Test Method for Liquid Filter Performance

Test Method for Liquid Filter Performance

By SEMI Japan

The Liquid Filter Task Force under the Liquid Chemicals Japan TC Chapter recently submitted the draft document 5421: New Standard: Test Method for Particle Removal Performance of Liquid Filter Rated Below 30 nm with ICP-MS in ballot cycle 6, 2013.

Although filters for liquid chemical related below 30nm have been widely used in our industry, there currently is no standardized test method for addressing such filters.

In order to develop such test method, this activity was proposed by Toshiba and submitted SNARF was approved in the spring of 2012.

Document 5421 is an extension of SEMI C82-0713 "Test Method for Particle Removal Performance of Liquid Filter Rated 20 to 50 nm With Liquid-Borne Particle Counter", which describes the test method for particle removal performance of liquid filter rated 20-50 nm with optical particle counter. The test particle as tracer material is gold nanoparticle (GNP) certified as National Institute of Science and Technology (NIST) -Reference Material, as similarly used in SEMI C82. 

*More information about C82 is available on the following site.


Document 5421 defines a test method for below 30 nm-rated filters mainly used for chemical filtration by using GNP and ICP-MS as particle concentration detector. 

A purpose of this document is to provide a standard of mono-dispersed gold nanoparticle (GNP) challenge test for liquid filter rated below 30 nm using ICP-MS.  Two appendixes are included and are the subject of voting. Appendix 1 outlines definitions with respect to ligand addition and the Appendix 2 describes the particle size of NIST reference materials. The following areas are to be addressed in this document:

  • The test condition such as fluid, flow rate, pressure, GNP concentration, ligand concentration, membrane treatment etc.
  • The type of filter evaluated.
  • The type of gold nanoparticle (GNP)
  • The method of membrane treatment prior to the test for decreasing the adsorbing effect.
  • The description of the test result.

Ballot 5421 was recently adjudicated during the Liquid Chemical Committee’s Japan chapter, and failed committee review. The authors will now revise the document based on voter input, and reballot in a future cycle. Please contact SEMI Japan staff if you have any questions about this document. Chie Yanagisawa (cyanagisawa@semi.org)

SEMI Standards Watch, October 2013