Intel has shipped its first lead-free memory chips last year. The new chip packages use lead-free solder balls. Intel is working with the industry to find a reliable solution for the tiny amount of lead still needed inside the processor packaging to connect the actual silicon "core" to the package.
The transition to lead-free is a massive industry-wide effort with many technological, logistical and economic challenges. Since 2000, Intel has been working with industry consortia and the European Union's Restriction of Hazardous Substances (RoHS) legislation committee to come up with a solution that can be used around the world. To achieve this, the company developed reference procedures on its own research assembly lines to aide customers implement lead-free technology in their manufacturing process.
"Intel shipped millions of lead-free Flash Memory components in 2003. Today's announcement is the next major step on the road to a lead-free product line for Intel's high volume CPU and chipset product lines," said Nasser Grayeli, Intel vice president and director of assembly technology development, Technology and Manufacturing Group. "Our goal has been to develop a total solution that addresses the needs and concerns of our customers and suppliers, from the package materials to motherboard manufacturing. By doing this, our customers will be able to launch platforms with the new lead-free technology in the second half of 2004."
Getting the Lead Out
Lead has been used in electronics for more than one hundred years because of its electrical and mechanical properties. It has been a scientific and technical challenge for industry researchers to develop new materials that meet the performance and reliability requirements for the different ways lead is used in components, products, and assembly processes. At the same time, various national bodies around the world have been working to reduce or eliminate lead and therefore the danger it represents to the environment and general health.
Intel qualified its first lead-free Plastic Ball Grid Array package in 2001 for use with its Flash memory, and shipped its first lead-free product in 2002. The lead/tin solder previously used for connecting this package to the motherboard was replaced with a tin/silver/copper alloy. This work allowed Intel and its customers to gain valuable insight about what was required both technologically and logistically to make the transition to lead-free technology.
Intel's new Flip Chip Ball Grid Array package (Figure 1) also uses a tin/silver/copper alloy to connect the chip package to the motherboard. However, until Intel and the industry can certify a replacement that meets performance and reliability requirements, a tiny of amount of lead/tin (about .02 grams) is still used inside the sealed package to attach the silicon core to the package.
Intel used its assembly development lines in Arizona and Oregon, and Malaysia facilities to perfect both flip chip packages and printed circuit board assembly (PCA). The new lead-free compatible materials and assembly processes were documented as reference processes for distribution to customers and system manufacturers.
This gave customers a reference point to start redesigning their own printed circuit board assembly processes and bring them into alignment with the lead-free solution. Intel will continue to ship processors with the current packaging during the transition period to aid system manufacturers who need time to develop and qualify their lead-free processes and products.