What engineers typically see as chips and semiconductors are packaged are dies that have very fine wires connected to them that connect to pins and have been enclosed in some material, often epoxy.
Dies are often tested for functionality before they are packaged to save money and time, eliminating the packaging of a faulty die into a chip. To test a die you need a machine that can make many contacts with the points on the die called micro bumps. These micro bumps are very small, smaller than the head of a pin. The particular dies discussed here contain bumps with a standard layout and size. The probe cards possess many tiny electrical probes used in automated test equipment to ensure reliable contact with the bumps. Large array have numerous contact points and fine pitch which means they are very closely spaced together.
In the context of pre-, mid-, and post-bond testing of dies in a 2.5D- and 3D-stacked IC, a fully automatic test system for characterizing advanced probe cards able to probe on large-array fine-pitch micro-bumps (such as JEDEC’s Wide-I/O Mobile DRAM interfaces) has been specified, developed, installed, and brought into full operation. The system is based on a CM300 probe station from Cascade Microtech (now FormFactor) and National Instruments PXI test instrumentation and complemented by in-house-developed software for automatic test generation and data analysis and visualization. The system is successfully used in conjunction with FormFactor’s Pyramid Probe RBI probe technology on Wide-I/O 1 and 2 micro-bump arrays on ø300mm wafers designed and manufactured by imec. This presentation describes the various system components in hardware and software, and experimental results obtained with several test wafers.
Watch this clip from National Instruments' webinar "A Fully Automatic Test System for Characterizing Wide-I/O Micro-Bump Probe Cards".
To learn more from the expert presenters, view the webinar in its entirety.