In this research, a robust process was systematically developed for the rework of large I/O BGAs that are used on assemblies within computer networking equipment. The assemblies considered in this research were large high-density boards that were populated with multiple different BGAs.

First, the equipment used was thoroughly characterized. Component removal and replacement profiles were developed for a variety of BGA components ranging from micro-BGAs to large, high I/O BGA components.

The knowledge gathered through this research was captured in a personal computer based Decision Support System (DSS). The DSS, consisting of three functional modules, helps an engineer set-up the rework station and rework a BGA assembly. The functional modules within the DSS are process knowledge and instructions, process and profile recommendation tool, and supporting data modification tool. All the thermal profiles developed were stored in a database for use at a later date.

High Speed High Density PCB design - Subhash Pochareddy

A part of this project establishes a knowledge base that enables the prediction of controlled impedance and propagation delay times for the present-day high-speed PCBs. A 2-dimensional field solver will be used for this purpose. A database of standard PCB stack-ups will be developed by keeping in view the electrical and manufacturing issues involved. Another part of this project deals with cost comparison between conventional and High Density Interconnect (HDI) PCB manufacturing technologies. A software tool will be developed for estimating the benefits in routing that different HDI technologies can offer. Software models and databases will be developed to capture all the results of this project.