Issue link: https://iconnect007.uberflip.com/i/1417991
44 DESIGN007 MAGAZINE I OCTOBER 2021 Gerber-Based Package Example To illustrate the low efficiency of a solder paste stencil design/preparation using Ger- ber data, three cases are presented. In Case A, a stencil issue leads to a quality event where the line is stopped during production to find the root cause, prepare a new stencil, and restart production, resulting in a 10-day deliv- ery delay. In Case B, there is a long require- ments preparation cycle in which the manu- facturing process engineer screenshots with CAM350, then prepares the requirements with an Excel spreadsheet, which takes seven hours for the requirements preparation and a total stencil preparation cycle of 2.5 days. In Case C, repeated communication efforts are required in which, upon receiving the design from the stencil house, the manufacturing process engineer must confirm the design, which takes four verification and explanation cycles, resulting in eight hours for communi- cation/validation and six hours for require- ments preparation, for a total stencil prepara- tion cycle of three days. Figure 3 summarizes the low efficiency of these cases using Gerber- based packages. Manufacturing Feedback Challenges All manufacturers run DFM analysis on designs to ensure manufacturability under their particular processes. DFM analysis also has issues to the disparate electronic paper files. e design house must correlate the files, interpret the data, respond to the queries, and approve or reject the request for change. is second phase of communications and feedback results in additional manual effort and time. e same thing happens with fab and test, and assembly and test as well. If the design violates too many of the manufacturer's guidelines, it must either be rejected as unmanufacturable, or the yield will be so low that manufacturing will not be cost effective. IPC-2581: Intelligent PCB Design Handoff to Manufacturing IPC-2581, an IPC standard, has existed since 2004. At that time, iNEMI brokered an agree- ment between IPC and Valor (the company that owned the ODB++ format at the time). With that agreement, IPC's GENCAM and ODB++ were merged to create IPC-2581. With IPC-2581, the handoff process can be performed much more efficiently and cost- effectively without the need to "dumb down" the data, segregate it into multiple pieces, and reverse-engineer it. Using IPC-2581, design- ers can create a single file that has everything the manufacturing partner needs to fabricate, assemble, and test the PCB, eliminating the struggle with multiple files and back-and-forth communication between the design and man- ufacturing sides. Table 1 highlights, from the manufacturer's view, how deep in the manufacturing process the IPC-2581 format goes vs. Gerber- and ODB++-based packages. It delivers greater value by eliminating much of the manual intervention. Duplicate data, such as PCB out- line dimensions, is also cut and an external Figure 3: The results of using low-efficiency Gerber data.