[Gta04-owner] [ANN] GTA04 Keyboard prototype

Dr. H. Nikolaus Schaller hns at goldelico.com
Sat May 12 18:10:09 CEST 2012


Hi,

Am 11.05.2012 um 21:02 schrieb Lionel Broche:

> A couple of quick questions about the keyboard prototype: 
> - is this a flexible PCB? Or could it be printed on a flexible substrate so that surface can be bent?

The prototype [1] is a 1mm FR4 PCB because pressing the buttons needs a quite stiff counterpart.

Bending should be possible, but keep in mind that the buttons we use have 4 solder joints at the corners.
I don't know how easily they break when bending the PCB. But if you glue the bent PCB on a rounded stiff
substrate it could work well.

You could try a company like Leiton (they have an online shop for such flex PCBs):

http://www.leiton.de/flex-pcb.html

> - what are the dimensions of the PCB? how thick should the whole keyboard be with the buttons included?

The dimensions are following the current battery cover. I.e. it is 50x109 mm. The radius of the "ears" is 25mm.
I.e. you can think of a 50x59 mm rectangle with two 25mm radius half-circles.
But this is just the prototype and making a different keyboard PCB should not be a major challenge...

The thickness is 1mm for the PCB and the buttons are Panasonic EVQPQ series (because they are
easily available @ DigiKey):

http://industrial.panasonic.com/www-data/pdf/ATK0000/ATK0000CE1.pdf

Thickness is 0.55 mm. I.e. the total thickness is 1.55mm + any mechanics from housing.

Hope this answers some questions...

Nikolaus

[1]: http://www.handheld-linux.com/wiki.php?page=GTA04%3AKeyboard


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