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MULTILAYER CERAMIC STRUCTURAL ELEMENT for CATALYST CONTAINMENT, GAS DISTRIBUTION, or CHANNEL FORMATION

IP.com Disclosure Number: IPCOM000004584D
Original Publication Date: 2001-Feb-23
Included in the Prior Art Database: 2001-Feb-23
Document File: 2 page(s) / 1M

Publishing Venue

Motorola

Related People

Stephen P. Rogers: AUTHOR [+3]

Abstract

Multilayer ceramic technology provides a method for the manufacture of 3D monolithic structures that are thermally and chemically robust integrated systems with embedded electrical components and fluid flow channels and cavities. Thin sheets or tapes (0.007" 0.010" thick) containing ceramic particles and an organic binder are easily punched and screen printed to produce hole and metal patterns, such that, when a number of these sheets are laminated in a stack and fired, they produce a ceramic monolithic part. This technology is now being applied in the development of microfluidic or "microreactor" systems for biotech and energy applications. One of the current limitations with this technology (due to a lack of easily available tooling) is hole formation, which is relatively large, and typically having a lower limit of 0.020" opening with 0.016" spacing on 0.010" thick tape. These dimensional constraints present challenges in powder containment, multiple parallel channel formation and uniform fluid distribution to multiple parallel channels in microreactor applications. To extend the useful lower dimensional limits for openings in laminated multilayer ceramics without changes in process tooling, it is proposed that arrays of openings be patterned and spatially offset onto successive green tapes, such that the stacking and lamination of the tapes result in a partial overlapping of the openings. The overlapping portions of the openings due to the patterned spatial offset on tape layers will have smaller dimensions and cross sectional areas compared to completely superimposed array of openings. Thus, the laminated multilayer ceramic structural element of "offset overlapping array of openings" yields dimensionally smaller openings, and provides a means of forming a "porous frit" for powder containment, filtration, gas mixing and/or distribution, and channel formation within a multilayer ceramic monolith.

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MULTILAYER CERAMIC STRUCTURAL ELEMENT for CATALYST CONTAINMENT, GAS DISTRIBUTION, or CHANNEL FORMATION

By Stephen P. Rogers, Daniel Zindel and Sonja Tasic

ABSTRACT

Multilayer ceramic technology provides a method for the manufacture of 3D monolithic structures that are thermally and chemically robust integrated systems with embedded electrical components and fluid flow channels and cavities. Thin sheets or tapes (0.007" 0.010" thick) containing ceramic particles and an organic binder are easily punched and screen printed to produce hole and metal patterns, such that, when a number of these sheets are laminated in a stack and fired, they produce a ceramic monolithic part. This technology is now being applied in the development of microfluidic or "microreactor" systems for biotech and energy applications. One of the current limitations with this technology (due to a lack of easily available tooling) is hole formation, which is relatively large, and typically having a lower limit of 0.020" opening with 0.016" spacing on 0.010" thick tape. These dimensional constraints present challenges in powder containment, multiple parallel channel formation and uniform fluid distribution to multiple parallel channels in microreactor applications. To extend the useful lower dimensional limits for openings in laminated multilayer ceramics without changes in process tooling, it is proposed that arrays of openings be patterned and spatially offset onto successive green tapes, such that the stacking and lamination of the tapes result in a partial overlapping of the openings. The overlapping portions of the openings due to the patterned spatial offset on tape layers will have smaller dimensions and cross sectional areas compared to completely superimposed array of openings. Thus, the laminated multilayer ceramic structural element of "offset overlapping array of openings" yields dimensionally smaller openings, and provides a means of forming a "porous frit" for powder containment, filtration, gas mixing and/or distribution, and channel formation within a multilayer ceramic monolith.

DESCRIPTION

Design of the laminated multilayer ceramic structural element "offset overlapping array of openings" involves alternating tape layers, "i", "ii", "iii", and so on. Ceramic layer i has a patterned array openings, and has the smallest dimensional openings and pitch for a combination of alternating layers. Layer ii has a patterned array of openings that are equal to or larger in size, or may be shaped differently, than the openings in layer i. As a preferred embodiment, an x- and/or y-direction offset of 0.5 to 0.75 layer i pitch dimension, will ideally, center layer ii patterned array of openings between adjacent layer i openings. Layer iii may be equal to i or have a third patterned offset array of openings. The structural element in Fig. 1 was demonstrated in a methanol steam reforming microreactor for gas distribution and catalyst powder containment. Different combinations of openin...