Solder paste requires contact between the two parts being soldered. It works great for soldering new chips to a new PCB. For everything else, solder usually works better.
Some 7135 chips arrived from fastTech today, and I decided to give it a go. I knew it wouldn't be as smooth going as in relics easy as 123 tutorial, so I was mentally prepared. First problems encountered:
#1- I can't see.
#2- looking through a magnifying glass really messes up your coordination.- no go
#3- I still can't see
#4- holding chip in place with left hand and tweezers is hard.
#5- I still can't see.
I finally did a little fluxing, got the chip in place, and basically took a blind stab at the rear tab with a glob of solder...hoping that when I blinked the chip wouldn't end up all wee-waw. The blob grabbed, and the chip is now attached, and lined up pretty good. I went for the "no bend" method. Besides not being able to see, and hoping for the best, I lined up the solder, lowered the tip, shoved the solder at it, and pulled the tip up...blindly. Well, after squinting and scrutinizing and magnifying, it seemed to have worked. I repeated the process on the other leg, and decided that if I also went for the middle leg, I would screw it all up. I was thinking of doing another chip, but I couldn't figure out how, without screwing up the chip beside it. Anyway, I did it. I'm sure next time might be easier.
Now to clean up the aftermath. I couldn't have done this without my Sunwayman Torpedo shining some light on the subject.
Next Question. If I wanted to add two chips to a board, could I stack both on top of the same chip? It seems to me it would be easier to solder two together first, and then solder them onto the one on the board.
Thanks relic, and everyone who threw in. It wasn't pretty, but, I did it.
Nice job there, thank you for scaring me through and through! Now I know what not to do because if I try it freehand I’ll blow the board or fry it or something for sure. So it occured to me, if holding it in place to solder is one of the biggest challenges, could you just use some thermal adhesive and glue it on first? Then come back and make the connections? Is there a team of Electrical Engineer Army Ants that can go in there and build a joint like trusses under a bridge? I’ll pay em, or give em cake, whatever they prefer!
If it’d work to stack 2 then solder it on, would the solder that holds the first 2 together melt when you tried to tie it to the one on the board?
Could a guy set up a macro lens on an HD camera and send the video to a monitor and use the live feed on a large monitor as the eyes, like a doctor, and maneuver through a larger playing field? No sneezes or coughing allowed. Probably best to lock the kid out, huh? When you’re in there up-close-and-personal, how do you keep from breathing the solder smoke, which I presume comes from the flux? Need to set up a fan first?
Ouchyfoot, feels good doesn’t it! How many are you going to put on? Shooting for the legendary 40? Is 4 actually reasonable for a first timer? Or is that biting off a big chunk?
What if I bought a new Weller station, one of the cheap ones…like $35 with a screwdriver style blade tip? I think 30 watt or 50 watt, would that work? My pencil iron is very old and I don’t think it’s EVER been cleaned, or properly tinned for that matter. I just knocked off a bunch of black scale from the shaft the other day, what’s that all about?
Maybe I should just give my redneck neighbor a couple of beers to weld them on with his torch….
That picture… COOL. its like you have small little workers at job there. I picture them as live toys from a Pixar movie or something.
Nice job on the 7135 chip!
I need help. Looking at soldering stations there’s a couple kazillion of them out there. How do I know what to get? I don’t know the names and certainly not the models, so will someone please look at these 3 and give me a heads up?
That first one has caught my eye, but the Saike looks very very capable as well. Have no idea though, they could all be junk.
Thanks in advance for any tips from anybody that’s in the know on this stuff.
I didn't look at your links, but I posted this one from MCM a little while ago (still on sale and US shipping). See posts 20 and 22.
-Garry
X-Tronic one is a Hakko clone. Usually good.
The second one is a full station, with hot air. interesting… Edit: This looks good, but overkill for soldering driver chips. Unless you want to spend $100+ on an iron, the HK or MCM option makes the most sense. I may give this a try though. It’s Hakko compatible iron with hot air rework… The genuine models of these are in the $600 range.
I do not recognize the third one.
The one from the Bunkster 
is probably the best deal for US delivery. The HobbyKing one is in stock. not sure if the MCM one still has the deal on, but Tenma is a good brand of Hakko clone.
Heres a Link for the Hobbyking model.
Amazon.com doesn’t ship those stations to Canada, and I can’t find anything reasonably close for that price on Amazon.ca
Anyway, Ouchyfoot, congrats on a job well done! looking good.
As for stacking three high; it can be done, but I wonder about heat buildup in such a small area. You could put two on one side and two on the other side for four extra, 12 total.
You have a Weller station; nice.
I like Weller, used to have them at work. I have a Hakko 936 here, which I like too. I never used a clone but they get good reports from others.
Thanks relic. I've only built one light so far. I tried a P60 first, and trashed the whole thing. My $7.50 iron could hardly melt solder. I almost gave up. I decided, "I want this hobby", so I bought the Weller. With zero soldering experience, my first build came out perfect. I think I could paint a portrait in solder with this station. My only regret is that I wasted $7.50 on the first one.
Im looking forward to your "How to use copper braid" tutorial.
If anyone could do a tutorial on how to pot a driver, I wouldn't mind.
Hey! How'd you know my nickname? (Although I haven't gone by that nickname in years!)
-Garry
Ok, I broke down and got this one http://www.amazon.com/Hakko-FX888-FX-888-Soldering-Station/dp/B004M3U0VU
What finally got me was remembering all those times my soldering totally sucked rotten eggs. Hopefully that’s fixing to change.
You’ll like it. Having control of your heat makes a huge difference. I was looking at that one too. The reason I went with Weller was the availability of parts and service in Canada. Hakko isn’t very prevalent here. The Weller Canada facility is just down the street from where I work.
But it was just too high. The Hakko at $83 with free shipping made it work. And wouldn’t you know, right after I ordered it I found the Digital model with readout for $7 more! Aaagghh. lol That’s ok, this one will be Way better than anything I’ve ever used before. I also got a 1.2mm bevel tip for it.
The Weller was like $123 + $18 shipping, hate it when the shipping makes it a no-go.
I will probably get the station and the AMC7135’s about the same time, should already have the new drivers if all goes well. They could all come on the same day and I’d be happy! 
What do you use the bevel tips for?
That small bevel tip will work beautifully for dragging the solder up to the legs of the stacked chip, relic style. Or so I’m hoping!
Hmm, I wasn’t aware of that. I guess that’s because I buy tips online. I’ve had my 936 so long I do not even remember where I got it. I’m due for an upgrade/second station… a hot air rework station would be really nice for what I typically do.
I found a Canadian seller with the YiHua 853D with tons of accessories for C$130 + tax (local seller) shipped. Pulling the trigger…
Pretty cool station. Video review:
Edit: added tax, forgot I will have to pay that because the seller is in my province. $147 now…
Wow. That’s way over the top for someone with my meager needs. I sure hope you didn’t get caught up in our purchasing chit chat, and sowed the seeds of upgrade.
No worries. I’ve been after one for a while. Without the tax it was the best price I could find. With tax, it’s only $5 more than the best China or US price I could find, and I’d still have to pay (an unknown amount) of duty/tax, so it’s good. The others didn’t come with extra heating elements either. That is a job saver when something fails.
There are cheaper models too, but none that caught my eye like this one. I like the UI, the extra parts, and the little power supply/meter built in is nice too.