Soldering small

Today I putzed with making suitable drive electronics for my summertime bug-free yellow LED reading light mentioned here before:
http://members.goldengate.net/dforeman/yellowlight /
Being retired and somewhat incorrigable, today became more of a "wonder if I can" rather than goal-directed activity making any rational sense. I don't have to make sense. I'm retired!
I have 150 pcs of LM358 opamp in the mini SO-8 package in my goodiebox so I wondered if I could solder leads to one.
I did. http://members.goldengate.net/dforeman/yellow_lite_elex /
The wire is #30AWG wire wrap wire, .010" dia. I gobbed some 5-minute epoxy on afterwards to add some robustness.
Guess I'm still ahead of the DT's and Parkinson's. Knock on wood!
The current regulator, comprised of this opamp, three resistors and a MOSFET, will be a "bulge in the cord" of a surplus switcher wallwart (as suggested by Spehro) that I found at Electronic Goldmine for the $2.99 or so that Spehro mentioned. I'll house it in a bit of plastic water pipe (ABS?) already turned down to about .034" wall thickness. It's about 5/8" ID. I discovered by experiment today that this stuff easily handles 80 degC, relevant because the goo I plan to use to pot the elex in the tube needs 80C to cure in less than a lifetime. My CBCR (cord bulge current regulator) doesn't really need to be potted, but I may as well use this really good 3M Scotchcast resin before it turns to rock from old age. I'm amazed that it hasn't already done so.
Maybe more later on this.
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Looks awesome and good idea to use a unique color.
The smallest soldering for me happened when I was fixing my son's MP3 player. It would not power up.
I took the player apart and found the issue (which was not obvious prior to taking it apart). What broke was the on/off switch. It was soldered and fell off due to inadequate support.
Soldering it back on was a challenge for me, but it did work out.
i

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On Sat, 13 Feb 2010 23:34:02 -0600, Don Foreman wrote:

...
...
That looks like it will work fine, but for your other SO-8 packages, note that that the 0.050" lead spacing of SO-8 matches the 0.050 card edge pin spacing on PCI cards. If you have any old PCI interface cards sitting around, you can cut off sections of card edge to use as PCB's for making prototypes. (Of course, if not in a hurry, you can have a real $13 PCB made via <http://www.batchpcb.com .)
--
jiw

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On 2/13/2010 10:38 PM, James Waldby wrote:

"$8.00/sq. in. for 4 layer designs"
Bless you, James!
--Winston
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wrote:

I didn't know about those guys. Thanks!
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Nice job! I know I've lost a lot of my ability to do really small stuff. I did solder some cracked surface mount ICs on a Dell laptop, a well documented problem. Now I've accumulated a bunch of optics and mechanical helpers for fine work. I really like my $50 200 power zoom lighted still/video microscope!
I'm contemplating a fix for a Toshiba laptop video card that has ball array mounted memory chips that need repair...no replacement cards available. I'll build a dam on each chip and fill it with molten lead from my lead pot. What do I make the dam from? What temp should the lead be to fix the array yet not fry the chips?
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Do you have a link to your $50 200 power zoom lighted still/video microscope!
Mike
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There's millions of them on ebay.
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Buerste wrote:

Like this: USB, 10 - 200x, 1.3Mpixel, $57? http://tinyurl.com/yglupmz This one is 1/2 the resolution & twice the price (lots of example pix): http://tinyurl.com/yausz59
How does one go about choosing one?
Thanks for awakening me to the existence of a new toy ... er, tool, Bob
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I am not sure of the temp, but in the industry hot air is used to apply or reflow those, and a fixture holds the chip up off the circuit board so that it's weight does not squish all the solder balls into one massive solder short. Duration of heat application is also critical, to not get either cold solder or overcooked, this is all done with a huge machine with special fixtures for each board and chip used, copper chills on the back, computer timed and regulated airflow, and to move the chip that last mm into contact at the exact right moment. If it was made with lead-free solder, it is even fussier about process parameters. I'd suggest finding another video card on eBay except I suspect any other card made at about the same time will show similar issues. I don't think BGAs (ball grid arrays) have the same lifespan as QFPs, etc. Still, I think I'd try a used pull before I tried to reflow a BGA without the machine... --Glenn Lyford
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On Sun, 14 Feb 2010 04:42:16 -0800 (PST), Glenn Lyford

Then again, some work can be done with a syringe full of soldering mixture and a toaster oven... and you don't even need to align the parts all that carefully.
http://www.youtube.com/watch?v=_5lksMvmqQc
-- Terry
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Nice soldering. The macro picture makes it look easy. I zoomed out to actual size* & it was much more impressive. What kind/size of iron & solder? Any special technique?
Nice picture, too. Any special technique for it?
Keep up the good work, Bob
* - using the FireFox "Image Zoom" plug in.
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Don, you sure have a steady hand. Did you use a microscope to see those 0.050" spaced pads?
If I tried that, I'd have two big solderballs.
Tell us your technique please.
Wes
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Those aren't spaced .050. This is a mini-SO8 with pins spaced .026" on centers. Gaps between pins are about 0.015". I use a Meiji binocular zoom microscope set at about 5X magnification.

Reported in another post a few minutes ago. With the right tools, it's really not as tricky as it may seem. They are: a microscope and the Pace soldering station. http://www.happcontrols.com/tools/92144600.htm
Ah! The tip is 1124-0003-P1 http://www.happcontrols.com/tools/92144700.htm
The guy that showed me how to work with surfacemount stuff uses the Pace Heatwise station. Same iron, no digital readout. http://www.happcontrols.com/tools/92144500.htm
His optical aid is a Mantis, really cool but not found on EBay in nearly the plenty that good binoc microscopes are, or were when I was looking anyway. http://www.visioneng.com/elite_overview.php

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Don Foreman wrote:

I do way too much of this stuff myself. I often make prototypes by supergluing the part upside down to bare copper pcb laminate then soldering the wires. Little bits of double stick foam tape work well for positioning the wires.
Good luck on the BGA. I've never been able to successfully attach wires to one. Let us know if you get it to work.
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Don Foreman writes:

Is this real? It always seemed like a phony gimmick to sell light bulbs. The incandescent color filtering can't have been high Q enough to affect insects, just a slight effect to impress the rubes. LEDs would be another matter.
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On Sun, 14 Feb 2010 15:32:22 -0600, Richard J Kinch

The next word in my post after "bug-free yellow" that you excerpted was "LED". I'm using an amber 2.5-watt Luxeon LED. It really is ignored by bugs. I'm replacing one I made 2 years ago that disappeared last summer so I'm not hypothesizing here. It works, at the lake, in Minnesota.
In addition to being quite narrow spectrum, it also runs cool and emits about no IR.
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I *thought* mosquitoes could sense infrared but my quick read of wiki didn't mention it. A general google search finds a lot of add copy selling things mentioning mosquitoes and IR but that sure isn't authoritative. ;)
Remember waking up one night on a back packing trip with my dog to the sounds of most of the Michigan air force (mosquitoes) circling around my little back pack tent. They found us some how. We were not emitting light.
What type of bugs are you hoping won't be attracted?
Wes
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Wes wrote:

Maybe CO2. I the UK midges are quite prevalent in Scotland, while not mozzies, they bite and are known to home in on CO2 sources, such as humans and other animals, very effectively. Maybe also how you smell, an ex girlfriend could be bitten repeatedly in the night and I might get one bite if I was unfortunate and I was next to her.
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Wes wrote:

They can sense infrared and CO2. You didn't have a chance.
--

Richard Lamb
http://www.home.earthlink.net/~cavelamb /
  Click to see the full signature.
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