Lead or Lead free Parts

[MnR]

Hi,

After looking thru the parts files for the T43/P I find listings for Lead and lead free motherboards and a few other parts. My question is whay are they offering lead soldered parts now as service parts.

Also how are you to identify leadfree parts or leaded parts if you don't open the laptop...

TIA,
MnR (Rudy)

[Bruce Guttman]

You can read the FRU number on your Planar (Motherboard) by removing the external memory cover and the memory module (if installed). The FRU will tell you whether you have lead-free or lead solder.

The shift to lead-free was dictated by the European ROHS (Reduction of Hazardous Substances) regulations. As a consumer you don't really have to worry about whether you have lead-free solder or not (except if you plan on eating it ). Either type of board should work. I'm not sure if the European regulations apply to repair shops as well (PoshGeordie?).

If you are planning to repair a lead-free board, the solder melts at a much higher temperature. Also, fluxes optimized for 70-30 solder are different from fluxes used for lead-free solder. But you can use lead solder to attach a component to a "lead-free" board. This can be important if you plan to try reflowing a ball grid.

[MnR]

Hi Bruce,

Thanks for the reply. Mainly I was wondering why the US boards are using the lead free solder. I have used the lead free solder before for plumbing and other electrical parts and it sucks...

I am a ham operator and have been using StayBrite which is a silver solder. It works great. It will take alot of stress to break a joint. I also use it on My radio control Planes.

I guess if I want to know if any of the parts in the laptops have lead free solder, I will have to take them apart..

MnR (Rudy)

[Bruce Guttman]

I don't know how dense ham gear is nowadays (it's been 30 years since I've been inside any of that kind of equipment), but the circuit board of any recent Thinkpad is loaded with tiny surface mount components and they are tough to remove even on a good day. If you want an idea of what the Planar looks like, find a post by poshgeordie and open the fuse diagram that is part of his signature.

Note that on most T4x and R5x boards there are 3 ball grid arrays which MUST be surface (hot air) soldered. A daunting task at times. One of these chips is the Graphics Unit (GPU) and one controls a lot of peripherals (Southbridge). These things seem to lift when the board is flexed and they result in the most common T4x problems.

As to why a US Thinkpad could have lead-free soldered parts, these things are made for world-wide consumption. If the European models have to have lead-free solder, any board made in Europe, or made for Europe must have the solder. If the Thinkpad will never be sold in Europe (or made in Europe) you could use conventional tin-lead solder. At least for now.

Good luck.