Green

1
Green ( robust)
2
Regulation

• Europe RoHS (Directive 2002/95/EC on the
  restriction of the use of certain hazardous
  substances in electrical and electronic
  equipment) since 1/7/2006
• - Its aim is simple to restrict the use of
  six substances within electrical and electronic
  equipment (EEE), in order
• - to contribute to the protection of human
  health and the environment
• http//www.dti.gov.uk/sustainability/pdfs/finalroh
  s.pdf
• USA nothing at the moment

3

• Proposed Maximum Concentrations
• - Lead Pb 0.1
• - Mercury Hg 0.1
• - Cadmium Cd 0.01
• - Hexavalent Chromium Cr (VI) 0.1
• - Polybrominated biphenyls PBB 0.1
• - Polybr. diphenyl ethers PBDE 0.1

4

• Some companies use(d) tin/lead solder (plating)
  for the surface finish of leadframes. These
  packages are deemed as "leaded."
• SnPb is a commonly used solder paste
• -gt two problems
• - remove these materials from the ICs
• - higher soldering temperatures

5

• By using a lead-free solder paste, higher
  temperatures than for SnPb-solder are required
• Use of a new lead plating material has
  necessitated the use of different mold compounds
  and die attach epoxies that will maintain equal
  or improved device package integrity when solder
  temperatures of 260-degrees C are used for
  processing the newly plated devices.
• The vapor pressure of moisture inside a plastic
  package can cause damage when the package is
  exposed to the high temperature of solder reflow
  (Moisture Sensitivity Level MSL).
• The new mold compounds are referred to as Green
  mold compounds.
• In addition to addressing higher temperature
  soldering conditions and maintaining acceptable
  moisture sensitivity levels they also eliminate
  other hazardous elements/compounds, such as those
  used to enhance flame-retardance.

6
Lead-free

• For some integrated circuits manufacturers, lead
  is the only RoHS-banned substance of concern
• (other manufactures also use other restricted
  materials in the terminations and substrate
  materials or mould compounds)
• In this case, lead-free products are also RoHS
  compliant products.
• Often (e.g. Maxim, Linear Tech.), lead-free
  packages have a surface finish that is comprised
  of 100 matte tin.

7
Lead-free

• Matte Tin terminal finish can be soldered very
  well at 240C to 250C, and is compatible with
  SnPb and SnAgCu solder paste
• The selection of Matte Tin (100 Sn) plated and
  annealed leads has been established as the
  solution toward the elimination of Pb in the
  plating process for all leaded package devices.
• For ball grid array (BGA) devices, which had
  63Sn/37Pb, a change to 95.5Sn/4.0Ag/0.5Cu
  solder balls has been selected.

8
WEEE Directive 2002/96/EC

• Another rule is the Directive 2002/96/EC of 27
  January 2003 on waste electrical and electronic
  equipment (WEEE)
• which aims at recycling devices and their
  components
• http//www.dti.gov.uk/sustainability/pdfs/finalwee
  e.pdf
• the producer has the duty to finance the
  operations of collection, stock, transport,
  recycling and correct disposal of the devices,
  once their live has come to the end