Vitronics Corporation v. Conceptronic, Inc.

Citation: Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 39 U.S.P.Q.2D (BNA) 1573 (Fed. Cir. 1996).

Factual Background
Vitronics and Conceptronic are both in the business of manufacturing ovens used to solder electronic devices to circuit boards. Vitronics holds a patent on a particular method of soldering boards (the '502 patent) in which boards attached to devices with solder paste are sent through a multizone oven. In the last zone of the oven the temperature is high enough to melt the paste and form a connection while the temperature of the device is kept below the solder reflow temperature. This difference in temperature is what causes the solder to flow up the device connections for a more solid connection.

Vitronics brought this action against Conceptronic for infringement of the '502 patent and the U.S. Patent No. 4,833,301 (the '301 patent) (a jury found there to be no infringement of the '301 patent and Vitronics does not appeal that finding in this case). Vitronics asked the court to determine the meaning of "solder reflow temperature". Vitronics contended that "solder reflow temperature" as used in the '502 patent means "the temperature reached by the solder during the period it is reflowing during the final stages of the soldering process, sometimes referred to as the 'peak solder reflow temperature.' It does not mean the 'liquidus temperature' the temperature at which the solder first begins to melt. Thus if the temperature of the device stays below that of the solder, the '502 patent method is infringed." Conceptronic argues that solder reflow temperature means 183 degrees C which is equivalent to the liquidus temperature of a known type of solder (Sn/Pb).

One specification contained in the '502 patent claim described a preferred embodiment that stated that "the solder is raised to 210 degrees C, the peak reflow temperature, and the temperature of the devices is raised to 195 degrees C, 5 degrees above the 190 degrees C liquidus temperature"

District Court:
Conceptronic entered extrinsic evidence into the record including expert testimony and papers written by Vitronics employees. The District Court ruled that solder reflow temperature meant 183 degrees C without stating what evidence, extrinsic or intrinsic, was relied upon.

Appellate Court
The Appellate Court reversed the judgment of non-infringement as a matter of law and remanded for a determination based on intrinsic evidence and of Conceptronic's alternative argument that Vitronic "failed to test the temperature of all the various devices in the boards" and that "certain of the Vitronic tests demonstrated that many of the devices reached temperatures above the peak flow temperatures."

Two determinations must be made in a patent infringement case; an analysis of the proper construction of the claim and a finding of infringement of the claim as properly construed. Only the issue of claim construction is on appeal in this case.

Under the Markman] decision the court should consider intrinsic evidence such as the [[patent, specifications, and prosecution history first when determining the proper construction of a claim. When reading a claim words are given their "ordinary and customary" meaning unless a patentee makes it clear, either in the claim or the specifications, that a term has a special meaning in which case the patentee is free to be their own lexicographer.

The Appellate Court determined that the meaning of "solder reflow temperature" in the '502 patent is clear from the reading of the claim and that extrinsic evidence was not needed since there was no longer any ambiguity. Holding that "peak reflow temperature" and "liquidus temperature" are clearly defined in the specifications, the court found that if "solder reflow temperature" meant liquidus temperature then the preferred embodiment in the specification would not be covered by the patent claim.

Conceptronic argued that regardless of the definition of "solder reflow temperature" Vitronics' evidence does not prove infringement due to errors in the testing and reporting of results.

This court reversed and remanded for a finding of proper claim construction based on intrinsic evidence and a determination of Conceptronic's allegations of improper testing.