Abstract
Integrity tests of HEPA filter are conducted regularly for the air conditioning systems of cleanrooms. For these test, DOP (dioctyl phthalate) is widely used as a tracer particle. But their influences on the human health and sometimes to products themselves are matters of concern. For that reason, we have developed a novel method in which aerosol particles of silica generated by spraying and drying a solution of silica in colloidal form are used as an alternative integrity test method of HEPA filters. This method is safer to human health and no influences to products even in electronic devices. HEPA filter that had artificial pinholes have been subjected to the integrity test and penetrated particle counts have been measured by both the DOP method and the newly developed silica particle counter method. The results obtained by both methods have been well coincided. It has been concluded that the newly developed silica aerosol method can be adopted as a better substitution for the widely used DOP test method.
