Maybe the fourth time's the charm? This week Apple released a new crop of
MacBook Pros that they claim address the keyboard problems that have plagued
MacBook Pros since the introduction of the butterfly keyboard in 2015, with the
redesigned MacBook. While Apple has mostly solved the dust issue by
switching to a more repairable design that allows you to remove the individual
key caps. The latest computers still have issues from key strikes that don't
register, to double and triple key strikes. Apple has said that this updated
MacBook Pro does not have a redesigned butterfly keyboard but rather a changed
material in the keyboard mechanism. With an exceptionally vague statement like
that we decided to try to find out what changes Apple actually made, and for that
we needed to consult with some experts.
My name is Eric Beaton. I am the Lab Tech here for the Materials Engineering Department at Cal Poly.
So we deal with materials. We help determine what's going wrong with materials
we help improve materials know materials, we will do failure analysis, we deal with corrosion so when you're
designing something and you need to select a material for an application typically
it's a materials engineer that you're going to come to. This is our FTIR. This is used for identifying polymers. It uses an IR
light and it's basically shiny an IR light onto the surface of the polymer,
and the functional groups of the molecules that make up the polymer will
absorb that like in different amounts. Several layers make up the butterfly key
and we know one or more of them may have changed. Topping it off is the key cap,
and below that is the butterfly mechanism that controls the keys motion.
Below that we have the dome switch cover supporting a flexible membrane that
moves with the key and then we get to the main character of the assembly the metal
dome switch. One or more of these layers may have been altered and hopefully the
FTIR scans can tell us what's changed within the dome switch cover.
We've got the Switch housing for the 2018
butterfly keyboard. We figure we'll start with that... let's see if we do spotting differences
with the new version.
You see that the peaks here are vastly different. these plastics are
definately different. I am very confident now that they are different plastics.
Now we've got 2 different types of
plastic involved but we're going to need some more analysis and since we also
suspect that the metal dome switches have changed we're gonna need another
expert. My name is David Niebuhr, my focus is on metallurgy and failure analysis. So we
have the switch cover, the two switch covers and so from looking at
them under the microscope the first thing you can see is that polymers are
definitely different. Even if you didn't know that for a fact the Left called the
old polymer on the 2018 is more opaque the polymer on the right is less opaque
but it's it seems it is a little thicker if not more robust than the left, and
then after looking at the results that you obtained using FTIR, it identified or
it surmised, that the older one the 2018 is the polyester acetylene and the new
one is a nylon. It's a polyamide which is just a general term for nylon and it's a
polyamide six. It makes sense that they would go to a nylon if they were having
issues with the... the prior polymer if it was somehow not performing, ripping or
just failing in any way allowing... because it looks like it's meant to form some
kind of a barrier there to keep any kind of moisture out, and I know from
experience that nylon so are fairly robust as polymers go. From a structural
standpoint they have good mechanical strength as far as polymers go. And now
we can take a look at the metal dome switches. From looking at it the weak
point is probably at the tabs on the outside. Over time
these little tabs here will fatigue, because you can imagine is as its
push down, like that, and then it changes back back back back then likely there's
gonna be cracks forming at these outer lines here. What I would say is if you
wanted to compare the two just side by side again left being the 2018, the right
being the 2019, is that structurally they look identical. I don't see any
differences in either the process that were made or in the actual thickness of
the material or even the bending of the tabs on the end or the travel for that
matter. Looks like the travel is identical. I
would think that if they were to go to the trouble of making any kind of design
change in terms of the travel it would be something that you would be able to
see because these to me are identical in terms of their height. As I said earlier
I looked at the two materials they are identical in shape so perhaps they
thought well maybe the spring is fine and we just need to protect it better,
and instead of changing the spring itself they're just gonna try to protect
the spring. Or the other mode of thought would be well we're gonna protect it
also and we're also gonna change the material. So it could be a two-fold thing
and my gut is they're probably doing both because they're probably saying
that this is a big enough issue that we're gonna attack it from every
direction we can. If you were Apple what would you do? Would you keep chasing it? Or would you give
up entirely and try something less failure prone? That is a very hard question to ask an engineer.
Because as an engineer we could always make it better. But it takes time, tests
and as a company you don't want your customers doing your testing for you.
And it sounds like that's sort of whats going on with Apple. So I mean if I was an Apple engineer I'd be saying yeahgive us
more resources to fix this problem because this is a cool design.
If I was an Apple marketing I would be saying no we don't want our customers
having this issue anymore. let's go back to what we know works.
Don't fix what ain't broken.