Sony’s CrystalLED and Alien Technology

By Bob Raikes

While going around ISE earlier this year and looking at the latest innovations, I got to thinking about the Sony inorganic LED TV shown at CES (but not at ISE). For those that missed the news, Sony showed a very good looking 55″ TV set based on inorganic LEDs (rather than OLEDs) and reports since the show have suggested that the display was made by wiring together individual R, G, B LEDs. The set, called ‘CrystalLED’, was highlighted as a technology demonstration.

I had a think about the panel at ISE as we were talking to a number of suppliers of the large inorganic LED displays and they have always told me that the cost of these displays is proportional to the number of LEDs, so the cost goes up dramatically as the pitch gets smaller. That got me thinking about the costs of the Sony display. Let’s assume that the great performance would allow Sony to sell the 55″ set at a premium and at a panel price of, say, $600 – a significant premium on the current price for 55″ LCD panels.

However, when you count the number of LED devices, you find that you need six million individual devices, although they might be encapsulated in trios (so two million trios). At $600 for the panel, that would mean that you need to make the LEDs at 0.01 cents each (not allowing for any assembly cost!). That’s 10,000 devices for a dollar. Given that we will have a report in next week’s issue on companies that can make new ‘low cost’ LEDs on silicon substrates at 17,000 per $500 wafer (or thereabouts) you can see that we are a very, very long way from anything that is likely to be feasible in any reasonable time.

I’m reminded of the technology from Alien Technology that we reported on for a couple of years from 1999. We were excited by the idea that Alien Technology had of ‘fluidic self assembly’ (FSA). The company found that silicon wafers could be etched into huge numbers of tiny chips which could have an accurate geometry. The company took these chips, put them into a fluid, then flowed them over a substrate where they dropped into holes in the substrate. The idea was to avoid having to make transistors directly on the LCD glass, but instead make them in silicon foundries, where the process was well understood, and drop them into pretty well any substrate (flexible etc). The firm generated huge ‘buzz’ at the SID for a couple of years.

I was very interested in this until I was talking to an old friend, Chuck McLaughlin, who pointed out that he had done some simple maths – he calculated how many chips the firm could get from a wafer and divided the cost of the wafer by the number and realised that the technology could never be competitive in display applications. That was the end of Alien as a display company (although it became an RFID company and survived – though there is no mention of FSA on its website).

So, for the Sony LED display to be cost effective, Sony would have to make not 17,000 devices per 150mm wafer, but 5,000,000, assuming LCDs don’t get cheaper and OLEDs can’t be cheaper still. Don’t hold your breath!