Why phones break: Screens get stronger, yet we want more

An Apple iPhone is shown after a drop test from the DropBot, a robot used to measure the sustainability of a phone to dropping.

Ask a roomful of people to take out their phones, and you’re bound to see several with cracked screens.

Despite engineering breakthroughs, screen breakage has become a part of life, the leading type of phone damage.

In part, we’re to blame. We want phones that are bigger, yet thinner, offsetting strides made in strengthening glass. We also want phones to be sleek: A phone that’s rugged enough to withstand drops just won’t match what we expect smartphones to look and feel like.

“The tradeoff is phones get a lot bigger and bulkier,” said Rick Osterloh, president of Motorola. “Without a really big innovation and technological breakthrough, it’s going to be hard to (make a really tough phone) in a size people expect.”

That’s not to say phones aren’t getting stronger. In fact, given how frequently we use phones, juggling them as we commute, run errands and chase after children, it’s amazing screens don’t crack even more.

The latest phones from the two leading phonemakers — Apple’s iPhone 6s and 6s Plus, and Samsung’s Galaxy Note 5 and S6 Edge Plus — mix zinc into aluminum frames for aero- space-grade strength. The frames will absorb more of the shock that would have gone to the glass, and help prevent them from bending in pockets.

The displays also use ion-strengthened glass. Samsung uses Corning’s Gorilla Glass 4, which gets heated in a process that replaces sodium ions on the surface with potassium ions. Because potassium ions are larger, they press together to create a stronger surface. Apple turned to Corning for a custom glass with greater strength.

Even some budget and mid-range phones, including Motorola’s, are now using strengthened glass, though made with older, weaker formulas.

With strengthened glass, you can still pierce the armor with enough pressure, but it’s harder than with normal glass.

SquareTrade, which offers protection plans for consumer electronics, said that while phone screens used to crack after one or two drops, the latest iPhones and the Note 5 survived 10 drops each from six feet in tests. SquareTrade also said the new iPhone screens are more durable than last year’s models. (It didn’t test the Note 5’s predecessor for comparison.)

But for all three new phones, the screens broke right away when dropped face down on concrete.

Scott Forester of Gorilla Glass, said Corning has made strides in withstanding the types of surfaces most likely to puncture glass, including asphalt and concrete. But he said that’s offset by glass getting thinner and screens bigger over the years in response to consumer demand.

“It’s always this fine balance between practicality and design,” Forester said.

SquareTrade said half of its damage claims are for screen cracks. That doesn’t include cracked phones people hang onto because they don’t want to pay a $75 deductible.

Aware of consumers’ frustrations with breakage, HTC is offering one free replacement for any damage, including cracks, to its HTC One smartphone within the first year. Accidents are covered.

For other phones, we might simply have to get a case, insurance or both.

Can more be done? What about ditching glass for something stronger? Plastic is one candidate, but it’s prone to scratching.

Sapphire is a mineral that’s just short of diamond in hardness. It’s extremely scratch-resistant, but its resistance to cracking is up for debate. It’s also tough to manufacture, especially in larger sizes for phone screens. Apple uses sapphire for the smaller displays found on pricier Apple Watch models, as well as for the home button and camera lens cover on iPhones.