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Not fully provisioned yet, so not for general use at the moment! Talk to Patrick to get access.
TODO: Insert photos to show the process. In the meantime, check out this Flickr album of the photos showing the process (which will be include inline at some point...)
- Get your PCB made
- Lasercut (etching with cut settings is better for precision) a solderpaste stencil
- Get some spare PCBs the same thickness to use as a border round the one you're going to make
- Take the solder paste out of the fridge. For stencilling the tub of paste seems to work better than that in dispenser syringes, the syringes are best for manually applying paste.
- Set up the reflow oven at
- Get some masking tape
- Get the squeegee
- (optional) Get a flux pen. More useful if you're manually applying paste, rather than with a stencil
- Get your parts
Apply Solder Paste (With a Stencil)
- Tape the spare PCBs down to surround the PCB you're going to solder - see photo. You want a good flat area above that you can swipe down from with the squeegee and space to bring the squeegee down past the PCB you're pasting. Allowing space below the PCB (so "support" on either side) to slide in the next PCB makes it easier to do lots.
- Position the stencil and visually align the pads, then tape the top edge down (to make a tape hinge to allow the stencil to be lifted without disturbing the registration and therefore paste).
- Apply some paste above the stencil across the top
- Wipe the paste down across the stencil, with a low angle (see photo) to flood the holes
- Do a second wipe across with a higher angle to remove the excess
- Carefully lift the stencil and check that there's solder on all the pads
- Remove the PCB
- Repeat for all the PCBs you're going to solder up in this batch
- Once you've done the last board, seal up the tub of solder paste and clean down the squeegee and stencil with paper towel
- Place component(s) the right way round. The vacuum pickup might help for this.
- Power the toaster oven
- Power the controller
- Place the temperature reference board (see photo) (which should be representative of the boards you'll be reflowing) onto the reflow plate
- Load board(s) to be reflowed onto the plate. Place them carefully so none of the components move.
- Close door, making sure the thermocouple wire is routed nicely out of it
- Turn the oven timer to "Stay On" and the temperature to maximum
- Scroll to the bottom of the menu on the controller, to the item labelled "RoHS-dp" (currently)
- Click OK to start the reflow
- If you scroll to the top of the menu to "Dashboard", and click OK then you can watch its progress
- DO NOT LEAVE THE BOARD UNATTENDED. RISK OF FIRE
- Wait for a while until the piezo sounds. About 3 or 4 minutes.
- Open the door to let it cool more quickly
- Wait for it to cool to below 45 degrees before removing from the oven
There is also a Processing sketch to allow you to control the controller over a USB connection.
If you're looking for an idea of what soldered boards should look like after reflow, the NASA Guidelines, Section 7 is a good guide.