The National Samsung Electronics Labor Union (NSELU) had been staging a three-day strike since Monday after their negotiations with management fell apart.
The union originally planned a second five-day walkout starting next Monday but changed course, declaring an indefinite, full-fledged stoppage beginning Wednesday. The union denounced management's unwillingness to engage in dialogue.
The NSELU, the largest in-house union with 31,000 members, represents about 24.8 percent of Samsung Electronics' total workforce of about 125,000 employees.
The union's demands include a one-day union foundation holiday, a 3.5 percent average wage increase for all members, improvements to the bonus system, and compensation for economic losses due to the strike.
The NSELU proclaimed its aim to disrupt production, asserting that despite automation, the absence of personnel for equipment and inspection will inevitably affect output.
However, the company maintains that despite the strike, production continues normally without disruption.
The union said 6,540 members have expressed their intention to participate in the strike, with 5,211 belonging to the semiconductor equipment, manufacturing, and development sectors.
The union has instructed its members not to report for work until further notice from the executive committee.