Noted author and futurist Ray Kurzweil wrote back in 2001, "We won’t experience 100 years of progress in the 21st century — it will be more like 20,000 years of progress. . . ."
From the invention of the first integrated circuit in 1958, technology has evolved at an unbelievable rate, and, as Kurzweil suggests, that won't be changing any time soon. Though several factors contribute to this rapid rate of change, temporary bonding is undeniably an integral part of the evolution and future of nanotechnology.
Generally speaking, temporary bonding is the process by which an ultrathin substrate is attached (usually by some sort of adhesive) to a thicker carrier substrate. This approach allows us to process these ultrathin wafers without breaking or bending them in their fragile state. But there’s another side to this story, and it’s one that presents a unique set of challenges.
Although the bonding process seems straightforward, it’s the debonding process that has caused some headaches in the microelectronics industry. For example, one process we’ve been using is a thermal release system, which involves heating both wafers, “melting” the adhesive, and then carefully sliding the two wafers apart. After a quick chemical rinse to remove the remaining adhesive, they are good to go.
The challenge arises not necessarily in the process, but in the adhesives used during debonding. When exposed to the high heat necessary for debonding, certain adhesives have a tendency to delaminate and form a bubble of adhesive vapor. This, of course, is not good. The bubbles could decrease the integrity of the thinned wafer or even cause enough stress to fracture it. The solution to this issue comes from developing an adhesive that can withstand the high temperatures needed for the thermal release process.
At Brewer Science, we’ve created a bonding material called BrewerBOND® 220 material that is not only stable up to 250°C (482°F) but also allows a higher throughput than some other processes with a debonding time of less than 5 minutes. This material even protects the wafer edges and circuitry and can work on a large array of bonders. As a result, wafer processing is more seamless than ever before and takes less time.
Our offerings don't just stop at bonding and debonding. Brewer Science's patented materials and processes can help put you at the forefront of your industry — the same way we're at the forefront of ours. Contact us today to learn more.