Frequently Asked Questions About Sapphire for Consumer Electronics

Q: How can sapphire compete with glass?

A: By leveraging sapphire's performance advantages and recent advances in sapphire manufacturing to enable new functions and to differentiate new products.

  • Sapphire's Primary Performance Advantages*:
    • Sapphire is stronger and more scratch-resistant than glass and is therefore more durable than glass in real-word conditions.
      • It's easy to find glass company videos and photos on the internet demonstrating glass samples bending in extreme directions without breaking.  Yet, virtually every user of a mobile device has experienced a broken glass screen at one time or another.  How can this be?  It's because those "bending glass" demonstrations are typically performed in a laboratory with pristine glass surfaces.   Pristine glass surfaces are interesting in the lab but aren't realistic in everyday life.  As soon as a glass surface gets scratched, it's much more likely to suffer a catastrophic failure from stress concentration effects, as many users have experienced.  Unfortunately for glass, there are many common items that can cause scratches, particularly sand, asphalt and concrete.  Scratches from these materials are often among the primary root causes of glass screen failures.
      • Since sapphire is harder than sand, asphalt and concrete, sapphire will typically avoid scratches from these common materials and the resulting problems they can cause.
      • Also, sapphire manufacturing techniques have improved dramatically in the past 2-3 years, resulting in significant improvements in sapphire strength and consistency.  Rumors of sapphire being weaker than glass typically originated prior to the maturation of modern sapphire fabrication methods & equipment, and without consideration of real world fracture toughness conditions.  Certainly, poor manufacturing methods can result in poor quality materials in any industry -- whether the material is glass, steel, titanium or sapphire, which is why sapphire suppliers must be chosen carefully.  Properly fabricated sapphire will always be more durable than glass in real world scratch and fracture toughness tests with sand, asphalt and concrete.
    • Sapphire has much better thermal management properties than glass.
      • Sapphire transmits approximately 40 times more heat than glass.  Sapphire's higher thermal transmission means sapphire-covered devices will typically run cooler, and cooler operating temperatures can result in longer battery lives and faster processing speeds.
    • *Note: Sapphire has multiple performance advantages over glass, as listed on the Sapphire Performance Advantages web page of this site.  For the purposes of this FAQ, however, only the durability and thermal management advantages of sapphire were highlighted.
  • Advanced Manufacturing Creates Attractive Economics for Sapphire Customers:
    • Sapphire's costs have decreased dramatically in the past 2-3 years as production volumes and yields increased and costs were driven out of each step of the sapphire supply chain.  Sapphire industry leaders are also ready to scale up their production capacities as sapphire is adopted in high-volume applications worldwide.
    • Sapphire is a premium material, with premium performance that can often command a price premium over products with glass components.  Glass is cheaper than sapphire, but recall that plastic is cheaper than glass; yet, the mobile phone industry moved from plastic screens to glass screens a few years ago despite the fact that glass was more expensive than plastic.  Sapphire's recently reduced costs and increased production volumes could enable a similar dynamic versus glass.
  • Sapphire Enables Product Differentiation & Enhanced Brand-Building:
    • Sapphire has an inherent marketing allure that conveys premium quality & performance -- key assets for product differentiation and brand development.
    • Sapphire is not for every company, not for every product and not for every customer.  But, for companies and customers that value premium performance and product differentiation, sapphire is a compelling choice.

Q: What's the status of Consumer Electronics device makers' view of sapphire as material for mobile devices?

A: Of course it's difficult to say with certainty which materials are on device makers' product road maps, but There are indications that consumer electronics device makers continue to work on sapphire applications.

  • In particular, one of the largest cover glass makers in the mobile device industry publicly-disclosed in 2016 that it acquired sapphire production equipment with estimated annual capacity of tens of millions of device unit display covers.
  • For the past several years, leading consumer electronics device makers have been using sapphire for camera covers, fingerprint sensors, & watch crystals.  Many product companies are familiar with sapphire and its performance advantages.
  • There are some in the consumer electronics industry who believe device makers continue to include sapphire on their respective product road maps, but definitive information on product development plans and road maps is not currently available.

Q: What about the tempered glass screen protectors on the market as mobile device accessories that claim hardness of 9H?  Isn't that the same hardness as sapphire?

A: No, it's not.  "9H" hardness is not the same as sapphire's Mohs hardness of 9.  Sapphire is actually 3-5x harder than "9H" glass (depending on the testing method).

  • "9H" is a measure of what's known as "pencil hardness," which uses a rating scale from 4B to 9H to measure the durability of coatings and films.
  • The Mohs hardness scale is a relative measure of material hardness and is commonly used in material science analysis.  Sapphire has a Mohs hardness of 9 (only diamond is above sapphire on the Mohs scale, at a Mohs hardness of 10), while tempered glass and ion-strengthened glass typically have a Mohs hardness of approximately 6 or less.
  • Note that the Mohs scale of 1 to 10 is a relative scale, not a linear scale.  A more quantitative way to evaluate material hardness is to use a Knoop or Vickers material hardness measure.  By Knoop and Vickers hardness tests, sapphire is approximately 3-5 times harder than "9H glass" (depending on the testing method).