LitePlacer.com forums

Hello you all,

thanks for your great help! We found the mistake, we confound the wiring of the A-Stepper, B1 and B2.

Now, the rotation is in the right direction, and the small condensators are nearly in the right postition (see attached pic).

But the postitioning of the parts is not so accurate as we wish. We fear that the small variations of the postitions could cause problems when placing the ICs.

Does anyone has a hint how to improve the accurateness of placing?

Thanks in advance!
caprisonne

The small rotational error is probably caused by the capacitors sitting a bit loose in their tape pockets... So they are not 100% straight when being picked up.

Neat trick to fix this:
1. Place the piece of part tape in your holder or tape it to the table top (double sided tape), keep the cover tape in place.
2. Run a magnet along the side of the tape; the parts will all move towards the edge of their "pockets" and thus straighten up.
3. Carefully remove the cover tape and happily place well-aligned parts.

As for XY-position, it looks as if all parts were slightly displaced to the right (+X).

I recommend you repeat camera-needle offset and wobble calibration. Follow Juha's instructions in the right order; the most crucial part is camera-to-nozzle offset followed by setting up cam position and nozzle wobble calibration. I repeat this before every job.

Also make sure, your down camera is perpendicular to the table and cannot move in its holder. If you use the andonstar camera, make sure to fix the cable as the optics tend to move inside the metal case.

To get best accuracy for ICs and larger parts, I think bottom vision support is the missing feature - i.e. move part over upwards camera, measure displacement and rotation and compensate these during placement.

There has been quite some discussion about this here recently.