Friedrich Tinner was given a two-year suspended sentence Tuesday, SwissInfo.ch reported. His sons, Urs and Marco, were given sentences of 50 months and 41 months, effectively time served.
They also are to pay fines and legal costs.
The Tinners were convicted of violating Swiss laws on exporting military material. Investigators say they worked with Abdul Qadeer Khan, the "father of Pakistan's nuclear bomb," who also aided Iran, Iraq, Libya and North Korea with their nuclear programs.