Fugitive Carbon Paste
Summary
C12 Fugitive Carbon Pastes are optimized for creating embedded cavities, microchannels, and MEM's structures in Low Temperature Co-fired Ceramic (LTCC) multilayer devices and other laminated components. C12 Fugitive Carbon Pastes are also very effective for creating meso-scale features in High Temperature Co-fired Ceramics (HTCC) and other ceramic composites.
Description
C12 thermally Fugitive Carbon Pastes are sold as pastes that can be screen printed or dispensed from a syringe. C12 Fugitive Carbon Pastes are made with specially processed, ultrapure carbon that leaves no residue after debinding and sintering. C12 Fugitive Carbon Paste can be used to form embedded channels, cavities, and MEMs structures in LTCC and HTCC multilayer substrates. C12 Fugitive Carbon Paste can be printed or dispensed before the multilayer lamination process. C12 Fugitive Carbon Paste inserts provide support, and create an open unfilled space after the debinding and sintering process. C12 Fugitive Carbon Pastes have the highest solids loading available, which results in very low sagging and crack-free multilayer ceramic structures. Other thermally fugitive pastes and materials with lower carbon loading and excessive binder content often cause stress, warping, and damage to delicate structures during firing. C12 Fugitive Carbon Pastes can be a cost-effective alternative to using removable inserts such as platinum or latex to create structural features. C12 Fugitive Carbon Pastes are designed to be compatible with all major commercial LTCC tape and screen printable systems.
Ultrapure C12 Fugitive Carbon Pastes are engineered to burn out cleanly in air atmospheres. C12 Fugitive Carbon Pastes begin to rapidly oxidize at 600C, just before pore closure in the LTCC glass ceramic matrix, leaving behind well-defined features such as cavities and channels. C12 Fugitive Carbon Pastes create precise, stress-free structures, unlike conventional fugitive materials such as waxes and polymers, which often leave residue and result in stress related deformation.
Advantages of C12 Fugitive Carbon Paste
♦ Forms in-situ, buried channels, cavities, and MEMs structures in LTCC and other multilayer substrates.
♦ Prevents deformation during high pressure lamination of multilayer structures.
♦ Prevents slumping and cracking during firing.
♦ Contains high purity carbon which burns out cleanly in air atmospheres - gas phase directly sublimates without causing stress on green parts.
♦ Cost effective substitute for removable inserts (e.g. latex, platinum, etc.)
♦ Does not require complex lamination and firing cycles that are necessary when using other fugitive materials such as wax or polymeric materials.
♦ Compatible with all major commercial LTCC tape and screen printable systems.
C12 Fugitive Carbon Pastes begin rapid burn-out (oxidation) in air just before pore closure begins in LTCC ceramic (DP951 Green Tape).
(a) Front of mesovalve manifold with standard connectors. (b) Back of manifold showing contoured channels formed by LTCC Carbon Paste lamination as described by K. Peterson, et al., in Ref. 2. (Photo reproduced with permission of International Microelectronics And Packaging Society, Washington DC, CICMT 2005).
Concept design for a “thermally isolated” micro-hotplate in a ceramic (LTCC) substrate. Suspended bridge structure is printed on top of cavity filled with thermally fugitive C12 Fugitive Carbon Paste.
Recommended firing schedule for creating defect-free microchannels and buried cavities in LTCC multilayers.
Air core inductors fabricated using LTCC Carbon Paste with LTCC tape and screen printed conductors as described by K. Peterson, et al., in Ref. 2. (Photo reproduced with permission of International Microelectronics And Packaging Society, Washington DC, CICMT 2005).