SMD - Hand Soldering

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Instructables about hand soldering smd by soldering iron
With soldering iron, you can soldering almost smd packages like 0805, 0603, 0402, 0201, 01005, QFP, QFN, PLCC, SOT23, DPAK, ...

Step 1: Materials

- Soldering iron (can adjust temperature 200 ~ 450°C)

- Soldering tip (cut surface 45° or 60°)

- Soldering sponge

- Solder wick

- Tweezers

- Solder Wire (note: lead-free need higher temperature)

- Paste Flux (note: some type use only for lead-free solder)

For easy soldering, i recommend use lead solder (Sn/Pb: 60/40 or 63/37) for low temperature

Step 2: Clean Solder Pads

Clean solder pads for remove oxidized

You can clean with flux or tinning solder pads then remove by solder wick

Step 3: Alignment

Example with QFP100 package

- Put paste flux 2 points at opposite position

- Place chip, use finger or tweezers for alignment fit with solder pads

- Use finger or tweezers for press on top of chip

- Soldering 2 points for fixed chip

Step 4: Soldering

- Put paste flux for all pins on one edge of chip

- Setting temperature for soldering iron
Lead-free solder should 350~400°C, Lead solder should 315°C (±30°) (dependent on size of chip, pins, solder pads, trace width, heatsink ability of chip and pcb)

- Get enough solder on soldering tip

- Touch on first pin, drag to last pin as fast as possible (drag soldering)
or touch on first pin, jump to next pin and continue to last pin (pin to pin soldering)

Step 5: Touch Up

Sometimes the process is not as flawless as desired, like bridges, excess solder or cold solder joints. For solve, use flux and clean soldering tip. When touch up, excess solder will move to soldering tip, or you can use solder wick (not recommend)

Step 6: Clean Flux

For beauty solder joints, need clean flux even with no-clean flux
You can clean flux by alcohol like IPA (isopropyl alcohol) with wiper, cotton wiper, paint brush, toothbrush

Step 7: Videos

Step 8: Lead or Lead Free Solder ?

Video for compare 5 common alloys, maybe helpful for you choose solder type

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    17 Discussions

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    diy_bloke

    9 months ago

    Well done. The smallest smd I think I did was 0603 and yes, fixing it in the right position is half the work

    3 replies
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    RaymondR6diy_bloke

    Reply 9 months ago

    You can add some liquid flux to the chip underside then press and align it on the PCB. The flux will dry and hold the chip in place while soldering. It is cheaper and probably safer then glues.

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    diy_blokeRaymondR6

    Reply 9 months ago

    Tnx. Wasnt too happy with the flux I had...I use solderpaste instead, as that will keep it in place as well. Halogenlamp on it and presto.

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    diy_blokediy_bloke

    Reply 9 months ago

    or just a soldering iron to keep it all 'by hand'

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    DawidW15

    Question 9 months ago

    Yeah, but what about QFN package? Is it really possible to solder without hot air station?

    2 more answers
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    androkavoDawidW15

    Answer 9 months ago

    Sure, for detail you can watch my QFN soldering video at step 7

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    Eric Brouwer

    9 months ago

    Thanks for a very interesting Instructable.
    I really enjoyed the video where you compare the different alloys.

    Regards
    Eric

    1 reply
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    gm280

    9 months ago

    You touch on a few really very important things about soldering. And those things are, make absolutely sure the board runs are clean. We use to use an eraser to clean runs and leads as well. Then clean them with alcohol and let them air dry. Then don't touch any of the runs or part leads. Then tin the runners/pads on the board. Now you can tin the leads or make sure they are clean and ready to solder. Positioning the SMD is key to a quality joint. If you can hold the SMD part, the soldering is a breeze. Good project post with instructions. It takes practice, but isn't hard to do once you grasp the concept.

    1 reply
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    androkavogm280

    Reply 9 months ago

    Thanks you, good information

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    jfryar30272

    9 months ago

    Very cool! I just did a project that required me to solder SMD components like shown here, and this is everything I needed to know to do that! Very impressive!

    1 reply
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    DDW_OR

    Tip 9 months ago on Step 4

    I have 15 years of doing this.
    my preferred tip is a K-tip. it looks big and bulky but it is the only tip i use, even on plastics(with good ventilation)
    https://www.hakko.com/english/tip_selection/series_t12.html#type_k
    https://www.hakko.com/english/tip_selection/type_k.html
    flux, Paste or Liquid
    flux, then use K-tip on top of pins, this draws the solder from the pad onto the pins.
    then use the K-tip on the pad to draw excess solder away from the back side of the pins

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    RaymondR6

    Tip 9 months ago on Introduction

    This is well done and will work for repairing broken off MicroUSB sockets on PCBs. Some soldering tips can be machined or filed to produce that tiny tip. I also recommend using silver based solder as it will conduct better for tiny conductors but needs a hotter temperature to melt.