Issue link: https://iconnect007.uberflip.com/i/1337116
34 DESIGN007 MAGAZINE I FEBRUARY 2021 turers are designing tiny 7 mm x 5 mm pack- ages with a gazillion pins underneath them. ey're bottom terminal only, and every pin seems to have a different size and location with a different solder and paste mask. ey'll have one page in the datasheet set aside just for the pad dimensions, another page for the pad locations, another page for the solder mask dimensions, solder mask locations, the paste mask dimensions and another of the paste mask locations. It gets to be really, really technical with a lot of geometry mathematics involved. Dieter Bergman and I tried to figure out how much money is being spent in the industry in library part creation for sche- matic symbols, footprints, and 3D models. We looked worldwide at all the companies, patterns, and boards that are being made. We concluded that to be an expense of about $1 billion a year. e $1 billion includes salaries, computers, CAD tool soware, furniture, training, and compensat- ing for errors and mistakes in library creation. A lot of revenue goes into PCB library cre- ation globally and the main reason why the yearly expense for creating PCB libraries is so high is because most companies create their own library parts using their company rule set and that contributes to massive duplication of effort. However, we can greatly reduce cost and error rate by having access to all the sche- matic symbols, standard package dimensions, non-standard manufacturer footprints, and 3D STEP models in a single location on the cloud. is is a tremendous never-ending project as the number of new component packages every week is overwhelming. is year, over 20 mil- lion brand-new electronic component part numbers will be introduced. Digi-Key currently has 11.5 million parts on its website. e Valor Parts Library contains over 35 million part numbers for PCB mount components. SiliconExpert supports data- sheets on over 1 billion electronic part num- bers for both current and obsolete parts. at's a lot of symbols, footprints, and 3D models. e concept of reducing cost and errors of PCB library creation is a reality. You need a so- ware program that only requires package and terminal lead dimensions, and tolerances and a user-defined set of options to define all your per- sonal library construction rules. is way you get consistent quality in your PCB library. Also, you can change any of your personal options or your CAD tool and regenerate your complete PCB library from scratch using your collection of package dimen- sions and tolerances. Matties: Well, this has been really good. Any final thoughts, Tom? Hausherr: I have one final thought. In your PCB library cal- culator tool, you have a nominal 1:1 scale image package outline and terminal leads; when the terminal leads fall somewhere on the pad, you'll be fine. It's when the pad falls away from the terminal lead that you run into trouble. And that's where the Valor PL and the 3D model can reduce errors. In our soware calculator tool, Footprint Expert, we draw the rectangular shape of the terminal lead on the pad, so when the user calculates the IPC pattern, enters the manu- facturer component recommended pattern dimension, and the pad falls off the terminal lead, you must go back to the IPC pattern. In this case, the manufacturer pattern dimen- sional data could have a typographical error. IPC's mathematical model for land pattern calculation comes all the way from the 1987 release of IPC-SM-782 for 18 years, into the IPC-7351, all the way up to today. Now, things are changing; tolerances used to be robust, but tolerances today are getting smaller and smaller, because the manufacturers are getting better, high-quality machines to manufacture their component packages.