ROHS

RoHS Directive(2002/95/EC)

The restriction of the use of certain hazardous substances in electrical and electronic equipment

RoHS Directive(Objective)

To restrict the use of hazardous substances in electrical and electronic equipment and to contribute to the protection of human health and the environment.

RoHS Directive(Scope)

• EEE falling under the categories 1-7 and 10 in WEEE Directive annex IA
  1〉Large household appliances
  2〉Small household appliances
  3〉IT and telecommunications equipment
  4〉Consumer equipment
  5〉Lighting equipment
  6〉Electrical and electronic tools (with the exception of large-scale stationary
  7〉industrial tools)
  8〉Toys, leisure and sports equipment
  9〉Automatic dispensers
• and electric light bulbs and luminaries in households
• Only apply to new products placed on the market after 1 July 2006.
• It does not apply to spare parts for the repair, or to the reuse, of electrical and electronic equipment put on the market before 1 July 2006.
  

RoHS Directive (Restricted Substances)

• RoHS restricts a total of six substances:
  - Lead
  - Mercury
  - Hexavalent Chromium
  - Cadmium
  - Polybrominated Biphenyls (PBB)
  - Polybrominated Diphenyl Ethers (PBDE)
• The maximum concentration value not to be confirmed, but mostly to be
  - 0.1% by weight per homogeneous material for lead, hexavalent chromium, mercury, PBB and PBDE
  - 0.01% by weight for Cadmium

RoHS Directive (Exemptions)

• Exemption of the EEE of the application of lead, mercury, cadimum and hexavalent chromium (Annex of RoHS Directive)
• 10 categories EEE in the exemption list.

RoHS Directive (Time Schedule)

• 13 Aug 2004, transposed into law
• 13 February 2005, reviewed by European Union Commission
• 1 July 2006, come into effect

What does Topsearch do?

• When can Topsearch starts delivering printed circuit boards that comply with RoHS?
• As the materials that Topsearch uses already comply with RoHS, the crucial factor is the surface of the circuit board. We have OSP, ENIG, Immersion Silver which are comply to RoHS guidelines.
• What base material does Topsearch use?
• Topsearch uses base materials that already correspond to RoHS guidelines. Tetrabromobisphenol A acts as a flame retardant in FR4 laminates (CAS no.: 79-94-7), in compliance with RoHS.
  

Laminate / Prepreg for lead-free application

Two concerns with higher soldering temperatures are the z-axis expansion and decomposition of the laminate.

Higher soldering temperatures result in higher levels of z-axis expansion, which may affect PTH reliability.

Decomposition, or breaking of polymeric bonds, happens during high-temperature soldering. Although tests are conducted regularly for laminate, which calls for the materials to survive a steady 288° C temperature for 15 to 20 minutes, mere seconds during a soldering operation could break polymeric bonds within the material.

Although the polymeric bonds broken will most likely be a very small percentage (i.e., 3 to 5 percent), one should consider this from a reliability standpoint the same as breaking a few cables on a suspension bridge. The results of small bond breakage could lead to moisture inclusions and even poor Tg.

Halogen-free Laminate / Prepreg available in Topsearch

Halogen-free solder mask and legend ink

Surface Finishing Available

• OSP: ENTEK Cu-106A, Glicoat L2(FX)
• ENIG
• Immersion Silver (Sterling)
• Immersion Tin