iPhone Repair Demystified

by Sarah Ostheller

What are we going to do to your iPhone? Well, it depends on what is wrong. If the glass is broken but the display still functions normally,  we will replace the glass using a process called ‘refurbishing’. If the display doesn’t seem normal, we may have to replace it. In this case, we take an OEM screen and refurbish it with factory-new glass. Read on to learn more about the refurbishing process.

First, we need to remove the screen assembly. This means using a special, apple-proprietary screw driver to remove the small bottom screws near the charge port of your iPhone. Then, we either heat up or ablate the adhesive that glues the screen to the frame. The screen can then be strategically lifted from an angle and direction that won’t damage the flex cables (microscopic wires embedded in plastic) that connect the screen to your phone. Unscrew some shield plates and  disconnect the screen, and your screen is ready to start the refurbishing process.

Everything but the display and glass will need to go. There are a lot of parts on a screen assembly, and we will need to carefully remove them so they can be reattached to the new screen once it is finished. The display shield plate, the home button shield plate, the home button and flex cables, front facing camera, mic, and sensor flex cables, and front facing speaker will all be methodically and carefully removed and set aside.

The only thing left to remove now is the glass. Removing the glass from the display is no small task however. The glass is attached with an optically transparent adhesive (OTA) that is nearly impossible to manipulate at room temperature. We use a special machine that heats the phone up enough to soften the OTA without damaging the delicate electronics inside your phone. Then, a system of vacuums holds your screen in place while we carefully trim away the frame. This is delicate work, because if any point pressure is put on the display it will crack! The OTA can be cut by sliding a 0.1 mm molybdenum wire between the glass and the display, carefully shimming the wire up the full length of the display without scratching it. Once the OTA has been cut, the display can be lifted off the glass (which is still being held down with the vacuum!). Now that the display is free, we can begin to put on the new glass.!

Putting on new glass requires a clean slate. This means the old OTA needs to be carefully removed using a plastic razor and solvents like limonene and acetone. Once the screen is clean, we take it to a special workbench equipped with high power lights and fans to ensure no dust gets trapped between the glass and the display. A special frame holds the phone in place while we carefully place the new glass.

The glass can now be laminated to the screen. At this point, there is still a lot of air under the glass, so we move it to a machine specifically designed for this. Selecting the correct rubber cushion for your iPhone model, the screen is placed between two larger cushions in the machine (see image). The machine is turned on, the two metal trays are pressed together and the vacuum kicks on to a pressure of about -100 kPa. This is still insufficient to remove all the air from the screen however. Next, the screen will need to be heated to 90 C and placed in an autoclave at about 500 kPa (this is about 5x more pressure than we feel!).