Wiik was born in Norway in 1937. He moved to Germany in 1956 and after spending several years in the United States, joined the Hamburg laboratory in 1972. At DESY he was a member of the TASSO collaboration, one of four groups studying electron-positron collisions at the PETRA collider. In 1979 the TASSO collaboration won the race to observe the first experimental evidence for the gluon, the particle responsible for the strong force. Wiik was also given special responsibility for the superconducting proton ring at HERA, the first accelerator to collide electrons (or positrons) and protons.

HERA was successfully commissioned in 1991 and Wiik became director of DESY in 1993. He maintained his interest in superconducting accelerator technology and in 1997 DESY produced a 1100-page conceptual-design report for a superconducting 500 GeV electron-positron linear collider called TESLA.

A press release from DESY said that the laboratory learnt of Wiik's death with disbelief. "Words cannot express the shock and sadness that is felt by everyone. Our heartfelt sympathies and condolences go from each one of us to his wife and three children."

Brian Foster, spokesman for the ZEUS collaboration at HERA, said: "Bjorn was a great scientist, a great leader and a good friend to many of us. He will be sorely missed."