production yields

Adhesive developer and MicroLED Association member DELO has conducted in-house feasibility studies, that shows that their directional conductive adhesives can be used to replace soldering in miniLED, and microLED displays. The bonding was found to be reliable with high yields.

DELO says that current microLED displays use solder materials to interconnect the LEDs to the display backplane. But as chip size gets smaller, isotopic conductive materials (like solder) is not reliable as it is difficult to avoid short circuits, and so production yields suffer.

Kulicke and Soffa (K&S) announced that it is extending its long-term collaboration with surface mounting technology expert TSMT, to further enhance K&S' mini-LED and micro-LED placement solutions and get it ready for mass-volume adoption.

K&S offers its LUMINEX laser-based transfer solution, and the company now updates that it is working, together with TSMT, to enhance the yield from 99.99% to 99.999%. 

The MicroLED Association published its first white paper (LED Cost Analysis for MicroLED Smartwatch Displays) in January 2023, and has published two more white papers since.

The association is happy to announce that there have been over 2,200 downloads for its three whitepapers. MicroLEDs are considered to be the next generation display technology, and display professionals are looking for information and analysis regarding the latest microLED developments and technologies.

The MicroLED Association is hosting an open webinar in which we will give a talk focused on microLED yields: explaining the problem and its implications, and discussing the various strategies and next-generation technologies by microLED association members that aim to overcome and mitigate the problem.

The webinar will take place on February 21st (Tuesday) at 16:00 CET. You can use the following link to register, at no cost.

The MicroLED Industry Association published today a new white paper, that is focused on MicroLED production yields. This whitepaper discusses microLED yields, the current status, challenges ahead and several strategies and technologies that should help to mitigate the yield problem. Together with the white paper, the association is also hosting an open webinar.

Yield is an important parameter for display makers, as low yields can drastically increase production costs per panel sold. In the microLED industry, yields are even more crucial and are still a major challenge. In addition, as microLED production involves several separate steps, the yield discussion is more complex compared to the situation in LCD or OLED production.

The white paper is published on the MicroLED Association's website, and is open to the public.

We're happy to interview Unikorn Semiconductor Corporation, as part of our series of interviews with MicroLED Industry Association members. Unikorn is a professional III-V compound semiconductor foundry that was spun-off from Epistar and now is a part of Ennostar. Unikorn focuses on epitaxy and wafer/chip processing.

Q: Can you introduce your company and technology?

Unikorn Semiconductor Corporation, a subsidiary of Ennostar Inc., is a professional compound semiconductor foundry located in Hsinchu Science Park, Taiwan, and focuses on epitaxy and wafer/chip processing by providing corresponding process parameters and production platforms that meet customers’ unique specifications and technology requirements. Not only does Unikorn offer customers our professional and quality manufacturing service on lead time, yield and customized designs, but it also ensures the protection of intellectual properties, process recipes, and structural designs of our customers with the strictest standards.

With the development of new technologies and applications, markets grow rapidly. Unikorn has the proven ability to provide comprehensive foundry services that meets these booming applications.

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.

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.

We're happy to interview ALLOS Semiconductors, as part of our new series of interviews with MicroLED Industry Association members. ALLOS Semiconductors is an IP licensing and technology company that focuses on GaN-on-Si technology for the microLED industry. ALLOS offers a turn-key technology transfer to establish a super-uniform CMOS-compatible large epiwafer process at customers within only 12 weeks.

Q: Hello! Can you introduce your company and technology?

ALLOS Semiconductors is the global leader for gallium nitride on silicon epiwafer technologies (GaN-on-Si) for next generation, micro LED-based display solutions and other applications building on more than 20 years track-record.

Our customer and partner base includes top-tier companies from the electronic device, display, LED and semiconductor foundry industries. They benefit from the cost, yield and performance advantages of our patent-protected 200 and 300 mm GaN-on-Si micro LED epiwafer technologies – including our unique 1 bin® technologies.

We're happy to interview eLux, as part of our new series of interviews with MicroLED Industry Association members. eLux was established in 2016 in the USA as a spin-out from Sharp Labs of America. eLux expertise and intellectual property development focus on the massively parallel assembly processes that enable low cost manufacturing of microLED displays.

Q: Hello! Can you introduce your company and technology?

eLux, Inc. was founded in 2016 as a spin-out from Sharp Laboratories of America. eLux's objective is to develop direct emission displays based on microLED technology targeting large format displays for video wall and television applications. Core personnel of eLux, including Jong-Jan Lee (President and CEO) and Paul Schuele (CTO), had extensive experience in display development working at Sharp Labs.

A 2X8 tiled microLED display made in collaboration with a large display company shown at Touch Taiwan 2022

The work done at company headquarters in Vancouver, Washington consists of development of fundamental microLED assembly technology and characterization of display performance and reliability. Direct emission display development involves extensive collaboration with microLED suppliers and manufacturers of display backplanes, so significant effort is involved in prototype fabrication, which takes place in Taiwan.

The microLED transfer process is crucial in MicroLED display production, this is likely to be the most challenging part of the entire process. In this article (an excerpt from The MicroLED Transfer Process Report), we'll give an overview of the transfer process, its challenges, and alternatives.

At the beginning of this stage, there's the wafer with the MicroLED chips, and a display substrate with the backplane TFTs on top. As we said, this is a challenging process, and there are three main challenges in this step – accuracy, speed and reliability.

It is important to note that if the display is based on RGB microLED devices, it complicates this step further – which is why many MicroLED makers are expected to adopt blue LEDs with color conversion.