Table 1.
Overview of the glass (micro)machining fabrication techniques and their general capabilities.
| Methods | Minimum Fabricated Hole Size (μm) | Aspect Ratio | Drilling Rate (μm/min) | Cutting Tool Needed | Risk of Defects or Cracks Being Generated | Pre-process Quired | Ref. |
|---|---|---|---|---|---|---|---|
| Focused electrical discharging method | >20 | Approx. 10 | 24,000,000 | No | No | No | [39] |
| Wet etching | 1 | Approx. 0.7 | 15 | No | Yes | Yes | [30] |
| Dry etching | 0.5 | <10 | Approx. 1.2 | No | Yes | Yes | [31] |
| Deep NLD etching a | >1 | >8 | 0.75 | No | Yes | Yes | [32] |
| Powder blasting | >20 | <3 | 0.4 | Yes | Yes | Yes | [33,34] |
| Mechanical drilling | >100 | >40 | 1520 | Yes | Yes | Yes | [38] |
| Laser drilling | >100 | >5 | 120,000 | No | Yes | No | [35] |
| Electrochemical discharge method | >50 | >7 | 100–4000 | Yes | No | No | [36,37] |
a Deep NDL etching: Deep neutral loop discharge plasma etching.