Now we are removing the thin copper film that seems connecting the main PCB and the structured light part
We can also see the cables for the front camera, TOF proximity sensor, structured light ect here, the layout is really dense
We have lifted these cables, detached from the main PCB
The 3D structured light system on Mi 8 EE is a bit different from the iPhone X and the OPPO Find X
The coded structured light does not need to undergo DOE diffraction, and it is not pseudo-random on the human face like on iPhone X.
By projecting 33,000 coded dot array for creating 3D facial model at the millimeter level form a coding pattern
They are different on the principles
For 3D coded structured light system, it needs a decoding process, while for the random spot structured light solution, it matches the 3D info directly
In regarding the power consumption, the random spot structured light solution is lower than the coded structured light while the efficiency is higher
However, we found that Mi 8 EE only uses the 3D structured light system for unlocking and Animoj, not the payment
When we removing the screws on this decorative plate we said the screw shape is a bit different from the others
They are not only for decoration but also for fixing the PCB purpose
You see we are now removing the last screw on the upper mainboard, which is just a normal shape screw, we finally removed them on the plate!
You can see the different shapes on the screws, the right is the normal one from Mi8, the left from Mi 8 EE
However at this stage we got a bit confused as it's totally different the Mi 8 we tore down before, literally redesigned the whole layout on Mi 8 EE
We won't be able to remove the mainboard though we removed all the screws, why?
We can see these three screw washers, they are probably 2 layers, they are connected to the end of the phone like I'm showing you
And we can see the battery is on it
They are tightly connected, have to remove the battery first, this layout is very complicate
Not very common among Android phones
Normally we can lift up this end and pull out but the difficulty part is we see the 3D structured light module are here connected to each other
While the other end has three screw washers we showed previously connected to the body as well, so it's tricky to take out the PCB board
So we remove the battery first, here is one of the most concerns you may have: why the battery capacity became less to 3000 mAh?
We are showing you now, it is 3000 mAh
Why it becomes less we assume it may affect by the PCB length or have something under the battery that pushes the battery has less volumn
We better remove from the bottom, bc if we just take the battery rashly, it might damage other components
After removing all the screws, we can remove the chin now
Can we see something that's really being hidden under the battery?
Yep, if we take a closer look, we can see something's under there, it is a layer of metal
That metal layer lies under the battery, which proves our latter previous assumption for the less capacity battery
This has been confirmed by official Xiaomi staff too: the length of PCB is the same as on Mi 8 standard version
So there is one possibility, the battery gets thinner
Why becomes thinner, bc there is a metal layer under the battery, I'm so smart, right?!
But here is another question? Why they placed a metal layer there? Can you guess?
I guess there are two reasons, one is it has this in-display fingerprint sensor, I remember when iVankr tore down the vivo Nex, which features the same as MI 8 EE,
there is one metal layer too, I guess you have to leave the space for the sensor
The second I guess bc on Mi 8 EE it features this pressure sensitive screen, that means you need the vibration unit
That unit, on one hand, it needs space
On the other hand, it may need a metal plate structure to connect with the phone middle frame that could be able to support itself
Thus to pass the vibration to the screen, remember the acoustic screen on Nex? Same principle
So I guess that's the two reasons for Mi 8 EE and Nex why they need a metal plate under the battery