Micro Embossing of LTCC (Low Temperature Co-fired Ceramic) Green Substrates

Low Temperature Co-fired Ceramic (LTCC) is expected to be widely used as multi-functional substrate for electronic circuit boards and platforms of microsystems. Miniaturised structures such as micro cavities and vias are conventionally formed by mechanical punching or laser machining. These methods, however, encounter difficulties in machining complicated structures, and the minimum dimension is limited by the size of the punching tools or laser beams. This paper reports on micro patterning of LTCC green substrates using micro embossing. The challenges of LTCC embossing include slow material flow during embossing and breakage of embossed substrates during demolding. Hence, the studies on embossing parameters are absolutely important. The process parameters that impact pattern fidelity of LTCC embossing were investigated and optimized in this study. Micro channels with line width as small as 25 mum were formed on LTCC green tapes, and ceramic substrates with embossed micro patterns were obtained after co-firing. The embedded micro channels were obtained as well by laminating the green tapes on the embossed substrates. The results from this work demonstrate that micro embossing is a promising technique for fabricating LTCC-based microstructures.