Walls your nozzle cannot lay down
Between two neighbouring pads there is sometimes a tenth of a millimetre left. Your slicer drops it silently, and the two pads become one puddle.
fine-pitch rowsA stencil is not just an extrusion.
Extruding a paste layer 0.4 mm thick takes ten lines of code. What comes off the printer is in pieces, with walls the nozzle never laid down and openings closed up. Here is what sits in between.
Direct extrusion
Not printableThe geometry in the file is correct. What comes off the printer is not.
Stenchill
PrintableSame board, same nozzle. The stencil comes out in one piece and lays down the right amount of paste.
What I run into, board after board
Every one of these breaks a naively generated stencil. None of them shows up on screen before the print. I handle them all, without asking you anything.
Grids that end up as one puddle
A fine-pitch BGA has no printable wall between its balls. Shipping its openings as they are means shipping a short circuit.
2D gridsPieces that fall off during the print
A ring of paste leaves a disc in the middle attached to nothing. The stencil comes out in two pieces and the second one stays on the plate.
detached islandsPads that are not pads
Some tools do not place an opening, they draw it stroke by stroke. Miss that and the whole face comes out empty.
stroked exportsThe same pad described twice
A file can place the same opening twice, in two different forms. That alone defeats everything that reasons about spacing.
duplicatesThree exports in the same archive
Nothing says which one is current, and mixing two of them produces a stencil that matches no board at all.
mixed archivesNo filename says what it holds
There is no universal convention. Some exports name nothing at all. Someone has to decide which layer is the paste, and be right.
layer detectionA stencil that does not register is useless
Lining it up by eye means laying the paste next to the pads. Alignment has to come with the part, fitted to the real thickness of your board.
registrationNone of this was guessed
Every decision in the engine was settled against real boards, not textbook cases. A rule that works on a test case and breaks on a real board does not get in.
70
real board files replayed on every change to the engine
8
families of traps handled before you ever see the result
0
settings to know for it to work. You drop your file.
And if you just want your stencil
You have no use for this page. Drop your export, pick your thickness, take your file. Everything above happens during the few seconds of the progress bar.