iPhone 4 Screens Break 82% More Than 3GS

A surprising number of readers have submitted linkage to a story discussing a recently released study that proclaims that iPhone 4 glass breaks way more often than the 3GS's. Although the chart that I found more surprising was the one that said almost 9% of iPhone 3GS screens crack after a year.

Comments

Re:9% after a year?

[BasilBrush]

9% annual accident rate implies one accident requiring an insurance claim in 11 years. Doesn't sound particularly high for an item that is so easily dropped.

(Actually CmdrTaco can't read charts. That chart is nearly 8%, not nearly 9%. Which implies 13 years between claims.)

Re:Interesting properties of "Gorilla Glass"

[Facegarden]

Glass is really remarkably strong when it comes out of the furnace. The tensile strength is amazing, it can bend enough to absorb some shocks. It's a great material before it gets to the real world.

But, once it does, it immediately develops microcracks in the surface, and each of these could be the beginning of a fracture that goes through the bulk of the glass. So, what to do?

I don't know if they've taken the hint from the semiconductor industry (look up 'strained silicon') but they did a similar thing with glass. By bombarding the surface of the glass with larger atoms, they create significant stress in the surface, so that any microcracks are immediately pushed shut. But, this is only true down to the level that these atoms diffuse into the surface...not far at all!

So, if you create a significant scratch (and this might just be 100 microns) you are through this surface, and have a potentially catastrophic failure waiting to happen.

A screen-protecting film of plastic would be a good investment.

I worked at a glass shop for a summer installing windows and doors in peoples houses when I was younger. If it wasn't a brand new house, we'd have to take out the old windows. Often those windows had tempered glass. We took all the old windows back to our shop and threw them in a big trailer for the dump (sadly, window glass isn't as high quality as bottle glass, so it wasn't worth recycling. or thats what they told me).

Anyway, we loved to break the tempered glass. Normal glass breaks in big sheets, but tempered glass is made for safety, so it is both stronger, and won't break into sheets - it shatters into 1000's of tiny pieces when it breaks, so you can't get stabbed.

The fun comes with how it breaks. You can hit a 1/4" thick tempered glass window head on with a sledge hammer and it won't break. BUT, tempered glass gets its strength from really high surface tension, which is unbalanced on the edge of the glass. So, after we hit the thing with the sledgehammer and it didn't break, we'd take a regular hammer and lightly tap an exposed edge of the glass, and BOOM, it instantly shattered!

I don't know how gorilla glass compares to regular tempered glass, but it seems like a bit of a bad design to have the edges exposed like that.

But then, we knew it was a bad design...
-Taylor