Evaluation and verification of enhanced electrical performance of advanced coreless flip-chip BGA package with warpage measurement data

In this paper, the 8+1-layer coreless substrate of fcBGA will be introduced, which was revised from the 12-layer core substrate. This coreless substrate was manufactured in Shinko using an advanced ABF film (GZ41) having low CTE for lower warpage and better assembly performance. To evaluate and verify the electrical performance, the fabricated coreless substrate was measured for S- and Z-parameters in frequency-domain and measured for differential TDR impedance and eye-diagram & timing jitter histogram in time-domain. The simulated and measured results were compared with the simulated results of the 12-layer core substrate for evaluation of the improvement from signal/power integrity. In order to evaluate the assembly performance of the coreless substrate, the warpage data and basic material data (Tg, CTE) were measured and demonstrated for die attach area and non-die area.