Proposal of a current measurement technique for each pin of a BGA package

In the consumer electronics field, the clock frequency of the system LSI (large-scale integration) is increasing significantly. To maintain operational stability, the impedance of the power distribution network, especially in the high frequency range, has to be reduced. This results in increased number of power supply or ground pins for an LSI package. The increased pin count will require a larger LSI package leading to a cost increase. In order to reduce costs, the number and placement of the power supply pins and ground pins have to be optimized and hence, the current on each power supply pins and ground pin should be monitored. We are therefore developing a new probe using a printed circuit board with embedded parts to monitor the high frequency current of each pin in a ball grid array (BGA) package. In this paper, we report on the structure of the new probe and its high-frequency current measurement results.