COMPARISON OF PCB MATERIALS FOR HIGH SPEED AND HDI BOARDS

The most powerful, modern and easy-to-use PCB design tool for advanced
electronics. Use any PCB material and prepare your board for
manufacturing with Altium Designer.

Any PCB stackup you create for your circuit board will include multiple materials. Many different
materials will be used during the PCB manufacturing. The materials you
choose will determine power/signal loss, interconnect impedance,
temperature rise, copper surface roughness, and temperature rise in your
PCB. Not every base material is ideal for every application, so you’ll
need to pick just the right base material for your PCB stackup to
balance performance in these different areas.

With a thorough comparison of PCB materials, you can determine the best base material to
use for your next system. Once you determine the best material to use
for your circuit boards, the PCB stackup design and analysis tools in
Altium Designer help you create a PCB layout for high speed circuit
boards or HDI designs. Here is a comparison of PCB materials to help you
choose the right base material for your circuit boards.
Fabricators continue to discover materials better suited to high speed circuit
boards, HDI circuit boards, and high temperature environments. The
various material properties above affect how high speed signals
propagate in a substrate due to dispersion, as well as how the disperse
heat and withstand mechanical shock. Some of these materials are
suitable for microwave and mmWave devices, or for use in high
temperature environments, but they are more expensive to produce. Your
best bet in choosing a material is to start with FR4 and evaluate
whether this material will be suitable for your application.

The industry primarily uses grade FR4 nonconductive material between layers
of copper to build printed circuit boards. FR4 is a NEMA grade
designation for glass-reinforced epoxy laminate material. The
designation represents the ratio of fiber to resin and indicates
characteristics such as flame retardant, dielectric constant, loss
factor, tensile strength, shear strength, glass transition temperature,
and z-axis expansion coefficient. FR4 is flame retardant making it
suitable for safety requirements, and it is robust in varying
temperature and humidity environments, increasing the quality of
performance.

The major material components of PCBs are the polymer resin (dielectric material) with or without fillers,
reinforcement, and metal foil. To form a PCB, alternate layers of
dielectric, with or without reinforcement, are stacked in between the
copper foil layers. The majority of the materials are epoxy, but some
are BT, PPE, cyanate ester, and modified acrylates. The structure of a
typical epoxy PCB laminate is shown above.