DuPont Pyralux AC091200 specs, construction details, and flex PCB applications — complete technical guide covering 1 oz RA copper, 1 mil acrylic adhesive, 1 mil Kapton PI, key electrical properties, processing tips, and FAQs from a PCB engineer’s perspective.

If you’ve spent any time sourcing materials for single-sided flexible circuits, you’ve probably run into the DuPont Pyralux AC091200. It’s one of those workhorses in the flex laminate world that doesn’t get as much press as the adhesiveless AP series, but for a huge range of cost-sensitive and mid-performance applications, it hits a sweet spot that’s hard to beat. This guide breaks down everything you need to know — construction, specs, processing considerations, and where it actually makes sense to use it.

What Is DuPont Pyralux AC091200?

DuPont Pyralux AC091200 is a single-sided, copper-clad flexible laminate from DuPont’s Pyralux AC product family. The “AC” in the product line name stands for the acrylic adhesive construction — distinguishing it from the adhesiveless AP series. The specific build for AC091200 is:

• 1 oz Rolled-Annealed (RA) Copper
• 1 mil (25 µm) Acrylic Adhesive
• 1 mil (25 µm) DuPont™ Kapton® Polyimide Film

That three-layer sandwich — copper on top, acrylic adhesive as the bond layer, and Kapton PI as the dielectric — is the defining feature of the classic Pyralux AC construction. The total dielectric package (adhesive + PI) sits at 2 mils, which is worth keeping in mind when you’re calculating total laminate thickness for your stack-up.

The choice of Rolled-Annealed (RA) copper is deliberate and important. Compared to Electro-Deposited (ED) copper, RA copper has a grain structure that runs parallel to the foil surface, which translates directly to superior flex endurance. If your design involves dynamic flexing, tight bend radii, or repeated cycling, RA copper is the right call.

DuPont Pyralux AC091200 Full Technical Specifications

The table below consolidates the key material properties for the Pyralux AC single-sided series. Data for AC091200 is consistent with the AC family and verified against DuPont’s published technical data sheet (EI-10122):

Property	Value	Test Method
Copper Type	Rolled-Annealed (RA)	—
Copper Thickness	35 µm (1.0 oz/ft²)	—
Adhesive Type	Acrylic	—
Adhesive Thickness	25 µm (1.0 mil)	—
Polyimide Thickness	25 µm (1.0 mil)	—
Dielectric Constant (Dk) @ 1 MHz	3.7	IPC-TM-650 2.5.5.3
Loss Tangent (Df) @ 1 MHz	0.003	IPC-TM-650 2.5.5.3
Peel Strength (As Received)	≥ 0.6 N/mm (3.4 lb/in)	IPC-TM-650 2.4.9
Peel Strength (After Solder)	≥ 0.6 N/mm (3.4 lb/in)	IPC-TM-650 2.4.9
Dimensional Stability	±0.05%	IPC-TM-650 2.2.4
CTE (XY Axis)	19 ppm/°C	IPC-TM-650 2.4.41
Glass Transition Temp (Tg)	~150°C (acrylic adhesive)	—
Solder Float (288°C / 10 sec)	Pass	IPC-TM-650 2.4.13
Moisture Absorption	0.9%	IPC-TM-650 2.6.2
Volume Resistivity	> 10¹⁶ Ω·cm	IPC-TM-650 2.5.17
Surface Resistance	> 10¹² Ω	IPC-TM-650 2.5.17
Tensile Strength	> 190 MPa	IPC-TM-650 2.4.19
Elongation	> 19%	IPC-TM-650 2.4.19
Flexural Endurance	> 1,600 cycles	JIS C6471 (MIT)
IPC Certification	IPC-4204/25	—
UL Rating	UL 94V-0, File E161336	—
RoHS Compliance	Yes	—

One number worth flagging: the Tg of the acrylic adhesive layer is approximately 150°C. The Kapton PI film itself handles well past 280°C, but the acrylic adhesive is your thermal ceiling in practice. Keep that in mind for any reflow or wave solder considerations.

Pyralux AC Product Code Decoder

DuPont’s Pyralux AC part number system is logical once you understand the pattern. The AC091200 code breaks down as follows:

Code Segment	Meaning	AC091200 Value
AC	Product family (Acrylic construction)	AC
09	Copper thickness code	1 oz (35 µm) RA
12	Polyimide dielectric thickness	1 mil (25 µm) PI
00	Adhesive/grade designator	1 mil acrylic (standard)

For comparison, here’s how AC091200 sits within the broader Pyralux AC single-sided offering:

Product Code	Copper	Type	Dielectric
AC091200	1 oz	RA	1 mil PI + 1 mil adhesive
AC121200RY	0.33 oz	RA	0.5 mil PI
AC181200RY	0.5 oz	RA	0.5 mil PI
AC182500RY	0.5 oz	RA	1.0 mil PI
AC351200RHV	1 oz	RA	0.5 mil PI
AC352500RHV	1 oz	RA	1.0 mil PI

Understanding this matrix helps you quickly select an alternative if your design needs a different copper weight or dielectric thickness while staying in the same acrylic-adhesive construction family.

AC091200 vs. Pyralux AP: Adhesiveless vs. Adhesive Construction

This is the question that comes up constantly in design reviews, so let’s address it head-on.

Why Choose Pyralux AC (Adhesive Construction)?

The acrylic adhesive in AC091200 acts as the mechanical bond between the Kapton PI film and the copper foil. This manufacturing approach has been in the industry for decades and is extremely well-characterized. The advantages are straightforward: lower cost, a wider availability from contract flex manufacturers, and full compatibility with conventional flex circuit fabrication processes including oxide treatment and wet chemical PTH desmearing.

Why Choose Pyralux AP (Adhesiveless)?

The adhesiveless AP series eliminates the acrylic layer entirely by directly bonding copper to polyimide through a casting or lamination process. The result is a higher thermal ceiling (no adhesive Tg limitation), better dimensional stability, and thinner overall construction. It also supports finer lines and spaces more reliably because you’re not contending with adhesive flow during lamination.

The Bottom Line

For high-reliability, high-temperature, or military/aerospace programs, the AP series is usually the right answer. For single-sided consumer electronics, wearables, handheld devices, and cost-sensitive production programs, AC091200 is a proven and practical choice. Many DuPont PCB fabrication programs use the AC series as their standard single-sided flex laminate.

Processing DuPont Pyralux AC091200

The Pyralux AC series is designed to be fully compatible with standard flex circuit fabrication — no exotic processing equipment required. Here are the points that matter most on the shop floor.

Etching

The 1 oz RA copper etches cleanly and predictably. RA foil has tighter grain structure than ED copper, which means slightly better etch uniformity and edge definition — a benefit when you’re pushing fine pitch lines.

Coverlay Lamination

For most single-sided flex circuits using AC091200, you’ll be applying a polyimide coverlay over the etched copper. The acrylic adhesive in the AC laminate is compatible with standard acrylic-based coverlays (such as Pyralux FR or LF series). Lamination parameters should follow the coverlay manufacturer’s recommendations, typically involving heat and pressure in a hydraulic press or vacuum laminator.

Solder Compatibility

The material passes the solder float test at 288°C for 10 seconds, which means it handles standard lead-free reflow profiles without delamination, assuming you stay within the acrylic adhesive’s thermal limits. If your assembly process consistently exceeds 150°C for extended dwell times, consider bumping up to an AP series laminate.

Storage

Store AC091200 in original packaging at temperatures of 4–29°C (40–85°F) and below 70% relative humidity. Avoid freezing the material and keep it dry and protected. Out-of-condition storage can affect adhesive properties and copper surface oxidation, both of which will cause you headaches in lamination.

Key Applications for DuPont Pyralux AC091200

The single-sided construction and acrylic adhesive system position AC091200 well for a range of real-world applications.

Consumer Electronics & Wearables

Smartphones, fitness trackers, and hearables rely heavily on single-sided flex circuits to route signals through tight mechanical envelopes. The 1 oz RA copper handles the flex cycling well, and the 1 mil Kapton dielectric keeps the overall thickness low enough for thin product profiles.

Medical Devices (Non-Implantable)

Portable diagnostic devices, patient monitors, and wearable health sensors are natural fits. The RoHS-compliant construction and UL 94V-0 rating satisfy most non-implantable medical device requirements. Note that DuPont specifically cautions against use in applications involving permanent implantation in the human body.

Automotive Sensors and Instrumentation

For sensors and connectors that need to survive under-hood vibration and moderate thermal cycling, AC091200’s dimensional stability (±0.05%) and solid peel strength provide reliable performance. The acrylic adhesive Tg of ~150°C is sufficient for most sensor packaging environments away from direct heat sources.

Industrial Controls and Robotics

Flex circuits in robotic joints, industrial cameras, and servo drives benefit from the high flexural endurance (>1,600 MIT bend cycles) and the mechanical resilience of RA copper foil.

Display Interconnects

Flat panel displays and OLED modules commonly use single-sided flex circuits for driver connections. The combination of 1 oz copper and 1 mil PI offers a good impedance profile for moderate-frequency signal routing.

Useful Resources for DuPont Pyralux AC091200

The following resources are directly useful if you’re specifying, procuring, or processing AC091200:

• DuPont Pyralux Official Product Page: pyralux.dupont.com — product selector, datasheets, and safe handling guides
• Pyralux AC Technical Data Sheet (EI-10122): Available for download from DuPont Electronics — includes full property tables and product code matrix
• IPC-4204/25 Flexible Metal-Clad Dielectrics Standard: The governing IPC specification for this material class
• IPC-TM-650 Test Methods: Referenced throughout the DuPont datasheet for all reported electrical and mechanical properties
• UL Product iQ Database: Search UL File E161336 to verify current UL 94V-0 status
• DuPont Pyralux Safe Handling Guide: Available at pyralux.dupont.com — essential reading before setting up lamination processes

Frequently Asked Questions

Q1: What is the difference between DuPont Pyralux AC091200 and the AP series?

AC091200 uses an acrylic adhesive layer to bond the copper to the Kapton polyimide film, making it an adhesive-based laminate. The Pyralux AP series is adhesiveless — the copper bonds directly to the polyimide. The AP series offers a higher thermal ceiling and better dimensional stability, but costs more. AC091200 is preferred when cost and standard processing compatibility are priorities.

Q2: Can DuPont Pyralux AC091200 be used for dynamic flex applications?

Yes. The 1 oz Rolled-Annealed (RA) copper is specifically chosen for flex endurance. RA foil’s grain orientation resists work-hardening and cracking under repeated bending, unlike electro-deposited copper. With a rated flexural endurance of >1,600 MIT cycles, AC091200 handles dynamic flex well in appropriately designed circuits.

Q3: What is the maximum continuous operating temperature for AC091200?

The limiting factor is the acrylic adhesive layer, which has a glass transition temperature (Tg) of approximately 150°C. The Kapton polyimide film itself is rated well above 200°C, but the adhesive will be the failure point at elevated temperatures. For sustained high-temperature operation, the adhesiveless Pyralux AP or AP-series laminates are better choices.

Q4: Is DuPont Pyralux AC091200 RoHS compliant?

Yes. The Pyralux AC single-sided copper-clad laminate is RoHS compliant, making it suitable for consumer electronics and other applications subject to EU RoHS regulations.

Q5: What roll sizes is AC091200 available in?

DuPont supplies Pyralux AC single-sided laminate as 100 linear meter (328 ft) rolls in widths of either 250 mm (9.8 in) or 500 mm (19.7 in). Other sizes are available by special order. For prototyping, many distributors offer smaller sheet quantities.

Final Thoughts

DuPont Pyralux AC091200 is a mature, well-understood flexible laminate that earns its place in countless production programs. The combination of 1 oz RA copper, 1 mil acrylic adhesive, and 1 mil Kapton polyimide delivers a balanced profile: predictable electrical performance, good flex endurance, and full compatibility with standard flex circuit processing. It’s not the material for extreme thermal environments or ultra-fine pitch HDI designs — for those you’ll want to look at the AP adhesiveless family — but for single-sided flex circuits across consumer, medical, automotive, and industrial applications, it remains one of the most practical choices in the Pyralux catalog.

If you’re designing a DuPont PCB flex circuit and trying to match a material to your requirements, AC091200 is always worth putting on the short list.

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