A method, apparatus and system for yardstick solidification

Abstract

The application provides a grid scale solidification method, device and system. The method is applied to a grid scale solidification system, the grid scale solidification system comprising a grid scale to be solidified, a clamping body and a base; the method comprises the following steps: obtaining a solidification stress correlation in the solidification connection process of the base and the grid scale; the solidification stress correlation is a corresponding relationship between a pulling force applied to the base along the length direction of the base and the warping degree of the grid scale; determining a target pulling force applied to the base according to the solidification stress correlation; connecting the two ends of the base to the clamping body respectively, and solidifying and connecting the grid scale to the base in the process of continuously applying the target pulling force to the base by the clamping body, and removing the target pulling force and the clamping body after the solidification connection of the base and the grid scale is completed, to obtain a target bonding part. The application can solve the problem that the base warps due to the stress generated in the solidification process in the prior art, so that the bonding assembly quality is affected and the measurement accuracy is low.

Description

Technical Field

[0001] This application relates to the field of adhesive assembly technology, and in particular to a method, apparatus and system for curing a grid ruler. Background Technology

[0002] Grating rulers, such as optical grating rulers and time grating rulers, are high-precision linear displacement sensors. The measuring structure of a grating ruler includes the grating ruler itself and a reading head. The main scale body (also called a glass ruler) is bonded to a substrate and then mounted on a moving part such as a machine tool guide rail. The reading head is mounted on a fixed component. The main scale body and the substrate (also called the base or scale shell) are bonded together with epoxy resin. The curing process of the epoxy resin generates curing stress, causing the epoxy resin to shrink and resulting in warping deformation at both ends of the substrate, thus affecting the measurement accuracy. Summary of the Invention

[0003] The purpose of this application is to provide a grid ruler curing method, apparatus and system to solve the problem of substrate warping caused by stress generated by free shrinkage during the current curing process or residual stress generated by the upper and lower clamping fixtures, which affects the bonding and assembly quality and causes low measurement accuracy.

[0004] To achieve the above objectives, embodiments of this application provide a method for curing a grid ruler. This method is applied to a grid ruler curing system, which includes a grid ruler to be cured, a clamping body, and a substrate. The method includes:

[0005] Obtain the curing stress correlation during the curing connection process between the substrate and the grid ruler; the curing stress correlation is the correspondence between the tensile force applied to the substrate along the length direction of the substrate and the warpage generated by the grid ruler;

[0006] Based on the curing stress correlation, determine the target tensile force to be applied to the substrate;

[0007] The two ends of the substrate are connected to the clamping body respectively. While the target tensile force is continuously applied to the substrate through the clamping body, the grid ruler is cured and connected to the substrate. After the substrate and the grid ruler are cured and connected, the target tensile force is removed and the clamping body is removed to obtain the target adhesive.

[0008] Optionally, based on the curing stress correlation, determining the target tensile force applied to the substrate includes:

[0009] Based on the aforementioned curing stress correlation, determine the first applied tensile force corresponding to the minimum warpage.

[0010] Determine the first tensile force generated during the curing of the adhesive during the bonding process;

[0011] Based on the first applied tension and the first tension, a target tension applied to the substrate is determined.

[0012] Optionally, the method further includes:

[0013] Establish a curing kinetic model for the curing of adhesives during the curing process;

[0014] Based on the curing kinetics model and the time-curing degree equivalent method, the modulus change during the curing process of the adhesive is determined;

[0015] The curing pressure of the adhesive is determined based on the modulus change;

[0016] The preset tensile force applied to the substrate and the adhesive curing pressure are used as the second tensile force applied to the substrate to obtain the degree of warpage of the grid ruler under the second tensile force.

[0017] Based on the second tensile force and the degree of warping, the relationship between the curing stress during the curing connection process between the substrate and the grid ruler is determined.

[0018] Optionally, a curing kinetic model of the adhesive curing during the curing process can be established, including:

[0019] To obtain the heat flow changes during the curing process of adhesives;

[0020] Based on the heat flow change, determine the relationship between heat flow rate and time, or heat flow rate and temperature;

[0021] Based on the relationship between heat flow rate and time, or heat flow rate and temperature, determine the curing kinetic equation of the adhesive;

[0022] Based on the curing kinetic equation, the curing kinetic model is established.

[0023] Optionally, based on the heat flux change, the relationship between heat flux rate and time, or heat flux rate and temperature, is determined, including:

[0024] Differential scanning calorimetry (DSC) experiments were conducted at different curing temperatures to determine the initial relationship between heat flow rate and time; and,

[0025] Obtain isothermal DSC exothermic data;

[0026] The isothermal DSC exothermic data are integrated to obtain the total reaction exothermics at each curing temperature; wherein each total reaction exothermic is associated with the degree of curing of the adhesive.

[0027] Optionally, based on the curing kinetics model and the time-curing degree equivalent method, the modulus change during the adhesive curing process is determined, including:

[0028] Based on the relaxation and creep characteristics of the adhesive, the adhesive is divided into an intrinsic modulus portion and a higher-order viscoelastic effect portion.

[0029] The modulus change during the adhesive curing process is determined based on the intrinsic modulus portion and the viscoelastic effect portion.

[0030] Optionally, the intrinsic modulus portion of the adhesive can be determined using the following formula based on the relaxation creep characteristics of the adhesive;

[0031]

[0032] in, This represents the intrinsic modulus when fully cured at the curing temperature, and is related to the curing temperature used in the curing process. Represents the intrinsic modulus of the uncured material, satisfying ;α c1 and α c2 These represent the degree of curing at the glass transition point and the gel point, respectively; r r The factor representing the two competing factors of stress relaxation and hardening; α mod This represents the ratio of the first difference to the second difference, where the first difference is α and α'. c1 The difference, the second difference is α c2 With α c1 The difference.

[0033] Optionally, the viscoelastic effect portion is determined based on the relaxation and creep characteristics of the adhesive, including:

[0034] Based on the time-curing degree equivalent method, using the same logarithmic coordinate, the viscoelastic properties at different curing degrees are used to obtain the modulus correspondence between each curing degree modulus and the reference curing degree modulus.

[0035] Based on the modulus correspondence, the viscoelastic effect portion is determined.

[0036] Optionally, obtaining the degree of warpage of the grid ruler under the second tensile force includes:

[0037] When the second tensile force is applied to the substrate, the deformation image of the grating is measured according to the three-dimensional digital image correlation method;

[0038] Based on the deformed image, determine the central deformation and the deformation at both ends of the grating ruler;

[0039] The degree of warping of the grid ruler under the second tensile force is obtained based on the central deformation and the deformation at both ends.

[0040] To achieve the above objectives, embodiments of this application also provide a grid ruler curing device, comprising:

[0041] The first acquisition module is used to acquire the curing stress correlation during the curing connection process between the substrate and the grid ruler; the curing stress correlation is the correspondence between the tensile force applied to the substrate along the length direction of the substrate and the warpage generated by the grid ruler;

[0042] The first determining module is used to determine the target tensile force applied to the substrate based on the curing stress correlation.

[0043] The first processing module is used to connect the two ends of the substrate to the clamping body respectively, and to solidify the grid ruler to the substrate while continuously applying the target tensile force to the substrate through the clamping body. After the substrate and the grid ruler are solidified and connected, the target tensile force is removed and the clamping body is removed to obtain the target adhesive.

[0044] To achieve the above objectives, embodiments of this application also provide a grid ruler curing system, comprising:

[0045] The grid ruler to be cured, the clamp body, the base, the nut, the pressure sensor, the first bolt, the first washer, the second washer, and the second bolt;

[0046] The grid ruler is bonded to the substrate with adhesive.

[0047] The clamp is fixed to the workbench of the grid ruler curing system;

[0048] The first bolt passes through the first side plate of the grid ruler curing system and is connected to the nut;

[0049] The first washer is located on the outside of the first side plate and between the first bolt and the nut;

[0050] The pressure sensor is located adjacent to the first bolt;

[0051] The second bolt passes through the second side plate of the grid ruler curing system and connects to the substrate; the second side plate is disposed opposite to the first side plate;

[0052] The second gasket is located outside the second side plate and between the second bolt and the base.

[0053] The beneficial effects of the above technical solution in this application are as follows:

[0054] In this embodiment, the method is applied to a grating curing system, which includes a grating to be cured, a clamping body, and a substrate. The method includes: obtaining the curing stress correlation during the curing connection process between the substrate and the grating; the curing stress correlation is the correspondence between the tensile force applied to the substrate along the length direction of the substrate and the warpage generated by the grating; determining the target tensile force applied to the substrate based on the curing stress correlation; here, the determined target tensile force is the tensile force applied when the grating produces the minimum warpage; connecting both ends of the substrate to the clamping body respectively, and curing the grating to the substrate while continuously applying the target tensile force to the substrate through the clamping body; and after the substrate and the grating are cured and connected, removing the target tensile force and removing the clamping body to obtain the target bonded part. This solves the problem in the prior art where substrate warpage caused by stress generated during the curing process affects the bonding assembly quality and results in low measurement accuracy. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the curing process of the grid ruler and the substrate in the prior art;

[0056] Figure 2 An isometric view of the grid ruler curing system provided in the embodiments of this application;

[0057] Figure 3 A flowchart illustrating the grid ruler curing method provided in this application embodiment;

[0058] Figure 4 This is a front view of the grid ruler curing system provided in the embodiments of this application;

[0059] Figure 5 This is a partial cross-sectional view of the grid ruler curing system provided in an embodiment of this application;

[0060] Figure 6 This is a schematic diagram of a 3D-DIC structure for collecting warpage, provided in an embodiment of this application.

[0061] Figure 7 A fitting curve of tension-warping provided for an embodiment of this application;

[0062] Figure 8 This is a schematic diagram of the structure of the grid ruler curing system provided in the embodiments of this application. Detailed Implementation

[0063] To make the technical problems, technical solutions and advantages of this application clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0064] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0065] In the various embodiments of this application, it should be understood that the sequence number of each process described below does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0066] As shown in the background art, one implementation method can be referred to Figure 1 The main scale body shown is bonded to the substrate (also called the base or scale shell) with epoxy resin. The curing process of the epoxy resin bond generates curing stress, causing the epoxy resin to shrink during curing, which leads to warping deformation at both ends of the substrate, thus affecting the measurement accuracy. To overcome the drawbacks of the prior art, this application provides a scale curing method, apparatus, and system that tightens both ends of the substrate to compensate for warping deformation.

[0067] Furthermore, refer to Figure 3 As shown in the embodiment of this application, a grid ruler curing method is applied to... Figure 2 The illustrated grid ruler curing system includes a grid ruler 1 to be cured, a clamping body 2, and a substrate 3; the method includes:

[0068] Step 31: Obtain the curing stress correlation during the curing connection process between the substrate and the grid ruler; the curing stress correlation is the correspondence between the tensile force applied to the substrate along the length direction of the substrate and the warpage generated by the grid ruler;

[0069] Step 32: Determine the target tensile force applied to the substrate based on the curing stress correlation;

[0070] Step 33: Connect both ends of the substrate to the clamping body respectively, and while continuously applying the target tensile force to the substrate through the clamping body, solidify the connection between the grid ruler and the substrate. After the substrate and the grid ruler are solidified and connected, remove the target tensile force and remove the clamping body to obtain the target adhesive.

[0071] In this embodiment, by obtaining the correlation between the curing stress during the curing connection process of the substrate 3 and the grid ruler 1, it is determined that the grid ruler 1 should be applied with a tensile force along the length direction of the substrate when the minimum warpage is generated, that is, the target tensile force applied to the substrate 3 is determined; during the curing process, the target tensile force is continuously applied to the substrate 3, and the grid ruler 1 and the substrate 3 are cured and connected. After the connection is completed, the target tensile force applied to the substrate 3 is removed. It can be determined that the warpage of the target adhesive is minimized, thereby achieving the tightening of both ends of the substrate to compensate for warpage deformation.

[0072] In a specific embodiment provided in this application, the above method can be used in three steps:

[0073] Step 1: Without attaching the grid ruler 1, obtain the target tension corresponding to the minimum warp degree produced by the grid ruler 1, and tighten the base 3 according to the target tension.

[0074] Step 2: Attach the grid ruler 1 to the base 3, keeping the base 3 taut during this process;

[0075] Step 3: After the adhesive has cured, remove the target tension and take out the bonded part of the grid ruler 1 and the substrate 3 that has been cured. This bonded part is the completed target bonded part.

[0076] Furthermore, refer to Figure 2 and Figure 4 As shown in the illustration, this application also provides a grid ruler curing system, comprising:

[0077] 1. Grid ruler to be cured; 2. Clamp body; 3. Base; 4. Nut; 5. Pressure sensor; 6. First bolt; 7. First washer; 8. Second washer; 9. Second bolt; (Refer to...) Figure 4 As shown, here, base 3 is a single unit;

[0078] The grid ruler 1 is connected to the substrate 3 by adhesive;

[0079] The clamping body 2 is fixed to the workbench surface of the grid ruler curing system;

[0080] The first bolt 6 passes through the first side plate of the grid ruler curing system and is connected to the nut 4;

[0081] The first washer 7 is located on the outside of the first side plate and between the first bolt 6 and the nut 4;

[0082] The pressure sensor 5 is located adjacent to the first bolt 6;

[0083] The second bolt 9 passes through the second side plate of the grid ruler curing system and connects to the base 3; the second side plate is arranged opposite to the first side plate;

[0084] The second gasket 8 is located on the outside of the second side plate and between the second bolt 9 and the base 3.

[0085] In this embodiment, the grid ruler 1 is glued to the base 3; the clamping body 2 is fixed to the workbench; the nut 4 and the first bolt 6 are used together to fasten the base 3 and the clamping body 2. The clamping body 2 should have a raised structure in the middle, with the lengths of the left and right ends of the raised structure being less than the length of the base 3, leaving sufficient vertical space for the nuts on the left and right sides to rotate. A pressure sensor 5 is installed at one end of the grid ruler curing system; since the pressure at the other end is the same, no pressure sensor is needed. In this application, torque is applied using a torque wrench, and the pressure values ​​of the bolts (first bolt 6 and second bolt 9) are dynamically adjusted based on the readings of the pressure sensor 5. The first washer 7 and the second washer 8 prevent loosening when the corresponding bolts are rotated, maintaining the stable operation of the mechanical equipment.

[0086] The method described in this application can be adopted. Figure 2 or Figure 4 The system described above achieves suppression of deformation during the curing of the grid ruler adhesive. Further, step 32 above includes:

[0087] Based on the aforementioned curing stress correlation, determine the first applied tensile force corresponding to the minimum warpage.

[0088] Determine the first tensile force generated during the curing of the adhesive during the bonding process;

[0089] Based on the first applied tension and the first tension, a target tension applied to the substrate is determined.

[0090] It should be noted that the aforementioned grid ruler curing system can be used for simulation to calculate the target tensile force corresponding to the minimum warpage. The direction of the target tensile force in this application can be referenced... Figure 5 The direction of the "tension" is shown; here, the torque wrench applies torque to the first bolt 6 to generate pressure, which in turn generates tension on the base. Further simulation can calculate the target tension corresponding to the minimum warpage.

[0091] In this embodiment of the application, in the curing stress correlation, the first applied tensile force corresponding to the minimum warpage can be determined. The first applied tensile force includes the first tensile force generated by the curing of the adhesive and the tensile force generated by applying torque to the first bolt 6. Since the first tensile force generated by the adhesive is unavoidable, the target tensile force applied to the substrate can be obtained by subtracting the first tensile force from the first applied tensile force. The target tensile force can be controlled by applying torque to the first bolt 6 using a torque wrench.

[0092] The curing stress correlation in this application is data determined in advance through simulation. Therefore, an optional embodiment of this application further includes:

[0093] Establish a curing kinetic model for the curing of adhesives during the curing process;

[0094] Based on the curing kinetics model and the time-curing degree equivalent method, the modulus change during the curing process of the adhesive is determined;

[0095] The curing pressure of the adhesive is determined based on the modulus change;

[0096] The preset tensile force applied to the substrate and the adhesive curing pressure are used as the second tensile force applied to the substrate to obtain the degree of warpage of the grid ruler under the second tensile force.

[0097] Based on the second tensile force and the degree of warping, the relationship between the curing stress during the curing connection process between the substrate and the grid ruler is determined.

[0098] In this embodiment, the pre-simulation calculation can obtain the optimal pressure value, that is, the substrate warpage deformation is minimized under this pressure. The simulation process is as follows: a curing kinetic model of adhesive curing during the curing connection process is established, that is, a curing kinetic model of the adhesive curing process is established, which can represent the relationship between the degree of adhesive curing and the change of time and temperature; and the modulus change during the adhesive curing process is determined by using the time-curing degree equivalence method or principle; based on the modulus change, the adhesive curing pressure is determined, for example, the viscoelastic constitutive model of a custom material can be developed through subroutines. In the simulation process, the bolt pressure determines the final degree of warpage. The bolt pressure value is calculated to obtain the bolt pressure value that minimizes the degree of warpage as the bolt pressure value used in this suppression method. Therefore, the preset tension applied to the substrate and the adhesive curing pressure are used as the second tension applied to the substrate, and the degree of warpage generated by the grid ruler under the second tension is obtained; by changing the second tension, multiple sets of simulation data are determined, and the curing stress correlation during the curing connection process between the substrate and the grid ruler is determined based on the second tension and the degree of warpage in the multiple sets of simulation data.

[0099] Optionally, a curing kinetic model of the adhesive curing during the curing process can be established, including:

[0100] To obtain the heat flow changes during the curing process of adhesives;

[0101] Based on the heat flow change, determine the relationship between heat flow rate and time, or heat flow rate and temperature;

[0102] Based on the relationship between heat flow rate and time, or heat flow rate and temperature, determine the curing kinetic equation of the adhesive;

[0103] Based on the curing kinetic equation, the curing kinetic model is established.

[0104] In this embodiment, the adhesive curing process is a typical exothermic reaction. Differential scanning calorimetry (DSC) can be used to measure the heat flow changes during the adhesive curing process, obtaining the relationship between heat flow rate and time, or heat flow rate and temperature, following the principles: the total area of ​​the exothermic curve is proportional to the total heat released in the curing reaction, and the curing reaction rate is proportional to the heat flow rate, thus establishing the curing kinetic equation for the adhesive. Based on the curing kinetic equation, the curing kinetic model is established.

[0105] For example, this application conducted differential scanning calorimetry (DSC) experiments at different heating rates and isothermal temperatures. The sample mass was approximately 5 mg, the nitrogen flow rate was 50 mL / min, and the heating rates were 5 °C / min, 10 °C / min, 15 °C / min, and 20 °C / min, respectively. The test range was 25 °C to 225 °C. The average value of the exothermic curing reaction at different temperatures was taken, and the total heat of reaction for complete curing of the adhesive was approximately ΔH = 287.35 J / g. DSC experiments were conducted at different curing temperatures to determine the curing kinetic equation of the adhesive.

[0106] Optionally, based on the heat flux change, the relationship between heat flux rate and time, or heat flux rate and temperature, is determined, including:

[0107] Differential scanning calorimetry (DSC) experiments were conducted at different curing temperatures to determine the initial relationship between heat flow rate and time; and,

[0108] Obtain isothermal DSC exothermic data;

[0109] The isothermal DSC exothermic data are integrated to obtain the total reaction exothermics at each curing temperature; wherein each total reaction exothermic is associated with the degree of curing of the adhesive.

[0110] In this embodiment, DSC experiments were conducted at different curing temperatures, set at 65℃, 70℃, 80℃, and 90℃, to obtain the relationship between heat flow rate and time. The obtained isothermal DSC exothermic curves were integrated to obtain the total exothermic reaction at each curing temperature, and thus the final degree of cure at each curing temperature. To more accurately predict the curing reaction process of the adhesive, the relationship between the degree of cure of the adhesive and time and temperature was considered, and a maximum degree of cure α was introduced. max The concept involves establishing the curing kinetic equations for adhesives, typically using kinetic models such as the Kamal-Ryan model to express the isothermal curing process.

[0111] Where α is the degree of curing; m and n are the order of curing reaction, which are preset values; K1 and K2 respectively represent two Arrhenius formulas, which express the formulas for the change of chemical reaction rate constant with temperature.

[0112] The parameters of the adhesive curing kinetic equation were determined based on experimental data, and the calculated data were compared with the experimental data. The established autocatalytic curing kinetic equation showed high consistency with the experimental data and can well reflect the curing process of the adhesive.

[0113] Optionally, based on the curing kinetics model and the time-curing degree equivalent method, the modulus change during the adhesive curing process is determined, including:

[0114] Based on the relaxation and creep characteristics of the adhesive, the adhesive is divided into an intrinsic modulus portion and a higher-order viscoelastic effect portion.

[0115] The modulus change during the adhesive curing process is determined based on the intrinsic modulus portion and the viscoelastic effect portion.

[0116] The adhesive of this application exhibits significant relaxation creep characteristics, and the viscoelastic constitutive model of the adhesive is represented using a generalized Maxwell model. Based on the relaxation creep characteristics, this application divides the adhesive into an intrinsic modulus component and a higher-order viscoelastic effect component, with the adhesive modulus gradually changing with the degree of curing. The modulus change during the curing process is determined based on the intrinsic modulus component and the viscoelastic effect component.

[0117] Optionally, in this embodiment, the relaxation modulus is described by the degree of curing of the adhesive, and the intrinsic modulus is described by the Chile (α) model. Based on the relaxation creep characteristics of the adhesive, the intrinsic modulus of the adhesive is determined using the following formula.

[0118] ;

[0119] in, This represents the intrinsic modulus when fully cured at the curing temperature, and is related to the curing temperature used in the curing process. Represents the intrinsic modulus of the uncured material, satisfying ;α c1 and α c2 These represent the degree of curing at the glass transition point and the gel point, respectively; r r The factor represents the two competing factors of stress relaxation and hardening.

[0120] Where, α mod This represents the ratio of the first difference to the second difference, where the first difference is α and α'. c1 The difference, the second difference is αc2 With α c1 The difference; that is, .

[0121] Optionally, the viscoelastic effect portion is determined based on the relaxation and creep characteristics of the adhesive, including:

[0122] Based on the time-curing degree equivalent method, using the same logarithmic coordinate, the viscoelastic properties at different curing degrees are used to obtain the modulus correspondence between each curing degree modulus and the reference curing degree modulus.

[0123] Based on the modulus correspondence, the viscoelastic effect portion is determined.

[0124] In this embodiment, the higher-order viscoelastic effect adopts the time / degree of cure equivalence principle. Using the same logarithmic coordinate system, the viscoelastic properties at different degrees of cure can be obtained by translation on the time axis. It is assumed that the relaxation times at each stage remain constant throughout the entire curing and post-curing phases, thus obtaining the relationship between the modulus of each degree of cure and the reference modulus of cure, which can be expressed by the following formula: ; where α cure The current degree of cure; α ref For reference degree of cure; α α This is the time-curing equivalence factor.

[0125] Optionally, obtaining the degree of warpage of the grid ruler under the second tensile force includes:

[0126] When the second tensile force is applied to the substrate, the deformation image of the grating is measured according to the three-dimensional digital image correlation method;

[0127] Based on the deformed image, determine the central deformation and the deformation at both ends of the grating ruler;

[0128] The degree of warping of the grid ruler under the second tensile force is obtained based on the central deformation and the deformation at both ends.

[0129] It should be noted that in actual bonding and curing, due to a series of adhesive application operations, the warpage corresponding to the optimal tensile force may not be the minimum. Therefore, testing methods are needed to detect the warpage and identify bonded parts that do not meet the warpage requirements.

[0130] In this embodiment, the warpage deformation identification of the grating ruler can utilize a three-dimensional digital image correlation system (3D-DIC system), which is a three-dimensional deformation measurement tool. The 3D-DIC system is placed perpendicular to the grating ruler, as shown below. Figure 6As shown, when the grid ruler is first bonded, the binocular camera 10 in the 3D-DIC system is used to capture a pair of images during the curing and shrinkage of the adhesive, and calculate the three-dimensional morphology before curing. After curing, another pair of images are captured, and the three-dimensional morphology after curing is calculated. Based on the deformed images, that is, by subtracting the three-dimensional morphology, the warping amount is obtained, thereby obtaining the degree of warping of the grid ruler under the second tension.

[0131] In another specific implementation, this application establishes three analysis steps in finite element simulation. First, the contact between the grid ruler and the substrate is deleted, and a tensile force is applied to the substrate, wherein the direction of the tensile force is as simulated. Figure 5 The direction of the "tension" (since the bolt pressure is the same as its tension on the substrate, the bolt pressure can be simplified to a direct tension applied to the substrate in the finite element simulation). Since the contact between the ruler and the substrate has been deleted, it is equivalent to the ruler not being bonded at this time; Second, keeping the tension constant, activate the contact between the ruler and the substrate, and curing begins; Third, after curing is complete, unload the tension. First, define the warpage: Warpage U = Deformation at both ends U end -Central deformation U center .

[0132] In finite element simulations, changing the tensile force alters the degree of warping at both ends after unloading. By fitting multiple sets of tensile force-warping data obtained from the simulation, a tensile force / warping fitting curve can be obtained, ultimately leading to... Figure 7 The fitted curve shown is such that the lowest point of the curve is the point with the smallest warp. The x-coordinate of this point is the tension force when the warp is minimized, and this tension force is the optimal tension value.

[0133] In summary, this application only requires applying torque to the tension mechanism to generate a certain tension at both ends of the substrate, which can greatly suppress the warping deformation of the substrate caused by the curing shrinkage of the adhesive, which is beneficial to improving the bonding quality and thus improving the measurement accuracy of the scale sensor.

[0134] Reference Figure 8 As shown in the figure, this application embodiment also provides a grid ruler curing device, including:

[0135] The first acquisition module 81 is used to acquire the curing stress correlation during the curing connection process between the substrate and the grid ruler; the curing stress correlation is the correspondence between the tensile force applied to the substrate along the length direction of the substrate and the warpage generated by the grid ruler;

[0136] The first determining module 82 is used to determine the target tensile force applied to the substrate based on the curing stress correlation.

[0137] The first processing module 83 is used to connect the two ends of the substrate to the clamping body respectively, and to solidify the grid ruler to the substrate while continuously applying the target tensile force to the substrate through the clamping body. After the substrate and the grid ruler are solidified and connected, the target tensile force is removed and the clamping body is removed to obtain the target adhesive.

[0138] Optionally, in the grid ruler curing system of this application embodiment, the first determining module 82 mentioned above includes:

[0139] The first determining unit is used to determine the first applied tensile force corresponding to the minimum warpage based on the curing stress correlation.

[0140] The second determining unit is used to determine the first tensile force generated by the curing of the adhesive during the curing connection process;

[0141] The third determining unit is used to determine the target tensile force applied to the substrate based on the first applied tensile force and the first tensile force.

[0142] Optionally, the grid ruler curing system of this application embodiment further includes:

[0143] The first module is used to establish a curing kinetic model for the curing of the adhesive during the curing process.

[0144] The second determining module is used to determine the modulus change during the curing process of the adhesive based on the curing kinetics model and the time-curing degree equivalent method.

[0145] The third determining module is used to determine the curing pressure of the adhesive based on the modulus change;

[0146] The second acquisition module is used to take the preset tensile force applied to the substrate and the adhesive curing pressure as the second tensile force applied to the substrate, and acquire the degree of warpage of the grid ruler under the second tensile force;

[0147] The fourth determining module is used to determine the curing stress correlation between the substrate and the grid ruler during the curing connection process based on the second tensile force and the degree of warping.

[0148] Optionally, the first establishment module described above includes:

[0149] The first acquisition unit is used to acquire the heat flow changes during the adhesive curing process;

[0150] The fourth determining unit is used to determine the relationship between heat flow rate and time, or heat flow rate and temperature, based on the heat flow change.

[0151] The fifth determining unit is used to determine the curing kinetic equation of the adhesive based on the relationship between heat flow rate and time, or heat flow rate and temperature.

[0152] A unit is established to establish the curing kinetic model based on the curing kinetic equation.

[0153] Optionally, the fourth determining unit mentioned above includes:

[0154] The first determining subunit is used to perform differential scanning calorimetry (DSC) experiments at different curing temperatures to determine the first relationship between heat flow rate and time; and

[0155] The first acquisition subunit is used to acquire isothermal DSC exothermic data;

[0156] The first processing subunit is used to integrate the isothermal DSC exothermic data to obtain the total reaction exothermics at each curing temperature; wherein each total reaction exothermic has a corresponding degree of curing of the adhesive.

[0157] Optionally, the second determining module described above includes:

[0158] The first processing unit is used to divide the adhesive into an intrinsic modulus portion and a higher-order viscoelastic effect portion according to the relaxation creep characteristics of the adhesive.

[0159] The second processing unit is used to determine the modulus change during the adhesive curing process based on the intrinsic modulus portion and the viscoelastic effect portion.

[0160] Optionally, the first processing unit described above is specifically used to: determine the intrinsic modulus portion of the adhesive based on the relaxation creep characteristics of the adhesive using the following formula;

[0161]

[0162] in, This represents the intrinsic modulus when fully cured at the curing temperature, and is related to the curing temperature used in the curing process. Represents the intrinsic modulus of the uncured material, satisfying ;α c1 and α c2 These represent the degree of curing at the glass transition point and the gel point, respectively; r r The factor representing the two competing factors of stress relaxation and hardening; α mod This represents the ratio of the first difference to the second difference, where the first difference is α and α'. c1 The difference, the second difference is α c2 With α c1 The difference.

[0163] Optionally, the second processing unit described above is specifically used for:

[0164] Based on the time-curing degree equivalent method, using the same logarithmic coordinate, the viscoelastic properties at different curing degrees are used to obtain the modulus correspondence between each curing degree modulus and the reference curing degree modulus.

[0165] Based on the modulus correspondence, the viscoelastic effect portion is determined.

[0166] Optionally, the second acquisition module described above includes:

[0167] The third processing unit is used to measure the deformation image of the grating ruler according to the three-dimensional digital image correlation method when the second tensile force is applied to the substrate;

[0168] The sixth determining unit is used to determine the central deformation amount and the deformation amount at both ends of the grating ruler based on the deformed image.

[0169] The second acquisition unit is used to acquire the degree of warping of the grid ruler under the second tensile force based on the central deformation amount and the deformation amounts at both ends.

[0170] The above-described implementation embodiments of the grid ruler curing method are all applicable to the embodiments of the grid ruler curing system and can achieve the same technical effect.

[0171] The exemplary embodiments described above are with reference to the accompanying drawings. Many different forms and embodiments are feasible without departing from the spirit and teachings of this application. Therefore, this application should not be construed as limiting the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to make this application complete and convey the scope of this application to those skilled in the art. In these drawings, component dimensions and relative dimensions may be exaggerated for clarity. The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, unless clearly indicated otherwise, the singular forms “a,” “an,” and “the” are intended to include all such forms. It will be further understood that the terms “comprising” and / or “including”, when used in this specification, indicate the presence of the stated features, integers, steps, operations, components, and / or elements, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or groups thereof. Unless otherwise indicated, when stated, a range of values ​​includes the upper and lower limits of the range and any subranges in between.

[0172] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles described in this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for curing a grid ruler, characterized in that, This method is applied to a grid curing system, which includes a grid to be cured, a clamping body, and a substrate; The method includes: Obtaining the curing stress correlation during the curing connection process between the substrate and the grid ruler includes: establishing a curing kinetic model for adhesive curing during the curing connection process; determining the modulus change during adhesive curing based on the curing kinetic model and the time-curing degree equivalence method; determining the adhesive curing pressure based on the modulus change; using a preset tensile force applied to the substrate and the adhesive curing pressure as a second tensile force applied to the substrate, obtaining the degree of warpage of the grid ruler under the second tensile force; determining the curing stress correlation during the curing connection process between the substrate and the grid ruler based on the second tensile force and the degree of warpage; the curing stress correlation is the correspondence between the tensile force applied to the substrate along the length direction of the substrate and the degree of warpage of the grid ruler; Determining the target tensile force applied to the substrate based on the curing stress correlation includes: determining a first applied tensile force corresponding to the minimum warpage based on the curing stress correlation; determining a first tensile force generated by the curing of the adhesive during the curing connection process; and determining the target tensile force applied to the substrate based on the first applied tensile force and the first tensile force. The two ends of the substrate are connected to the clamping body respectively. While the target tensile force is continuously applied to the substrate through the clamping body, the grid ruler is cured and connected to the substrate. After the substrate and the grid ruler are cured and connected, the target tensile force is removed and the clamping body is removed to obtain the target adhesive.

2. The method according to claim 1, characterized in that, Establish a curing kinetic model for the adhesive curing process during the curing bonding process, including: To obtain the heat flow changes during the curing process of adhesives; Based on the heat flow change, determine the relationship between heat flow rate and time, or heat flow rate and temperature; Based on the relationship between heat flow rate and time, or heat flow rate and temperature, determine the curing kinetic equation of the adhesive; Based on the curing kinetic equation, the curing kinetic model is established.

3. The method according to claim 2, characterized in that, Based on the aforementioned heat flux change, determine the relationship between heat flux rate and time, or heat flux rate and temperature, including: Differential scanning calorimetry (DSC) experiments were conducted at different curing temperatures to determine the initial relationship between heat flow rate and time; and, Obtain isothermal DSC exothermic data; The isothermal DSC exothermic data are integrated to obtain the total reaction exothermics at each curing temperature; wherein each total reaction exothermic is associated with the degree of curing of the adhesive.

4. The method according to claim 1, characterized in that, Based on the curing kinetics model and the time-curing degree equivalent method, the modulus change during the adhesive curing process is determined, including: Based on the relaxation and creep characteristics of the adhesive, the adhesive is divided into an intrinsic modulus portion and a higher-order viscoelastic effect portion. The modulus change during the adhesive curing process is determined based on the intrinsic modulus portion and the viscoelastic effect portion.

5. The method according to claim 4, characterized in that, Based on the relaxation creep characteristics of the adhesive, the intrinsic modulus portion of the adhesive is determined using the following formula; ； in, This represents the intrinsic modulus when fully cured at the curing temperature, and is related to the curing temperature used in the curing process. Represents the intrinsic modulus of the uncured material, satisfying ;α c1 and α c2 These represent the degree of curing at the glass transition point and the gel point, respectively; r r The factor representing the two competing factors of stress relaxation and hardening; α mod This represents the ratio of the first difference to the second difference, where the first difference is α and α'. c1 The difference, the second difference is α c2 With α c1 The difference.

6. The method according to claim 4, characterized in that, Based on the relaxation and creep properties of the adhesive, the viscoelastic effect component is determined, including: Based on the time-curing degree equivalent method, using the same logarithmic coordinate, the viscoelastic properties at different curing degrees are used to obtain the modulus correspondence between each curing degree modulus and the reference curing degree modulus. Based on the modulus correspondence, the viscoelastic effect portion is determined.

7. The method according to claim 1, characterized in that, Obtaining the degree of warpage of the grid ruler under the second tensile force includes: When the second tensile force is applied to the substrate, the deformation image of the grating is measured according to the three-dimensional digital image correlation method; Based on the deformed image, determine the central deformation and the deformation at both ends of the grating ruler; The degree of warping of the grid ruler under the second tensile force is obtained based on the central deformation and the deformation at both ends.

8. A grid ruler curing device, characterized in that, include: The first acquisition module is used to acquire the correlation between the curing stress during the curing connection process between the substrate and the grid ruler; The curing stress correlation is the correspondence between the tensile force applied to the substrate along the length direction of the substrate and the warpage generated by the grid ruler; The first determining module is used to determine the target tensile force applied to the substrate based on the curing stress correlation. The first processing module is used to connect the two ends of the substrate to the clamping body respectively, and to solidify the grid ruler to the substrate while continuously applying the target tensile force to the substrate through the clamping body. After the substrate and the grid ruler are solidified and connected, the target tensile force is removed and the clamping body is removed to obtain the target adhesive. The first determining module includes: a first determining unit, configured to determine a first applied tensile force corresponding to the minimum warpage based on the curing stress correlation; a second determining unit, configured to determine the first tensile force generated by the curing of the adhesive during the curing connection process; and a third determining unit, configured to determine a target tensile force applied to the substrate based on the first applied tensile force and the first tensile force. The grid ruler curing device further includes: a first establishing module for establishing a curing kinetic model of adhesive curing during the curing connection process; a second determining module for determining the modulus change during adhesive curing based on the curing kinetic model and the time-curing degree equivalence method; a third determining module for determining the adhesive curing pressure based on the modulus change; a second acquiring module for acquiring the degree of warping of the grid ruler under the second tension by using a preset tensile force applied to the substrate and the adhesive curing pressure as a second tensile force applied to the substrate; and a fourth determining module for determining the curing stress correlation between the substrate and the grid ruler during the curing connection process based on the second tensile force and the degree of warping.

9. A grid ruler curing system, characterized in that, include: The grid ruler to be cured, the clamp body, the base, the nut, the pressure sensor, the first bolt, the first washer, the second washer, and the second bolt; The grid ruler is connected to the substrate by an adhesive; The clamp is fixed to the workbench of the grid ruler curing system; The first bolt passes through the first side plate of the grid ruler curing system and is connected to the nut; The first washer is located on the outside of the first side plate and between the first bolt and the nut; The pressure sensor is located adjacent to the first bolt; The second bolt passes through the second side plate of the grid ruler curing system and connects to the substrate; the second side plate is disposed opposite to the first side plate; The second gasket is located on the outside of the second side plate and between the second bolt and the base; The process includes: establishing a curing kinetic model for adhesive curing during the curing connection process; determining the modulus change during adhesive curing based on the curing kinetic model and the time-curing degree equivalence method; determining the adhesive curing pressure based on the modulus change; using a preset tensile force applied to the substrate and the adhesive curing pressure as a second tensile force applied to the substrate, and obtaining the degree of warpage of the grid ruler under the second tensile force; determining the curing stress correlation between the substrate and the grid ruler during the curing connection process based on the second tensile force and the degree of warpage; the curing stress correlation is determined by applying a preset tensile force along the length direction of the substrate to the substrate. The correspondence between the tensile force and the warpage generated by the grid ruler; the first applied tensile force corresponding to the minimum warpage is determined according to the curing stress correlation; the first tensile force generated by the adhesive curing during the curing connection process is determined; the target tensile force applied to the substrate is determined according to the first applied tensile force and the first tensile force; the two ends of the substrate are respectively connected to the clamping body, and the grid ruler is cured and connected to the substrate while the target tensile force is continuously applied to the substrate through the clamping body; after the substrate and the grid ruler are cured and connected, the target tensile force is removed and the clamping body is removed to obtain the target adhesive.

Images