Soldering

[Inspectorgadget]

Hello, first time poster.  Thanks for giving room for me to ask questions with this forum. 

I am just learning to solder components.  I am soldering a resistor 0201 size.  My question is how to test if my soldering job is sufficient so that the resistor is doing it's job.  So for example, if the resistor looks like it's solderer, I want to know 100% that I did it right.  Is there a way to test with multimeter?  If so, what is the steps to do so.....thanks for your time!

[CatalinaWOW]

You are unlikely to find anything less than gross faults with a multimeter.  A visual inspection under magnification is probably your best bet.  A quick Google for SMD solder inspection criteria will get you descriptions and pictures of what to look for.

[sleemanj]

I am just learning to solder components.  I am soldering a resistor 0201 size.

0201 is very small for you to "learn to solder components".  Most people would call it quits with hand soldering at 0402.

[wraper]

A good microscope for inspection. With multimeter you need some test points other than terminals of the resistor itself. Moreover, the fact it measures properly at the moment, does not guarantee there is a good solder joint.

[nanofrog]

Hopefully the NASA Workmanship Standards: Pictorial Reference site should be of some help (covers more than just soldering). 

[Inspectorgadget]

Thank you all for your replies.  I will inspect it and pray it works!

[CatalinaWOW]

After more thought I think some more explanation is necessary, along with a slight retraction.

A multimeter can detect shorts, opens and CHANGES IN VALUE.  It cannot detect lack of wetting, insufficient solder fill, cold solder and a variety of other faults which may lead to non-functioning after a few power or temperature cycles.

Hand soldering of tiny components puts you at great risk of overheating the component.  They are relatively robust, but can change value under enough duress.  A multimeter can be used to find this fault, and probably should be in your case if there is danger that an incorrect value could result in damage to other parts of your device.

[aries1470]

You may not want to begin with 0201. 0805 is a good start, then you can try 0603. Any smaller should really be done with hot air or oven, unless you pay a lot of money on super fine chisel tips, and these ultra fine ones die quickly.

I do 0402 so often that on my boards there are usually only 0402 passives, besides power capacitors. But I use hot air.

Thank you for your reply.

I was considering using "hot air" and was looking at something along the lines of these:

TENMA  21-10130 UK+EU  Rework Station, 500 °C, 220 V

would this be suitable for soldering SMD with the hot air? Would this tip be suitable?

NOZZLE, SINGLE, 4.4MM I take it that I can use this and run along the edges of a device (I.C.'s) ?

What nozzles do you recommend and everyone else's opinion counts, as I am transitioning from a toaster oven, and wanting to do away with the "pre-baking" of parts that are moisture sensitive not that I used it often, but I want to learn new skills and... I just liked the feeling of soldering, so I want to get some control back too. 

So any help would be greatly appreciated.

If I need to start a new thread, I am more than happy for an admin to create a new thread for this post of mine.
So... would this work station be adequate for low volume production, like a few pcb's a day? prototyping mostly before I take the plunge for outsourcing, or low volume as I have mentioned already...

Oh yeah, the packes I will mostly be dealing with would be the following:

• Soic,
• DIP? I wonder if it would work, hmm...
• QFN / TQFN
• DFN
• Sot-25
• MSOP
• TSSOP
• TSOT

And one last question, how do you "solder" the "ground plane" / "Exposed Pad" for since plenty of these devices now have the pad at the bottom, do I just put paste and warm it from the underneath? How will I know it has melted?

Thanks in advance.

[nanofrog]

I was considering using "hot air" and was looking at something along the lines of these:

TENMA  21-10130 UK+EU  Rework Station, 500 °C, 220 V

would this be suitable for soldering SMD with the hot air? Would this tip be suitable?

FWIW, Tenma is a brand name owned by Farnell that they seem to fulfill with products from the lowest bidder (my experience at any rate).

I'm not a fan of the all-in-one stations of this caliber either, as when one breaks the entire unit is down. Separates also offers you the ability to have a better quality iron than hot air, as it's used a lot more often. This is even true for SMD (think drag soldering; if it's got legs coming out of it or pads up the edge, you can solder it with an iron).

Hot air in general would do what you want, and you don't need a bunch of different nozzles.

NOZZLE, SINGLE, 4.4MM I take it that I can use this and run along the edges of a device (I.C.'s) ?

Yes.

As per sizes & shapes, I just use the 3 round nozzles that came in the box (6.4mm, 8.4mm, & 12.7mm). Thin sheet metal, such as heavy aluminum foil used to make disposable bakeware (just needs to be easy to form), works wonders for shielding surrounding areas from hot air if that's an issue. 

So... would this work station be adequate for low volume production, like a few pcb's a day? prototyping mostly before I take the plunge for outsourcing, or low volume as I have mentioned already...

I'd be a little concerned with that particular unit, but a decent one, Yes.

• DIP? I wonder if it would work, hmm...

Yes, particularly for desoldering.

And one last question, how do you "solder" the "ground plane" / "Exposed Pad" for since plenty of these devices now have the pad at the bottom, do I just put paste and warm it from the underneath? How will I know it has melted?

Paste is certainly one way to do it. Pre-tinning the pads with an iron & adding liquid or paste flux to the pads prior to placing the chip is another (this method won't leave un-melted solder balls). The biggest trick IME with SMD is to use plenty of flux (iron or hot air).

Assuming you're not aware, do yourself a favor and use quality name brand consumables rather than unknown brands (solder wire, solder paste, flux, even desolder braid/wick as you still need this to clean up pads).

If you can make the chip dance/rock on the pads, then the solder underneath the chip has melted (this does assume the airflow is set properly <i.e. decent flow rate, but won't blow the part off the board>).

[aries1470]

I can not say for sure if a particular model will work for you or not. What I can tell you is, my Quick 957DW hot air gun and Weller WES51 soldering iron work perfectly for my uses.
Any, they are cheaper. I got them from Adafruit and Amazon, respectively, for totally $180 plus tax and shipping, somewhere like $220 total.
Plus, you need a pair of fairly well built tweezers, I use ideal-tek SS.SA, but some may prefer more blunt or even flat tips. Anyway, a good pair of tweezers usually run at least $20.
Finally, you need flux (I have a tacky one with higher activity, and a water soluble one for general use) and solder paste. I recommend to start with SnBiAg low melt paste melting at 138C, as your skill improves, you can try SnPb solder (probably illegal in the EU), which melts at 183C. Eventually as you master the art of handling delicate and heat sensitive parts, you can try SAC (Sn-Ag-Cu) lead free solder paste.
You also need a pair of eagle eyes, or a magnifying glass, which I have both. A high brightness desk lamp or flashlight with mount will make things much better. Do not waste your money on Mantis (debatable) or any USB solutions, as Mantis has quite some distortion at side view, and USB microscope is simply impractical -- the delay drives me nuts.

Thanks for the info. 
As for the ALPHA CVP-520, it is suitable with Lead-Free only components, not a mix :-( not to mention very hard to find here.
At least from the normal local suppliers.
So I will need to be checking the components everytime. I live in Austrlia, and can't remember anything about the "Lead-Free" only thing, normal SnPb is widely available.
"All components used with ALPHA CVP-520 must be lead-free to eliminate the formation of tin/lead/bismuth intermetallic which has a melting point under 100ºC."

The price point comes to about the same, as the AUD is less than the US, and the Quick 957DW is not made anymore. Either way, it comes with a soldering iron with it :-)

Are the tips the same for "all" hot air guns" / "Reflow Stations"? and would the one that I included a link to be a useful one?

Soory for the "noob" questions   

[aries1470]

Thank you  nanofrog and blueskull for the pearls of wisdom you have parted with.

I was looking at the Tenma due to pricing as im on a very tight budget since i'm on a pension.

The most i can afford is about  $250 Aud. Sorry for not mentioning my budget constraints.
I am located in Melbourne, s.e. subourbs.
There was also a Jaycar one, but discontinued(?) But without any images.

I am open to suggestions.  I have access to Farnell/ element 14, rs-components, altronics and rockby, while mektronics is priced out of my budget

Again, thank you to both dor your tips on how to better prepare myself for the hot air adventures :-)

Sent from my smartphone. SGS7E.

[nanofrog]

I was looking at the Tenma due to pricing as im on a very tight budget since i'm on a pension.

The most i can afford is about  $250 Aud. Sorry for not mentioning my budget constraints.

I have access to Farnell/ element 14, rs-components, altronics and rockby, while mektronics is priced out of my budget

Do you currently have an iron, or do you actually need that as well?

Given your budget limitations, needing both will put some pressure on your budget, but it's actually doable (i.e. Hakko FX-888D iron + 858D hot air station). Quality of the hot air station is a major compromise of course (Dave did a teardown & review of one), but it's under $100AUD shipped. Ideally, I'd say go for used quality gear, but I couldn't find any on eBay.com.au, nor could I locate a Quick distributor in Australia (they've become my go-to recommendation for new, yet with decent quality and a price tag that's far easier to swallow than Hakko or better <paid $225 shipped for my 861DW>).

If you only need hot air, then you can try and do a bit better, but the choices are limited (checked the sites you mentioned; stuff I'd have wanted to recommend were out of budget). So you'll be stuck to brand names such as Tenma, Aoyue, ATTEN, and Yihua, which aren't known for top-notch quality (some are slightly better than others however). Hobbyists are usually forced to compromise on hot air stations due to cost, but since you can use the iron for the vast majority of tasks, the hot air station won't get nearly as much use, so you can usually get away with it. Same with a pre-heater, should you find you need one sometime down the road.

If you happen to find a source for Quick stations in Australia however, it would be worth your time to investigate IMHO (i.e. 861DS or 861DA & use the appropriate plug adapter as both are 220V versions; EU & UK plugs respectively). Ordering from the EU or UK is out of your budget, unless you can wait a bit longer (i.e. 225 - 235GBP + shipping, which is likely going to come in ~$450 - 480AUD to your door ).

[aries1470]

Thank you Nanofrog for posting that, I found this in a link on that page from the suggested related items
3in1-Soldering-Iron-Rework-Station-Hot-Air-Gun-DC-Power-Supply or Same thing, different seller but will most likely go with this one, as it is a "Yihua" and the LED's seem slightly better. On the other hand, I have found some 2in1 like this one. They are also close to me (Nunawading is only about a 30 minute drive, or 1 hour with the bus if I won't drive up to that location), so I will check about their "melbourne warehouse"... if they have it in stock, available for pick up, I will get this, else I will go for the 3 in 1 Yihua, although there are a couple of different models for the power supply, others even have a "USB outlet and 2A power supply instead of 1A.

I guess these are a better "bargain" than the Farnell/ Element14 one. I get to save plenty of $$ too :-) thanks again for opening up many other options.

As for a soldering iron, I do have a couple, but nothing to write home about  So I guess with this unit, I will still have left over $$ to get a seperate iron if it turns out to be a total dud. 
The best one I have, has turned out to be a battey operated one sold by Jaycar when they were a new line, (I seen some youtube reviews of similar units that were excellent, so I am considering on modifying it to work from a USB adapter), that is better than my other ones, think of "Tandy/ Radio Shack", and the other with a base unit was a knock off 'hacko" one. Works ok, but the screw ring, that keeps the tip secure ended up being slightly short so it can not catch a groove properly  so the tip ends up falling out every now and then.

Many thanks for showing me other items too :-) Now I have plenty to choose from 

[nanofrog]

I guess these are a better "bargain" than the Farnell/ Element14 one. I get to save plenty of $$ too :-) thanks again for opening up many other options.

You're welcome. 

That said however, I'd still recommend you go for a hot air only unit. I say this, as the irons tend to be underwhelming performers, and have been known to get too hot to hold as well. And I wouldn't trust the PSU with a barge pole. So at least going for a hot air only unit will save you some funds you can put to better use elsewhere, such as saving up for a better iron, components, ....

[KL27x]

would this be suitable for soldering SMD with the hot air? Would this tip be suitable?

•Soic,
•DIP? I wonder if it would work, hmm...
•QFN / TQFN
•DFN
•Sot-25
•MSOP
•TSSOP
•TSOT

The only thing on that list that needs hot air is QFN/TQFN, DFN. Anything with external leads, sans a thermal pad in the center, is (more, dare I say?) easily soldered with an iron. Including 0201 resistors.

My preference for ICs is external gull wing pins, and (with microscope) the finer the pitch, the better. Larger pitch/pins just takes more solder (thus more time).

Hot air station is essential if you want to use DFN/QFN though. So you will probably end up with one, anyway. That said, I use my hot air very rarely. Unlike with the leaded packages, the smaller you go with hot air/oven reflow, the more pain in the ass it is to use these parts.

In my limited experience, this also translates to assembly services. With at least some providers, the tiny leadless parts will increase the cost and/or failure rate.

Also, if you have any excess boards leftover, leadless parts are pretty close to useless to salvage unless very expensive/rare, due to the handling/cleanup. If you have enough expensive leaded parts to justify salvaging them, they can be easily reused, pretty much after just a dunk in acetone. Well, unless you used a no-clean flux that turns to white gunk.

[JuKu]

Wow. I've done soldering more than 30 years, and I still consider 0402 as my absolute lower limit. I'm getting old, but I have never managed 0201s by hand, mo matter what equipment.

[aries1470]

Wow, you guys are super special 
I can only manage 0805 and 0603 and the occasional sot-23 3 pin... even though I am only 45y/o (my pension is a DSP, due to other ailments), I am starting to get the occassional "tremor", doc said, "Oh it's nothing, if it gets more frequent, then you will know you are at the early stages of Parkinsons"... So, umm, it comes on after about 5 mins doc of trying to solder, "You are trying to hard, find something else to do, that does not require fine precision, and tension, try to relax". What the, Electronics is my hobby since a young kid doing a couple of projects for fun, and now I am trying to make something of it, "don't stress yourself, try and to occupy yourself with other things", but this relaxes me, "do you have any other hobbies?"... well, let's say he didn't make my day, after that, all I was hearing from him was 

Yep, that is why I have come to this lovely place to inquire, so I can look at solutions while I still can 

Cheers guys and thank you for the follow up.