DiClad 870 is a woven-glass PTFE laminate with a nominal dielectric constant between DiClad 880 and the higher selectable DiClad 527 range. It is a useful option for low-loss microwave structures when its geometry and reinforced construction suit the design. The distinction from CuClad 233 is structural as well as commercial.
Material system
Woven-glass-reinforced PTFE
Technical properties
| Property | Reported value | Conditions / source |
|---|---|---|
| Process dielectric constant | 2.33 | Typical, 10 GHz, 23°C; IPC-TM-650 2.5.5.5 clamped stripline; direction is not separately recorded here. Source |
| Dissipation factor | 0.0013 | Typical, 10 GHz, 23°C; IPC-TM-650 2.5.5.5; direction is not separately recorded here. Source |
| Thermal conductivity | 0.26 W/(m·K) | Typical; ASTM E1461, through-thickness direction; test temperature not specified in the product table. Source |
Typical reported values are not a purchase specification. Process Dk, design Dk and values measured at different frequencies are not interchangeable.
Selection and design notes
- Compare it with DiClad 880 when adjusting radiator size or feedline width. Use the actual thickness and a consistent dielectric test basis so that a geometry change is attributable to the material rather than mismatched assumptions.
- When comparing it with a cross-plied CuClad construction, examine directional mechanical and registration behavior alongside RF values. Equal nominal Dk does not make the reinforcement architectures identical.
Thickness and copper options
Check the current DiClad 870 thickness and tolerance table and retain those dimensions in the impedance model.
Specify ED copper or any approved alternative explicitly; copper-side treatment affects conductor loss.
Fabrication considerations
- Keep laminate orientation, copper treatment and PTFE processing requirements in the fabrication package. For phase-critical structures, include a coupon or line pair that reflects the actual routing direction and copper process.
Application fit
- Low-Dk microwave lines
- Printed antennas
- Reinforced PTFE RF boards
Limits and substitution checks
- A low-loss value at 10 GHz does not guarantee total insertion loss across a broadband connectorized assembly. The current datasheet's thermal and moisture methods also should not be combined blindly with older selector conditions. Review source, direction and conditioning before ranking candidates.