Silson membranes are most often supplied as individual membranes but they can also be supplied as intact wafers and these are preferred where wafer-scale processing, such as coating with metals or preparing the substrates for cell culture, will take place prior to the individual frames being separated from the wafer.
There are some applications where it is difficult to process individual frames but the application does not require a full wafer of windows processed under the same conditions and it is for these circumstances that Silson developed the multi-frame array or MFA as an intermediate product.
The most popular MFA is 23.5 mm x 23.5 mm and this outer frame contains a 4 x 4 array of 5.0 mm x 5.0 mm frames with the membrane of the appropriate size and thickness in the centre of each frame. This allows 16 membranes to be processed and samples prepared under identical conditions and then separated into the individual frames.
These MFAs are available for most standard membrane size and thickness combinations, a frame thickness of 200 µm being preferred for ease of customer separation of the individual frames from the MFA.
TEM windows or grids are very popular in MFA formats, the standard 23.5 mm MFA1 containing a 7 x 7 array of individual frames. As this is still a relatively large number of frames per MFA there is also the option for two smaller MFAs containing TEM frames. The 17.5 mm x 17.5 mm MFA2 contains a 5 x 5 array of windows and the 14.0 mm x 14.0 mm MFA3 contains a 4 x 4 array of TEM frames.
See our videos on YouTube on how to chip out MFAs: