General Filter Requirements

Achieving and maintaining ultrapure  water (UPW) is extremely important in light of its widespread presence throughout the manufacture of semiconductor integrated circuits. The technology of the industry has advanced so rapidly over the past few years that it has redefined cleanliness requirements, specifically with regard to the need for quantitatively removing colloidal silica, particles, total organic carbon (TOC), bacteria, pyrogens (bacterial fragments) and metal ions. 

A well-designed UPW system with strategically placed filters, will ensure achievement of this goal, since the type of filter selected in each of the key areas will make a measurable difference in ultimate quality.

To meet the demands of a high-purity deionized (DI) water system, filters must:

· Not contribute organic, particulate or metal ion contamination to the effluent stream
· Not unload trapped contaminants or shed filter material
· Be integrity testable to verify removal ratings
· Perform identically from lot to lot
· Have a low-pressure drop for long life and maximum economy.

DI Water Filter
A well-maintained UPW system will have a number of carefully selected filters and purifiers placed in strategic positions.

A schematic of a DI water system is depicted in the pdf below. The locations of the filters are representative of those found in a typical water system.

Ultrapure Water Introduction