High aspect ratio silicon micromachined heat exchanger

The fabrication process for a silicon micro machined heat exchanger is descibed. A thin walled, 7 mu m, channel structure defined by vertical channels, 360 mu m deep and 220 mu m wide, anisotropically etched in < 110 >-silicon followed by a pn-etch stop process provided a heat exchanger module in the shape of a "square wave" corrugated membrane. The double sided processing provided vertical channels interdigitated from one side to the other giving a counter flow component with rear side fluid access from the front side. The design allows the stacking of multiple elements to obtain a unit with the desired heat sink capacity.