![]() If you want to use those different shapes for marking use only those easily recognized without a magnifying glass. The long lead is the anode and must be placed in the square solder pad. The silkscreen has this marked with a K Strait from the WIKI for REN64XC:-The LEDs are polarized and must be installed correctly. For polarized capacitors you may use different pad shapes for the + and - pin, same for diodes. The short leg (the Cathode or K) of the LED must go into the square pad. You might use those different pad shapes for marking of some pins, for instance pin 1 of an IC square, all others round. Routing traces not only with 0° and 90° but also with 45 ° fits better to octagon pads than to square or heaxgon pads. ![]() The octagon is a compromise between square and round. Triangles are possible too but their area is too small compared to a round pad.Ī round pad leaves more space for routing as a square pad. round for +/- on polarized caps, or for anodes/cathodes on diodes I am inclined to prefer. A key element of that accuracy is our understanding of your board and the component markings. Greetings: Is there a standard on which pad to make square vs. Even heptagons and nonagons are possible. PCB assemblers work hard to place every component, from the largest, highest pin-count logic chip, down to the smallest passive components and micro wafer scale BGAs, correctly every single time. You may also use pentagons and hexagons if you like as long as your PCB CAD system supports them. ![]() I've always approached LEDs like axial diodessquare pad for cathode. With only about 32 different apertures you could not chose between round, square and octagons.īut nowadays raster photo plotters are used and you may programm the sizes and shapes you wish. Posts: 364 David - Kennesaw, GA Re: LED pads’ convention Reply 1 on: April 10, 2019, 12:26:10 PM If Brian's Eagle libraries are any indication I think the 2012 version had square pad for cathode, but in more recent versions that's been reversed. The preferred method is to place the diode schematic symbol in the silk screen. ![]() Bag Box Bulk Cut Tape (CT) Retail Package Tape & Box (TB) Tape & Reel (TR) Tray Tube. To ensure the best accuracy, we recommend extra care in marking your diodes to remove any ambiguity. Dialight EAO Everlight Electronics Co Ltd. Decades ago when vector photo plotters with an aperture wheel were used you could only use those pads sizes and shapes that were present on the wheel. Guidelines for diode polarity mark silk-screening the diode symbol, K for Cathode or A for Anode or. Solder is a conductive material that melts around 400 degree Fahrenheit and allows two pieces of metal to connect in a circuit. ![]()
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