For all of our friends that feel a little uncertain when material data sheets are discussed and words like dielectric constant, Tg and coefficient of thermal expansion are thrown into the discussion, we have compiled a short cheat just for you.
Dk – Dielectric Constant – The way the electrical signal moves through the material from front to back.
Dissipation Factor – Loss Tangent – How much the signal dissipates or “leaks” out of the substrate. The higher the speed the higher the loss.
Coefficient of Thermal Expansion – Thermal fractional change in material for unit change in temperature.
Resistivity – How strongly the material resists current.
Tensile Strength – Relates to the rigidity of the material as well as the peel strength. How far can the material be stretched before permanent damage occurs.
Dimensional Stability – The tendency of material to change in the x and y dimensions when copper is etched away from the dielectric material or when exposed to temperature extremes.
Tg – Glass Transition Temperature – Temperature that material exhibits a change in physical characteristics. The resin changes from rigid or hard to a soft, rubber like material.
Td – Thermal Decomposition Temperature – Temperature at which the material weight changes by 5%. This parameter determines the thermal survivability of the resin material.
As always, if you have questions or would like additional information, please contact us! www.omnipcb.com
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