Smd component soldering

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!?

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.
.

I don't know anything about it but I saw this a while ago and thought I would share it:

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.

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?

padboard2.png

padboard1.png

@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?

Yes I do

Use the Dremel to grind unwanted foil away, this may help in placing your SMD components.
.

you could try using thinner soldering wire and hold the smd with small piece of blue tack

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.

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)

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.

One thing that might help you is to glue the SMD to the PCB prior to soldering.
.

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.

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.

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.

Then you can mount them on strip board.

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.

Marciokoko:
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.

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.


The lighting up is purely from the current from the resistance setting of a DVM.

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?

Roadrunner offers a solderable enamel wire for single type, prototyping boards.

This might be something you might want to consider.

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
.

Marciokoko:
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.

Mike, what program did you use for the image/design in the above post?
.