>> The Development and Applications of AMC Analysis Software
To predict the cleanroom AMC ( Airborne Molecular Contamination ) concentration is an important point in the AMC control of applications of chemical filter.
Especially after installing the chemical filters, the upstream concentration will be smaller than that expected so that we should consider the influence of chemical filters if a reasonable definition of upstream concentration and acceptance criteria would like to be defined.
In this e-News, we will introduce our self-developed AMC software by C++ for your further reference.
>> Preface
Preface
To develop this software stemmed from the treatment of AMC problem of photo area and maskroom (storage for reticles) at the same time.
In order for smooth operation, it is a popular way to locate maskroom in the photo area. Some companies use the common FFU recirculation design for maskroom and photo area but it is also possible to let maskroom independent from photo area. Whatever design is selected, it is mandatory for us to evaluate the interactions between these two cleanroom at the same time.
And this is the reason why we developed this software for this application.
The concept we used is mass conservation law and control volume. The governing equations will be derived first, and transferred those into matrix form, and finally we try to solve the matrix and get the results.
>> Analysis Model
Analysis Model
Please refer to the figure below, we have a cleanroom with an independent isolated room and they use a common return air shaft.
>> Mass Conservation and Control Volume Approach
Mass Conservation and Control Volume Approach
As the segmentation of the above figure by control volume concept, we can derive the equations as follows,
The matrix [A],[B], and [X] could be written as follows,
>> Applications
Applications
1. Based on different HVAC system design concept, we can have following different kinds of system for maskroom,
2. Because it is two-room based software, you can regard one room as a tool or another area of cleanroom.
3. It is also available for the calculations of different cleanroom FFU coverage.
>> Conclusions
Conclusions
We successfully developed an AMC software and also applied to our engineering projects and also we have experience to make calculation comparison with other chemical filter vendors.
It is believed we could achieve a better AMC service for our customers.