The AGC TLY Family of Low Loss Laminates, specifically the TLY-5Z variant, is designed for applications where low dielectric constant (Dk), low density, and low Z-axis expansion are critical. This makes it particularly suitable for aerospace components, RF passive components, and low-weight antennas for aircraft. The TLY-5Z laminates are advanced glass-filled PTFE composites with woven fiberglass reinforcement, which not only ensures low density but also provides dimensional stability and thermal stability, especially in terms of Z-axis expansion .

For PCB stackup design using TLY-5Z, consider the following guidelines:

• Utilize the low Z-axis coefficient of thermal expansion (CTE) of TLY-5Z to enhance the reliability of plated through holes (PTHs) during thermal cycling.
• Pair TLY-5Z with flat copper or ultra-low profile copper foils to optimize the surface smoothness and improve the adhesion between the laminate and the copper, which is crucial for high-frequency applications where surface irregularities can affect signal integrity .
• Account for the reduced temperature coefficient of dielectric constant (TcK) when designing for frequency stability across temperature variations .

Moreover, TLY-5Z's compatibility with high-volume commercial microwave applications where cost is a concern makes it a viable option over conventional PTFE-rich substrates. Its improved PTH reliability and ability to withstand thermal cycling without the common defects associated with PTFE substrates (like drilling defects and thermal cycle induced cracks) further underscore its utility in complex multilayer stripline designs and Substrate Integrated Waveguide (SIW) applications .

In summary, when designing PCBs with TLY-5Z, focus on leveraging its mechanical and thermal properties to achieve high reliability and performance, especially in applications demanding high precision and stability under thermal stress. This material's properties make it particularly adept for aerospace and advanced RF applications, where consistent performance and structural integrity are paramount.