Screen Tablet malarky => Tutorials and useful knowledge => Topic started by: janm on December 01, 2011, 12:20:36 PM

Title: DIY FFC extensions
Post by: janm on December 01, 2011, 12:20:36 PM

Hi Guys,

Here's a quick guide to show how I extended my FFC cables for my build. Reasons for this were time constraints and I could get hold of the parts required quickly...

I used...

Pairs of FFC sockets of the required pin number and pin pitch. (see pic for the type you need)
Soldering Iron with a fine tip, solder, flux pen, flux cleaner pen and desoldering braid.
I used a mini vice to hold the ffc sockets together and hot glue to insulate the pins after soldering.

This is a post showing how I did my extensions. I cannot be held responsible for any damage to equipment or personal injury that
might occur if you decide to do this yourself.

Its pretty simple really...

I took a pair of ffc sockets and aligned the pins with a slight overlap. I held these in a mini vice to make sure they were held firmly and applied some flux to the pins.

I tinned my soldering iron ( coated the tip of the soldering iron with solder) and using the solder from tinning only touched the pins
with the soldring iron tip. The flux allowed the solder to flow onto the ffc socket pins...

If i bridged the pins i used the desoldering braid to remove the excess solder from between the pins and continued.

After I soldered the pins of the ffc sockets together I removed the excess flux with the flux remover pen.

Then checked the connections with a multimeter to make sure there were no bad joins or bridged pins.

Next I applied hot glue over the soldered pins to insulate the pins.

Sorry for the quality of my pics they were taken from my phone camera...


Title: Re: DIY FFC extensions
Post by: Dragon on December 13, 2011, 05:15:13 PM
Awesome, Jan.

I tried doing something similar but since my pins were staggered, one coming out the top of the connector, the next coming out the bottom, I couldn't solder them together like you did.  So I figured I could extend my cable even farther and soldered 30 12-inch wires between the connectors.  Five hours later, after carefully testing, my monitor worked but was filled with static over the whole screen!  I don't know if my whole cable was just too long or more likely the tangle of wires were interfering with eachother.  The screen static would move around as I gently moved the wires.

I later found I could pull the pins out of my connectors and flip them around so they're all on the same side.  Luckily I got two extra connectors so I'll try soldering them back to back like you did next.

Title: Re: DIY FFC extensions
Post by: Dragon on December 13, 2011, 06:27:51 PM
Oh, I also meant to ask if leaving the flux residue on the connectors would have a bad effect?  I don't have a flux remover pen.

Title: Re: DIY FFC extensions
Post by: bernard on December 17, 2011, 10:50:23 PM
Normally you should use a flux remover because I think flux can have some chemical effect in the long run. But it is not that bad, most of the soldering wire nowadays comes with a "core" flux and rarely people use flux remover products.

Title: Re: DIY FFC extensions
Post by: janm on December 21, 2011, 09:59:09 PM

Yes its probably the tangled wires thats causing interference.
I had some interference when I tried to shield the ffcs with aluminium tape.
I had take the aluminium tape off again.

This screen is very suseptable to interference particulary on the lvds ffc.

Its good practice to use flux remover so I just use it when I can.