DuPont Pyralux AP9111R: full datasheet specs, RA vs ED copper guide, bend radius math, and real-world PCB applications — from a flex circuit engineer’s perspective.
When you’re designing a flex circuit that will bend thousands of times in service — think printer carriage cables, robotic arm wiring, foldable device interconnects — the material under the copper matters as much as the copper itself. DuPont Pyralux AP9111R is one of the most commonly specified adhesiveless flex laminates for exactly these conditions. It pairs a 1.0 mil (25 µm) all-polyimide dielectric with 35 µm (1 oz/ft²) rolled-annealed copper, no adhesive layer anywhere in the stack. That combination gives you genuine dynamic flex performance, solid current capacity for a flex circuit, and the full thermal profile of the Pyralux AP system — all in an adhesiveless package that processes cleanly with standard flexible circuit fabrication equipment.
This article goes through the complete datasheet, what the product code actually tells you, how 1 oz RA copper changes the design math compared to lighter foils, and where AP9111R ends up in real-world PCB applications.
Decoding the DuPont Pyralux AP9111R Part Number
Every Pyralux AP product code encodes the construction directly. Once you know the system, you can read any configuration in the family without reaching for a catalog.
| Code Segment | Meaning |
| AP | All-Polyimide, adhesiveless construction |
| 91 | 1.0 mil (25 µm) polyimide dielectric |
| 11 | 35 µm copper foil (1.0 oz/ft²) |
| R | Rolled-Annealed (RA) copper foil type |
| E (alternate) | Electro-Deposited (ED) copper foil type |
| D (alternate) | Double-treated Rolled-Annealed copper |
The “R” at the end of the product code designates rolled-annealed copper (as in AP9111R), while “E” designates electro-deposited copper (as in AP9111E), and “D” designates double-treated rolled-annealed copper. The distinction between those foil types is one of the most practically important choices in flex circuit material selection, which we’ll break down in detail below.
DuPont Pyralux AP9111R Complete Technical Specifications
Pyralux AP flexible circuit material is a double-sided, copper-clad laminate and an all-polyimide composite of polyimide film bonded to copper foil. This material system is ideal for multilayer flex and rigid-flex applications which require advanced material performance, temperature resistance, and high reliability.
Here are the specific construction parameters and measured properties for the AP9111R configuration:
Construction Parameters
| Parameter | AP9111R Value |
| Dielectric Material | All-polyimide (Kapton-based), adhesiveless |
| Dielectric Thickness | 1.0 mil (25 µm) |
| Copper Type | Rolled-Annealed (RA) |
| Copper Thickness | 35 µm (1.0 oz/ft²) |
| Construction | Double-sided |
| Standard Sheet Sizes | 24×36 in, 24×18 in, 12×18 in |
| Special Sizes | Up to 85 inches in length by request |
Electrical Properties
| Property | Typical Value | Test Method |
| Dielectric Constant (Dk) @ 1 MHz | 3.4 | IPC-TM-650 2.5.5.3 |
| Dielectric Constant (Dk) @ 10 GHz | 3.2 | ASTM D2520 |
| Loss Tangent (Df) @ 1 MHz | 0.002 | IPC-TM-650 2.5.5.3 |
| Loss Tangent (Df) @ 10 GHz | 0.003 | ASTM D2520 |
| Volume Resistivity | >10¹⁷ Ω·cm | IPC-TM-650 2.5.17 |
| Surface Resistance | >10¹⁶ Ω | IPC-TM-650 2.5.17 |
| Dielectric Strength | 200 V/µm | ASTM D149 |
| Moisture & Insulation Resistance | >10¹¹ Ω | IPC-TM-650 2.6.3.2 |
Thermal & Mechanical Properties
| Property | Typical Value | Test Method |
| Glass Transition Temperature (Tg) | 220°C | DuPont Method, TMA |
| Solder Float (288°C, 10 s) | Pass | IPC-TM-650 2.4.13 |
| CTE (XY-axis, below Tg) | ~25 ppm/°C | IPC-TM-650 2.4.41 |
| CTE (XY-axis, above Tg) | ~30 ppm/°C | IPC-TM-650 2.4.41 |
| Tensile Strength | 345 MPa | IPC-TM-650 2.4.19 |
| Tensile Modulus | 4.8 GPa | IPC-TM-650 2.4.19 |
| Elongation at Break | 50% | IPC-TM-650 2.4.19 |
| Peel Strength (as received) | >1.8 N/mm (10 lb/in) | IPC-TM-650 2.4.9 |
| Peel Strength (after solder) | >1.8 N/mm (10 lb/in) | IPC-TM-650 2.4.9 |
| Moisture Absorption | 0.8% | IPC-TM-650 2.6.2 |
| Flexural Endurance | 6,000+ cycles | IPC-TM-650 2.4.3 |
Dimensional Stability
| Condition | Stability (MD/TD) | Test Method |
| After etching | ±0.04 to ±0.08% | IPC-TM-650 2.2.4 |
| After thermal (200°C, 30 min) | ±0.04 to ±0.07% | IPC-TM-650 2.2.4 |
Certifications and Compliance
| Standard / Rating | Status |
| IPC-4204/11 | Certified |
| UL 94 V-0 | Listed (File E124294) |
| UL 796 Max Operating Temp. | 200°C |
| ISO 9001:2015 | Manufacturing facility certified |
| RoHS Compliant | Yes |
| Halogen-Free | Yes |
| NASA Outgassing | Data available |
Why RA Copper Makes AP9111R the Right Call for Dynamic Flex
This is the spec decision that often trips up engineers who are newer to flex circuit materials. Both rolled-annealed and electro-deposited copper foils are available across the Pyralux AP line, and they’re not interchangeable when your circuit needs to flex repeatedly.
For flex zones requiring dynamic bending, rolled-annealed (RA) copper is the correct choice — it provides the grain structure needed to sustain 100,000 or more bend cycles without fatigue cracking. ED copper, by contrast, has a columnar grain structure created by electrochemical deposition. That structure doesn’t tolerate repeated strain the way RA copper’s longitudinally aligned grain does.
Here’s how the two foil types compare when you’re making a flex circuit material selection:
| Characteristic | RA Copper (AP9111R) | ED Copper (AP9111E) |
| Grain Structure | Longitudinally aligned, work-hardened | Columnar, electrodeposited |
| Dynamic Flex Life | Excellent (>100,000 cycles) | Limited — static/semi-dynamic only |
| Surface Roughness | Smooth (shiny side) | Higher roughness (matte) |
| Fine Line Etching | Good | Slightly better uniformity |
| Cost | Higher | Lower |
| Best Application | Dynamic flex, repeated bending | Static flex, rigid-flex inner layers |
For AP9111R specifically, the 1 oz (35 µm) copper weight is worth examining in the context of flex design. Heavier copper means more stiffness in the flex zone. The minimum bend radius formula scales with total flex zone thickness: R = t × K, where K is a layer-dependent coefficient — for a single-layer dynamic flex zone, K runs from 6 to 10. With 35 µm copper on both sides of a 25 µm polyimide, your total stack is roughly 95 µm (about 3.7 mils), so your minimum dynamic bend radius starts around 0.6–0.9 mm for a single-layer construction. Multi-layer designs multiply that quickly.
If your trace widths and current requirements allow, dropping to 0.5 oz copper (AP8515R) gains you significantly tighter bend radius capability. But where you genuinely need the current capacity of 1 oz copper in a dynamic flex region — power rails in wearables, for instance — AP9111R is what you use.
The Adhesiveless Advantage: Why No Adhesive Layer Matters for 1 oz Flex
Adhesive-based flex laminates (Pyralux LF and FR being the common examples) sandwich an acrylic or epoxy adhesive layer between the copper and polyimide. That adhesive layer typically runs 1–2 mils thick and has a significantly lower Tg than polyimide — usually in the 150–170°C range. For heavy copper flex circuits running at elevated temperatures, that lower-Tg adhesive layer is often the first thing to fail.
Pyralux AP adhesiveless laminate was developed for high-reliability flexible and rigid circuit applications requiring thin dielectric profiles and the superior performance provided by its all-polyimide construction. All-polyimide constructions enable designers, fabricators, and assemblers to achieve higher density, premium performance circuitry. The high material modulus provides excellent handling characteristics in a thin adhesiveless laminate.
With AP9111R, the polyimide dielectric bonds directly to the 1 oz RA copper without any adhesive intermediate. In practical terms for a PCB engineer, that means:
The thermal ceiling is the polyimide’s Tg (220°C), not an adhesive’s. Heavy copper flex circuits running in under-hood automotive environments or adjacent to heat-generating components get meaningful margin from this.
The total stack is thinner. 1 oz copper on adhesive-based construction adds at least 1–1.5 mils of adhesive on each face. In a multilayer flex where you’re running 4–6 copper layers, that extra thickness pushes your flex zone past viable bend radius limits. AP9111R keeps the dielectric contribution to 1.0 mil.
Chemical resistance is better. The polyimide dielectric withstands the oxide treatment and desmear chemistry in multilayer lamination without the adhesive undercutting or blistering issues that can occur with acrylic adhesive laminates.
DuPont Pyralux AP9111R in Real PCB Applications
Pyralux AP is widely used in automotive electronics, medical devices, aerospace systems, and 5G communication equipment, but let’s look at where the specific 1 oz RA copper / 1 mil PI configuration of AP9111R earns its place versus lighter copper variants.
Power Distribution in Flex and Rigid-Flex Assemblies
The 35 µm (1 oz) copper weight in AP9111R gives it a current-carrying advantage over 0.5 oz configurations. For power rails, ground return paths, and any trace carrying more than a few hundred milliamps through a flex zone, 1 oz copper is often the minimum you can specify without trace width becoming impractical. This makes AP9111R the go-to for rigid-flex assemblies where the flex zone must carry both signal and moderate power simultaneously.
Aerospace and Defense Systems
Defense and aerospace electronics — including satellite systems and avionics — are among the primary application areas for Pyralux AP. At this performance tier, IPC-4204/11 certification and DuPont’s lot-level traceability under ISO 9001:2015 are non-negotiable requirements. The low NASA-documented outgassing of AP9111R meets the vacuum environment requirements of satellite-class hardware, while the 220°C Tg covers the temperature extremes seen in avionics platforms. For DuPont PCB manufacturers serving aerospace supply chains, AP9111R is a standard material specification.
High-Reliability Industrial and Robotic Flex Cables
Factory automation, robotic joints, and cable track systems all subject flex circuits to demanding dynamic bend cycles. AP9111R’s RA copper foil, rated for 6,000+ flex cycles at IPC-TM-650 2.4.3 test conditions, provides the fatigue life that ED copper simply cannot match in these environments. Combined with the polyimide’s resistance to industrial solvents, cutting fluids, and cleaning agents, it’s a sensible material selection for harsh factory floor applications.
Medical Electronics
Medical diagnostic equipment including imaging systems and wearables represents a growing application space for AP9111R. The 1 oz copper handles the power routing requirements of imaging sensor arrays, while the dimensional stability — within ±0.08% after etching — supports the precision registration needed for fine-pitch component assembly. The material is compatible with standard sterilization processes for non-implantable instrumentation.
AP9111R in the Pyralux AP Product Family: Selecting the Right Configuration
AP9111R sits at a specific intersection of copper weight and dielectric thickness within the broader Pyralux AP family. Here’s how it compares to adjacent configurations:
| Product Code | Dielectric (mil) | Copper (µm / oz) | Foil Type | Best Use Case |
| AP8515R | 1.0 | 18 / 0.5 | RA | Lightweight flex, tight bend radius |
| AP9111R | 1.0 | 35 / 1.0 | RA | 1 oz dynamic flex, power routing |
| AP9121R | 2.0 | 35 / 1.0 | RA | Standard 1 oz rigid-flex core |
| AP9131R | 3.0 | 35 / 1.0 | RA | Thick-core controlled impedance |
| AP9111E | 1.0 | 35 / 1.0 | ED | 1 oz static flex, cost-sensitive |
| AP9222R | 2.0 | 70 / 2.0 | RA | 2 oz heavy copper power circuits |
When you need 1 oz RA copper on a 1 mil dielectric — the thinnest adhesiveless configuration in that copper weight — AP9111R is the specific product code. If your design can tolerate a 2 mil dielectric, AP9121R offers more impedance design flexibility for the same copper weight.
Processing and Fabrication Notes for AP9111R
AP9111R processes identically to the rest of the Pyralux AP double-sided clad family, which means standard flexible circuit fabrication equipment handles it without modification.
Pyralux AP Double-side Clad is fully compatible with all conventional flexible circuit fabrication processes, including oxide treatment and wet chemical plated-through-hole desmearing. Fabricated circuits can be cover coated and laminated together to form multilayers or bonded to heat sinks using polyimide, acrylic, or epoxy adhesives.
A few practical notes specifically relevant to the 1 oz copper weight:
Etching: At 35 µm copper, etch factor control matters more than with 0.5 oz foil. Undercut is proportionally larger relative to your trace pitch. If you’re running fine-line traces alongside heavy power conductors on the same panel, your etch compensation needs to account for the full copper thickness.
Drilling: The standard recommendation applies — sharp carbide tooling, vacuum extraction, adequate chip load. Polyimide generates stringy debris that can pack drill flutes faster than glass-reinforced substrates, so tool monitoring is important.
Coverlay selection: Coverlay thickness should be matched to copper weight — for 1 oz copper, a 1.5 mil coverlay is the appropriate starting specification.
Storage: AP9111R should be stored in its original packaging at 4–29°C (40–85°F) and below 70% relative humidity. The product should not be refrigerated or frozen and must be kept dry, clean, and well protected. No cold storage is needed, which simplifies warehouse management compared to moisture-sensitive specialty laminates.
Useful Resources for Engineers and Fabricators
- DuPont Official Pyralux AP Product Page: pyralux.dupont.com — product selector, datasheets, processing guides
- Official Technical Data Sheet (PDF): Search “Pyralux AP double-sided copper-clad laminate datasheet” at DuPont’s resource center or via authorized distributors
- IPC-4204A Standard — “Flexible Metal-Clad Dielectrics for Use in Fabrication of Flexible Printed Circuits”: ipc.org
- IPC-2223 — “Sectional Design Standard for Flexible Printed Boards” (bend radius formulas, layer count rules): ipc.org
- IPC-TM-650 Test Methods — all referenced test procedures, free access: ipc.org/test-methods
- IPC-6013 — Qualification and Performance Specification for Flexible Printed Boards: ipc.org
- NASA Outgassing Database — Pyralux AP outgassing data: outgassing.nasa.gov
- UL Product iQ — UL listing verification for Pyralux AP (File E124294): iq.ul.com
- Insulectro Distributor — Pyralux AP stocking distributor with technical support: insulectro.com
Frequently Asked Questions About DuPont Pyralux AP9111R
Q1: What does the “R” in AP9111R mean, and when should I use “E” instead?
The “R” designates rolled-annealed (RA) copper foil, versus “E” for electro-deposited copper. RA copper has a longitudinally aligned grain structure that gives it dramatically better fatigue resistance under repeated bending — the correct choice for any application with thousands or millions of flex cycles. The “E” variant (AP9111E) uses ED copper, which has better etch uniformity and costs slightly less, but is only appropriate for static or semi-dynamic flex applications where bend cycling is minimal.
Q2: Can AP9111R be used as an outer layer in a rigid-flex multilayer stack?
Yes — this is one of the most common uses. In a rigid-flex multilayer where the flex zone needs to carry power at 1 oz weight, AP9111R serves as the flex core or flex outer layer. Its 1 mil dielectric allows the flex zone to stay thin even with multiple conductor layers, which keeps the minimum bend radius manageable. The direct bond between RA copper and polyimide (no adhesive) also survives the press-lamination cycles in multilayer fabrication without delamination risk.
Q3: What’s the difference between AP9111R and AP9121R, and how do I choose?
Both use 35 µm (1 oz) RA copper. The difference is the polyimide dielectric thickness: AP9111R has 1.0 mil and AP9121R has 2.0 mil. If you need the thinnest possible flex zone for tight bend radius requirements, AP9111R wins. If you’re designing a controlled-impedance circuit where a thicker dielectric gives you more practical trace widths for your target impedance (50Ω microstrip or stripline), AP9121R is often the better starting point. DuPont’s own data shows that a thicker core in a 50Ω microstrip design allows wider traces, which translates to better fabrication yield.
Q4: Is AP9111R compatible with lead-free soldering and ENIG surface finish?
Yes to both. The 288°C solder float pass at 10 seconds confirms AP9111R handles lead-free reflow peak temperatures (typically 250–260°C) comfortably, with margin to spare against the material’s 220°C Tg. ENIG (Electroless Nickel Immersion Gold) is fully compatible with the AP9111R copper, and it’s the most common surface finish specified for fine-pitch component assembly on this material class. ENEPIG is also used where gold wire bonding is part of the assembly.
Q5: How does DuPont Pyralux AP9111R compare to competing adhesiveless flex laminates from Taiflex or Ube?
AP9111R is part of the Pyralux AP family, which carries over 30 years of documented reliability data across aerospace, defense, and medical programs — the database behind it is unmatched. Competing materials from Taiflex (FCCL series) and Ube Industries (UPISEL-N) offer comparable Dk and Df values and are competitively priced for commercial applications. The practical differences come down to certification traceability, datasheet depth, and supply chain stability. For IPC Class 3 / AS9100-qualified production lines where material heritage documentation is audited, most engineers default to Pyralux AP without extensive qualification testing. For cost-sensitive consumer electronics where Class 2 performance is acceptable, alternatives deserve evaluation.
Technical data referenced throughout this article is drawn from DuPont’s published Pyralux AP technical data sheets. Always obtain the current datasheet directly from DuPont before finalizing production specifications, as material properties may be updated over time.
