Help with solder profiles for the T 962A oven.

[dimbmw]

I bought a T-962A oven and upgraded it with the firmware by the Unified Engineering.

Now I am wondering - what kind of solder paste should I buy to use the standard profiles.

Or, if I buy, say, this low temp solder past paste - what profile should I create ? 
https://www.amazon.com/gp/product/B017RSGPI8/

Maybe there are some pre-prepared profiles for some standard solder pastes that I could use?

Thanks!

[l0wside]

Any decent solder paste will have a solder profile in its datasheet. The UE firmware also has some pre-programmed profiles. Depending on what you intend to do, it might be easiest to purchase some leaded paste off eBay or Aliexpress and play around. Be prepared to waste a few boards.

Even with the improved firmware and the HW modifications, the actual temperatures of the T962A have the inherent problem of any IR heater: they depend more on surface absorption and distance to the IR source than anything else.
I once tried soldering two-sided PCBs and simply placed them on the large caps, which had been soldered in the first run. The PCB was now about 10mm closer to the heaters.
Result: the burned PCBs still sit on my desk to remind me of this desaster. The room became usable again after about three days with the window constantly open. The smell of burned FR4 is incredible.

[dimbmw]

Any decent solder paste will have a solder profile in its datasheet. The UE firmware also has some pre-programmed profiles. Depending on what you intend to do, it might be easiest to purchase some leaded paste off eBay or Aliexpress and play around. Be prepared to waste a few boards.

Even with the improved firmware and the HW modifications, the actual temperatures of the T962A have the inherent problem of any IR heater: they depend more on surface absorption and distance to the IR source than anything else.
I once tried soldering two-sided PCBs and simply placed them on the large caps, which had been soldered in the first run. The PCB was now about 10mm closer to the heaters.
Result: the burned PCBs still sit on my desk to remind me of this desaster. The room became usable again after about three days with the window constantly open. The smell of burned FR4 is incredible.

Thank you!

Why is leaded paste better?

As for the temp, is there a way to more or less test the actual temps and tune the thing? I think i can attach a thermocouple to the board to check if the board temp follows the set profile and adjust accordingly?

[richardlawson1489]

Don't know much about it but from the reviews from the customer, The solder paste used is low temperature lead free, melts at 137C. This matches the wave 5 temperature profile, up to 160C temperature.

[l0wside]

Leaded solder paste has a lower melting point (about 20...30C lower), therefore a leaded profile will reduce the risk of burning the PCB. Usually, it is also a bit cheaper.

[Yellofriend]

I bought a T-962A oven and upgraded it with the firmware by the Unified Engineering.

Did the same! Including the DS18B20 and the fan control. This former piece of *hit runs very quiet now. The beep now is just a Second and the fan runs when the fan needs to run.

Anybody that has a T-962/T-962A - do that mod! It helps a lot!

So far just did a few tests without parts, just PCB + paste, and I wonder, anybody has a good profile for leadfree solder? I use the standard #2 profile that's in the Unified Engineering HEX. It works, but the PCBs get a tiny bit darker (very minor, still...). Just asking before I start my own experimenting.

[DTJ]

Following along as I'm probably buying one of these next week.....

[coppice]

Following along as I'm probably buying one of these next week.....

Various physical and software mods make sense when you already own a T-962A, and are having trouble with it. If you don't own one, then the QS-5100 makes more sense. Its like a T-962A done more or less right. No machine is perfect, but the QS-5100 is usable out of the box.

[SMdude]

I am using the GC10 paste and it is not too bad, I still am a huge fan of leaded solder though!!
For my profiles, I experimented with some scrap pcb's to find at what temp and time the solder would melt (electro caps and inductors) and built my profile on that.
I also have made a profile for boards without the electro caps and inductors that isn't quite so hot.

Always make sure you mount the larger parts under the heater elements and have your boards elevated off the bed.

I also lowered the temperature probes a bit closer to the board, but don't go too low or those taller parts get in the way.. 

[DTJ]

Following along as I'm probably buying one of these next week.....

Various physical and software mods make sense when you already own a T-962A, and are having trouble with it. If you don't own one, then the QS-5100 makes more sense. Its like a T-962A done more or less right. No machine is perfect, but the QS-5100 is usable out of the box.

Thanks - I had not heard of that unit.

I will have a read up about it. It's a bit above my budget - roughly twice the cost of the T962.

Do you know if it outperforms a modified T-962?

I'm currently preheating boards on an electric frypan and then reflowing them with a hot air hand piece. It's labor-some but it works. I'm afraid I might be overheating parts at times.



https://www.ebay.com.au/itm/New-QS-5100-Desktop-Automatic-BGA-SMT-QS5100-lead-free-Reflow-Oven-/263257279309?hash=item3d4b5b4b4d:g:pJEAAOSwyQNZ3YjN

[coppice]

I will have a read up about it. It's a bit above my budget - roughly twice the cost of the T962.

The QS-5100 should be a similar price to the T-962A. Try looking for other sources if you have found such a high price.

[DTJ]

I will have a read up about it. It's a bit above my budget - roughly twice the cost of the T962.

The QS-5100 should be a similar price to the T-962A. Try looking for other sources if you have found such a high price.

Thanks I'll check out aliexpress

[asmi]

I've posted some photos of one of my boards I've reflowed in my T-962 (just the baseline, not "A" model) here: https://www.eevblog.com/forum/eda/avoid-pcbway-they-are-scammers/msg1277998/#msg1277998
I used leaded solder paste for both sides, and ran the reflow twice - first for the bottom side, then put a board on a standoffs made from some screws and nuts to provide clearance, and ran the reflow of the top side. Even big 1210 caps on the bottom stayed in place and didn't fall. I also did some reflow using LF paste (the board was less complex though, but still had some 7x7 mm QFNs).
If I will remember, I will post a photos of the reflow profiles that I use. Both leaded and LF pastes are of MgChemicals brand (because I prefer buying local if there is an opportunity, and this way I know where to go complain should that become necessary). It was a bit of a trial-and-error process, for which I've bought a bunch of cheapest QFN parts I could find (can't remember now what exactly it was), threw in some assorted passives that I didn't mind losing if something will go wrong, and did several test reflows. Recently as I started using BGAs, I've used several BGA SPI Flash ICs to further tune the process. The advantage of using these exact ICs is that they are in 1.0 mm pitch BGA package, and the pinout is such that you can route it out on 2-layer board. And they are not that expensive unless you plan to ruin hundreds of those - the test board is also designed as a breakout so I can potentially reuse these boards in some projects.
So far I have burnt exactly one part - Molex 2x7x2mm connector - and that was because I didn't bother reading it's datasheet before stuffing it into the oven. And even that one I was able to still use (see photo above).