Soldering Recommendations

With Hot plate

1) For front side use a hot plate (with temperature control) at 250 degrees. When cell is heated to 250º attach 60 Sn/40 Pb tinned copper ribbon with flux.

2) For back side use soldering iron. The iron should be a very powerful one (40W) and the soldering should be done very quickly at the nearly maximal temperature of 390º.

All Manual

1) Apply solder where the solder joint will be on the front contact busbar or back contact strip, or pre-tin the spot using solder wire. Do not exceed 740ºF. (393ºC)

2) Place tabbing strip over the solder joint and move the soldering tip over the spot to melt ribbon. Do not exceed 740ºF. (393ºC).

3) Allow solder to flow - do not dwell on the joint any more than necessary. Excessive temperature and time may result in low pull strength solder joints

Note: A periodic cause of low pull strength contacts after tabbing is the "leaching" of silver away from the printed contacts into the molten solder. This can be minimized by: a) using a solder which contains 2% silver, and b) keeping the tip temperature and dwell time to the minimum necessary for the solder to flow. Use of soldering materials containing silver is not necessary if the proper soldering technique is used

Recommended Equipment, Materials and Tools

· Temperature Controlled Soldering Station: ELVO Type E200-D with Tip E251, or Weller models EC2001 or EC 1001 with EC1201 soldering iron and Weller Tip ETD.

· Solder: ESP 6- SN62-RMA-A paste or Ersin Multicore Sn62 Tin/Lead/Silver wire, 0.028" diameter. Solder composition in both cases is 2% Ag, 62% Sn, 36% Pb.

· Tabbing Strip: Solder-coated (64% Sn, 36% Pb) copper ribbon