Fabrication of porous material for micro component application by direct X-ray lithography and sintering
Fabrication of porous material in complex shape, in the range of several hundred microns size and high aspect ratio material is introduced. The process utilizes and combines the X-ray lithography technology and SU-8 photoresist that has great advantage in shaping high aspect ratio micro part; and powder metallurgy with sintering process that allow formation of neck that gives strength to the material and in the same time shape to desired form. The process started by mixing the steel micropowder, surfactant and SU-8 photoresist with the composition 50%, 5% and 45%, respectively. The process followed by soft baking and exposure under X-ray light. After the exposure process and standard Lithography processes were done, the challenge comes from the pores fabrication. It is started by removing the SU-8 photoresist by thermal process regarded to the Thermogravimetric Analysis (TGA) diagram. The processes are then finalized by sintering process where the initial stage of sintering are kept forming many pores instead of dense material. It is found that the non penetrating pores mostly happened compared to interconnected pores. This novel process brought to the alternative to fabricate porous material with complex shape, high aspect ratio and in several hundred micron size that might be useful for supporting system in the micro/small devices.
porous material x-ray lithography sintering micro part fabrication