We have recently noticed a rather insidious pattern occurring with the iPhone 6 Plus’s being brought in to us. It began with a customer bringing in their iPhone 6 plus for which we had done a screen replacement for some time ago. The phone was showing the occasional occurrence of grey bars flicker on the screen and then becoming unresponsive unless the phone was bent in a particular manner. We Initially believed that it was an issue with the screen itself and although it was outside the warranty period for the repair we decided to do the screen for him anyway he was a good customer. We eventually determined that the screen was fine and that the issue was a problem with the logic board. Since then we have seen several iPhone 6 plus’s all showing exactly the same issue. Intrigued we began to do some research on the issue and have been quite shocked by what we found.
Essentially the problem is with the iPhone 6 and 6 Plus touch IC’s on the logic board, the touch IC’s are the integrated controllers which detect touch on the screen thereby allowing us to use touch as an input for our smart phones and other devices. On a modern flagship smartphone logic board the components are attached using ball grid arrays (BGA) which are very efficient in fitting lots of components on the board but which sacrifice durability compared with other methods of soldering the components. Despite the lower durability this wasn’t an issue in the iPhone 5 or 5c which used underfill, a tar like substance that supports the BGA or even in the iPhone 5s which didn’t use underfill, so why would the iPhone 6 and 6 Plus be different?
Well one of the biggest differences between 5th and 6th generation iPhones is the housing. The 6th generation saw a large increase in screen size as well as a much thinner housing. The consequences of these changes were that the iPhone 6 and 6 Plus are bendable in a way that previous iPhones (and most other phones) were not, an issue which initially caused quite a lot of media attention and which resulted in the iPhone 6s frame being quite a lot stronger that its predecessor. The long term legacy of this bendability is that over time the bending and flexing put pressure on the BGA’s connecting the touch IC’s to the logic board causing them to crack and eventually (either from being dropped or just after pressure is applied over time) separating them from the board. With the right combination of pressing and twisting the chips and the board can be pressed back together, temporarily restoring function to the device but eventually oxidation kills off this solution and touch function is lost completely.
We should note that this not currently considered an issue by apple, even though a quick google search reveals numerous videos and posts complaining about the issue! If your iPhone is under warranty they will replace it of course but otherwise, they will simply offer to sell you a refurbished unit. With the increased durability of the 6s and 6s Plus housing this is an issue we probably wont see repeated in that generation but that will be cold comfort for iPhone 6 and 6 Plus users who have lost a phone due to this issue.