RoHS Roadmap

Why RoHS?

• Legislation: European Union has established a phase-out date of July 1, 2006 for Pb in electronic products with some exceptions.
• RoHS (Restriction on Hazardous Substances) and WEEE (Waste Electrical and Electronic Equipment ) directives prohibit the usage of Lead , Mercury, Cadmium, Hexavalent Chromium, PBB and PBDE.
• Customer requirement: Sony and other companies have initiated a green procurement process which required all suppliers to provide green product before certain deadlines.

Definitions

• Lead-free package

  • Lead-free package is ROHS compliance
  • Removal of lead (Pb) in package

• Green package

  • Removal of lead (Pb), antimony trioxide (Sb2O3) and brominated flame-retarding compound from encapsulants and substrates

• Maximum levels allowed

  • (Pb) < 1000 ppm
  • Halogens (Cl, Br) < 900 ppm
  • Antimony < 900 ppm

• Package Materials Impacted

Solutions

• Terminations

  • Lead plating from Sn-15Pb to Matted Sn.
  • Pre-plated lead frame (PPF) with Ni/Pd/Au finish.
  • Solder ball from Sn-37Pb to Sn-4.0Ag-0.5Cu or Sn-3.0Ag-0.5Cu, Sn-1.0Ag-0.5Cu

• Mold compound and Substrate

  • Moisture resistance for 260C reflow temp.
  • Phosphorous free
  • Halogens, Sb2O3 free. (Green package only)

Lead-free package Qualification

• Reliability Test Items:
  • Precondition:
    MSL Level III, 260 degree C
  • Temperature Cycle:
    -65℃~150℃/1000 cycles
  • High Temp. Storage:
    150/1000 hours
  • Temp Shock Test:
    -65℃~150℃/100 cycles
  • Pressure Cooker Test:
    121℃/100% RH, 15 PSIG, 168 hours.
  • Other Tests:
    Solderability, Lead finish composition, Whisker test, etc

Package Lead Free IR-Profile Samples

Figure Classification Profile

Nuvoton Lead-free and RoHS Marking Symbols

• We will print lead-free and RoHS symbol on bar code label to identification of lead-free assemblies.

FAQ

• How does Nuvoton define “lead-free”, “ROHS compatible” and “Green”?
  Lead-Free: Nuvoton's terms “ Lead-free” or ”Pb-free” mean semiconductor products that are compatible with current ROHS requirements for all 6 substances. Green: mean lead-free and free of Bromine (Br) and Antimony (Sb) based flame retardants.
• How can I find out if a specific device is lead-free or Green, or when it will be?
  Nuvoton product content website shows the current production status, package finish, and lead-free and Green status of the individual parts.
• Will lead-free or Green devices be more expensive than Pb-based devices?
  Pricing is determined by product marketing. Conversion to lead-free, in and of itself, is not planned to result in price changes.
• If a device is converted to lead-free, will Nuvoton continue to supply the Pb-based part?
  Nuvoton is encouraging all customers to convert to lead-free for all product use. Please contact with our sales for the special request of leaded products.
• Will Nuvoton change the part numbers?
  Yes, product part number will be changed for lead-free part.
• In what way would a lead-free or Green device influence my board’s functionalities or my application?
  None expected.
• Are lead-free parts compatible with a Pb-based soldering process?
  Our lead-frame based lead-free products are backward compatible with leaded soldering process. However, for BGA type lead-free products, it is not backward compatible with leaded soldering process. Solder joint reliability can be a concern.
• What is being done to mitigate tin whisker growth?
  We have chosen matte tin as the lead finish for all lead-free products. The package is annealed within 24 hours at 150°C for 1 hour after lead plating. This is the industry-accepted method for mitigating tin whisker growth.