TMM® laminates are high-performance, ceramic-filled, thermoset polymer composites designed for microwave and RF applications. Proper routing techniques are essential for creating precise edge profiles and maintaining the laminate’s structural integrity.

Routing Guidelines

1. Router Bit Selection
   • Type: Use carbide or diamond-coated router bits for extended tool life and smooth edges.
   • Geometry:
     • Single-Flute Bits: Ideal for high-speed operations.
     • Double-Flute Bits: Provide better edge finish for intricate designs.
   • Edge Angle: 0°–5° back taper to reduce stress and chipping.
2. Routing Speed and Feed Rate
   • Spindle Speed: 20,000–40,000 RPM, depending on laminate thickness and bit size.
   • Feed Rate: 50–150 inches per minute (IPM). Adjust based on the complexity of the design and panel thickness.
3. Panel Support
   • Use a rigid backer material to prevent flexing or vibration during routing.
   • Clamping the panel securely ensures dimensional accuracy and reduces chipping.
4. Depth of Cut
   • For thick panels, use multiple passes to achieve the desired depth.
   • Recommended depth per pass: 0.02–0.05 inches, depending on the material thickness and bit size.
5. Cooling and Debris Removal
   • Cooling: Apply air cooling to dissipate heat during high-speed routing.
   • Debris Removal: Use vacuum systems to extract ceramic dust and prevent tool clogging.
6. Tool Maintenance
   • Inspect router bits regularly for wear and replace when dull to maintain clean cuts.
   • Re-sharpen carbide bits as necessary to prolong their usability.

Common Routing Challenges and Solutions

Issue	Cause	Solution
Edge Chipping	Excessive feed rate or dull bit	Reduce feed rate; use sharp bits.
Delamination	Incorrect bit geometry	Use tapered bits or backer boards.
Poor Edge Finish	High routing speed or tool wear	Lower speed; replace worn bits.
Dust Accumulation	Inadequate debris extraction	Increase vacuum power.

Routing Tips for High-Quality Results

1. Routing Path:
   • Plan routing paths to minimize stress on narrow sections or intricate patterns.
   • Use gradual curves instead of sharp corners where possible.
2. Panel Orientation:
   • Orient panels so that routing occurs perpendicular to material layers for smoother edges.
3. Tool Wear Management:
   • Use diamond-coated bits for prolonged durability, especially for high-volume production.
4. Surface Protection:
   • Apply protective films on laminate surfaces to prevent scratches during routing.
5. Final Cleaning:
   • After routing, clean panel edges using compressed air or deionized water to remove residual dust.

Additional Notes on TMM® Laminate Routing

• TMM® laminates are abrasive due to their ceramic filler content. Using high-quality tools and maintaining proper speeds are critical for longevity and edge quality.
• Avoid excessive routing force, which can cause cracking or edge distortion.

Adhering to these routing guidelines ensures precise machining of TMM® laminates, preserving their physical properties and ensuring the reliability of high-frequency circuits. For specialized designs or additional support, consult Rogers Corporation’s technical services.