93 percent of union members at Samsung in South Korea approved the strike plan.
Unless a deal is reached with the employer, an 18-day strike is expected starting on May 21, Reuters reports.
The union wants, among other things, higher salaries and abolition of the bonus cap.
The strike could hit global semiconductor supply hard, as the AI boom in particular has driven up demand.
"I expect there will be production disruptions," Choi Seung-Ho, who leads the union, said last week.
