Electrical characterization of a 500 MHz frequency EBGA package

We developed a 420-ball enhanced BGA (EBGA) package that can accommodate a 500 MHz ASIC with 15 W power consumption. This package uses a low voltage differential signal with 400 mV full amplitude and 240 ps risetime as its highest speed signal, and consists of 8 pairs of differential signals. Each pair is composed of 2 signals with an isometric length. Two pairs have an identical length and form a channel, i.e. a parallel transmission path. This package has a nonstub configuration using electroless nickel and gold plating. This package also has a short ground loop running on the sidewall of the cavity. A time domain waveform was used for simulation of the electrical characteristics of this package. Then, the time domain waveform in an actual package was measured at risetime of 120 and 240 ps. As a result, the simulated time domain waveform agreed well with the measurements. We confirmed that the electrical performance of this package allows accommodation of a 500 MHz ASIC, and can achieve parallel transmission in a 500 MHz system.