Where it fits
This service is quantified cleanliness qualification of a filter: send it when incoming inspection needs a number that compares against the manufacturer specification, or when a yield problem needs the filter ruled in or out as a contamination source. It covers organic extractables, metal extractables and particle shedding in one workup — leave any one out and the investigation keeps a blind spot.
Key characteristics
Three axes run in parallel: an isopropanol soak evaluated by GC-MS and non-volatile residue for organic extractables; a hydrochloric acid extraction measured by ICP-MS / ICP-QQQ (detection limit on the order of 1 ppt, covering the common 30 metals plus silicon, boron, sulfur and phosphorus) for trace metals; and particle shedding measured by DMA-CPC.
Results are reported per device rather than as a concentration alone, and the difference matters. At the same parts-per-billion figure, a 20" cartridge releases twice the absolute amount that a 10" one does, so comparing concentrations compares the wrong thing. Per-device numbers line up directly against a manufacturer cleanliness specification or an incoming-inspection limit.
Extraction conditions can be customised to the chemistry actually in use — photoresist, acids and bases, solvents — so results reflect the real process instead of a laboratory default.
Choosing between options
The line between this and its neighbours is cleanliness versus capability:
| Service | Question it answers | Reporting unit |
|---|---|---|
| Filter cleanliness testing (this) | How much does this filter release? | Per device |
| Extractables and leachables testing | What species does this material release into my chemistry? | Identification and quantification by species |
| Cartridge performance testing | What does it retain, and how long does it last? | Retention efficiency, LRV and dirt-holding capacity |
Operation & change-out
What to send: the physical filter, and ideally an unused and a used one as a pair so the comparison means something. Please state cartridge diameter and nominal length (10", for example), which the per-device calculation requires, and the process chemistry in use so custom extraction conditions can be decided. Turnaround is confirmed with the quotation from scope and sample count; samples are held for one month after closure.