Clean‑room production for semiconductors and precision optics sets strict limits on particle generation, outgassing and structural stability. Vertical granite bases, widely used for mounting cameras, sensors and motion axes, differ significantly from ordinary workshop‑grade components. Improper selection will introduce contamination or trigger precision loss even if geometric accuracy meets specifications. UNPARALLELED sorts out practical selection principles tailored for clean‑room scenarios.
First priority goes to surface treatment that suppresses particle shedding. In clean‑room settings, fine grit flaking from substrate surfaces directly threatens product yield. Ordinary ground granite may retain loose mineral grains. For vertical bases deployed in clean workshops, the working and side surfaces need complete closed‑texture nano‑lapping. Open pores on stone surfaces must be minimised. Porous, coarse‑grained blanks should be rejected, as loose particles may fall off under long‑term equipment vibration and pollute surrounding working space. Surface sealing treatment can be adopted where required to further lower particle‑release risk.
Material stability under clean‑room cyclic conditions cannot be ignored. Many assume constant temperature inside clean‑rooms means zero deformation risk. In fact, local heat from sensors and moving modules creates partial temperature gradients on vertical supports. Selected granite shall have consistent low thermal expansion performance. Raw material batches need uniform mineral composition. Avoid mixed‑origin stone, which may produce uneven local distortion when heated partially. Sufficient stress‑relief ageing of blanks is essential. Residual stress inside the base may slowly release over time and cause verticality drift, affecting optical sensor alignment. 
Embedded fastener quality is a hidden clean‑room risk point. Vertical bases carry stacked assemblies, so mounting holes bear frequent bolt pre‑tension. Direct tapping on granite is forbidden for clean‑room versions. Poorly installed inserts may loosen, generating tiny abrasive debris under vibration. Interference press‑fitted stainless‑steel inserts are preferred over adhesive‑bonded ones. Each insert needs pull‑out strength verification. Glue overflow during installation must be fully removed. Residual adhesive will outgas in sealed clean‑room space and contaminate optical elements and wafers.
Structural form shall balance rigidity, weight and airflow characteristics. Solid thick‑wall structures bring high rigidity yet increase overall weight and obstruct internal airflow. Heavy solid blocks are not always the best choice for clean‑room vertical bases. Under the premise of guaranteed rigidity, properly optimised hollow‑out and notch structures can reduce dead weight and improve laminar‑airflow passing‑through performance. Sharp outer corners should be avoided; rounded transitions reduce dust accumulation dead‑zones. Too many complex grooves will trap fine dust and bring extra cleaning burden for daily maintenance.
Dimensional tolerance focus shifts for vertical‑orientation indicators. Unlike horizontal platforms emphasising flatness, vertical bases attach more importance to long‑range perpendicularity, parallelism between multi‑group mounting planes and hole‑position accuracy. After finishing, full‑set geometric inspection shall be completed under simulated vertical clamping state, not merely measured lying flat. Some workpieces show qualified indexes in horizontal placement yet produce deflection once erected. Simulation inspection helps avoid such on‑site mismatches.
Special requirements for delivery and on‑site handover also belong to clean‑room selection rules. Ordinary industrial‑grade packaging will bring external dust pollution. Components for clean‑room use need particle‑free packaging procedures: dust‑removal cleaning before packing, anti‑dust film wrapping and dedicated inner protective materials. On‑site acceptance should include surface particle check besides geometric report confirmation.
To sum up, selecting granite vertical bases for clean‑rooms is more than checking flatness and perpendicularity. Anti‑shedding surface finishing, low‑outgassing embedded structures, airflow‑friendly structural design and vertical‑state inspection all count. Properly selected vertical granite bases keep structural precision while avoiding contamination risks, matching the strict operating requirements of semiconductor and optical clean‑room production lines.