Issue link: https://iconnect007.uberflip.com/i/1494936
56 PCB007 MAGAZINE I MARCH 2023 Introduction In last month's column, I framed the initial challenges for the PWB fabricator to be suc- cessful in producing IC substrates to support advanced packaging. In this month's feature, I'll explore two more areas of processing that fabricators need to master: • Imaging/developing • Etching Fine-line Imaging/Developing One must understand that photolithogra- phy is the cornerstone of advanced packag- ing and IC substrate production. Laser direct imaging is now a must for high density and ultra-high density substrate fabrication. When pushing the limits of ultra-high density, conventional contact printing falls short. Usher in the devel- opment and implementation of laser direct imaging (LDI). e capabilities of LDI systems provide sev- eral advantages over contact printing. Exam- ples include the fabrication of boards with tight registration tolerances. In addition, the pattern is printed directly from the CAD sys- tem and does not require a phototool. With respect to contact printing, registration errors occur due to dimensional changes in either the phototool or the panel. ese dimen- sional changes happen because the materials used for the mask and panel (such as FR-4) vary in size as a function of temperature and h u m i d i t y (which are con- Processes to Support IC Substrates and Advanced Packaging, Part 2 Trouble in Your Tank by Michael Carano, IPC CONSULTANT