From Wafer to Panel: The Role of Large-Area PVD in Advanced Packaging

As semiconductor devices continue to evolve for artificial intelligence (AI), high-performance computing (HPC), chiplets, and high-bandwidth memory (HBM), advanced packaging is becoming increasingly important.

For decades, semiconductor manufacturing has been built around wafer-based processing, with 200 mm and 300 mm wafers serving as mature manufacturing platforms. However, as package sizes increase and interconnect density continues to rise, the industry is exploring larger-format approaches to semiconductor packaging.

One of the most closely watched developments is Panel-Level Packaging (PLP).

Rather than relying exclusively on circular wafers, panel-level processing uses larger rectangular substrates to process multiple packages over a larger area. The objective is not simply to make the substrate larger, but to explore whether larger-area processing can improve manufacturing efficiency, throughput, and cost while maintaining the yield and process control required for advanced packaging.

This transition creates new challenges for semiconductor equipment manufacturers, particularly in thin-film deposition. This is where large-area PVD sputtering becomes increasingly important.

From Wafer to Panel: The Evolution of Advanced Packaging

For decades, wafer-based processing has been the foundation of semiconductor manufacturing. The mature 200 mm and 300 mm wafer platforms have enabled highly controlled and repeatable manufacturing across the semiconductor industry.

Advanced packaging, however, is introducing new requirements. AI processors, HPC devices, chiplets, and high-bandwidth memory increasingly require higher interconnect density, larger package dimensions, and more sophisticated redistribution structures.

These requirements have encouraged the development of multiple advanced packaging architectures, including Fan-Out Packaging, Fan-Out Panel-Level Packaging (FOPLP), 2.5D and 3D integration, chiplet-based architectures, and emerging glass-based packaging technologies.

Panel-Level Packaging is therefore not simply about replacing wafers with panels. Instead, it represents an additional manufacturing approach that may offer advantages for specific advanced packaging applications.

Why Is Panel-Level Packaging Gaining Attention?

One of the fundamental attractions of panel-level processing is its larger manufacturing area.

A larger panel can potentially contain more individual packages than a conventional wafer. If process uniformity and yield can be maintained, the larger processing area may improve manufacturing efficiency and reduce the effective cost per package.

However, the economic advantage of PLP is not determined by substrate area alone. Actual manufacturing economics depend on package layout, substrate utilization, process throughput, cycle time, yield, equipment utilization, and downstream process compatibility.

This means that wafer-level and panel-level manufacturing are likely to coexist, with different architectures being selected according to technical and economic requirements.

PLP is attracting particular attention in areas such as:

• Fan-Out Packaging
• Fan-Out Panel-Level Packaging (FOPLP)
• Redistribution Layers (RDL)
• Chiplet-based architectures
• Large-package advanced integration
• Glass-based packaging
• Emerging semiconductor substrate technologies

The Role of PVD in Panel-Level Packaging

Physical Vapor Deposition (PVD) is an important thin-film technology used throughout semiconductor manufacturing and advanced packaging.

Magnetron sputtering is particularly relevant for depositing metallic, adhesion, and barrier films required by different packaging architectures.

Depending on the process flow, PVD may be used for:

• Adhesion layers
• Barrier layers
• Copper seed layers
• Conductive films
• Redistribution-layer metallization
• Other functional thin-film structures

A simplified metallization sequence can be represented as:

Substrate Preparation → Surface Treatment → Adhesion / Barrier Layer → Cu Seed Layer → Electroplating → Pattern Formation → Subsequent Packaging Processes

The exact sequence varies according to the packaging architecture and materials used. The fundamental role of PVD, however, is to establish a controlled and uniform thin-film structure that enables subsequent semiconductor processing.

Challenges of Large-Area PVD

Scaling a PVD system from wafer processing to panel processing is not simply a matter of building a larger vacuum chamber.

The complete deposition environment must be reconsidered as substrate dimensions increase.

Large-area sputtering requires coordinated control of:

• Plasma distribution
• Magnetic field distribution
• Gas flow
• Process pressure
• Target configuration
• Target-to-substrate distance
• Substrate temperature
• Substrate movement
• Bias conditions
• Deposition rate

Plasma Distribution

Magnetron sputtering relies on controlled plasma generation near the sputtering target. For larger substrates, plasma distribution must be carefully controlled across the entire processing area.

Variations in plasma density can directly affect deposition rate, film thickness, and film properties.

Gas Distribution

Process gases must be distributed consistently throughout the chamber. Uneven gas flow can create local variations in plasma conditions and deposition behavior.

Thermal Management

Thin-film properties can be sensitive to substrate temperature. As panel size increases, maintaining thermal uniformity across the processing area becomes increasingly important.

Target and Magnetron Design

Large-area deposition requires careful optimization of target geometry, magnetron configuration, magnetic field distribution, and target utilization. These parameters directly influence plasma density and deposition uniformity.

Film Uniformity, Throughput and Process Control

For advanced packaging applications, achieving the target average film thickness is not sufficient.

Engineers must also understand how film thickness and electrical properties vary from the center of the panel to its edges and corners.

For example, if the nominal film thickness is 100 nm, the critical question is not simply whether the average thickness reaches 100 nm. The process must also maintain the required uniformity across the complete active area.

Film uniformity can influence:

• Sheet resistance
• Electroplating behavior
• Film adhesion
• Electrical continuity
• Interconnect reliability
• Overall process yield

Large-area PVD therefore requires optimization of the complete process window, including target geometry, magnetron configuration, gas distribution, process pressure, substrate temperature, bias conditions, substrate movement, and deposition rate.

The challenge is not to optimize one parameter independently, but to achieve a stable combination of parameters that provides uniformity, repeatability, and commercially viable throughput.

Throughput Is Equally Important

Panel-level packaging is ultimately driven by manufacturing economics. A PVD process with excellent film uniformity but insufficient throughput may not provide a commercially attractive solution.

Conversely, a high-throughput process with unstable film properties can negatively affect downstream yield.

Commercial PLP PVD equipment therefore needs to balance:

Uniformity + Throughput + Yield + Process Stability + Cost of Ownership

From 300 mm Wafers to 600 × 600 mm Panels

The difference in processing area becomes particularly clear when comparing a 300 mm wafer with a 600 × 600 mm panel.

A 300 mm wafer has a geometric area of approximately 70,686 mm².

A 600 × 600 mm panel provides a geometric area of 360,000 mm².

In purely geometric terms, the panel therefore provides approximately 5.1 times the area of a 300 mm circular wafer.

This does not mean that a 600 × 600 mm panel automatically delivers five times the production capacity. Actual productivity depends on package layout, edge exclusion, substrate utilization, process cycle time, equipment throughput, and yield.

Nevertheless, the comparison illustrates why larger-area processing is attracting attention in advanced packaging.

For equipment manufacturers, the challenge is therefore not simply to increase equipment dimensions. The challenge is to scale the process capability while maintaining semiconductor-grade process control.

PVD for RDL, Cu Seed, TGV and Glass Core

RDL Metallization

Redistribution layers are increasingly important in advanced packaging. PVD can provide conductive and adhesion structures that support subsequent metallization processes.

Copper Seed Layer

Copper electroplating generally requires an electrically conductive seed layer. Depending on the process architecture, PVD sputtering can be used to deposit the required seed structure.

Film uniformity, adhesion, electrical resistance, and surface condition become particularly important because variations in the seed layer can influence downstream plating performance.

TGV Metallization

Through-Glass Via (TGV) technology is attracting increasing interest for glass-based advanced packaging and interconnect structures.

TGV introduces additional challenges because the surface is no longer purely planar. High-aspect-ratio structures can create difficulties for conventional line-of-sight deposition.

For TGV metallization, the required deposition profile depends strongly on via diameter, glass thickness, aspect ratio, and the target metallization architecture. Conventional sputtering may provide sufficient surface and partial sidewall coverage for some structures, while higher-aspect-ratio vias may require optimized ionization, substrate bias, pressure, geometry, or other process strategies to improve coverage.

Glass Core Substrates

Glass core technology is another emerging direction in advanced packaging. Glass substrates offer several potentially attractive properties for semiconductor packaging, including dimensional stability and electrical characteristics.

As glass-based packaging develops, large-area metallization becomes an important equipment requirement.

This creates a natural connection between:

Glass Core → TGV → Metallization → RDL → Advanced Packaging

These applications also demonstrate why a flexible large-area PVD platform can be more valuable than a machine designed for only one packaging process.

The Future of Large-Area Semiconductor PVD

The future of advanced packaging is unlikely to be defined by a single manufacturing platform.

300 mm wafer processing will remain essential for many semiconductor applications. At the same time, panel-based manufacturing is expected to continue developing for applications where larger substrate areas can provide meaningful manufacturing and economic advantages.

For equipment manufacturers, this creates a new engineering frontier.

The question is no longer simply:

Can we deposit a thin film?

The more important question is:

Can we deposit a highly uniform, repeatable, and process-controlled thin film across a large semiconductor panel at commercially viable throughput?

This is the fundamental challenge of large-area semiconductor PVD.

Future equipment development is therefore likely to focus increasingly on:

• Larger substrate formats
• Improved film uniformity
• Higher throughput
• Better target utilization
• Advanced plasma control
• Lower particle generation
• Automated process control
• In-line metrology
• Recipe management
• Data-driven process optimization

SIMVACO’s 600 × 600 mm Panel-Level PVD Capability

SIMVACO is developing its PVD technology toward the emerging requirements of large-area advanced semiconductor packaging.

One of the company's current capabilities is a 600 × 600 mm panel-level advanced packaging PVD platform, designed for large-area thin-film deposition applications.

The platform focuses on key requirements associated with panel-level semiconductor processing, including:

• Large-area sputtering
• Thin-film uniformity
• Plasma and process control
• Stable vacuum conditions
• Panel handling
• Process repeatability
• Integration with advanced packaging process flows

The development of a 600 × 600 mm platform represents an important step beyond conventional wafer-scale sputtering.

More importantly, SIMVACO views large-area PVD as a platform technology rather than a single-purpose machine. The same core equipment architecture can potentially support different advanced packaging applications according to process requirements.

These applications include:

• Panel-Level Packaging
• RDL Metallization
• Copper Seed Layer Deposition
• TGV Metallization
• Glass Core Substrates
• Other emerging large-area semiconductor thin-film processes

As advanced packaging moves toward larger formats and increasingly complex architectures, the ability to control thin-film deposition across large substrates will become increasingly important.

SIMVACO is continuing to develop its large-area PVD technology to support this evolution—from wafer-scale processing toward the emerging requirements of panel-level semiconductor manufacturing.

As advanced packaging moves toward larger substrates and higher interconnect density, large-area PVD will play an increasingly important role in enabling controlled, repeatable thin-film deposition for next-generation packaging architectures.