calculated and judged to determine whether foreign matter is present on the substrate surface. The brightness change rate is then stored in a server. By implementing this technical solution, the brightness change rate can be used to accurately determine whether micron-sized foreign matter is present on the substrate surface, and the brightness change rate is stored for easy subsequent review.

[0093] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0094] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for detecting foreign matter during a coating process, characterized in that: include: Obtaining a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process; Calculating a brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period; If the brightness change rate is greater than a preset change rate threshold, it is determined that foreign matter exists on the surface of the substrate; wherein the foreign matter is a micron-sized foreign matter.

2. The method according to claim 1, characterized in that Obtaining a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process, including: A first brightness value and a second brightness value obtained by detecting the surface of the substrate during the coating process according to a preset detection cycle are obtained based on a programmable logic controller; wherein the scanning cycle of the programmable logic controller is 500 microseconds.

3. The method according to claim 2, characterized in that Acquiring, based on a programmable logic controller, a first brightness value and a second brightness value obtained by detecting the surface of the substrate according to a preset detection cycle during the coating process, including: Based on the programmable logic controller, a first brightness value and a second brightness value are obtained by the foreign object detection and measurement device detecting the surface of the substrate according to a preset detection cycle during the coating process; wherein, the foreign object detection and measurement device includes a foreign object detection and measurement transmitting end and a foreign object detection and measurement receiving end; the foreign object detection and measurement transmitting end and the foreign object detection and measurement receiving end transmit data through analog communication.

4. The method according to claim 1, wherein Calculating a brightness change rate according to the first brightness value, the second brightness value, and the duration of the detection period includes: Calculating a difference between the first brightness value and the second brightness value; The brightness change rate is obtained by dividing the difference between the first brightness value and the second brightness value by the duration of the detection period.

5. The method according to claim 1 or 4, characterized in that The duration of the detection cycle is set according to the distance the substrate surface moves during the coating process; wherein, the distance the substrate surface moves during the coating process is 0.1 mm.

6. The method according to claim 1, characterized in that After determining that foreign matter exists on the surface of the substrate, the method further includes: Execute preset alarm actions based on a programmable logic controller; wherein, the alarm action includes at least one of an audible and visual alarm, a remote notification, a device linkage, and data recording; the audible and visual alarm emits audible and visual signals through a buzzer and a warning light; the remote notification sends an alarm message to a preset terminal through network communication; the data recording stores the time, location, and brightness value data of the foreign object detection event in a database.

7. The method according to claim 1, characterized in that After determining that foreign matter exists on the surface of the substrate, the method further includes: Obtaining a third brightness value corresponding to a starting position and a fourth brightness value corresponding to an ending position when the substrate surface moves a preset target distance; and obtaining all brightness change rates within the target distance range; If the difference between the fourth brightness value and the third brightness value is greater than a preset first threshold, and all brightness change rates within the target distance range show a continuous increasing trend, it is determined that foreign matter exists on the lower surface of the substrate.

8. The method according to claim 7, characterized in that After determining that foreign matter exists on the surface of the substrate, the method further includes: In the brightness value set of the target distance interval, determining a fifth brightness value and a sixth brightness value obtained by detecting the surface of the substrate according to a preset detection cycle; If the difference between the sixth brightness value and the fifth brightness value is smaller than a preset second threshold, it is determined that foreign matter exists on the upper surface of the substrate.

9. The method according to claim 1, characterized in that After determining that foreign matter exists on the surface of the substrate, the method further includes: The brightness change rate is stored in a server based on a programmable logic controller.

10. The method according to claim 9, characterized in that Storing the brightness change rate in a server based on a programmable logic controller includes: In response to the data display operation, the brightness change rate is displayed in the form of a curve graph.

Images