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Will it work :) (first SMD goofball project)

J

James Lerch

Jan 1, 1970
0
Along the lines of "Will it Blend" this one is "Will it Work?"

I'm Putting together an odd ball project for this years Christmass
boat parade. We lovingly call it the spinning wheel of death..

Basicly, something like this, just bigger:

http://hackedgadgets.com/2006/06/13/top-5-spinning-led-displays/


So, to stream line things a little, I put together this Lego block
style display unit which will be driven via Mirco Pic. Here's a link
to the ExpressPCB schematic and board layout

http://lerch.no-ip.com/16-Pixel_rgb_board.zip

What I'm hoping is, someone would find it entertaining to lambast me
on my crap skills, and show me the error of my ways before I commit to
getting a few dozen of these put together. (never built a SMD based
project, never had a PCB boad made for a project, etc., etc. lame
excuse, lame excuse.)


Thanks
--
Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)
http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
 
S

Steve Wolfe

Jan 1, 1970
0
(never built a SMD based
project, never had a PCB boad made for a project, etc., etc. lame
excuse, lame excuse.)

Read the SMD soldering tutorials on www.sparkfun.com, and you won't be so
intimidated by SMD stuff. And after doing your first board, you'll think "I
shouldn't have waited so long to do this."

steve
 
J

James Lerch

Jan 1, 1970
0
Read the SMD soldering tutorials on www.sparkfun.com, and you won't be so
intimidated by SMD stuff. And after doing your first board, you'll think "I
shouldn't have waited so long to do this."

steve

Funny you mention the sparkfun site. I found it on you tube, and
watching him blob solder all over one side of that chip made me
cringe, then he pulled out the de-solder ribbon and I was like "Oh....
neat trick.." :)

I was also surprised just how relatively inexpensive this board turned
out to be. All said done, one board fully populated is going to run
about $25.00. I'll need 4 of them for the proto-type, and another 16
to finish the project if all goes well. The question is am I gutsy
enough to order all 20 up front and hope and pray, or just get 4 and
see if it works....

--
Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)
http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
 
D

Don Klipstein

Jan 1, 1970
0
Funny you mention the sparkfun site. I found it on you tube, and
watching him blob solder all over one side of that chip made me
cringe, then he pulled out the de-solder ribbon and I was like "Oh....
neat trick.." :)

I was also surprised just how relatively inexpensive this board turned
out to be. All said done, one board fully populated is going to run
about $25.00. I'll need 4 of them for the proto-type, and another 16
to finish the project if all goes well.

I developed my own way of soldering SMT parts, especially 0603 size
components:

1. Use tinned fine point tip on low wattage iron to solder one lead/end
of the part onto its pad - even if not well.

2. More properly solder the other end or remaining leads.

3. Solder properly the first connection.

As for getting a really small part such as an 0603 into place to begin
with:

1. Have a good fingernail on your index or middle finger on your
non-iron-holding hand.

2. Dip the fingernail edge into rubber cement.

3. Have the part handy on a convenient surface. Land the tip of your
rubber-cemented-finger (not the nail) near the part, with your
rubber-cemented fingernail tip over the part.

Using the landed fingertip as a pivot, lower your rubber-cemented
fingernail onto the part so that the part sticks onto your fingernail.

4. Similarly land your fingertip in an appropriate location close to
where the part has to go (typically requiring fingertip to land on the
board - ground yourself and board supply rails and the soldering iron if
static-sensitive parts are involved).

Using a fingertip pivoting method as above, lower the part into place.

5. Once the part is located well, tack one lead/end onto the PCB with a
tinned iron as above. Proceed from that point as above.

- Don Klipstein ([email protected])
 
D

Dave Pollum

Jan 1, 1970
0
Along the lines of "Will it Blend" this one is "Will it Work?"

I'm Putting together an odd ball project for this years Christmass
boat parade. We lovingly call it the spinning wheel of death..

Basicly, something like this, just bigger:

http://hackedgadgets.com/2006/06/13/top-5-spinning-led-displays/

So, to stream line things a little, I put together this Lego block
style display unit which will be driven via Mirco Pic. Here's a link
to the ExpressPCB schematic and board layout

http://lerch.no-ip.com/16-Pixel_rgb_board.zip

What I'm hoping is, someone would find it entertaining to lambast me
on my crap skills, and show me the error of my ways before I commit to
getting a few dozen of these put together. (never built a SMD based
project, never had a PCB boad made for a project, etc., etc. lame
excuse, lame excuse.)

Thanks
--
Take Care,
James Lerchhttp://lerch.no-ip.com/atm(My telescope construction,testing, and coating site)http://lerch.no-ip.com/ChangFa_Gen(My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "

James;

I took a brief look at your design. Your board has a lot more parts
than your schematic. Your board's main problem is that vias are both
too close to other vias an also too close to traces. The software let
me place two pads that overlapped each other. This is BAD. And if
there is a menu or command to verify that the board conforms to
ExpressPCB's design rules, I didn't see it. So while the CAD software
is relatively easy to use, it will allow you to make mistakes and
won't tell you about them! I don't know if you can send your board
files to ExpressPCB and have them check it.

I'd suggest using a different CAD program. EAGLE wouldn't be a bad
choice (tho it's a bit quirky), but the problem is that your 1.25" x
12" PCB is too big for the cheap/free version which is limited to a
max size of 4" x 3.2".

Perhaps someone else has some words of wisdom...

-Dave Pollum
 
S

Steve Wolfe

Jan 1, 1970
0
I developed my own way of soldering SMT parts, especially 0603 size
components:

1. Use tinned fine point tip on low wattage iron to solder one lead/end
of the part onto its pad - even if not well.
(snip)

1. Have a good fingernail on your index or middle finger on your
non-iron-holding hand.

2. Dip the fingernail edge into rubber cement.

I put just a *tiny* bit of solder on one pad - even just dragging the
tinned tip of your iron is usually enough. Then I place the part with a
pair of tweezers, and lightly press straight down on it with the tips of the
tweezers to lightly hold it in place. Heat the pad that you tinned, remove
your iron, and bam - it's tacked down, and perfectly placed. Then you can
do the other pads as you wish.

steve
 
J

James Lerch

Jan 1, 1970
0
James;

I took a brief look at your design. Your board has a lot more parts
than your schematic. Your board's main problem is that vias are both
too close to other vias an also too close to traces. The software let
me place two pads that overlapped each other. This is BAD. And if
there is a menu or command to verify that the board conforms to
ExpressPCB's design rules, I didn't see it. So while the CAD software
is relatively easy to use, it will allow you to make mistakes and
won't tell you about them! I don't know if you can send your board
files to ExpressPCB and have them check it.

I'd suggest using a different CAD program. EAGLE wouldn't be a bad
choice (tho it's a bit quirky), but the problem is that your 1.25" x
12" PCB is too big for the cheap/free version which is limited to a
max size of 4" x 3.2".

Perhaps someone else has some words of wisdom...

-Dave Pollum

Thanks Dave,

I was / am worried about the via size and placement. I looked at a
bunch of OEM boards I had laying around and they seem to use similar
setups. (**funny how after doing this one excercise, it interests me
to see how others have done it!! **).

Also, the ExpressPCB program does a little checking when you run the
"Layout / Comput board cost" process. It yelled at me the first few
times complaining exactly about via placement...

BTW, is there a good write up somewhere on "How they do it" ? I'm
guessing they cut and drill a non plated board, then copper plate the
whole board, apply resist, then etch? I'm curious how they
manufacture the plated thru vias...

James

--
Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)
http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
 
D

D from BC

Jan 1, 1970
0
Along the lines of "Will it Blend" this one is "Will it Work?"

I'm Putting together an odd ball project for this years Christmass
boat parade. We lovingly call it the spinning wheel of death..

Basicly, something like this, just bigger:

http://hackedgadgets.com/2006/06/13/top-5-spinning-led-displays/


So, to stream line things a little, I put together this Lego block
style display unit which will be driven via Mirco Pic. Here's a link
to the ExpressPCB schematic and board layout

http://lerch.no-ip.com/16-Pixel_rgb_board.zip

What I'm hoping is, someone would find it entertaining to lambast me
on my crap skills, and show me the error of my ways before I commit to
getting a few dozen of these put together. (never built a SMD based
project, never had a PCB boad made for a project, etc., etc. lame
excuse, lame excuse.)


Thanks

I make about 20 SMD PCB's/year in my kitchen..
But if you want just a few boards then using a PCB fab house will be
my recommendation.


D from BC
 
S

Steve Wolfe

Jan 1, 1970
0
One more bit of advice: Don't worry about packing those SMD devices
tightly. The first SMD board I did was a board with a 555, 4017, darlington
transistors, and associated caps/resistors to sequence strings of LEDs on a
model rocket. When I laid it out, I did it as densely as I thought I could
solder... then nudged them a little closer. Then I thought "Ah... this
board really has to be small. I'll nudge them a little closer." Then I did
that about three more times.

In the end, along with hookups for the LED strings and all, it ended up
being about 1 square inch. And when you look at the thing, it looks
*sparse*. Assembly was no problem, I could have gone tighter still and
been just fine. I stopped where I was because the board had to be large
enough to put an SMT coin-cell holder on the other side. :)

steve
 
M

Meat Plow

Jan 1, 1970
0
One more bit of advice: Don't worry about packing those SMD devices
tightly. The first SMD board I did was a board with a 555, 4017, darlington
transistors, and associated caps/resistors to sequence strings of LEDs on a
model rocket. When I laid it out, I did it as densely as I thought I could
solder... then nudged them a little closer. Then I thought "Ah... this
board really has to be small. I'll nudge them a little closer." Then I did
that about three more times.

In the end, along with hookups for the LED strings and all, it ended up
being about 1 square inch. And when you look at the thing, it looks
*sparse*. Assembly was no problem, I could have gone tighter still and
been just fine. I stopped where I was because the board had to be large
enough to put an SMT coin-cell holder on the other side. :)

steve

When I build SMD boards I always pluck a hair from my head and use it as a
spacer.
 
D

D from BC

Jan 1, 1970
0
When I build SMD boards I always pluck a hair from my head and use it as a
spacer.

MY DIY SMD PCB's are sooooo high density that I made a DIY manual pick
and place vacuum machine.
Tweezers took too much space.
D from BC
 
Y

YD

Jan 1, 1970
0
Late at night, by candle light, [email protected] (Don Klipstein)
penned this immortal opus:
I developed my own way of soldering SMT parts, especially 0603 size
components:

1. Use tinned fine point tip on low wattage iron to solder one lead/end
of the part onto its pad - even if not well.

2. More properly solder the other end or remaining leads.

3. Solder properly the first connection.

As for getting a really small part such as an 0603 into place to begin
with:

1. Have a good fingernail on your index or middle finger on your
non-iron-holding hand.

2. Dip the fingernail edge into rubber cement.

3. Have the part handy on a convenient surface. Land the tip of your
rubber-cemented-finger (not the nail) near the part, with your
rubber-cemented fingernail tip over the part.

Using the landed fingertip as a pivot, lower your rubber-cemented
fingernail onto the part so that the part sticks onto your fingernail.

4. Similarly land your fingertip in an appropriate location close to
where the part has to go (typically requiring fingertip to land on the
board - ground yourself and board supply rails and the soldering iron if
static-sensitive parts are involved).

Using a fingertip pivoting method as above, lower the part into place.

5. Once the part is located well, tack one lead/end onto the PCB with a
tinned iron as above. Proceed from that point as above.

- Don Klipstein ([email protected])

I usually use a toothpick to nudge it into place and hold down. I'll
try rubber cement on the tip, seems like a neat idea.

For lifting I have a piece of aquarium tubing with a filed-off syringe
needle on one end. Place the needle over the part and suck on the
other end of the tube.

- YD.
 
J

James Lerch

Jan 1, 1970
0
Dave,

I carefully read the specifiation from the company, and you are
correct, my via placement was indeed to close to each other and other
traces. What a bummer.

However, I've since re-done the layout a 2nd time and I think I got it
under control this time. Thanks for the heads up!

James
--
Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)
http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
 
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