Author Topic: TSOP Rework (Read 13042 times)

orion242 · « **on:** September 30, 2015, 02:11:36 am »

Anyone use one of these stencils for tsop rework?

http://www.stencilsunlimited.com/flip-up-stencils-p-362.html

Wondering if its worth the cash or not. Looks like it would be nice to get in and lay down paste on a populated board.

marshallh · « **Reply #1 on:** September 30, 2015, 02:41:54 am »

Why even bother? Just drag solder it. Done

orion242 · « **Reply #2 on:** September 30, 2015, 02:59:46 am »

I want more consistent results and less time with solder wick.

John_ITIC · « **Reply #3 on:** September 30, 2015, 03:27:28 am »

For TSOP, just flux and solder under microscope. Clean with isopropyl alcohol. There's no need for anything fancier.

orion242 · « **Reply #4 on:** September 30, 2015, 12:57:45 pm »

Sounds like I'm better off shopping for optics which is one area of my shop that is lacking.

Thanks

neslekkim · « **Reply #5 on:** September 30, 2015, 02:08:21 pm »

Optics, and a steady hand.. TSOP is very easy, it's scary the first one, but then it goes supereasy.

I wonder if it was one of these videos that helped me: https://www.youtube.com/user/MrMarcSiegel/videos
tack two oposite corners, adjust, and off you go.
(buy some practice kit from ebay or something to test.)

Macbeth · « **Reply #6 on:** September 30, 2015, 02:16:24 pm »

Quote from: orion242 on September 30, 2015, 02:11:36 am

Anyone use one of these stencils for tsop rework?

http://www.stencilsunlimited.com/flip-up-stencils-p-362.html

Wondering if its worth the cash or not. Looks like it would be nice to get in and lay down paste on a populated board.

What a crappy website. Most of the photos appear to be poor quality blow ups of tiny thumbnails. I wouldn't trust the quality of their stuff at all.

nctnico · « **Reply #7 on:** September 30, 2015, 03:24:44 pm »

Quote from: neslekkim on September 30, 2015, 02:08:21 pm

Optics, and a steady hand.. TSOP is very easy, it's scary the first one, but then it goes supereasy.

Indeed. Use a very big flat tip (like >3mm wide) and some flux. If there is bridging there is too much solder on the tip. Remove that, add more flux and touch again.

orion242 · « **Reply #8 on:** September 30, 2015, 03:33:29 pm »

Roger.

I'll to have to spin a quick PCB with nothing more than tsop footprints staggered over it to get some practice and find some cheap parts to play with.

The few I worked on so far did end up usable, but it wasn't all that pretty. Bridges, hit it with wick, then it looks too dry...whoops too much heat, pulled the wick a bit and now a pad or two lifted...

Way too much time dicking around with a shitty usb microscope checking the results and constant iron / wick passes to be trying this on PCBs and obsolete ICs I need.

neslekkim · « **Reply #9 on:** September 30, 2015, 03:33:51 pm »

Quote from: nctnico on September 30, 2015, 03:24:44 pm

If there is bridging there is too much solder on the tip.

Or to little flux..

KL27x · « **Reply #10 on:** September 30, 2015, 07:07:00 pm »

I'm also in the drag-solder camp. TSOP is way easier to hand solder for me, and I have found this out time and time again. I say this having just assembled a batch of boards totalling ~ 1000 components in the last two days; after the first couple boards, I set the damn stencil aside. It's partly my ineptitude at pasting a board, for sure. But the gap really isn't that big if you have perfected a drag-soldering setup.

Next time I order a stencil, I will be omitting leaded IC's from the stencil and just stencil pasting the passives and transistors. It's the IC's that ruin a stencil pasting. I can get a good paste on the passives 100% of the time, but I'm still at the point where I will get too much paste on the IC pads nearly half the time I do a stencil. (Also, with flex, some of your IC's will not connect because the board will flex in the oven! Yeah, you could tape everything down, but the return rate on the stencil for leaded IC's is already practically nil). Reworking the ICs due to too much paste requires more work than drag-soldering them in the first place. The one time you have to wipe off a board and restencil it, the one time a chip turns and lines up wrong due to too much paste, the inevitable inspection, flux, solderwick routine even when things go mostly right... this stuff eats up an enormous amount of time.

I am pretty sure stencil pasting is one of the least pleasant jobs around. Forget the pnp machines. Wake me up when someone creates an automated, self-cleaning stencil pasting machine.

Pace calls their drag-soldering tip a "wave soldering tip," for good reason. With a proper drag-solder tip that creates some surface-tension-induced suction, you're essentially doing precision wave resoldering. This is way more reliable and less labor-intensive on IC's than pasting, IME.

I can't get a hollow/spoon tip for my iron. A tinned face only bevel tip is the best I can get for my iron, and it works great for most all my SMD needs. A proper drag-solder tip sucks out bridges with ease, unless you severely overload with too much solder. A trick I just picked up on this last batch to avoid overfilling the iron is to overfill the decoupling cap pads. Then when you go back for the IC, you can lightly load the iron for drag-soldering by touching the decoupling caps.

I may have to check out those stencils for leadless parts, though. Pasting the IC, only, should make it easier to get a good paste without the cost and hassle of buying/machining a reference-flat cutting board custom sized for the board and using extremely stringent technique to get a good paste. Maybe it could be useful for individually pasting the IC's after doing a stencil for the passives. Again, I personally wouldn't bother for TSOP.

Quote

Sounds like I'm better off shopping for optics which is one area of my shop that is lacking.

Sounds like a good plan. When paste reflowing TSOP, you really need to visually inspect it, after. This is part of the reason hand-soldering is easier. You are inspecting it as you install the chip. When you're done soldering, you're done inspecting. I would ditch my reflow oven and paste solder before my microscope.

orion242 · « **Reply #11 on:** October 01, 2015, 01:26:02 am »

I seen the "solder wave" tips and they look pretty slick. Xytronics doesn't seem to have a knock off and I use their 1/8" semi-chisel for pretty much everything.

So not being an optics guy... how suitable is this scope going to be for electronics?

http://www.amscope.com/microscopes/3-5x-45x-boom-stand-trinocular-zoom-stereo-microscope-54-led-light.html

I can toss ~$500 out for something decent. Don't really need trinocular, but it doesn't seem to impact the cost much. Is there any downside to the wide field eye pieces or anything else I'm going to kick myself latter if I pull the trigger on this guy?

KL27x · « **Reply #12 on:** October 01, 2015, 02:15:04 am »

Pretty good, IMO. But I'd consider spending another $100 for the double boom arm stand.

Quote

Is there any downside to the wide field eye pieces

I think "Super WIDE FIELD" is just a selling point rather than a specific type of eyepiece. The WF10X eyepiece is the standard on all Amscopes, AFAIK. And it will give a 2.5" FOV only with the 0.5 Barlow at minimum zoom of 3.5x. You can buy 5x eyepieces, but apparently they reduce the FOV, some, so you will not significantly increase FOV by going lower than 10x. Most people will find the 0.5 Barlow to give a pretty ideal range of zoom and working distance for soldering/inspection.

orion242 · « **Reply #13 on:** October 01, 2015, 02:18:40 am »

Double boom it is.

Thanks for the help!

KL27x · « **Reply #14 on:** October 01, 2015, 02:43:51 am »

Quote

Xytronics doesn't seem to have a knock off and I use their 1/8" semi-chisel for pretty much everything.

I have a Xytronics and a Hakko 888. They both take Hakko T18 series tips. I bet yours is the same. Last I checked, Xytronics only made one kind of soldering iron, and it's a close Hakko clone except the connector is different.
Oops, I mixed up. I meant X-tronic.

orion242 · « **Reply #15 on:** October 02, 2015, 03:01:01 am »

LOL.

Oh well they are cheap enough and look close enough I ordered a few to see if they fit.

I got the double boom scope with 0.5 & 0.3 Barlow lens, upgraded the lighting, added dust cover, and a handful of these tips. I'll post back once I get it all here and try it out. Can't see being disappointed with the scope and the tips were cheap regardless.

Thanks again, no worries.

orion242 · « **Reply #16 on:** October 08, 2015, 01:40:33 am »

Tips fit my iron pretty well. They are a tiny bit shorter than the xytronic tips where the retainer holds the tip to the very back, but the ID seems to be the same. Compared to the this tip, my 1/8" chisel looks like a snow shovel.

Got a tray of these bastard packages and the scope should get here tomorrow.

KL27x · « **Reply #17 on:** October 08, 2015, 04:32:45 am »

Glad they fit ok!

I really hope you decided to try one of the tinned face-only bevel tips.

A knife and/or a chisel tip will do a prettier drag-solder, hitting only the toe of the pins. But if your hand shakes or slips, you can make a bridge. You can see in this vid how using a 3mm bevel tip, you drag solder on the top of the pins, and still there's no bridging. If I make bridges, I don't stop. I just go back, and they suck right out like nothing! My CF2 is great, but after watching this and seeing him call out his CF3, twice, I decided to order the T18-CF3, too. According to the Hakko tip selector, the T15 CF3 is a normal 3mm, 60 degree column/bevel tip, but in the video (not the tip in the vid cover) it sure looks like his T15 CF3 is TFO, like the T18-CF3. He has probably used just the face so long, the rest of the tip oxidized.

orion242 · « **Reply #18 on:** October 09, 2015, 01:43:03 am »

Well I think the tips really made the difference over my snow shovel. Inspecting the whole damn side of the package instantly as you pass over was a big plus. Before even if I thought it was good, its over to the usb scope to check for bridges, then its back to the solder station. That thing can't see one side of the tsop48 without slowly passing over the sides. Now I can see them all at once. Alignment....10k times easier.

I might have to get the camera option for this.

This was first go new tip & working under the scope after a dry run or two (yes pictured under the toy usb scope...).

Thanks again guys.

singapol · « **Reply #19 on:** October 09, 2015, 02:29:27 am »

Quote from: blueskull on October 09, 2015, 02:06:55 am

I use a hot air gun to desolder everything, then for a TSOP, I use a solder iron, solder wire and ample flux.

I would advise to use proper hot air soldering station like Atten858 or similar clones. It has better temperature control than hot air gun plus different sized nozzles since you are buying good test gear
might as well go professional all the way. It's less bulky so easier to handle especially for tiny smd.
Hot air gun will be blowing air too strong.

orion242 · « **Reply #20 on:** October 09, 2015, 02:35:31 am »

I have a board heater to hit the bottom and hot air gun with tsop adapter for the top. Getting them off was easy. Sticking them back down was a complete PITA.

It took too long and the results not pretty with the old tip. Had I started with the right tip, could have got the job done with acceptable results bare vision I suspect. Still the amount of inspecting with a shitty usb scope would have still taken more time than I want dinking around with these.

With the amscope there is no need to inspect afterwards, its right in front of your eyes real time and alignment is simple. Makes short work of them.

nanofrog · « **Reply #21 on:** October 09, 2015, 08:13:32 pm »

Quote from: blueskull on October 09, 2015, 02:59:34 am

I use a Quick 957DW hot air station.

Mind doing a teardown and review thread?

It would be highly useful IMHO, as I've never seen a review of one (wondering if the build quality exceeds other offerings in it's price segment).

wraper · « **Reply #22 on:** October 09, 2015, 08:34:08 pm »

Quote from: nanofrog on October 09, 2015, 08:13:32 pm

Quote from: blueskull on October 09, 2015, 02:59:34 am
I use a Quick 957DW hot air station.
Mind doing a teardown and review thread?

It would be highly useful IMHO, as I've never seen a review of one (wondering if the build quality exceeds other offerings in it's price segment).

You can see the photos here: https://fotki.yandex.ru/users/night-prizrak/album/214525/?p=0

nanofrog · « **Reply #23 on:** October 09, 2015, 11:08:15 pm »

Quote from: wraper on October 09, 2015, 08:34:08 pm

You can see the photos here: https://fotki.yandex.ru/users/night-prizrak/album/214525/?p=0

Thanks for the link.


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Author Topic: TSOP Rework (Read 13042 times)

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