Federal Circuit’s X2Y Attenuators Decision Reinforces The Importance Of Drafting Patents For Litigation
On July 7, 2014, the Federal Circuit Court of Appeals issued an opinion in X2Y Attenuators, LLC v. International Trade Commission, which underscores the importance of carefully drafting patent applications with an eye toward litigation. The decision also demonstrates why form often dominates over substance in patent litigation. A copy of the opinion can be found here.
In X2Y Attenuators the Federal Circuit affirmed an International Trade Commission (ITC) ruling that Intel and several other companies did not infringe X2Y Attenuators’ patents directed to an electrode arrangement for reducing “parasitic capacitance.” Parasitic capacitance is a phenomenon that produces an undesirable build-up of electric charge between electrodes used for conduction. In the embodiments of the X2Y Attenuators’ patents, the electrode configuration included a central electrode that was sandwiched between oppositely charged “differential electrodes” on either side of it. The differential electrodes were not included in the patent claims, presumably because they were not needed to distinguish the prior art considered by the Patent Office.
The ITC held that the claims required the sandwich configuration of two differential electrodes on either side of a central electrode, even though the claims did not recite it. The Federal Circuit affirmed this ruling, based on statements in the patent specification which the Court concluded rose to the level of “specification disavowal.” In particular, one of the patents-in-suit said that the sandwich configuration is “an essential element among all embodiments or connotations of the invention.” The Court noted that it had previously held that labeling an element or feature as “essential” may result in a disavowal of claim scope and that such disavowal applied to X2Y Attenuators’ patent claims.
What is important to note is that this result turned on the drafting of the patents, not on the nature of the invention itself. The Federal Circuit has repeatedly held that it is improper to limit patent claims to features in the specification which are not recited in the claims themselves. Under such case law, patent claims will not be limited to an unclaimed feature in the specification, even if the feature is common to all embodiments and even if a person of ordinary skill in the art would conclude that the feature is “essential” to the operation of the invention. In other words, the X2Y Attenuators decision turns on the specification’s characterization of the embodiments, not on the structure or operation of the embodiments themselves. If the “essential” language had not been included in the patents, the Court almost certainly would have not reached the same holding, even if the embodiments had the exact same structure and function.
So, why would someone ever include this type of “essential” language in a patent? To get the patent in the first place.
During the prosecution of a patent application, the Patent Office will frequently assert that prior art references render patent claims obvious, and therefore, unpatentable. This type of rejection can be overcome if it can be shown that features in the claims are critical or essential because they overcome problems the prior art could not solve. The problem is that when a patent application is being written, the full scope of the prior art is often not known. Even if a patentability search is conducted, the Patent Office may ultimately find more relevant prior art. Therefore, patent attorneys often describe features that they think may be important in securing a patent as “critical” or “essential” so that they have a basis for arguing that those features are not obvious, should it prove necessary to do so. Sometimes, it turns out those features are not necessary to distinguish the prior art, in which case they may not end up in the claims (or at least all of the claims). However, statements characterizing the features as critical or essential can nevertheless prompt a court to treat them as claim limitations.
Thus, there is a tension in drafting a patent application to improve the chances of actually receiving a patent and drafting the application to ensure that the resulting patent claims are not construed narrowly based on the specification embodiments. Obtaining patents that are commercially useful and which will withstand challenges in litigation requires an understanding of this tension and the development of an appropriate application drafting strategy.