Waters Corp., a developer specializing in liquid chromatography, mass spectrometry and thermal analysis, has announced it will reorganize into three divisions: Waters, Micromass and Thermal Analysis Instruments. The Waters Div. will now fully integrate chromatography research and development, manufacturing and sales and marketing. John Nelson, who was promoted to president and COO of Waters Corp., will oversee the three operating divisions. Arthur Caputo has been promoted to president of the new Waters Div. . . . Joseph R. Cole has been promoted to vice president of worldwide sales at Multilink Technology Corp. . . . Harry H. Davoody was named president and COO of ST Assembly Test Services Ltd., effective Jan. 8. He was also appointed to the board. . . . Donald D. Jobe was elected to Merix Corp.'s board of directors.