Solder and Soldering Irons

Discussion in 'DIY' started by JK47, Nov 28, 2015.

  1. joch

    joch Friend

    Friend
    Joined:
    Oct 8, 2015
    Likes Received:
    113
    Trophy Points:
    43
    Location:
    the other side of the ocean
    Hope somebody has experience with what I'm looking to do.

    I want to replace an opamp from a board with a DIP8 socket for rolling. The opamp is in a tight but not impossible place. I guess the simplest is to just snip the legs and then use an iron tip to push through the rest and cut my losses with the opamp (sorry if you're pun sensitive).

    I also understand that an ordinary heat gun might do the trick? Or would that affect the other soldered pieces around it?

    Appreciate any advice for consideration.
     
  2. Riotvan

    Riotvan Got lost for three weeks at Delft City Hall

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    2,654
    Trophy Points:
    113
    Location:
    The Netherlands
    Get some desolderbraid and it should be easy enough. Or a desoldering station but those are expensive.
     
    • Like / Agree Like / Agree x 1
    • List
  3. fishski13

    fishski13 Friend

    Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    393
    Trophy Points:
    63
    Location:
    Twin Cities, MN
    If you don't mind trashing the opamp, snipping and clearing the holes is an option, otherwise desoldering could be done with something like Chip Quick, braid and a solder sucker. Clearing holes is best done with a sucker.
     
    • Like / Agree Like / Agree x 3
    • List
  4. ziptrickhead

    ziptrickhead Rando

    Joined:
    Dec 28, 2017
    Likes Received:
    1
    Trophy Points:
    3
    Location:
    NYC
    If you don't care to save the op amp, I would just suggest clipping out the IC and sucking the remaining legs out. Not worth potentially damaging components around it. Instead of just pushing out the remaining pin though, what I would suggest is to take flush cutters and cut perpendicular to the flat of the pins right up against the body of the IC. That'll leave you a bit of a leg that you can take a chisel tip of a soldering iron to and just lift the leftover pin out of the through hole. Then you can just use a solder sucker or braid and wick the remaining solder out of the hole. This way will leave you a bunch of room where the original body of the IC was to maneuver the soldering iron tip around.
     
    • Like / Agree Like / Agree x 1
    • List
  5. randytsuch

    randytsuch Facebook Friend

    Joined:
    Oct 13, 2017
    Likes Received:
    195
    Trophy Points:
    43
    Location:
    Los Angeles, Ca
    I agree with ziptrickhead, cut the opamp out, will save a lot of trouble. And there is more potential to damage the pcb if you try to remove the opamp instead of cutting it out. I almost always cut out parts to remove.

    To clear the hole after, I put the board in a board vise, put an iron on one side and solder sucker on the other side. Usually clears the holes quickly. Ground pins may be harder to clear if there is a ground plane, it takes more heat in this case.
     
    • Like / Agree Like / Agree x 3
    • List
  6. joch

    joch Friend

    Friend
    Joined:
    Oct 8, 2015
    Likes Received:
    113
    Trophy Points:
    43
    Location:
    the other side of the ocean
    Thanks guys, I'll stick with snipping off the opamp--think I can afford to lose these at $5/pc. While nice, I probably won't repurpose them (OPA2134), and definitely not worth the risk of mucking up the board or the other components. It's good to get a check on being "penny-wise, but pound-foolish."
     
    • Like / Agree Like / Agree x 1
    • List
  7. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,170
    Trophy Points:
    113
    Location:
    Northwest France
    Man I have trouble with any soldering connected to the ground plane. I manage to get a connection but it doesn't look as clean as my other joints. My current method is to turn-up the iron on max and add a moderate amount of flux before soldering. I also try to use the biggest tip I have so I dont lose too much heat on contact. Probably doesn't help that I'm soldering a 3oz board.

    So any special considerations when soldering ground connections(or other large copper planes)? Do I need to resort to hot air?

    Also have some questions about cleaning boards. I have Chemtonics flux remover which works great removing flux but leaves a white residue behind. 91% isopropyl alcohol does an okay job with most of this, but still leaves behind a thinner layer which Im just going to live with. Whats the procedure to clean up SMD boards with no-clean flux?
     
  8. Riotvan

    Riotvan Got lost for three weeks at Delft City Hall

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    2,654
    Trophy Points:
    113
    Location:
    The Netherlands
    I use Kontakt PCC and then rinse it off with isopropyl, it is nasty stuff though so rinsing is very important. Not sure what the overseas equivalent is.
     
    • Like / Agree Like / Agree x 1
    • List
  9. fishski13

    fishski13 Friend

    Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    393
    Trophy Points:
    63
    Location:
    Twin Cities, MN
    I recently picked up some 99% IPA from Micro Center. It works much better, with less effort, than common 91%. As long as the components are sealed, a light rinse with distilled H2O should be all that's needed for a flux free board.

    For SMD, I've switched to RMA solder, flux, and braid. Tom has a great article on solder and cleaning: https://www.neurochrome.com/choosing-solder/

    I can't say that I've had a lot of issues soldering to a PCB ground. If possible, snipping the leads before soldering will reduce the heat draw. I use a Hakko and a 1.2mm chisel 99% of the time.
     
    • Like / Agree Like / Agree x 1
    • List
  10. Thenewerguy009

    Thenewerguy009 Friend

    Friend
    Joined:
    Oct 11, 2015
    Likes Received:
    399
    Trophy Points:
    63
    Just a beginners question, but when soldering a capacitor to a PCB board, do you place the hot iron tip on the board hole where you want the solder connection to take place. The board gets hot & the solder melts when it comes into contact?

    Or do you place the hot iron tip on the copper wire & let it get hot & then the solder melts when it comes in contact with it in the hole.

    Or do you just melt the solder on the iron tip, close to the hole with the wire in it & let it drip down & make a connection?


    Every tutorial video never shows close ups at an angle where they show the definite way they are doing it. It seems they do all 3 a any given time.
     
  11. Xen

    Xen Friend

    Friend
    Joined:
    Sep 30, 2015
    Likes Received:
    212
    Trophy Points:
    43
    Location:
    Houston, TX
    I had the same issue when building my keyboard. It has a HUGE ground plane and I had major problems with the negative junctions. Then, I calibrated my station and bumped up the temp by 50 C. Everything worked well. I just had to use less dwell time on the positive junction.


    Ideally, you want to add a tiny bit of solder to your iron tip. Then, you want the iron tip (+solder) to touch both the pad (metal part of the hole) and the component leg at the same time. Then, after a small amount of time (depends on iron and technique, about 0.25 seconds for me), you bring in your fresh solder. The fresh solder should melt almost immediately and flow into the hole. Remove your fresh solder, then wait another quarter second and remove your iron.

    Here is a crude illustration of "ideal" technique, where you have plenty of space and the component is not moving and the wind is just right and stuff.

    Soldering Technique.jpg [EDIT] A more "ideal" illustration -> Soldering Technique More Ideal.jpg

    When space is not available or the component is large or many other factors, you adapt. For soldering through-hole components (I'm guessing and not SMD), your 3rd way is the "correct" way.

    Just for fun, here is the poor illustrated version for SMD work. Add solder to 1 pad. Add component, hold in place, bring iron in to melt solder. Remove iron and allow component to set. Solder the other side. Resolder the first side to ensure proper junction.

    Soldering Technique SMD.jpg
     
    • Like / Agree Like / Agree x 1
    • List
    Last edited: Jan 1, 2018
  12. Luckbad

    Luckbad Traded in a unicorn for a Corolla

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    3,451
    Trophy Points:
    113
    Location:
    Laguna Hills, CA
    Home Page:
    @Xen Your illustration makes it look like you should apply fresh solder directly to the tip *when soldering the joint. All I've read/watched about proper soldering technique suggests that you should use the soldering iron to heat the pad and lead, then apply the fresh solder to the the pad/lead away from the tip (I usually do it on the opposite side) to ensure you don't get a cold joint.
     
    • Like / Agree Like / Agree x 2
    • List
    Last edited: Jan 1, 2018
  13. Riotvan

    Riotvan Got lost for three weeks at Delft City Hall

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    2,654
    Trophy Points:
    113
    Location:
    The Netherlands
    A tiny bit helps to conduct heat faster into whatever you want to solder. That's how i was taught at least, never any cold joints.
     
    • Like / Agree Like / Agree x 1
    • List
  14. Priidik

    Priidik MOT: Estelon

    Friend BWC
    Joined:
    Sep 27, 2015
    Likes Received:
    1,824
    Trophy Points:
    93
    Location:
    Estonia
    Proper high end iron solves this.
    One that has temp sensor and heating element right up in tip.
    Cheapest such that I know is the Chinese TS100, modern pro stations also have that kind of tips.
    Turning up your regular iron to have enough power can lead to temp runaway.
    The copper plane can become much hotter than you intended at some point.
    I accidentally melted an IEC socket that was mounted on a board, one time.
     
    • Like / Agree Like / Agree x 1
    • List
  15. Panohm

    Panohm Friend

    Friend
    Joined:
    Nov 14, 2015
    Likes Received:
    198
    Trophy Points:
    43
    Location:
    Vancouver, Canadia
    I'm thinking of picking up a TS100 are there any other small soldering irons/stations to consider? I'd love to get a hakko fx888d but i don't think i'd be able to bring that back from France to Canada. Planning on making iem cables.
     
  16. Xen

    Xen Friend

    Friend
    Joined:
    Sep 30, 2015
    Likes Received:
    212
    Trophy Points:
    43
    Location:
    Houston, TX
    As @Riotvan said, it's to increase thermal load at the tip and helps wick (if using rosin core flux, which you should) the solder onto the joint. The small bit of solder is added to a cleaned tip, just before you want to touch the tip to the component your are soldering. This also decreases dwell time, which is always good for small parts.

    As for the fresh solder, yes, ideally it should be brought in at the other side of the joint away from the tip. For me, it all depends on positioning and in what space I am working in. A forest of leads needs a bit of improvisation unless you are doing it the old NASA way which literally takes over 2 minutes to do 1 solder joint.
    There's another video which has 1 person reading the procedure and while another person demonstrates the soldering. Those are examples of ideal technique!

    The TS100 is very intriguing, but requires a good ~20V power supply. I want one, but trying to figure out whose bundle comes with a decent power supply has been a headache.

    Yes, to heating the copper plane. "Ideally" you work on 2 different planes at the same time to allow one plane to cool. Even a high end solder station will do the same thing because... 0th Law of Thermodynamics - heat flows between two objects until both have the same average internal kinetic energy (Temperature).
     
    • Like / Agree Like / Agree x 3
    • List
  17. Luckbad

    Luckbad Traded in a unicorn for a Corolla

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    3,451
    Trophy Points:
    113
    Location:
    Laguna Hills, CA
    Home Page:
    First part of my post was unclear. I do wet the tip with solder also. I meant to specify that I was only commenting on the joint. Looks like I was just misinterpreting the illustration in any case!
     
  18. bazelio

    bazelio Friend

    Friend
    Joined:
    Nov 16, 2015
    Likes Received:
    3,461
    Trophy Points:
    113
    Hahaha, scrub a dub dub. Yeah that's basically how i was trained eons ago as a college intern at Lockheed Martin.
     
    • Like / Agree Like / Agree x 1
    • List
  19. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,170
    Trophy Points:
    113
    Location:
    Northwest France
    Today i learned if you solder outdoors in the dark, you can see the iron glow red.

    Maybe it was turned up a bit too much....
     
    • Like / Agree Like / Agree x 4
    • List
  20. joch

    joch Friend

    Friend
    Joined:
    Oct 8, 2015
    Likes Received:
    113
    Trophy Points:
    43
    Location:
    the other side of the ocean
    I have a decent basic station but it's stowed away, and use the TS100 more because it's convenient and works quite well.

    As Xen said, a nice power supply is key. SEEED offers a package with a mini brick, whereas if you get it at Banggood the power supply is sold elsewhere in the website. You can find the SEEED version with a power supply occasionally offered on MD.

    You might want to get spare tips (chisel, pointed, etc) at Banggood--it's cheaper there.


    edited: removed unintended image
     
    • Like / Agree Like / Agree x 1
    • List

Share This Page