# Common SMD size

M

#### Michael

Jan 1, 1970
0
What is the most common (of the larger) SMD sizes for resistors, caps and
the like?

The style number is what I'm after.

Larger the better, for me and unsteady hands but don't want something being
phased out either.

Thanks.

J

#### John Popelish

Jan 1, 1970
0
Michael said:
What is the most common (of the larger) SMD sizes for resistors, caps and
the like?

The style number is what I'm after.

Larger the better, for me and unsteady hands but don't want something being
phased out either.

Thanks.
The sizes are the length and width in hundredths of an inch. The
largest common size is probably 1206 (12 hundredths long by 6
hundredths wide or .12 by .06 inch). But there are lots more parts
values available in 0805 size. Unless overall size is at a premium, I
normally use 0805 instead of smaller sizes, just because the pick and
place tolerances are less of a problem. The yield is essentially
100%. They are also lots easier to hand rework than the smaller sizes.

J

#### Joerg

Jan 1, 1970
0
Hello Michael,

Besides the 1206 and 0805 that John mentioned there is also MINI-MELF.
They are round which can be good and bad. I kind of like them because
you can loosen the tweezer grip a wee bit, roll them onto the pads, tack
one side and then solder.

Regards, Joerg

S

#### Spehro Pefhany

Jan 1, 1970
0
What is the most common (of the larger) SMD sizes for resistors, caps and
the like?

The style number is what I'm after.

0402 or 0603. Don't worry about the tinier ones for a while.
Larger the better, for me and unsteady hands but don't want something being
phased out either.

Then use 0805. You'll still be able to buy them, in a fairly full
range, but a bit more expensive.

Best regards,
Spehro Pefhany

P

#### Pooh Bear

Jan 1, 1970
0
Spehro said:
0402 or 0603. Don't worry about the tinier ones for a while.

You forgot the wink ! ;-)
Then use 0805. You'll still be able to buy them, in a fairly full
range, but a bit more expensive.

Don't forget to buy some tweezers. And whatever you do, don't sneeze whilst
placing them !

Graham

J

#### John Devereux

Jan 1, 1970
0
Joerg said:
Hello Michael,

Besides the 1206 and 0805 that John mentioned there is also
MINI-MELF. They are round which can be good and bad. I kind of like
them because you can loosen the tweezer grip a wee bit, roll them onto
the pads, tack one side and then solder.

I bought some of those when I was starting SMT prototyping, mainly
because they still have the colour bands for value marking.

I hate them! They roll around everywhere and my tweezers wont hold
them properly for some reason. I can't read the colours anyway (even
with magnification), they look wrong somehow.

I use standard 0805 now, much nicer.

J

#### John Larkin

Jan 1, 1970
0
What is the most common (of the larger) SMD sizes for resistors, caps and
the like?

The style number is what I'm after.

Larger the better, for me and unsteady hands but don't want something being
phased out either.

Thanks.

Like the other guys, I think 0805 is a good choice. Get some decent
lighting and magnification... even 1.75x drugstore reading glasses
work pretty well with 0805's. SMD is *not* difficult.

John

P

#### Phil Hobbs

Jan 1, 1970
0
John said:
Like the other guys, I think 0805 is a good choice. Get some decent
lighting and magnification... even 1.75x drugstore reading glasses
work pretty well with 0805's. SMD is *not* difficult.

It isn't hard if you're using a board. It took me awhile to learn how
to do do reliable dead-bug style prototypes with SMTs, but it's possible.

And for hacking around, it's much easier to stand the 0805s up like
billboards instead of flat. It looks ugly, but the tweezers never slip,
and you can get the iron into the tightest-packed places that way.
Prototype SMT boards usually die by having pads cooked off them(*), and
the billboard trick speeds up soldering significantly.

Cheers,

Phil Hobbs

(*) Various s.e.d denizens have recommended using one via per pad, to
reduce this problem, but I dunno--that's a lotta vias.

R

#### Rich Grise

Jan 1, 1970
0
You forgot the wink ! ;-)

Don't forget to buy some tweezers. And whatever you do, don't sneeze
whilst placing them !

Graham

Do parts that little have any kind of markings, with any rhyme or
reason? Or do you just have to remember which bin you picked it
out of?

Never mind, some do, some don't. I got out my 5X illuminated magnifier,
that look like coarse-ground black pepper, and a couple of them had
"103" without the quotes printed on them, so they're probably resistors.
They're about 0.08" x 0.05". =:-O lessee - there's a couple caps: Nope,
they just looked bigger because they're pinkish beige, rather than black.
Ooh! There's a big'un! No markings, but it's about 0.12" x 0.06". Oh,
there it is, "L4" is screened next to it. ;-)

Sheesh! Not my cup o' tea, thanks - I guess I'll go the FPGA route and
let somebody else solder the stuff down. ;-P

Cheers!
Rich

J

#### John Devereux

Jan 1, 1970
0
Phil Hobbs said:
It isn't hard if you're using a board. It took me awhile to learn how
to do do reliable dead-bug style prototypes with SMTs, but it's
possible.

And for hacking around, it's much easier to stand the 0805s up like
billboards instead of flat. It looks ugly, but the tweezers never
slip, and you can get the iron into the tightest-packed places that
way. Prototype SMT boards usually die by having pads cooked off
them(*), and the billboard trick speeds up soldering significantly.

One great thing about SMT is that all my prototyping stock fits into a
single small box of envelopes, which goes on the bench in front of
me. I have a wall full of plastic drawers for the through hole stuff
(which I rarely touch),

J

#### Joerg

Jan 1, 1970
0
Hello John,
Like the other guys, I think 0805 is a good choice. Get some decent
lighting and magnification... even 1.75x drugstore reading glasses
work pretty well with 0805's. ...

Once I passed 40 I realized that I needed 3x drugstore glasses for that.
Bought them more by accident, tried them on, and "ahhhh". It's also
safer to solder with glasses in case an electrolytic decides to put on a
pyrotechnic show.

SMD is *not* difficult.
Sometimes I find that it is even easier than thru-hole. No more turning
around of the board. But it sure is a drag getting older while all the
stuff shrinks to less than 0402.

Regards, Joerg

J

#### Jim Thompson

Jan 1, 1970
0
Hello John,

Once I passed 40 I realized that I needed 3x drugstore glasses for that.
Bought them more by accident, tried them on, and "ahhhh". It's also
safer to solder with glasses in case an electrolytic decides to put on a
pyrotechnic show.

SMD is *not* difficult.

Sometimes I find that it is even easier than thru-hole. No more turning
around of the board. But it sure is a drag getting older while all the
stuff shrinks to less than 0402.

Regards, Joerg

But you're still just a baby ;-) ... I'm just weeks away from 66 :-(

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

Global Warming is God's gift to the Blue States ;-)

M

#### Michael

Jan 1, 1970
0
0805's it is then although It looks like searching digi key that 1206 is

I think I'll stick with the larger for resistors, only because I shake like
Don Knotts anymore.

Is that the case with most popular cap values as well?

Is 1206 just as available as 0805 in caps?

I did some 0805 today but those 0603 would drive me nuts.

I've just been placing with some scotch tape and tacking one side under an

J

#### John Larkin

Jan 1, 1970
0
It isn't hard if you're using a board. It took me awhile to learn how
to do do reliable dead-bug style prototypes with SMTs, but it's possible.

And for hacking around, it's much easier to stand the 0805s up like
billboards instead of flat. It looks ugly, but the tweezers never slip,
and you can get the iron into the tightest-packed places that way.
Prototype SMT boards usually die by having pads cooked off them(*), and
the billboard trick speeds up soldering significantly.

I seem to break the parts a lot if I stand them up. The end caps come
off.

These snap-apart boards are slick for small protos and test circuits:

http://www.beldynsys.com/singledual.htm

I just snap them apart and attach them here and there to a piece of
copperclad with hot-melt glue. Solder on a few SMB connectors and
bigger parts, and wire it up.

For anything more serious, lots of people, like AP Circuits, will do a
small batch of 2-side plated-thru boards for $60 roughly. John J #### John Popelish Jan 1, 1970 0 Rich said: Do parts that little have any kind of markings, with any rhyme or reason? Or do you just have to remember which bin you picked it out of? Forget capacitors. But all the 0805 resistors I use have the resistor code printed on them (white on black), even the 1% ones. And I am near sighted enough to read them without additional magnification. S #### Spehro Pefhany Jan 1, 1970 0 0805's it is then although It looks like searching digi key that 1206 is readily available for 1/4w resistors. Check out 0.1% resistors, for example. And compare the price of typical bypass or C0G capacitors in 1206 vs. 0805. or 0603. OTOH, 0402 tend to come in reels of 10K, which is double that of I think I'll stick with the larger for resistors, only because I shake like Don Knotts anymore. Is that the case with most popular cap values as well? Is 1206 just as available as 0805 in caps? I think their stock is biased towards the older parts, compared to Asian production stock, but here's Digikey's stock situation: Capacitors size # of different parts 1206 1336 0805 1798 0603 1976 0402 1432 0201 716 Resistors Thick film Thin film 1206 6364 127 0805 6375 1420 0603 5167 1219 0402 2585 268 0201 252 29 I did some 0805 today but those 0603 would drive me nuts. 0805 is very comfortable to deal with. I still find 0402 a bit tiny and tend to lose a few in solder blobs or ejected into space from the carrier tape. But okay for a prototype or two-- the last one I did had 75 or so 0402 caps and resistors per board, though I needed a shot of single-malt by the time it was done. I've just been placing with some scotch tape and tacking one side under an overhead magnifier. Best regards, Spehro Pefhany K #### Keith Williams Jan 1, 1970 0 To-Email- said: But you're still just a baby ;-) ... I'm just weeks away from 66 :-( I'm right in the middle. ;-) I don't normally wear glasses, but have a pair of +1.75s for close work. Anything stronger and I get nauseous. I'm looking for a pair of +1.00 or +1.25s for computer work but the drug and dollar stores never seem to have ones bigger than my displays. I like tiny fonts on large screens. ;-) S #### Spehro Pefhany Jan 1, 1970 0 I'm right in the middle. ;-) I don't normally wear glasses, but have a pair of +1.75s for close work. Anything stronger and I get nauseous. I'm looking for a pair of +1.00 or +1.25s for computer work but the drug and dollar stores never seem to have ones bigger than my displays. I like tiny fonts on large screens. ;-) Drug and dollar stores? Why don't you go to a proper optometrist and optician (ophthalmologist wouldn't hurt either at your age, he or she will check for glaucoma), lay down a few Franklins, and get some nice purpose-made optical wear. Your eyes will thank you. Best regards, Spehro Pefhany P #### Phil Hobbs Jan 1, 1970 0 John said: I seem to break the parts a lot if I stand them up. The end caps come off. Pure brute force, tsk tsk. Of course, for someone who puts 48V forward bias on a diode, what can one expect? These snap-apart boards are slick for small protos and test circuits: http://www.beldynsys.com/singledual.htm Those are cute, thanks. I'll have to order some. But once I have the SMTs on there, I'll have to restrain myself from attaching them to the board upside-down with Krazy Glue. For anything more serious, lots of people, like AP Circuits, will do a small batch of 2-side plated-thru boards for$60 roughly.

Yah, I know I can get that done...but I have way too many rocks to push
to do my own PCB designs too, alas.

Cheers,

Phil HObbs

J

#### John Larkin

Jan 1, 1970
0
Pure brute force, tsk tsk. Of course, for someone who puts 48V forward
bias on a diode, what can one expect?

I knew I should have been a lumberjack.

Those are cute, thanks. I'll have to order some. But once I have the
SMTs on there, I'll have to restrain myself from attaching them to the
board upside-down with Krazy Glue.

Tsk tsk. It's sad what years of sniffing Krazy Glue can do to a fine
mind.

John

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