In a complaint (Philips-Seoul-Complaint) filed last month in federal court in Santa Ana, California, Philips accused its Korean rival Seoul Semiconductor (Seoul) of infringing five patents relating to LED technology and asserted that one of Seoul’s “fundamental” semiconductor structure patents is invalid.
The Philips patents-in-suit are:
U.S. Patent No. 5,779,924, entitled “Ordered interface texturing for a light emitting device,” directed to an LED with a textured interface that improves light extraction;
U.S. Patent No. 6,274,924, entitled “Surface mountable LED package,” directed to an LED package with a heat sinking slug that is thermally isolated from the package’s metal leads;
U.S. Patent No. 6,547,249, entitled “Monolithic series/parallel LED arrays formed on highly resistive substrates,” directed to an array of LEDs wherein the p- and n- contacts are on the same side of the array and the individual LEDs are electrically isolated from each other by trenches or by ion implantation;
U.S. Patent No. 6,590,235, entitled “High stability optical encapsulation and packaging for light-emitting diodes in the green, blue, and near UV range,” directed to an LED component wherein the LED chip is encapsulatd by a rigid outer optically transmissive shell and an interior optically transmissive gel or resilient layer; and
U.S. Patent No. 6,717,353, entitled “Phosphor converted light emitting device,” directed to an LED device that includes a wavelength converting material Sr-SiON:Eu2+ which absorbs light emitted by the LED and emits light of a longer wavelength.
The accused products include Seoul’s Acriche, Top View, High Flux, Side View and Z-Power LEDs.
Philips is also seeking a declaratory judgment that its own products don’t infringe Seoul’s U.S. Patent No. 5,075,742 (’742 Patent) and that the ’742 Patent is invalid.
The ’742 Patent is entitled “Semiconductor structure for optoelectronic components with inclusions” and is directed to a structure having plural layers in semiconductor material. One of the layers includes stacked sub-layers, with each sub-layer having three dimensional “inclusions” – improved electron-hole areas – and a narrow band gap.
According to the ’742 Patent, this structure overcomes certain problems in production of ”III-V” semiconductors (so named for the columns of the Periodic Table in which the semiconductor materials are classified).
According to the complaint, Philips has a reasonable apprehension of being sued for infringement of the ’742 Patent because of a press releases and public statements by Seoul calling the patent “fundamental to indium gallium nitride-based light emitting device technology,” and characterizing a recent court decision as holding that it would be “impossible for LEDs that use InGaN in their active layers” to avoid infringement of the ’742 Patent.
The complaint also alleges that Seoul has threatened the “entire LED community,” and in discussions with Philips, specifically mentioned a European patent that is related to the ’742 Patent.
These are major LED players with big litigation warchests so this could turn into a major green patent war. This only a couple of years after Seoul wrapped up an epic LED patent battle with its Japanese competitor Nichia.
Eric Lane is a patent attorney at Luce, Forward, Hamilton & Scripps in San Diego and the author of Green Patent Blog. Mr. Lane can be reached at firstname.lastname@example.org.