On Mon, November 26, 2012 7:34 am, Mark Hanchey wrote:
> Reading through the microchip site I saw the new line of touch and
> gesture products they have coming soon.
> http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=3Den559858
> Look to be very interesting, but why only DFN ? I guess they are going
> after the smart phone market but DFN is so hobby unfriendly.
> Surface mount products are okay but I despise DFN and QFN.
> Mark

Why DFN? It's the package that the designers want... well, those that are
designing for large enough opportunities that justify the production at a
$0.85 US single unit cost ($0.60 for 5K+).

I think it is also an advantage that these really tiny packages have very,
very small parasitic capacitance, which makes it easier to make a reliable
capacitive touch sensors.  With cap touch, you're measuring extremely tiny
changes in capacitance- pico Farads for sure.

I was quick to dismiss DFN/QFN packages myself, but this past weekend I
did some hot-air soldering (with solder paste and a hot-air station from
Fry's), and I was quite surprised at how easy it really was. Yep, it
pretty much makes a PCB necessary, but not as big a thing to fear as I
expected.

Matt Bennett
Just outside of Austin, TX
30.51,-97.91

The views I express are my own, not that of my employer, a large
multinational corporation that you are familiar with.
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