Lithography and FFU

In the lithography process, electronic chemicals are prone to produce bubbles when exposed to air. Therefore, in this process, it is necessary to notice the filtration of bubbles other than Granular gels when select the matching filter. Meanwhile, in order to reduce the loss of chemicals, the chemical compatibility of the filter material to the filter object is involved. Lithography process is mainly divided into three steps: coater, exposure, development.

FFU is the pivotal equipment to ensure the cleanliness of workshop, Taking 2.45mx4.95mx2.9m space as an example, the cleanliness grade is 100,000 . To reach 100,000 grade, the FFU supporting HEPA filter should be ordinary HEPA with efficiency over H13. In order to achieve 10,000 clean workshop, the required air volume can be calculated to be equal to 900M3/H; Through conversion, at least one (2*4) FFU is needed to meet the requirements; Air change frequency in clean room reference: Wind changes 50 times in 1,000 grade clean room. Wind changes 25 times in 100,000 grade clean room. Wind changes 15 times in 300,000 grade clean room