Murata Manufacturing Co., the exclusive supplier of foldable circuits for Apple Inc.'s new iPhone lineup, is boosting its capacity to build the components on the view that demand will increase next year.

The company's MetroCirc circuit boards can be bent, making it easier to pack them into smartphones, including the latest iPhone X and 8 models. Factories are already operating at full capacity, forcing the Kyoto-based company to turn customers away, President Tsuneo Murata said in an interview.

The manufacturer's relationship with Apple was put to the test earlier this year when it struggled to keep up with orders for MetroCirc components. The company managed to meet its targets, but the rising cost of production forced it to cut its full-year profit outlook. While Murata said the problem has been solved, he declined to give specifics of the planned expansion.