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- What is Aavid's approach to the RoHS and Lead-Free issues?
Aavid Thermalloy's RoHS policy is described in its RoHS specification, RoHS-9000. It generally sets the same limits for the six RoHS
substances as currently specified by the EU legislation. It also bans asbestos and the use of ozone-depleting substances.
- What is Aavid Thermalloy's timetable for making its products compliant?
Two-thirds of our standard catalog products are already compliant and always have been. For those that are not compliant, the most common issue is the lead that has been part of the tin-lead solder plating on solderable mounting features such as pins and tabs on board-level heat sinks.
We plan to begin conversion of these products to compliant versions beginning in March, 2005.
- What will replace the tin-lead plating in the standard products?
The new plating will be 100% matte tin with a nickel barrier layer between the tin and the base material.
- What about solderability of the new plating?
Testing in Aavid's Thermal Lab has shown that the new plating passes IPC/EIA/JEDEC J-STD-002 solderability for both eutectic tin-lead solder (63/37) as well as tin-silver-copper solder when used with a mild no-clean liquid flux.
We regard our plating recipe as both backward- and forward-compatible with the primary soldering processes. As always, we recommend that our customers test for acceptability in their process.
- How do Aavid's standard heat sinks deal with the elevated soldering temperatures used with the new lead-free solders?
For the majority of our heat sinks, the higher temperatures are not an issue since they are 100% metal. Some copper substrate heat sinks are painted black with either polyurethane or epoxy paint; if you plan to use these at the higher temperatures associated with lead-free solders, please contact your Aavid distributor regarding sample quantities for testing in your process.
- Are there moisture sensitivity issues with your standard products?
No
- Since your plating recipe uses 100% tin, what about tin whiskers?
Aavid's plating recipe, 100% matte tin over a nickel barrier layer, follows the standard industry approach to whisker mitigation. We understand that whiskers typically occur when tin plating directly contacts a copper or copper alloy substrate,
which then diffuse into each other, forming tin-copper intermetallic. This sets up compressive forces in the plane of the plating, causing 'extrusion' of tin whiskers. We believe industry testing has shown that a nickel barrier layer significantly reduces intermetallic formation and thus prevents whiskers. Further, most applications of our board level heat sinks are for power devices that do not have fine-pitch connections that are the primary concern regarding whiskers.
- Will the part numbers change for new RoHS compliant products?
Yes. To differentiate RoHS compliant products, Aavid Thermalloy has added a "G"suffix to all part numbers that meet the RoHS 9000 specification.
Example:
576802B03100 = Non-Compliant P/N
576802B03100G = New RoHS Compliant P/N
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