AD250C 1.524mm High Frequency PCB With Black Solder Mask

Today, we'll discuss AD250C, a commercial microwave and RF laminate material designed with low and tightly controlled dielectric constant.

AD250C laminates are PTFE-based materials reinforced with glass fiber. They offer controlled dielectric constant, low loss performance, and excellent passive intermodulation (PIM) performance. The woven glass reinforcement ensures good circuit processability and enables high yield circuit board fabrication.

Let's dive into the data sheet to explore the properties of AD250C.

AD250C Typical Properties:

PIM: The typical PIM values using reverse treated ED copper foil are -159 dBc at 30 mil thickness and -163 dBc at 60 mil thickness. These values are obtained through extensive PIM testing at Rogers using a two-tone, reflected method on a 50Ω microstrip test vehicle.

Dielectric constant: The process value is 2.52 at 10GHz, with design Dk values at 2.5. This specific value is targeted for antenna applications.

Dissipation factor: At 10GHz, the dissipation factor is 0.0013, indicating very low loss.

TCDk (Thermal Coefficient of Dielectric Constant): AD250C has a TCDk of -117ppm/ºC, which is considered a medium-level number.

Volume resistivity: AD250C exhibits a volume resistivity of 4.8 x 108 Mohm/cm, and the surface resistivity is 4.1 x 107 Mohm, both of which are very good.

Electrical strength: The electrical strength is 979 V/mil in accordance with IPC TM-650 2.5.6.2.

Dielectric breakdown: AD250C has a dielectric breakdown greater than 40 kV.

Moving on to thermal properties:

Decomposition temperature (Td): AD250C exceeds 500ºC, measured under the condition of baking for 2 hours at 105ºC, with a 5% weight loss according to IPC TM-650 2.3.40.

Thermal expansion coefficient: The X and Y axes exhibit a median level of thermal expansion coefficient, while the Z direction shows a slightly poorer value of 196 ppm/ºC.

Thermal conductivity: AD250C has a thermal conductivity of 0.33 W/m/K, which is at a general level.

Let's continue with the mechanical characteristics:

Peel strength: The peel strength of 1oz copper foil after thermal stress is 2.6 N/mm, according to IPC TM-650.

Flexural strength: In the machine direction (MD), the flexural strength is 8.8 MPa, while in the cross-machine direction (CMD), it is 6.4 MPa.

Tensile strength: The tensile strength is 6.0 MPa in MD and 5.6 MPa in CMD.

Flex modulus: In MD, the flex modulus is 885 MPa, and in CMD, it is 778 MPa.

Dimensional stability: AD250C exhibits dimensional stability of 0.02 mils/inch in the machine direction and 0.06 mils/inch in the cross direction.

Now, let's explore the physical characteristics:

Flammability: AD250C complies with the 94V0 standard.

Moisture absorption: AD250C absorbs only 0.04% moisture.

Specific heat capacity: The specific heat capacity is 0.813 J/g K, and the density is 2.28 g/cm3.

PCB options: Bicheng PCB can provide single-sided boards, double-sided boards, multi-layer boards, and hybrid types using AD250C. The standard thicknesses are 20 mils, 30 mils, and 60 mils.

Copper thickness: Finished copper on track lines can be 1oz and 2oz.

Maximum PCB size: The maximum size for AD250C materials is 400mm by 500mm, allowing for single boards or multiple designs on a panel.

Solder mask: Bicheng PCB offers solder mask colors such as green, black, blue, red, and yellow.

Plating possibilities: Various plating options for pads are available, including immersion gold, HASL, immersion silver, immersion tin, OSP, pure gold, ENEPIG, and bare copper.

AD250C PCBs find applications in a variety of industries, including cellular infrastructure for base station antennas, automotive telematics antenna systems, and commercial satellite radio antennas. The excellent PIM performance of AD250C, with PIM values better than -157 dBc, makes it an ideal choice for antenna designers looking to achieve high-quality signal transmission. Its low loss, controlled dielectric constant, and reliable thermal properties make AD250C a reliable choice for high-frequency applications where performance and stability are crucial.