Complete engineer’s guide to DuPont Pyralux AC092100: specs, layer stack, applications, processing tips, and FAQs for this 0.5 oz copper single-sided flex laminate.
There’s a reason the DuPont Pyralux AC092100 keeps showing up in BOM reviews for thin flex circuits, display driver assemblies, and chip-on-flex applications. It’s not the flashiest laminate in the Pyralux lineup, but for engineers who need a reliable, lightweight single-sided flex substrate with a well-characterized adhesive system, this construction hits a practical sweet spot. This guide breaks it down from a fabrication and design perspective — what it is, how the stack decodes, where it works, and where it doesn’t.
What Is DuPont Pyralux AC092100?
DuPont Pyralux AC flexible circuit materials are single-sided copper-clad laminates consisting of an all-polyimide composite of polyimide film bonded to copper foil. The AC series is designed for single-sided applications such as display drivers, multilayer digital cameras, rigid-flex camcorder circuits, and designs requiring thin, light, and high-density circuitry along with chip-on-flex attachment.
The AC092100 is a specific construction within that family. Decoding the product designation:
| Code Segment | Meaning |
| AC | All-polyimide single-sided clad family |
| 09 | Base copper thickness identifier (~0.5 oz / 18 µm) |
| 21 | Adhesive layer parameter (2 mil / ~50 µm acrylic adhesive) |
| 00 | Polyimide film (1 mil / 25 µm) |
The result is a three-layer construction: 0.5 oz rolled-annealed copper bonded through a 2 mil acrylic adhesive to a 1 mil Kapton® polyimide film. Understanding that layup is critical before you do anything else with this material.
Decoding the Full Stack: 0.5 oz Cu / 2 mil Adhesive / 1 mil PI
This is a stack a lot of engineers glance past without thinking through carefully. Let’s break each layer and what it means to your design.
0.5 oz Copper (18 µm): Why Light Copper?
Half-ounce copper is the right call for high-density fine-line flex work. At 18 µm nominal thickness, you get:
- Fine-line trace resolution down to 75–100 µm lines/spaces depending on your fab’s process capability
- Lower flexural stress at the laminate interface than 1 oz copper during dynamic flex cycling
- Lighter board mass — critical in wearables, aerospace flex harnesses, and medical devices
The trade-off versus 1 oz copper is current-carrying capacity. Before you commit to 0.5 oz for a power rail, run your trace width calculation for your max current and thermal rise tolerance.
2 mil Acrylic Adhesive: The Binding Layer
The acrylic adhesive layer in the AC092100 construction is what bonds the copper foil to the polyimide base. Pyralux AC products deliver excellent dimensional stability, low moisture absorption, high modulus, excellent thermal resistance, and low CTE — all attributes that stem from the polyimide base chemistry.
However, the adhesive layer is also the thermal and chemical weak point in the stack. Acrylic adhesives have a lower glass transition temperature than the polyimide base film, which means the overall laminate’s maximum operating temperature is governed by the adhesive, not the PI film. Engineers working near the 150°C continuous threshold need to validate this carefully.
1 mil Polyimide: Kapton® as the Foundation
Pyralux AC is a single-sided copper-clad material offered in rolls that meets IPC-4204/25, with the base polyimide cast onto the copper to allow thinner clads than traditional manufacturing processes would permit. The 1 mil (25 µm) polyimide is the stiffest and thinnest PI option in the standard AC lineup — it gives you better dimensional control and higher modulus than 0.5 mil constructions, while keeping the overall stack extremely thin.
Full Technical Specifications
The complete material property profile for Pyralux AC includes: peel strength (as received) of 1.19 N/mm (6–7 lb/in), passing solder float at 288°C (550°F) for 10 seconds, dielectric constant of 3.7 at 1 MHz, dissipation factor of 0.0014 at 1 MHz, dielectric strength of 200 kV/mm, volume resistivity of 10¹⁰ MΩ·cm, moisture absorption of 0.94%, CTE of 19 ppm/°C, tensile strength of 193 MPa (28 kpsi), and UL 94 V-0 flammability rating.
| Property | Value | Test Method |
| Copper Thickness | 18 µm (0.5 oz/ft²) | — |
| Adhesive Thickness | ~50 µm (2 mil) | — |
| Polyimide Thickness | 25 µm (1 mil) | — |
| Peel Strength (as received) | 1.19 N/mm (6–7 lb/in) | IPC-TM-650 2.4.9 |
| Peel Strength (post-solder) | 1.19 N/mm (6–7 lb/in) | IPC-TM-650 2.4.9 |
| Solder Float (288°C, 10 sec) | Pass | IPC-TM-650 2.4.13 |
| Dielectric Constant (1 MHz) | 3.7 | IPC-TM-650 2.5.5.3 |
| Dissipation Factor (1 MHz) | 0.0014 | IPC-TM-650 2.5.5.3 |
| Dielectric Strength | 200 kV/mm | ASTM D-149 |
| CTE | 19 ppm/°C | ASTM D-696-91 |
| Moisture Absorption | 0.94% | IPC-TM-650 2.6.2 |
| Tensile Strength | 193 MPa (28 kpsi) | IPC-TM-650 2.4.19 |
| Tensile Modulus | 7,580 MPa (1,100 kpsi) | ASTM D-882 |
| Elongation | 21% | IPC-TM-650 2.4.19 |
| Flammability | UL 94 V-0 | UL-94 |
| Tg (polyimide) | ~220°C | — |
| IPC Specification | IPC-4204/25 | — |
Where DuPont Pyralux AC092100 Gets Used
Pyralux AC flexible circuit materials are well suited to display drivers, multilayer digital cameras, rigid-flex camcorder circuits, chip-on-flex attachment, and any application demanding thin, light, and high-density single-sided circuitry.
Let’s get more specific for each use case:
Display Driver Flex Circuits
Flat panel display assemblies use single-sided flex tails to connect the display glass to the driver PCB. The 1 mil PI keeps the overall stack thin enough to tuck into tight bezel gaps, and the 0.5 oz copper supports the fine pitch traces needed for modern display interfaces. The AC092100 construction is a known performer in this space.
Chip-on-Flex (COF) Substrates
COF assembly requires a flex substrate with excellent dimensional stability — thermal excursion during bonding cannot shift the pad array or the chip fails alignment. The Pyralux AC series demonstrates excellent dimensional stability, with typical values of –0.02% (Method B) and –0.04% (Method C) after thermal processing at 200°C. That level of stability is what COF processes depend on.
Wearable and Medical Flex Circuits
Mass matters in body-worn electronics. The 0.5 oz copper plus 2 mil adhesive plus 1 mil PI stack produces one of the thinner, lighter single-sided flex options in the Pyralux family. Dupont PCB applications in medical patch sensors, hearing aids, and wearable monitors benefit from the combination of low mass, good flexibility, and reliable copper-to-polyimide adhesion.
Rigid-Flex Inner Layer Flex Zones
In rigid-flex multilayer builds, the inner flex layers often use single-sided constructions. The AC092100’s thin profile allows rigid-flex designers to keep the total build-up within envelope while preserving flex zone compliance.
Processing and Fabrication Notes
Standard flexible circuit manufacturing techniques are fully compatible with Pyralux AC processing. Lamination areas should be well ventilated to prevent accumulation of trace solvent vapors from the polyimide that can volatilize during press lamination, and adequate vacuum should be maintained around drill heads during routing to minimize dust exposure.
A few additional engineering points worth noting in practice:
Coverlay vs. Solder Mask
For the 0.5 oz copper in this construction, you have to make a deliberate choice between PI coverlay (laminated) and liquid photo-imageable (LPI) solder mask. LPI is cheaper but can crack at flex zones. On a thin 1 mil PI base, the additional stress from a rigid LPI coating defeats part of the purpose of choosing a thin, flexible laminate. Flex-grade PI coverlay with a compatible adhesive is usually the right call.
Fine Line Etching Considerations
Half-ounce copper etches faster and more uniformly than 1 oz, but the thinner copper is also more vulnerable to over-etch. Work with your fab to establish tight chemistry monitoring on the etch line, especially if you’re running 75 µm traces or tighter.
Pre-preg Surface Treatment
In general, surface treatment of the polyimide surface improves adhesion when bonding with adhesive films. For applications requiring pre-pregs, DuPont recommends specifying Pyralux AC Plus, which is specifically treated for additional bond strength. If you’re building multilayer flex and using AC092100 as an inner layer clad, confirm with your fabricator whether the standard AC surface treatment is sufficient or whether AC Plus is needed for your bondply.
AC092100 vs. Other Pyralux AC Constructions
Choosing the right AC grade comes down to copper weight and PI thickness. Here’s where AC092100 sits relative to common alternatives:
| Product Code | Copper (µm / oz) | Adhesive | Polyimide | Best Use |
| AC092100 | ~18 / 0.5 | 2 mil | 1 mil | Fine line, light flex, COF |
| AC182500R | 18 / 0.5 | None (adhesiveless) | 1 mil | High-temp, adhesiveless single-sided |
| AC182000R | 18 / 0.5 | None | 0.8 mil | Ultra-thin single-sided |
| AC352500R | 35 / 1.0 | None | 1 mil | Higher current single-sided |
| AC092500EV | 9 / 0.25 | None | 1 mil | Ultra-low mass, chip-on-flex |
The adhesive layer in AC092100 adds total thickness but also provides a bonding chemistry familiar to fabs that have been processing acrylic-based Pyralux laminates for decades — which can simplify fabricator qualification if you’re working with a shop that has less experience with adhesiveless processing.
Storage, Shelf Life, and Handling
Pyralux AC laminates carry a two-year warranty from the date of manufacture when stored in original packaging at temperatures of 4–29°C (40–85°F) and below 70% relative humidity. Refrigeration is not required and the material should not be frozen. The material should be kept clean and protected from physical damage.
As with all copper-clad laminates, sharp sheet edges are a cut hazard. Gloves and finger cots should be standard handling practice in the fab area.
Useful Resources
| Resource | Description | Link |
| DuPont Pyralux AC Product Page | Official product overview and ordering | dupont.com/pyralux-ac |
| Pyralux AC Technical Data Sheet (Adafruit mirror) | Full spec table, product code list, properties | cdn-shop.adafruit.com |
| Qnity Pyralux AC Data Sheet (2023) | Updated spec sheet from current DuPont EI spinoff | qnityelectronics.com |
| IPC-4204/25 | IPC specification for Pyralux AC single-sided clad | IPC.org (subscription) |
| Insulectro Pyralux AC Page | Distributor page with availability & ordering | insulectro.com |
| IPC-2223 Sectional Design Standard for Flexible Printed Boards | Design rules for single and multilayer flex | IPC.org |
| DuPont Safe Handling Guide | Pyralux handling and safety instructions | pyralux.dupont.com |
5 FAQs About DuPont Pyralux AC092100
Q1: Is the 2 mil adhesive in AC092100 an acrylic adhesive, and does it affect high-temperature performance?
Yes, the adhesive layer in this construction is an acrylic-based bonding system. Acrylic adhesives typically have a lower Tg and maximum service temperature than the polyimide film itself. While the Kapton® PI base can handle 200°C+ excursions, the adhesive layer limits the practical continuous operating temperature to approximately 105–130°C depending on load conditions. For applications pushing toward 150°C continuous, the adhesiveless AP or AC Plus series is a better fit.
Q2: Can AC092100 be used in dynamic flex applications?
It can, but proceed carefully. The 0.5 oz copper and 1 mil PI are both favorable for flex endurance, and the thin adhesive layer remains reasonably compliant. However, the adhesive interface is the flex fatigue risk — repeated bending can initiate delamination at the copper-adhesive interface over time. Run IPC-TM-650 Method 2.4.3 flexural endurance testing if your application involves more than a few thousand flex cycles.
Q3: What coverlay is compatible with AC092100?
Standard PI-based coverlays using acrylic adhesive — such as Pyralux LF coverlay — are compatible and commonly used. The adhesive chemistry compatibility between the substrate adhesive and the coverlay adhesive is worth verifying with your material supplier, particularly if you’re running unusual cure schedules.
Q4: How does AC092100 handle fine-pitch SMT assembly?
The 0.5 oz copper etches well for fine-pitch pad geometries, and the 1 mil PI with a rigid adhesive layer gives enough dimensional stability for standard SMT reflow. However, because this is a single-sided construction with no stiffener, you’ll need process tooling — vacuum fixtures or FR4 carriers — to support the flex panel during reflow to prevent warpage. That’s standard practice for any thin single-sided flex in SMT.
Q5: What is the IPC specification this material is certified to?
Pyralux AC meets IPC-4204/25, which covers single-sided adhesiveless and adhesive-bonded polyimide flex copper-clad laminates. Manufacturing is conducted under a certified ISO 9001:2015 Quality Management System, with complete material and manufacturing records maintained, including archive samples, and full lot-level traceability through the product packaging label.
Final Thoughts
DuPont Pyralux AC092100 is a straightforward, well-proven laminate for single-sided flex work where you need light copper, thin PI, and a familiar adhesive-based process. It’s not trying to be an adhesiveless all-polyimide high-temperature laminate — and understanding that boundary is the most important design decision you’ll make with it. Spec it into display drivers, COF substrates, and lightweight wearable flex circuits with confidence. Push it into high-temperature or severe dynamic flex environments, and you’ll want to qualify carefully or consider an upgrade to the adhesiveless AC or AP series.
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