lasers

We're happy to interview Coherent, as part of our series of interviews with MicroLED Industry Association members. Coherent is one of the world's leading laser innovators and manufacturers, providing systems and components for the production of OLED and microLED displays.

Q: Can you introduce your company and technology?

Oliver Haupt, Director, Marketing, Display Vertical, Coherent Corp: For over 50 years, we have been providing high-performing, reliable photonics-based solutions that have become the enabling tool in many applications. Today, Coherent Corp. is one of the world’s leading photonics innovators and manufacturers.

Displays are getting larger and more interactive in our homes and cars. State-of-the-art displays are slim, bendable, and high-resolution, with a wide color gamut. Future displays will range in size from tiny ones for AR/VR applications, to more than 100-inch in diagonal for very large wall TVs.

Germany-based 3D-Micromac is the industry leader in laser micromachining and roll-to-roll laser systems. The company develops and manufactures processes and laser systems delivering powerful, user-friendly and leading-edge processes with superior production efficiency. 3D-Micromac offers industrial laser solutions for the mass production of microLED displays.

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We had the pleasure of talking to Frank Richter, Head of Sales and Product Management at 3D-Micromac. Frank explained 3D-Micromac's solutions and technologies for microLED production, and the company's views on the future of microLEDs.

Q: Can you detail 3D-Micromac's solutions for the MicroLED market?

Frank Richter, Head of Sales and Product Management: 3D-Micromac’s product portfolio includes several laser-based system solutions for various manufacturing steps in the MicroLED production process. All systems offer an integrated process control and monitoring to assure stable and reliable operation thus enabling high throughput and low yield losses.

3D-Micromac announced that a leading optical solutions provider has purchased several microMIRA laser lift-off (LLO) systems to use in the production of microLED devices. The systems will be installed in pilot lines and production lines at its state-of-the-art LED chip factory in Asia

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3D-Micromac says that the microMIRA laser system provides highly uniform, force-free lift-off of different layers on large-area substrates at high processing speeds without the need for costly and polluting wet chemical processes. The unique line beam system is built on a highly customizable platform that can incorporate different laser sources, wavelengths and beam paths to meet each customer's unique requirements. The system is capable of processing different substrate materials and sizes, and can achieve processing speeds (including handling) of up to 60 eight-inch wafers per hour.

In the next two weeks, Toray Research Center (TRC) is hosting online webinars focused on display technologies. TRC, who supplies technical analysis and support for R&D and manufacturing, invites you to attend the online lectures at no cost, to learn more about microLED, OLED and QD technologies.

The webinars include recorded presentations, which will be available online up until to November 22. You can register for the webinars here.

This is an article by TechBlick, organizers of the upcoming MicroLED Displays virtual event. MicroLED-Info readers get a 100 Euro discount.

In this article, using select technology slides, we highlight several interesting advancements in MicroLED and/or QD displays. More specifically, we cover 3600PPI “Silicon” Displays | Gravure printed microbumps | Electrohydrodynamically printed QD color converters | Laser LLO and Transfer for MicroLEDs | QD vs Phosphors | Energy saving credentials of microLED

“Silicon” Displays with an incredible 3600ppi full color using microLED and QD technology?

Sharp (HIRANO Yasuakie et al) has developed this technology.

As shown in the slide below, first blue-only uLEDs are formed on a sapphire substrate. Here, one LED array contains 352 x 198 micro LED dies of 24 um x 8 um in size. In parallel, an LSI chip containing the driving circuitry is formed on a silicon wafer. Here, the cathode (N-type electrode) and anode (P-type electrode) are fabricated for each micro LED die to apply driving voltage independently to each die. The Au bump electrodes are fabricated in accordance with the pitch of the LED dies. The two substrates are flip-chip bonded using Au-Au bonding. Here one can already see the parallel to the silicon and optoelectronic industry (vs. the traditional thin film display industry!). Next, the sapphire layer is removed via laser lift off. Finally, Cd-free quantum dots (green and red) are deposited atop the microLED dies to enable R G color conversion. This way one achieves RGB colors.

Kulicke and Soffa Industries (K&S) announced that it has received two purchase orders, from two separate customers, for its LUMINEX, a disruptive laser-based mini and micro LED die-transfer solution.

K&S says that its highly flexible system is capable of single die transfer, multi-die transfer and mass transfer, supporting sorting, mixing, re-pitching and placement process steps. The broad flexibility of this system addresses the growing advanced display value chain and supports needs of LED, OSAT, panel and display suppliers.

Taiwan-based laser micromachining subsystem and equipment manufacturer Bolite Optoelectronics announced its new automated side-wiring system, the laser-based Bolite SW-L, which can be used for the production of tiled microLED displays.

This laser-based tool offers high-precision alignment, advanced process control, and full automation with robotic handling. The minimum line with and spacing is 5 um. Bolite says that this system is highly compatible with TFT production processes. The SW-L systems are now available, and Bolite is already accepting orders.

This is a sponsored post by Coherent

Coherent is a leading global supplier of lasers and photonics technology. For the MicroLED industry, Coherent provides several solutions from a single laser source, optical systems up to an integrated system for the three vital processes in MicroLED fabrication – Laser Lift-Off (LLO), Laser-Induced Forward Transfer (LIFT), and Repair/Trimming.

Coherent recently published a new white paper that provides an update on how high-energy ultraviolet laser beams enable LLO and LIFT processes. The white paper shows the importance of a perfect combination of laser and optical design to a how these lasers ensure placement accuracy and mass transfer that will remain future-proof as microLED chip die size continues to shrink.

The founder and General Manager of Bolite Optoelectronics, Dr. Bowen Cheng, was invited to present at the recent Touch Taiwan 2021 Conference in April. The title of his talk was “Laser Processing Applications for the Manufacturing of Mini and MicroLED Displays.” Since it was presented in Mandarin only, microled-info.com caught up with Dr. Cheng to learn more about this trending subject and the company he started.

Q: Dr. Cheng, can you please tell us a little about your background, prior to starting Bolite?

I was a research engineer at Xerox PARC and helped develop surface micromachined microspring interconnects in a project funded by the U.S. Army Research in collaboration with Oracle. I was also a vital member of the team that successfully demonstrated the world's shortest wavelength diode laser at the time, a 250 nm UV laser for military applications. With these experiences in both semiconductor laser processing and MEMS processing, I decided to start Bolite and build a team to develop state-of-the-art laser solutions for microprocessing applications.

Q: I must admit I’ve not heard of Bolite before. What differentiates you from other laser microprocessing companies?

3D-Micromac announced a new microLED mass transfer tool, called microCETI. The company says its new technology can be used to transfer over 130 million microLEDs per hour.

MicroCETI is based on a laser-induced forward transfer (LIFT) process that can support almost any microLED material and shape. The tool also includes optional modules - a laser lift-off (LLO) module, and a single LED die repair module.