iPhone X teardown - that's dense - Page 1
Forum section: electronics / general

author: chicken
author_rank: Frequent Contributor
timestamp: November 03, 2017, 02:59:58 pm
content: The innards of the new iPhone X are a marvel of density.https://www.ifixit.com/Teardown/iPhone+X+Teardown/98975Reminiscent of package-on-package stacking commonly seen for CPU/memory, Apple stacked two circuit boards. From the looks of it, they used a third PCB with solder balls as interconnect... but don't fret, Molex, Hirose et al still got their fair share of the BOM

author: chicken
author_rank: Frequent Contributor
timestamp: November 03, 2017, 03:31:04 pm
content: A better view of the stacked / sandwiched circuit boardshttps://www.ifixit.com/Teardown/iPhone+X+Teardown/98975#s182913

author: Tomorokoshi
author_rank: Super Contributor
timestamp: November 03, 2017, 04:21:46 pm
content: I can't tell if there is some springiness or compliancy with the spacer board. How will they guarantee connection across temperature and vibration?

author: grumpydoc
author_rank: Super Contributor
timestamp: November 03, 2017, 04:25:35 pm
content: Quote from: Tomorokoshi on November 03, 2017, 04:21:46 pmYou need to hold it the right way..............

author: bd139
author_rank: Super Contributor
timestamp: November 03, 2017, 05:38:12 pm
content: That's quite impressive. I get angry when I have to route one layer with three through hole components on itEdit: I have seen boards stuck together like this before, in a guidance system.

author: SeanB
author_rank: Super Contributor
timestamp: November 03, 2017, 05:56:54 pm
content: Only has to last till the next model comes out..........

author: SeanB
author_rank: Super Contributor
timestamp: November 03, 2017, 05:58:37 pm
content: Quote from: bd139 on November 03, 2017, 05:38:12 pm28 layers of flexible PCB per connector, with a bend in the middle. Not fun to change a connector there.

author: bd139
author_rank: Super Contributor
timestamp: November 03, 2017, 06:24:43 pm
content: Take it in the Apple store, pay the insurance premium, walk away with new handset, shrug

author: tooki
author_rank: Super Contributor
timestamp: November 03, 2017, 07:01:14 pm
content: Quote from: Tomorokoshi on November 03, 2017, 04:21:46 pmThat was my first thought, too. But given the vibration and environmental testing they subject them to during development, they must have achieved reliability at least as good as what prior models offer.

author: Monkeh
author_rank: Super Contributor
timestamp: November 03, 2017, 07:06:01 pm
content: Quote from: tooki on November 03, 2017, 07:01:14 pmSo regular failure of the touchscreen is still to be expected, then?That is an impressively packed pair of boards. Had to be fun to lay those out..

author: bd139
author_rank: Super Contributor
timestamp: November 03, 2017, 08:57:57 pm
content: We’ve got about 200 iPhone 6s/7 handsets. Pretty reliable. People smash them and that’s about it. But the same people smash anything we give them.Was great as we got to keep all the boxes and they go for £20 a pop on eBay. Quick £100 for me that was.

author: odessa
author_rank: Regular Contributor
timestamp: November 03, 2017, 09:10:58 pm
content: Quote from: grumpydoc on November 03, 2017, 04:25:35 pm

author: tooki
author_rank: Super Contributor
timestamp: November 03, 2017, 09:30:10 pm
content: Quote from: bd139 on November 03, 2017, 08:57:57 pmPeople buy the empty boxes?!? Who needs that?Oh wait, I think I just answered that myself: thieves who are selling stolen phones.

author: thm_w
author_rank: Super Contributor
timestamp: November 03, 2017, 10:05:39 pm
content: Quote from: Tomorokoshi on November 03, 2017, 04:21:46 pmIts soldered together, there won't a problem unless it breaks:Quote

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 03, 2017, 10:22:25 pm
content: Quote from: tooki on November 03, 2017, 09:30:10 pmThat's a rather pessimistic view. Sure, some folks will be up to no good, but there will be plenty who just want the Apple experience on the cheap.

author: chicken
author_rank: Frequent Contributor
timestamp: November 03, 2017, 10:48:33 pm
content: Quote from: Monkeh on November 03, 2017, 07:06:01 pmOn that subject, there was a funny observation on Twitter:https://twitter.com/smt2ios/status/926522039757824000

author: m98
author_rank: Frequent Contributor
timestamp: November 03, 2017, 11:47:09 pm
content: Already noticed that bypass cap(?) cutout. How do you achieve something like that? Are the dies laser-cut?

author: wraper
author_rank: Unknown
timestamp: November 04, 2017, 12:06:45 am
content: Quote from: m98 on November 03, 2017, 11:47:09 pmThis is not just an IC, it's a module containing other components, not just a silicon die inside.

author: m98
author_rank: Frequent Contributor
timestamp: November 04, 2017, 01:36:32 am
content: Quote from: wraper on November 04, 2017, 12:06:45 amThis actually made me research the packaging technology of such components a bit. Really interesting stuff. So while they seem to normally use wafer-level packaging, where all the individual ICs are together on the same wafer and are then cut out together in one piece, there are also embedded wafer level ball grid arrays, where individual dies are already cut out, then get pieced together with some kind of silicon molding compound and contacted with thin-film coating, like the WLPs. Seems like the latter option would allow the flexibility to add such a cutout without having to actuall respin the photomask and everything.

author: Richard Crowley
author_rank: Super Contributor
timestamp: November 04, 2017, 01:43:18 am
content: Well, Louis Rossman said that he didn't intend to be in the Apple repair business forever. Perhaps the end is near for repairable Apple products.

author: bd139
author_rank: Super Contributor
timestamp: November 04, 2017, 09:31:43 am
content: Quote from: Mr. Scram on November 03, 2017, 10:22:25 pmThey are usually bought by people selling their contract phones on. If you spend £20 on a box it adds £50 to the price of your phone when you sell it.

author: Kilo Tango
author_rank: Regular Contributor
timestamp: November 04, 2017, 10:14:18 am
content: The one thing about thiscrapsorry modern technology is that it keeps pushing the boundaries forward and in a way brings everything else along with it. What was the exception soon becomes the norm. Remember when we had portable valve radios, with 90V batteries ?. Usable time measured in 10's of minutes. Then the transistor came along and progress jumped up a notch, then the IC, then......Apple and Nasa have both in their own way moved technology & life forward.Ken

author: bd139
author_rank: Super Contributor
timestamp: November 04, 2017, 12:26:47 pm
content: Agree entirely.Society has been changed by the smartphone, some good some bad. Prior to Apple's attempts, we were stuck with Windows CE devices as the pinnacle of innovation. And they sucked (I worked as a software engineer on a deployment of about 10,000 of the damn things).

author: Jeroen3
author_rank: Super Contributor
timestamp: November 04, 2017, 02:51:51 pm
content: Quote from: Kilo Tango on November 04, 2017, 10:14:18 amPrecisely. Apple has paid manufacturers to learn to make this board stacking mass producible. When the contracts with Apple end, this knowledge is freed.Essentially making it affordable for the competitors the next iteration.

author: Ampera
author_rank: Super Contributor
timestamp: November 04, 2017, 04:30:53 pm
content: All this efficiency and technology, and you still are paying over a thousand dollars for a computer on which you can't do whatever you want, or install whatever programs you want.Also the notch in the screen is just stupid. They probably paid way too much for that very custom screen just so they could do that gimmick.

author: bd139
author_rank: Super Contributor
timestamp: November 04, 2017, 08:53:56 pm
content: As a part time sysadmin, software engineer and computer shit shoveler, I think this is a good thing. Most users can't be trusted with a computer, barely even rational thinking so I'm good with that. If you give the users the key to the computer, stuff like this turns up on your desk:For those willing to jump through a few hoops, and I'm not even talking about jailbreaking, you can run your own programs on them fine.Yeah it's a gimmick. A pretty cool one though. I'll probably skip it and buy an 8s when they come out instead.Incidentally I just fixed a failed AWS instance entirely on my 6s while having a shit. That's power

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 04, 2017, 10:27:41 pm
content: Quote from: bd139 on November 04, 2017, 12:26:47 pmSharp Zaurus predates both Android and iOS by many years. That's full on desktop Linux on a pocket computer.

author: grumpydoc
author_rank: Super Contributor
timestamp: November 04, 2017, 10:33:48 pm
content: Quote from: NiHaoMike on November 04, 2017, 10:27:41 pmIt was a nice bit of kit. Unfortunately it went the way of all PDAs, given that it did not have a camera and was not a phone.I think I might even still have mine somewhere around.....

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 04, 2017, 10:40:31 pm
content: Quote from: bd139 on November 04, 2017, 09:31:43 amI suspected as much, but don't know anything about Apple second hand prices, so a quick look on eBay wouldn't do. Thanks for the insight.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 04, 2017, 11:56:19 pm
content: Quote from: grumpydoc on November 04, 2017, 10:33:48 pmYou can still buy PDAs that are not phones. They just happen to be called "tablets". If you want something similar in size to the PDAs of back then, Apple even sells "iPhone without phone" that they call "iPod Touch". As for Android, just buy a cheap phone and not use the phone function like what the coiners do.If you long for the days of PDAs that had physical keyboards and ran desktop Linux, they still exist:Too bad it only has a not very impressive Atom CPU. I wish there was one with a Tegra X2! Would make for a very nice portable VR platform. And of course there should be an option to dock it into a laptop case for when you want a full size screen/keyboard.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 05, 2017, 12:05:55 am
content: The combination of Ubuntu and underboob is somewhat peculiar. Better than moobs, I guess.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 05, 2017, 12:32:42 am
content: All that exposed surface area doesn't just look cool, it actually does help with cooling. Keep in mind that her average thermal dissipation is about as much as that of a GTX 970 GPU. (Despite how skinny she is, she eats a lot. And thermodynamics says that the energy must go somewhere!)Back on topic, I once worked at a company that made smartphones and heard that one of their high end phones was having thermal issues under load. Thermal issues, on an aluminum back phone. Turns out the plastic case (one of the stock accessories) was impeding thermal dissipation. I don't think they had a real fix but everyone who saw the issue knew the workaround - remove the case.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 05, 2017, 12:54:17 am
content: How are these stacked boards interconnected? Or isn't that via stitching, but are those the actual interconnects?

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 05, 2017, 01:06:08 am
content: Quote from: Mr. Scram on November 05, 2017, 12:54:17 amThey're soldered together. And on the topic of thermal dissipation, I wonder how they're cooling the CPU that is on the inside of the sandwich.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 05, 2017, 01:30:47 am
content: Quote from: NiHaoMike on November 05, 2017, 01:06:08 amYes, they're soldered together, but I wasn't quite sure those are also the data connections. According to iFixit, they are. I guess the heat transfer happens through the PCB.Looking at the technology, it's a pretty crafty design. If you like technology, you must get a kick out of this.

author: amyk
author_rank: Super Contributor
timestamp: November 05, 2017, 04:14:15 am
content: Quote from: NiHaoMike on November 05, 2017, 01:06:08 amIt's designed to keep the CPU at "optimal" temperature, which means it fails just outside of warranty.

author: SeanB
author_rank: Super Contributor
timestamp: November 05, 2017, 05:50:39 am
content: They cool it by conduction, and by using throttling to keep the CPU temperature below the melting point of the solder.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 05, 2017, 06:03:18 am
content: Quote from: SeanB on November 05, 2017, 05:50:39 amWithout any bashing, Apple tends to use throttling as a technique to keep temperatures at bay. There are a few iMac models that do in fact have a fairly beefy Core i7. However, due to the construction and cooling solution, it can only be run at full blast for typically around 30 seconds before the thing starts to throttle itself back. Even though what's on the sticker is no lie, it also not very useful.