| We
have been supporting one of our large customers’ engineering operations
by producing lead-free prototypes in our San Diego NPI center since January
2004. Our sister operation, Total Electronics, has assembled a lead-free
implementation team which includes a staff engineer with a Ph.D. in this
aspect of materials sciences. They have currently have the capability
of producing lead-free surface mount assemblies and are planning to transition
their first customer program to lead-free in Q2 2005.
While there are a number of considerations in the move
to lead-free electronics, some of the most important are:
- Lead-free
reflow and wave soldering temperatures are significantly higher than
for tin-lead products. Because of this, many existing parts are not
compatible with lead-free production unless they are moved to a manual
assembly process.
- Many components
are not yet available in lead-free packaging. For these two reasons,
it is virtually a requirement to re-design any product that is moving
to lead-free. In doing this, it is an opportune time to move to 100%
SMT packaging (or at least limit through-hole technology to intrusive
reflow). We are prepared to work with our customers to re-design their
products to fit into the lead-free environment.
- Some component
manufacturers are not changing part numbers when they transition to
lead-free materials. This will make tracking very difficult. We, and
the IPC, are encouraging all suppliers to change part numbers. Either
way, our customers will need to make significant changes in their
AVLs. We are prepared to assist in this effort and have strong partnerships
with our supplier-partners in this area.
- Lead-free
products may have a grainy solder appearance normally associated with
cold solder joints in the past. There are likely to be more voids
and opens with lead-free soldering, and more exposed copper on pads.
The IPC is releasing new standards for quality for lead-free products.
Our teams will continue to stay abreast of new standards development.
In Europe, the Restriction of the use of certain Hazardous
Substances in electrical and electronic equipment (RoHS) states:
"Beginning 1 July, 2006, new electrical and electronic equipment
put on the market shall not contain lead, mercury, cadmium, hexavalent
chromium, polybrominated biphenyls (PBB) or polybrominated diphenyl
ethers (PBDE)."
There is some debate as to whether lead-free solder
joints are less reliable in large temperature ranges. For this reason,
it appears that the automotive, medical (implanted and infected products),
IT/Telecommunications servers, large scale stationary industrial tools
and aerospace/military sectors will initially be exempt from the July,
2006 European mandate. Spare parts are exempt. The requirement is placed
on any company selling products under their name into Europe and it
should be noted that hazardous substance restrictions go beyond elimination
of lead alone. In addition, there is a similar requirement already in
existence in Japan.
The overall price premium for lead-free SMT assemblies is between 5%
and 10%; and somewhat higher for through-hole assemblies. However, by
re-designing products simultaneously, it is likely that the price premium
can be avoided or at least reduced.
Currently, we have customers wishing to take surface mount products
to lead-free in 2005, and we are supporting those efforts. Generally,
our customers are re-designing their products as they make this move
and usually working to eliminate wave soldering requirements.
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