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N_Cook N_Cook is offline
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Default TIP: Making connection to 0.5mm spaced lands/conductors.

Wanted to extend a small LCD display out of its little commercial box,
by about 1m.
Ribbon and ZIFs between the lcd pcb and main pcb was 0.5mm spacing.
No profesional micro-soldering kit available, so poor-mans bodge/kludge.
Some copper mesh from a craft shop, something to do with decorating
birthday cards/scrapbook or jewellery or the like. Anyway uses 0.12mm
diameter wire , woven into a mesh of 0.33mm spacing.
Cut a length to span width of original ribbon and width enough to bridge
and fan-out the gap to 0.05 inch ribbon or appropriate header, that
eventually can be well anchored to the main pcb. Work under illuminated
magnifyer or x10 USB microscope viewing.
With good thin nose pliers remove filaments widthwise until about 6
filaments wide bit of mesh remains, enough to just hold the weft/warp?
fibres in place, carefully disposing of those waste lengths of long
wires. So protruding wires on each side. On one side fold back the ends
of every other wire 3 times ,then leave extra 1 in place, and repeat
along ,so every 3mm matches up 0.33 to the 0.5mm spacing.
Tin all the ends of the wires. Liquid flux the lands at the ZIF socket.
Temporarily clamp mesh to pcb and align the wires, using a needle. Find
the finest of sewing needles, heat and push into a blank of hotmelt rod
as a handle. Grind back the eye end until a tiny Y shape.
Unclamp the mesh and continue removing the last 6 wires, careful about
retaining all and disposing of these tiny bits of wire.
For each soldering fill the Y with solder paste, and heat the Y area
with soldering iron. Hopefully the bond between wire and land is better
than to stainless steel. The de-deforming force of stripping the last 6
wires, is a good test of mechanical bond. Check continuity and isolation
and slide some thin sleeving over each wire, perhaps lacquer in place.
With wide spaced ribbon or whatever fixed to the pcb, solder the other
end of the wires . Recheck continuity and isolation.