I recently started a company that uses BTU Pryamax reflow oven (7 heat zones, 2 cooldown). Any advice on creating profiles for both leaded and lead free products? also what can you tell me about oven profiling with this model? i'm told it has built in software for profiling. has anyone used it?
I haven't used this oven; but, our Heller has built in profiling. Essentially, attach the thermo-couples to a board, and the appropriate point on the oven, and run a board (without parts).
Your paste manufacturer will have published a recommended profile for their paste chemistry. You'll need that information to help with creating the profile. If you call your paste manufacturer, and tell them the model information on your oven, they should be able to give you base-line settings for the different zones, as well as belt speed for their paste. Use these settings as a starting point to build a profile for the boards you're running. We've found that about 60% of our boards run on the base line settings. Boards that need adjustment are either significanly thermally dense boards, or thermally non-dense boards.
Protective sleeve? The sleeving protecting the wires of the thermocouples?
I bought mine direct from Heller. I think it was $90 for a set of 3 (my oven uses 3 thermocouples). They are close to thirty feet long (I'm guessing...they're much longer than the oven), and came complete with the connection to plug into the oven.
I believe they are k-type, but, don't quote me on that.
I'd say check with the manufacturer of the oven, to see if you can buy some thermocouples from them for profiling. That way, you know you're getting a product that works with the equipment you have.
Type K thermocouples are the most commonly used in the electronics industry.
There are various types of thermocouple types that can be used. Examples include [Ray Prasad]: • Type K ¾ nickel-chromium vs. nickel-aluminum (most commonly used); temperature range is -200º to 1250ºC, ±1.5ºC. • Type T ¾ copper vs. copper-nickel (easy to solder); operating temperature range is -200º to 400ºC, ±0.5ºC. • Type J ¾ iron vs. copper-nickel; operating temperature range is -210º to 800ºC, ±1.5ºC. • Type N ¾ nickel-chromium-silicon vs. nickel-silicon-magnesium; operating temperature range is -200º to 1,280ºC, ±1.5ºC.
IIRC the IPC spec for oven profiling says the thermocouple leads should not be more than one meter in length. I think when you can afford it, getting a data logger to go through the oven would be a good idea.
But if you are going to use the very long thermocouples, it is a good idea to get an empty large component reel. Before we got our data logger we would wind the thermacouples up on an empty reel. The thermocouples can be fragile and can kink up especially with the long lengths. Winding it on the reel helped keep them unkinked.
Starting out, get a Vmole from ECD if you are worried about the cost. Fairly inexpensive, and you get a good in oven profiler, decent software that allows you to do some prediction and profiling tracking and lots of oven models preinstalled.