Apple’s secret ingredient for making the iPhone thinner just got delayed to 2026

Back in October 2023, Ming-Chi Kuo reported that Apple was exploring the use of resin-coated copper (RCC) components for the iPhone’s logic board in an effort to save space within as the outside thickness was reduced. However, a new report from the same source claims that won’t be happening after all.

In a post on X (formerly Twitter), Kuo says Apple won’t be using the new material in the iPhone 17 due to supplier Ajinomoto’s “inability to meet Apple’s high-quality requirements.” In October, Kuo reported that if Ajinomoto could improve the RCC material before the third quarter of this year, Apple would use it in “the 2025 new high-end iPhone 17 models.”

The new high-end iPhone 17 is rumored to be a slimmer model with a larger screen size and a new design. The use of RCC was presumably one of the ways Apple was able to make the phone thinner, as Kuo explains that RCC “can reduce the thickness of the mainboard (i.e., it can save internal space) and make the drilling process easier because it’s fiberglass-free.”

Kuo doesn’t speculate whether the shift changes Apple’s plan for the iPhone 17, but with far less internal space than an iPad or Mac, it could force Apple to pivot to a different plan while delaying the new slimmer iPhone model to 2026.