Sheldahl PCB Materials: Complete Guide to Flexible Circuit Laminates & Coverlays

Looking for reliable flexible circuit materials that can handle extreme temperatures, harsh chemicals, and demanding applications? Sheldahl PCB materials have been the go-to choice for aerospace, automotive, and medical applications for over 65 years. This guide breaks down everything you need to know about Sheldahl’s laminate and coverlay options.

What is Sheldahl and Why Does It Matter?

If you’ve worked with flex circuits long enough, you’ve probably come across Sheldahl materials at some point. Sheldahl Flexible Technologies, now a subsidiary of Flex Ltd., has been manufacturing flexible printed circuit materials since the 1950s. They literally made the first flexible circuit used in a production vehicle—the 1965 Ford Thunderbird.

What sets Sheldahl PCB materials apart from competitors is their proprietary vacuum deposition process. Instead of using traditional adhesive bonding to attach copper to polyimide film, Sheldahl deposits copper directly onto the substrate. This adhesiveless approach eliminates a potential failure point and allows the material to perform better under thermal stress.

The company also played a critical role in the James Webb Space Telescope project, developing the sunshield material that protects sensitive electronics from extreme space temperatures. When NASA trusts your materials for a $10 billion telescope, that says something about quality.

Sheldahl’s manufacturing capabilities are impressive. They can process substrates as thin as 1.5 micrometers or up to 350 micrometers thick. Standard roll widths are typically 12 inches (305mm) or 24 inches (610mm), making the materials well-suited for high-volume roll-to-roll production. This flexibility in formats allows engineers to specify exactly what they need for their particular application.

Types of Sheldahl PCB Materials

Sheldahl offers two main categories of flexible circuit materials: adhesiveless laminates and adhesive-based laminates. Each has its place depending on your application requirements.

Novaclad® Adhesiveless Laminates

Novaclad is Sheldahl’s flagship adhesiveless laminate product line. The material uses vacuum deposition to bond thin copper directly to polyimide film, creating a two-layer structure without any adhesive layer in between.

Key variants include:

• Novaclad G2200: Standard adhesiveless laminate for general high-performance applications
• Novaclad G2300: Halogen-free version for applications requiring environmental compliance
• Novaclad HDI: High-density interconnect version with fine-line capability and laser-drilled micro-vias

Novaclad has passed long-term heat aging tests of 1,000 hours at 150°C—pretty impressive when you consider that many adhesive-based materials start degrading well before that threshold. Millions of vehicles on the road today use circuits fabricated on Novaclad for under-the-hood applications.

Adhesive-Based Laminates

For applications where cost is more critical than extreme thermal performance, Sheldahl offers adhesive-based laminates. These use either acrylic or epoxy adhesives to bond copper foil to polyimide film.

• G1932: Polyimide copper laminate with flame-retardant epoxy adhesive, RoHS compliant
• Acrylic-based options: Available for applications requiring different processing characteristics

Coverlay Materials

Sheldahl’s coverlay products protect etched circuit traces from environmental damage and provide electrical insulation. The most common options include:

• T1647: Polyimide coverlay with flame-retardant acrylic adhesive. Service temperature up to 150°C. Meets IPC 4203/1 specifications.
• T1612 Series: Polyimide film with non-flame-retardant acrylic adhesive for applications where FR rating isn’t required
• BusBond: Insulation materials specifically designed for laminated busbar applications

Q-Prime® Thermal Management Solutions

For LED and high-current applications where heat dissipation is critical, Sheldahl PCB offers Q-Prime technology. This proprietary thermal adhesive system has been used in automotive LED lighting for over 30 years.

Q-Prime enables attached components to run at cooler temperatures than traditional flex constructions. It’s well-suited for automotive headlamps, fog lamps, DRLs, indicators, and HUDs. The flexible circuit format also allows more design freedom compared to rigid metal-core PCBs.

Sheldahl PCB Material Specifications

The following table summarizes key specifications for Sheldahl’s primary laminate and coverlay products:

Product	Type	Max Temp	Key Features
Novaclad G2200	Adhesiveless Laminate	150°C	High flexibility, fine features
Novaclad G2300	Adhesiveless (Halogen-Free)	150°C	RoHS compliant, eco-friendly
Novaclad HDI	High-Density Interconnect	150°C+	Micro-vias, fine-line circuitry
T1647 Coverlay	Polyimide Coverlay	150°C	FR acrylic adhesive, IPC 4203/1
G1932 Laminate	Adhesive-Based	105°C	FR epoxy, cost-effective
Q-Prime	Thermal Management	Varies	Heat dissipation for LEDs

Note: Specifications may vary by specific product configuration. Always consult Sheldahl’s official datasheets for your exact application requirements.

Key Properties of Sheldahl Materials

When evaluating Sheldahl PCB materials against alternatives like DuPont Pyralux or other flexible laminates, several properties stand out:

Thermal Performance

Heat can easily pass through Sheldahl flexible circuit materials due to their excellent thermal conductivity. The adhesiveless construction of Novaclad eliminates the weak link in traditional laminates—the adhesive layer often degrades first under thermal stress. This makes Sheldahl materials ideal for under-the-hood automotive applications, aerospace systems, and any environment with significant temperature cycling.

Dimensional Stability

Sheldahl’s manufacturing process ensures consistent dimensional stability across their product lines. This is critical for high-density circuits where even small dimensional changes during processing can affect registration and yield. The typical dimensional stability values meet or exceed IPC requirements.

Chemical Resistance

Chemical resistance is a crucial property because many flex circuits function in environments exposed to various chemicals—fuels, solvents, cleaning agents, and other industrial fluids. Sheldahl materials maintain their mechanical and electrical properties even after extended chemical exposure.

Bond Strength

The vacuum deposition process used for Novaclad creates an exceptionally strong copper-to-polyimide bond. This high peel strength means the copper traces won’t delaminate under thermal cycling, mechanical stress, or during the PCB fabrication process itself.

Industry Applications

Sheldahl PCB materials serve demanding applications across multiple industries. Here’s where you’ll commonly find them:

Industry	Typical Applications
Automotive	LED headlamps, infotainment systems, transmission controls, EV battery management, seat sensors
Aerospace & Defense	Satellite electronics, thermal control systems, avionics, military communications
Medical	X-ray machines, CT scanners, heart rate monitors, wearable medical devices, surgical tools
Consumer Electronics	Smartphones, wearables, cameras, displays, touch sensors
Industrial	HMI interfaces, heaters, smart packaging, agricultural lighting systems

For EV applications specifically, flexible printed circuits from Sheldahl interconnect battery cells, inverters, DC-DC converters, and on-board chargers. The flexible nature allows circuits to flex during charging cycles while providing reliable electrical connections.

In the medical field, Sheldahl materials are commonly integrated into CT scanners, X-ray machines, heart rate monitors, and wearable monitoring devices. The combination of chemical resistance, dimensional stability, and the ability to conform to complex shapes makes flex circuits ideal for space-constrained medical instruments where reliability cannot be compromised.

Read more PCB Raw Materials:

Sheldahl vs. Competitors

How does Sheldahl PCB material stack up against alternatives like DuPont Pyralux? Here’s a practical comparison:

Criteria	Sheldahl Novaclad	DuPont Pyralux AP
Construction	Adhesiveless (vacuum deposited)	Adhesiveless (all-polyimide)
Thermal Rating	150°C continuous	Up to 250°C+ (Pyralux HT)
Best For	Dynamic flex, automotive, HDI	High-temp, rigid-flex, multilayer
Availability	Roll form standard	Sheets and rolls
Market Focus	Automotive, aerospace, LED	Broad market coverage

Both are excellent materials. DuPont has broader global distribution and a wider product range (especially for extreme temperature applications). Sheldahl excels in roll-to-roll processing and has deep automotive expertise. Your choice often comes down to specific application requirements and supply chain preferences.

From a practical standpoint, many PCB fabricators stock both material lines and can advise based on your specific requirements. If you’re designing for automotive OEMs who already have qualified Sheldahl materials in their supply chain, sticking with that ecosystem simplifies qualification. The same applies in reverse for designs targeting DuPont-centric supply chains.

How to Select the Right Sheldahl Material

Choosing the right Sheldahl PCB material comes down to understanding your application requirements. Here’s a practical decision framework:

Consider Operating Temperature

If your circuit will see sustained temperatures above 105°C, go adhesiveless (Novaclad). For moderate temperature applications, adhesive-based laminates offer cost savings without sacrificing reliability.

Evaluate Flex Requirements

Dynamic flex applications (repeated bending during operation) benefit from adhesiveless construction. Static flex or flex-to-install applications can use either type.

Check Line Width Requirements

Need fine features below 75 microns? Novaclad HDI with its mSAP (modified semi-additive process) capability is your best option. Standard applications can use conventional Novaclad or adhesive-based materials.

Consider Thermal Management Needs

High-power LEDs or other heat-generating components? Q-Prime technology specifically addresses thermal management. For standard circuits without significant heat dissipation needs, regular laminates work fine.

Useful Resources and Downloads

Here are official resources for Sheldahl PCB materials:

Official Sheldahl Website: www.sheldahl.com

Flexible Printed Circuit Materials: Product Selector Guide

Novaclad Technical Data: GlobalSpec Datasheets

IPC Standards Reference: IPC-4204 Flexible Metal-Clad Dielectrics

Distributors: Holders Technology (Europe) | Rico Products (Americas)

Contact Sheldahl directly: Phone: +1 (507) 663-8344 | Email: electronicmaterials@multek.com

Frequently Asked Questions

What is the difference between Sheldahl Novaclad and adhesive-based laminates?

Novaclad uses vacuum deposition to bond copper directly to polyimide film without any adhesive layer. This adhesiveless construction provides better thermal performance (rated to 150°C), superior dimensional stability, and improved reliability under dynamic flex conditions. Adhesive-based laminates cost less but have lower temperature ratings and may not perform as well in demanding applications.

Is Sheldahl PCB material suitable for high-frequency applications?

Yes. Novaclad’s smooth copper surface (achieved through the deposition process) makes it suitable for high-frequency signal propagation. The material has been used in wireless communications and high-speed digital applications. For specific dielectric constant and loss tangent values at your operating frequency, consult Sheldahl’s technical datasheets.

What IPC standards do Sheldahl materials meet?

Sheldahl laminates conform to IPC-4204 (Flexible Metal-Clad Dielectrics for Use in Fabrication of Flexible Printed Boards). Coverlay materials like T1647 meet IPC-4203/1 requirements. The company also maintains ISO, QS, and TS16949 quality certifications for automotive applications.

Can Sheldahl materials be processed with standard flex PCB fabrication equipment?

Yes. Sheldahl materials are designed to be processed using standard flexible circuit manufacturing procedures. The laminates are available in roll form for high-volume production. Coverlay lamination follows typical platen press parameters (365-385°F, 300-400 PSI, 50-60 minutes).

Where can I buy Sheldahl PCB materials?

Sheldahl materials are available through authorized distributors globally. In the Americas, Rico Products is a key distributor. In Europe, Holders Technology carries the product line. For large volume or custom requirements, contact Sheldahl directly. Many PCB fabricators (like Cirexx) also stock Sheldahl materials and can fabricate circuits for you.

Processing and Fabrication Tips

When working with Sheldahl PCB materials, there are several fabrication considerations to keep in mind:

Lamination Parameters

For T1647 coverlay lamination, typical platen press parameters are 365-385°F (185-195°C) at 300-400 PSI for 50-60 minutes. Always oven-dry coverlay at 250-275°F for at least one hour before solder exposure to prevent delamination issues caused by trapped moisture.

Storage and Handling

Sheldahl materials should be stored in their original unopened containers at normal interior temperatures. Polyimide-based materials are hygroscopic—they absorb moisture from the air. If materials have been exposed to ambient conditions, baking before processing is recommended.

Quality Certifications

Sheldahl Flexible Technologies maintains ISO quality certifications and meets TS16949 standards for automotive applications. Their materials are manufactured using quality systems that conform to rigorous industry standards, which is particularly important for aerospace and medical device applications where traceability and process control are mandatory.

Final Thoughts

Sheldahl PCB materials have earned their reputation through decades of real-world performance in demanding applications. From the first flex circuit in a production vehicle to the sunshield protecting the James Webb Space Telescope, Sheldahl’s track record speaks for itself.

If you’re designing flex circuits for automotive, aerospace, medical, or other high-reliability applications, Sheldahl materials deserve serious consideration. Their adhesiveless Novaclad line offers excellent thermal and mechanical properties, while their coverlay and specialty products round out a complete material solution.

For specific applications, I’d recommend reaching out to Sheldahl’s technical team or one of their authorized distributors. They can help match the right material to your requirements and provide samples for qualification testing.

The bottom line: whether you’re designing automotive LED systems, aerospace electronics, medical devices, or consumer wearables, understanding your material options is the first step toward a successful flex circuit design. Sheldahl’s 65+ years of experience in flexible technology provides a solid foundation for even the most demanding applications.