IXYS wins reversal in patent dispute

Electronic News, June 30, 1997

In a decision earlier this month, the U.S. Court of Appeals for the Federal Circuit found fault in a summary judgement by the U.S. District Court that IXYS' IGBTs infringed Harris Corp.'s U.S. patent 4,364,073 ('073) and overturned earlier rulings as to the validity of the patent. The court in San Francisco was ordered to take another look at the issue in light of the higher court's opinion.

Harris argued that its '073 patent, "Power MOSFET with an Anode Region" for the design of a high-voltage IGBT, is fundamental for the invention of the IGBT. Earlier this year, the district court agreed and awarded Harris $3.66 million in damages and interest (EN, March 10). The appellate court questioned such a sweeping interpretation of the patent, which would have covered IXYS' entire line of IGBTs.

IGBT power semiconductors are used to switch current and reduce energy consumption in electronics equipment like AC drives and motors. The devices are considered important in the development of electric cars with performance matching that of gasoline-powered autos.

Harris Semiconductor, a subsidiary of the giant Melbourne, Fla.-based Harris Corp., is a major supplier of all types of power semiconductors, including power MOSFETs and intelligent power ICs. IGBTs represent less than 5 percent of Harris' overall power semiconductor sales but, at $60 million revenues in 1995, was still greater than IXYS' total company revenues.

IXYS said that the reversal of the ruling "cast a cloud of uncertainty over Harris' role in the industry." Harris, which claims to have invented the IGBT, has licensed its technology to a number of power semiconductor suppliers, although the company declined to name licensees or break out revenue from royalties.

While IXYS suggested licensees may do well to re-examine the value of such arrangements, Harris insisted the ruling will not affect existing license agreements.

"This affects only one IGBT patent Harris owns in a broad portfolio of IGBT patents. Companies that license IGBT technology are licensing an entire portfolio, not just one patent. However, this decision doesn't resolve all issues concerning the patent and, we are looking at what action to take from here," a Harris spokesman said.

As far as IXYS is concerned, the case is over, said Arnold Agbayani, CFO of the Santa Clara, Calif.-based company.

"This has been a thorn in our side for the last three years," he said. "It is uncomfortable for a company the size of IXYS to be sued by a company the size of Harris. The compulsion to settle--even though we firmly believed we did not infringe their patent--was very strong." IXYS said it did in fact offer a settlement, which Harris refused, choosing instead to bolster its position in court.

"In the end, this lawsuit has forced us to examine our technology position and possibly enforce our own portfolio of patents," said Mr. Agbayani.