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- Closely toleranced pins/bushings – same approach as used for 19-0 tooling
- Requirement: +/-75um module position tolerance in local support coordinate system (per requirements document "ITk Pixel Module Loading Accuracy Requirements" AT2-IP-ES-006-v3)
- Distribute tolerances:
- +/-50um module position relative to loading tooling baseplate coordinate system (to avoid collisions with 100um gap between modules).
- Dowel pins in baseplate – two per module location.
- Bridge to have bushing and slot for precision fit onto dowel pins.
- +/-25um local support position relative to loading tooling baseplate coordinate system (to accurately place modules to meet +/-75um requirement).
- Dowel pin in baseplate – to accurately locate one end of the Stave in Z.
- Tooling to fasten to mounting features on ends of Stave.
- +/-50um module position relative to loading tooling baseplate coordinate system (to avoid collisions with 100um gap between modules).
- Glue with beads to control glue layer thickness
- 100um dia beads, for ~75um glue layer thickness on carbon fiber.
- Loading tooling does NOT control the glue layer thickness.
- Loading bridge to rest on the module's pickup areas (vacuum pad locations) during (~10 minute) hold for gluing.
- Loading bridge to have micrometer adjusters to level the tool relative to the baseplate – to apply pressure at all vacuum pad locations during gluing.
- Loading bridge to have micrometer adjusters to level the tool relative to the pickup table – to make good contact between vacuum pads and module.
- Vacuum pads to pick up modules
- Vacuum pads to fit within clear areas on modules.
- Height adjustment of vacuum pads while on pickup table.
- Vacuum to securely hold modules.
- Tolerances:
- Module position relative to loading tooling baseplate (need +/-.050mm):
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- Stave position relative to loading tooling baseplate (need +/-.025mm):
Tolerance Item | Where Used | Tolerance (mm, Dia.) |
Pin Location | Locating Stave to Baseplate | .025 |
Pick-up Table Edge Accuracy (absolute position) | Locating Module to Pick-up Table *choose loading tooling baseplate coordinate system to line up with 1st module *does not affect gap/distance between modules | .025 |
Total: | .050mm (+/-.025mm) |
- Total for all:
- Limit: +/-.075mm
- Root sum square: +/-.026mm
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