Apple AirPods Teardown
Freddie got an early morning start to the line at the Apple store today and got his hands on some AirPods.
After about thirty seconds of evaluating how to set them up, hearing their audio quality, and experiencing the nice little features like auto-pausing when removing from your ear, he determined it was time to tear them down and see what they’re made of.
It looks like there are five magnets in the charging/carrying case.
Freddie started by popping off the bottom where the charge contacts are, but realized that they probably didn’t intend to assemble the Pods from the bottom
He changed strategies and cut down the visible seam on the top of the Pods, revealing a continuous folded flexible circuit board.
Part of the flexible circuit board is adhered to the back of the speaker, and the other part is nestled neatly into the main housing.
Freddie desoldered the two speaker contacts to remove the speaker. Next to the contacts is a thin flex that leads to the outer-ear proximity (IR?) sensor. That flex got severed to pull the speaker off and away from the main body.
- Part number CY8C4146FNI-S443, PSoC by Cypress
- Part number 343500130 BPK828.00 B2800P SS, suspected Broadcom
- Part marking 4A6U, suspected PMIC
With the circuit board free you can see the dense and extensive testpoint strategy.
Nested inside the main body is the continuing flex circuit board with more densely components.
- Part marking MAX T 98730EWJ 9 641 RY E, some chip by Maxim
- Part marking 906 LA, suspected accelerometer/gyro/IMU
With the flex circuit board pulled back on the main body, you can see the second proximity sensor, and by the looks of the two windows on the top it about confirms it’s IR.
Even more remarkable is the double-sided assembly. Here’s the other side of the flex. Note the super-mini antenna connector!
- Part markings 6 41, no idea what this is
- Part markings TPS743, Texas Instruments and probably custom
And the same flexible circuit board continues underneath yet another fold! Now he’s reached some RTV-like potting material and some hard, black plastic bits that have the cutest little heat stakes!
Wrestling with the potting material was not the right way to go. He cut down the shaft to expose the battery and the remaining bits of the flex, including the mic on the bottom (part markings GWM1). And removing the hard, black plastic bits revealed a second mic at the top of the battery, presumably for noise cancelling.
Laying the flexible circuit board out flat really shows how many intricate and delicate folds are involved in assembling the AirPods. Another remarkable bit is that they decided to run the antenna down the length of the metal battery which is normally bad practice, though I’m sure Apple has some magician RF engineers.
Finally, while other folks in the wireless-and-tetherless headphone space have solved the audio syncing problem between two independent earpieces using Bluetooth and NFMI, Apple has found a way to do it with only Bluetooth.
One more interesting note: That Cypress IC is a 0.35mm pitch CSP! Mindtribe has been trying to source it for a project around here but it’s been hard to find for at least a month now, and now we know why!