Earlier today we covered a Ming-Chi Kuo research report regarding Sunny Optical to renter Apple's iPhone supply chain starting with the iPhone 16 and be the CCM supplier for M5-based MacBooks in 2025. A second report has now surfaced regarding the iPhone's mainboard switching to Resin Coated Copper (RCC) material in 2025. Kuo notes the following:  

• 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. However, RCC will not be adopted in the 2024 iPhone 16 due to its fragile characteristics and inability to pass drop tests.
• Currently, Ajinomoto is the leading supplier of RCC material. If Apple and Ajinomoto can improve the RCC material before 3Q24, the 2025 new high-end iPhone 17 models will use it.

Information surfaced last year stating that the current copper-clad laminate (CCL) will be partially replaced with resin-coated copper (RCC), aiming to reduce the size and thickness of the mainboard. This upgrade is expected to enhance electronic signal transmission efficiency, reduce energy consumption, and save internal space, providing more room for increased battery capacity.

The main difference between RCC and traditional CCL lies in their structure. RCC eliminates one layer of fiberglass cloth, significantly reducing the overall thickness of the PCB. It also simplifies the manufacturing process and improves the laser drilling yield. In terms of component performance, RCC allows for further reduction in line width and spacing of circuit wiring based on SLP, reducing the spacing between various passive and active components on the board. It even enables the embedding of some passive components, thereby saving space required for surface mount technology (SMT) processes. All these upgrades contribute to greater power efficiency and improved performance in end devices.