IBM turns wafers into solar panels

Aims to repurpose around three million discarded silicon wafers yearly

Ian Williams, vnunet.com 31 Oct 2007

IBM has developed a semiconductor wafer reclamation process that turns scrap wafers into silicon-based solar panels.

Big Blue claimed that the new process allows it to more efficiently remove the imprinted circuitry from the wafer surface.

This makes the wafers available for sale to the solar cell industry, which is seeing an increasing demand for the same silicon material for use in solar panels.

These repurposed wafers can also be used in internal manufacturing calibration as 'monitor wafers'.

"One of the challenges facing the solar industry is a severe shortage of silicon which threatens to stall its rapid growth," said Charles Bai, chief financial officer at ReneSola, one of China's fastest growing solar energy companies.

"This is why we have turned to reclaimed silicon materials sourced primarily from the semiconductor industry to supply the raw material our company needs to manufacture solar panels."

Electronics manufacturers use silicon wafers as the starting material for manufacturing microelectronic products, from mobile phones to computers to consumer electronics, and to monitor and control the myriad steps in the manufacturing process.

The Semiconductor Industry Association reported recently that 250,000 wafers are started every day across the global IT industry.

IBM estimates that up to 3.3 per cent of these are scrapped, amounting to approximately three million discarded wafers every year.

Most of the wafers cannot be sent to outside vendors to reclaim because they contain intellectual property via the imprinted electronics. They are generally crushed and sent to landfills, or melted down and resold.

Depending on how solar cell manufacturers choose to process a batch of reclaimed wafers, IBM estimates that they could save between 30 and 90 per cent of the energy needed if they had used a new silicon material source.

IBM intends to provide details of the new process to the broader semiconductor manufacturing industry.

The process was recently awarded the '2007 Most Valuable Pollution Prevention Award' from The National Pollution Prevention Roundtable.

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