DIY stencils for reflow SMT
[mattvenn] tested this and it works really well! Here's some photos of the process.
- Export PDF stencil for solder paste from Eagle
- Convert to SVG with inkscape
- Cut a sticky stencil with the Graphtec Craft Robo CC220-20 Cutter
- Apply solder paste with a credit card
- Reflow with the toaster oven
Make the stencil with Eagle
Good tutorial here
Simpler for me in Linux:
- Open board
- Turn off all layers apart from tcream
- Change tcream layer to solid or empty fill
- Print as a pdf file
Make the stencil with KiCad
- Open board
- file → export svg
- only tick 'f paste' & export
Inkscape
- Make a new a4 document
- import PDF into doc
- give a very thin line style (0.1px)
- exported from KiCad - some pads are a thin line with a large stroke, so have to do 'stroke to path'
- arrange on the page - craft cutter sees the page edge fed in as the bottom.
- save as 'inkscape svg'
RoboCut
I installed robocut on the 3d printer computer. It is a very simple linux driver for the Graphtec Craft Robo CC220-20 Cutter.
- open svg
- choose cut from menu
- 'vinyl sticker' preset worked for me
- I used 0.05mm vinyl sticker with the blue 0.1 plunger tip
- I also checked this http://www.ebay.co.uk/itm/191422915226 which is 0.07mm and worked fine too
- check dimensions! I had stretch on Y axis to start with that went away with a different material
Apply solder paste
- weed the holes (remove any of the little bits that haven't come out when you peeled the sticker)
- cut sticker to size (bigger than the PCB helps to remove it)
- apply to board and check alignment
- apply solderpaste with a credit card, more solderpaste works better than not enough
- peel off sticker and save for another board (probably only last for one day)
Assemble components
- smallest, flattest ones first, using tweezers
Reflow
- according to Solder Reflow Oven page