[6] By the early 1970s, Bill Hugle's role in Siliconix had largely diminished as he began focusing on a political career as the Democratic nominee for California's 12th congressional district.

Lee remained principally responsible for Siliconix's day-to-day operations until the mid-1980s, when he expanded the company's executive leadership.

[11][2]: B-10  Bill Hugle lost the nomination in 1972 and was later charged by the Federal Bureau of Investigation (FBI) in 1983 of committing espionage in collaboration with a spy for the Polish People's Republic in the early 1970s.

[2]: B-1  By the late 1980s, however, sales began to flounder, and a patent infringement suit lost against International Rectifier forced Siliconix to file for Chapter 11 bankruptcy in 1989.

[14] In 1997, Vishay started to buy Siliconix stock from various shareholders and practically completed the acquisition of the entire company by 2005.