PTAB

IPR2015-00244

View Inc v. Sage ElectrochRomics Inc

Key Events

Petition

petition Intelligence

Title: Sputtering Target Element
Brief Description: The ’336 patent discloses a sputtering target element for depositing thin films of lithium. The invention is directed to a structure comprising a top layer of metallic lithium that is metallurgically bonded to an underlying metallic supporting layer to improve heat transfer and prevent melting during ion bombardment.

Prior Art Relied Upon: Kawade et al., Thick Lithium Metal Target for Fast Neutron Production, 10 J. Nuclear Sci. and Tech 8 (August 1973) (“Kawade”).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Kawade, a reference concerning targets for neutron production, disclosed every limitation of claim 1. Kawade described a target made by "melt-coating" a layer of pure (100%) lithium metal onto a copper backing plate. Petitioner contended this melt-coating process, which involves fusing the metals, inherently creates the "metallurgical bond" recited in the claim. The pure lithium layer and copper backing plate were alleged to meet the "metallic lithium" and "metallic supporting layer" limitations, respectively.
- Key Aspects: Petitioner asserted that even though Kawade's target was for neutron production, the preamble term "sputtering target element" was met because the structure is capable of being used for sputtering, and sputtering would necessarily occur during the ion bombardment inherent in neutron production.

Prior Art Relied Upon: Kawade, Stein et al., Angular Distributions of Argon Sputtered Lithium, 36 J. Applied Phys. (Apr. 1965) (“Stein”), and Dzioba et al., On the Kinetic Energies of Sputtered Excited Particles (1980) (“Dzioba”).
Core Argument for this Ground:
- Prior Art Mapping: This ground was presented as an alternative in case the preamble "sputtering target element" was deemed limiting. Petitioner asserted that Kawade taught the complete physical structure of the claimed target: a lithium layer metallurgically bonded to a copper support. The secondary references, Stein and Dzioba, explicitly disclosed the use of pure metallic lithium targets for the specific purpose of sputtering.
- Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Kawade with Stein or Dzioba because neutron production and sputtering are analogous arts, both involving ion bombardment that generates significant heat. A POSITA seeking to create a durable sputtering target would have looked to related fields like neutron production for solutions to the common problem of heat dissipation and found Kawade's robust, melt-coated target structure.
- Expectation of Success: A POSITA would have had a high expectation of success because the combination required no modification to Kawade's structure, but merely repurposed a known target design for a closely related and predictable application.

Prior Art Relied Upon: Mueller (Patent 5,230,459), Stein, and Dzioba.
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued Mueller disclosed a generic sputtering target structure meeting most claim limitations. Mueller taught bonding a target material to a "high thermal conductivity metal" backing plate (e.g., copper) using methods like diffusion bonding, which induce "metallurgical joining." While Mueller stated its method was "applicable to a host of... target/backing plate compositions" and claimed any "metal or alloy to be sputtered," it did not explicitly name lithium. Stein and Dzioba supplied this missing element by teaching the known desirability of using pure metallic lithium for sputtering.
- Motivation to Combine: A POSITA would combine the references as a matter of simple design choice. It would have been obvious to use a known and desirable sputtering material (metallic lithium from Stein or Dzioba) with the advantageous general-purpose target structure taught by Mueller. The motivation was to achieve the known benefits of Mueller's structure (improved thermal management) with a known high-performance sputtering material.
- Expectation of Success: Success would be predictable, as it involved the simple substitution of one known element (a sputtering material) into another known element (a target assembly) to solve a well-understood problem.

"Metallurgically Bonded": Petitioner argued this term should be construed according to its explicit definition in the ’336 patent: "an interface between metallic layers at which the metallic layers are substantially bonded to one another and in which the interface consists essentially of metals and intermetallic compounds." This construction was critical, as it distinguished the claimed bond from mere mechanical compression, a distinction the applicant made during prosecution to overcome prior art.
Preamble ("a sputtering target element"): Petitioner contended the preamble was non-limiting because it merely stated an intended use for a structurally complete apparatus defined in the body of the claim. However, Petitioner provided obviousness grounds (Grounds 2 and 3 above) as an alternative in the event the Board construed the preamble as a limitation requiring the target to be used for sputtering.

Petitioner requested institution of an inter partes review and cancellation of claim 1 of Patent 5,830,336 as unpatentable.