1996 Southwest Test WorkshopThe SWTW is the only IEEE sponsored technical forum for test professionals involved in microelectronic wafer level testing. It is a test workshop, where attendees have abundant opportunities to informally discuss topics of mutual concern. It is a practical conference, with a balanced mixture of current period manufacturing best practices and vendor ready-to-buy solutions to present day problems. There were eight consecutive technical sessions with 3 or 4 view foil presentations per session during the 2-1/2 day workshop. On Sunday, June 9, a special activity was organized for travelers that flew in Saturday to save money - a trip to the Scripps Institute of Oceanography. We provided a bus and admission to UC San Diego's Scripps Steven Birch Aquarium in La Jolla. The festivities officially began Sunday evening with the registration, a reception and Mexican Buffet Dinner. The panel discussion this year addressed "Probe Card Wear Out." Six manufacturing wafer sort experts detailed their own companies' procedures to identify probe card problems before they affected yields. The assertion that "probe cards never wear out, they are just maintained to death" was be hotly debated between card providers and the users-abusers. We videotaped this session and copies were handed out on Wednesday morning. The technical sessions began on Monday morning with three presentations on Radio Frequency Testing at the wafer level. These included test equipment issues and physical/mechanical interfaces, tradeoffs between cable and overhead probing, and a mini-tutorial describing the relationships between high frequency digital and RF terminology. The next session discussed vertical probing applications. Buckling beam or Cobra probe cards have come to be known as vertical probes. Four presentations were made to address the advances made with this technology and their application to area array die and to parallel, multi-site probing. Everyone knows that 50% of the value of a technical conference is in the informal attendee interactions. To facilitate this important aspect of SWTW, the entire workshop was bussed to the world famous San Diego Balboa Park. Tickets were also given out for admission to the Andrew H. Fleet Space Theater and Science Center. The attendees were bussed back to the hotel just in time to board the boat for the harbor cruise. Workshop members and their spouses got a chance to enjoy a three-hour dinner cruise circling Mission Bay. Our industry's ability to measure probe cards is just as important as our alleged ability to build them. Three presentations discussed two vendors' metrology equipments and an independent probe card evaluation laboratory being established by Sematech. Many companies are probing at temperature extremes and almost all have difficulties. Four presentations were made that described the experiences, lessons learned, and important equipment and material characteristics. Membrane probe card technology has been slowly and painfully developing for the past few years. Three presentations were made that discussed recent advances, and some real data illustrating high volume production viability was provided. The investments in probe operations seem insignificant compared to those of the wafer fabrication facilities that precede them. Nevertheless, improving their productivity is important, and this session had four presentations describing how probe floor physical layouts, material movement and handling procedures, and equipment they use affect their efficiencies. At the awards banquet, prizes for the best presentation, best data, best questions asked, and the infamous poorest disguised sales pitch. After dinner speaker Jerry Hutchenson, CEO of VLSI Research discussed the economic size, shape, and future of the wafer test industry. On the final day of the workshop, the probe potpourri session had two presentations on probe needle material characteristics and failure analysis, and an open discussion on full wafer level burn-in. The final four presentations will discussed issues involved with, and present examples of, very high pin count and fine pitch probe cards |