The most popular designs of Silson silicon nitride membranes consist of a single square membrane in a larger square frame with the membrane centrally located within that frame.
The maximum membrane size available varies as a function of both membrane size and thickness, whether used with no applied pressure or as a vacuum window.
If a larger window is required than is possible for a given membrane size and thickness then it is possible to form arrays of membranes to produce multi-element windows.
In some cases multi-element windows are also used to compartmentalise samples, with each etch pit behind the separate membranes used to hold different samples.
A very popular design of multi-element window consists of a 3 x 3 array of 3.0 mm x 3.0 mm membranes with a 0.5 mm support rib between each adjacent membrane. The overall window size is then 10.0 mm x 10.0 mm with an open area transmission of greater than 80%. This window is usually supplied in a 14.0 mm or 17.5 mm frame and can be further mounted into a metal holder for increased support and ease of handling.
A large proportion of multi-element windows are supplied to meet individual customer’s specific designs.