Powering Display Fabrication Efficiency

The Coherent LineBeam LB1300-G8 annealing system lowers the cost of processing large Gen 8 panels.

 

July 11, 2023 by Coherent

LineBeam 1300-G8

The new Coherent LineBeam LB1300-G8 improves the efficiency of producing low-temperature polysilicon (LTPS) on the large Gen 8 substrate panels increasingly coming into use by display manufacturers. It accomplishes this by delivering a longer line beam – necessary to accommodate these larger panels – and optionally incorporating the revolutionary new Coherent PYTHON all solid-state laser, specifically designed for LTPS. 

 

OLED Displays Get Bigger

Organic Light-Emitting Diode (OLED) display manufacturers are aggressively moving to displace traditional Liquid Crystal Displays (LCDs) in devices such as laptops, tablets, gaming systems, and desktop computer monitors. This is because OLEDs offer a number of benefits over LCDs, particularly for mobile or handheld devices. These include better picture quality, lighter weight, more compact size (thinner), wider viewing angles, faster response times (important for video streaming and gaming), and greater electrical efficiency (which extends battery life). 

But making these so-called IT (information technology) panels poses a challenge for display manufacturers who have mostly geared their production around smaller smartphone displays. This is because the display fabrication process starts by creating numerous displays at once on a large “mother glass” panel. The individual displays are cut out from this panel later in the process. 

As the size of individual displays increases, fewer of them can be produced on a mother glass panel of a given size. But the cost of processing this panel stays about the same. So the unit cost of each individual display goes up. 

 

LineBeam systems

As display size goes up, fewer units can be produced on a given sized mother glass panel which increases the unit cost.

 

One solution for display makers is to increase the size of the mother glass to yield more displays per panel. But, of course, this assumes that the cost for processing the larger panel won’t scale up too dramatically. Otherwise, it won’t reduce the display unit cost sufficiently. 

 

Optimizing LineBeam for Gen 8 Panels

Coherent is well-established as the premier provider of LTPS annealing systems – in fact, virtually every major display manufacturer worldwide relies on our LineBeam systems. In the past, we have offered systems with four different line length options – 750 mm, 1000 mm, 1300 mm, and 1500 mm – to enable processing of all the different sized mother glass panels currently in use. 

Manufacturers now want to switch to the newest Gen 8 OLED panels which are 2290 mm x 2620 mm in size. These are much larger than previous generation panels and potentially offer the cost reductions display makers are trying to achieve.

If LTPS is performed by sweeping over the panel twice in the short direction, then a line length of at least 1310 mm (half of 2620 mm) is required to cover a Gen 8 mother glass. Of course, this can be achieved with the existing Coherent LineBeam 1500 – but the cost of that system doesn’t provide the economy that display manufacturers require. 

The LB1300-G8 was designed specifically to deliver the increased efficiency necessary for economical processing of Gen 8 panels. It provides a line length sufficient to process them in the double pass configuration with economics that make it very attractive to manufacturers. 

The other great feature of the LB1300-G8 is that it is compatible with either Coherent VYPER or PYTHON lasers. The PYTHON is a diode-pumped, solid-state (DPSS) laser developed to deliver essentially identical output characteristics as our VYPER Excimer laser, but with significantly lower cost-of-ownership.  

The Coherent LineBeam LB1300-G8, particularly when configured with Twin PYTHON lasers, enables display makers to manufacture high volume LTPS backplanes on Gen 8 substrate panels with the highest yield and greatest efficiency. 

Learn more about the Coherent LineBeam LB1300-G8.