Asahi Glass Co. v. Guardian Indus. Corp., Civ. No. 09–515–SLR.

886 F.Supp.2d 369

ASAHI GLASS CO., LTD. and AGC Flat Glass North America, Inc., Plaintiffs,

v.GUARDIAN INDUSTRIES CORP., Defendant.

Civ. No. 09–515–SLR.

United States District Court, D. Delaware.

Aug. 20, 2012.

Steven J. Balick, Esquire, John G. Day, Esquire, Lauren E. Maguire, Esquire and Andrew C. Mayo, Esquire of Ashby & Geddes LLP, Wilmington, DE, of Counsel, Michael D. Kaminski, Esquire and Liane M. Peterson, Esquire of Foley & Lardner LLP, for Plaintiffs.

Richard K. Herrmann, Esquire and Mary Matterer, Esquire of Morris James LLP, Wilmington, DE, of Counsel, Andrew M. Grove, Esquire of Honigman Miller Schwarz and Cohn LLP, for Defendant.

MEMORANDUM OPINION

SUE L. ROBINSON, District Judge.

I. INTRODUCTION

On July 15, 2009, plaintiffs Asahi Glass Co., Ltd. and AGC Flat Glass North America, Inc. (collectively, “plaintiffs”) filed a complaint against Guardian Industries Corporation (“defendant”) alleging infringement of plaintiffs' U.S. Patent Nos. 3,664,938 (“the '938 patent”) and 6,193,856 (“the '856 patent”) (hereinafter, collectively the “patents-in-suit”). (D.I. 1) A jury trial on the validity of claim 16 of the '856 patent and claims 1, 3–4, 7–11, 18–20 and 25 of the '938 patent was held between October 17 and 21, 2011. Following a verdict of validity, judgment was entered for plaintiffs. (D.I. 225, 230) Presently before the court are defendant's renewed motion for judgment as a matter of law (“JMOL”) and motion for a new trial, as well as defendant's arguments to the court on the issue of inequitable conduct. (D.I. 233, 235) The court has jurisdiction over these matters pursuant to 28 U.S.C. § 1338.

II. BACKGROUNDA. Technology Overview

This case involves technology for applying thin film coatings to glass. One popular metallic coating, titanium dioxide, is highly refractive and also imparts “antibacterial, antifouling or drip flowing” properties to glass. ('856 patent, col. 13:33–37) Coatings are not applied directly onto glass. Rather, a “sputtering” process is employed. Generally, sputtering involves bombarding a sputtering target with charged ions. Metallic atoms from the target (the “target material”) are displaced and fall to the surface of a sheet of glass passing below the target. This process of displacing atoms from the sputtering target is analogous to using a cue ball to hit a billiard ball. The result is a thin metal oxide film being deposited on the glass surface.

Sputtering targets may be made by several processes, such as sintering and plasma spraying. Sintering involves creating a target by placing a powder form of the target in a mold and subjecting it to heat and pressure. By this process, the powder solidifies into a mass that becomes the target. Plasma spraying, as its name implies, involves heating and spraying powder material onto a target substrate where it solidifies and hardens. Semi-molten powder particles are coated onto a substrate (such as a cylindrical tube) in layers until the desired thickness is achieved.

B. Patents–in–Suit

The '856 and '938 patents are related as parent and continuation applications; they have a common specification. Both patents are entitled “target and process for its production, and method for forming a film having a highly refractive index.” The '856 patent was filed on March 12, 1998 and claimed priority to a PCT application (PCT/JP96/00767) filed March 25, 1996 which, in turn, claims priority to Japanese application JP7–215074 (“JP–074”) filed August 23, 1995. The '938 patent was filed on December 5, 2000 as a continuation of the application issuing as the '856 patent. The '856 patent issued on February 27, 2001 and the '938 patent issued on January 1, 2002.

The patents teach that excellent optical properties are imparted to glass by employing both a high refractive index film and a low refractive index film; the larger the difference between the two, the better the result. ('856 patent, col. 1:33–36) Direct current (or “DC”) sputtering is “most suitable for forming a film over a large area” of glass. ( Id., col. 1:49–51) Reactive (DC) sputtering is a process whereby a metallic target having electroconductivity is subjected to sputtering in an atmosphere containing oxygen. Reactive sputtering has certain pitfalls, such as poor productivity and high cost. ( Id., col. 1:53–60)

The inventors provide an “electroconductive sputtering target which can be formed into any desired shape and which is capable of forming a high refractive index film at a high speed by DC sputtering, a process for its production, and a method for forming a high refractive index film using such a target.” ( Id., col. 2:56–61) The target material of the invention comprises a metal oxide of the formula MOx as the main component, where M is selected from the group consisting of Ti (titanium), Nb (niobium), Ta (tantalum), Mo (molybdenum), W (tungsten), Zr (zirconium) and Hf (hafnium). Importantly, the metal oxide is deficient in oxygen as compared with the stochiometric composition. ( Id., col. 2:64–col. 3:4) Thus, when M in MOx is Mo and/or W, x is preferably within the range of 2< x <3. ( Id., col. 3:19–21) When the metal is selected from the group consisting of Ti, Zr and Hf, x is preferably within a range of 1< x <2. ( Id., col. 3:21–24) As a comparative example, stochiometrically-balanced titanium oxide has the molecular formula TiO2. The sub-stiochiometric targets of the patents (TiOx) may have the formula TiO1.80 or TiO1.90.

The patents refer to the advantages of these formulas.

By using the sputtering target of the present invention, a transparent film having a high refractive index can be formed at a high speed by DC sputtering ... [and] a film having a high refractive index can be produced at a high speed and under a stabilized condition.

( Id., col. 13:13–21) The targets are easily produced in a variety of shapes and resist thermal shock, cracking and breakage when high sputtering power is imparted, thus increasing productivity. ( Id., col. 13:22–27, 13:38–45)

1. Sputtering target claims

This case involves both what the parties refer to as “sputtering target claims” ('856 patent claim 16 and '938 patent claims 10–11 and 18–20) and “film forming claims” ('938 patent claims 1, 3–4 and 7–9). Claim 16 of the '856 reads as follows.

16. A sputtering target comprising a substrate and a target material formed on the substrate, wherein

the target material comprises as a main component an oxygen deficient oxide;

the oxygen deficient oxide comprises at least one metal oxide of a chemical formula TiOx that is deficient in oxygen as compared with a stoichiometric composition of the at least one metal oxide; and

1< x <2.

Independent claim 10 of the '938 patent is also directed to sputtering targets, and claims as follows.

10. A sputtering target comprising

a substrate;

a target material formed on the substrate; and

an undercoat of a metal or alloy between the target material and the substrate, wherein

the target material comprises as the main component an oxygen deficient oxide;

the oxygen deficient oxide comprises a metal oxide of a chemical formula TiOx that is deficient in oxygen as compared with a stoichiometric composition of the metal oxide; and 1< x <2.

Claims 11 and 18–20 of the '938 patent depend from claim 10 and add the additional limitations of a specific thermal expansion coefficient for the target material's undercoat (claim 10), target material thickness (claim 18) and target resistivity (claims 19–20).

The patented sputtering targets have three layers: (1) a substrate, or inner layer; (2) an undercoat, or middle layer; and the (3) target material, or the outer layer. The patents provide that the substrate may be “various metals or alloys” such as “stainless steel, copper or titanium.” ( Id., col. 4:58–59) The undercoat may be made of an electroconductive powder of several metals or metal alloys,¹ and preferably has a thickness from 30 to 100µm. ( Id., col. 5:21–25) The undercoat reduces the thermal expansion between the target material to be sprayed and the substrate. ( Id., col. 5:1–5) The material for the undercoat must be changed depending upon the thermal expansion coefficient of the ceramic (target material) layer. ( Id., col. 5:26–28)

2. Film forming claims

Claim 1 of the '938 patent is directed to a film forming method, as follows.

1. A method for forming a film, the method comprising sputtering a target, wherein

the sputtering target comprises a substrate and a target material formed on the substrate;

the target material comprises as the main component an oxygen deficient oxide;

the oxygen deficient oxide comprises a metal oxide of a chemical formula TiOx that is deficient in oxygen as compared with a stoichiometric composition of the metal oxide; and 1< x <2.

Claims 3–4 and 7–9 depend from claim 1 and further limit the claim so as to require specific target resistivities (claims 3–4), that the sputtering occur in an argon-containing atmosphere (claims 7–9) and that the film has a specific refractive index (claim 9).

The specification provides that a “uniform transparent film can be formed at high speed when sputtering is carried out by using the target of the present invention in an argon atmosphere or in a mixed atmosphere of argon and a small amount of [oxygen] under a pressure of from 1 x 10 ^–3 to 1 x 10 ^–2 Torr.” ( Id., col. 6:31–35) There is no need to introduce an excessive amount of oxygen gas (relative to the metal atoms) as with other targets and, therefore, the invention reduces the deposition of oxygen atoms on the target surface, thereby reducing deterioration and increasing the film forming speed. ( Id., col. 6:43–67)

C. Procedural Posture

The resolution of the pending motions will be facilitated by a review of the procedural history of this litigation. In response to plaintiffs' allegations of infringement, defendant originally brought declaratory judgment counterclaims of noninfringement and invalidity under “35 U.S.C. §§ 101, 102...