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32 Comments

  1. Date: February 21, 2018 at 21:38
    Author: scamin sam

    Julian. Noticing down, you have liked only the people who tell you that your great. Trump has the same problem. I would suggest you re read and give some thought to people like me who are trying to tell you something. Many people watch these videos to learn. You are teaching crap. Stick to mail bags and making little flashing LED boards. You have put SMS back 50 years.

  2. Date: February 21, 2018 at 21:52
    Author: tiger12506

    That thick paste is meant for a stencil, but I"m sure you knew that. I'd definitely look into getting a needle tip for that syringe like everyone's suggested.

  3. Date: February 22, 2018 at 07:43
    Author: Greg S

    I always thought one should use sufficient flux when trying to solder surface mount components, has always worked very well for me, I've never had issues with splatter or shorted joints when doing this.

  4. Date: February 22, 2018 at 08:23
    Author: raindogred

    Saw this on hackaday a while back, the guy there used a big halogen lamp that got to 300deg in 5secs…if you were to upgrade your lamp, you are going to need a much more fire retardant base with those temps..probably pine boards or plywood ????

  5. Date: February 22, 2018 at 12:41
    Author: Darth Vader

    While I've never worked with SMDs, I must say that the paste technique precision appears to be akin to a lobotomy with a chainsaw..

    How about this: hold the chip at the ends with tweezers. Apply paste to bottom of chip legs with a cotton bud or toothpick. Then carefully place on the board. Then heat in little oven.

    Worth a try.

  6. Date: February 22, 2018 at 15:21
    Author: Richard Garnish

    If I can offer only one tip that will save you many headaches, it is to buy solder paste from a UK supplier, by next day delivery, and keep it in the fridge. Paste that has spent 6 weeks on a boat and has started to separate will cause no end of trouble, and even paste that looks good but has gone stale will not wet as well, causing bridges, poor joints and other problems like SMT resistors pulling themselves up onto one end when the solder melts.

  7. Date: February 22, 2018 at 18:36
    Author: Infinite loop

    No, sorry Julian… can't watch this. Get some cheap proper SMD tools on AliExpress or Ebay. This is a waste of time, for you and us.

  8. Date: February 22, 2018 at 23:13
    Author: Steve Roberts

    I don't have a hot air gun and have only started smd soldering recently, but I can solder that chip using an iron in less time than it took you to apply the solder paste. It is however an approach I may use for the much smaller chips. I can't justify the cost of professional tools for the occasional very small chip – so many thanks for your video – I will try this in the future.

  9. Date: February 23, 2018 at 07:35
    Author: mdesm2005

    USB scope are pretty cheap these days …. just saying ….

  10. Date: February 23, 2018 at 15:57
    Author: KX36

    I'm glad you're enjoying your experimentation. What's a hobby for if not to have fun eh? But I hope you realise you can solder a SOIC package of 1.27mm pin pitch very nearly as easily and quickly as a through hole component with a soldering iron and some liquid flux and not risk overheating the components. You can even solder TSSOP of 0.65mm pin pitch in this way. Unless you're doing <0.65mm pitch or leadless packages like QFN, there's no point in bothering with solder paste and hot air or reflow ovens, and then you'd probably want a stencil.

    Just put the component in the right place, apply a drop of flux to the area, put a dab of solder onto the end of your iron, hold the component down from above with some tool like tweezers or a wooden stick, slide the iron across the PCB into the end of the component's lead and back out the same way. Tack the corners first then apply more flux and do the rest.

    You don't need to pre-tin the pads or adjust the placement of the component while keeping the solder liquid as many people seem to do, that just makes it harder to get the thing flat on the board. Just don't follow the bad technique of people who blob solder across every pin on one side of the package and then solder-wick it off. That overheats the component and leaves too little solder on the pads in the end. Blobbing across the lot is a desoldering technique.

  11. Date: February 23, 2018 at 21:20
    Author: Maki McLeary

    I use isopropyl alcohol for cleaning and thinning of old / dried out solder paste.

  12. Date: February 24, 2018 at 18:32

    Julian…I might suggest covering the pads only halfway. The solder will flow over the uncovered parts of the pads and it should minimise the "splatter" effect. I actually use 2mm vinyl pin striping tape for this. Using a small tipped natural bristle paint brush seems to work well for me for applying the paste and helps me apply a more even layer. Once the paste is applied I just peel the pin striping tape back, apply the components and heat. I've also found using an automotive headlight bulb (I've got dozens of surplus 9006 bulbs that work perfectly for this) makes for a very quick heating and seems (to me at least) to make for a more directional heat.

  13. Date: February 25, 2018 at 15:32
    Author: aladino10100

    I applied solder paste with a tiny syringe (supplied with solder paste) in a quantity around 50% of what shown in the video and the results were positive soldering with hot air. One important parameter is the solder paste, should be kept in the fridge and brought to ambient temperature a few hours before use. A syringe I used in the past, kept always in my lab (around 20 C) , got completely unusable.

  14. Date: February 26, 2018 at 11:18
    Author: helmut666kohl

    Repeat comment – get blunt dispenser needles, get gel flux, get a 25€ hot air station.
    Or just apply less paste and touch the pads with a regular iron for 2 seconds. Do the 2 opposite corner pins first and hold the IC while soldering, then do the rest. 
    And keep the paste off the soldermask as much as possible, makes life way easier.

  15. Date: February 27, 2018 at 04:12
    Author: Michael Murray

    Another thought….. What would happen if you put the past on the chip first, then put it on the board?????

  16. Date: February 27, 2018 at 07:01
    Author: lucysluckyday

    Great idea. I have a soldering iron, hotair station, and also a reflow oven. Even so, for small boards like this where you have external pins such as QFP then I always prefer using the hot air gun. But if it is QFN, or bigger boards with lots of components then I'll use the oven. It's personally more satisfying using the hotair process so you can watch. BTW, that crackle sound you heard IS the actual moment of reflow, you will hear that with any thermal reflow oven. Leaded and Unleaded both crackle at reflow point.

  17. Date: February 27, 2018 at 14:25
    Author: Astralix2011

    I have seen many successful results using a syringe to put out a mall roll of solder paste over all pads on each side. If you don't have a syringe, you can fake a stencil by putting three lines of kapton tape, that leave two small lines of uncovered pads. Then put a blob of solder paste over the open line and use a sort of spatula to squeeze the paste into something looking evenly applied. Pull the tape, place the chip and off you go.

  18. Date: February 28, 2018 at 15:45
    Author: bridgendesar

    Have you considered using a lens to focus the light, if you got the right type(barrel), you could focus it in a line

  19. Date: March 9, 2018 at 15:09
    Author: ntwwwnt

    Thank you for a really good idea!
    I have a few dozen of these bulbs after changing them to 12V dimmable LED, but didn't have any idea how to use them. Now it's the right time despite I've already have a soldering station with a fan! 🙂

  20. Date: March 10, 2018 at 01:03
    Author: MikeOnTheBox

    If you not going for a perfect application on each pad, why not make a stencil of 2 rectangular areas and apply with it?

  21. Date: April 3, 2018 at 08:25
    Author: Simon Baxter

    Have you not heard of a 'reflow profile'? Its there to ensure 1) The components and board get to the correct temp without mechanical stress before the solder flows, 2) The solder reflows correctly and quickly and 3) everything cools down at a rate which doesnt pull your components apart due to different rates of contraction! You are overthinking the small stuff and not really looking at what reflow requires. Listen to the other posters. You are making yourself look stupid!

  22. Date: May 13, 2018 at 23:30
    Author: pgScorpio

    Julian, another way to do it is to apply the paste to the component instead of to the board. I find it's easier to apply the correct dose that way.

    I apply a thin layer of paste on a piece of plastic and drag the legs through, (any access paste between the legs can be removed with the side of a piece of paper).

    Using a vacuum tool to handle smd ic's is also much easier than tweezers.

    P.S. I just use my solder iron to "reflow" a single component….

  23. Date: May 27, 2018 at 02:33
    Author: cypherf0x

    Or you could have saved yourself a whole lot of time and just learned how to drag solder. SOIC is the easiest to learn on.

  24. Date: September 11, 2018 at 04:14
    Author: pleasecho2

    Dumb question – all that heat doesn't hurt the chip?

  25. Date: October 2, 2018 at 17:26
    Author: Mahla Propyzm

    I would avoid using a cocktail stick. Flux is usually some kind of rosin solution (from pine trees) and will want to adhere to the wood whence it came.
    Perhaps running your flux pen over the pads, letting it dry and using a metal or plastic applicator will persuade the paste to stick where it is needed.

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