Apple reportedly intends to refresh its smartphone lineup next year with the thinnest iPhone ever, surpassing the 6.9mm thinness set by the iPhone 6 10 years ago.

The iPhone 17 Air (or iPhone 17 Slim) is likely to join the lineup next September as planned, although it will not be as thin as originally intended due to some reported battery issues.

According to a new report by the DigiTimes Asia website citing supply chain sources, the device has entered the new product introduction (NPI) phase at Foxconn, Apple's Taiwanese manufacturing partner.

The NPI stage is where design concepts begin to become reality. It is where Apple product engineers work with Foxconn's manufacturing team to figure out how the product will be assembled and to ensure that the approach is practical. At this stage, the design is largely fixed, with little room for change.

Once this is agreed upon, pilot production is conducted to ensure that the assembly process works and quality control is maintained across several devices before moving to the mass production process. This means that the slim model will be the thinnest model in the upcoming iPhone 17 family and is targeted for a September release.

For the third time for Apple, the iPhone Air will replace the poorly performing Plus model. It is rumored to be only 6 mm thick and will feature a 120 Hz screen and a single camera lens on the back.

If this 6mm figure is correct, it would certainly make it the thinnest iPhone ever, but it is worth noting that the latest iPad Pro is even thinner at 5.1mm, as the iPad has a much wider shell to accommodate the battery, and Apple is not willing to sacrifice the stamina needed to make the iPhone even thinner. Apple may have decided that it was not worth sacrificing the stamina needed to make the iPhone even thinner.

Interestingly, the DigiTimes report parallels the long-awaited foldable iPhone. If Apple succeeds in producing an ultra-thin iPhone, it would help in the development of a folding model.

In other words, every millimeter Apple can shave off is important. Nevertheless, this remains a long-term product, and the iPhone Flip is not expected to appear until 2026 or 2027.