Apple’s Killer Sapphire Slicing Lasers

Posted: March 21, 2014 by mattmargolis24 in Apple Investor Information, GTAT Investor Information, My Publications
Tags: , , , , , , , , ,

Apple’s Killer Sapphire Slicing Lasers – by Matt Margolis

Nearly two month’s ago Apple’s sapphire window patent came to light and I know I focused my attention on the sapphire screen and thought to myself, “yup, they perfected the sapphire screen (window) no surprise.”  What I just realized today as did many others is that Apple might be using a laser to slice sapphire instead of the traditional diamond wire saws.  So what?  Laser cut sapphire screens would cost significantly less, the screens could be made faster and the yield per sapphire boule because of near elimination of kerf lost would also increase significantly.  It sounds like one of those “win win” situations.  The cost per screen would decrease dramatically since 50% of the cost of a completed sapphire screen (as of 2013) was split between the cost to grow the sapphire and the processing costs to transform a sapphire boule into a sapphire screen.  I know GT has improved the ASF furnace size as well as improved their boule quality through the use of their Intego Sirius Sapphire Display Testing Tool (image below).  Additionally, based on my discussion with a well-respected sapphire industry expert, Apple has been “squeezing” the raw material suppliers to reduce the material costs significantly.

Screenshot - 3_20_2014 , 11_03_32 PM

I think it’s important to to revisit the sapphire window patent and then introduce the new laser cutting technique since they are very closely related.  The sapphire window patent was developed, because glass is glass and sapphire is sapphire and “despite all the processing, the glass remains susceptible to damage and scratches, chips and cracks in the glass diminish the ability of the device to perform its intended purposes“.  I’m wondering why Corning doesn’t include that in their press releases and specs related to Gorilla Glass?  I mean, it is true right?  Below is the background issue related to current glass displays and the sapphire display summary.


[0002] Mobile electronic devices are ubiquitous in today’s society. From cell phones to tablet computers, they can be found in pockets, purses, and briefcases, and are used in both personal and business settings. Generally, the devices include a visual display output. In some cases, display may perform double-duty by providing the visual output and receiving touch input. Often, these devices also include cameras and other input devices. Both the display screens and camera covers are typically made of glass.

[0003] In processing the glass for use as a camera cover or a display screen, a large sheet of glass is initially cut into squares by a scribe and break process before each of the cut squares are ground into a desired shape. Chamfers may be added to the individual glass pieces and a chemical strengthening process may be performed to help fortify the glass pieces. Subsequently, each individual glass piece is lapped, polished and decorated to finally produce the glass cover or screen. The process is lengthy and includes many steps, most of which are performed on an individual basis rather than in a batch. Despite all the processing, the glass remains susceptible to damage and scratches, chips and cracks in the glass diminish the ability of the device to perform its intended purposes.


[0004] One embodiment may take the form of a method of manufacturing sapphire windows. The method includes obtaining a polished sapphire wafer and applying decoration to the sapphire wafer. The method also includes cutting the sapphire wafer into discrete windows. In some embodiments, the cutting step comprises laser ablation of the sapphire.

[0005] Another embodiment may take the form of a method of manufacturing sapphire windows that includes growing a sapphire boule, coring the sapphire boule to form a sapphire core and slicing the sapphire core into wafers. Additionally, the method includes lapping the sapphire wafers, polishing the sapphire wafers for provide polished sapphire wafers and dicing the sapphire wafer into discrete windows using a laser. The method also includes applying an ink mask to the discrete windows.

As you can see, one of the ways suggested ways to cut sapphire includes dicing the sapphire wafer into discrete windows using a laser.  This method would provide significant cost reductions and improve yield because kerf loss (think saw dust) would be substantially minimized.   The laser cutting technique could significantly lower the cost of sapphire screens and the potential premium that Apple would be paying for sapphire screens over reinforced glass.  I was thinking of Hyperion 4 but the power requirement below suggests a power of 50 watts, while Hyperion 4 uses 100 kilowatts which is equivalent to 100,000 watts.  This would be like me hitting my driver off the tee-box on a 132 yd par 3, just a little bit too much club for such a short yardage hole.   Maybe Apple is going to be using some Austin Powers’ laser beams to cut their sapphire screens or to make the iWatch screen?  According to Bloomberg Apple was going to spend $10.5B in 2014 on robots to lasers to shore up the supply chain.  Perhaps not as cool as Austin’s sharks with laser beams attached to their heads but Apple is definitely cutting edge.

The detailed description of the sapphire window patent is below:


[0023] Conventionally, sapphire has not been a viable alternative for glass or plastic surfaces of electronic devices. This is due in part to the cost of obtaining and difficulty of processing the sapphire. In particular, sapphire is relatively rare and expensive. Additionally, due to the hardness of the sapphire, conventional processes may not be effective or may result in faster wearing of tools and significantly increased processing times. Methods for creating sapphire windows are described herein that achieve processing efficiencies to, in part, make the replacement of glass or plastic members of electronic devices feasible, whereas previously such replacement would be at least cost prohibitive. Generally, the sapphire window may be C-plane sapphire, although other orientations may be implemented as well. The C-plane is typically more available commercially and provides a good level of hardness.

[0024] One embodiment may take the form of a method that includes cutting through the sapphire using a laser. That is, the laser may have sufficient power to cut through the sapphire. To this point, commercially available lasers have not been able to perform this task with sufficient efficiency, primarily due to insufficient power. Specifically, the laser may be capable of operating at or near 50 Watts, although some embodiments may utilize higher or lower power lasers. Additionally, in some embodiments, the laser power may be dynamically adjusted to suit a particular purpose. Moreover, the laser may operate in or near the IR band of the electromagnetic spectrum and may be capable of pulsing in or near the pico second time frame. In other embodiments, the laser may operate with pulse lengths from the millisecond to the femtosecond range. The use of the laser provides for a faster cut over conventional techniques, such as CNC grinding used for glass but that still yields a sufficiently clean edge. Further, the laser is able to cut with precision so that a single wafer of sapphire may yield more similar sized windows than a glass wafer that is cut using conventional techniques.

Apple’s new patent ‘Multi-Step Cutting Process‘ that emerged today.


[0004] Methods related to efficient processing of sapphire are discussed which are expected to both speed manufacture of corundum for applications and make the use of conundrum cost effective. In particular, one embodiment may take the form of a method of cutting a hard transparent material having a polished surface. The method includes roughening a portion of the polished surface, directing a laser beam on the roughened portion of the surface to melt and, thereby, cut through the hard material.

[0005] Another embodiment may take the form of a system for processing corundum including a roughening apparatus and a laser. The roughening apparatus initially receives a corundum member and roughens a polished surface of the corundum member. The laser then cuts through the corundum member by directing the laser at the portions of the polished surface that have been roughened.

[0006] Yet another embodiment may take the form of a method for cutting polished corundum including a surface preparation step and a cutting step. In the surface preparation step, a polished portion of the surface of the corundum is prepared for subsequent cutting through in-coupling of laser energy. In the cutting step, a laser is directed to the portion of the polished surface of the corundum that has been prepared.

Below are a few images from the patent.  One looks like a golf ball, or a cookie cutouts but it’s actually a very top surface of a boule or wafer that has had “holes” sliced from it.  The first thing I thought of is these little “cutout rings” would be perfect for the iWatch.   It’s still anyone’s guess exactly what is happening inside Mesa, but this new “killer laser” patent does shed some light on how Apple and GT Advanced Technologies never stop finding ways to reduce costs and make the sapphire screen process more efficient.  Deploying lasers to cut sapphire screens would significant  reduce the time consuming process of slicing them with diamond wire saw and it would significantly increase number of screens per sapphire boule.  The elimination of diamond wire saw cutting would increase the useable % of the sapphire boule, reduce costs, increase the amount of screens and allow Apple and GT to be more agile to respond relatively quickly to consumer behavior and trends.

Screenshot - 3_20_2014 , 10_43_23 PM Screenshot - 3_20_2014 , 10_44_46 PM

Full Disclosure: I am long GTAT  and have no plans to buy or sell in the next 72 hours



  1. ha65mph says:

      I Am   Tip  Toeing  thru  The Tulips  with you ”,  

    Been on this ‘GTAT’ because of MBand You…and reading  till my eyes  bled .

    Dang ,  I hate to be  Poor’…I  wish i could ”afford to buy more ”’

    Best Regards ”’… MUNGY






  2. Dick Evans says:

    Matt, from the bottom figure, does it make sense that they would use a diamond wire to slice the big, wide boule into thin sections, and then use the laser to cut out watch crystals and/or iphone screens from the thin slice as you discuss below. Or is that what you are saying? I am still wondering about the big diamond saw order that the German vendor supplied.

    Great find!



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