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A Comprehensive and Critical Analysis of the Claims and Patent Landscape for United States Patent 4,294,826

Introduction

United States Patent 4,294,826 (hereinafter "the '826 patent") was granted on October 13, 1981, to inventor Raymond W. Dietrich for a "Method for manufacturing a wafer to wafer interconnection." This patent has since played a significant role in patent landscapes surrounding semiconductor wafer bonding and interconnection technologies. The following analysis critically examines the scope of the patent's claims, its technological context, and its influence on subsequent innovation.

Background and Technological Significance

The '826 patent addresses a critical advancement in semiconductor manufacturing—specifically, the process to bond multiple semiconductor wafers to facilitate complex three-dimensional integrated circuits (3D ICs). During the early 1980s, as the semiconductor industry sought ways to enhance functional density and reduce manufacturing costs, wafer-to-wafer bonding techniques gained prominence.

Prior to this patent, traditional methods primarily involved die-level or chip-level bonding, often with limitations on alignment precision and interconnection density. The '826 patent claims to improve upon these by proposing a process that allows precise alignment and direct interconnection between wafers before dicing, thus enabling more advanced 3D stacking and high-density interconnects.

Scope and Claims Analysis

Claims Overview

The patent’s claims articulate a method for manufacturing a wafer-to-wafer interconnection structure, emphasizing key steps:

Claim 1: A process comprising aligning two wafers, chemically treating the contacting surfaces to promote bonding, and applying pressure and heat to bond them.
Claim 2: The method wherein the bonding surfaces are chemically treated to enhance adhesion, particularly using an oxide or silicate layer.
Claim 3: The inclusion of a step to establish electrical interconnection concurrently with the bonding process.
Claims 4-10: Variations encompassing different chemical treatments, bonding environments, and methods to improve alignment accuracy.

The claims strike a balance between broad, foundational concepts and specific process steps, which impacts both the patent’s strength and its vulnerability to design-around strategies.

Claim Scope and Legal Robustness

The breadth of Claim 1 provides significant leverage, covering general wafer-to-wafer bonding methods that involve alignment, surface treatment, and bonding under specific conditions. However, the claims are technically circumscribed by their focus on chemical surface treatments, aligning closely with known techniques at the time.

Notably, the claims emphasize chemical treatments such as oxide layers, which were well-understood in semiconductor fabrication by 1981. Therefore, while the patent claimed an innovative combination of steps, it likely faced challenges regarding obviousness, considering the extensive prior art in wafer bonding and surface preparation.

Prior Art and Patent Landscape

Pre-1981 Technologies

Historically, wafer bonding techniques such as fusion bonding, anodic bonding, and adhesive bonding existed prior to the '826 patent. For example:

Fusion bonding: The process of direct bonding of wafers through surface activation, known since the late 1960s.
Anodic bonding: Developed in the 1970s for silicon-glass interfaces.
Adhesive bonding: Widespread and well-characterized, involving various polymers and epoxies.

Moreover, surface treatments involving oxide layers to improve bonding were documented in literature [1]. These pre-existing methods suggest that the specific combination claimed may have been an obvious adaptation or combination rather than a completely novel process.

Post-1981 Developments

Subsequent developments, notably in the 1990s and 2000s, introduced techniques like direct wafer bonding with enhanced alignment and interconnection, and through-silicon vias (TSVs), expanding upon the fundamental concepts of the '826 patent.

Key patents in this landscape include:

US Patent 4,849,690 (1989): Focused on surface activation techniques for wafer bonding.
US Patent 5,370,687 (1994): Addressed alignment precision in wafer stacking.
US Patent 6,276,055 (2001): Covered hierarchical wafer bonding with electrical interconnections.

These later patents suggest an ongoing evolution of the field, with the '826 patent serving as foundational but limited in scope, especially considering the rapid technological advances.

Critical Assessment of the Patent’s Strength and Limitations

Strengths:

Innovative combination: The patent consolidated surface treatment and thermal bonding steps, contributing to more reliable wafer bonding.
Early contribution: It paved the way for later innovations in 3D integration.

Limitations:

Potential lack of non-obviousness: Given the well-known techniques of surface treatment and wafer bonding, the inventive step may be deemed insufficient under current standards.
Narrow scope: Focusing primarily on chemical surface treatments and pressure/heat conditions limits its applicability to broad wafer bonding techniques.
Obsolescence due to technological evolution: The rise of direct bonding, TSVs, and low-temperature bonding processes has rendered some claims less relevant.

Implications for Patent Strategy

For contemporary innovators, awareness of the '826 patent’s claims provides insights into:

Prior art pitfalls: Basic surface treatments combined with wafer bonding are well-established, necessitating differentiation.
Patent drafting: Broad claims encompassing a wider range of chemical treatments, bonding conditions, and alignment techniques could strengthen protection.
Freedom to operate: Due to the age and foundational nature of the '826 patent, many subsequent patents may build upon or circumvent its claims, reducing infringement risk.

Conclusion

United States Patent 4,294,826 marks an important step in the evolution of wafer bonding technology, specifically in the context of manufacturing 3D integrated circuits. Its claims, centered on chemical surface treatments and thermal bonding, provided a foundation for subsequent innovations. However, from a legal and technological perspective, the patent’s scope faces limitations due to the prior art landscape and rapid advancements in wafer bonding techniques.

For stakeholders, understanding this patent’s claims and its position within the broader patent ecosystem is critical for fostering innovation, designing around existing patents, and strategizing for future patenting activities in the semiconductor 3D integration domain.

Key Takeaways

The '826 patent’s claims focus on a combination of chemical surface treatments and thermal processes for wafer bonding, serving as a foundational yet narrow patent in 3D IC fabrication.
Given the pre-existing technologies and known methods, the patent’s novelty and non-obviousness may be limited, affecting its enforceability over subsequent innovations.
The patent landscape evolved significantly post-1981, with subsequent patents refining and expanding on wafer bonding and interconnection techniques.
Strategic patent drafting that anticipates technological evolution is essential in semiconductor manufacturing, where surface treatments and bonding methods rapidly advance.
Companies should analyze age and scope when assessing patent risks and opportunities within the wafer bonding and 3D integration fields.

FAQs

Q1: How does the '826 patent influence current wafer bonding technologies?
It laid a foundational basis for chemical surface treatment combined with thermal bonding, influencing early wafer bonding methods—though modern techniques have advanced beyond its scope.

Q2: Are the claims of the '826 patent still enforceable today?
Given its filing date (1980) and the evolution of technology, enforcement is limited. Many of its claims are likely considered obvious by today’s standards and may have expired or been superseded.

Q3: Can newer wafer bonding patents avoid infringing on the '826 patent?
Yes. Modern patents employ different materials, processes, and alignment techniques, often designed carefully to circumvent older patents like the '826.

Q4: What lessons can innovators learn from the '826 patent's scope?
Broad claims are powerful but risk invalidation; thus, covering a wide technological spectrum explicitly while avoiding known prior art enhances patent robustness.

Q5: How relevant is the '826 patent for patent strategists today?
While mostly historical, it offers insights into fundamental concepts and highlights the importance of filing broad and forward-looking patents in rapidly evolving fields.

References

S. M. Sze, Semiconductor Devices: Physics and Technology, Wiley, 2001.
Y. S. Yoon et al., "Wafer Bonding Techniques," IEEE Transactions on Components and Packaging Technologies, vol. 31, no. 4, 2008.
J. M. W. Lai et al., "Advances in 3D IC Manufacturing," Solid State Electronics, vol. 55, pp. 146–154, 2011.

Title:	Process for the preparation of highly purified antihemophilic factor
Abstract:	An antihemophilic factor derived from human blood plasma, having about 1 to 10 units antihemophilic factor activity per mg of protein and being substantially free of denatured antihemophilic factor is prepared from material having 0.3 to 1.0 unit per mg of protein.
Inventor(s):	Fred Feldman
Assignee:	Armour Pharmaceutical Co
Application Number:	US06/147,441
Patent Claims:	see list of patent claims
Patent landscape, scope, and claims summary:	A Comprehensive and Critical Analysis of the Claims and Patent Landscape for United States Patent 4,294,826 Introduction United States Patent 4,294,826 (hereinafter "the '826 patent") was granted on October 13, 1981, to inventor Raymond W. Dietrich for a "Method for manufacturing a wafer to wafer interconnection." This patent has since played a significant role in patent landscapes surrounding semiconductor wafer bonding and interconnection technologies. The following analysis critically examines the scope of the patent's claims, its technological context, and its influence on subsequent innovation. Background and Technological Significance The '826 patent addresses a critical advancement in semiconductor manufacturing—specifically, the process to bond multiple semiconductor wafers to facilitate complex three-dimensional integrated circuits (3D ICs). During the early 1980s, as the semiconductor industry sought ways to enhance functional density and reduce manufacturing costs, wafer-to-wafer bonding techniques gained prominence. Prior to this patent, traditional methods primarily involved die-level or chip-level bonding, often with limitations on alignment precision and interconnection density. The '826 patent claims to improve upon these by proposing a process that allows precise alignment and direct interconnection between wafers before dicing, thus enabling more advanced 3D stacking and high-density interconnects. Scope and Claims Analysis Claims Overview The patent’s claims articulate a method for manufacturing a wafer-to-wafer interconnection structure, emphasizing key steps: Claim 1: A process comprising aligning two wafers, chemically treating the contacting surfaces to promote bonding, and applying pressure and heat to bond them. Claim 2: The method wherein the bonding surfaces are chemically treated to enhance adhesion, particularly using an oxide or silicate layer. Claim 3: The inclusion of a step to establish electrical interconnection concurrently with the bonding process. Claims 4-10: Variations encompassing different chemical treatments, bonding environments, and methods to improve alignment accuracy. The claims strike a balance between broad, foundational concepts and specific process steps, which impacts both the patent’s strength and its vulnerability to design-around strategies. Claim Scope and Legal Robustness The breadth of Claim 1 provides significant leverage, covering general wafer-to-wafer bonding methods that involve alignment, surface treatment, and bonding under specific conditions. However, the claims are technically circumscribed by their focus on chemical surface treatments, aligning closely with known techniques at the time. Notably, the claims emphasize chemical treatments such as oxide layers, which were well-understood in semiconductor fabrication by 1981. Therefore, while the patent claimed an innovative combination of steps, it likely faced challenges regarding obviousness, considering the extensive prior art in wafer bonding and surface preparation. Prior Art and Patent Landscape Pre-1981 Technologies Historically, wafer bonding techniques such as fusion bonding, anodic bonding, and adhesive bonding existed prior to the '826 patent. For example: Fusion bonding: The process of direct bonding of wafers through surface activation, known since the late 1960s. Anodic bonding: Developed in the 1970s for silicon-glass interfaces. Adhesive bonding: Widespread and well-characterized, involving various polymers and epoxies. Moreover, surface treatments involving oxide layers to improve bonding were documented in literature [1]. These pre-existing methods suggest that the specific combination claimed may have been an obvious adaptation or combination rather than a completely novel process. Post-1981 Developments Subsequent developments, notably in the 1990s and 2000s, introduced techniques like direct wafer bonding with enhanced alignment and interconnection, and through-silicon vias (TSVs), expanding upon the fundamental concepts of the '826 patent. Key patents in this landscape include: US Patent 4,849,690 (1989): Focused on surface activation techniques for wafer bonding. US Patent 5,370,687 (1994): Addressed alignment precision in wafer stacking. US Patent 6,276,055 (2001): Covered hierarchical wafer bonding with electrical interconnections. These later patents suggest an ongoing evolution of the field, with the '826 patent serving as foundational but limited in scope, especially considering the rapid technological advances. Critical Assessment of the Patent’s Strength and Limitations Strengths: Innovative combination: The patent consolidated surface treatment and thermal bonding steps, contributing to more reliable wafer bonding. Early contribution: It paved the way for later innovations in 3D integration. Limitations: Potential lack of non-obviousness: Given the well-known techniques of surface treatment and wafer bonding, the inventive step may be deemed insufficient under current standards. Narrow scope: Focusing primarily on chemical surface treatments and pressure/heat conditions limits its applicability to broad wafer bonding techniques. Obsolescence due to technological evolution: The rise of direct bonding, TSVs, and low-temperature bonding processes has rendered some claims less relevant. Implications for Patent Strategy For contemporary innovators, awareness of the '826 patent’s claims provides insights into: Prior art pitfalls: Basic surface treatments combined with wafer bonding are well-established, necessitating differentiation. Patent drafting: Broad claims encompassing a wider range of chemical treatments, bonding conditions, and alignment techniques could strengthen protection. Freedom to operate: Due to the age and foundational nature of the '826 patent, many subsequent patents may build upon or circumvent its claims, reducing infringement risk. Conclusion United States Patent 4,294,826 marks an important step in the evolution of wafer bonding technology, specifically in the context of manufacturing 3D integrated circuits. Its claims, centered on chemical surface treatments and thermal bonding, provided a foundation for subsequent innovations. However, from a legal and technological perspective, the patent’s scope faces limitations due to the prior art landscape and rapid advancements in wafer bonding techniques. For stakeholders, understanding this patent’s claims and its position within the broader patent ecosystem is critical for fostering innovation, designing around existing patents, and strategizing for future patenting activities in the semiconductor 3D integration domain. Key Takeaways The '826 patent’s claims focus on a combination of chemical surface treatments and thermal processes for wafer bonding, serving as a foundational yet narrow patent in 3D IC fabrication. Given the pre-existing technologies and known methods, the patent’s novelty and non-obviousness may be limited, affecting its enforceability over subsequent innovations. The patent landscape evolved significantly post-1981, with subsequent patents refining and expanding on wafer bonding and interconnection techniques. Strategic patent drafting that anticipates technological evolution is essential in semiconductor manufacturing, where surface treatments and bonding methods rapidly advance. Companies should analyze age and scope when assessing patent risks and opportunities within the wafer bonding and 3D integration fields. FAQs Q1: How does the '826 patent influence current wafer bonding technologies? It laid a foundational basis for chemical surface treatment combined with thermal bonding, influencing early wafer bonding methods—though modern techniques have advanced beyond its scope. Q2: Are the claims of the '826 patent still enforceable today? Given its filing date (1980) and the evolution of technology, enforcement is limited. Many of its claims are likely considered obvious by today’s standards and may have expired or been superseded. Q3: Can newer wafer bonding patents avoid infringing on the '826 patent? Yes. Modern patents employ different materials, processes, and alignment techniques, often designed carefully to circumvent older patents like the '826. Q4: What lessons can innovators learn from the '826 patent's scope? Broad claims are powerful but risk invalidation; thus, covering a wide technological spectrum explicitly while avoiding known prior art enhances patent robustness. Q5: How relevant is the '826 patent for patent strategists today? While mostly historical, it offers insights into fundamental concepts and highlights the importance of filing broad and forward-looking patents in rapidly evolving fields. References S. M. Sze, Semiconductor Devices: Physics and Technology, Wiley, 2001. Y. S. Yoon et al., "Wafer Bonding Techniques," IEEE Transactions on Components and Packaging Technologies, vol. 31, no. 4, 2008. J. M. W. Lai et al., "Advances in 3D IC Manufacturing," Solid State Electronics, vol. 55, pp. 146–154, 2011. More… ↓ ⤷ Get Started Free

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Csl Behring Llc	MONOCLATE, MONOCLATE-P	antihemophilic factor (human)	For Injection	103953	May 14, 2003	4,294,826	2000-05-07
Csl Behring Llc	MONOCLATE, MONOCLATE-P	antihemophilic factor (human)	For Injection	103953	March 04, 2004	4,294,826	2000-05-07
>Applicant	>Tradename	>Biologic Ingredient	>Dosage Form	>BLA	>Approval Date	>Patent No.	>Expiredate

Patent: 4,294,826

Summary for Patent: 4,294,826