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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 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):
- Baseplate has:
- Dowel pin, stepped, 6mm OD, h7 tolerance. (Misumi SWPG6-P6-Q5.5-L12-B12-E3-F15)
- Dowel pin, stepped, 8mm
- OD, h7 tolerance. (Misumi HWPG6-P8-Q7.5-L11-B12-E3-F15)
- Loading bridge has:
- Bushing, 8mm
- ID, G6 tolerance. (Misumi JBAUN8-20)
- Machined slot, 6mm internal width, G6 tolerance.
- Baseplate has:
- Module position relative to loading tooling baseplate (need +/-.050mm):
| Tolerance Item | Where Used | Tolerance (mm, Dia.) |
Pick-up Table Edge Repeatability (for successive modules) | Locating Module to Pickup Table | .012 |
| Bridge Bushing ID | Locating Loading Bridge to Pick-up Table | .012 |
| Pick-up Table Pin OD | Locating Loading Bridge to Pick-up Table | .012 |
| Pin Location | Locating Loading Bridge to Pick-up Table | .020 |
| Bridge Bushing ID | Locating Loading Bridge to Loading Fixture | .012 |
| Baseplate Pin OD | Locating Loading Bridge to Loading Fixture | .012 |
| Pin Location | Locating Loading Bridge to Loading Fixture | .020 |
Total: | .100mm (+/-.050mm) | |
| Root Sum Square: | .039mm (+/-.019mm) |
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