| 摘要: | 石英（Quartz）是一種單晶二氧化矽（SiO2），具有壓電效應並能夠提供穩定的頻率，因此在頻率振盪元件中是不可或缺的材料。隨著科技不斷進步和電子產品需求的日益增長，頻率振盪元件及其所需材料的供應量不斷上升。電子產品的尺寸越來越小，零件需要朝微小化目標前進。為了滿足市場對石英晶圓的需求，減少切割過程中的品質、材料損耗並提升切割速度成為不斷追求的目標。
石英晶圓是一種透明且質地硬脆的材料，傳統的晶粒切割（Dicing）方式主要使用鑽石刀具切割，此法會造成石英晶圓較高比例的損壞，且所需切割道較寬，造成成本增加。因此，非接觸式的雷射加工方式是一種適合於石英晶圓切割的工具。本研究使用波長515 nm、脈寬300 fs的雷射源，對65 μm與80 μm的石英晶圓進行雷射隱形切割研究。在研究中，首先嘗試了三種文獻中提到的雷射切割策略，包括傳統隱形切割、一步驟隱形切割及內部改質搭配表面燒蝕的切割方法。通過分析不同切割策略、比較石英晶圓切割結果的優劣後，提出一道波浪型優化掃描路徑，可在2 mm/s速率下實現表面粗糙度1 μm的切面品質。為使石英晶圓在雷射切割後即可直接實現裂片，本研究採用雷射突發模式（Burst mode）搭配新設計的雷射掃描路徑作為第二道雷射切割方式，形成兩階段的雷射切割策略。首先，以脈衝模式依照波浪型掃描路徑進行石英晶圓內部改質，產生一道弱化的通道；接著再於此通道上，選擇是當地位置以突發模式進行第二道雷射掃描，透過突發模式在材料內部產生裂紋，使石英晶圓沿著預先改質的通道實現晶圓的裂片分離。結果顯示，可以實現不需外力裂片的全雷射石英晶圓切割方式。
;Quartz is a single-crystal silicon dioxide (SiO2) known for its piezoelectric ef-fects and ability to provide stable frequencies, making it essential for frequency os-cillation components. With ongoing technological advancements and the increasing demand for electronic and optoelectronic devices, the need for frequency oscillation components and their materials is constantly rising. As electronic products continue to shrink in size, components must be miniaturized accordingly. To meet the market demand for quartz wafers, reducing quality and material loss during the cutting pro-cess while improving cutting speed are crucial goals.
Single-crystalline quartz is a transparent, hard, and brittle material. Traditional dicing methods primarily use diamond tools, which can cause a higher proportion of damage to quartz wafers and require wider cutting kerfs, increasing costs. Therefore, non-contact laser processing is a suitable method for cutting quartz wafers. This study investigates laser stealth dicing of quartz wafers with thicknesses of 65 μm and 80 μm using a laser source with a wavelength of 515 nm and a pulse width of 300 fs. Initially, three laser cutting strategies from the literature were attempted: conventional stealth dicing, one-step stealth dicing, and internal modification com-bined with surface ablation cutting methods. By analyzing the different cutting strategies and comparing the results, a wavy scanning path was proposed and opti-mized, the result could achieve a surface roughness of less than 1 μm at an optimal dicing speed of 2 mm/s.
Furthermore, to enable immediate wafer separation after laser cutting, this study employed burst mode in conjunction with the newly designed wavy laser scanning path as a second stage of laser processing, resulting in a two-stage laser dicing strategy. First, internal modification of the quartz wafer was performed using pulse mode along the wavy scanning path, creating a relatively weakened channel. Next, burst mode was employed for a second laser scan at selected local positions along this channel, generating cracks within the material that facilitated wafer sepa-ration along the pre-modified channel without needing external force.
The results showed that this fully laser-based quartz wafer dicing method could achieve a surface roughness of less than 1 μm and did not require external force for wafer separation. |
