The beauty of eutectic solder is that it has a nice low melting point and that it solidifies over a very narrow temperature range. That is the magic formula of eutectic solder, 63% tin and 37% lead. Try not to be too creative.Īll of this happened while we had to give up on SN63 solder. Image Credit: Author - Sometimes, placement requires a little creativity. Get ready to work with values up to 0.1♟, 6.3vdc caps in 008004 (.25x.125mm) packages. Murata has a new class of capacitors below the size of 01005. Electronic component assembly that had 0.1” to work with now got down to 0.016” or less. Those devices have evolved from 1.27 mm pitch down to 1 mm then 0.8 mm followed by 0.65, mm, 0.5 mm, 0.4 mm and now 0.35 mm and even 0.3 mm in some cases. That’s still not enough so we filled up the entire bottom of the component with little solder bumps instead of actual leads. They go all of the way around in a quad-flat-pack arrangement. Not only that but the pins are not restricted to the two sides anymore. The first SMD components were half of that pitch but still, a 1.27 mm pitch device seems very coarse when we compare it to 0.5 mm of recent times. Metrically, we’re talking 2.54 mm and 7.62 mm respectively. The popular 14 and 20-pin DIP (dual in-line package) used a tenth of an inch between pins down the sides with three tenths across the package. The leads were formed so that they could be inserted into holes that were a half of an inch apart. Those Days Are GoneĪ resistor was big enough to have four or five bands of color so that we could determine the value and tolerance at a glance. Up to that point, we measured the pin to pin pitch in fractions of an inch. DIP packages were slowly being replaced by SOIC equivalents. Surface mount resistors and capacitors were just becoming a thing.

Image Credit: Author - FPGAs drive circuit density with flexible architecture.ĭoing more with less has been a central theme ever since I moved from the assembly line to the CAD cave. We’ve come a long way towards shrinking the products and that comes with the cost of shrinking the components. Through-hole components were a breeze to install and rework if necessary. Things have improved for the environment but I’m not so sure I can say that about the workers. It was hazardous to the environment and the assemblers. Did I ever mention that I worked on an assembly line? Yup, way back when we used lead in our solder and freon to clean the flux off of the boards.

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