Layer Material
Insulating resin sheets laminated onto a core substrate to form high-density sequential build-up layers provide the ultra-fine-line routing needed for high-performance semiconductor packages. Applying build-up films to a circuit board allows fabricators to bypass the routing limits of traditional glass-epoxy prepregs. This thin film features a uniform, glass-free composition that supports sub-ten-micron trace widths.
It forms a smooth dielectric surface that receives electroplated copper with excellent adhesion. These films are applied using vacuum lamination to prevent air entrapment.
Via Drilling
Laser systems easily drill through the glass-free resin to create microscopic blind and buried vias for interconnecting adjacent signal layers. The lack of glass fibers prevents laser beam deviation, ensuring high via registration accuracy. This drilling precision allows for smaller via pads and tighter routing density.
After drilling, the film undergoes desmear and chemical copper plating to establish electrical paths.
Interconnect Density
Substrates utilizing these films handle the dense pinouts of advanced microprocessors and graphics chips. Multiple layers of the film are sequentially added to each side of the core to build complex routing trees. This multi-layer construction minimizes crosstalk and manages return paths.
High-speed digital systems depend on these substrates to operate without signal degradation.
