---
title: "What is a Smartphone screen made of?"
description: "Chemically strengthened aluminosilicate glass over a touch layer and an OLED or LCD panel, with an oil-shedding coating on top. Every component, the material it uses"
url: https://atoneplace.net/made-of/smartphone-screen/
site: "At One Place"
---

# What is a Smartphone screen made of?

**What is a Smartphone screen made of?: Chemically strengthened aluminosilicate glass over a touch layer and an OLED or LCD panel, with an oil-shedding coating on top.**

Chemically strengthened glass resists cracking but not scratching, and the two are different properties: the ion exchange puts the surface in compression, which fights crack propagation, while hardness against a sharp point is set by the glass composition. Sand contains quartz, which is harder than the glass, which is why a beach day scratches a phone that survives being dropped. Sapphire covers are far harder but more brittle and much more expensive, so they are used on camera windows and watch faces rather than on phone screens. Repairing an OLED screen is expensive largely because the layers are fully laminated together, so a cracked cover glass usually means replacing the whole assembly.

## Component by component

*Every material is a choice, and the third column is the constraint that drove it.*

| Part | Material | Why that material |
| --- | --- | --- |
| cover glass | aluminosilicate glass, ion-exchanged in molten potassium salt | Swapping small sodium ions for larger potassium ones near the surface puts the outside in compression, so cracks cannot start easily. |
| oleophobic coating | a fluoropolymer layer a few nanometres thick | It makes fingerprints wipe off; it is also the first thing to wear away, which is why an older phone smears more. |
| touch sensor | a grid of indium tin oxide, or metal mesh, on glass or film | ITO is one of very few materials that is both transparent and conductive, which is what a capacitive touch grid requires. |
| display panel | OLED — organic emissive layers on a thin-film transistor backplane — or an LCD with a backlight | OLED pixels make their own light, so black is genuinely off, and the panel can be thin and flexible. |
| adhesive | optically clear adhesive bonding the layers | Any air gap reflects light at each surface; full lamination is why modern screens look like the image is on the glass. |

## Other electronics objects

- [Alkaline battery](https://atoneplace.net/made-of/alkaline-battery/) — Zinc powder and manganese dioxide either side of a potassium hydroxide paste, in a steel can.
- [Solar panel](https://atoneplace.net/made-of/solar-panel/) — Doped silicon wafers with silver contacts, sealed between low-iron glass and a plastic backsheet in an aluminium frame.
- [LED bulb](https://atoneplace.net/made-of/led-bulb/) — Blue LED chips under a yellow phosphor, plus a driver circuit and a heat sink — and it is the driver that dies.
- [Touchscreen](https://atoneplace.net/made-of/touchscreen/) — A grid of transparent electrodes measuring the tiny capacitance your finger adds — which is why gloves fail.
- [Computer keyboard](https://atoneplace.net/made-of/keyboard/) — ABS or PBT keycaps over either a silicone rubber dome on printed film, or individual mechanical switches.
- [Headphones](https://atoneplace.net/made-of/headphone/) — A neodymium magnet, a coil of copper wire and a thin plastic diaphragm — a loudspeaker shrunk to fit an ear.
- [Loudspeaker](https://atoneplace.net/made-of/speaker/) — A paper or plastic cone hung on a rubber surround, driven by a coil in a magnet gap.
- [Computer mouse](https://atoneplace.net/made-of/computer-mouse/) — An ABS shell around a tiny camera taking thousands of pictures a second, plus two clicky microswitches and PTFE feet.

## Common questions

### What is a Smartphone screen made of?

Chemically strengthened aluminosilicate glass over a touch layer and an OLED or LCD panel, with an oil-shedding coating on top.

### What is the cover glass of a Smartphone screen made of?

Aluminosilicate glass, ion-exchanged in molten potassium salt. Swapping small sodium ions for larger potassium ones near the surface puts the outside in compression, so cracks cannot start easily.

### What is the oleophobic coating of a Smartphone screen made of?

A fluoropolymer layer a few nanometres thick. It makes fingerprints wipe off; it is also the first thing to wear away, which is why an older phone smears more.

## Related pages

- [Alkaline battery](https://atoneplace.net/made-of/alkaline-battery/)
- [Solar panel](https://atoneplace.net/made-of/solar-panel/)
- [LED bulb](https://atoneplace.net/made-of/led-bulb/)
- [Touchscreen](https://atoneplace.net/made-of/touchscreen/)
- [Computer keyboard](https://atoneplace.net/made-of/keyboard/)
- [Headphones](https://atoneplace.net/made-of/headphone/)
- [Loudspeaker](https://atoneplace.net/made-of/speaker/)
- [Computer mouse](https://atoneplace.net/made-of/computer-mouse/)
- [Pencil](https://atoneplace.net/made-of/pencil/)
- [Tennis ball](https://atoneplace.net/made-of/tennis-ball/)
- [Banknote](https://atoneplace.net/made-of/banknote/)
- [Golf ball](https://atoneplace.net/made-of/golf-ball/)
- [Paper](https://atoneplace.net/made-of/paper/)
- [Glass](https://atoneplace.net/made-of/glass/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)