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.
Laminate Resin
Polymeric Matrix
Epoxies and cyanate esters function as laminate resin systems within printed circuit board fabrication to bind reinforcing woven glass fabrics under thermal compression. This chemical architecture establishes the continuous dielectric foundation of a multilayer assembly. Thermosetting formulations undergo irreversible crosslinking during pressing cycles to lock dimensional tolerances and prevent subsequent delamination.
Dielectric loss tangent properties are governed by the specific crosslink density achieved in this initial polymerization phase.
Curing Kinetics
Molecular transformation proceeds through controlled temperature ramps inside hydraulic presses where exothermic reactions dictate total cycle duration. Excess heat release during gelation induces internal stress concentrations that manifest as microvoids within the dielectric core. Catalyst concentrations must remain tightly bounded to prevent localized scorching during high pressure stages.
Void content measurements obtained via acoustic microscopy verify whether the polymerization network achieved full conversion before mechanical release.
Thermal Resistance
Glass transition temperature thresholds define the operational limit where the cured matrix transitions from a rigid solid into a viscoelastic state. High filler loadings reduce coefficient of thermal expansion values along the z axis to protect copper plated through holes from cyclic fatigue during wave soldering. Moisture absorption rates dictate how long an inner layer can sit in ambient shop floor conditions before baking becomes mandatory.
Delamination failure occurs when mechanical stresses from expanding entrapped water vapor exceed the interfacial adhesion strength between the resin and the glass reinforcement.