Motivation for this project is that outside industruial semiconductor production the processed wafer quantities are small. In academia it is common to process 1-3 wafers at a time. Therefore wet etching and other dipping is often done in a beaker. It is quite difficult to find small dippers for 2 inch wafers that fit into a standard 250 ml beaker.
This 2 inch wafer dipper is designed to fit into a 250 ml Schott Duran beaker. Number of wafers that can be fitted are automatically calculated and taken into account. The user needs to think only the size of his or her beaker and ofcourse the wafer dimensions.
The design can be found here: Parametric wafer dipper
Designer
Aalto University, Department of Electronics and Nanoengineering
Design
The design can be found here: Parametric wafer dipper
The code is parametric and the comments should be enought to edit the design as one wishes.
I recommend printing the dipper upright. The Lulzbot TAZ6 printed this one nicely.
CAD images
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Dipper for 2 inch wafers with circular cut.
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Dipper for 2 inch wafers with rectangular cut.
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Dipper for 4 inch wafers, showing the parametric design.
Notes on the design
Check chemical compatibility of your used materials before printing! No materials recommendations are given on purpose. Check the printing material, the used fluids and the samples to be inserted so that no unwanted reactions occur.
- The wafers only touch the dipper at the edges, where the edge exclusion anyway limits the usefulness of the edge part.
- The bottom has a nice drain for the fluid to drain out. This feature is often overlooked in commercial dippers.
- The wafers are nicely fixed in the dipper, from the sides and the bottom. Accidental dropping of the wafers from the dipper is almost impossible.
Savings per print
Now this is a difficult number to give as I have not found similar dippers. A Korean supplier says the price is roughly ~260€ for a 2" Teflon dipper. As the design presented in this wiki is customized, at least same price can be used for savings calculations, assuming the used material isa similar to Teflon.
With 100% fill 3.8 m of 2.85 mm filament is required. The chosen material affects the savings, but assuming a very bad case where the print requires one whole spool of 1.75mm FEP filament which cost ~100€, the savings are at least ~160€/print.