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  • EEVblog #408 – Schmart Board 0.4mm QFN SMD Soldering

    Posted on January 8th, 2013 EEVblog 11 comments


    Mailbag continued.
    Soldering a 0.4mm QFN chipscale SMD package onto a Schmart Board using 0.3mm JBC and Hakko tips.
    Also a demonstration of drag soldering with a chisel point tip.

    Schmart board
    Green Arrays Multi-Processor Chip

    Forum Topic HERE

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    • huh

      Dave, what solder wire are you using? SnPb or lead free?

      • http://www.eevblog.com EEVblog

        Lead, all the way.

    • JRR

      Is there a way for a hobbyist to lay out grooves like that in a standard PCB layout (I only do at most 200 small boards at a time using Chinese suppliers like PCB Cart) or is a specialized process used to create the grooves?

      How much difference do you feel there is between a good solder mask and the grooves? The tightest I’ve hand soldered with just a solder mask board is 0.65mm SSOP, and that was a bit tricky but not horrible with just a chisel tip and a hand lens to inspect.

      • http://www.schmartboard.com Neal Greenberg

        JRR: It is possible to make custom boards and we do work with corporations and hobbyist groups to do so. It is more costly than a regular PCB due to added labor and time. For general information you can go to : http://www.schmartboard.com/index.asp?page=services_custom

    • http://www.schmartboard.com Neal Greenberg

      Dave: Thanks for taking such a thorough look at our technology. When we first released the “EZ” technology with the grooves in 2005, it was for SO and QFP type devices, devices with real legs. The recommended manner of pushing the solder on the grooves worked great.(It was also pre-RoHS so you could work with a lower temperature) We felt that even someone who was terrified of surface mount could have success. Using this technique does require that you “tin” the tip of your iron periodically, especially when soldering a larget component. Today we support for instance .5mm QFP up to 240 legs.

      Drag soldering works fantastic with our product as you discovered. While it does require a little skill though, it is easier to drag solder our products than a normal PCB. For legless boards such as QFN/DFN or for larger components such as 88 leads, it is most certainly the preferred method. We do mention this on our QFN product pages.

      Thanks again though for taking a peak. Have a fantastic 2013.

    • Manwolf

      Thanks I had looked at them before and wondered how they worked. Ended up using dragging as well.

    • Infi

      Dave, for this work, i use hot air soilder station, it`s 5 times faster!

    • Hans

      Can you make this episode ready for torrent download?

      Download from you site do not work that well from here.

      • http://www.eevblog.com EEVblog

        Sorry, eevblog.org is down at the moment, and that is where bitlove reads it’s files from.

    • http://e-motion.lt elektrinis

      You don’t need a fine tip for that. I use flat end, like 3mm wide tip to solder chips like this. Just solder several pins at once and the flux will do the job. Saves a lot of time.

    • Yansi

      Well… no point four… I have to solder some crazy 0.3 FFC connector for a display panel. It will be fun!