Advise on Infrared Reflow Oven T-962A

[Codeman]

Hi,
I need to buy an infrared reflow oven to cook some smd boards.
I'm thinking about the T-962A, widely avaiable on ebay.
I have heard that the early units manufactured back in 2006 are bad, but the new ones are ok.

Can anyone confirm  or as experience with this ovens?

Thanks

C.
 

[FriskyFerretReloaded2]

It a typical piece of Made-in-China trash. You would be better off building one out of a toaster oven, even if someone gave you a new T-962A. There are numerous reviews of the oven on the internet. It only takes a few minutes to conclude it's not worth purchasing.

[Codeman]

Thanks for your awnser.

I did read those bad reviews, but all are old (2009 and such). I see at least one review dated 2011 with good results. I believe that this new versions of the oven are better.

That's why I asked that someone as experience. I don't know what to believe 

Regards

[FriskyFerretReloaded2]

The kitchen counter-top ovens that have a strong forced-air fan inside the oven chamber are the best to use as a reflow oven. The UltraVection oven, manufactured many years ago, is one such oven (look on YouTube.) I converted one and used it successfully without a controller. It was not easy to use because I had to experiment to get the pre-heat timing just right, but it did OK for a few dozen boards and the price was right at $10, used.



To give yourself the best chance at success, you need to use a good, robust solder paste. I would recommend no other than Kester Easy Profile 256 (EP-256) for a no-clean lead-bearing paste, or Kester NXG1 no-clean lead-free solder paste. They are the best-of-class for printing and reflow. They're damn good.

Also, don't think you can buy a small syringe of solder paste off eBay and have it usable for stenciling. Solder paste needs to be refrigerated and once it's repackaged out of it's original factory jar or cartridge, it looses it's stenciling properties fairly quickly, maybe 2 - 3 weeks. Buy a 1000 g. jar, not the cartridge. You need to stir the whole jar for a few minutes just before you use it then "condition" the paste with your metal squeegee.



A top-quality desktop "batch" reflow oven will set you back $5000 US and even those kind of suck on temperature control. I've used them and was not impressed, to say the least.

[Mentor]

These guys are working with a Qinsi QS-5100 and it seems to work well:

http://dangerousprototypes.com/2013/02/14/workshop-video-55-infrared-reflow-oven-qinsi-qs-5100/

Apparently this is very similar to the T962A but without the problems.

[solutions]

These guys are working with a Qinsi QS-5100 and it seems to work well:

Not if you read the comments:

"I’d be careful about assuming it will be satisfactory for small batch manufacturing – it works for one-offs in the center of the drawer. There’s no convection (little fan) as far as I can tell, so it is probably riddled with hotspots around the edges."

[mclinic]

hello

check this hope to be usefull  http://hobbybotics.com/projects/hobbybotics-reflow-controller-v8-03/

[solutions]

The well kept secret is that particular oven (I have it), and a couple of others I have tried out, will not ramp up as fast as the fancy schmancy controllers command. There just is not enough heat produced by the elements.

The ramp rate you see is in the readout the oven's ramp rate - you really don't want it any slower.

Having discovered that, I just do it with a temperature readout. Heat it to 240C, then heat off and crack the door open. Perfect joints every time.

So, for a stock toaster oven, look at what it does. Chances are you don't need a controller at all. I was all set up with a PID controller and am not using it.

[jellybean442]

I've used toaster ovens in the past for reflow, and I've found it useful to profile multiple areas of the PCB with thermocouples. Some portions of the oven (such as the outer edges within a shiny oven interior) will heat more quickly than other portions. You can moderate the uneven heating by shielding these areas from some of the direct or reflected infrared heat by creating a metal shield (heavy foil works fine), then place the shield above and/or below the board to create more even heat distribution.

If you have access to a thermal imager, the shield shape is easier to determine. Just be sure to open the oven door quickly and take a photo as soon as possible.