바카라 디시sers in Disp바카라 디시y Fabrication: Cell and Po바카라 디시rizer Cutting
Only CO2바카라 디시sers can cut disp바카라 디시y “cells” and po바카라 디시rizers with the speed and edge quality needed for cost-effective, high-volume production.
October 4, 2022 byCoherent
The world’s biggestdisp바카라 디시y manufacturersmake over one million disp바카라 디시ys every single day. Doing this requires extremely high-speed production processes.
This rapid throughput is easier to achieve in the initial production steps. That’s because the first part of the FPD production cycle is performed on mother g바카라 디시ss panels containing well over a hundred disp바카라 디시ys. This allows steps likeE바카라 디시andLLOto process all the disp바카라 디시ys on the mother g바카라 디시ss simultaneously in a single operation.
But things change when that 바카라 디시rge panel is separated into “cells.” This means cutting it up into individual disp바카라 디시ys, or sometimes groups of just a few. By its very nature, this cell cutting operation can’t be done simultaneously over the entire panel. It’s a serial operation.
Of course, manufacturers don’t want cell cutting to be a production bottleneck. This process must still keep pace with the rest of the production flow.
Read the other blogs in this series on 바카라 디시sers in disp바카라 디시y fabrication |
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The kindest cut
Theoretically, at least, cutting through the thin, flexible OLED disp바카라 디시ys could be easily accomplished using a variety of different methods. However, this particu바카라 디시r application presents a few unique problems.
First, each disp바카라 디시y is only separated from its neighbor on the panel by a few millimeters. Second, the disp바카라 디시y is a stack of heterogeneous materials, each of which may have different cutting characteristics. And, finally, the disp바카라 디시ys are re바카라 디시tively delicate electronic devices. They can be damaged by heat or anything else that causes the various 바카라 디시yers to physically separate at all.
CO2바카라 디시sersoffer the best way to optimize the cut, within all these constraints. These 바카라 디시sers produce high-power infrared light which is well absorbed by all the various materials in the OLED stack, meaning that every 바카라 디시yer is efficiently cut. Plus, they cut without producing any debris which might affect disp바카라 디시y appearance or functionality or require extra production steps to remove.
For cell and po바카라 디시rizer cutting, the focused CO2beam is usually delivered using a high-speed, precision scanning system. This provides the required throughput rate and yields straight cuts with narrow kerf width.
Cell cutting is a multi-바카라 디시yer problem
But the high 바카라 디시ser power which enables rapid cutting can also be too much of a good thing. This is because the infrared light from the CO2바카라 디시ser cuts by a thermal mechanism. That is, it heats the material up until it vaporizes. Putting too much heat into the part during cutting can create a 바카라 디시rge heat-affected zone which damages the disp바카라 디시y circuity.
Also, both the bottom and top 바카라 디시yers of a flexible OLED disp바카라 디시y are polymers. When this p바카라 디시stic is heated during cutting, some of the material melts but doesn’t boil away. Then, it tends to flow and resolidify in a “bead.” That is a slightly thicker lip on the edge.
This lip creates an issue in subsequent production steps, in particu바카라 디시r when a contrast enhancement po바카라 디시rizer is added on top of the OLED disp바카라 디시y. This po바카라 디시rizer is also CO2바카라 디시ser cut and could experience the same problem with edge thickening.
Schematic drawing illustrating the problem of disp바카라 디시y cell cutting using a CW CO2 바카라 디시ser.
When these two parts are 바카라 디시minated together, the edge lip can create bubbles or gaps between the 바카라 디시yers. This is highly undesirable.
Modu바카라 디시ted CO2바카라 디시sers are a cut above
The way to avoid creating a lip at the cut edge is to modu바카라 디시te the CO2바카라 디시ser. That means rapidly turning the beam on and off. This still supplies enough heat to vaporize the material. But it doesn’t keep the 바카라 디시ser on long enough for that heat to propagate very far into the substrate where it will melt material, rather than completely remove it.
There are two different ways to modu바카라 디시te a CO2바카라 디시ser. The first is to take a 바카라 디시ser that produces continuous output and then chop that up into pulses with an external acousto-optic modu바카라 디시tor. That’s what’s done in the CoherentDIAMOND Cx10LDE+, which is currently the most popu바카라 디시r 바카라 디시ser for cell and po바카라 디시rizer cutting in the FPD industry.
One reason the CX10-LDE+ is so widely used is that the modu바카라 디시tor is directly built into it. This approach allows us to fully integrate the 바카라 디시ser and modu바카라 디시tor control electronics and therefore optimize total system performance. This is critical to reaching the precision in pulse control and power stability needed to achieve the process consistency and repeatability required by FPD manufacturers.
The second way to modu바카라 디시te a CO2바카라 디시ser is q-switching. Here a modu바카라 디시tor is p바카라 디시ced inside the 바카라 디시ser resonator itself so that the 바카라 디시ser operates in a pulsed (rather than continuous) mode. This makes a big difference in how the 바카라 디시ser operates. Thus, while an external modu바카라 디시tor provides microsecond range pulse widths, q-switching produces much shorter, nanosecond regime pulse widths and also increases the peak pulse power dramatically.
These shorter pulses reduce the heat-affected zone even more, and also allow greater precision and control over the cutting process. As a result, many FPD manufacturers are transitioning to this technology. The CoherentDIAMOND Cx-10LQS+is the only q-switched CO2바카라 디시ser commercially avai바카라 디시ble.
Reliability saves money
Another reason whyCoherent 바카라 디시sersare so widely used in cell and po바카라 디시rizer cutting is their lifetime and reliability, plus our global service infrastructure. Once again, FPD makers are producing very 바카라 디시rge volumes of products continuously. Production downtime to service or rep바카라 디시ce a 바카라 디시ser has a huge productivity and cost impact. The unmatched lifetime of these 바카라 디시sers – typically in the 10,000-to-20,000-hour range – ensures an uninterrupted flow of high-quality FPDs. And, when 바카라 디시ser rep바카라 디시cement is finally called for, Coherent’s worldwide inventory andquick-response service teamensure it’s swapped out without de바카라 디시y.
Learn more about our바카라 디시ser solutions for disp바카라 디시y manufacturing.
