In SX Microcontrollers, SX/B Compiler and SX-Key Tool, kgracey wrote:

John,

Yes, at least this is the case for the SX chips. However, this is a complex issue that in my opinion requires some experimentation in your manufacturing line. The confusion stems from the manufacturers. First, some suppliers will transition to lead-free (RoHS, I use the terms interchangeably) and use the same part number. All of the sudden you will receive lead-free parts. Perhaps there's a new laser-etching on the chip; perhaps there is not. Other suppliers will tell you to order a different SKU for RoHS. We've observed a lot of inconsistency in the way this is handled. For example, in the case of a BASIC Stamp, we're switching them to RoHS-compliant but keeping the stock code BS2-IC. The reason is that if the BASIC Stamp is used as a finish good it is likely thrown in a socket rather than mounted to a PCB in a lead-free line. But in the case of the SX, we have new part numbers for RoHS parts.

This is the first point you need to pay attention to when ordering parts. 

The second detail which requires more careful attention is what the manufacturer says about their RoHS-compliant parts. Some manufacturers have told us that their RoHS parts can be reflowed in a standard leaded assembly line with 235C temperature. Others, such as the packaging company we use for the SX (Greatek), tells us that you can not reflow their RoHS parts in a leaded process at 235C because the parts will fall off of the PCB. Instead, they suggest a lead-free solder and 255C reflow temperature.

That's the second point which requires special consideration.

The third thing I'd tell you is that you shouldn't be paying inflated prices for the RoHS version of a part you formerly purchased in a leaded package. Initially, many suppliers indicated that RoHS would have an additional fee of xx cents. Now, I'm seeing that prices are remaining the same (or very close) to the leaded counterparts. 

The result of all of this is that you may have (as we do) double the inventory to build any given product while you make this transition. If you look at our inventory, not only is it increasing at a great rate which causes accountants to shake their finger, you'll see that we have leaded and RoHS side-by-side. This is what it takes. The new SX chips are a good example - we have twice the inventory we'd normally have since customers still require leaded parts.  

The final consideration I'd suggest you investigate is the reflow oven equipment. Our current reflow oven barely reaches the 255C temperature required for the RoHS parts. On my recent trip to Asia, many of the manufacturers have bought new ovens (from Heller, a German company) just for RoHS assembly lines. I think the only winner in this conversion so far is Heller, but it's supposed to be good for the environment over the long term.

You should also note that although you may not sell to Europe, RoHS (or at least the lead-free part) will become necessary if you sell in the U.S. California has passed a law very similar to RoHS regulations which will cause all U.S. destined product to comply with California laws since our lovely state is a probable shipping destination for almost anything. You can see how California influences product contents right now by walking into a RadioShack. Their leaded solder (if they still have it) says something to the effect "California has determined that lead is associated with health effects. . . so be careful". 

I believe you will also see lead times from your favorite manufacturing suppliers increase while this issue is taken more seriously. I know that for Parallax it's a difficult, albeit procedural transition that we're doing to meet the RoHS rules.

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=105762#m105802

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2006 (http://www.dotNetBB.com)