Q. What date has been set for RoHS directive to become activated?

Answer: Product arriving in EU on July 1, 2006 shall be in compliance with RoHS directive.

Q. What comprises a Lead-Free Assembly to meet RoHs and WEEE?

Answer: The Components, PCBs and the Assembly Process must not contain lead greater then .1 percent. Additionally, components or the entire assembly must not contain any of the listed group of chemicals such as PBB and PBDE and metals such as Hexavalent Chromium, cadmium and mercury.

Q. Are lead-free devices compatible with conventional (Sn/Pb) soldering processes?

Answer:  In most cases the answer is “Yes.” Full forward / backward compatibility should be ensured by performing a complete review of components listed on a BOM (Bill of Materials). Lead-free devices have either pure tin or NiPdAu (Nickel, Palladium & Gold) plating. Note: one exception will be BGA’s and BGA style packages. Standard Sn63 reflow temperature is too low to allow for proper melting of the higher temperature SAC (Tin, Silver & Copper) alloy used for solderballs on BGA’s and BGA style packages.

Q. Will device part marking change? What will distinguish RoHS / Pb-free products from current SnPb finish products?

Answer: The answer is “Yes” and “No.’  Many companies are planning to have the new RoHS / Pb-free finish devices completely replace those currently offered with tin-lead. Once a product is converted, it will only be available with a RoHS / Pb-free finish. Since there will be no difference in form, fit or function and the parts will be qualified for either solder reflow manufacturing process, once the conversion is complete there will be no distinction in the product marking. The only distinction will be the manufacturing date code. Other companies will identify their RoHS/Pb-free products with a unique part number to easily identify from tin-lead components.

Q. Will board laminate material be required to change for Pb-free assembly process?

Answer: Pb-free soldering process has a much higher reflow temperature than standard tin-lead process. Laminates such as standard FR4, used mostly in tin-lead assemblies, will not be adequate to support Pb-free processes. Many individuals may suggest moving from a standard FR4 with a Tg (transitition to glass) of 145 degrees C to a laminate rated at 180 Tg. The Tg is no longer meaningful when we consider Lead-Free solder. We now worry about the degrading of the material and how much heat it can withstand over a period of time. This is identified as Td (temperature to decomposition). 

Q. Do all laminate suppliers have material that will meet Pb-free requirements?

Answer: Virtually all laminate suppliers have various products that should meet everyone’s requirements. We do not endorse any one laminate manufacturer. Polyclad 370 HR is one product that appears to be getting more attention than others.

Q. Do I need to purchase a Halogen Free laminate to meet RoHS directives?

Answer: No! There is no requirement to force use of Halogen Free laminates. These laminates are available but are generally more expensive and provide no added benefit.

Q. What type of surface finishes are available on bare boards? Are all surface finishes the same?

Answer: The list below provides detail on commonly acknowledged surface finishes. Currently ENIG and Immersion Ag (Silver) are the most widely used. Schippers & Crew, Inc. currently recommends use of ENIG finish.