Arduino Forum

Using Arduino => General Electronics => Topic started by: Marciokoko on Jan 24, 2016, 01:39 am

Title: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 01:39 am
Wow! One of my first posts here was about trouble I was having soldering header pins onto as lcd board.

I just spent 45 minutes trying to solder thin gauge wire onto the 3 gold pads of a SMD temt6000 light sensor.  No holes to hold anything in place, smaller wire and surrounding plastic, plus my shaky hands!!!

So basically smd components are only used by machines that put them on pcb's, right!?
Title: Re: Smd component soldering
Post by: larryd on Jan 24, 2016, 01:45 am
I often solder SMD parts by hand but, it is getting harder as the years move on.

You may have to lower iron temperature, use liquid flux and use Kapton tape for solder masking.
.
Title: Re: Smd component soldering
Post by: TKall on Jan 24, 2016, 01:49 am
I don't know anything about it but I saw this a while ago and thought I would share it:

http://schmartboard.com/

Welcome to SchmartBoard!

Products: SchmartBoard is the destination for people who want to hand solder surface mount (SMT) components. Are you an engineer, technician, educator, student or DIY hobbyist who has avoided utilizing SMT components? Those days are officially over, because with SchmartBoard practically anyone can hand solder SOIC, QFP, PLCC, QFN,  and discrete surface mount components.
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 02:09 am
Thanks TKall.  I actually do have a pad board but just one and I wanted to save it for a different project.  but ive been thinking, for example there is a Discrete Board from schmartboard, similar to my pad board.  How would I solder a 3 pad device like a transistor?  In holes or pads?

What if the holes or pads are not spaced correctly?

(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151887)

(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151886)
Title: Re: Smd component soldering
Post by: larryd on Jan 24, 2016, 02:32 am
@Marciokoko
Sounds like you have reached the point where you need to look at making your own PCBs.

You should consider physically removing pads that are in the way and not needed.
Do you have a Dremel tool?
 
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 03:01 am
Yes I do
Title: Re: Smd component soldering
Post by: larryd on Jan 24, 2016, 03:04 am
Use the Dremel to grind unwanted foil away, this may help in placing your SMD components.
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Title: Re: Smd component soldering
Post by: madbomb on Jan 24, 2016, 04:16 am
you could try using thinner soldering wire and hold the smd with small piece of blue tack
Title: Re: Smd component soldering
Post by: Grumpy_Mike on Jan 24, 2016, 05:54 am
I use a scalpel to cut strip board. You can cut a slot between the holes to give you 0.05" spacing. You can cut either side of a hole and mount the two connections of a transistor either side with the third spanning the gap to the next track.

I also use bluetack to hold things steady. Also get a good pair of tweezers.
Title: Re: Smd component soldering
Post by: DrAzzy on Jan 24, 2016, 06:55 am
You pretty much need a PCB with the appropriate pattern on it for most SMD work - however beyond that, the actual soldering often isn't that bad.


Breakout boards for specific packages are also reasonably available on ebay and from the usual hobby electronics vendors - the common ones are dirt cheap on ebay - though inevitably you end up with a mess of little boards.

As it happens, I sell some prototyping board that has slots for SMD parts on it, which sounds like it might be just what some people here are looking for: (image is a link)
(http://drazzy.com/e/products/img/AZP-8B_REVB.jpg) (https://www.tindie.com/products/DrAzzy/hybrid-protoboard-2x4-/)


My technique for soldering them I think is pretty standard....

Securely hold board (I use a desk-vise which I can move and rotate easily, but is heavy enough to hold the board still).I put solder on the board, on one pad for each part. Then I go back and tack each part in place on that one pin (tweezers in one hand, iron in other). Then I put flux on all the unsoldered pins. Passives are soldered normally, SOIC/TSSOP/TQFP/etc by drag soldering (youtube it). I frankly prefer soldering SOIC over DIP now.
Title: Re: Smd component soldering
Post by: larryd on Jan 24, 2016, 07:11 am
One thing that might help you is to glue the SMD to the PCB prior to soldering.
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Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 02:59 pm
Great stuff guys.  just a few more questions:

1.  If I buy a board like this, I can't really cut it up to use parts of it, right?  Boards themselves are kind of brittle.  So if I want a board I better be ready to use as much of it as possible or be able to part with unused sections of the board.  On the up-side, they're cheap.

2.  Transistors are a pretty basic 3-legged component.  How come I don't see a lot of specially designed boards with 3-pads in a triangular shape?  Most of what I see are straight line grids of holes and even more sophisticated IC designs.

3.  Larry, thanks, I do have a dremel.  madbomb, I'll see if I can get thinner wire and a pencil soldering iron.  I have 2 irons already, I've gone from a thicker, apparently unremovable tip to a more powerful, fine tip and 2 more tips iron but terribly designed because it's too long and makes it unsteady to hold design.  So at least now I know what to look for.  I'll definitely look for that blue tack as both madbomb and GrumpyMike mentioned.

Title: Re: Smd component soldering
Post by: aarg on Jan 24, 2016, 03:37 pm
I often solder a SOT-23 between 3 adjacent 0.1" spaced proto donuts. It's not a perfect fit, but the solder blobs do make it possible.
Title: Re: Smd component soldering
Post by: Grumpy_Mike on Jan 24, 2016, 04:22 pm
Quote
I can't really cut it up to use parts of it, right?  
No you can cut them up very easily, a saw will do, a fine toothed junior hacksaw or a miniature table saw.
http://www.axminster.co.uk/proxxon-ks-230-saw-300095?gclid=CjwKEAiAiZK1BRD509nPsYiUk2YSJAAMoAwCopplMo3kisiYbccKoQbYQmf91K9MvZ5_o51Z0iPZ-RoC4NDw_wcB (http://www.axminster.co.uk/proxxon-ks-230-saw-300095?gclid=CjwKEAiAiZK1BRD509nPsYiUk2YSJAAMoAwCopplMo3kisiYbccKoQbYQmf91K9MvZ5_o51Z0iPZ-RoC4NDw_wcB)
Then you can mount them on strip board.

(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151962)

Quote
How come I don't see a lot of specially designed boards with 3-pads in a triangular shape?
Because you can simply put then between tracks or pads.
This shows lots of surface mount transistors and resistors on normal strip board.
(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151960)
Title: Re: Smd component soldering
Post by: MarkT on Jan 24, 2016, 05:05 pm
Boards themselves are kind of brittle.
Not if standard FR4.  Pretty tough infact being glass-fibre composite.  Cut with a small hacksaw and expect
to blunt blades fairly rapidly.
Title: Re: Smd component soldering
Post by: Grumpy_Mike on Jan 24, 2016, 05:42 pm
This is the smallest thing I have ever hand soldered. It is a bicoloured LED, with a connection in each corner.
As you can see it mounts between the tracks in strip board.
(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151971)

(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151973)

(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151975)
The lighting up is purely from the current from the resistance setting of a DVM.  
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 06:59 pm
GrumpyMike,

On 9024 image, each track is a long flat copper surface, basically a nice long flat wire?

The rectangles with numbers on them are the resistors whereas the 2-top-left and 2-bottom-left and the 34 top-right and 3-bottom-right slightly longer rectangles are transistors?
Title: Re: Smd component soldering
Post by: larryd on Jan 24, 2016, 07:48 pm
Roadrunner offers a solderable enamel wire for single type, prototyping boards.

This might be something you might want to consider.
http://www.roadrunnerelectronics.com/ (http://www.roadrunnerelectronics.com/)

http://www.roadrunnerelectronics.com/epages/BT3782.sf/en_GB/?ObjectPath=/Shops/BT3782/Categories/Prototyping__Boards (http://www.roadrunnerelectronics.com/epages/BT3782.sf/en_GB/?ObjectPath=/Shops/BT3782/Categories/Prototyping__Boards)

http://www.roadrunnerelectronics.com/epages/BT3782.sf/en_GB/?ObjectPath=/Shops/BT3782/Products/SMT-C-K1 (http://www.roadrunnerelectronics.com/epages/BT3782.sf/en_GB/?ObjectPath=/Shops/BT3782/Products/SMT-C-K1)
.
Title: Re: Smd component soldering
Post by: Grumpy_Mike on Jan 24, 2016, 08:06 pm
On 9024 image, each track is a long flat copper surface, basically a nice long flat wire?
I think you mean the other one.
Yes strip board has tracks with holes every 0.1".

Here is the diagram I made it from, I hope you can relate the two.
(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151987)
Title: Re: Smd component soldering
Post by: larryd on Jan 24, 2016, 08:09 pm
Mike, what program did you use for the image/design in the above post?
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Title: Re: Smd component soldering
Post by: Grumpy_Mike on Jan 24, 2016, 08:20 pm
Roadrunner offers a solderable enamel wire for single type, prototyping boards.
Verowire is an almost identical system and there is a lot of stuff if you search for it.

I use it with surface mount resistors and capacitors, as shown here.
(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=151989)

Quote
what program did you use for the image/design in the above post?
It is called MacDraft, it is just a general purpose 2D drawing package.
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 08:31 pm
Wow!  I'm going crazy taking apart old stuff.
Now that I know what they are.  I wish I would have kept the optocoupler from an old Wall wart I threw away a few days ago.

Title: Re: Smd component soldering
Post by: larryd on Jan 24, 2016, 09:04 pm
Quote
It is called MacDraf

Thank you.
Title: Re: Smd component soldering
Post by: Boardburner2 on Jan 24, 2016, 09:13 pm
Great stuff guys.  just a few more questions:

1.  If I buy a board like this, I can't really cut it up to use parts of it, right?  Boards themselves are kind of brittle.



Strip board is normally paper phenolic, it is brittle, but pad board can be had in epoxy which is not, but difficult to cut.

I use a board shear which is easy but they are costly.
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 09:28 pm
I'm trying to post images of what I have.


What are those 2 ICs of which one is labeled U2?  This is a small pcb from a battery-solar panel combination:
(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=152004)

TL431 seems to be a shunt regulator.  I thought this was a transistor at first because they look like a transistor.  But I have been noticing that lots of things look like transistors :-)
(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=152002)


These black rectangles without letters are the transistors, right?  Is there any way to find out what kind they are?  I guess for R its just a matter of reading the letters on top of them:
(http://forum.arduino.cc/index.php?action=dlattach;topic=374124.0;attach=152000)
Title: Re: Smd component soldering
Post by: Boardburner2 on Jan 24, 2016, 09:54 pm
Quite possibly, its fairly common to see small smd without marking as there is not much room.

Even ic's can have no markings or have no traceable no's on the net.

If you need transistors they are cheap and not worth salvaging generally.

If you are a beginner though , nothing wrong with trying to identify components.


TL431 seems to be a shunt regulator. 

Its a precision voltage reference
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 10:42 pm
Well the optocoupler would've been cool!
Title: Re: Smd component soldering
Post by: Boardburner2 on Jan 24, 2016, 11:12 pm
TL431

Being through hole that's definitely salvageable and useful.

Sm generally not so much.
Small components are generally very cheap.
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 11:42 pm
GrumpyMike, so in post #18, when a rail connects two components and you want to use the rest of the rail for something else, you strip off the copper?  Is that what the greyed out square shapes are?

Title: Re: Smd component soldering
Post by: Marciokoko on Jan 24, 2016, 11:47 pm
From post #24, what could those 2 small ICS be?
Title: Re: Smd component soldering
Post by: Grumpy_Mike on Jan 24, 2016, 11:58 pm
GrumpyMike, so in post #18, when a rail connects two components and you want to use the rest of the rail for something else, you strip off the copper?  Is that what the greyed out square shapes are?
Yes they are breaks in the copper. Look at the previous photo to see them. I make them using a scalpel, rest it on the side of the hole and make a small nick. Then turn the board over and make a nick on the other side of the hole and the copper between the two nicks is removed. Repeat this for the copper on the other side of the hole for a minimum break that could be left or bridged by a surface mount component like a resistor.

I did this video to illustrate how to solder a surface mount light sensor:-
https://vimeo.com/138562025 (https://vimeo.com/138562025)
For this project:-
https://vimeo.com/142866214 (https://vimeo.com/142866214)
But it is not an Arduino project.
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 25, 2016, 12:11 am
You make it look so easy.  How thick is the tip of your iron?  I measured mine at 1mm.
Title: Re: Smd component soldering
Post by: Boardburner2 on Jan 25, 2016, 12:50 am
You make it look so easy.  How thick is the tip of your iron?  I measured mine at 1mm.
There is a tool for breaking the tracks, basically an 1/8 in drill in a handle.

If your bit is small it may not get heat in fast enough especially if its a long thin one.

Bit selection can make a difference with small stuff.

Strip board can adsorb quite a lot of heat, more so than a PCB.

Title: Re: Smd component soldering
Post by: larryd on Jan 25, 2016, 01:08 am
FYI
https://www.youtube.com/watch?v=i5MNLTc7YhY&app=desktop (https://www.youtube.com/watch?v=i5MNLTc7YhY&app=desktop)
Title: Re: Smd component soldering
Post by: larryd on Jan 25, 2016, 02:10 am
Quote
There is a tool for breaking the tracks, basically an 1/8 in drill in a handle.
http://sg.rs-online.com/web/p/stripboard-cutters/0543535/ (http://sg.rs-online.com/web/p/stripboard-cutters/0543535/)
Title: Re: Smd component soldering
Post by: Boardburner2 on Jan 25, 2016, 02:35 am
That's the one , mine cost 2 quid though.

About 20 yrs ago and still works.
Title: Re: Smd component soldering
Post by: larryd on Jan 25, 2016, 04:28 am
This might stir the pot:
https://aa7ee.wordpress.com/tag/wbr-regen/ (https://aa7ee.wordpress.com/tag/wbr-regen/)

(https://i2.wp.com/www.pbase.com/daverichards/image/136603883/original.jpg)

Also

(http://i0.wp.com/cdn.makezine.com/uploads/2012/10/newimage.png)
.
Title: Re: Smd component soldering
Post by: Marciokoko on Jan 25, 2016, 08:03 pm
Cool...makes me want to post my acrylic board with super glued wire :-)
Title: Re: Smd component soldering
Post by: Grumpy_Mike on Jan 26, 2016, 12:38 pm
You make it look so easy.  How thick is the tip of your iron?  I measured mine at 1mm.
That one started life at 0.8mm
http://uk.farnell.com/weller/pt-p8/tip-conical-0-8mm/dp/416708 (http://uk.farnell.com/weller/pt-p8/tip-conical-0-8mm/dp/416708)

There is a tool for breaking the tracks, basically an 1/8 in drill in a handle.
True, sometimes called a spot face cutter.
However there are two problems with it:-
1) They often leave a very thin, almost invisible to see without magnification, strip of copper on one side.
2) They produce a gap which is too big to span with a surface mount resistor.

Quote
f your bit is small it may not get heat in fast enough especially if its a long thin one.
That depends entirely on the iron behind it. The Wella I use is a curie point magnetically controlled 40W iron, so it does not over heat and can supply all the heat you need into a copper strip despite the shape being long and thin.

@LarryD - Very nice construction there.