Repairing Solar Cells

[VERA]

Editors Note: This is pretty vague, you really should post some informational detail. Otherwise we waste all our effort finding out what you are actually trying to do. Details will really help get the info you need in a efficient and timely manner

[DanG]

Can you get voltage readings from exposed substrate?  Conductive epoxy may bridge over where the white tab is missing or maybe use the back plane conductive coating to try picking up voltage from that directly. Ra-didio shack has a 'pen' applicator for it or automotive supply house for a rear windscreen defroster kit are common sources of conductive glues...  I've gotten solder to adhere to very small spots of the white pad but the heave & shrink of heating cycles most likely will cause conductors to break free.

I know the white tabs can be poisoned from overheated rosin-core solder film that builds up on a too-hot solder gun, a wipe with rubbing alcohol will allow it to accept solder again...

[VERA]

Sorry DanG.,First time posting.These are the wax coated 3x6 cells sold on E-BAY.The two tabbing strips on the front of cells are mostly torn loose and the white strips you solder to came off with them.You can get voltage readings,just nothing much left to solder to.I will try radio shack.I was hoping someone knew what this material was? It needs to be some kind of conductive paint?that you can solder the tabbing to.Thanks for the tips. I was looking for the product used by cell manufacturers.Might have to glue them on with epoxy?Thanks.

[DanG]

I did a few front tab repairs & found I needed a tool to hold tabbing flat across cell width, ended up using a small square of window glass as straight edged, heat proof but not a good heat sink. A rapid float of the iron tip across the entire width of the cell, one operation, but I also had some rosin-core solder paste that I smeared on tabbing strip back before soldering. Also to get front ribbon as smooth as possible without flattening it, the slight hollow to it holds solder that strengthens the cell and perhaps adds to the conductor size to reduce resistance of the bronze metal they use, esp. with silver bearing solder...

Those tricks really helped, but I haven't seen it rosin 60/40 solder paste available locally lately. Good luck with the conductive epoxy, look forward to hearing your results!

And who knows what the fab plants use, all trade secrets...

[cyplesma]

for tube of flux with 60/40 rosin core solder try plumbing section of ace hardware (in states anyway)

radidio shack should have 60/40 rosin core solder on the shelf, unless you nearby a radidio shack that is in a small town and they don't carry everything (I have one of those 5 driving miles, there's a better stock one 14 miles away)

[howlet]

Hello, Phillip Hurley authored a book on building solar panels. He also has a remedy for replacing solar cell "fingers" by using a conductive epoxy pen. He  recomends drawing the line with the pen, allow it to dry for 24 hours, apply flux, then add solder to some tab ribbon, then solder tabbing to the cell. Ive never tried it so I dont know how well it will work. Hope this helps! JB

[wayne]

I use this pen  http://www.mgchemicals.com/products/8420p.html  but close to $20.00 bucks a pen. Make sure you let it dry 24 hrs. This is and still a problem with waxed cells the tabs come off easy. You look at front of cell and see how much white is showing, this is good, but no white line this is bad news! Need a pen.

Wayne

[wayne]

http://www.radioshack.com/sm-see-all-needs-and-wants--pi-2104395.html

Cheaper one!

wayne

[renewablehome]

This is what is screen printed onto the face of cells.May want to try DuPont solamet but if you have a screen printer and the cells are worth the effort,try Al paste and a heat gun.Its what production solar panel skeleton material is.

http://yaguang.en.alibaba.com/product/50231264/51267417/Indium_Series/Crystalline_Silicon_Solar_Cell_Aluminum_Paste.html

[renewablehome]

correction: solar CELL skeleton material.