Chosen Solution
Hi there, Currently in the middle of doing an iPhone 7 small flex repair as it was ripped by someone. The pressure sensitivity doesn’t work but the rest of the functions of the home button work. I’m worried about the flux that i’m using affecting the sensor inside of the button itself as I’m working closely to it. I have covered some of the whole with thermal tape to hold the button and to keep the flux out but some has got in. Don’t want to find that when I finish the repair the home button doesn’t work because flux went in. Would appreciate the help on this one. Not sure if it will affect it.
If you are using a Rosin based flux (RMA or RA - unlikely as that is a dark flux) then you would definitely have to clean it off. If you are using a No Clean flux, then you shouldn’t have to worry about it. That said, it really depends on the flux. I am currently using the Chipquik 291 and I don’t like it at all. I find that it tends to crystallize and it can be hard to remove. You could try to put some IPA or better yet, real flux remover, that will dissolve most of it.
inside the home button where you are worrieing the flux might have damaged the home button is not right. There is Touch ID and flexcable including all those nano jumpers are covered with black underfill, and there is not any kind of button etc, And also Touch ID works it mean there isn’t any problem. check the Crystal ic near where you working called u10 or AD7149. If it’s cracked that’s the normally couse this issue. and if it’s not cracked the the connector on home button if it looks funny coz sometimes that needs replacing also, the best thing is that check all the pins resistance on the home button connecter with the multimeter on diod mode.
