At SID Display Week, X-Celeprint has been showing, behind closed doors, a technology demonstration of its 5.1-inch microLED Display. This is the largest microLED display using a micro transfer printing process of which I’m aware.
(On the show floor at Display Week, AUO showed an 8-inch microLED display but refused to say it was transfer printed. AUO says its display uses color conversion technology, so, presumably all of the microLEDs are blue and the red and green are created by quantum dots or phosphors.)
The X-Celelprint display has 70 RGB pixels per inch, active-matrix switching using micro-ICs (not TFTs), pixel-level compensation, subjectively very high contrast, and highly saturated colors including a very red red.
The 5.1-inch, 70ppi, micro transfper printed microLED display shown by X-Celeprint at SID Display Week. (Photo: Ken Werner)
X-Celelprint has accumulated an extensive IP portfolio on micro transfer printing, including the transfer of LED chips to make microLED displays and the transfer of microcircuits and other small objects. The backplane of the display is created by transfer printing of the micro-IC pixel switches. The company uses a proprietary polymer transfer printing head that is able to pick the LED chips and micro-ICs off the wafers on which they were fabricated thanks to a sacrificial technology that frees the active layers from the bulk wafer. The printing head then prints the LEDs on the substrate. It is possible to design a head such that it pics up every tenth, hundredth, or nth LED. Then, when the LEDs are printed on their new substrate, the pixel pitch can be appropriate for a direct-view display, such as the 5.1-inch shown by X-Celeprint.
X-Celeprint intends to spin off a new company devoted exclusively to displays within the next 12 months.
Although the display is being shown only behind closed doors this week, the doors will be opened frequently for investors, partners, analysts, and even (gasp!) journalists.
(Disclosure: The author is a member of an X-Celeprint advisory committee. He is paid for this service, but so modestly it is unlikely to bias his opinions.)
Ken Werner is Principal of Nutmeg Consultants, specializing in the display industry, manufacturing, technology, and applications, including mobile devices, automotive, and television. He consults for attorneys, investment analysts, and companies re-positioning themselves within the display industry or using displays in their products. He is the 2017 recipient of the Society for Information Display’s Lewis and Beatrice Winner Award. You can reach him at [email protected].
