Motion re Intervening Rights Denied, Lam Research Corp. Micro Inc. v. Schunk Semiconductor, et al., Case No. C 03-1335 (Judge Edward Chen)

The Patent Office's reexamination and post-grant review procedures have generated a lot of discussion lately.  But a recent order in the Lam Research case shines the spotlight on their older and somewhat less divisive sibling procedure, the reissue.  Lam Research obtained a reissue of one its patents in litigation to fix a claim that had been previously impossible to infringe.  Defendant Xycarb, which is owned by Schunk, argued that Lam's correction nullified its infringement case because Xycarb had acquired intervening rights with respect to the reissued patent.  Judge Chen disagreed and concluded that the reissued claim was "substantially identical" to the original version of the patent claim, based on a review of the specification, the nature of the correction, and prosecution history.

In December of 2003 Lam requested reissue for one of its patents.  Reissue allows for correction of defective claims, provided the patent issued with an error and the applicant acted without deceptive intent.  Lam sought to correct one of its claims by changing the following language: "wherein the material of the electrode plate support ring has a higher coefficient of thermal expansion than that of the electrode plate."  The patent office allowed the correction.

Xycarb argued that it was no longer liable for infringement because the reissue gave Xycarb absolute or equitable "intervening rights" to make, use and sell its accused products.  Intervening rights protect a party whose previously lawful activity becomes infringing when a patent's claims change.  "Absolute" intervening rights totally protect a party's activities that occur before the change in the patent claim.  "Equitable" intervening rights allow a judge, at his or her discretion, to mitigate liability for a party whose infringing activity occurs after the change in patent claims if the party made substantial preparations for the infringing activities before the patent changed.

Intervening rights do not accrue, however, if the reissued claims are substantially identical to the original claims.  A change that clarifies the claim without changing its scope meets the "substantially identical" standard.

Judge Chen held that the reissue merely fixed a typographical error.  The original claim stated:

wherein the material of the electrode plate has a higher coefficient of thermal expansion than that of the electrode plate.

Judge Chen determined this was a drafting error because the patentee obviously did not intend to compare with electrode plate with itself.  The specification also supported the reissued claim's substitution, which required comparing the "support ring" with the "electrode plate" because the specification stated that the support ring should have a higher coefficient of thermal expansion than the electrode plate.

Xycarb argued that Lam's change was in fact substantive because the claim attempted to recapture material Lam surrendered during examination.  Xycarb relied on a rejection during prosecution in which the examiner had written that "Shigeru teaches bonding the backing plate to an electrode plate (silicon dioxide) at elevated temperature . . . wherein the material of the electrode plate (Cu) has a higher coefficient of thermal expansion than that of the electrode plate (silicon dioxide)."  But Judge Chen found that the examiner had misspoken, and that in any event, that passage in the Shigeru reference did not actually relate to the electrode plate at issue in the Lam litigation.

As Lam Research shows, reissue is a powerful (albeit somewhat infrequently used) procedure available to patent owners.  Judge Chen's latest Order shines a light on some of its practical curative effects, and undoubtedly brightened the patentee's day.

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