Placing 0402 Components (It Definitely Works)

[Stefan]

Normally I don't go below 0603 conponent size on my boards, but due to a design issue I suddenly needed to add a whole bunch of 1000pF capacitors in an area that was pretty much full, which meant I had to use some 0402s.

The Liteplacer definitely can place them, however, it needs to have the Camera to Nozzle calibration spot on. With larger components you have a much larger fudge factor.

The first problem I had was simply the nozzle not picking up the capacitor. The smallest nozzle is almost too big, so if the calibration is off you can get jammed components, missed pickups, or even tombstoned components on the nozzle.

The second problem was that the component would stick to the nozzle. This was happening initially even when the component was placed correctly. I ended up increasing the vaccum release time to 600ms.

A third problem is that missed pickups need to be stopped with 0402s. Even with the nozzle to camera calibration correct, the nozzle is large enough that it jams itself into solder paste when it tries to place with no part. On larger components the nozzle usually lands in a spot with no paste. Solder paste can and will clog the nozzle, and thin wire can unclog it. A clogged nozzle will result in missed pickups of even larger components.

Stopping a missed pickup is currently a massive pain in the ass. The stop button in software leaves the software in a state where the home button will only home the Z axis, and doesn't do anything with the other axis. I needed to restart the software to continue.

This leads to another software bug. In the release of the software I am using it thinks the vaccum pump is on when it is not. If I don't toggle the Pump On checkbox it will start placing without the pump on, which is a great way to jam the nozzle with solder paste if you are using 0402s, or your nozzle to camera calibration is off.

[santosp]

Indeed the Stop button in "Run Job" page goes the machine to a very messy state. I have inform Juha for this some time now.
After this I also loose the pump operation. The worst thing is that to work normally again, I need to close the software and power off the tiny-g for a while. Some times more than one time....

[JuKu]

I’ll look into this asap.

[pete0]

Hello JuKu,

have a look to your github, issues #53 and #56.

Within https://github.com/petegit/LitePlacer-DEV I have committed a workaround for these problems.

https://github.com/petegit/LitePlacer-D ... ad68bc4f3a
https://github.com/petegit/LitePlacer-D ... 5e639077a4

Regards,
Peter