Connect with us

recomendations for soldering iron for smd & through hole components

Discussion in 'Electronic Basics' started by krem, Apr 14, 2004.

Scroll to continue with content
  1. krem

    krem Guest

    Hello, I'm looking for some advice on what to look for in a soldering iron.
    I'm going to mainly be using it for through hole components but will have
    the occasional SMD part to place. Before today I had two irons, one 15watt
    i used for smaller components and a larger 45 watt I used for larger tasks.
    The 15watt died on me with a big flash today, not really sure what happened
    but the set screw broke about two months ago letting the heating assembly
    rotate in the shaft of the iron so my guess is it shorted at some point. I
    know not really the smartest of things to keep using but it seemed to work
    well. anyways the 15 watt always seemed a bit low to me, at times not
    getting the components up to soldering temperatures just over heating them.
    I feel like I should get something around 25 watts but again not really
    sure. Not to mention a brand if it is felt there is one better than
    another. I know weller has excellent stations as well as irons but I'm
    looking to keep this fairly reasonable with pricing. Any thoughts or
    suggestions are welcome, I'm always looking to broaden my knowledge base.

    On a side note any recomendations on a de-soldering method? I've never used
    any tools other than the iron which has lead to some ugly jobs.
     
  2. Garrett Mace

    Garrett Mace Guest


    While a Weller or other temperature-controlled solder station is going to be
    the best, I've had good results with one of Antex's small pencil irons:
    http://www.antex.co.uk/ You can get tips in many different shapes and sizes.
    The price is also very very low; under $30 for the iron and about $5 for
    each tip. I got mine from HMC electronics: http://www.hmcelectronics.com
    (right now they have a stupid thing preventing browsers other than Internet
    Explorer from working, switching user agents doesn't fix it)

    As for desoldering: I have no patience with solder-suckers and the
    huge-solder-blob method, and I only use solder wick to clean up
    surface-mount solder bridges. My method of choice is to mount a heat gun
    somehow over the circuit board, and run it just until the solder melts. Any
    component can be removed this way; I've used it up to PQFP-208. You can
    remove a large QFP in under a minute with this method. No fiddling around
    with solder wick, thin steel wire, or anything like that. You need to take
    care to mask off plastic parts and anything you don't want to desolder,
    usually with a couple layers of aluminum foil. Also take care to shut down
    the heat gun as soon as the solder melts; this ensures that the internal
    chip temperature doesn't rise too high. Since you are heating the pins
    quickly, there shouldn't be enough time for the internal die to exceed 430F.
    If you are scared of overheating the chip, you could put a small ceramic
    tile or something on top of the chip; I've never destroyed a chip this way,
    though it is possible if you leave the heat gun on too long. Be careful of
    any nearby components like chip capacitors; they'll be loose too.

    To desolder two-terminal surface mount chip components, the best way is to
    add a little solder to one side so you have a larger bead there. Then you go
    to the other side and melt it; since the larger bead of solder holds heat,
    it will still be melted if you work fast enough. Then you can quickly remove
    the component with tweezers or just slide it off into the solder mask with
    the tip of the iron.

    So there's your complete soldering and desoldering solution, for about $50.
    Keep that larger soldering iron around, I still use one for soldering larger
    surface-mount chips quickly.
     
  3. Whatever kind you get, it should be temperature regulated. Then the
    wattage is not so important, as long as it is enough.

    I like the Hakko irons like this one:
    http://www.wassco.com/9360wsolstat.html

    Prices vary wildly from different distributors. Shop around.
     
  4. John_H

    John_H Guest

    You don't say what mains voltage you have available and you've also
    crossposted to a number of groups that encompass a range of
    possibilities... thus the equipment available is likely to vary
    somewhat depending on where you are. I'm answering from a 220-240Vac
    50hz perspective.

    I've got both Weller and Hakko stations on the bench (saves time
    changing tips). They're both good outfits, with Weller having the
    edge for range of tips (and price). Away from the bench I rely on an
    Antex CS (230V 18W) to do much the same job. Tip temperature is
    comparable to a 400°C setting on a soldering station and is relatively
    stable on standby. Unless you're doing production runs (or need to
    have the iron running all day) the soldering performance is also
    comparable on a typical joint. Where to get one and what it's likely
    to cost will probably depend on where you are (around 20% the cost of
    a Weller station where I am).

    You can also get temperature controlled mains powered irons for around
    half the price of a soldering station, which are OK until they need
    parts. I once had a Weller (until it shat itself) and Antex also list
    one.
    Unless your budget extends to a de-soldering station desoldering wick
    is the way to go for through hole components -- I like Hakko but
    there's plenty of brands to choose from.

    There's also various tricks for SMD, including special tips (if you
    can justify the price). One method I find handy for removing
    cockroaches is the low melting point alloy which is added to the
    existing solder joint -- you can then lift the component off the board
    before the joint sets. The one I currently use is "PRB Line" but
    there's probably others.

    I'm in Australia BTW. :)
     
  5. krem

    krem Guest

    ROT13.

    point well taken, i should have included i'm from the US 120v 60hz
     
  6. krem

    krem Guest

    alright trying to get all of this down. All of the advice is well taken, i
    was hoping not to spend much more than around 50-60 dollars, i now see to
    get a good station i'm dreaming for that price. I was wondering if anyone
    has ever made a soldering station from less expensive parts? Just looking
    for a cheeper option, this was sparked by my current 45 watt iron which is
    labled "120v 45watts ac/dc" I was supprised at the ac/dc part of that.
    Could one build a 120v dc supply and then adjust the voltages to control
    temp? Not really sure it would make sense that you could but its only a
    guess. again any input is welcome.
     
  7. Guest

    Keep this method of soldering surface mount devices in mind,
    particularly when you have many components to mount..
    http://www.seattlerobotics.org/encoder/200006/oven_art.htm

    Robert Lacoste recently won a Circuit Cellar contest with his version
    http://www.circuitcellar.com/renesas/winners/3323.htm
     
  8. Graham W

    Graham W Guest

    [...]
    Controlling the voltage going into the iron isn't the problem, it's
    getting
    a reliable form of feedback of bit temperature that is hard to do.

    As an over simplified example case, you could use a variac to reduce the
    voltage such that the bit temp temperature was suitable for most jobs,
    but it won't handle a sudden demand for more heat.
     
  9. Rich Grise

    Rich Grise Guest

    Yes, you could. It's able to run on AC and DC because the heating element
    is a pure resistance, i.e. negligible reactance.

    But it'd be way overkill, unless you have the 120 DC supply on hand. It'd
    be much simpler to get an ordinary SCR or Triac phase-control light dimmer
    for about 5 or 10 bucks.

    I have an iron that I cut one of the power leads and put in a switch
    and diode. When the switch is closed, it goes full-heat. When it gets
    warmed up, I open the switch, and there's a diode in parallel with it,
    so it's in series with the element, so it cuts the RMS power value to
    ..707 of the full-on value. Works pretty good, actually.

    Good Luck!
    Rich
     
  10. During high school, I made a iron holder that had this circuit in the
    base. When the iron was on the stand, its weight pushed down on a
    small micro switch, that opened, and it got half voltage. When it was
    picked up, it went to full power. Made the tips last much longer
    without burning up and didn't overheat the work. Not temperature
    controlled, but much closer to it. I could leave it on all day and it
    was ready to go when I needed it, without a lot of cleaning.

    Then I got a temperature controlled iron.
     
  11. Maybe a used Weller WTCP* series from Ebay? They last forever, and
    only used to cost $64 or so. The WTCPT is $138-ish at Contact East...
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-