The National Samsung Electronics Union (NSEU), the largest among multiple Samsung Electronics’ labor unions went on a three-day strike for the first time in its history on July 8, following collective annual leaves in June. The labor union said it was looking to disrupt production, but the management said there was no disruption on the first day.

The first strike since the foundation of Samsung Electronics in 1969 came only three days after the management announced a second-quarter earnings surprise that exceeded 10 trillion won.

The NSEU explained that it had been negotiating with the management since January, but none of its demands had been accepted by the management.

“Even though Samsung Electronics’ annual operating profit has reached 40 trillion won (approximately $29.6 billion), it is forcing employees to sacrifice themselves in the name of coping with a crisis,” said Son Woo-mok, chairman of the NSEU. “The management said that they could not even pay incentive bonuses, but executives took home 2.9 billion won in performance bonuses.”

In response to the labor union’s claim that the goal of the strike by more than 6,500 of its 30,000 members was to disrupt production, Samsung Electronics said that only 3,000 workers participated in the walkout and that there was no disruption to production at the time.

However, due to the nature of semiconductor production lines that they cannot stop, there are concerns over a prolonged strike.

Although the NSEU is the largest among Samsung Electronics labor unions, representing about a quarter of Samsung Electronics’ total employees, many of its members are known to be semiconductor production workers. In particular, the labor union said that more than 5,000 of its members who announced their intention to strike are production workers such as those for equipment and manufacturing.

The labor union said that if labor-management negotiations hammer out a deal after the three-day strike, the labor union will continue with a second strike.