Liquid crystalline polymers (LCPs) are a unique class of thermoplastics that contain primarily benzene rings in the backbone with molecules that are stiff, rod like structures organized in large parallel arrays. They are highly crystalline, inherently flame retardant, thermotropic (melt-orienting) thermoplastics. While similar to semi-crystalline polymers, LCPs have distinctive attributes. Conventional semi-crystalline polymers when melted have a random structure, which, as they cool, form highly ordered crystalline regions surrounded by an amorphous matrix. LCP molecules remain well ordered even in the melt and slide past each other easily under shear. The result is very low melt viscosity making it easy to fill extremely thin walls and to replicate intricate features. They exhibit little or no shrinkage in the flow direction and require very little time to set-up or solidify. For high precision, thin walled parts that may need to survive high heat exposure, many designers and processors specify liquid crystal polymers.