Red Micro Wire Claims a Better Copper Wire
By David Lammers
The wire bonding industry is in the midst of a transition from gold to copper wires, often coated with palladium to avoid oxidation. Now, a company called Red Micro Wire claims it can cut costs and support scaling with a glass-coated wire which is cast, not drawn.
RMW uses a casting technique. (Source: RMW)
The wire used in wire bonding is a $6 billion market, said Danny Hacohen, director of business development at Red Micro Wire (RMW), which has operations in Israel and Singapore. Due to the high price of gold, the assembly industry is transitioning quickly to copper wires, which have good electrical properties but which often require a coating of palladium, itself a metal with a volatile price. While copper wires at 18-20 microns work well, scaling to the next-gen 14-15 micron diameter and below may be difficult, he said.
RMW has developed a semiconductor-use wire technology, based on wire-production ideas first created at an Israeli company called WNT. RMC CEO Shimon Dahan said Pd-coated copper is a good solution, but RWM’s wire will be 25-30 percent cheaper. “About 18-20 percent of a back-end operation is the material costs, so they are very eager to find something to reduce overall costs,” said Dahan, who earlier held senior positions at foundry Tower Semiconductor.
RWM’s wire is a cast wire, rather than a drawn wire. It is coated simultaneously with glass, with no diffusion between the glass and the metal core. “We use a glass sleeve mold, and the trick is to control the temperatures,” said Hacohen. While the initial mass market is for a glass-coated copper wire, the company also plans to supply niche markets with gold, silver, and platinum wires.
Besides cutting costs, Hacohen said RWM’s wire can be cast at smaller diameters than drawn copper wiring. Going beyond the 14-micron-diameter wire down the road will be “very complicated and very difficult” for conventional techniques, he said. Another advantage is that the glass-coated wires will not suffer from oxidation during storage, extending the shelf life. And the RMW reduces electrical shorts, he said.
The company shipped its first material in February from its Haifa, Israel facility, where the first casting tool is located. The tools are surprisingly small – only 3 by 2 meters in size – and can produce up to 25 kilometers of wire a month. RWM will sell wire, and does not initially intend to license its technology, as many startups do. Dahan said the company will not sell the tools either, at least according to current plans.
Shimon Dahan
Dahan said RWM is working with several customers, including an integrated semiconductor vendor which does both front-end and back-end operations, with more than $10 billion in annual revenues.
But chip-level reliability testing “is still in front of us. We have had no failures and no problems with the testing we have done, but chip-level reliability testing has yet to be completed,” Dahan acknowledged, adding that “it is not trivial to take a new wire and get it running.”
RMW is owned by Red Equipment, a secondary equipment vendor with 2011 revenues of about $50 million. “The experience we have had at Red Equipment gives us knowledge of the semiconductor market, including sales and service. We know how to work together with our customers to reduce costs,” Dahan said.
(Source: Red Micro Wire)
Tags: Assembly, copper wire, gold, Red Micro Wire, semiconductor manufacturing