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Federal Circuit rejects narrow approach to relation back doctrine

The U.S. Court of Appeals for the Federal Circuit, the appellate court that hears all patent-related appeals, recently revived an infringement lawsuit based on the relation back doctrine. The court found the trial court’s application of the doctrine, which resulted in the case being dismissed because of the statute of limitations, “overly restrictive.”

The charges

Anza Technology holds a patent that describes tools for bonding electronic components to substrates and printed circuit boards using techniques known as “wire bonding” or “flip-chip bonding.” The patent claims in question, however, only cover the flip-chip bonding technique.

Anza sued Mushkin, Inc., alleging patent infringement of the flip-chip bonding claim. After Mushkin provided a declaration that its products didn’t use the bonding technique, it filed a motion to dismiss the case. Anza agreed, and the trial court granted the motion but allowed Anza to file an amended complaint.

The company’s amended complaint removed reference to the original patent and alleged infringement of two new patents that covered wire bonding techniques. The new complaint included six of the 16 products accused of infringement in the original complaint and added two new products.

Mushkin filed another motion to dismiss, arguing the amended complaint didn’t relate back to the date of the original complaint, and the district court again granted it. The court ruled that new claims of infringement don’t relate back if:

  1. They aren’t an integral part of the claims in the original complaint, and
  2. Proof of the new claims won’t entail the same evidence as proof of the original claims.

Finding that to be the case here, it concluded that the infringement claims in the amended complaint were barred by the statute of limitations.

The appeal

Anza appealed, arguing that the relation back doctrine did apply. Under the doctrine, an amended complaint relates back to the date of the original complaint if the amendment asserts a claim or defense that arose out of the same conduct, transaction or occurrence set out — or attempted to be set out — in the original pleading.

Interpreting the doctrine liberally, the U.S. Supreme Court has deemed it applicable if the amended complaint relates “to the same general conduct, transaction and occurrence” as the original complaint. The Court reasons that a party who has been notified of litigation about a particular occurrence has received all of the notice that statutes of limitations are intended to provide.

After reviewing the history of the relation back doctrine, the Federal Circuit concluded that the relevant considerations for determining whether newly alleged claims, based on separate patents, relate back are:

  • The overlap of parties,
  • The overlap in the accused products,
  • The underlying science and technology,
  • Time periods, and
  • Any additional factors that might suggest commonality, or lack thereof, between the two sets of claims.

Ultimately, it said, the question is whether the general factual situation or the aggregate of operative facts underlying the original complaint gave Mushkin notice of the nature of the allegations against it.

The Federal Circuit found that the parties in the two complaints overlapped completely, while six of the products overlapped. The patents all shared the same underlying science and technology, despite covering different bonding techniques, and the time period in the second complaint fell wholly within the time period in the first.

A lawsuit rebooted

The Federal Circuit held that the claims in the second complaint regarding the six originally accused products related back to the date of the original complaint and reversed the motion to dismiss them. It also vacated the dismissal of the claims addressing products added in the amended complaint and remanded them to the trial court to determine whether they related back in light of the legal standard described above.


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