After the Apple Watch has been torn down by repair companies, now a deeper inspection of the S1 system-in-package has been performed, bringing to surface some interesting new details. Previous reports discovered that the S1 package that runs the Apple Watch comes with 512MB of RAM, a Broadcom Wi-Fi chip and an accelerometer/gyrometer from STMicroelectronics, among others.
Now, further investigation from Chipworks has revealed there are around 30 individual components inside the 26mm x 28mm S1 package, which the repair company refers to as "quite an accomplishment."
"Apple and/or their suppliers have designed and manufactured a 26 mm x 28 mm package that is very unique. Let's consider its construction for a moment. We have a common motherboard to which all of the components (wafer scale packages, PoPs, BGAs, etc.) have been attached. The entire motherboard, with all of its components, is then overmolded with a packaging compound containing silica or alumina spheres suspended in a resin. We see this same type of material in conventional IC packaging, but we have never observed this being used over a 26 mm x 28 mm motherboard."
Chipworks points out that Apple's APL0778 chip was fabricated on Samsung's 28-nanometer low power process. Measuring just 5.2 millimeters by 6.2 millimeters, the small processor is actually the largest component in the S1.
It has been discovered that longtime Apple supplier Cirrus was bumped from the Apple Watch in favor of audio codec and amplifier silicon from Maxim. Just like with the iPhone 6, NXP silicon makes up the NFC controller and the secure element. STMicroelectronics provides the Watch's six-axis accelerometer and gyroscope, as well as the encoder that powers the digital crown. When it comes to battery management, it seems that Texas Instruments is the maker responsible for that.