How-To: Add 7135 chips to a Driver Board (Stacking)

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! :slight_smile:

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.

Good find. I was thinking hard about that XTar with hot air station for doing shrink wrap and stuff but in the end I thought a better quality straight forward soldering iron would suit me best. Still cost a little more than I’d have liked, but the way I’m getting into flashlights it’ll be well worth it. In years gone by it would have sat around unused but probably not so much these days :slight_smile:

Hakko is a good brand, and there are tons of brand name and generic parts available online. It’s a good pick for sure. You can just about do anything for flashlights with a 60W solder station. That is the updated design too. I’m undecided on the look, but the function is definitely there.
The key for doing better solder jobs is heat control. Too much heat and you stress the parts. Not enough and you get cold solder joints, broken components, and a lot of frustration.
I’ve managed for almost 20 years without the proper tools for SMD rework; time for a treat. :wink:

So how do you know when enough is enough? How do you know if you’re getting a cold joint?

I generally use the lowest temp that melts the solder smoothly. If the solder doesn’t look shiny when it sets, you do not have enough heat. A cold joint looks dull because the solder crystallized when it set. If this happens, turn the heat up a few degrees, remelt the joint and let it set without having the parts move while setting.
For general electronic soldering, 350C to 400C should do it.
If you use lead-free solder, you will need to be closer to 400C, maybe 425C. My suggestion is to use 60/40 tin/lead rosin core solder (0.6mm, 2,2% flux). It flows like a dream and will keep your tip tinned with only a wet sponge for cleaning. Others swear by 63/37 core solder, but it’s not for me. Leaded solder may not be available everywhere (EU?)
For sensitive situations (i.e. semiconductors) I max out at 400C. If it’s just wire, pins, etc. and I cannot get a good joint I’ll go higher. I will not leave the iron above 400C as it tends to mess up the tip easier, making it difficult to tin.

Relic. Have you ever purchased anything from Newark.com? When I was shopping for a tip, I found them. I ordered a bunch of other things that I wanted anyway. It’s got a Canada page. At checkout, I paid HST, shipping is $8 under 50lbs via UPS.
When I started tracking it, I was worried to see it was coming from the states. I was afraid I was going to get hit with some huge UPS handling fee. Nope. I got it in two days…no extra charges.
One of the things was “tip tinner and cleaner”. I was surprised to see radio shack on the tin when it arrived.
Anyway, good place for cheap fast shipping.

Both Newark and Digikey are great for quick delivery. They both have a special arrangement with UPS. Just try overnighting anything from the US for $8.
Newark has more tools, Digikey has more electronics. For Digikey, if you order in stock items before 5pm (maybe 7pm) it will be at your door tomorrow. Great for repairing an oops. :wink:

Well, I added two chips to a 3.04A driver this evening. One went good, the other…Im not sure. It seems that there’s that one chip that’s easy to get at, and the others are harder. Poor lighting, bad eyes, and just getting weary, no matter how hard I examine the second chip, I still can’t tell if the contacts are connected. Well one of them anyway. I’ll study it again tomorrow. I reflowed an old XPG onto a board and soldered wires with little alligator clips to it. Now I can hook up my drivers to make sure they work before installing them. The driver I was chipping tonight lit it up, so at least I know I didn’t destroy it.
I just thought of something. I forgot to put fresh tinning on the legs of the existing chips before starting out. I wonder if that went against me.

Pre-tinning the base chips definitely helps as you have slightly better access when the new chips is not in the way.
You are testing a 3A+ driver with an XP-G? J)

Yup. I’m not really running it. I just hook it up to the driver, and then touch the battery leads to it, so I know the driver still works after my clumsy modding attempts. It sure was bright though.

Can you tell me about this flux pen I bought? It has a felt tip that presses in, and the flux is like clear water. I don't know if its good or proper for modding. Maybe for applying on MCPCB befor tinning for LED reflow? http://canada.newark.com/kester/83-1000-0951/flux-pen-no-clean-0-33fl-oz-pen/dp/82H2047

Avoid running that bare XP-G star for very long… it will get hot fast.
I haven’t used those pens before. I use a syringe and it’s like corn syrup. Like water seems too runny and would spread out too quick. Give it a shot. Put some on a virgin PCB pad (never soldered) and apply heat and solder. The solder should quickly spread out to cover the pad. This demonstrates best on a longer pad, maybe 3-4mm. If it sits right around where the iron is and doesn’t flow across the pad, the flux isn’t doing a great job.
I usually only use additional flux for reflowing larger IC (8-pin and up). I have not used it on an LED yet, I just reflow by pre-tinning the star, heating through the tinned wire pads and placing the LED when the star is hot enough. I have flux and solder paste, but I’m too lazy to break it out for an emitter.

I tried to reflow an LED last night by heating the PCB from underneath with my iron. I think the metal from the “helping hands” was just stealing all my heat. I finally had to use a frying pan. I need to devise some sort of clamp, or vise grips with leather pads on the jaws to insulate the star. I don’t have a workshop, so everything I do has to be done on th kitchen table.