SOFC interconnect barriers and methods of making same using masks
A novel method to produce thin films spatially disposed on desired areas of workpieces is disclosed. Examples of include the formation of a yttria stabilized zirconia (YSZ) film formed on a desired portion of a stainless steel interconnect for solid oxide fuel cells by Atomic Layer Deposition (ALD). A number of methods to produce the spatially disposed YSZ film structures are described including polymeric and silicone rubber masks. The thin film structures have utility for preventing the reaction of glasses with metals, in particular alkali-earth containing glasses with ferritic stainless steels, allowing high temperature bonding of these materials.
1. A masking apparatus, comprising a mask material which is both flexible and thermally stable in the temperature range of 50-300 degrees Celsius, the mask material being removably attached to a substrate, wherein multiple masks and multiple substrates are removably stacked as a group, in order to prevent atomic layer deposition of a thin film on the substrates on the regions of the substrates covered by the masks.
2. The masking apparatus of claim 1 , wherein the mask material is a polymer.
3. The masking apparatus of claim 1 , wherein the mask material is silicone rubber.
4. The masking apparatus of claim 1 , wherein the mask material is polyimide.
5. The masking apparatus of claim 1 , wherein the mask material is held in place by clamping.
6. The masking apparatus of claim 1 , wherein the clamping is accomplished by applying a differential pressure above and below the mask material.
7. A masking method, comprising choosing a mask material which is both flexible and thermally stable in the temperature range of 50-300 degrees Celsius, shaping the mask material into a shape which can conformally cover and thereby mask out a region of a substrate whereupon it is desirable not to deposit a thin film, removably attaching the shaped mask material to the substrate, removably stacking multiple masks and multiple substrates into a group, placing the stacked group into a deposition chamber, and depositing the thin film by atomic layer deposition, thereby covering at least part of the unmasked substrates with the thin film.
8. The masking method of claim 7 , wherein attaching the shaped mask material to the substrate is accomplished by applying a differential pressure above and below the mask material.
9. The masking method of claim 7 , wherein after depositing the thin film by atomic layer deposition, further removing the shaped mask material and incorporating a portion of the substrate into the structure of a solid oxide fuel cell.
10. The masking method of claim 7 , wherein after depositing the thin film by atomic layer deposition, further removing the shaped mask material and bringing a portion of the substrate which has been covered by the thin film into contact with a vitreous reactive solid.
11. The masking method of claim 7 , wherein attaching the shaped mask material to the substrate is accomplished by applying pressure above the mask material.
12. The masking method of claim 7 , wherein attaching the shaped mask material to each of the substrates in the stacked group is accomplished by stacking alternating masks and substrates to form the stacked group, then applying pressure above and below the stacked group.