Issue link: https://iconnect007.uberflip.com/i/1419905
18 PCB007 MAGAZINE I OCTOBER 2021 need it, but we're going to keep it there until we're darn sure. Matties: With the induction press, you can do heat up and cool down all under pressure in the same process. Is it your intent to do it that way? Will it yield better results? Patel: Exactly. It seems like a game changer. Matties: With that rapid heat up, it really does. With the press, you can make that material glow if you want it to. Patel: Yes. We can do fusion bonding on there too. Matties: Any final thoughts you have or advice for board shops on capital expenditures, whether it's planning, or any other insight that you want to share? Patel: I would recommend that the more com- munication you have with everyone inside the plant, the better—the sales guys, the custom- ers. Get the whole picture as much as you can. It just seems like a point in time where you shouldn't be afraid to take on a little bit more risk. Matties: Great. anks for speaking with us today, Sunny. PCB007 By Luca Gautero The digital form of inkjet printing technology oper- ates on files containing a rasterized image; these bitmaps, in their simplest form, contain information about the presence (or absence) of drops. Addition- ally, the resolution brings in the drop's pitch. This rep- resents a 2D view of a pattern. Such a pattern might, once printed, have a thickness, however, the raster- ized image does not carry this information. For pure 3D printing, the solution is to assign a fixed height step to each printed layer. Elegant and simple: each drop approximates a brick of fixed length, width, and height. This works reasonably well when the approx- imated drop dimensions are far below the tolerance needed for the application. For solder mask requirements, however, this is not the case. Features in PCB designs span sev- eral orders of magnitude with their length and width. The smallest feature is only one, two, or three times the size of a drop depending on the hardware choice (see my August column, "Printhead Selection or 'Shop 'Til You Drop'"). As a bridge between the bitmap definition and the final pattern, it is useful to define the outflow length of a drop (L of ). This length is the difference between the bitmap pattern length and the final length of the printed and cured feature. Additive Reality: Solder Mask Patterning at the Edge Between Drops and Bricks Since the digitally defined bitmap pro- vides control of the pattern, adding a re- producible L of extends the reproducibility all the way to the print- ed image. The proper place to implment this extension is be- tween the vector for- mat CAM definition of the pattern and the subsequent gen- eration of the raster- ized image. At this moment, geometrical features defined by coordinates become bitmaps. The L of length becomes the resizing length for features that need to be printed. Similar intervention on vec- tor formats are already common to compensate under-etch or over-etch during wet processing for etching. To read this entire column, click here. Luca Gautero is product manager at SÜSS MicroTec (Netherlands) B.V. Luca Gautero