SMD Reflow Oven T-962

[LinkMTech]

I tried this oven bought off eBay for a couple hundred and it didn't perform as advertised.
They state "complete heating" but it made an oval hot spot in the middle of the tray where only components in this area were soldered and the perimeter was left unsoldered. Then trying to raise the temperature to compensate only burned the boards in the center.

I liked the idea of dialing in the reflow profile once and pushing "Start" then 5 or so minutes later, ding!, done. No joy.

Decided to try a $35 Black & Decker 4-Slice Toaster oven (Model TO1313SBD) with it's claimed "Even Toasting" while requesting the return of the fancy re-flow oven. The B&D oven worked great!

Laid enough PCBs to cover the whole tray
Set the TEMP to 180 degrees C
Set function to BAKE
Set Timer pass 10 minutes then down to 5 minutes
Waited until the heating elements turned OFF indicating 180 degrees reached and started a 90 second timer.
After the 90 second pre-heat time, raised the temp to 200 degrees C for 45 to 60 seconds
At this point it was cool to watch the components quiver and flatten against the PCB as the solder melted.

Now I turned OFF the timer and carefully propped the door open a couple inches for 60 seconds
Next fully opened the door to allow the oven to cool another 60 seconds before sliding the tray out and placing on top of the oven like cooling cookies.

It worked the same with silver bearing and regular lead solder paste.

I may have received a funky unit, don't know. But after some back and forth with the eBay dealer, they agreed to accept the return and fully refunded a$ promised.

[Demon]

...Decided to try a $35 Black & Decker 4-Slice Toaster oven (Model TO1313SBD) with it's claimed "Even Toasting" while requesting the return of the fancy re-flow oven. The B&D oven worked great!....

I had bought a nice convection oven a while back for this. Ended up giving it to my mom when her's started making fireworks so I never got into reflow.

Can you list what solder you use or any other materials?

Do you put a blob of solid solder in a corner and let it flow across the board? Are there good videos of this process?

My hands are shaking more as I get older and would love to use smaller PICs. I "might" be able to still use a SOIC (love these, nice compromise), but I wouldn't bet my house on it. I'd love to be able to use even smaller PICs.

Robert

[mackrackit]

Here are some quick and dirty instructions.
http://www.picbasic.co.uk/forum/cont...MD-Prototyping

[LinkMTech]

Can you list what solder you use or any other materials?

Hi Robert,
I just got into using solder stencils and bought the paste from Chipquick. Using part number SMD291AX250T3 for SMT size 0805 mostly but have other larger parts on board.

PCB/Schematic capture programs:
I only have the freebie PCB programs from ExpressPCB and Pad2Pad that do not generate Gerber files or "Cream" plot but Pad2Pad can export what ever layer is selected to dxf; the board outline and pads for example.

Handling dxf files:
I have AutoSketch 9 that is a simple version of AutoCad where I take that dxf file and remove the holes then resize the SMT pads to about 80% for the solder paste and save as a new "cream" dxf file that needs to be converted to a Gerber file.

Converting dxf to Gerber:
I purchased GerbView to convert my new dxf to Gerber so the stencil manufacture can view and make for me. This was the lowest price I could find for this function.

Stencil connection:
I get my solder stencils made from Quick Stencil. It ships out by the next day! I started out with the kit then only had to order the stencil alone for my other projects from then on since the kit parts are the same for all.

Applying the solder paste with the solder stencil and supplied squeegee is really easy but then comes the part placement. One by one using the tweezers, have to be very careful not to bump a part while placing another is what I had to get used to.

Now pop them in the toaster oven, manually control the temperature profile and I get the manufacture solder finish!

[mark_s]

Louie, thanks for the info on the oven.

I have been using a $18 electric skillet from Walmart with good success. Sparkfun has a
few tutorials using the skillet method. Another useful tool for doing a few parts at a time
is the hot air rework tool found on ebay.

Robert, you need one of these and a bank loan

[Demon]

Mark, I want to build my own; have everything except the controller. I came from CNC group on yahoo exactly to learn electronics for this very project.

I have 2 set of 30" stainless rods for the X and Y axis, 15" rods for Z, roller bearings, steppers, Mach 2 software. Even made my own bearing holders out of liquid plastic (Smooth-On, can even make threads in this grade of plastic).

Once here, I took the scenic root; LCDs, USB, etc. But I know I'm better prepared than ever to make one.

Just sooooo many things on TO-DO list and so few hours available in one day. The 30'x40' two storey garage also took a few years off my journey.

Louie, did you make your PCBs? If not, why not get templates at same time? Back to no gerber problem?

I use QCAD so I get everything.

Robert

[LinkMTech]

You're welcome Mark...

Louie, did you make your PCBs? If not, why not get templates at same time? Back to no gerber problem?
Robert

I get my final PCBs made through Pad2Pad because their quantity prices are good and the boards come out great too, but no way to generate the file for the stencil.
The Gerber files are available from Pad2Pad for about $25 but I would still need to generate the cream Gerber file from those so I found my own way for now.

I forgot to mention, Quick Stencil will accept CAD files. Found out after getting the dxf to Gerber converter.