Cooling rate limitations in the diffusion bonding of large microchannel arrays

A significant barrier to the diffusion bonding of large (i.e. 600 mm) microchannel devices is the large capital investment required to setup production. This large capital investment extends from long heating and cooling cycles leading to poor production capacities. Empirical studies in industry have shown that cooling rate is limited by the warpage of microchannel laminae which is believed to be caused by thermal buckling. In this thesis, the limits of cooling rates during the diffusion bonding of microchannel laminae were investigated. Findings confirm that cooling rates are limited by the thermal buckling of free-standing microchannel laminae during cooling of the device. Finite element analyses (FEA) of the transient thermal and static stress behaviors of these microchannel laminae were conducted to identify the maximum cooling rates for different lamina thicknesses. FEA results were used to extrapolate implications for microchannel production