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Subject: Re: [Homebrew_PCBs] CNC mill X-Y tracks?

From: uhmgawa <uhmgawa@...>
Date: 2005-06-24

David McNab wrote:
> But at some time, I would like to replace this crude abomination with
> something similarly simple but better.

Something else to keep in mind is using the XY
setup to assist with pick/place operations for
SMD devices. Dealing with placement of any
significant number of 0603 or smaller components
per board can get tedious quite quickly.

Also even larger components such as high pin
count packages commonly have pin pitches of
0.5mm or less. Accurate alignment by hand
here as well is tedious.

Another area where semi-precise placement would
be handy is dispensing of solder paste. There
are methods which are somewhat forgiving of
the errors encountered in manual placement but
they usually involve a "check and fixup" step
which could be eliminated by accurate dispensing.

I don't foresee here the need for something as
elaborate as a commercial device feeding off
components dispensed via tape & reel, but rather
a tool allowing semi-automated placement of
paste and components onto a board. The solder
paste could be dispensed via screw-driven syringe
substituting for the drill/mill head. Component
placement could be made by a vacuum head able
to articulate at least +/-180∗ normal to the board.
The idea here is the vacuum head could under
operator control pick a component, rotate it to
position and place on the board into the previously
dispensed paste.

Getting this far would be cause for celebration but
a useful addition which quickly comes to mind would
be the addition of a small CMOS camera to the head.
This would dismiss the need to crouch over the
works donning a jeweler's loupe during the above
operations.

--
uhmgawa@... www.gnu.org