Skip to main content

Repair guides and disassembly information for the 16-inch MacBook Pro released in October of 2021, featuring Apple-designed M1 Pro and M1 Max SoCs. Model A2485.

50 Questions View all

The bound type of metal pressure springs in touchpad (for experts)

Dear experts, on mbp touchpads with taptic engine, the glass layer and sensor layer are attached each other with adhesives. And as you can see in the image below, these 2 adhered layers float on 4 metal springs which behave as pressure sensor and activate the taptic engine according to pressure level.

At this point how the top layer (glass+sensor) is connected or attached with these 4 springs? Does manufacturer use the same strong adhesives for contact points of these springs and the layer over them?

Can a strong horizontal force or shear force damage the bound and dislocate/slide the top layer over metal springs?

Kind regards...

Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment

1 Answer

Chosen Solution

Here's a big surprise! There is no moving parts with this series TouchPad (a.k.a. Trackpad)

The glass plate has layers under it which deflect translating the finger movement across it (X-Y) as well as pressure (Z) this is all through capacitance within the plate and with the conductive grid within it that flex's.

Linus Tech Tips - Haptic Touchpad Design

You are feeling taptic engines force for feedback.

Update (06/13/2022)

OK, I think I see the confusion, the question is how is the sandwich held together and the second part can this be sheared off.

The metal pedals points are glued to the top segment with cyanoacrylate glue there is no flex in the bond. There is really no way for the top section to shift (shear off) remember there is a depression where the assembly is held.

Block Image

Why such concerns? I haven't see any fail in that way I have seen something dropped cracking the glass and the amount of force also dislodged the adhesion but at that point the part was beyond use.

Was this answer helpful?

Score 1


I know the Taptic Engine vibration simulates the click feeling but there is another detail: as you can see in the video below, there are 4 pressure pedals or spring which detect the pressure. They are connected to the top layer in 4 contact points. The glass and sensor layers are set on these pedals. So there must be a bound between these contact points. @danj


The last question: as you can see in the image below link, the 4 metal springs are the part of a metal strip/band unibody, at this point does this complete unibody is attached to the upper layer with adhesive with all areas of strip/band or only attached with only 4 touchpoints on pedals/springs? @danj



The trackpad assembly is screwed into the aluminum uppercase by screws no adhesive . Review MacBook Pro 16" 2021 Trackpad Replacement Step 17


I can see the screwsockets but i did not mean the aliminum unibody side...

I am asking for the side between sensor layer and metal strip/band, in other words the opposite side you explained @danj


@emh06 - Lets get to the reason you have such concerns.

Trying to figure out how many fleas can fit on the tip of your finger doesn't make much sense. Deconstructing a parts construction is also pointless.

So why are we going through this exercise?


Add a comment

Add your answer

emraha06 will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 68