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English: Aluminum Nitride Carrier Tooling for Isolation Pockets and Fragile Ribs
The AlN carrier case is about choosing diamond tools for a ceramic drawing that has isolation pockets and ribs too thin for metal-cutting assumptions. Search intent here is practical: prevent edge chips while preserving pad height.
Ceramic carrier drawing read before diamond grinding
| Ceramic feature | Diamond tool choice | Reason on the drawing |
|---|---|---|
| Isolation pockets | 8 mm fine-grit diamond router, low runout spindle | Carbide abrasion would generate chips and subsurface damage. |
| Fragile ribs | 4 mm resin-bond diamond wheel with shallow passes | Keeps force below rib bending limit. |
| Screw islands | Diamond cup wheel, light finish skim | Preserves pad height without hand lapping. |
| Clearance holes | Ultrasonic diamond core drill with wax backing | Reduces exit breakout. |
| Edge chamfers | Small diamond chamfer pin | Creates controlled edge break without loose grit scratching. |
Low-force grinding sequence
Grind the larger isolation pockets first with a wax-backed support, then finish screw islands before clearance holes. Ribs are touched only after surrounding material is relieved so grinding force does not bend or crack them.
Crack, dust and edge-chip control
Aluminum nitride dust is abrasive and electrically relevant. Dust extraction, clean coolant and low runout are treated as tooling controls. A tool is retired when pocket edges become frosted or the rib corner shows a bright chip.
Flatness and isolation inspection
Flatness is mapped across screw islands, rib edges are reviewed optically, clearance holes are pin-checked and isolation pocket depth is compared to the drawing stack. A part is rejected for functional edge chips even if overall size is correct.
Ceramic tooling FAQ
Why use diamond tools on AlN?
AlN is abrasive and brittle; diamond grinding controls edge chips better than carbide milling.
When are screw islands finished?
Before hole breakout, while the carrier still has broad support.
What defect is most serious?
A functional chip at an isolation rib or screw island edge.
