| U |
uranium |
| UBM |
under-bump metallurgy |
| UCL |
upper confidence limit; upper control limit |
| UF |
ultra-filtration |
| UHF |
ultrahigh frequency |
| UHP |
ultrahigh purity |
| UHV |
ultrahigh vacuum |
| UID |
user identification |
| ULA |
uncommitted logic array |
| ULK |
ultralow-k |
| ULPA |
ultralow particulate air |
| ULSI |
ultralarge-scale integration uph units per hour |
| UPW |
ultrapure water |
| USART |
universal synchronous/ asynchronous receiver/transmitter |
| USOP |
ultrasmall outline package |
| Utt |
unattenuated |
| UV |
ultraviolet |
|