Application of Surface Mount Processes for Economical Production of High-Aspect-Ratio Microchannel Arrays

This paper reports on the feasibility of using surface mount technology (SMT) assembly processes and materials to produce highly parallel, high-aspect-ratio microchannel arrays. Experimental results show that the fabrication of high-aspectratio (> 40:1) microchannel arrays is possible using solder paste screen printing and reflow bonding. A simple model and empirical examination verifies that very little solder is wicked into the channel during reflow. The use of low bonding temperatures (under 300°C) and pressures results in well-aligned, parallel channels with low levels of warpage. Channel height variation within these microchannel arrays was measured to be less than ±1.2% of the overall mean channel height of 270.9 μm. Gravity effects on three-channel devices were found to be insignificant. The microlaminated devices were found to tolerate an air pressure of 1.72 bar (25 psi) without leakage, though it is expected that higher air pressures are possible as the devices were not tested to failure.