What is the difference between ROHS and non ROHS boards?

What is the difference between ROHS and non ROHS boards. In my board I have changed all my DIP packages to smt packages for ROHS compliance. Now the functionality of the board differs slightly from non ROHS board.

can someone tell me the reason for it.

Thanks in advance

Likely...its impossible to differ.
ROHS (Reduction of Hazardous Substance) are needed to keep our environment clean. ROHS product means no Pb, no Halogen, using green molding, green plating, and many more green stuff. The chip are still silicone, but the package are different from usual.
Generally, ROHS leads are more softer than non ROHS. That's all.

Your question is rather open ended. When you ask about a board are you asking about the raw unpopulated PCB or a fully populated PCB?

You also stated that you changed all PTH part to SMT to be ROHS compliant. Changing to a SMT package does not guarantee that you have RoHS compliant parts. What determines RoHS compliance is if the specific part number you are using is offered as a RoHS compliant part from the supplier.

On the subject of raw PCBs, an RoHS compliant card is going to have a compliant HASL coating.

The whole subject of RoHS compliance has confused many people especially when you hear terms like RoHS and Lead Free. To be clear if you have a device or product that is labled as Lead Free that device and or product is also RoHS compliant. HOWEVER you can have a device and or product that is RoHS compliant but it is not (let me repleat that IS NOT) Lead Free.

The term lead free is actually not the correct terminology as it leads people to believe that if there is no lead in something then it is RoHS compliant. In fact you can have a product that has no lead in it and it can still not be lead free.

Lead Free actually refers to an item not having any of the banned substances present in it.

Also many component suppliers have adopted the RoHS ratings that were initially reserved for the equipment suppliers (i.e. OEMs). Those ratings, RoHS 5/6, and RoHS 6/6 where to allow a consumer to know if that piece of equipment was 100% free of the banned substances or if there was some amount of one or more that fell under the percentage by weight allowances.

So do you have a lead free board (RoHS 6/6) or is it only RoHS compliant (RoHS 5/6)? If you have all lead free components (possible), and your raw PCB is lead free (RoHS 6/6) and your product is being assembled with lead free solder paste then you can have a fully lead free and 100% RoHS compliant product.

I hope this clears up any confusion on the issue of RoHS compliance but if there are any questions feel free to shoot me an note.

E