Made by either Samsung or LG
In the iPhone XS there is a 5.8-inch, 2,436-pixel by 1,125-pixel OLED display that is very similar to the display in the previous model.
The XS Max display is, as you might have guessed, bigger: 6.5 inches, and 2,688 pixels by 1,242 pixels.
Earpiece speaker assembly
This group of components includes an earpiece, loudspeaker, microphone, ambient light sensor, flood illuminator (produces an infrared flash in conjunction with the facial recognition sytem) and proximity sensor.
The assembly is bundled to the backside of the display. These are nearly the same in both models.
In both models, there is a 12-megapixel, dual wide-angle/telephoto camera with 2x optical zoom.
The lens cover is made of hard sapphire crystal, like the glass in luxury watches.
This is the camera used for facial recognition and video calling.
The standard front-facing camera has a lower resolution than the back-facing camera.
The dot projector projects an infrared dot grid on the user’s face…
…and the infrared camera reads the dot map to identify the owner.
Logic board (top)
The logic board is made up of integrated circuits on three faces that are stacked to save space.
Toshiba flash memory is used for up to 512 gigabytes of storage.
Apple audio codec from Cirrus Logic is used to convert digital signals to analog and back again. When you talk into the phone it comes in as analog and must be changed to digital for electronics to process it.
Logic board (top underside)
Apple A12 Bionic chip, the phone’s central processing unit, deals with basic functions and hands off other tasks to various chips. The chip has a neural engine designed to handle machine learning, which can enhance photos, gaming and augmented reality.
ST Microelectronics power circuit handles the phone’s components with differing power requirements.
Apple audio amplifiers, two for stereo and one for touch interaction.
Manufactured by Sunwoda Electronics
In the XS, this L-shaped 2,659 milliamp hour (mAh) battery, new this year, has less capacity than its predecessor, which had 2,716 mAh. Despite this, the XS ran longer than last year’s iPhone X in the Journal’s battery testing.
The XS Max has two batteries that are configured into an L shape, like the previous version, with 3,179 mAh of capacity. In our testing, that translated into 13 hours of Netflix streaming.
Nano SIM card reader
SIM cards store information that identifies your phone to the cellular network. If your carrier doesn’t support the eSIM chip built into the logic board, you can swap SIM cards in this slot for additional phone lines.
This is a vibration motor that provides tactile sensations when the phone is performing certain actions.
This combines with the earpiece speaker for stereo sound without headphones.
Lightning cable connector
A cable joins with the phone here for charging and adding accessories.
Wireless charging coil
Apple added wireless charging capabilities to its new phones last year. When the phone is placed on a Qi-certified wireless charger, the charger uses magnetic induction to interact with this charging coil.
The back of the iPhone is glass to allow the magnetic induction to work.
Source : https://www.wsj.com/graphics/iphone-teardown/