PCB materials play a crucial role in ensuring the overall reliability and performance of electronic products. With numerous options available, it becomes essential to explore high-quality materials that meet the demanding requirements of modern electronics.
In this article, we will focus on Arlon‘s exceptional offering: the Arlon 49N PCB material. Developed and manufactured by Arlon, a renowned industry leader in the production of prepreg materials, copper clad laminates, and bonding solutions, the Arlon 49N PCB material stands out for its ability to fabricate frequency-dependent and high-performance printed circuit boards. Join us as we delve into the features, general properties, applications, and benefits of utilizing the Arlon 49N PCB material, expanding your knowledge in this realm.
What is the Arlon 49N PCB Material?
The Arlon 49N PCB material is a type of epoxy prepreg specifically engineered for use in printed circuit boards (PCBs). It is designed to provide excellent bonding capabilities for multilayer epoxy rigid-flex structures or for attaching heat sinks to multilayer epoxy PCBs.
The key feature of the Arlon 49N material is its high glass transition temperature of 170⁰C, which enables its application in high-performance or high-temperature scenarios that surpass the capabilities of standard difunctional epoxy low-flow materials. This makes the Arlon 49N PCB material well-suited for demanding applications where elevated temperatures or superior performance are required.
Additionally, it is particularly suitable for high layer count rigid-flex applications where concerns regarding z-axis expansion need to be addressed. The Arlon 49N material complies with the requirements laid out in the IPC-4101/26 standard, ensuring its reliability and quality in PCB manufacturing.
The Arlon 49N PCB material exhibits several key features that make it a highly desirable choice for PCB applications:
1.Enhanced High-Temperature and PTH Reliability:
The 49N material is formulated with a multifunctional epoxy resin system that offers a high glass transition temperature (Tg) of 170°C. This elevated Tg ensures improved performance and reliability under high-temperature conditions, making it suitable for demanding applications.
The material is engineered using discrete low ranges and various fiberglass styles, allowing for optimized flexibility. This characteristic enables the material to adapt to the specific requirements of different PCB designs, enhancing its versatility.
3.Meets IPC-4101/26 Requirements:
The 49N material is designed to comply with the electrical and mechanical properties specified in the IPC-4101/26 standard. These properties have been modified to meet the specific needs of a “Low-Flow” application, ensuring that the material performs as intended.
The Arlon 49N PCB material is manufactured in compliance with the Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) directives. This compliance ensures that the material is free from hazardous substances and contributes to environmentally friendly PCB manufacturing.
Overall, the Arlon 49N PCB material offers improved high-temperature and plated-through-hole (PTH) reliability, flexible design options, adherence to IPC-4101/26 requirements, and compliance with RoHS/WEEE regulations, making it a reliable and environmentally conscious choice for various PCB applications.
Properties of the Arlon 49N PCB Material
The Arlon 49N PCB material possesses the following physical, electrical, mechanical, and thermal properties:
1. Physical Properties:
●Density: Approximately 1.65 g/cm3
●Flammability Rating: V0 (UL 94)
●Thermal Conductivity: 0.25 W/mK
●Water Absorption: 0.1%
2. Electrical Properties:
●Dielectric Constant (at 1 MHz): 4.3
●Dissipation Factor (at 1 MHz): 0.022
●Volume Resistivity (C96/35/90): 5.1 × 107 MΩ-cm
●Volume Resistivity (E24/125): 7.4 × 107 MΩ-cm
●Surface Resistivity (E24/125): 1.5 × 106 MΩ
●Surface Resistivity (C96/35/90): 8.8 × 106 MΩ
●Electrical Strength: 39.4 kV/mm
3. Mechanical Properties:
●Poisson’s Ratio: 0.17
●Young’s Modulus (CD/MD): 2.6 Mpsi
●Tensile Strength: 45 MPa
4. Thermal Properties:
●Glass Transition Temperature (DSC): 170 degrees Celsius
●Decomposition Temperature: 296 degrees Celsius (initial)
●Coefficient of Thermal Expansion (CTE) (X, Y axis): 16 ppm/°C
●Weight Loss at 325 degrees Celsius: 5% (of initial weight)
●Time to Reach T260: Approximately 18 minutes
These properties provide essential information about the material’s behavior and performance in various conditions. They help in understanding the material’s suitability for specific applications, such as its electrical insulation properties, thermal stability, mechanical strength, and compatibility with various manufacturing processes in the PCB industry.
Typical Applications of Arlon 49N PCB Substrate
The Arlon 49N PCB material finds typical applications in the following scenarios:
1. Bonding Multilayer Epoxy Rigid-Flex: The 49N material is well-suited for bonding multilayer epoxy rigid-flex structures. It provides reliable adhesion between the layers, ensuring the structural integrity and functionality of the rigid-flex PCB.
2. Bonding Adhesiveless Epoxy Rigid-Flex: In addition to multilayer epoxy rigid-flex, the 49N material can also be used for bonding adhesiveless epoxy rigid-flex structures. This application benefits from the material’s excellent bonding capabilities, ensuring secure and durable connections between the layers of the rigid-flex PCB.
3. Attaching Heat Sinks to Polyimide MLBs: The 49N material is suitable for attaching heat sinks to polyimide (MLBs) or metal-backed layers. Heat sinks are commonly used to dissipate heat from electronic components, and the 49N material enables reliable bonding of the heat sinks to the PCB, ensuring efficient heat transfer and thermal management.
These typical applications highlight the versatility of the Arlon 49N PCB material in various PCB designs, including rigid-flex structures and applications where heat management is crucial. Its bonding capabilities and compatibility with different materials make it a reliable choice for ensuring the performance and reliability of electronic assemblies.
Arlon 49N: Recommended Process Conditions
To process the inner layers of PCBs using standard industry practices, the following steps should be followed:
1. Develop: The inner layers are coated with a photosensitive material, such as photoresist, and exposed to UV light through a photomask. This process defines the circuit pattern on the inner layers.
2. Etch: After the development step, the exposed areas of the inner layers are etched away using a chemical solution. This removes the unwanted copper, leaving behind the desired circuit traces.
3. Strip: The remaining photoresist is stripped off from the inner layers using appropriate stripping agents. This step ensures that the inner layers are clean and ready for further processing.
Before proceeding with the subsequent steps, it is recommended to perform the following preparations:
4. Bake Inner Layers: The inner layers should be baked in a rack for 60 minutes at a temperature range of 225°F – 250°F (107°C – 121°C). This baking process helps remove any moisture and ensures the inner layers are dry and ready for lamination.
5. Vacuum Desiccate Prepreg: The prepreg material should be vacuum desiccated for 8 – 12 hours prior to lamination. This process removes any moisture from the prepreg, ensuring its stability and preventing issues like delamination during lamination.
By following these steps and adhering to the specified temperature and time ranges, the inner layers of the PCB can be effectively processed using industry-standard practices. These steps help ensure the quality and reliability of the PCB during subsequent lamination and assembly processes.
Arlon 49N PCB Laminate: Lamination Cycle
The lamination cycle for the Arlon 49N PCB material can be carried out as follows:
1. Pre-vacuum: Prior to lamination, pre-vacuum the materials for a duration of 30 to 45 minutes. This step helps remove any trapped air and ensures optimal bonding during the lamination process.
2. Controlled Heat Rise: Control the heat rise during lamination to approximately 8°F – 12°F per minute (4.5°C – 6.5°C) within the temperature range of 210°F to 300°F (100°C to 150°C). This gradual increase in temperature helps prevent any thermal stress or delamination issues.
3. Lamination Pressure: Apply a lamination pressure between 150-300 PSI (11-21 Kg/cm2), depending on the complexity of the PCB design. The appropriate pressure ensures proper bonding of the layers.
4. Cure Temperature: Start the curing process at a product temperature of 360°F (182°C). Maintain this temperature for a duration of 90 minutes. The curing process ensures the material achieves its desired properties and dimensional stability.
5. Cool Down: After the curing process, cool down the laminated PCB under pressure at a rate of ≤10°F/min (6°C/min). This controlled cooling helps prevent warpage and ensures the stability of the PCB.
Additional considerations for post-lamination processes:
●Drilling: When drilling vias with a diameter of 0.023″ (0.9cm) or smaller, it is recommended to use undercut bits. The drilling speed should be set between 350-400 SFM (Surface Feet per Minute).
●De-smear: To remove resin smear from the drilled holes, de-smear using either alkaline permanganate or plasma treatment. The plasma method is preferred, using appropriate settings for epoxy de-smearing.
●Plating: The Arlon 49N material is compatible with conventional plating processes.
●Profiling: Standard profiling parameters can be used for shaping the PCB. However, it is not recommended to use chip breaker style router bits.
●Bake: Prior to solder reflow or HASL (Hot Air Solder Leveling), bake the PCB for 1-2 hours at 250°F (121°C). This step helps ensure optimal performance during subsequent soldering processes.
By following this lamination cycle and the recommended post-lamination processes, the Arlon 49N PCB material can be successfully processed and prepared for further assembly and soldering operations.
Arlon 49N PCB materials have revolutionized the field of advanced electronics with their exceptional properties and versatility. From their high thermal conductivity to their excellent electrical insulation capabilities, these materials empower engineers to push the boundaries of technology.
As the demand for more compact, high-performance electronic devices continues to rise, Arlon 49N PCB materials are poised to play a critical role in shaping the future of the industry. With their ability to withstand demanding conditions and deliver consistent performance, Arlon 49N materials are unlocking new possibilities for innovation, ensuring a brighter and more connected world.