CN-122019939-A - Micro-optical element curing control method for optoelectronic device

CN122019939ACN 122019939 ACN122019939 ACN 122019939ACN-122019939-A

Abstract

The invention belongs to the technical field of ultraviolet light curing, and particularly provides a curing control method of a micro-optical element of an optoelectronic device, which comprises the steps of configuring processing parameters; the method comprises the steps of starting at low power, setting a stress safety threshold, reversely solving to obtain initial starting power meeting safety constraint, starting irradiation at the initial starting power, step-type boosting, maintaining at high power, namely finishing boosting and maintaining irradiation at high power, step-type reducing the power to 0, and ending the process. The method has the key points that the optical power is converted into a dynamic control variable from fixed technological parameters, the predictable and controllable online management of the curing process is realized by establishing a quantitative relation model of power-internal stress, and the process adopts a staged and multi-scale control strategy to ensure the curing to be complete by considering the nonlinear characteristic of the curing dynamics of the material.

Inventors

DUAN JIAN
ZHAO SIYU
WANG CHENGYUN
HUANG YUQIAO
DUAN LIAN
ZHANG FAN

Assignees

中南大学

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (13)

1. The method for controlling the solidification of the micro-optical element of the optoelectronic device is characterized by comprising the following steps: Step one, configuring processing parameters, wherein the processing parameters comprise optical parameters, curing kinetic parameters, thermodynamic and mechanical parameters, geometric parameters and constraint parameters of a glue solution material; Step two, low-power starting is carried out based on processing parameters, and a stress safety threshold is set ; Establishing a mathematical model for quantitatively describing the relation among ultraviolet light power distribution, glue solution solidification degree and internal stress, and positively simulating an application peak value in the whole solidification process based on the data model To apply peak value Infinite approximation but less than application peak As an optimization target, the initial starting power meeting the safety constraint is obtained by inverse solution ; At an initial start-up power Starting irradiation; Step three, step boosting: Calculating that the stress in the material reaches a safety threshold under different curing states Is not less than the irradiation power of (a) And corresponding duration of curing Wherein, the method comprises the steps of, The pulse variable power irradiation times of the step-up stage; based on the irradiation power And corresponding duration of curing Generating a power-time variation table and a power-time variation graph of the step-up stage; Controlling power change according to a power-time change table and a power time change chart of the step-up stage, and implementing curing processing; Step four, maintaining high power, namely finishing boosting and maintaining high power irradiation; step five, step-type depressurization: the power is reduced to 0, and the process is finished.
2. The method of claim 1, wherein the optical parameters of the glue material are defined by absorption coefficients Determining the attenuation law of light intensity along with the irradiation depth; the curing kinetic parameters include a reaction rate constant Power response index Cured self-resistance effect coefficient ; Thermodynamic and mechanical parameters include based on stress relaxation time constants Determined photo-curing reaction rate constant And volume shrinkage Based on the elastic modulus of the cured adhesive Determined stress scaling factor And geometric parameters and constraint parameters determined by process geometry and boundary conditions.
3. The method of claim 2, wherein the geometric and constraint parameters include a thickness of a glue layer Clamping force And an illumination distance.
4. A method of controlling the curing of micro-optic elements of an optoelectronic device according to any one of claims 1-3, characterized by a stress safety threshold The expression of (2) is as follows: ; Wherein, the Expressed as a safety factor in the sense that, Expressed as the contact area of the glue solution with the clamping member, Expressed as clamping force.
5. The method for controlling micro-optical element curing of optoelectronic device according to claim 4, wherein the expression of mathematical model for quantitatively describing the relationship among ultraviolet light power distribution, glue solution curing degree and internal stress is as follows: ; Wherein, the Expressed as transient internal stress at a specific moment And illumination power The stress generated in the lower photo-curing adhesive layer; as a proportion coefficient of the stress, The value rule of (2) is as follows: , wherein, Expressed as the modulus of the glue line, Expressed as volume shrinkage; To cure depth, the glue supplier provides the absorption coefficient of the glue at the target wavelength By passing through Calculating to obtain; And Are all expressed as photocuring reaction rate constants; Expressed as a power response index; expressed as a cure self-resistance effect coefficient, provided by the glue supplier; Expressed as local ultraviolet power density; expressed as the degree of local cure; Expressed as the irradiation time; Expressed as natural constant euler numbers; Represented as a slave surface To the maximum depth Is an infinitely small thickness infinitesimal.
6. The method of claim 5, wherein the initial start-up power is at least one of The expression of (2) is as follows: 。
7. the method for controlling the curing of micro-optical elements of an optoelectronic device according to claim 5 or 6, wherein the irradiation power is obtained And corresponding duration of curing The specific process of (2) is as follows: Non-contact type measuring surface temperature of adhesive layer by using infrared thermometer Monitoring incident light intensity using an ultraviolet light power meter Real-time fluctuations of (a); Establishing a partial differential equation model describing the curing process, and calculating the surface temperature of the adhesive layer according to the model Degree of cure of the adhesive layer ; Comparing the actually measured surface temperature of the adhesive layer with the calculated surface temperature of the adhesive layer, and calculating the solidification degree of the adhesive layer Correcting to restore the local solidification degree of the whole adhesive layer in the thickness direction ; Degree of local solidification Introduction of The model is used for further calculating the irradiation power And corresponding duration of curing 。
8. The method of claim 7, wherein the partial differential equation model describing the curing process is expressed as follows: ; Wherein, the Is the local ultraviolet light power density; is the initial incident optical power density; Is the absorption coefficient of the glue solution under the target wavelength; in order to achieve a cure reaction rate, Is in a cured state; is the density of the material; Is the specific heat capacity of the material; is the thermal conductivity of the material; Is the curvature of the temperature distribution; exothermic for curing, and , Is the total enthalpy of reaction.
9. The method of claim 8, wherein the specific process of controlling the power variation according to the power-time variation table and the power time variation graph of the step-up stage is as follows: When the incident power is Continuous irradiation Second, the stress reaches the preset safety threshold value of the system Immediately stop irradiation, enter A stress relaxation phase of a length of time; By incident power Continuous irradiation After seconds, reenter A stress relaxation phase of a length of time; Repeating the above steps until the incident power is used Continuous irradiation After seconds, reenter And a stress relaxation stage with a time length, and completing the solidification processing of the step-up stage.
10. The method for controlling micro-optical element curing of optoelectronic device according to claim 9, wherein, The setting mode of (2) is as follows: ; Wherein, the As the inverse of the stress relaxation time constant, Is the stress relaxation time constant.
11. The method for controlling the curing of micro-optical elements of optoelectronic devices according to claim 9 or 10, wherein the specific manner of maintaining high power is: At a constant high power The irradiation is carried out for 5-10 seconds, so that the deep layer of material is completely solidified under the condition that the external clamping device provides enough constraint force.
12. The method of claim 11, wherein the constant high power micro-optical element is cured The expression of (2) is as follows: 。
13. the method for controlling the curing of micro-optical elements of optoelectronic devices according to claim 12, wherein the step-wise depressurization is performed in the following manner: Setting down The power value after the secondary is And (2) and ; For the first time per Reduced by 20% Sequentially reducing the pressure; gradually increasing the adjustment amplitude from the second time until the power is zero, wherein the single adjustment amplitude is that each time Reduced by 40% 。

Description

Micro-optical element curing control method for optoelectronic device Technical Field The invention belongs to the technical field of ultraviolet light curing, relates to a curing control method of a micro-optical element of an optoelectronic device, and in particular relates to a low-stress and high-forming ultraviolet light curing method for manufacturing a micro-nano optical element and a precise optical device. Background At present, ultraviolet light curing technology is widely applied to bonding and forming of optoelectronic device packaging, but a main flow process adopts a constant-power continuous ultraviolet light irradiation mode, namely constant-power curing, after ultraviolet light curing glue solution is coated on the surface of a workpiece to be processed, the ultraviolet light source with fixed power is used for continuous irradiation until the glue solution is completely cured. The curing shrinkage of the photo-setting adhesive is a main cause of offset of dispensing, and the alignment coupling precision of the optical device is further affected later, and the main defects are shown in the following points: (1) The existing research does not establish a quantitative relation model between curing condition parameters and stress, and the active regulation and control of light source parameters to inhibit the generation of internal stress and forming defects are difficult to realize, so that the process stability is poor; (2) The light spots are severely distorted, namely, the glue solution flows due to uneven stress generated by thermal expansion, the shape is out of control, the refractive index of the solidified glue layer and the surface flatness deviate from the design value, and the shape of the light spots is distorted; (3) The solidification stress is concentrated, namely constant power continuous irradiation, the difference of solidification rates of the inner surface and the outer surface of the glue solution is obvious, and concentrated stress is generated inside the glue solution, so that the components are shrunk and displaced. The defects seriously restrict the application of the photo-curing technology in the field of high-precision optical manufacturing. Based on this, the fixing is performed with UV glue at this stage. The UV adhesive is mainly prepared from materials such as monomers, oligomers, photoinitiators and the like, and is generally in a liquid state before irradiation. The ultraviolet curing process is essentially a process that a photoinitiator in the UV adhesive absorbs ultraviolet light, bonds absorb energy to break to generate active free radicals to excite monomers or oligomers to perform chemical reactions such as rapid chain polymerization or crosslinking. At this time, the liquid molecules are rapidly converted into solid polymers, the van der Waals distance between the molecules is converted into covalent bond distance, and the volume is significantly contracted. The current main stream solidifying mode adopts constant power or single high-intensity pulse to directly irradiate so that the glue solution surface layer in the illumination area is instantaneously gelled and solidified, and a layer of hard shell is formed. Meanwhile, the penetration depth of ultraviolet light is limited, the surface layer of the glue solution has a shielding effect on light, and the reaction rate and the solidification degree of the internal glue solution are obviously delayed from those of the surface layer. This extremely large cure gradient and "surface-first-second" process can create large uneven stresses, resulting in uneven volume shrinkage and dispensing displacement. At the same time, the cured structure of the outer layer also produces shrinkage deformation with internal non-uniform stresses, and the stresses "locked" inside the material can further develop detrimental residual internal stresses. Disclosure of Invention Based on the defects in the prior art, the invention provides the curing control method for the micro-optical element of the optoelectronic device, which considers the nonlinear characteristic of the curing dynamics of the material, ensures the curing to be complete and can effectively control the micro-displacement of dispensing in the curing process. The invention provides a curing control method of micro-optical elements of an optoelectronic device, which comprises the following steps: Step one, configuring processing parameters, wherein the processing parameters comprise optical parameters, curing kinetic parameters, thermodynamic and mechanical parameters, geometric parameters and constraint parameters of a glue solution material; Step two, low-power starting is carried out based on processing parameters, and a stress safety threshold is set ; Establishing a mathematical model for quantitatively describing the relation among ultraviolet light power distribution, glue solution solidification degree and internal stress, and forward simulating an appl