Hydrodynamic Shear Driven Inner Layer Copper Trace Washout in Ultra Thin Micro Channels
Controlling wet-process nozzle velocity below two meters per second prevents hydrodynamic trace stripping on ultra-thin inner layer copper channels.
Microchannels
Fluid Pathway
Conduits with at least one dimension in the range of one to one hundred micrometers facilitate the precise delivery or extraction of fluids. In advanced cooling systems for high power semiconductors, microchannels integrated into the substrate or heat sink increase the surface area for heat transfer. These small structures allow for efficient thermal management in compact electronic assemblies.
The design often involves complex etched or machined patterns.
Laminar Flow
Fluid behavior in restricted geometries is dominated by viscous forces rather than inertia. Because the reynolds number in microchannels is typically very low, the flow remains laminar and predictable. This characteristic allows for precise modeling of pressure drops and heat dissipation rates.
However, the small cross section also increases the risk of blockage from particulate matter in the coolant. Specialized filtration and smooth internal surfaces are required to maintain long term reliability. The high surface to volume ratio ensures that heat is removed rapidly from the heat source.
Manufacturing Method
Fabrication of these structures uses high resolution techniques borrowed from the semiconductor industry. Direct laser ablation or deep reactive ion etching creates microchannels with high aspect ratios in silicon or ceramic substrates. These methods must maintain tight tolerances to ensure uniform flow across the entire array.
Any variation in channel width leads to uneven cooling and potential hotspots on the active component.