Soldering ststion selection.

Here's a board I designed and laid out a year or two ago. It's a two axis brushless servo motor controller used for a missile countermeasure system. It employs rigid-flex technology and PWM based motor drive. The boards wrap around the countermeasure head. The two quad flatpack IC's on the right side are TI DSP ICs. The aluminum bracket is a thermal path to the chassis and the perforated area on the right segment is a thermal via array to conduct heat away from a DC/DC converter located on the back side to a sil pad boss on the outer chassis. Resolvers are used for position feedback. It is able to slew a 9 lb inertia 180 degrees in 150 milliseconds with no overshoot. It can deliver up to 1.2 kW operating on 28 VDC/70 VDC supplies. Most discrete SMT components are 0603. The big toriods are part of the output EMI filter. Two of four on each axis have a small secondary winding used to generate a floating MOSFET gate supply for the high side MOSFETs.

I always like to assemble the first circuit card of a new design since I can test it in stages, and also learn where there are potential assembly issues.

The point? This one was hand soldered (no paste) using 0.016 and 0.032 dia 63/37 solder, liquid rosin flux, and a Hakko FX-951.

John

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Nice work, John. I always respect people who can work down to those levels of assembly. A few years ago, my younger brother had the steady hand and good eye to do work at that scale. His profession at the time was camcorder repair, which I'm sure you know is about as compact as it gets. He has since gotten away from the consumer side of things altogether, except for family and close friends. He can't see well enough without cheaters, and really hasn't the patience for it, when he has other work that pays better and is less demanding. He still does commercial video camera work, and people ship from all over to get their cameras repaired....TV stations and the like. He does design and construction of his own products, but tends to avoid micro circuitry when possible.
 
Tony Wells said:
Nice work, John. I always respect people who can work down to those levels of assembly. A few years ago, my younger brother had the steady hand and good eye to do work at that scale. His profession at the time was camcorder repair, which I'm sure you know is about as compact as it gets. He has since gotten away from the consumer side of things altogether, except for family and close friends. He can't see well enough without cheaters, and really hasn't the patience for it, when he has other work that pays better and is less demanding. He still does commercial video camera work, and people ship from all over to get their cameras repaired....TV stations and the like. He does design and construction of his own products, but tends to avoid micro circuitry when possible.
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I hear where you're coming from. 6 or seven years ago, I could solder 0805's and SOICs with my naked eye - not to MIL or NASA spec mind you, but decent commercial (IPC). Now for those, on a good day, I need reading glasses, or better yet a magnifier. T

hat board was assembled under a 25X binocular microscope and was MIL spec.

Nowadays I rely more and more on our assemblers and technicians to build up prototypes. I highlight the parts of the schematic I need built first, the tech highlights the BOM accordingly, and the assembler goes to town. I do still like to assemble my own first article designs when time permits though.

I swear, my eyes got way worse in a very short amount of time after I started wearing reading glasses.

John
 
Dude this is what you got to have

[video]http://revision3.com/tbhs/solderover[/video]
 
Rbeckett said:
Thats a pretty neat approach to doing boards and soldering in the components. I have been studying Prof Axelsons text on creating boards and all of the different ways of doing that. I got that book about a year ago and it it kind of got moved to the side till I started looking into doing this project. I was trying to do as much old school through hole as I could to enhance my understanding and to cement the info into a usable form in my punkin head. Plus I dont see as well as a young man anymore so THC (through hole components) makes it a bit easier to see the component markings for me and my poor eyesight But the skillet method appears to be a neat little trick fer sure. Thanks!!!!
Bob
Click to expand...

Those head mounted magnifiers and a good pair of tweezers are your best friend on small parts. Lots of people use toaster ovens for SMT soldering as well, but I picked up this little electric skillet for about $10 ;)
 
I saw a really nice Hakko set of soldering tweezers that are backwards compatible with the power supplies too. Definately gonna need a good, high quality magnifyer. I started to learn electronics because I wanted to build a Torch Height Controller for my plasma table. What a mess this has become!!!! I have managed to expand a simple design and added a ton of parts selections to support a new goal of "build without waits", let your mind lead the way engineering. Plus I am a card carryin lifetime member of the toolaholic afliction with the addiction bad enough for two normal people too. Since I got older and my kids are grown and gone I have time and more importantly the money to tinker with just about anything that interests me now. I started a three tier brew stand build that I quickly monsterized and kept adding stuff to because I thought it would be a good idea. Funny thing is, I have no kidneys so I cannot partake of the end result. Talk about the great neighbor I have become. I go on these binges and momma just smiles knowingly and pats me on the back. The way I figure it I am still engaged to the rest of the world and possibly helping myself and others with my "investigations". Looks like a found a winner in electronics and machining, w'ell just have to see how it plays out in a year or ten or so. Thanks for the ideas guys, I am still niave so I'm still like a kid in a candy factory about parts and neat tools.
Bob
 
Hey Bob,
do you have anything for the heavier work, like a Weller 550 or similar?

PM me your shipping info, please.
 
Done!!! Thans to Tony Wells for his support of this site and the member on it. Tony is just that kind of stand up guy. He has far and away exceeded the definition of Forum Supporter in many many ways on a daily basis. Lets all get behind him and support his quest to make this site the premier freindliest and most peacefull place to be. I have never been to another site where a member just hooks another member up out of the goodness in his heart. It retores my faith in the general population when things like this happen. They usually happen to other folks, but it is even better when it is your turn. Thanks Tony, youre the man!!!!
Wheelchair Bob
 
Since Tony has taken care of me so well with mentorship and some equipment I have been able to order at least one bin box storage unit for my parts stock. Should be here pretty quick since it's coming from the lower mid west instead of across the pond on the proverbial slow boat from china. Hope to see some improvement in parts storage and project quality soon. Thanks Tony!!!
Bob
 
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