50‐3: Status of MicroLED Mass‐Transfer Processes and Equipment

Abstract

For MicroLED displays to be economically viable, microchip transfer and assembly technologies with micron‐scale accuracy, and throughputs at least 5 orders of magnitude higher than traditional pick‐and‐place and bonding equipment are required. This paper discusses existing and emerging technologies, from the lab to commercially available solution.

High‐performance MEMS shutter display with metal‐oxide thin‐film transistors and optimized MEMS element

“…MicroLED displays are still in their infancy, and their efficiency suffers significantly with dense pixels (smaller microLED pixels). 1 In addition, approximately 30%-40% of the power dissipation of current-driven OLED pixels comes from the backplane, and the problem is worse with microLED pixels due to their lower voltage requirements. 1 The MEMS shutter display has shown better performance in this respect and still has room for future improvement.…”

“…Several problems like mass transfer issues, suitable backplane, and manufacturing cost remain as a challenge for microLED displays. 1 Display technology is one of the main applications of large area electronics and MEMS technology has the promise to enable efficient, responsive, and vibrant image reproduction while reducing power consumption by eliminating lossy elements and increasing robustness. Though several attempts at commercialization had failed before, [2][3][4] our group has successfully demonstrated highly efficient and robust vertically translating MEMS shutter display for transmissive display application.…”

Advances in pixel driving technology for micro-LED displays

“…When handling lower gray levels, the LED will operate at a reduced current density. 60,61 Zhai et al 62 proposed using the PAM-PWM hybrid driving method, brightness can be precisely controlled by simultaneously adjusting the width and amplitude of the current pulse, thus avoiding the issues mentioned earlier. In this method, LEDs are preferentially excited during subframes with a shorter emission duration, particularly when displaying lower grayscale values.…”

92‐3: 1.63‐inch 403‐PPI Full‐color Active‐matrix LTPS Micro‐LED Display

“…Compared with current OLED wearable display, Micro-LED wearable display possesses the larger driving which demands the complicated TFT design and the stringent arrangement in the pixel circuit. Meanwhile, high PPI requires the more precise alignment of LED chips in the mass-transfer progress for LED chips transferring yield [8]. The speed and yield of masstransfer progress were regarded as an important consideration for manufactures to choose an effective and economical chips transfer way.…”