iPhone Duo production challenges

The production of the iPhone Duo is moving forward, but a large number of devices are expected to be discarded due to quality issues, according to a source familiar with Foxconn's supply chain. The overall assembly yield is just over 60 percent, meaning almost 40 percent of the smartphones built will not be sellable, which is a major loss for both the factories and Apple.

High rate of unsellable devices

This high rate of unsellable devices will likely lead to further delays in product deliveries. The main issue stems from difficulties in manufacturing the hinges and the back panel of the iPhone Duo. These components indicate that the mechanical hinge Apple has chosen introduces significant challenges during the device's assembly.

Samsung's foldable smartphone experience

Samsung's experience in manufacturing foldable smartphones offers useful context. The company launched its first Galaxy Fold in 2019 and has since refined the design of its screens and closing mechanisms. Samsung eventually eliminated the gap between the two screens at the hinge level after facing competition from Honor.

Samsung's successful improvements

Samsung's goal was to fix the "gap" issue between the two screens and also to improve the overall smartphone design. This strategy was successful with the Z Fold 7 and its successors. Samsung has gained valuable experience by releasing foldable smartphones annually, reaching a peak with more complex models like the Galaxy Z TriFold, which features a second hinge.

Samsung's advanced manufacturing techniques

On the Galaxy Z TriFold, the assembly of the two different-sized hinges relies on automated systems. Samsung also uses 3D laser scanning to check the screen surface and X-ray tomography to inspect the flexible printed circuit before it is assembled with the panel. During durability tests, the main screen undergoes 200,000 folding cycles to ensure reliability.

Apple's potential for device replacement

Apple will therefore have to deal with a significant number of unusable devices for the first version of the iPhone Duo. Although pessimism may not be warranted, there is a risk that users might need to replace the iPhone Duo relatively soon after purchasing it.