Finite element modeling of channel sag in LTCC

Abstract

Purpose -In microfluidic channel fabrication in low temperature co-fired ceramics (LTCC), one of the biggest challenges is the elimination of channel deformation during lamination. The purpose of this paper is to describe the expected deformation of the substrate and the sacrificial layer (starch powder and 3D printed UV polymerized material) during the lamination process of microfluidic structure fabrication. Design/methodology/approach -Uniaxial compression and Jenike shear test were used to obtain the mechanical parameters of starch sacrificial volume material (SVM). To determine the stress-strain characteristics of LTCC a uniaxial compression experiment was conducted. The shape of the laminated LTCC containing embedded channel was modeled by finite element method using the mechanical parameters obtained by the measurements. Findings -It was found that the choice of SVM plays an important role in channel deformation. A design rule is given considering the channel width and the choice of SVM based on the simulation results. Originality/value -Until now the lamination step of LTCC technology was only optimized in an empirical way.

Simulation Analysis of Microchannel Deformation during LTCC Warm Water Isostatic Pressing Process

“…3 distribution of the total displacement after unloading The Figure 3 shows that overall shrinkage occurs after unloading, the micro-channel deformation is relatively large, the main channels and the branch channels happens to a certain degree of collapse. Result shows that isostatic pressing process can provide uniform pressure to make the component overall deformation, keep a certain roughness, but for the component that embedded micro-channel network suffers larger deformation due to uniform pressure [5]. The displacement of micro-channels cross-section on the height direction UZ can be seen in Figure 4 and Figure 5.…”

“…Under the relative high pressure it is easier to produce deformation on the height direction and the deformation tends to be greater [3]. At the same time, the sag of the main channel with the width 2.2 mm is more significant than the branch channel with the width 1.0 mm, while the main channel has a large width-height ratio-aspect ratio than branch channel [5].…”

“…Micro-channel will collapse when lamination pressure exceed greatly [3]. The simplest model of green tape is of an elastic-plastic material [5]. Plastic deformation will produced when pressure exceeds the yield point of the green tape.…”

A review on amperometric-type immunosensors based on screen-printed electrodes

“…Screen printing techniques, regarded as a subset of thick-lm technology, are believed to have originated in China during the Song dynasty 67 and have their traces in the construction of the Great Wall of China as well as in ancient Egyptian cloth patterns. 68,69 Since 1950, screen printing techniques have been employed in the electronics industry for fabricating printed circuit boards. 70 SPEs fabricated by thick-lm technology 71 represent an attractive electrochemical sensing strip for the detection of several biological species, e.g.…”

Overview on low temperature co-fired ceramic sensors

“…LTCC technology makes it possible to process each of the tapes (layers) separately e.g. deposit onto them conductive paths, resistors, dielectrics, [1,2] machine channels, chambers [8] etc., and then bond single tapes together [9]. The possibility of the fabrication of electric vias between layers permits the manufacturing of multilayer electric boards and mechanical structures.…”