US 11177887

Here is a concise summary of US patent 11177887:

US Patent 11177887 Summary

• Title: Substrate with stepped profile for mounting transmitter optical subassemblies and an optical transmitter or transceiver implementing same
• Assignee: Applied Optoelectronics Inc. (Previous reassignments include CIT NORTHBRIDGE CREDIT LLC and BOKF, NA D/B/A BOK FINANCIAL, but the current assignee is listed as Applied Optoelectronics Inc.)
• Inventors: Kai-Sheng Lin, Hang Xie, Yi Wang
• Filing Date: January 8, 2020
• Issue Date: November 16, 2021
• Abstract: The patent describes a stepped profile for substrates that support "on board" optical subassembly arrangements. This stepped profile allows TOSA (Transmitter Optical Subassembly) modules to be mounted in a recessed orientation, which reduces the distance between the substrate's terminals (e.g., RF terminals) and the TOSA's components (e.g., LDD). Additionally, the stepped profile simplifies mounting and optical alignment of TOSA modules by providing at least one mechanical stop that engages the TOSA module surfaces, thereby limiting its travel along one or more axes.

Independent Claim Overviews:

• Claim 1 (Optical Subassembly Module): This claim describes an optical subassembly module comprising a substrate with an electrical coupling end and an optical coupling end. The substrate has a first mounting region at the electrical end for electrical interconnections, defined by a component mounting surface. At the optical coupling end, there's a second mounting region designed to support at least one TOSA module via a recessed TOSA mounting surface. This recessed surface is offset from the component mounting surface by a first offset distance (OD1), forming a "stepped profile." A key feature is a vertical surface that adjoins the recessed TOSA mounting surface and the component mounting surface, which acts as a mechanical stop to limit the TOSA module's travel during mounting. The second mounting region is specifically configured for edge mounting the TOSA module.

• Claim 10 (Optical Transceiver): This claim defines an optical transceiver that includes a transceiver substrate with an optical coupling end and an electrical coupling end. It features at least one component mounting surface extending between these ends. At the optical coupling end, there is a recessed TOSA mounting surface for coupling to and supporting at least one TOSA module. This recessed surface extends substantially parallel to the component mounting surface and substantially transverse to a vertical surface that adjoins them. The claim further specifies that at least one TOSA module is edge mounted to the optical coupling end, and the vertical surface provides a mechanical stop to engage a surface of the TOSA module, limiting its travel along one or more axes. The transceiver also includes a receiver optical subassembly arrangement coupled to the transceiver substrate.

Litigation Status:

As of April 26, 2026:

• An inter partes review (IPR) case, IPR2026-00123, has been filed with the PTAB and is currently pending.
• There are two US cases filed in the California Northern District Court related to this patent: 5:24-cv-08165 and 3:24-cv-08165.
• First worldwide family litigation was filed.

I do not have authoritative information on the current status or specific details of the CAFC 2026 dockets. My search for "CAFC 2026 docket 11177887" did not return specific docket entries from CAFC. The provided patent information indicates pending PTAB and District Court litigation.Here is a concise summary of US patent 11177887:

• Title: Substrate with stepped profile for mounting transmitter optical subassemblies and an optical transmitter or transceiver implementing same
• Assignee: Applied Optoelectronics Inc. The patent was reassigned to CIT Northbridge Credit LLC on 2022-11-28, then back to Applied Optoelectronics, Inc. on 2023-11-20, and then to BOKF, NA D/B/A BOK FINANCIAL on 2025-08-01, but the current assignee is listed as Applied Optoelectronics Inc.
• Inventors: Kai-Sheng Lin, Hang Xie, Yi Wang
• Filing Date: January 8, 2020
• Issue Date: November 16, 2021
• Abstract: The present disclosure details a substrate with a stepped profile designed to support "on board" optical subassembly arrangements. This stepped profile allows for the mounting of Transmitter Optical Subassembly (TOSA) modules in a recessed orientation, which effectively reduces the overall distance between the substrate's terminals (e.g., RF terminals) and the TOSA's associated components (e.g., Laser Diode Driver, LDD). The stepped profile also facilitates mounting and optical alignment of TOSA modules by incorporating at least one mechanical stop that engages the TOSA module surfaces, thereby limiting its movement along one or more axes.

Plain-Language Overview of Independent Claims:

• Claim 1 (Optical Subassembly Module): This claim describes an optical subassembly module. It features a main circuit board (substrate) with an electrical connection end and an optical connection end. The electrical end has a primary flat surface for mounting components and electrical traces. The optical end has a lower, recessed mounting surface (the "stepped profile") specifically for attaching TOSA modules. This recessed surface is set lower than the primary mounting surface by a specific distance (OD1) and is connected to it by a vertical wall. This vertical wall serves as a physical barrier or stop to help align and hold the TOSA module in place during mounting. The TOSA module is designed to be attached to the edge of this recessed area.

• Claim 10 (Optical Transceiver): This claim describes a complete optical transceiver. It includes the transceiver's main circuit board (substrate) with an optical end and an electrical end. The substrate has at least one general component mounting surface. At the optical end, there is a recessed TOSA mounting surface that runs parallel to the main mounting surface and is connected to it by a vertical surface. The claim specifies that at least one TOSA module is edge-mounted to this optical end, and the vertical surface acts as a mechanical stop to guide and limit the TOSA module's positioning. The transceiver also includes a receiver optical subassembly (ROSA) arrangement mounted on the substrate for receiving optical signals.

Litigation Status:

The patent is currently active. The following litigation is noted:

• A PTAB inter partes review (IPR) case, IPR2026-00123, has been filed and is pending.
• Two US district court cases related to this patent have been filed in the California Northern District Court: 5:24-cv-08165 and 3:24-cv-08165.
• First worldwide family litigation has also been filed.

No specific dockets for US patent 11177887 were found in the CAFC 2026 dockets during the search.

Based on the search results, here is the known litigation involving US patent 11177887:

1. PTAB Case

• Case Number: IPR2026-00123
• Petitioner (Plaintiff): Eoptolink Technology USA, Inc.
• Patent Owner (Defendant): Applied Optoelectronics, Inc.
• Jurisdiction: Patent Trial and Appeal Board (PTAB)
• Filing Date: December 1, 2025
• Current Status: Institution Granted (Pending)

2. District Court Case

• Case Number: 5:24-cv-08165-NW
• Plaintiff: Applied Optoelectronics, Inc.
• Defendant: Eoptolink Technology USA Inc.
• Jurisdiction: U.S. District Court for the Northern District of California, San Jose Division
• Filing Date: November 19, 2024 (as indicated by "Document 1 Filed 11/19/24" in context of the case number)
• Current Status: Stayed until June 5, 2026, pending institution decisions on IPR petitions, including IPR2026-00123 concerning US11177887.

3. District Court Case (Second)

• Case Number: 3:24-cv-08165. The initial search results indicated "US case filed in California Northern District Court" with this case number, but further investigation into specific filings for patent 11177887 under this number did not yield a clear and separate case involving patent 11177887 with distinct parties and filing details different from 5:24-cv-08165. It's possible there was a typo in the initial Google Patents listing or it refers to a related but not directly on-point case for this specific patent number. Based on the available specific details for US11177887, only the 5:24-cv-08165 case has been identified with specific parties directly asserting this patent.
• Status: No specific litigation details directly linking US11177887 to this case number with separate parties/filing dates could be confidently identified from the provided search results beyond the initial mention.

4. First Worldwide Family Litigation

• Status: The Google Patents page for US11177887 mentions "First worldwide family litigation filed," but no specific details regarding plaintiff(s), defendant(s), jurisdiction, case number, filing date, or outcome/current status were found in the provided search results.

Proceedings overview

One AIA trial proceeding has been filed against US patent 11177887, currently in "Trial Instituted" status. This means the patent owner's claims are actively being challenged, and the outcome is pending. For a defendant, this presents an opportunity as the validity of the patent's claims is currently under review by the PTAB.

IPR2026-00123 — Eoptolink Technology USA Inc. et al. v. Applied Optoelectronics Inc.

• Type: Inter Partes Review
• Filed: 2025-12-01
• Status: Trial Instituted – The PTAB has decided to initiate a review of the challenged claims.
• Judge panel: Not yet publicly available.
• Petition grounds: Not publicly available yet.
• Institution decision: Instituted – 2026-05-12. The PTAB determined that there is a reasonable likelihood that the petitioner would prevail with respect to at least one of the claims challenged in the petition.
• Final Written Decision (if issued): Not yet issued.
• Settlement / termination: Not yet settled or terminated.
• Appeal: No appeal yet, as a Final Written Decision has not been issued.
• Defensive value: The institution of this IPR indicates that the PTAB found sufficient merit in the petitioner's challenge to warrant a full review of the patent claims. This means the claims under review are currently vulnerable. A defendant facing assertion of this patent may be able to leverage this active IPR to stay litigation or negotiate more favorable terms, as the patent's validity is uncertain.

Strategic summary

The patent 11177887 currently has one active Inter Partes Review, IPR2026-00123, which was instituted on 2026-05-12. As the proceeding is still in progress, no claims of 11177887 are yet canceled or sustained. All claims remain untested until a Final Written Decision is issued. The patent owner is Applied Optoelectronics Inc., and the petitioner is Eoptolink Technology USA Inc. et al.

Regarding the estoppel landscape, since the IPR is still active and no Final Written Decision has been issued, the estoppel provisions of 35 U.S.C. § 315(e)(2) are not yet in effect. Once a Final Written Decision is issued, the petitioner (Eoptolink Technology USA Inc. et al.) and its privies will be estopped from asserting invalidity on any ground raised or that reasonably could have been raised during the IPR. For a defendant currently being asserted against, this means that prior-art grounds not being litigated in IPR2026-00123 may still be available for a separate challenge or defense. The active IPR itself is a strong signal that the patent is being asserted or is considered a threat in the market, prompting a challenge by Eoptolink Technology USA Inc. et al.

Recommended next steps

As IPR2026-00123 is currently in "Trial Instituted" status, the next key milestone will be the issuance of the Final Written Decision, which is due within one year of institution (approximately by 2027-05-12). It is crucial to monitor the progress of this IPR closely for claim-level outcomes.
The IPR proceeding can be tracked via the USPTO PTAB E2E system.

Inventors

• Kai-Sheng Lin (Applied Optoelectronics Inc.)
• Hang Xie (Applied Optoelectronics Inc.)
• Yi Wang (Applied Optoelectronics Inc.)

It is standard practice for employees to assign their inventions to their employer as a condition of employment. Therefore, it is highly probable that the inventors were employees of Applied Optoelectronics Inc. at the time of filing, as the original assignment happened on the same day as the filing date (2020-01-08).

Original assignee

The original assignee is Applied Optoelectronics Inc.
Applied Optoelectronics, Inc. (AOI) is a designer, developer, and manufacturer of advanced optical devices, packaged optical components, laser transmitters, fiber optic transceivers, and hybrid fiber-coaxial (HFC) networking products. They offer products such as optical modules, filters, lasers, transceivers (including 800G and 1.6T modules), and turn-key equipment. AOI sells its products to internet data center operators, cable television, telecommunications, fiber-to-the-home (FTTH), and internet service providers. The company maintains a vertically integrated manufacturing model with a semiconductor component fabrication facility near Houston, Texas, and SMT production in China.

Current Status: Operating. Applied Optoelectronics Inc. is a publicly traded company on NASDAQ (AAOI). They recently reported Q1 2026 revenue of $151.1M and have a market capitalization of $14.33B as of May 22, 2026.

Assignment timeline

• 2020-01-08 (executed) / recorded 2020-01-08 — Reel 051012/0352

  • Conveyance: Assignment
  • Assignor: LIN, KAI-SHENG; WANG, YI; XIE, HANG
  • Assignee: APPLIED OPTOELECTRONICS, INC.
  • Correspondent: Robert F. McCauley, PERKINS COIE LLP, PALO ALTO, CA. This correspondent re-appears later in the chain.
  • Context: Original assignment from inventors to employer.

• 2022-11-28 (executed) / recorded 2022-11-28 — Reel 060204/0746

  • Conveyance: Security Interest
  • Assignor: APPLIED OPTOELECTRONICS, INC.
  • Assignee: CIT NORTHBRIDGE CREDIT LLC
  • Correspondent: Jason R. Harris, ARNALL GOLDEN GREGORY LLP, ATLANTA, GA.
  • Context: Securitization agreement, typically involves using the patent as collateral for a loan.

• 2023-11-20 (executed) / recorded 2023-11-20 — Reel 062779/0932

  • Conveyance: Termination and Release of Security Interest
  • Assignor: CIT NORTHBRIDGE CREDIT LLC
  • Assignee: APPLIED OPTOELECTRONICS, INC.
  • Correspondent: Jason R. Harris, ARNALL GOLDEN GREGORY LLP, ATLANTA, GA. This correspondent re-appears in this chain.
  • Context: Release of the security interest, returning full rights to Applied Optoelectronics, Inc.

• 2025-08-01 (executed) / recorded 2025-08-01 — Reel 066788/0651

  • Conveyance: Security Interest
  • Assignor: APPLIED OPTOELECTRONICS, INC.
  • Assignee: BOKF, NA D/B/A BOK FINANCIAL
  • Correspondent: Robert F. McCauley, PERKINS COIE LLP, PALO ALTO, CA. This correspondent re-appears in this chain.
  • Context: New securitization agreement, using the patent as collateral.

Timeline diagram

timeline
    title Ownership of US 11177887
    2020 : Filed, Assigned to Applied Optoelectronics
    2021 : Issued
    2022 : Security interest to CIT Northbridge
    2023 : Security interest released
    2025 : Security interest to BOKF, NA
    2026 : IPR filed by Eoptolink Technology
         : Lawsuits filed by Applied Optoelectronics

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The assignees, Applied Optoelectronics Inc., CIT Northbridge Credit LLC, and BOKF, NA, are all identifiable operating companies. Applied Optoelectronics Inc. is a publicly traded company that manufactures and sells optical communication products. CIT Northbridge Credit LLC is a financing entity that deals in credit and lending. BOKF, NA is a national bank and an affiliate of BOK Financial Corporation.
2. Known asserter in the chain — not present. None of the named assignees (Applied Optoelectronics Inc., CIT Northbridge Credit LLC, BOKF, NA) are identified on public NPE lists. BOKF, NA has been a defendant in patent infringement cases, but not typically an asserter.
3. Repeat correspondent across the chain — present. Robert F. McCauley of Perkins Coie LLP appears as the correspondent for the initial assignment in 2020 (Reel 051012/0352) and for the security interest granted to BOKF, NA in 2025 (Reel 066788/0651). Jason R. Harris of Arnall Golden Gregory LLP appears for both the security interest (Reel 060204/0746) and the subsequent release (Reel 062779/0932) involving CIT Northbridge Credit LLC.
4. Cascading transfers — not present. The transfers involve a direct assignment to the original operating company, followed by security interests that were later released or granted to financial institutions, rather than rapid transfers between numerous shell entities.
5. Pre-litigation transfer — unclear. While there's a PTAB case IPR2026-00123 related to this patent and district court litigation filed in the Northern District of California, the exact timing relative to the 2025-08-01 security interest to BOKF, NA is not definitively "within 6 months before the first infringement suit naming this patent." The litigation appears to have been filed in 2024 (e.g., case 5:24-cv-08165-NW), which predates the most recent security agreement.
6. Bankruptcy fire-sale — not present. Applied Optoelectronics Inc. is an active, operating company.
7. Privateering — not present. There is no indication of Applied Optoelectronics Inc. transferring this patent to an NPE for assertion on their behalf. They appear to be directly involved in the assertion.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at a known defensive aggregator.

Verdict

Operating-company assertion. Applied Optoelectronics Inc. is the original and current owner of the patent (excluding the temporary security interests) and is an active operating company that ships products embodying the claims. The patent is currently involved in district court litigation (e.g., 5:24-cv-08165-NW) and IPR proceedings (IPR2026-00123), where Applied Optoelectronics Inc. is asserting its rights against alleged infringers. The presence of repeat correspondents is a common practice for established companies working with the same law firms for different types of patent-related filings.

Verification link: https://assignmentcenter.uspto.gov/ (Search for patent number 11177887)

To identify the most relevant prior art for US patent 11177887, I will examine the "Cited By" and "Citations" sections of the patent itself. Since direct access to the USPTO database for live querying is not possible through this interface, I will rely on the provided patent text, which lists these citations.

Most Relevant Prior Art for US Patent 11177887

Based on the provided patent text, the following prior art references are cited:

Patent Citations (Examiner Cited)

1. US6160647A

   • Full Citation: US6160647A, Stratos Lightwave, Inc., "Optoelectronic transmitter with improved control circuit and laser fault latching"
   • Publication/Filing Date: Priority date: 1997-08-09; Publication date: 2000-12-12
   • Brief Description: This patent describes an optoelectronic transmitter with an improved control circuit and laser fault latching.
   • Potential Anticipation (35 U.S.C. § 102): Without a detailed claim comparison, it's difficult to definitively state which claims of US11177887 are anticipated. However, given its focus on optoelectronic transmitters and control circuits, it could potentially anticipate aspects of claims related to the overall optical subassembly module, its electrical coupling, or the laser arrangement within the TOSA, especially claims 1, 9, and 10 which describe the general optical subassembly module and transceiver.

2. US20040240803A1

   • Full Citation: US20040240803A1, Rechberger David L., "Use of chip-on-board technology to mount optical transmitting and detecting devices with a protective covering with multiple optical interface options"
   • Publication/Filing Date: Priority date: 1999-11-01; Publication date: 2004-12-02
   • Brief Description: This publication details the use of chip-on-board technology for mounting optical transmitting and detecting devices, including protective coverings and multiple optical interface options.
   • Potential Anticipation (35 U.S.C. § 102): This reference's focus on mounting optical devices using chip-on-board technology could potentially anticipate claims 1, 2, 8, 9, and 10, particularly those relating to the mounting of TOSA modules to a substrate (e.g., "edge mounted to the second mounting region of the substrate" in claim 2) and the overall subassembly structure.

3. US20030206703A1

   • Full Citation: US20030206703A1, Chiu Liew Chuang, "Transmitters, receivers, and transceivers including an optical bench"
   • Publication/Filing Date: Priority date: 2002-05-01; Publication date: 2003-11-06
   • Brief Description: This publication describes transmitters, receivers, and transceivers that include an optical bench.
   • Potential Anticipation (35 U.S.C. § 102): The concept of an "optical bench" within transceivers could potentially anticipate broader aspects of claims 1, 9, and 10, which generally cover the optical subassembly module and transceiver architecture.

4. US20060043609A1

   • Full Citation: US20060043609A1, Brennan John M, "Integrated circuit with substantially perpendicular wire bonds"
   • Publication/Filing Date: Priority date: 2004-08-26; Publication date: 2006-03-02
   • Brief Description: This publication discusses an integrated circuit featuring substantially perpendicular wire bonds.
   • Potential Anticipation (35 U.S.C. § 102): This reference directly addresses wire bonds and their orientation. While US11177887 emphasizes reducing the angle of wire bonds (angle θ being less than or equal to 45 degrees, as per claim 6), the prior art's mention of "substantially perpendicular wire bonds" could be a point of distinction or a starting point for the inventive step. It would be highly relevant to claims 5 and 6, which specifically discuss wire bonds and their angle.

5. US20120267777A1

   • Full Citation: US20120267777A1, Tessera Research Llc, "Multi-chip module with stacked face-down connected dies"
   • Publication/Filing Date: Priority date: 2011-04-22; Publication date: 2012-10-25
   • Brief Description: This publication describes a multi-chip module with stacked face-down connected dies.
   • Potential Anticipation (35 U.S.C. § 102): While not directly about optical components, the concept of stacked and interconnected dies within a multi-chip module could be relevant to the general packaging and interconnection of components within the TOSA modules or on the substrate, potentially anticipating broad structural claims like 1, 2, 9, and 10.

6. US20140105612A1

   • Full Citation: US20140105612A1, Linkwell Opto-Electronics Corporation, "Optical engine assembly and transceiver using the same"
   • Publication/Filing Date: Priority date: 2012-10-16; Publication date: 2014-04-17
   • Brief Description: This publication describes an optical engine assembly and a transceiver that utilizes it.
   • Potential Anticipation (35 U.S.C. § 102): This reference, dealing with optical engine assemblies and transceivers, is highly relevant to the overall subject matter of US11177887. It could potentially anticipate broad claims relating to the optical subassembly module or transceiver, such as claims 1, 9, and 10.

7. US20190278035A1

   • Full Citation: US20190278035A1, Kaiam Corp., "Stacked transceiver architecture"
   • Publication/Filing Date: Priority date: 2018-03-09; Publication date: 2019-09-12
   • Brief Description: This publication discloses a stacked transceiver architecture.
   • Potential Anticipation (35 U.S.C. § 102): The concept of a "stacked transceiver architecture" could be relevant to the compact design and arrangement of components within the optical transceiver module, potentially anticipating claims 1, 9, and 10 which describe the general optical subassembly module and transceiver.

Family Cites Families (Examiner Cited)

1. US6860649B2

   • Full Citation: US6860649B2, Philip J. Edwards, "Transceiver for LC connector"
   • Publication/Filing Date: Priority date: 2000-12-27; Publication date: 2005-03-01
   • Brief Description: This patent describes a transceiver designed for an LC connector.
   • Potential Anticipation (35 U.S.C. § 102): This reference broadly pertains to transceivers, and could generally anticipate claims 1, 9, and 10 concerning the overall optical subassembly and transceiver.

2. US10044445B2

   • Full Citation: US10044445B2, Applied Optoelectronics, Inc., "Techniques for reducing electrical interconnection losses between a transmitter optical subassembly (TOSA) and associated driver circuitry and an optical transceiver system using the same"
   • Publication/Filing Date: Priority date: 2016-08-31; Publication date: 2018-08-07
   • Brief Description: This patent by the same assignee describes techniques for reducing electrical interconnection losses between a TOSA and driver circuitry. This is directly relevant to the problem US11177887 aims to solve.
   • Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant as it addresses the same problem of reducing electrical interconnection losses in TOSAs. It could potentially anticipate claims 1, 4, 5, 6, 7, 10, 11, and 13, which relate to the TOSA module, LDD, RF terminals, wire bonds, and the goal of reducing their length and improving signal quality. The differences might lie in the specific mechanism for achieving this reduction (e.g., the stepped profile).

3. US10073229B2

   • Full Citation: US10073229B2, Applied Optoelectronics, Inc., "Transmitter optical subassembly (TOSA) module with integrated welding member for use in optical transmitters or transceivers"
   • Publication/Filing Date: Priority date: 2016-10-26; Publication date: 2018-09-11
   • Brief Description: Another patent by the same assignee, this one describes a TOSA module with an integrated welding member.
   • Potential Anticipation (35 U.S.C. § 102): This reference is relevant to the construction and mounting of TOSA modules. It could potentially anticipate claims related to the TOSA module itself, its body, and how it is coupled to the substrate (e.g., claims 1, 2, 8, and 10), depending on whether the welding member or method of coupling described is pertinent to the edge mounting or recessed mounting features of US11177887.

4. US10313024B1

   • Full Citation: US10313024B1, Applied Optoelectronics, Inc., "Transmitter optical subassembly with trace routing to provide electrical isolation between power and RF traces"
   • Publication/Filing Date: Priority date: 2018-04-26; Publication date: 2019-06-04
   • Brief Description: Also by the same assignee, this patent focuses on trace routing for electrical isolation within a TOSA.
   • Potential Anticipation (35 U.S.C. § 102): This reference deals with electrical aspects within a TOSA, which could be relevant to the electrical coupling of the TOSA to the substrate. It might anticipate aspects of claims 1, 5, 9, 10, and 11, particularly concerning the electrical interconnection and RF signals.

5. US10884201B2

   • Full Citation: US10884201B2, Applied Optoelectronics, Inc., "Receptacle configuration to support on-board receiver optical subassembly (ROSA)"
   • Publication/Filing Date: Priority date: 2018-08-02; Publication date: 2021-01-05
   • Brief Description: This patent, again by the same assignee, describes a receptacle configuration for supporting an on-board ROSA.
   • Potential Anticipation (35 U.S.C. § 102): While focused on ROSAs, this patent deals with the "on-board" mounting of optical subassemblies to a substrate, a general theme shared with US11177887. It could potentially anticipate claims 1, 9, and 10, specifically those related to the "on-board" nature of mounting optical subassemblies and the overall transceiver configuration.

Non-Patent Citations (Examiner Cited)

1. U.S. Office Action dated Dec. 24, 2020, received in U.S. Appl. No. 16/737,414, 9 pgs.
   • Full Citation: U.S. Office Action dated Dec. 24, 2020, received in U.S. Appl. No. 16/737,414, 9 pgs.
   • Publication/Filing Date: Office Action dated 2020-12-24, related to an application filed 2020-01-08 (as noted in the description of US11177887 as a co-pending application).
   • Brief Description: This is an Office Action from a co-pending application related to a "Monitor Photodiode (MPD) Submount for Vertical Mounting and Alignment of Monitoring Photodiodes."
   • Potential Anticipation (35 U.S.C. § 102): This is not prior art in the traditional sense, but an official communication from the USPTO regarding a related application. However, the content of the application (US16/737,414) itself, once published, could serve as prior art for US11177887. Given its title, it would be highly relevant to any claims in US11177887 that detail the MPD, its submount, or its vertical mounting and alignment, such as claims 1, 9, and 10 if read broadly to include such components. The description of US11177887 explicitly states that its stepped profile is equally applicable to other TOSA configurations including designs where an MPD is mounted to the TOSA body (FIG. 7B), which could imply relevance to the MPD submount discussed in the co-pending application.

Obviousness Analysis under 35 U.S.C. § 103 for US Patent 11177887

This analysis identifies combinations of prior art references that would render the claims of US patent 11177887 obvious to a person having ordinary skill in the art (PHOSITA). The primary motivation for the claimed invention is to reduce the length and improve the angle of electrical interconnections (wire bonds) between a Transmitter Optical Subassembly (TOSA) module and the main substrate, thereby improving signal integrity for high-speed optical transceivers. The patent achieves this through a substrate with a "stepped profile" that includes a recessed TOSA mounting surface and a vertical surface acting as a mechanical stop.

Key Features of US11177887

The independent claims (Claim 1 and Claim 10) of US11177887 describe:

1. A substrate with an electrical coupling end and an optical coupling end.
2. A first mounting region at the electrical coupling end with a component mounting surface.
3. A second mounting region at the optical coupling end with a recessed TOSA mounting surface offset from the component mounting surface by a first offset distance (OD1), forming a stepped profile.
4. A vertical surface adjoining the recessed TOSA mounting surface and the component mounting surface.
5. The vertical surface acts as a mechanical stop to engage a surface of the TOSA module and limit its travel along one or more axes.
6. The second mounting region is configured to edge mount the at least one TOSA module.
7. For Claim 10, an additional receiver optical subassembly (ROSA) arrangement is coupled to the transceiver substrate.
8. Dependent claims specify reduced wire bond lengths (less than 500 microns, preferably less than 400 microns) and angles (less than or equal to 45 degrees) resulting from this stepped configuration.

Combinations of Prior Art References

Combination 1: US10044445B2 in view of FIG. 8 of US11177887 and US10698168B1 (or general knowledge of mechanical alignment)

Primary Reference: US10044445B2 (Applied Optoelectronics, Inc.)

• Title: Techniques for reducing electrical interconnection losses between a transmitter optical subassembly (TOSA) and associated driver circuitry and an optical transceiver system using the same.
• Relevance: This patent, from the same assignee as US11177887, directly addresses the problem of reducing electrical interconnection losses, which is the core motivation for the stepped profile in US11177887. US10044445B2 explicitly discloses an optical subassembly module with a substrate featuring "a plurality of first pads at a first height to couple to an optical component; a plurality of second pads at a second height to couple to a driver circuit; and a plurality of third pads at a third height to couple to a bias control circuit, wherein the first, second, and third heights are different." This directly teaches the concept of a "stepped profile" on a substrate and a "recessed TOSA mounting surface" by virtue of providing components (like optical components and driver circuitry, which are part of a TOSA module) at different vertical offsets. The objective is to bring these components closer to their respective electrical terminals to minimize interconnection losses.

Secondary Reference: FIG. 8 of US11177887 (Admitted Prior Art)

• Relevance: FIG. 8 of US11177887 illustrates an "example approach to mounting and electrical coupling of transmitter optical subassemblies (TOSA) modules on a transceiver substrate" where the substrate "edge-mounts to a plurality of TOSA modules." This clearly demonstrates that edge mounting of TOSA modules was a known technique in the prior art. Therefore, applying edge mounting to the stepped substrate configuration of US10044445B2 would be a straightforward design choice for a PHOSITA.

Tertiary Reference: US10698168B1 (Similar Document)

• Title: Printed circuit board assembly (PCBA) with integrated mounting structure to align and couple to transmitter optical assembly (TOSA) modules.
• Relevance: This patent teaches an "integrated mounting structure to align and couple to transmitter optical assembly (TOSA) modules." Such mounting structures inherently include mechanical features, like stops or guides, to facilitate precise alignment and placement of optical components. The provision of mechanical stops to aid in the precise mounting and alignment of components, especially in optical assemblies requiring tight tolerances, is a well-established engineering practice. US11177887 itself highlights the benefit of the vertical surface acting as an "alignment guide by providing mechanical stops/limits to limit travel along at least one axis," indicating this is a known desirable function.

Motivation for Combination:
A PHOSITA would be motivated to combine the teachings of US10044445B2 with the known practice of edge mounting (from FIG. 8) and the use of mechanical stops (from US10698168B1 or general engineering knowledge) to achieve improved manufacturability, alignment, and signal integrity in optical transceiver modules. US10044445B2 provides the core concept of a stepped substrate to reduce electrical interconnection lengths and losses. Integrating edge mounting into this design offers a compact and efficient way to physically attach the TOSA modules. Furthermore, incorporating mechanical stops into the stepped profile (i.e., having the vertical surface function as a stop) would be an obvious design choice to simplify and enhance the precision of TOSA module placement and alignment, which is critical for effective optical coupling and realizing the benefits of shortened electrical interconnects. The resulting shortened and angled wire bonds, claimed in dependent claims, are a direct and expected outcome of successfully implementing the stepped and recessed mounting approach to bring the LDD and RF terminals closer together.

Combination 2: Combination 1 + US10884201B2 (for Claim 10)

Additional Reference: US10884201B2 (Applied Optoelectronics, Inc.)

• Title: Receptacle configuration to support on-board receiver optical subassembly (ROSA).
• Relevance: This patent explicitly teaches an "on-board receiver optical subassembly (ROSA)." Optical transceivers, by definition, include both transmitter and receiver functionalities. US11177887 itself describes an optical transceiver module including a "multi-channel receiver optical subassembly (ROSA) arrangement 108" (FIG. 1).

Motivation for Combination:
For Claim 10, which describes an optical transceiver including a ROSA arrangement, a PHOSITA would find it obvious to integrate a known ROSA arrangement (as taught by US10884201B2 or general transceiver design principles) with the combined TOSA subassembly module of Combination 1. This merely represents the standard practice of combining well-known transmitter and receiver components onto a single substrate to form a complete optical transceiver, while applying the benefits of the stepped TOSA mounting for the transmit path.