SMD components for a hobbyist

  • Thread starter Dmitri(Cabling-Design.com
  • Start date
D

Dmitri(Cabling-Design.com

Guest
Hello everybody!

I feel that I have to tell you: this is a great group, and I have real
pleasure reading posts here. This community seems very supportive and
extremely knowledgeable. Keep up good work!

Here is a question I wanted to bring respectfully to the group's attention:

Long story short: 15+ years ago I worked in electronics industry, being
involved into anything from PCB assembly to business ownership and
anything in between. 15 years and couple careers later I look back at the
electronics as a great hobby I would like to get back into.

Anyways, it seems that SMD components have grown to dominate the market
and suppliers' parts lists, and in majority of cases are mighty cheaper
that their through-hole counterparts. Besides, having no drilling in PCBs
somehow makes me feel that it would be easier to master homebrewed PCBs
(for parts with reasonable spaces between the leads, nothing
nano-tech-ish). With that said, I have realized that I would need to
completely re-tool in order to be able to do any SMD handling. My old
soldering iron seems too big, even multimeter probes don't seem to cut it
anymore for SMD.

What would you suggest as a reasonable set of brick-and-mortar SMD tools?
Something I would use for 90% of SMD work, something like my trusty iron,
tweezers and snips would do for through-hole? I see ads for hot air rework
stations, never used one of them, are they any good/relatively easy to
master? Are they of any use if I initially populate a PCB instead of
actually re-working it? BTW, I already got that vacuum pickup tool, I
would guess it will have to replace my tweezers. Still, how do you
(conveniently?) pickup or hold something like 1206-type SMD resistor or
SOT-23 part?

And, I think the biggest question is: should I even bother messing around
with SMD components on a hobbyist level?

Thank you all responded!

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------


##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.basics - 5582 messages and counting!
##-----------------------------------------------##
 
On Tue, 09 Nov 2004 23:09:12 GMT,
info_at_cabling-design_dot_com@foo.com (Dmitri(Cabling-Design.com))
wrote:

Hello everybody!

I feel that I have to tell you: this is a great group, and I have real
pleasure reading posts here. This community seems very supportive and
extremely knowledgeable. Keep up good work!

Here is a question I wanted to bring respectfully to the group's attention:

Long story short: 15+ years ago I worked in electronics industry, being
involved into anything from PCB assembly to business ownership and
anything in between. 15 years and couple careers later I look back at the
electronics as a great hobby I would like to get back into.

Anyways, it seems that SMD components have grown to dominate the market
and suppliers' parts lists, and in majority of cases are mighty cheaper
that their through-hole counterparts. Besides, having no drilling in PCBs
somehow makes me feel that it would be easier to master homebrewed PCBs
(for parts with reasonable spaces between the leads, nothing
nano-tech-ish). With that said, I have realized that I would need to
completely re-tool in order to be able to do any SMD handling. My old
soldering iron seems too big, even multimeter probes don't seem to cut it
anymore for SMD.

What would you suggest as a reasonable set of brick-and-mortar SMD tools?
Click to expand...
Small-tip iron, skinny solder, solder wick, tweezers, and good light
and optics! Liquid rosin flux is sometimes handy, too.

Something I would use for 90% of SMD work, something like my trusty iron,
tweezers and snips would do for through-hole? I see ads for hot air rework
stations, never used one of them, are they any good/relatively easy to
master?
Click to expand...
Overkill, quirky, not really needed. Mostly just blows the parts away.

Are they of any use if I initially populate a PCB instead of
actually re-working it? BTW, I already got that vacuum pickup tool, I
would guess it will have to replace my tweezers. Still, how do you
(conveniently?) pickup or hold something like 1206-type SMD resistor or
SOT-23 part?
Click to expand...
Small, sharp-point tweezers are fine for big parts like this. I like
the stainless ones with the curvy ends. I was just replacing an 0805
and remember thinking what a big part it seemed; 1206's are getting
rare these days, so skip them unless you really need the power
dissipation.

And, I think the biggest question is: should I even bother messing around
with SMD components on a hobbyist level?
Click to expand...
Sure, just do it. It's not actually hard... just takes a little
practice.


John
 
John Larkin wrote:
Small, sharp-point tweezers are fine for big parts like this. I like
the stainless ones with the curvy ends. I was just replacing an 0805
and remember thinking what a big part it seemed; 1206's are getting
rare these days, so skip them unless you really need the power
dissipation.
John
Click to expand...
Hi John,

Thank you for the insight! Do you think it may be practical to mount a
small SMD part with some sort or semi-permanent clay-like glue (I forgot
how they call it in the craft store) BEFORE actually soldering? I have a
great interest in LEDs and all sorts of display technologies. So, the SMD
LEDs are basically a piece or epoxy resin with metal contacts on the
sides. How do they hold the heat while soldering? I guess, what I'm trying
to say is: when you solder, the epoxy becomes softer, but this is the only
place you can hold with the tweezers. So, chances are you can squeeze too
hard and damage every other LED. Any tips you can give on soldering an SMD
LEDs?


--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------




##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.basics - 5603 messages and counting!
##-----------------------------------------------##
 
Roger Johansson wrote:

Yes, they are actually more convenient in many ways. No need for
drilling, for example.

I do protype boards and simple projects by taking a piece of pcb board,
use a sharp file or similar tool to make grooves in it, dividing the
copper layer into different parts, nodes, rubbing it with scotch-brite
kitchen pad to clean off the oxide, and then solder smd components
between these islands of copper.
Click to expand...
Thanks, Roger, I appreciate your suggestions!

I totally agree with you on the drilling, having no holes is a great plus.
There is only one problem, however: the holes are also a great way to
neatly align the components. Having no holes means you no longer have any
point of reference on the PCB. As you correctly pointed out, most of the
time the PCB is just going to sit inside the box, so that would not
matter. However, I'm going to try to attempt to solder SMD LEDs in a
rather orderly fashion, a pattern rather, and I'm going to need alignment
big times. Is it a no-no in a manual SMD PCB soldering to make it look
neat or there is some technique I'm not aware of that can help?


--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------



##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.basics - 5605 messages and counting!
##-----------------------------------------------##
 
On Wed, 10 Nov 2004 03:02:42 GMT,
info_at_cabling-design_dot_com@foo.com (Dmitri(Cabling-Design.com))
wrote:

John Larkin wrote:
Small, sharp-point tweezers are fine for big parts like this. I like
the stainless ones with the curvy ends. I was just replacing an 0805
and remember thinking what a big part it seemed; 1206's are getting
rare these days, so skip them unless you really need the power
dissipation.
John

Hi John,

Thank you for the insight! Do you think it may be practical to mount a
small SMD part with some sort or semi-permanent clay-like glue (I forgot
how they call it in the craft store) BEFORE actually soldering? I have a
great interest in LEDs and all sorts of display technologies. So, the SMD
LEDs are basically a piece or epoxy resin with metal contacts on the
sides. How do they hold the heat while soldering? I guess, what I'm trying
to say is: when you solder, the epoxy becomes softer, but this is the only
place you can hold with the tweezers. So, chances are you can squeeze too
hard and damage every other LED. Any tips you can give on soldering an SMD
LEDs?
Click to expand...

I did use some tiny edge-emitting surfmount LEDs a while back. They
were OK for solder paste/reflow oven production, but if you tried to
mount one with tweezers and an iron, it would melt in the tweezers
like a tiny marshmallow. 0805-type (ceramic substrate) LEDs seem OK,
but I think the clear epoxy they use on the SOT-23 and similar types
melts easier than the black epoxy used on regular ICs. SOT-23 LEDs
fail a lot if soldered by hand.

If you're doing quantities, solder paste the pads (syringe or better
yet stencil), goosh down the parts, and reflow in an oven. Or buy a
ceramic-base part.

John
 
info_at_cabling-design_dot_com@foo.com (Dmitri(Cabling-Design.com))
wrote:

I totally agree with you on the drilling, having no holes is a great
plus. There is only one problem, however: the holes are also a great
way to neatly align the components. Having no holes means you no longer
have any point of reference on the PCB. As you correctly pointed out,
most of the time the PCB is just going to sit inside the box, so that
would not matter. However, I'm going to try to attempt to solder SMD
LEDs in a rather orderly fashion, a pattern rather, and I'm going to
need alignment big times. Is it a no-no in a manual SMD PCB soldering
to make it look neat or there is some technique I'm not aware of that
can help?
Click to expand...
If you create a straight pattern to solder them to, like a straight
groove and solder them bridging that groove they will be neatly lined up.

For even more precision clamp a straight object to the pcb and push the
leds against it while soldering one side. That will ensure that they are
accurately lined up in a straight line. Another object, very small,
between two leds while positioning will help keep the same distance
between them.

These are common tricks in woodworking, only applied at a miniature
scale.

All smd component can stand the heat from a small soldering iron for a
few seconds. If that time is not enough let it cool down completely
before making a new try.

With some training you can solder small joints fast and with precision.

The real challenge are smd chips with lots of pins very close to each
other. For that you need to design and etch a pattern, and solder it by
dragging a drop of solder along the row of pins. If the temperature and
the size of the drop is good enough it will leave exactly the amount of
solder needed at each pin.
The surface tension of molten solder makes this method work.

The temperature at the tip of the soldering iron is important to get
right in all soldering, but even more important when working with smd
components.
It has to be hot enough to make the solder quickly flow like mercury, yet
not too hot so the components are damaged.
Keep the copper islands or tracks small/thin so they do not need too much
heat and time to solder.
Big copper areas cool down the solder and make it much more difficult.


--
Roger J.
 
In doing mostly repair of SMD boards, I have found a few tools useful:

Fine-tip variable heat solder iron: Xytronic 258 (about $25 from MCM or
Electronix Express) Get the finest point tips.

Tweezer iron with tips of several widths: Xytronic 236 (about $60 from
Electronix Express) I use this with a variable autotransformer or a light
dimmer.

Pinpoint heat gun HeJet HJ500S (about $150 from MCM) This one is also very
useful for through-hole. Just be carefull not to blow off parts you don't
want to remove!

I have also found it very helpful to have liquid rosin flux in a needlepoint
dispenser bottle for use while soldering. Then clean it off with acetone or
alcohol.

Neil


"Dmitri(Cabling-Design.com)" <info_at_cabling-design_dot_com@foo.com> wrote
in message news:s6ckd.2675344$yk.422506@news.easynews.com...
Hello everybody!

I feel that I have to tell you: this is a great group, and I have real
pleasure reading posts here. This community seems very supportive and
extremely knowledgeable. Keep up good work!

Here is a question I wanted to bring respectfully to the group's
attention:

Long story short: 15+ years ago I worked in electronics industry, being
involved into anything from PCB assembly to business ownership and
anything in between. 15 years and couple careers later I look back at the
electronics as a great hobby I would like to get back into.

Anyways, it seems that SMD components have grown to dominate the market
and suppliers' parts lists, and in majority of cases are mighty cheaper
that their through-hole counterparts. Besides, having no drilling in PCBs
somehow makes me feel that it would be easier to master homebrewed PCBs
(for parts with reasonable spaces between the leads, nothing
nano-tech-ish). With that said, I have realized that I would need to
completely re-tool in order to be able to do any SMD handling. My old
soldering iron seems too big, even multimeter probes don't seem to cut it
anymore for SMD.

What would you suggest as a reasonable set of brick-and-mortar SMD tools?
Something I would use for 90% of SMD work, something like my trusty iron,
tweezers and snips would do for through-hole? I see ads for hot air rework
stations, never used one of them, are they any good/relatively easy to
master? Are they of any use if I initially populate a PCB instead of
actually re-working it? BTW, I already got that vacuum pickup tool, I
would guess it will have to replace my tweezers. Still, how do you
(conveniently?) pickup or hold something like 1206-type SMD resistor or
SOT-23 part?

And, I think the biggest question is: should I even bother messing around
with SMD components on a hobbyist level?

Thank you all responded!

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------


##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.basics - 5582 messages and counting!
##-----------------------------------------------##
Click to expand...
 
On Wed, 10 Nov 2004 14:57:23 GMT,
info_at_cabling-design_dot_com@foo.com (Dmitri(Cabling-Design.com))
wrote:

Steve Evans wrote:


Do yourself a favor and buy a few dozen SMD capacitors or resistors at
the same time. They're great to practice the technique with and it
doesn't matter if you damage them since they're *so* cheap. When your
confidence is gained, go on to the LEDs.

Good point!

I knew quick soldering will be a problem at first, so I got myself ceramic
body 1206-type LEDs for starters.

Where do you stock up on discrete SMD components, anyways? They are rather
chap on eBay but the problem is variety: I don't really need 10,000 of the
same type on a tape, I may hardly use 100 in a year or so. What's the best
strategy to procure the small amounts?
Click to expand...
Sample kits. Mouser, Digikey, Garrett.

John
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top