OLED screens for iPhone 8 are proving significantly more difficult to mass-manufacture than Apple’s suppliers may have anticipated, with a Foxconn executive claiming high rejection rate for the sophisticated display panels due to “a special cutting” in them.

According to MyDrivers yesterday, Foxconn Vice President Luo Zhongsheng opined on Chinese social network Weibo that a low yield of the OLED screens is among the chief reasons why iPhone 8 buyers would have to pay a premium for the device.

“Cutting the display into this special shape looks really difficult, and the cost won’t be cheap,” reads his post. “I estimate that iPhone 8 won’t be cheap.”

iPhone 8 is widely believed to feature a notch in the middle of the iOS status bar at the top of its seamless OLED display in order to accommodate the front-facing camera and sensors.

The now-deleted post did not specify if “a special cutting” refers to the notch at the top of the OLED display. In manufacturing, yield is a measure of efficiency.

It’s defined as the number of units coming out of a process divided by the number of units going into that process over a specified period of time.

Despite being widely used on high-end Samsung devices, OLED panels are still difficult to produce in volume, resulting in high yields.

As an example, the yield rate on Samsung-made OLEDs for iPhone 8 is believed to be about 60 percent. By comparison, the production yield rate on Samsung-built OLED panels for its own devices like Galaxy S8 is about 80 percent.

Mockup courtesy of Max Rudberg.