Background
As the demand for the portable handheld products and devices, such as smart phones and tablets, is strong and increasing, high density and high performance packaging technologies have been required for today's mobile device applications. Coreless substrate with embedded trace technology would definitely meet the demands of high functionality in small packages. Embedded trace technology provides superior fine-line capability and minimize the total size of products (1),(2),(3). Fig. 1 shows the comparison of embedded trace substrate (ETS) and conventional FCCSP substrate. Fig. 2 shows the fine lines (line width/space: 10 um/10 um) embedded in Prepreg. ETS with coreless substrate technology eliminates a thick core and provides superior electrical performance. Fig. 3 shows the simulated electrical performance comparison between ETS and normal FCCSP package, ETS has less signal power loss compare to typical 2 layer FCCSP package, especially on the high frequency range.
Embedded trace substrate and conventional substrate (2 layer FCCSP substrate)
Embedded traces in prepreg
Electrical performance comparison between FC-ETS and conventional fccsp