ccd_manual_e
Page 25 /36
Drilling bare boards
When making double sided PCBs with chemical
through hole plating, the first step is to drill the
holes. Any photo processing of tracks and pads
will follow later.
Use a raw cut piece of copper clad laminate and
put it, together with a base sheet of the same
size, on the machine table. Align to the X- or Y-
axis and fix like described under "clamp fixing".
Alternative: Use a big base sheet and fix it by
use of the plastic disks. Put the board to be
drilled on top and push it to the machine's zero
position. Using adhesive tape, fix the board to
the base sheet. Advantage: The fixture position
is independent from the board size. The adhes-
ive tape can be drilled through without damage
to the drill.
Pre-sensitized base material
In the same way as above, pre-sensitized base material still covered with its protection foil may be
drilled
prior to exposure
. As to our experience, this gives best results: There is only one position-
ing operation necessary at exposure time. The drilled image will perfectly fit the etched board
structures. If possible produce your artwork with
transparent drill holes
in the pads. This will
make the referencing process very simply.
Etched PCBs
The already etched board should be drilled. The position of the holes must be exactly the same as
the position of the solder pads.
Look at the layout as the first drill hole with its own tool designation 2 or 6 reference / registration
holes (for example with IsoCam). Place a new drilling pad on the machine table, attach the raw
board with tape, and drill the holes in the circuit board and support. Now expose, develop and etch
your board as usual. The reference holes also help to position the film. After etching, pin the board
by means of reference rivets on the drilling pad and drilling the board.
Routing
Also for routing a base sheet is strongly recommended! Fix the plate by span or clamp fixing. Pay
attention that it lies straight and even.
If, for example, there is a circle to be routed in FR4 material, the inner part of it will most certainly
remain where it was on the base sheet. This will of course work only if you use a sharp router and
set an appropriate speed. In IsoCam you can place gaps in the cut out. These “bridges” prevent
the cut outs to be propelled away.
Engraving
The engraving front panels requires a good flatness of the board. Otherwise, the font thickness
varies with the depth of penetration of the V-cut-router. Here is a safe clamp fixation indispens-
able. For engraving you can work with the depth limiter. However, in this case the cooling is less
efficient, because the milling tool is almost completely enclosed. Another trick is to bend the en-
graving plate a bit, so the the sides of the plate point upward. Now, when you span down both
sides the engraving plate will lie flat on the base.
Bungard Elektronik GmbH & Co. KG, Rilkestraße 1, 51570 Windeck – Germany
Tel.: +49 (0) 2292/9 28 28 - 0, Fax: +49 (0) 2292/9 28 28 - 29, E-mail: [email protected]