Issue link: https://iconnect007.uberflip.com/i/1478618
34 DESIGN007 MAGAZINE I SEPTEMBER 2022 to the panel much like the traditional process. e LDI imaging process does not require a phototool as an intermediary during the exposure step. Eliminating the phototool and mylar or glass layer from the exposure process allows the light source to expose the photoresist more directly. is reduces interference and limits opportunity for the creation of air gaps in either of those two extra layers. By elimi- nating the mylar layer the quality of the image process improves. e thickness of the clear mylar layer being present does two things: scatters the light source as it transfers between multiple types of layers, and it increases the effective distance between the light source and its ultimate destination—the photore- sist. Eliminating this layer provides a more direct path from the light to create a sharp and defined image. Air gaps cause issues with the quality of the exposure and can cause defects by allow- ing exposure in areas where it is unwanted. LDI eliminates the part of the process that can cause air gaps, generating a sharper and truer representation of the data being trans- ferred. In traditional photo-based methods, the alignment of the image with the panel can be a very tedious, and in some cases, impossible task. e LDI process better aligns the image with the panel than with traditional methods. e LDI process uses aligning targets called fiducials to calculate any movement that has occurred in the panel and correct for it. We can also calculate and adjust for any stretch, shrinkage, or skew that has occurred during the previous manufacturing steps. e cop- per image is, for practical purposes, perfectly aligned with the drilled holes. e LDI imaging process makes my team better at our jobs. We have realized improve- ment in numerous areas because we adopted this method for imaging. Most importantly, we have improved the quality of our output and that reverberates throughout the PCB manufacturing process. e result is better boards. e boards are not just higher resolution, they take less time to produce. We don't spend Trina Taylor and Matt Stevenson reviewing a project at Sunstone.