Dispensing track planning method, system and storage medium for OLED module packaging

Abstract

The application discloses a dispensing track planning method, system and storage medium for OLED module packaging, the method comprising: decomposing a frame glue track into a plurality of straight line segments and corner segments, obtaining the length of each straight line segment and the turning angle and turning radius of each corner segment; sequentially calculating the exponential decay of the structure parameter in the straight line segment and the exponential recovery in the corner segment from the starting point of the track along the path travel direction to obtain the structure parameter value at the entrance of each corner; and respectively correcting the deceleration starting distance and the minimum passing speed of each corner according to the structure parameter value, and splicing with the speed of each straight line segment to generate a speed curve of the frame glue track. The application can adapt the corner speed control to the current thixotropic state of the glue, reduce the accumulation of glue at the corner, and improve the consistency of the frame glue line width and the quality of the OLED module packaging.

Description

Technical Field

[0001] This application relates to the field of OLED dispensing control technology, specifically to a dispensing trajectory planning method, system, and storage medium for OLED module packaging. Background Technology

[0002] OLED modules are sensitive to moisture and oxygen, typically requiring the application of encapsulation adhesive around the perimeter of the display panel. This adhesive, in conjunction with a cover plate, forms a sealed structure. During the dispensing process, the dispensing equipment controls the movement of the dispensing head according to a preset trajectory and speed, while the dispensing device provides dispensing pressure to the dispensing needle. To reduce adhesive buildup caused by the decrease in speed when the dispensing head passes through corners, existing dispensing trajectory planning generally sets a deceleration starting position and a minimum passing speed based on the corner's angle and turning radius.

[0003] However, the frame adhesive used for OLED module encapsulation is typically a high-viscosity thixotropic adhesive. When this type of adhesive is subjected to continuous shearing within the needle, its effective viscosity gradually decreases with increasing shearing time; after the shearing force weakens, its viscosity recovers with a certain lag. Therefore, even if different corners have the same geometry, the flow state of the adhesive at each corner may differ due to variations in the length of the preceding straight segment, the running speed, and the cumulative shearing time.

[0004] Existing methods typically apply the same deceleration parameters to corners of the same shape, making it difficult to reflect the continuous changes in adhesive state along the dispensing path. This can easily lead to wider adhesive lines, localized overflow, or uneven adhesive distribution in subsequent corner areas. Furthermore, during the dispensing initiation phase, the viscosity of the stationary adhesive is high, and using a fixed dispensing pressure may result in a narrower adhesive line at the beginning, affecting the consistency of the frame adhesive ring width and encapsulation reliability. Therefore, existing technologies still need to address the lack of coordinated control between the changes in the state of thixotropic adhesives and the dispensing trajectory speed and dispensing pressure. Summary of the Invention

[0005] This application provides a dispensing trajectory planning method, system, and storage medium for OLED module packaging, in order to at least solve some of the technical problems existing in the related technologies described above.

[0006] According to a first aspect of the embodiments of this application, a dispensing trajectory planning method for OLED module packaging is provided, comprising: The frame adhesive trajectory is decomposed into several straight line segments and corner segments, and the length of each straight line segment and the turning angle and turning radius of each corner segment are obtained. Starting from the trajectory's starting point and moving along the path, the changes in structural parameters are calculated alternately for each straight segment and each corner segment to obtain the values ​​of the structural parameters at each corner entrance. The structural parameters characterize the degree of integrity of the adhesive's thixotropic structure, which decays exponentially within each straight segment, with the decay rate determined by the adhesive's failure time constant. The structural parameters recover exponentially within each corner segment, with the recovery rate determined by the adhesive's recovery time constant. Based on the values ​​of the structural parameters at each corner entrance, the deceleration starting distance and minimum passing speed of each corner are corrected respectively. The lower the value of the structural parameter, the greater the deceleration starting distance and the higher the minimum passing speed of the corresponding corner. By splicing the corrected deceleration starting distance and minimum passing speed at each corner with the speed of each straight segment, a speed curve of the frame rubber trajectory is generated.

[0007] As an optional approach, the values ​​of the structural parameters at the exit of each straight segment are obtained by exponentially decaying the values ​​of the structural parameters at the entrance of the straight segment; the degree of decay of the exponential decay is determined by the length of the straight segment, the planning speed of the straight segment, and the failure time constant; the longer the straight segment or the lower the planning speed of the straight segment, the lower the value of the structural parameters at the exit.

[0008] As an optional approach, the values ​​of the structural parameters at the exit of each corner segment are obtained by exponentially recovering the values ​​of the structural parameters at the entrance of the corner segment; the degree of recovery by exponential recovery is determined by the passage time of the corner segment and the recovery time constant; the recovery time constant is greater than the failure time constant; the passage time of each corner segment is estimated based on the deceleration start distance of the corner segment, the speed of the straight section before entering the corner segment, the minimum passage speed of the corner segment, the turning radius of the corner segment, and the turning angle of the corner segment; when calculating the structural parameters for the first time, the deceleration start distance and the minimum passage speed are taken as basic values ​​determined by the corner geometry.

[0009] As an optional approach, the correction method for the deceleration starting distance at each corner is as follows: a correction increment is superimposed on the basic deceleration starting distance determined by the corner's turning angle and turning radius. The correction increment is determined based on the deviation of the structural parameter value at the corner entrance from the reference structural parameter value. The correction method for the minimum passing speed at each corner is as follows: the basic minimum passing speed determined by the corner's turning angle and turning radius is multiplied by a correction coefficient related to the deviation. The reference structural parameter value is determined in a calibration experiment.

[0010] As an optional approach, the correction increment and the correction coefficient are calibrated in the following way: after the long straight segment and after the short straight segment, respectively, a dispensing test is performed at a corner with the same turning angle and the same turning radius. The glue line width of the two corner areas is measured, and the correction increment and the correction coefficient are calculated based on the difference between the two glue line widths and the target glue line width.

[0011] As an optional solution, it also includes compensating for the dispensing pressure of the initial transition section of the frame adhesive trajectory; the initial transition section is the path interval from the starting point of the trajectory to the value of the structural parameter decaying to the steady-state value; within the initial transition section, the dispensing pressure at each position is adjusted according to the ratio of the effective viscosity corresponding to the structural parameter at each position to the steady-state effective viscosity; the compensated dispensing pressure curve is issued and executed synchronously with the speed curve.

[0012] As an alternative, the effective viscosity is linearly determined between the zero-shear viscosity and the equilibrium viscosity after sufficient shearing of the adhesive based on the value of the structural parameter; the zero-shear viscosity and the equilibrium viscosity after sufficient shearing are obtained by measuring with a rotational rheometer, and the length of the initial transition section is determined by the product of the dispensing speed and the failure time constant.

[0013] As an alternative approach, the failure time constant is obtained through a step shear experiment using a rotational rheometer: a constant shear rate is applied to the adhesive from a static state, the viscosity decreases over time, and the failure time constant is obtained by fitting an exponential decay function; the recovery time constant is obtained through a step recovery experiment using a rotational rheometer: the adhesive is reduced from a high shear steady state to a low shear state, the viscosity recovers over time, and the recovery time constant is obtained by fitting an exponential recovery function.

[0014] According to a second aspect of the embodiments of this application, a dispensing trajectory planning system for OLED module packaging is also provided, comprising: The trajectory decomposition module is used to decompose the frame adhesive trajectory into several straight line segments and corner segments, and obtain the length of each straight line segment and the turning angle and turning radius of each corner segment. The structural parameter calculation module is used to calculate the changes in structural parameters alternately for each straight segment and each corner segment along the path travel direction from the trajectory starting point. The structural parameters, namely the integrity of the thixotropic structure of the adhesive, decay exponentially within each straight segment, with the decay rate determined by the adhesive's failure time constant. The structural parameters recover exponentially within each corner segment, with the recovery rate determined by the adhesive's recovery time constant. The module obtains the values ​​of the structural parameters at each corner entrance. The corner parameter correction module is used to correct the deceleration start distance and minimum passing speed of each corner according to the values ​​of the structural parameters at each corner entrance. The lower the value of the structural parameter, the greater the deceleration start distance and the higher the minimum passing speed of the corresponding corner. The speed curve generation module is used to stitch together the deceleration starting distance and minimum passing speed after each corner correction with the speed of each straight segment to generate the speed curve of the frame rubber trajectory.

[0015] According to a third aspect of the embodiments of this application, a computer-readable storage medium is provided, which, when an executable computer program in the storage medium is executed by a processor, enables the implementation of the method described in the first aspect.

[0016] This application characterizes the structural failure process of adhesive under continuous shear and the recovery process after shear weakening by dividing the adhesive path into straight and corner segments and introducing structural parameters that continuously change with the dispensing path. This allows the thixotropic state of the adhesive at each corner entrance to be determined based on the preceding path length, running speed, and passage time. Based on this, the deceleration starting distance and minimum passage speed are adjusted according to the structural parameters at each corner entrance, avoiding localized adhesive accumulation caused by setting uniform deceleration parameters only based on corner angle and turning radius. This ensures that corners at different path locations can achieve speed control adapted to the current adhesive flow state. Simultaneously, adjusting the dispensing pressure based on the change in effective adhesive viscosity relative to steady-state effective viscosity within the initial transition section reduces insufficient adhesive dispensing during the transition from a static state to a stable shear state. This improves the consistency of the adhesive line width throughout the entire adhesive path, reduces the probability of corner overflow, narrow initial adhesive line, and inadequate local sealing, and allows for adjustment of planning parameters under different adhesive and path specifications using rheological test parameters and a small amount of calibration data.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Furthermore, no embodiment in this disclosure is required to achieve all the effects described above. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0019] Figure 1 This is a flowchart illustrating a dispensing trajectory planning method for OLED module packaging, provided as an embodiment of the present disclosure.

[0020] Figure 2 A flowchart illustrating the calculation of changes in structural parameters provided in this embodiment of the disclosure.

[0021] Figure 3 This is a schematic block diagram of a dispensing trajectory planning system for OLED module packaging, provided as an embodiment of the present disclosure.

[0022] Figure 4 This is a schematic block diagram of an electronic device provided in an embodiment of the present disclosure. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0024] This embodiment provides a dispensing trajectory planning method for OLED module encapsulation, applicable to OLED module manufacturing lines using frame adhesive encapsulation. In this process, the dispensing equipment applies sealing frame adhesive along the periphery of the panel, forming a closed loop to prevent moisture and oxygen intrusion during subsequent pressing with the encapsulation cover plate. The dispensing equipment includes a dispensing head that can move along a horizontal plane, a dispensing needle mounted on the dispensing head, a pressure dispensing system that supplies adhesive to the needle, and a motion controller. The motion controller controls the operation of each axis servo motor according to a pre-planned speed curve, and the pressure dispensing system provides dispensing pressure to the needle according to a pre-set pressure value. The frame adhesive used for OLED encapsulation is a high-viscosity thixotropic fluid. Under continuous shear, the effective viscosity gradually decreases, and after the shear weakens, the effective viscosity gradually recovers, with the recovery rate significantly slower than the decrease rate. This method tracks the thixotropic state of the adhesive by introducing a structural parameter that continuously evolves along the path in the trajectory speed planning. Based on this, the deceleration parameters at each corner are differentiated and the dispensing pressure at the beginning segment is compensated.

[0025] The implementation process of the method described in this application will be described in detail below with reference to specific embodiments. It should be noted that this embodiment is only used to explain this application and is not intended to limit the scope of protection of this application. Conventional adjustments or substitutions of each step by those skilled in the art without departing from the concept of this application should be included in the scope of protection of this application.

[0026] Please see Figure 1 , Figure 1 This is a flowchart of a dispensing trajectory planning method for OLED module packaging according to an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes the following steps: S1, decompose the frame adhesive trajectory into several straight line segments and corner segments, and obtain the length of each straight line segment and the turning angle and turning radius of each corner segment; S2, starting from the trajectory starting point and moving along the path, alternately calculate the changes in structural parameters for each straight segment and each corner segment; the structural parameters, representing the integrity of the thixotropic structure of the adhesive, decay exponentially within each straight segment, with the decay rate determined by the adhesive's failure time constant; the structural parameters recover exponentially within each corner segment, with the recovery rate determined by the adhesive's recovery time constant; thus, obtain the values ​​of the structural parameters at each corner entrance; S3, Based on the values ​​of the structural parameters at each corner entrance, the deceleration starting distance and minimum passing speed of each corner are corrected respectively. The lower the value of the structural parameter, the greater the deceleration starting distance and the higher the minimum passing speed of the corresponding corner. S4, the deceleration starting distance and minimum passing speed after each corner correction are spliced ​​with the speed of each straight segment to generate the speed curve of the frame rubber trajectory.

[0027] In some embodiments, step S1 is illustrated using a frame adhesive coating scenario for a 6.7-inch OLED panel as an example. The frame adhesive trajectory is approximately rectangular, with a long side length of, for example, 155 mm, a short side length of, for example, 72 mm, four 90-degree corners, and a turning radius of, for example, 0.5 mm. The zero-shear viscosity of the frame adhesive used is, for example, 100,000 mPa·s, the equilibrium viscosity after sufficient shearing is, for example, 35,000 mPa·s, and the dispensing speed is, for example, 150 mm / s.

[0028] Before execution, the frame adhesive trajectory is decomposed into several straight line segments and corner segments. The length of each straight line segment and the turning angle and turning radius of each corner segment are obtained. The complete coordinate sequence of the frame adhesive trajectory is extracted from the panel design data and decomposed in an alternating manner of straight line segments and corner segments, which will not be elaborated here. Taking the above panel as an example, the trajectory contains 4 straight lines and 4 90-degree corners in sequence, starting from the bottom left end and moving clockwise. The lengths of each straight line segment are 155mm, 72mm, 155mm, and 72mm, respectively. The turning angle of each corner is 90 degrees (i.e., (rad), with a turning radius of 0.5mm.

[0029] In some embodiments, for step S2, a scalar is defined. This characterizes the degree of integrity of the thixotropic structure of the glue at the current path position, and is called the structure parameter in rheology; among them, This indicates that the adhesive is in its complete structural state after being fully settled, at which point its effective viscosity is highest. This indicates that the microstructure has been completely sheared and destroyed, and the effective viscosity has been reduced to a minimum. When taking any value between 0 and 1, the effective viscosity Determine by the following formula: ; in Zero shear viscosity, in mPa·s; The equilibrium viscosity after full shearing is expressed in mPa·s. Provided by the adhesive supplier or measured at low shear rates using a rotational rheometer. The viscosity was continuously measured using a rotational rheometer at a constant shear rate similar to the actual shear rate within the needle until it stabilized, and then read. For example, the adhesive used in the aforementioned panel... mPa·s, mPa·s.

[0030] It is understandable that this linear relationship is a simplified constitutive model widely used in thixotropic fluid research. Its applicability is based on the condition that the adhesive exhibits a linear thixotropic response within the current needle shear rate range, meaning that the effective viscosity and structural parameters are linearly related. For adhesive systems that deviate from a linear response, the mapping relationship between η and λ can be calibrated using piecewise linear or nonlinear interpolation, which will not be elaborated upon here.

[0031] in, The evolution along the path is controlled by two time constants: the destruction time constant. Characterizing the structural parameters of the glue under constant shear. From initial value decay to The time required to recover approximately 36.8% of the initial value, in seconds; recovery time constant. Characterized by the cessation of shearing The time, in seconds, taken for the structure to recover from its current value to 1.0, and to approximately 36.8% of its original value, compared to the complete structure. For highly thixotropic Dam adhesives... For example, take 0.3 to 0.8 seconds. For example, take 2 to 5 seconds. Usually These two time constants are 4 to 10 times the original value. The method for obtaining these two time constants will be explained in the calibration section later and will not be repeated here. The examples in the following steps use... s、 s.

[0032] Please see Figure 2 , Figure 2 A flowchart illustrating the calculation of changes in structural parameters provided in an embodiment of this disclosure is shown, such as... Figure 2 As shown in box 201, the structural parameters decay exponentially within the straight segment. During the glue dispensing process in the straight segment, the glue is continuously sheared within the needle channel. Decreasing exponentially, let the length of a certain straight line segment be... (Unit: mm), planned speed is (Unit: mm / s), structural parameters at the inlet are: Then the structural parameters at the outlet for: ; Index Term The physical meaning is the ratio of the sustained shear time experienced by the glue in the straight line segment to the failure time constant. The larger this ratio is, the better. The lower the value, the more fully the adhesive structure is destroyed.

[0033] As an example, for the first straight line segment (the bottom long side), mm, (mm / s), at the starting point of the trajectory, the glue in the syringe is allowed to stand for a period of time, and the initial value is taken. Then at the exit After the 155mm long side, the structural parameters have significantly decreased. And for the second straight segment (the short right side), mm), if at the entrance (Given from the value of the first corner exit), then at the exit... The attenuation magnitude of the shorter side is at an existing low level. It was further reduced on the basis, but the reduction was not as significant as that on the longer side.

[0034] In frame 202, the exponential recovery of structural parameters occurs within the corner segment. In this corner segment, the dispensing head speed decreases significantly, the shear rate within the needle decreases accordingly, and the adhesive microstructure begins to recover. Rise back towards 1.0; let the corner passage time be... (Unit: seconds), structural parameters at the entrance are: Then the structural parameters at the outlet for: ; Among them, the time it takes to pass the corner It consists of three parts: a deceleration section, a circular arc section, and an acceleration section. The following formula is used to estimate its strength: ; Simplified to: ; in The starting distance for deceleration (in mm). The velocity of the preceding straight line segment is expressed in mm / s. Minimum speed for passing through a corner (unit: mm / s). The turning radius is in mm. The angle is the rotation angle (in rad); where, in the initial calculation, and Take the base value determined by the corner geometry, i.e., the base deceleration starting distance. and minimum pass speed .

[0035] As an example, take mm, mm / s, mm, rad, the time to pass the first corner is s. Corner entrance Substituting into the recovery formula, we get . The recovery was only from 0.127 to 0.154, a very small recovery. This is because the time to pass through the corner is much shorter than the recovery time constant, and the glue has almost no time to restore the structure within the corner.

[0036] In box 203, the structural parameter values ​​at each corner entrance are obtained through forward recursion. Starting from the trajectory starting point, the changes in structural parameters are calculated alternately for each straight line segment and each corner along the direction of travel to obtain the structural parameter values ​​at each corner entrance on the trajectory. The entire process is a single forward traversal, with very little computation.

[0037] Taking the panel above as an example, starting from the bottom left edge, The forward recursion results are as follows: Exit of the first straight section That is, the value at the first corner entrance; the value at the first corner exit. ; Second straight exit That is, the value at the second corner entrance; the value at the second corner exit. ; Third straight exit That is, the value at the third corner entrance; the value at the third corner exit. ; Section 4 straight exit That is, the value of the 4th corner entrance.

[0038] The data above shows that, firstly, the structural parameters at each corner entrance differ significantly, especially at the first corner entrance. And the third corner entrance It is only 0.012, less than one-tenth of the former; secondly, The overall trend along the path is downward because only a very small amount of structure is restored after each corner, and then it continues to decay after entering the next straight segment. In the current approach, the same deceleration parameters are used for all four corners. A lower corner corresponds to a lower effective viscosity, resulting in a larger glue output and a wider glue line width under the same deceleration parameters.

[0039] In some embodiments, for step S3, in conventional practice, the base deceleration starting distance at each corner is... and minimum pass speed It is determined solely by the corner angle and turning radius. Taking a 90-degree corner with a turning radius of 0.5mm as an example, For example, take 3.0mm, For example, taking 30 mm / s, in this embodiment, a correction term related to the structural parameters is superimposed on the base value.

[0040] in, and The base value is determined by the geometry of the corner (corner angle). and turning radius The specific calibration method is as follows: the glue passes through a sufficiently long straight segment (length...). ) makes After the value has dropped to a steady state, at that steady state The value is the baseline condition, at the target dispensing speed. Below, multiple groups were tested respectively. Combine the width of the adhesive line after the corner, and select the width of the adhesive line in the corner area that is equal to the target width of the straight segment (e.g., Consistent and with minimal deviation The combination as the The base value under the given conditions. For , Typical corners, calibrated Typical value , Typical value For atypical corners (such as...) or Following the same calibration procedure on the baseline Calibrate the corresponding conditions respectively and Generate a lookup table for real-time access.

[0041] Corrected deceleration starting distance for: ; Corrected minimum throughput speed for: ; in The first step obtained from the aforementioned steps The structural parameter values ​​at each corner entrance; To reference structural parameter values, the corner entrance under calibration reference conditions was determined during the calibration experiment. value; The correction increment, in mm, represents the additional deceleration distance required due to thixotropic effects under the reference conditions. This is a correction factor. As a correction factor, reflecting the first The ratio of the degree of damage to the glue structure at each corner entrance to the reference condition, i.e. The lower the value, the larger the correction factor, and the greater the increase in the deceleration starting distance and the increase in the minimum passing speed.

[0042] Among them, the correction increment and correction factor Determined through calibration experiments. and The corner deceleration parameters are corrected from different physical dimensions: This reflects the additional distance required to start deceleration earlier after the effective viscosity of the glue decreases, so that the glue has more time to recover its viscosity before entering the corner. This reflects the need to increase the minimum throughput speed within the corner arc to avoid excessive glue discharge at low speeds due to low viscosity. The main adjustment is when to start decelerating. The main adjustment is to determine the minimum speed for deceleration; in the calibration experiment, first fix the speed... Adjust only Ensure the width of the adhesive line at the corner of the long straight line meets the standard, and then maintain... Unchanged, Adjusted This ensures that the width of the glue line at the corner after the short straight line also meets the standard, thereby decoupling and calibrating the parameters of the two dimensions.

[0043] Specifically, two sets of conditions were selected for dispensing tests: Set 1 involved a long straight section (e.g., 155mm) followed by a 90-degree turn; Set 2 involved a short straight section (e.g., 72mm) followed by a turn at the same angle. Both sets used basic deceleration parameters. The maximum glue line width in the corner area of ​​both sets was measured using a line width detection device (e.g., a CCD line scan camera). The glue line width calculated in step S1 under Set 1 conditions was then used as the reference. The value is taken as For example, if the maximum width of the first group of corners is 0.42mm, the second group is 0.38mm, and the target width is 0.40mm, then for the first group of corners, the initial deceleration distance is gradually increased until the width of the rubber line decreases to 0.40mm. The increased distance is... For example, to obtain 2.0mm; based on this, maintain No change, adjustment This makes the width of the second set of corners reach 0.40mm as well, resulting in... For example, 0.25, this calibration is performed once when changing the glue type.

[0044] As an example, using the parameters of the panel above for calculation, take... mm, , The first corner entrance Correction factor , mm, mm / s; 3rd corner entrance Correction factor , mm, mm / s. The third corner has an additional deceleration advance of approximately 0.26 mm and a minimum speed increase of approximately 1.0 mm / s compared to the first corner. The increased deceleration initiation distance allows the dispensing head to enter the deceleration phase earlier, correspondingly extending the range where the shear rate gradually decreases within the needle tip, and the adhesive viscosity recovers before entering the corner arc; the increased minimum throughput speed shortens the time spent passing through the corner at low speed, reducing the amount of adhesive deposited in that range.

[0045] Specifically, in the capillary channel of the dispensing needle, the relationship between the wall shear rate ̇γ (in s⁻¹) and the average flow velocity ū (in mm / s) within the needle is determined by the flow rate-shear rate relationship in capillary rheology. For a circular cross-section needle, the relationship between the average flow velocity ū and the volumetric flow rate Q (in mm³ / s) is Q = ū·πR², where R is the inner diameter of the needle (in mm), and the wall shear rate ̇γ_w = 4Q / (πR³) = 4ū / R. The movement speed v (in mm / s) of the dispensing head directly determines the relative movement speed between the needle and the substrate. Under constant dispensing pressure, the dispensing flow rate Q is approximately proportional to the movement speed v (to ensure a constant amount of adhesive per unit length). Therefore, the shear rate ̇γ within the needle is approximately proportional to the movement speed v of the dispensing head. Therefore, when the dispensing head begins to decelerate earlier before entering the corner, the decrease in v means that the shear rate γ within the needle decreases synchronously. The shear force on the adhesive weakens, the structural parameter λ begins to recover towards 1.0, and the effective viscosity η subsequently increases. This recovery effect begins before entering the corner arc, making the adhesive viscosity in the corner arc segment higher than the viscosity without prior deceleration, thus suppressing excessive dispensing caused by excessively low viscosity. Optionally, using the modified... and Recalculate the time to pass each corner Substitute the values ​​into the formula from the previous steps to perform an update. Since the time variation for corner passage is very small, a single calculation is usually sufficient to meet the accuracy requirements.

[0046] In some embodiments, the method further includes compensating for the dispensing pressure at the initial transition section of the adhesive trajectory. Specifically, at the starting point of the trajectory, the adhesive, after being left to stand, is in a state of high structural integrity ( The effective viscosity is close to zero shear viscosity. After the dispensing head begins to move, the adhesive is subjected to shear within the needle. It gradually decreases along the path. In the transition range from the initial value to near the steady-state value, the effective viscosity is higher than the steady-state value, resulting in a lower actual dispensing flow rate and narrower glue line width under the same dispensing pressure. Under laminar flow conditions, the dispensing flow rate in the needle channel is directly proportional to the applied pressure and inversely proportional to the glue viscosity. This relationship conforms to the Hagen-Poiseuille law. Therefore, increasing the pressure according to the viscosity ratio can maintain a stable flow rate.

[0047] Initial transition length Pick ,in As a multiple, in this embodiment we take The basis for this value is: when hour, Decay to initial value The viscosity has dropped to below 5% of its initial value, at which point the effective viscosity of the adhesive is close to its steady-state value. and (The deviation is less than 5%), the pressure compensation range has been reduced to within 5% of the benchmark value, and further increasing the compensation length will saturate the improvement of the uniformity of the glue line width. The value can be adjusted within the range of 2 to 5 based on the actual glue line width test results: if the initial glue line width is too narrow (indicating insufficient compensation or premature compensation termination), take the larger value. Value (e.g., 4 or 5); if the initial section of the adhesive line is too wide (indicating over-compensation), take a smaller value. Value (e.g., 2).

[0048] Within the initial transition section, at each position (Unit: mm, measured from the starting point) Dispensing pressure Adjust as follows: ; in The reference dispensing pressure (unit: kPa) corresponds to the pressure value used to obtain the target glue line width when the glue is at a steady-state viscosity. This pressure is obtained by calibration at the end of the straight line segment. The calculation result of the aforementioned attenuation formula in the initial segment is, i.e. ; For steady-state structural parameters, take the calibration values. The end of the straight line segment used at that time Value. For example, if the calibrated straight line length is 200mm, then... . and According to the aforementioned linear relationship calculate.

[0049] Regarding calibration Length of the straight line segment used It should be long enough so that the glue, after passing through the straight segment... It has decayed to a steady-state value, for example The selection criteria are ,at this time Decay to initial value Under these calibration conditions, the end of this straight line segment Value defined as ,Right now: ; For the parameters in this embodiment ( , ),Pick hour: ; Should The value is independent of the forward recursive result of the aforementioned steps and is used alone for the pressure compensation calculation of the initial transition section.

[0050] Taking the calculation of each position as an example: mm (the position where compensation begins after the dispensing head completes acceleration). , mPa·s, mPa·s, ; When mm, , mPa·s, ; mm (end of the first straight line segment) , mPa·s, The compensation magnitude gradually decreases from approximately 2.4 times near the starting point, approaching the baseline value by the end of the first straight segment. (Exceeding...) The pressure after dispensing the adhesive returns to No further compensation will be provided.

[0051] in, The method for determining the glue line width is as follows: Along a sufficiently long straight line (e.g., 200mm), dispense glue at the target dispensing speed, measure the glue line width at the end of the line, and adjust the dispensing pressure until the glue line width reaches the designed target value (e.g., 0.40mm). This pressure is the glue line width. .

[0052] In one embodiment, regarding the calibration of the two time constants, the destruction time constant and the recovery time constant, specifically, the destruction time constant... The viscosity was obtained through a step shear experiment using a rotational rheometer: the adhesive was held at a low shear rate (e.g., 0.01 / s) for 60 seconds to allow the structure to recover, and then switched to a constant shear rate (e.g., 100 / s to 500 / s) similar to the actual shear rate inside the needle. The viscosity decrease over time was continuously recorded, and the result was fitted with an exponential decay function. For example, if the initial viscosity is 95000 mPa·s, the steady-state viscosity is 36000 mPa·s, and the viscosity reading at 0.5 seconds is 57400 mPa·s, then substituting these values ​​into the decay model... achievable s, take s.

[0053] Recovery time constant The viscosity was obtained through a step recovery experiment using a rotational rheometer: After the step shear experiment was completed (the adhesive was in a low viscosity steady state), the shear rate was suddenly reduced to an extremely low value (e.g., 0.01 / s), and the viscosity recovery curve over time was recorded. The result was then fitted with an exponential recovery function. As an example, if the initial recovery viscosity is 36000 mPa·s, the viscosity reading at 3.0 seconds is 57000 mPa·s, and the target recovery value is 95000 mPa·s, then... s; in actual batches For example, take 3.0 to 6.0 seconds. and The viscosity values ​​were read simultaneously in both sets of experiments, corresponding to the initial plateau and steady-state plateau, respectively. The same set of calibration results can be used for the same batch of adhesive within its usage period.

[0054] In some embodiments, for step S4, the corrected deceleration starting distance and minimum passing speed at each corner are spliced ​​with the speed of each straight segment to generate a speed curve for the frame adhesive trajectory. Specifically, the splicing method is as follows: each straight segment runs at a constant speed; before entering each corner, the speed of the straight segment is reduced to the corrected minimum passing speed at that corner according to an S-shaped acceleration / deceleration curve, and the length of the deceleration segment is the corrected deceleration starting distance; after passing through the corner arc, the speed is restored to the speed of the next straight segment according to a symmetrical curve. The pressure compensation curve of the initial transition segment is generated synchronously. The motion controller reads the speed curve according to the interpolation cycle and sends it to each axis servo motor, and the glue dispensing valve controller synchronously reads the pressure curve and adjusts the glue supply pressure. The two maintain timing consistency through a synchronization signal.

[0055] For example, the specific logic for generating the velocity curve includes: Let the first... The planning speed for a straight line segment is (Constant), its rear corner The corrected minimum throughput speed is The corrected deceleration starting distance is From the velocity of the straight segment Reduce to minimum speed at the corner The S-shaped acceleration / deceleration curve is generated as follows: Set the rate of change of acceleration (jerk). (Unit: mm / s³), this value is determined by the servo drive capability of the dispensing equipment, for example... The deceleration phase of the S-shaped velocity curve is divided into three stages: the first stage is characterized by a constant jerk. During this phase, the acceleration decreases linearly from 0 to... The second stage is characterized by constant acceleration. The first stage; the third stage is characterized by constant jerk. During this phase, acceleration from The linear recovery to 0 occurs when the three phases are symmetrical and equal in time, denoted as... It is determined by the following formula: ; Right now: ; Starting from the deceleration start point, according to the interpolation cycle (Unit: s, determined by the motion controller, typical value is...) ) Calculate the velocity value point by point: the first The speed of each interpolation point The velocity-time function of the above S-curve Provided. If according to... The calculated deceleration distance is not equal to the corrected distance. Then To constrain the process, the curve is scaled proportionally while maintaining the shape of the S-curve. This makes the actual deceleration distance equal to The formula for calculating the actual deceleration distance is: ; make The solution is: ; The specific output format of the speed curve is: a sequence of speed commands arranged in chronological order. , ,in , The total motion time for the entire frame's adhesive trajectory, for each speed command. The unit is mm / s. This speed command sequence is sent to the motion controller at interpolation cycle intervals. The motion controller reads the corresponding speed command in each interpolation cycle and converts it into position increment commands for each axis servo motor.

[0056] Optionally, in some embodiments, the above method can be extended to irregularly shaped panels that include non-90-degree corners or continuous turning areas. For non-90-degree corners, and Take values ​​according to the corresponding angle and radius, respectively. The evolution calculation method remains unchanged. For regions with alternating short straight segments and corners, the forward recursion automatically reflects the cumulative effect of shear thinning, with larger corrections at subsequent corners.

[0057] This method introduces structural parameters that continuously evolve along the entire path into the trajectory velocity planning. It quantitatively reflects the thixotropic properties of the frame adhesive, especially the asymmetry of rapid structural failure and slow recovery, into the deceleration parameters at each corner. This ensures that corners after different straight segment lengths can obtain deceleration schemes that match the current adhesive state. Simultaneously, the same set of structural parameters is used to compensate for the adhesive discharge pressure in the initial transition section, making the adhesive line width in the initial section more consistent with that in the steady-state section. As a result, the uniformity of the adhesive line width across the entire circumference of the frame adhesive loop is improved, reducing the risk of adhesive overflow and insufficient sealing in corner areas. During model changeovers, only two time constants need to be measured using a rotational rheometer, and a single calibration experiment needs to be performed to generate a suitable velocity plan.

[0058] Please see Figure 3 , Figure 3 This is a structural block diagram of a dispensing trajectory planning system for OLED module packaging, provided in an embodiment of this application. Figure 3 As shown, the system includes: The trajectory decomposition module 301 is used to decompose the frame adhesive trajectory into several straight line segments and corner segments, and to obtain the length of each straight line segment and the turning angle and turning radius of each corner segment. The structural parameter calculation module 302 is used to calculate the changes in structural parameters alternately for each straight segment and each corner segment along the path travel direction from the trajectory starting point. The structural parameter, representing the integrity of the thixotropic structure of the adhesive, decays exponentially within each straight segment, with the decay rate determined by the adhesive's failure time constant. The structural parameter recovers exponentially within each corner segment, with the recovery rate determined by the adhesive's recovery time constant. The values ​​of the structural parameters at each corner entrance are obtained. The corner parameter correction module 303 is used to correct the deceleration starting distance and minimum passing speed of each corner according to the values ​​of the structural parameters at each corner entrance. The lower the value of the structural parameter, the greater the deceleration starting distance and the higher the minimum passing speed of the corresponding corner. The speed curve generation module 304 is used to splice the deceleration starting distance and minimum passing speed after each corner correction with the speed of each straight segment to generate the speed curve of the frame rubber trajectory.

[0059] Each processing unit and / or module in the embodiments of this application can be implemented by an analog circuit that implements the functions described in the embodiments of this application, or by software that executes the functions described in the embodiments of this application.

[0060] Based on the same inventive concept, this application also provides an electronic device, the method corresponding to which can be the method in the foregoing embodiments, and its problem-solving principle is similar to that method. For example... Figure 4 As shown, Figure 4 This is a schematic block diagram of an electronic device provided in an embodiment of the present disclosure. The device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the methods and / or technical solutions of the foregoing embodiments of the present application.

[0061] In particular, the methods and / or embodiments in this application can be implemented as computer software programs. For example, the embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowchart. When the computer program is executed by a processor, it performs the functions defined in the methods of this application.

[0062] Another embodiment of this application provides a storage medium storing computer program instructions thereon, which can be executed by a processor to implement the methods and / or technical solutions of any one or more embodiments of this application.

[0063] In the above embodiments, the descriptions of each embodiment have different focuses. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. The above descriptions are merely preferred embodiments of this application and explanations of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above technical features, but should also cover other technical solutions formed by arbitrary combinations of the above technical features or their equivalent features without departing from the inventive concept.

Claims

1. A dispensing trajectory planning method for OLED module packaging, characterized in that, include: The frame adhesive trajectory is decomposed into several straight line segments and corner segments, and the length of each straight line segment and the turning angle and turning radius of each corner segment are obtained. Starting from the trajectory's starting point and moving along the path, the changes in structural parameters are calculated alternately for each straight segment and each corner segment to obtain the values ​​of the structural parameters at each corner entrance. The structural parameters characterize the degree of integrity of the adhesive's thixotropic structure, which decays exponentially within each straight segment, with the decay rate determined by the adhesive's failure time constant. The structural parameters recover exponentially within each corner segment, with the recovery rate determined by the adhesive's recovery time constant. Based on the values ​​of the structural parameters at each corner entrance, the deceleration starting distance and minimum passing speed of each corner are corrected. The lower the value of the structural parameter, the greater the deceleration starting distance and the higher the minimum passing speed of the corresponding corner. The correction method for the deceleration starting distance of each corner is as follows: a correction increment is added to the basic deceleration starting distance determined by the corner's turning angle and turning radius. The correction increment is determined based on the deviation of the structural parameter value at the corner entrance from the reference structural parameter value. The correction method for the minimum passing speed of each corner is as follows: the basic minimum passing speed determined by the corner's turning angle and turning radius is multiplied by a correction coefficient related to the deviation. The reference structural parameter value is determined in a calibration experiment. The correction increment and the correction coefficient are calibrated as follows: after a long straight section and after a short straight section, a dispensing test is performed at a corner with the same turning angle and the same turning radius. The glue line width of the two sets of corner areas is measured, and the correction increment and the correction coefficient are calculated based on the difference between the two sets of glue line widths and the target glue line width. By splicing the corrected deceleration starting distance and minimum passing speed at each corner with the speed of each straight segment, a speed curve of the frame rubber trajectory is generated.

2. The method according to claim 1, characterized in that, The values ​​of the structural parameters at the exit of each straight segment are obtained by exponentially decaying the values ​​of the structural parameters at the entrance of the straight segment; the degree of decay of the exponential decay is determined by the length of the straight segment, the planned speed of the straight segment, and the failure time constant; the longer the straight segment or the lower the planned speed of the straight segment, the lower the value of the structural parameters at the exit.

3. The method according to claim 1, characterized in that, The values ​​of the structural parameters at the exit of each corner segment are obtained by exponentially recovering the values ​​of the structural parameters at the entrance of the corner segment; the degree of recovery by exponential recovery is determined by the passage time of the corner segment and the recovery time constant; the recovery time constant is greater than the failure time constant; the passage time of each corner segment is estimated based on the deceleration start distance of the corner segment, the speed of the straight section before entering the corner segment, the minimum passage speed of the corner segment, the turning radius of the corner segment, and the turning angle of the corner segment; when calculating the structural parameters for the first time, the deceleration start distance and the minimum passage speed are taken as basic values ​​determined by the corner geometry.

4. The method according to claim 1, characterized in that, It also includes compensating for the dispensing pressure of the initial transition section of the frame adhesive trajectory; the initial transition section is the path interval from the starting point of the trajectory to the value of the structural parameter decaying to the steady state value; within the initial transition section, the dispensing pressure at each position is adjusted according to the ratio of the effective viscosity corresponding to the structural parameter at each position to the steady-state effective viscosity; the compensated dispensing pressure curve is issued and executed synchronously with the speed curve.

5. The method according to claim 4, characterized in that, The effective viscosity is determined linearly between the zero-shear viscosity and the equilibrium viscosity after sufficient shearing of the adhesive, based on the value of the structural parameter; the zero-shear viscosity and the equilibrium viscosity after sufficient shearing are obtained by rotational rheometer measurement, and the length of the initial transition section is determined by the product of the dispensing speed and the failure time constant.

6. The method according to claim 1, characterized in that, The failure time constant is obtained through a step shear experiment using a rotational rheometer: a constant shear rate is applied to the adhesive from a static state, the viscosity decreases over time, and the failure time constant is obtained by fitting an exponential decay function; the recovery time constant is obtained through a step recovery experiment using a rotational rheometer: the adhesive is reduced from a high shear steady state to a low shear state, the viscosity recovers over time, and the recovery time constant is obtained by fitting an exponential recovery function.

7. A dispensing trajectory planning system for OLED module packaging, characterized in that, include: The trajectory decomposition module is used to decompose the frame adhesive trajectory into several straight line segments and corner segments, and obtain the length of each straight line segment and the turning angle and turning radius of each corner segment. The structural parameter calculation module is used to calculate the changes in structural parameters alternately for each straight segment and each corner segment along the path travel direction from the trajectory starting point. The structural parameters, namely the integrity of the thixotropic structure of the adhesive, decay exponentially within each straight segment, with the decay rate determined by the adhesive's failure time constant. The structural parameters recover exponentially within each corner segment, with the recovery rate determined by the adhesive's recovery time constant. The module obtains the values ​​of the structural parameters at each corner entrance. The corner parameter correction module is used to correct the deceleration starting distance and minimum passing speed of each corner based on the values ​​of the structural parameters at each corner entrance. The lower the value of the structural parameter, the greater the deceleration starting distance and the higher the minimum passing speed of the corresponding corner. The correction method for the deceleration starting distance of each corner is as follows: a correction increment is added to the basic deceleration starting distance determined by the corner's turning angle and turning radius. The correction increment is determined based on the deviation of the structural parameter value at the corner entrance from the reference structural parameter value. The minimum passing speed of each corner is... The speed correction method is as follows: the minimum passing speed determined by the corner angle and turning radius is multiplied by a correction coefficient related to the degree of deviation; the reference structural parameter value is determined in the calibration experiment; wherein, the correction increment and the correction coefficient are calibrated by performing a dispensing test after a corner with the same corner angle and the same turning radius after a long straight segment and a short straight segment respectively, measuring the glue line width of the two corner areas, and calculating the correction increment and the correction coefficient based on the difference between the two glue line widths and the target glue line width; The speed curve generation module is used to stitch together the deceleration starting distance and minimum passing speed after each corner correction with the speed of each straight segment to generate the speed curve of the frame rubber trajectory.

8. A storage medium, characterized in that, When the executable computer program in the storage medium is executed by a processor, it can implement the method as described in any one of claims 1 to 6.

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