Right now I ramp from 25C to 150C in about 1 minute.
If the temp rise too quickly, it will burst and make a mess (the tiny solder balls will be everywhere just as you observed). So slow down the pre-heat phase may help solve the beading issue.
My oven is a convection oven. About 0.9 Cu Ft. 2600W. So the heating is pretty even. but the temperatire of the circulating air can ramp pretty quickly. I can impose a ramp rate instead if just letting the elements heat the oven as fast as possible between steps.
The elements are 4 on top, 4 on bottom. All equally driven.
This is becoming very interesting with respect to the effect of ramp rate and paste melt result.
You got a powerful oven, so try to slow down the pre-heat curve and make sure there is no temperature over-shot into the reflow zone during the pre-heat period.
No temperature over-shot on your powerful oven is also important to prevent creating a mess due to solder paste burst.
well for those of you wanting the new reflow controller,
its coming in abuot 2-3 weeks! (assuming the pcb’s test out ok,… but they should i went over it like 3 times…)
its will be hardware version 3.0
lots of new features…
some last minute options in addition to the ones we posted:
-pcb will be done on high temp Tg=170 deg C
-optional high temp terminal blocks at order time (getting max temp of them from company…)
-normal term blocks rated to 100 deg C
-or order without term blocks…
small 1.5" x 1.5" reflow oven controller!
very excited to have this new version coming out!!
will drop a line when its out.
we will be redoing the software also, adding new features. until the software update, it will have the same great features as before and as always the open source code.
Is there anyone here who’d like to sell me a pre-programmed 16F88 for the SparkFun Reflow Toaster? I’m not a PIC guy, so I’m not set up to do the programming myself. I tried the low-end Olimex dev board route, but something in my software/OS/serial port/cable/programmer lashup isn’t right, and I’m exasperated enough that I’d rather spend some money than try to debug something that I’m not likely to use again.
Of course, it’d be even better if SparkFun included a programmed chip, or sold them separately, hint, hint.
Then again, it appears to use a low-cost convection oven (Severin TO2020 - not infra-red), and the controller doesn’t look as useful as the one from Silicon Horizon.
It saves a bit of effort, at a cost, but I don’t know how good the solder joints would be. IR toaster ovens don’t seem to be available in Europe.
I have a controller all set up, using the Silicon Horizon board, waiting for my Infrawave oven. (I bought one on eBay in March, but it has disappeared in the postal system, with no tracking number - so after that was refunded I am now waiting for its replacement to be delivered, this time with a tracking number).
I bought a small IR toaster oven from Argos here in the UK - £19.99. it worked OK when I tested it with some solder paste on a scrap piece of PCB material. I was intending to make a controller for it, and got a suitable thermocouple, but haven’t got round to it.
hey leon i see your using the DDS chip from analog…
did you know u can do ramps from them? yep. you do it by using 2 DDS chips. one feeds the phase of the other a square wave. then the 2nd one puts out the ramp.
pretty cool chips…
just letting u kow so you can make a “complete” signal generator hahahha.
that way youll have sin,square,ramp,triangle, everything.
in addition to FSK and PSK.
not a bad chip.
im using them in a design right now for a 400mhz to 3.5 ghz transmitter.
I built a sine signal generator with one many years ago, when they first came out, it was useful for testing filters. I used one in a simple DC receiver controlled by my PC, as well.
Both my Yaesu transceivers have a DDS, as part of the PLL synthesiser.
but i do concede to get the 400 mhz to 3.5 ghz im using 4 PLL’d VCO’s !!! yep that does get a little pricey.
all 4 VCO’s have similiar specs and VTUNE voltage ranges… so it makes it easier to “stamp” out separate band designs since everything is tunable with PLL’s / Synths / adjustable BW of source signal etc…
the idea here is completely tunable, and highest accuracy possible.
this design is modular… consisting of 3 PCB’s…
1 PCB will have the spectrum analyzer utilizing an RF log amp to put the level in the bins and display on GLCD.
the other 2 PCB’s each contain 2 VCO’s each to get the full 400 mhz to 3.5 ghz range.
all will be controllabel via the 1st PCB’s MCU…
and modular, you can pick what pcb u want and add the others when u want by just changing firmware.
the design is small, 2.5" x 3.5 ".
hopefully will get a pcb done within the next 2 months of the 1st transmitter PCB.
the spectrum analyzer is the hardes one to do…
an RF mixer with a LO freq, then off to an IF stage which will hold the RF log amp. so sweeping the freq range, then stop to check RF log amp level, then keep on sweeping… thats how this one will work and update accordingly on the GLCD in the appropriate bins.
this is a handheld device.
trying to keep it down to 4 layers… not making it too small.
