Ultratech Inc., a San Jose, Calif., supplier of photolithography systems used to manufacture semiconductors and nanotechnology devices, announced that ChipMOS Technologies Ltd. has purchased its Saturn Spectrum 3e advanced packaging lithography tool. ChipMOS, a semiconductor testing and packaging company based in Bermuda, intends to offer gold-bumping services from its Taiwan, China, facility for its flat panel display-driver device customers.   . . .   LEDtronics, a Torrance, Calif., supplier of LED lamps, clusters and arrays, has appointed John Henckel as its new sales representative for Northern Europe (Denmark, Sweden, Norway, Finland, the Netherlands, Germany and Austria).   . . .   CTI Molecular Imaging Inc. and Siemens Medical Solutions USA Inc. have signed a definitive agreement to restructure and align their resources for the sales and marketing of positron emission tomography (PET) and PET/computed tomography (CT) equipment manufactured by CPS Innovations, a joint venture between the two companies. The companies said they will also develop new clinical applications for molecular imaging. Scanner sales and service activities outside the US, except for South Korea and Japan, will be performed exclusively by Siemens, and each company will retain its own field service personnel in the US. All PET and PET/CT scanners sold under this new agreement will be marketed under the Siemens ECAT and biograph labels. As part of the agreement, Siemens will market other CTI Molecular Imaging products and services, including FDG (fluorine-18 fluorodeoxyglucose, a PET radiotracer) and cyclotrons.