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Re: [softrock40] Here We Go - My First Newbie Question

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  • KD5NWA
    ... Below is a link to a tutorial on using a toaster oven to solder double-sided SMT boards. On the article is a link to sites with tutorials on two other
    Message 1 of 7 , Jan 1, 2007
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      w6ids wrote:
      > First off, Happy New Year from our home to all of yours!
      >
      > Secondly, I have a question regarding SMT assembly as a
      > hobbiest. My experience with SMT was quite some time
      > back and involved commercial environments to include
      > SMT component placement and ovens of the commercial
      > level. Inspection used "stereo scopes" to inspect filets,
      > flow, etc.
      >
      > That said, just what are you folks doing to properly install
      > and solder the components to the board(s)? Do you bring
      > the kitchen oven or toaster oven up to around 375 Deg F
      > with a dial/digital thermometer inside or ??? Hmmm, I'm
      > wondering if I need to spend a couple of hundred dollars
      > for a suitable oven for the bench top?
      >
      > How are you applying solder paste without considerable
      > waste? Do you perform a post-solder fluxing step?
      >
      > How are the hobby assemblers inspecting their work?
      > Personally, my eyesight at 62 is just not good enough to
      > simply eyeball solder quality in SMT applications.
      >
      > What happens if there is a component shift during the
      > soldering creating misalignment or perhaps there is a
      > solder bridge or two?
      >
      > How much difficulty is experienced doing PCBs that have
      > components on both sides?
      >
      > That's it for now. Many thanks in advance for helping with
      > my learning curve.
      >
      > Regards,
      >
      > Howard W6IDS
      > Richmond, IN
      >

      Below is a link to a tutorial on using a toaster oven to solder
      double-sided SMT boards. On the article is a link to sites with
      tutorials on two other methods, "embossing air gun" and a "skillet"
      method for single sided boards only. Cash Olsen's site makes available
      small quantities of soldering paste, it goes a long way.

      You should never use a oven or a skillet for cooking food once you have
      soldered boards in it, unlike you like the idea of lead poisoning and
      insanity. A gas oven would be useless anyway since to solder the parts
      and not damage them you temperature must be controlled and go up at a
      controlled rate, a large home oven is not capable of doing that.


      < URL:http://www.hpsdr.com/Public/Projects/SMT/SMT.html >

      --

      Cecil
      KD5NWA
      www.qrpradio.com www.hpsdr.com

      "Sacred Cows make the best Hamburger!" Don Seglio Batuna
    • FRANCIS CARCIA
      I lay a hunk of solder next to the first joint so there is a bit of flux to make the connection. Graham Haddock wrote: Howard:
      Message 2 of 7 , Jan 1, 2007
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        I lay a hunk of solder next to the first joint so there is a bit of flux to make the connection.

        Graham Haddock <GrahamH@...> wrote:
        Howard:

        So far, I have not used or had to use an oven.

        I use a short conical point controlled temp (700 deg F)
        soldering iron, 0.015 dia Kester 44 solder, a lighted
        ring magnifying lens/lamp (for assembly), and a
        4X jewelers eye loope for inspection. For removing
        excess solder and bridges, use small size solder-wick.

        Use fine tweezers for holding and placing the chip parts.

        Anti-static mat and wrist strap for assembly of anything
        that is static sensitive.

        There are several tutorials on the web about hand assembly
        of SMT parts.

        For chip C and R, I put a small dot of solder on the board
        on one end, hold the part with tweezers while I reflow the
        solder with the soldering iron on that end. When the part
        is where I want it, go the the other end and solder it.

        For ICs, put a small solder dot on the board for one corner
        pin, hold the IC with tweezers until correct placement and
        then melt the solder at that first pin. If necessary, twist the
        IC slightly to get all pins to register, then solder one
        pin diagonally across the IC. Double check all registration.
        Adjust if necessary by melting solder at one or the other
        of the two soldered pins.
        If registration is OK, go down the row of pins on all sides
        soldering the pins. Excess solder and pin to pin bridges
        is OK at this point, most important is to solder each pin.
        Then, with solder wick, go back down each row and pick up
        the excess solder, and any bridges. You can get very a
        good looking IC installation this way.

        If you try to individually solder the pins on a fine pitch
        IC without pin to pin shorts, you will go nuts. The trick
        is to put a little extra solder on the pins, get good solder
        joints,don't care about bridges, then pick it up later with
        the solder wick

        --- Graham

        ==

        w6ids wrote:
        >
        >
        > First off, Happy New Year from our home to all of yours!
        >
        > Secondly, I have a question regarding SMT assembly as a
        > hobbiest. My experience with SMT was quite some time
        > back and involved commercial environments to include
        > SMT component placement and ovens of the commercial
        > level. Inspection used "stereo scopes" to inspect filets,
        > flow, etc.
        >
        > That said, just what are you folks doing to properly install
        > and solder the components to the board(s)? Do you bring
        > the kitchen oven or toaster oven up to around 375 Deg F
        > with a dial/digital thermometer inside or ??? Hmmm, I'm
        > wondering if I need to spend a couple of hundred dollars
        > for a suitable oven for the bench top?
        >
        > How are you applying solder paste without considerable
        > waste? Do you perform a post-solder fluxing step?
        >
        > How are the hobby assemblers inspecting their work?
        > Personally, my eyesight at 62 is just not good enough to
        > simply eyeball solder quality in SMT applications.
        >
        > What happens if there is a component shift during the
        > soldering creating misalignment or perhaps there is a
        > solder bridge or two?
        >
        > How much difficulty is experienced doing PCBs that have
        > components on both sides?
        >
        > That's it for now. Many thanks in advance for helping with
        > my learning curve.
        >
        > Regards,
        >
        > Howard W6IDS
        > Richmond, IN
        >
        > __._,_.
        >
        >


      • Bill Dumke
        Howard, Use plenty of rosin flux. You can buy it from DigiKey or Mouser in a syringe. You can also apply it with a toothpick. I put some on each pad I am going
        Message 3 of 7 , Jan 1, 2007
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          Howard,

          Use plenty of rosin flux.  You can buy it from DigiKey or Mouser in a syringe. You can also apply it with a toothpick. I put some on each pad I am going to solder.  Then after I am done soldering, I wash the flux off with CRC Brakleen, the red can version.  But do it out of doors.  You can get this at any auto parts store.  It works great on rosin flux.  The old fashioned flux cleaners such as trichlor are difficult to get these days due to health risks.  And I have found the expensive electronics supply house flux cleaners don't work any better than Brakleen, anyway.  A side benefit of washing the flux off is you can detect the solder bridges a lot easier, as well as giving more integrity to high impedance and low capacitance circuits.  You can also use a Q-tip swap to help clean up as well. 

          Bill WA9PWR

          w6ids wrote:


          First off, Happy New Year from our home to all of yours!

          Secondly, I have a question regarding SMT assembly as a
          hobbiest. My experience with SMT was quite some time
          back and involved commercial environments to include
          SMT component placement and ovens of the commercial
          level. Inspection used "stereo scopes" to inspect filets,
          flow, etc.

          That said, just what are you folks doing to properly install
          and solder the components to the board(s)? Do you bring
          the kitchen oven or toaster oven up to around 375 Deg F
          with a dial/digital thermometer inside or ??? Hmmm, I'm
          wondering if I need to spend a couple of hundred dollars
          for a suitable oven for the bench top?

          How are you applying solder paste without considerable
          waste? Do you perform a post-solder fluxing step?

          How are the hobby assemblers inspecting their work?
          Personally, my eyesight at 62 is just not good enough to
          simply eyeball solder quality in SMT applications.

          What happens if there is a component shift during the
          soldering creating misalignment or perhaps there is a
          solder bridge or two?

          How much difficulty is experienced doing PCBs that have
          components on both sides?

          That's it for now. Many thanks in advance for helping with
          my learning curve.

          Regards,

          Howard W6IDS
          Richmond, IN

        • kerrygeek1
          I used the method on Cash Olsen s web site using the hot air gun, solder paste and a coffee cup warmer. I got the heat gun locally on sale at Hobby Lobby for
          Message 4 of 7 , Jan 1, 2007
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            I used the method on Cash Olsen's web site using the hot air gun,
            solder paste and a coffee cup warmer. I got the heat gun locally on
            sale at Hobby Lobby for $12 and the cup warmer at Walgreen's for
            $3.00. I ordered the solder paste from Cash on his web site, so far
            we've used it to build 2 boards and haven't even made a dent in it.

            I'm no spring chicken either (47 next month) but a pair of cheapo
            reading glasses (also from Walgreen's) and a gooseneck light clamped
            to the edge of the desk was all I needed. I borrowed a lid of a cake
            pan to keep the parts from rolling off the desk, it's now back in the
            kitchen and my wife didn't even miss it.

            Don't worry about the smt parts, I was sweating it but it was actually
            the easiest part of the project. I was wishing more of the board was
            SMT. The other parts took much longer than the SMT parts.

            73,
            Kerry


            --- In softrock40@yahoogroups.com, "w6ids" <w6ids@...> wrote:
            >
            >
            > First off, Happy New Year from our home to all of yours!
            >
            > Secondly, I have a question regarding SMT assembly as a
            > hobbiest. My experience with SMT was quite some time
            > back and involved commercial environments to include
            > SMT component placement and ovens of the commercial
            > level. Inspection used "stereo scopes" to inspect filets,
            > flow, etc.
            >
            > That said, just what are you folks doing to properly install
            > and solder the components to the board(s)? Do you bring
            > the kitchen oven or toaster oven up to around 375 Deg F
            > with a dial/digital thermometer inside or ??? Hmmm, I'm
            > wondering if I need to spend a couple of hundred dollars
            > for a suitable oven for the bench top?
            >
            > How are you applying solder paste without considerable
            > waste? Do you perform a post-solder fluxing step?
            >
            > How are the hobby assemblers inspecting their work?
            > Personally, my eyesight at 62 is just not good enough to
            > simply eyeball solder quality in SMT applications.
            >
            > What happens if there is a component shift during the
            > soldering creating misalignment or perhaps there is a
            > solder bridge or two?
            >
            > How much difficulty is experienced doing PCBs that have
            > components on both sides?
            >
            > That's it for now. Many thanks in advance for helping with
            > my learning curve.
            >
            > Regards,
            >
            > Howard W6IDS
            > Richmond, IN
            >
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