Advanced Semiconductor Engineering Inc v. Bell Semiconductor LLC

1. Case Identification

• Case #: IPR2021-00180
• Patent #: 6,624,007
• Filed: November 10, 2020
• Petitioner(s): Advanced Semiconductor Engineering, Inc.
• Patent Owner(s): Bell Semiconductor, LLC
• Challenged Claims: 1-8

2. Patent Overview

• Title: Method for Manufacturing Semiconductor Devices
• Brief Description: The ’007 patent discloses methods for manufacturing semiconductor devices and the leadframes used therein. The technology covers two distinct processes: a two-step cutting method using cutters of different thicknesses to singulate devices from a leadframe, and a multi-step mechanical method (punching, stamping, and second punching) to form the leadframe itself from an electroconductive plate.

3. Grounds for Unpatentability

Ground 1: Claims 1 and 3 are anticipated by Matsuo under 35 U.S.C. §102.

• Prior Art Relied Upon: Matsuo (JP Patent Publication 2001-77263).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Matsuo’s fourth embodiment, which addresses the same problem of metal burrs during lead cutting, discloses every limitation of claims 1 and 3. Matsuo teaches a method of making a semiconductor device by mounting a chip on a leadframe, encapsulating it with a sealing resin to form an intermediate product, and then cutting the product. Crucially, Matsuo describes a multi-stage cutting process using a first cutter (rotating blade 11) with a first thickness for making a full cut and a second cutter (rotating blade 17) with a greater thickness for making a partial cut, with both cuts corresponding in position. This allegedly anticipates all elements of claim 1.
  • Key Aspects: For claim 3, which requires the full cut to be made after the partial cut, Petitioner asserted that Matsuo explicitly discloses this sequence. Matsuo’s process first uses the wider blade (17) to form a partial "first cut groove" and subsequently uses the narrower blade (11) to perform a full cut at the same location.

Ground 2: Claim 8 is anticipated or rendered obvious by Higuchi under 35 U.S.C. §102/§103.

• Prior Art Relied Upon: Higuchi (JP Patent Publication H9-102573).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Higuchi’s five-step mechanical process for manufacturing a leadframe anticipates or makes obvious all limitations of claim 8. Higuchi discloses a first punching step on an electroconductive plate of uniform thickness to form openings ("supplementary through holes"). It then discloses a stamping ("coining" or "crushing") step where portions of the leadframe are compressed, reducing their thickness and causing them to spread into the previously formed openings. Finally, Higuchi teaches a second punching ("pressing process") step to remove unnecessary parts from the stamped portion, such as connecting pieces.
  • Key Aspects: Petitioner presented this ground as both anticipation and obviousness. The obviousness argument was framed as an alternative, asserting that if the Patent Owner were to argue Higuchi’s terms like "coining" and "pressing" do not meet the claim terms "stamping" and "punching," a POSITA would have found it obvious to substitute these well-known and interchangeable metalworking techniques to achieve the same predictable results.

Ground 3: Claim 4 is obvious over Matsuo in view of Shibata under 35 U.S.C. §103.

• Prior Art Relied Upon: Matsuo (JP Patent Publication 2001-77263) and Shibata (Patent 5,371,943).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground built upon the teachings of Matsuo for the base method of claim 1. Dependent claim 4 adds the step of "preparing the leadframe by processing an electroconductive material having a uniform thickness." Petitioner argued that while Matsuo describes preparing a leadframe, it omits the specific details of its formation. Shibata was cited to supply this missing element, as it discloses a conventional method of making a leadframe by punching or etching a "metal plate" having a "uniform thickness."
  • Motivation to Combine: A POSITA would combine these references because Matsuo’s disclosure of the leadframe preparation step is generic. It would have been a natural and logical step for a POSITA to look to known, conventional leadframe manufacturing processes, such as the one described in Shibata, to implement Matsuo’s method.
  • Expectation of Success: Petitioner argued there was a high expectation of success, as the combination merely involved applying a standard, well-known initial step (leadframe formation from a uniform plate per Shibata) to a subsequent, known manufacturing process (packaging and cutting per Matsuo), which would predictably result in the device described by Matsuo.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that reversing the cutting order in Matsuo (claim 2) would have been obvious based on Matsuo alone or in combination with Fukasawa, and that claims 4-7 are obvious over the combination of Matsuo and Higuchi.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise discretionary denial under 35 U.S.C. §325(d) because the prior art references presented in the petition were not applied during the original prosecution of the ’007 patent.
• Petitioner also argued against discretionary denial under Fintiv factors. It contended that because it is not a party to any of the four pending parallel litigations involving the ’007 patent, the Fintiv analysis weighs against denial. Key factors cited included the early stage of the co-pending cases, trial dates more than 15 months away, and the strong merits of the petition, particularly the anticipation grounds against both independent claims.

5. Relief Requested

• Petitioner requests the institution of an inter partes review and cancellation of claims 1-8 of Patent 6,624,007 as unpatentable.