Laser Direct Imaging (LDI) is an advanced exposure technology for complex and HDI PCB manufacturing. With LDI, patterns are plotted on a digital file, instead of the phototool of old, and those digital files are uploaded into the LDI, which will selectively image it on PCB substrate. Instead of using a form of UV lamp as the source for the plotting, the direct imager uses a concentrated beam of UV energy generated by a solid-state laser. This laser is incredibly precise, capable of imaging 2mil lines and spaces. An LDI also uses a built-in camera system which, given the pattern is aligned properly on the substrate, has a back to front registration accuracy of 1mil.
