T&L Publications

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Engineer1138:
Does it HAVE to be acrylic? How about a higher temperature-capable transparent material, e.g., glass?<p>Wonder if you can get clear Teflon?<hr></blockquote><p>I was thinking polycarbonate- although it, too may be scorched. As for teflon-- not made clear or in sheet without casting it... thus, one-off expense.<p>The surface-mount LED's may be part of your answer... how about scribing the circuit into the plastic, mount the LED's (using CA adhesive) and wave-soldering the board- getting solder into the scribed circuit? (can solder handle the current?)<p>Or, find out how the auto industry attaches that heating element on the rear window. (There are 'crude' fix-it kits for those).

How's this idea? Take a foot of 20-24 ga. stranded wire, strip it, and use the fine strands to solder directly to the SMD LED's, making a spider's web or net. Now you can either hang it in the box, looking like a real spider's web,or super glue the net to the acrylic. For crossed lines & touch points, put a drop of super glue on one strand, let it skin, & touch the other, so it becomes a fixed point.

It does not have to be acrylic. It has to be clear plastic material. I will have to do some research to find out which one can handle higher temperatures.
I would like to avoid using 30gauge wire net. It will be almost impossible to glue the net onto the plastic so that all the lines are perfectly straight and neat. Some wires might hang down.<p>"The surface-mount LED's may be part of your answer... how about scribing the circuit into the plastic, mount the LED's (using CA adhesive) and wave-soldering the board- getting solder into the scribed circuit? (can solder handle the current?)<p>Or, find out how the auto industry attaches that heating element on the rear window. (There are 'crude' fix-it kits for those).
"
those sound like two very nice ideas.
Can you explain a bit more about the 1st one? I am sure solder can handle the currents w/out much loss. But how would I laydown nice even lines of solder (w/out melting the plastic)

Have you considered an alternate method of assembly? For example, the LEDs could be placed in holes in a piece of wood and the wires soldered on.The wires could be kept under tension by string them between nails, and making solder joints where they cross the LED leads. After the array is assembled, a sheet of plastic could be glued to the LEDs before removing them from the jig. The wires can then be glued down with coil dope or clear nail polish.<p>Another method would be to align the LEDs with a jig, wire them up with fine wire, and then embed the connections in casting resin, rather than trying to glue them to a flat sheet.<p>It also depends on the size and style of the LED packages.<p>[ April 16, 2005: Message edited by: stephen ]</p>

The self-adhesive copper foil is used by stained glass hobbiests to wrap the edge of the glass which is then soldered to the next pane.<p>Radio shack used to sell lead foil tape (and connectors) that would stick to the inside of glass windows for burglar alarms.<p>A see through robot with clear circuit board would be cool looking too.<p>I have a glass credit card sized calculator that has a liquid crystal display and circuit traces that are practically invisible. Thin and multilayer, it was cheap, probably made in late 1980's, but fragile. It was apparently not a popular item, but certainly unique, and am glad I kept one.