Pacific Research Group Pte Ltd v. Analog Devices Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Case: Pacific Research Group Pte. Ltd. v. Analog Devices, Inc.
  • Plaintiff: Pacific Research Group Pte. Ltd. (Singapore)
  • Defendant: Analog Devices, Inc. (Commonwealth of Massachusetts)
  • Plaintiff's Counsel: Skiermont Derby LLP
• Case Identification: 7:26-cv-00186, W.D. Tex., 05/08/2026
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has established and regular places of business in the district, has transacted business there, and has committed acts of infringement within the district, including having physical facilities and employees in Austin, Texas.
• Core Dispute: Plaintiff alleges that Defendant's micro-electro-mechanical systems (MEMS) sensor products infringe four U.S. patents related to the integration, packaging, and fabrication of MEMS and semiconductor circuits.
• Technical Context: The technology concerns advanced methods for integrating MEMS sensors and CMOS logic onto a single, compact chip, a critical process for manufacturing the small, power-efficient sensors used in modern electronics.
• Key Procedural History: The complaint alleges that Plaintiff provided Defendant with pre-suit notice of infringement of the asserted patents via a letter dated April 7, 2026, to which Defendant allegedly did not respond.

Case Timeline

Date	Event
2009-11-13	'252 Patent Priority Date
2009-11-30	'666 Patent Priority Date
2010-07-23	'560 Patent Priority Date
2010-08-19	'312 Patent Priority Date
2013-03-12	'252 Patent Issued
2013-03-26	'666 Patent Issued
2015-03-17	'560 Patent Issued
2016-06-28	'312 Patent Issued
2026-04-07	Plaintiff allegedly sent pre-suit notice letter to Defendant
2026-05-08	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,402,666 - Magneto Meter Using Lorentz Force For Integrated Systems (issued Mar. 26, 2013)

The Invention Explained

• Problem Addressed: The patent describes the ongoing challenge of integrating MEMS devices with complex CMOS integrated circuits (ICs) to create smaller, higher-performing, and lower-cost microsystems '666 Patent, col. 1:19 - col. 2:17
• The Patented Solution: The patent proposes an integrated electronic compass and circuit system where the sensor component (the "electronic compass device") and its control logic (the "CMOS integrated circuits") are fabricated on a single common semiconductor substrate '666 Patent, abstract '666 Patent, col. 2:35-42 This integration is intended to reduce parasitic resistances and capacitances, improve accuracy, and enable mass production of smaller units '666 Patent, col. 5:9-25
• Technical Importance: This monolithic integration of a sensor and its logic on a single chip represented a step toward creating compact, low-power, and high-yield sensor systems for mass-market consumer electronics '666 Patent, col. 2:44-54

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶36
• The essential elements of Claim 1 are:
  • An integrated electronic compass and circuit system comprising:
  • a semiconductor substrate;
  • one or more CMOS integrated circuits formed on one or more portions of the semiconductor substrate; and
  • an electronic compass device operably coupled to the one or more CMOS integrated circuits.
• The complaint alleges infringement of "one or more claims," reserving the right to assert others Compl. ¶34

U.S. Patent No. 8,981,560 - Method And Structure of Sensors and MEMs Devices Using Vertical Mounting with Interconnections (issued Mar. 17, 2015)

The Invention Explained

• Problem Addressed: The patent addresses the difficulty of integrating sensors that measure different axes of motion (e.g., an x-y axis sensor and a z-axis sensor) onto a single package, particularly when one component must be mounted vertically '560 Patent, col. 3:22-29
• The Patented Solution: The invention provides a structure and method where a sensor die is "singulated" (cut) in a way that exposes contact regions on its side surface, allowing it to be mounted vertically onto a substrate '560 Patent, abstract '560 Patent, col. 5:32-48 Electrical connections are then made using layers of conductive material that bridge the vertically mounted die and the substrate, replacing traditional wire bonds '560 Patent, Fig. 3
• Technical Importance: This vertical mounting technique enables the creation of more compact, multi-axis sensor packages by allowing components with different orientations to be integrated onto a single substrate '560 Patent, col. 3:22-29

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶54
• The essential elements of Claim 1 are:
  • An integrated sensor device or electronic device, the device comprising:
  • a substrate member having a first surface region, the substrate member having at least one contact region;
  • at least one singulated integrated sensor or electronic device each coupled to a die member, each die member having a singulated surface region and at least one contact region, the singulated surface region(s) being coupled to the first surface region;
  • at least one first conductive material formed overlying at least the contact region(s) of the singulated integrated sensor or electronic device; and
  • at least one second conductive material formed overlying at least a portion of the first conductive material(s).
• The complaint alleges infringement of "one or more claims," reserving the right to assert others Compl. ¶52

Multi-Patent Capsule: U.S. Patent No. 9,376,312

• Patent Identification: U.S. Patent No. 9,376,312, "Method For Fabricating a Transducer Apparatus," issued June 28, 2016 Compl. ¶22
• Technology Synopsis: The patent describes a method of fabricating a MEMS transducer, such as an accelerometer, designed to be tolerant of external deformations '312 Patent, col. 2:15-19 The method involves forming a movable structure with a central anchor, springs, and capacitor elements arranged within a "substantially circular portion" on the substrate, which is intended to minimize strain-induced errors '312 Patent, abstract '312 Patent, col. 2:35-41
• Asserted Claims: The complaint asserts independent claim 1 Compl. ¶72
• Accused Features: The complaint alleges that the manufacturing process used to create Defendant's ADXL366 and similar MEMS accelerometers infringes the claimed method Compl. ¶¶70-73

Multi-Patent Capsule: U.S. Patent No. 8,395,252

• Patent Identification: U.S. Patent No. 8,395,252, "Integrated MEMS and CMOS package and Method," issued March 12, 2013 Compl. ¶24
• Technology Synopsis: This patent details a specific packaging apparatus for integrating MEMS devices with ICs. The structure involves bonding a semiconductor substrate (containing ICs) to a larger substrate member, placing a MEMS device on the IC substrate, and covering it with an enclosure '252 Patent, abstract A key aspect is the placement of external bonding structures within defined "first outer region" and "second outer region" on the upper surface, which have specific width limitations (e.g., <200 microns and <100 microns, respectively) to achieve a compact footprint '252 Patent, col. 5:27-44 '252 Patent, cl. 1
• Asserted Claims: The complaint asserts independent claim 1 Compl. ¶94
• Accused Features: The complaint alleges that the physical layout and packaging architecture of the ADXL366 product line, including its substrate arrangement and placement of bonding pads, infringes the claimed apparatus Compl. ¶¶92 Compl. ¶95

III. The Accused Instrumentality

Product Identification

The complaint identifies Defendant's MEMS-based sensor products, with a focus on the ADA4571 Integrated AMR Angle Sensor, the ADXL366 Micropower 3-Axis Digital Output MEMS Accelerometer, and other similar products such as the ADXL362, ADXL367, ADXL355, and ADA4570 Compl. ¶29 Compl. ¶34 Compl. ¶52

Functionality and Market Context

The accused products are semiconductor components sold by Defendant, a self-described "global semiconductor leader" (Compl. ¶7). The ADA4571 is an anisotropic magnetoresistive (AMR) sensor that produces analog outputs indicating the angular position of a surrounding magnetic field and is packaged with a separate amplifier die Compl. p. 9 The ADXL366 is an ultra-low-power, 3-axis digital accelerometer with embedded motion detection, designed for applications such as wearable devices and asset tracking Compl. ¶73 Compl. ¶95 The complaint provides a screenshot from Defendant's website showing the ADA4571 is available for purchase in the United States Compl. ¶31 Compl. p. 7 The complaint also includes a screenshot showing the ADXL366 product is available for purchase through Defendant's website Compl. ¶30 Compl. p. 6

IV. Analysis of Infringement Allegations

'666 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
An integrated electronic compass and circuit system	The accused ADA4571 is alleged to be an integrated compass and circuit system.	¶37	col. 2:35-36
comprising: a semiconductor substrate;	The complaint provides an optical image from a reverse-engineered device, identifying a semiconductor substrate. This image shows the foundational layer of the chip package Compl. ¶38 Compl. p. 10	¶38	col. 4:20-22
one or more CMOS integrated circuits formed on one or more portions of the semiconductor substrate; and	An annotated optical image from the reverse-engineered device is presented to show CMOS integrated circuits on the substrate. The image highlights the complex circuitry fabricated on the die Compl. ¶39 Compl. p. 11	¶39	col. 4:51-54
an electronic compass device operably coupled to the one or more CMOS integrated circuits.	A reverse-engineered image of a decap-ed package shows the electronic compass device die wire-bonded to the CMOS integrated circuit die, alleging they are operably coupled.	¶40	col. 2:41-42

• Identified Points of Contention:
  • Scope Question: The primary point of contention may be definitional. The complaint alleges the accused ADA4571, an "anisotropic magnetoresistive (AMR) sensor," constitutes an "electronic compass device" '666 Patent, cl. 1 Compl. ¶37 Compl. p. 9 The defense may argue that the patent, titled "Magneto Meter Using Lorentz Force," is limited to that specific technology and does not cover AMR sensors. This raises the question of whether the term "electronic compass device" as used in the patent can be construed to read on the accused AMR angle sensor.

'560 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
An integrated sensor device or electronic device...	The accused ADXL366 is identified as an "ultralow-power, 3-axis digital accelerometer," which is alleged to be an integrated sensor device.	¶55	col. 4:1-10
a substrate member having a first surface region, the substrate member having at least one contact region;	The complaint provides an annotated scanning electron microscope (SEM) image from a reverse-engineered device identifying the substrate member, its surface, and a contact region.	¶56	col. 4:40-42
at least one singulated integrated sensor or electronic device each coupled to a die member, each die member having a singulated surface region and at least one contact region, the singulated surface region(s) being coupled to the first surface region;	An annotated optical image is used to identify the "singulated integrated sensor" and the "die member" to which it is coupled.	¶57	col. 5:35-40
at least one first conductive material formed overlying at least the contact region(s) of the singulated integrated sensor or electronic device; and	An annotated optical image highlights a "first conductive material" on the contact region of the sensor device.	¶58	col. 5:2-10
at least one second conductive material formed overlying at least a portion of the first conductive material(s).	An annotated X-ray image is presented to show a "second conductive material" formed over the first, illustrating the layered connection. This side-view X-ray highlights the vertical build-up of the interconnection Compl. ¶59 Compl. p. 18	¶59	col. 6:11-16

• Identified Points of Contention:
  • Technical Question: The infringement analysis may focus on the term "singulated surface region." The claim requires this specific surface of the die member to be "coupled to the first surface region" of the substrate, which the patent specification links to a vertical mounting orientation '560 Patent, col. 5:32-48 The key question will be one of physical structure: does the accused product's assembly involve a "singulated surface region" being coupled to the substrate in the manner required by the claim, or does it use a more conventional packaging configuration?

V. Key Claim Terms for Construction

For the '666 Patent:

• The Term: "electronic compass device"
• Context and Importance: The definition of this term is central to the infringement analysis for the '666 Patent. The accused product is an "AMR angle sensor," while the patent's specification heavily discusses a "Lorentz force based magnetic sensor" '666 Patent, col. 6:15-16 Compl. p. 9 The case may turn on whether the claimed term is broad enough to cover the accused technology.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification discusses the integration of various MEMS devices, including a generic "magnetic sensor," not exclusively a Lorentz force type '666 Patent, col. 4:5-9 The claim itself does not contain the "Lorentz force" limitation.
  • Evidence for a Narrower Interpretation: The patent's title is "Magneto Meter Using Lorentz Force For Integrated Systems." The detailed description of the preferred embodiment focuses almost exclusively on the principles and structures of a Lorentz force sensor '666 Patent, title '666 Patent, col. 6:15-67 This may suggest the invention is limited to that specific implementation.

For the '560 Patent:

• The Term: "singulated surface region"
• Context and Importance: This term is critical to defining the novel vertical mounting structure. Infringement depends on whether the accused product's die has a surface, created by singulation (cutting), that is then used as the interface for coupling to the substrate. Practitioners may focus on this term because it distinguishes the invention from conventional die-attach methods.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party could argue "singulated surface region" simply refers to any surface of a die that has been separated from a wafer.
  • Evidence for a Narrower Interpretation: The specification describes a process where a saw cuts the die, creating a "singulated surface region (203) on the side of a saw kerf (202)," and states this specific surface "is used for mounting the die member vertically on a substrate" '560 Patent, col. 5:32-48 '560 Patent, Fig. 2 This suggests "singulated surface region" refers specifically to the newly created side surface used for the vertical connection.

VI. Other Allegations

• Indirect Infringement: For all asserted patents, the complaint alleges induced infringement under 35 U.S.C. § 271(b). The allegations are based on Defendant allegedly contracting for the manufacture of the accused products and providing them to third-party distributors, customers, and end-users with the specific intent to cause infringement Compl. ¶43 Compl. ¶62 Compl. ¶83 Compl. ¶103
• Willful Infringement: The complaint alleges willful infringement for all four patents. The basis for this allegation is Defendant's alleged pre-suit and post-suit knowledge of infringement. Pre-suit knowledge is alleged to have been established by a notice letter sent on April 7, 2026, and post-suit knowledge by the service of the complaint itself Compl. ¶43 Compl. ¶45 Compl. ¶62 Compl. ¶82 Compl. ¶103

VII. Analyst's Conclusion: Key Questions for the Case

This case presents a multi-faceted dispute over the architecture and fabrication of modern MEMS sensors. The litigation will likely center on the following key questions:

1. A core issue will be one of definitional scope: for the '666 patent, can the term "electronic compass device", which is described in the patent's preferred embodiment as a Lorentz force sensor, be construed broadly enough to cover the "anisotropic magnetoresistive (AMR) sensor" technology used in the accused ADA4571 product?

2. A second central question will be one of structural interpretation: for the '560 patent, does the accused product's packaging embody the specific "vertical mounting" structure claimed, particularly the coupling of a "singulated surface region" of the sensor die to the substrate, or does it utilize a conventional packaging architecture that falls outside the claim scope?

3. An evidentiary question will be critical for the method patents ('312 and '252): can the Plaintiff demonstrate, likely through complex reverse engineering and expert testimony, that Defendant's products are necessarily made using the specific fabrication and packaging steps recited in the method claims, including the formation of a "substantially circular" anchor arrangement ('312 patent) and the use of specific, dimensionally-constrained packaging regions ('252 patent)?