ABSTRACT

Optical components are often adjusted to maintain their alignment along the optical axis. They are fixed at their optimal positions particularly using ultraviolet (UV) ray-curable adhesives. To achieve a micron-level positional accuracy, it is necessary to understand adhesive shrinkage while curing and the resulting deformation of the adhesive joint. However, it is challenging to perform a quantitative evaluation of the cure shrinkage and mechanical properties of adhesives given the process complexity and strong dependence on curing conditions. Therefore, this study clarified the effects of various curing conditions on the curing extent of an adhesive under UV curing for positioning and heat curing as a post-curing process. The cure shrinkage, coefficient of thermal expansion, and viscoelastic properties of the adhesive were also measured. Each material property could be defined as a function of the curing extent to predict the changes in the properties under different curing conditions. The adhesive curing process was divided into three stages: adhesive gelation under UV irradiation, fast reaction stage under heating, and slow reaction stage under heating. The adhesive state changed from viscous to viscoelastic to elastic as it cured, and this process proceeded in the aforementioned three stages. Three different formulae were fitted corresponding to each stage, with good agreement with the experimental measurements.

摘要

经常调整光学元件以保持它们沿光轴对齐。它们被固定在最佳位置，特别是使用紫外线 (UV) 射线固化粘合剂。为了达到微米级的定位精度，有必要了解固化时的粘合剂收缩以及由此产生的粘合剂接头变形。然而，鉴于工艺复杂性和对固化条件的强烈依赖性，对粘合剂的固化收缩和机械性能进行定量评估具有挑战性。因此，本研究阐明了各种固化条件对粘合剂在紫外固化定位和热固化作为后固化工艺下固化程度的影响。还测量了粘合剂的固化收缩率、热膨胀系数和粘弹性能。每个材料特性都可以定义为固化程度的函数，以预测不同固化条件下特性的变化。胶粘剂固化过程分为三个阶段：紫外线照射下胶粘剂凝胶化、加热下快速反应阶段和加热下慢反应阶段。在固化过程中，粘合状态从粘性变为粘弹性再到弹性，这个过程在上述三个阶段中进行。对应于每个阶段拟合了三个不同的公式，与实验测量具有良好的一致性。加热下的快速反应阶段和加热下的慢反应阶段。在固化过程中，粘合状态从粘性变为粘弹性再到弹性，这个过程在上述三个阶段中进行。对应于每个阶段拟合了三个不同的公式，与实验测量具有良好的一致性。加热下的快速反应阶段和加热下的慢反应阶段。在固化过程中，粘合状态从粘性变为粘弹性再到弹性，这个过程在上述三个阶段中进行。对应于每个阶段拟合了三个不同的公式，与实验测量具有良好的一致性。