Looking for tips or does and don't on Micro soldering

[Jam]

I'm going to replace some micro parts and I was hoping to get some tips. These parts are so small thanks for any info

[nickb]

What parts exactly?

For things like 1206 down to 0603 I use a magnifying lamp. First apply a tiny amount of solder and some flux (or solder paste if you have it) on to the pads, put the part in place and then use two fine tipped soldering irons to flow the solder. I never got on with those tweezer type irons. For 0402 and 0201 you need a stereo microscope and a large dose of care & patience.

For leaded chips I tack use tacky flux to help position it , then solder a couple of the leads on opposite sides to hold it in place and then do all the rest of the leads with a fine tipped iron and thin solder - I think I have something like 0.4mm or 0.3mm dia.

For leadless you need a hot air station. Tin the pads or better carefully apply solder paste using a stencil. Be careful not to have the air flow up so high that it blows the part of the board. It can help a lot to have a background heat applied to the underside.

It takes some practice.

[olddawg]

As was said. You need a clean uncluttered area to work (if something pops off you need to find it). You need bright light and magnification. I've used a lighted magnifier, a binocular microscope, even a video camera. Many times under magnification you can see the issue is not a bad component but a bad connection. You need liquid flux. Use solder braid to remove as much solder as possible with flux. Sometimes low temp solder like ChipQuick can really be helpful. Be aware that microprocessors are often glued to the board. In that case, cutting all of the leads with an exacto knife, unsoldering and removing one leg at a time and then knocking the chip off the board is a better option. Clean the entire area with solvent after a component is removed to start fresh with your reinstall. Hot air is very helpful. I've fixed a lot of stuff using just flux and my Hako with a single nozzle. If working with cmos you need an antistatic mat and a grounded wrist strap. Don't ground yourself like that for anything powered up! If it's a ball solder array surface mount device don't expect to do much unless you have the lab oven available to do it.

[Jam]

I'm doing micro Op amp could a use a regular solder iron?

[olddawg]

I'm doing micro Op amp could a use a regular solder iron?

If it has leads a small wedge tip should be fine. Flux the leads and absorb the solder with some solder braid/wick. A sharp pointed probe is helpful. Just take your time and don't lift the pads. ChipQuick makes it easier. It's not for the ham handed. I recommend practicing on junk boards.

[Mick Bailey]

+1 on Chip Quik. makes removal really easy. Get the component off the board then clean up the pads as per instructions/Youtube videos. For replacement, I tin one corner pad with a little solder and position the replacement IC along with a tiny amount of SMD rework flux. Using a probe, I lightly hold the IC in position and then heat the leg. The flux improves thermal coupling and also helps the solder to flow. So I now have the IC held by one leg. After checking alignment and making any necessary adjustments, I solder the opposite diagonal leg, then finish soldering the rest of the pins. I use fine rework solder (27G tin/lead/silver) that has a 2% silver content and lower melting point. It flows really well and the flux prevents bridging between component legs. I use my regular wedge iron tip that I use for everything else. A clean up with alcohol and it's done. Much quicker in practice than how this reads.

For me, magnification is essential. For really small stuff I have a couple of binocular inspection microscopes, but usually I get a long fine with my illuminated bench magnifier.