One of our semiconductor customers-an EU-based OEM specializing in EUV lithography-approached us with a challenge: to manufacture a high-density microchannel cooling plate made from 6061-T6 aluminum. The component required over 1,200 micro-holes, each Ø 0.18 mm, with a depth-to-diameter ratio of 10:1, and positional accuracy under ±5 μm across the entire part surface.
Key challenges included:
Tool breakage due to extreme aspect ratios
Maintaining hole straightness over long drilling depths
Ensuring chip evacuation without deforming the micro-holes
Preventing thermal distortion during continuous drilling
To address these, we employed:
Specialized micro-drill tooling with internal coolant channels
Multi-step peck drilling strategies with dwell and retraction control
Ultrasonic-assisted flushing to ensure chip clearance
In-process thermal stabilization between passes to control expansion
After multiple iterations and simulations, we implemented a 2-pass drilling and reaming process that achieved consistent hole geometry and burr-free inner surfaces. Post-machining inspection using a 500× digital microscope and CMM with probe scanning confirmed:
All holes within ±3 μm tolerance band
Surface roughness below Ra 0.2 μm
Hole-to-hole spacing deviation within ±4 μm across a 150 mm × 150 mm matrix
The component passed helium leak tests, thermal transfer efficiency testing, and was accepted into the customer's pilot build without rework.
