ASM IC packaging device ASM PACIFIC: mass transfer is no longer a fundamental obstacle ASM Pacific recently gave an interview to Yole d éveloppement to explain the company’s Mini LED and Micro LED strategy and outlook. The research contents of two white papers, “2021 research white paper on Micro-spaced LED display”and “2021 Mini LED backlight development white paper,”are combined to explain in detail the technology and products of Asm Pacific Mini/Micro LED in massive welding. In 2016, Asm Pacific began to develop a Mini LED and Micro LED packaging solution, the early ASM Pacific through chip size to distinguish the two technologies (namely Mini LED: 50 m-200 m; Micro LED: Less than 50 m) . ASM Pacific recently changed its definition of a Micro LED to: There is no substrate like a Sapphire. In the packaging, the former process includes solidification and welding line, solidification is through the solidification machine to fix the new LED products in the support of the plate on the designated area of the process. With the reduction of the distance between the DOTS and the number of pixels per unit area, the number of LED chips needed to be solidified increases. ASM Pacific’s 1990 generation solid-crystal machine uses the traditional swing arm welding head, but can not meet the demand of chip miniaturization. In view of this, ASM Pacific independently developed a new welding head technology-vortex, to provide high-speed and high-precision COB solution for large LED display which needs to be fixed with small size LED chips. The VORTEX platform can handle Mini LED chips as small as 50 m x 100 M, providing high-speed, high-precision Pick & PLACE COB solutions for large LED displays. With XY θ calibration capability, VORTEX can achieve high speed and precision without sacrificing production capacity. With its powerful testing capability, VORTEX can provide high yield solution, after-welding testing to ensure welding quality. Therefore, it is especially suitable for ultra-micro distance RGB Mini LED direct display as small as P0.4.

Vortex features direct display of Mini LED micro-spacing and the LED chip needs to be soldered through a reflow oven after being placed on a printed solder paste substrate, which pushes up the LED chip and causes the angle of the LED chip to be tilted, therefore, LED display module lights up after the pitting phenomenon. To solve this problem, Asm Pacific introduced the Ad300mini and Ad300pro huge welding equipment, which can control the chip tilt angle within 1um, Ad300mini for Mini LED chip, Ad300pro for Micro LED chip.

Huge welding Mini LED designed for high-end RGB display screen design, and, Asm Pacific said, seal technology is still the Z popular, Z mature huge transfer concept, and laser technology is a viable Micro LED transfer process. The technological breakthrough is how to handle Micro LED epitaxial layer transfer only a few microns thick. ASM Pacific is developing a unique laser process for Micro LED transfer. As more test data is consolidated, it will be released to the market. Now Z common transfer seal size is 37x37mm, there are companies using 49x49mm size. The welding yield is greatly influenced by the coplanarity of seal and substrate. The chip size is usually 5-50m. Cycle time is highly dependent on materials and processes, whereas Asm Pacific’s alignment takes just a few seconds to weld one hundred thousand chips to hundreds of millions of chips at a time with 100% yield. Intermission: join the Mini LED display industry group, you can add VX: hangjia188.

So far, significant progress has been made in Micro LED migration. Asm Pacific believes that mass migration is no longer a fundamental barrier in 2021, as most important players can use the AD300Pro to achieve this goal. In order to realize the mass production product, the key should be in the front end and back end process, such as Micro LED wafer yield, sorting, welding, on board repair and so on. The huge transfer welding platform AD300Mini is mainly aimed at the quality requirement of RGB display screen. When reflow soldering can not reach this quality, the positioning accuracy is as high as ± 2 m, the angle accuracy is as high as ± 0.005 ° . Vortex quickly transferred the Mini LED chip from the sorted wafer to the temporary carrier, and then used the Ad300mini for in-situ massive welding.

In addition to solid-crystal welding, ASM Pacific developed the Ad420xl solid-crystal welding machine, which uses the Pick & amp; Place COB solution with high speed and high precision. Asm Pacific also offers Mini LED repair solution RW300. The RW300 is a one stop repair solution for RGB LED displays: De Crystallize and resolder the new chip. “A year or two ago, 5x9mil was the mainstream, but last year it was 4x8mil. Most customers have tested 3x5mil welds this year so they can produce chips at lower cost and be prepared for micro-pitch displays (less than P0.6) ,”said Asm Pacific, both Mini and Micro leds use high-density Matrix welding processes, which require high-speed and flexible packaging processes to drive low-cost, high-efficiency production. Asm Pacific is working in this direction, developing innovative devices to support mass production, and is working on front end and rework processes to integrate the complete solution to accelerate the commercialization of the product. It is worth noting that Asm Pacific, as the “2021 Micro-pitch LED display research white paper”and “2021 Mini LED backlight development white paper,”the a-level reference unit, more Mini/Micro LED equipment technology included in it, 5.7% off early bird now on sale.