High defect rate observed in iPhone Duo production

According to reports from Jiemian News citing supply chain sources, Apple's first foldable iPhone Duo smartphone is facing serious difficulties in mass production. Currently, the yield rate on Foxconn assembly lines is just slightly above 60 percent, highlighting the complex technological hurdles manufacturers are facing. This was reported by Ixbt.com news outlet.

Experts note that this issue is not tied to a single defect, but rather the need to fully calibrate the entire production system for a new type of device. Since the iPhone Duo is Apple's first mass-market foldable, Foxconn is required to coordinate equipment, technological processes, and assembly parameters simultaneously. If current quality requirements remain unchanged, it could take six months to a year to reach stable mass production levels.

Technical complexities and the perfect fold

The main focus in production is on making the crease on the internal display as invisible as possible. To achieve this, not only is special nanostructured UTG glass used, but also a complex hinge system consisting of over a hundred components. Each element requires high precision, as even the slightest deviation can leave a noticeable mark on the display or cause it to sag.

The device's chassis is designed to be extremely thin, measuring just 5.2 millimeters when unfolded. Due to the hinge occupying the center, the batteries, system board, and cooling system are placed on either side. Chinese partner companies, including Lens Technology, Lingyi, and Zhuhai Guanyu, are actively involved in this process by supplying critical parts, including UTG glass and battery cells.

Delays in sales and plans

Such technological difficulties in the process explain why the gap between the presentation and the start of sales is significantly longer than usual. For the iPhone Duo unveiled on September 10, pre-orders are scheduled to open on October 16, with sales starting on October 23. Thus, the period between the announcement and the market release is 43 days, whereas for typical flagships, this period is usually around ten days.

According to sources, Apple plans to build a global inventory of approximately 6–8 million iPhone Duo units throughout 2026. Of this, over 5 million devices are intended for delivery to retail partners. For comparison, some Pro and Pro Max models reach 20–30 million units shipped over their entire lifecycle.