레이저 애칭으로 가공된 미세홈의 모세관 특성평가

Investigation of capillary characteristics of laser-etched microgrooves

An optical fiber-based laser etching technique is used to fabricate microgrooves on stainless steel foil. A nozzle structure that produces an etchant jet is designed and utilized in experiments so that the application of laser etching technique can be extended to arbitrary size workpiece. The fabricated microgrooves can be applied for the wick-structure of micro heat pipes through which the circulation of working fluid occurs by capillary pressure. The capillary pressure of the microgrooves depends on the parameters including working fluid, groove size and shape, and surface roughness, and directly influences on the performance of micro heat pipes. The capillary flow velocity for varying groove parameters is measured to examine the relationship between groove parameters and cooling capacity of micro heat pipes.