PSR-4000 solder mask Dk and Df
Taiyo PSR-4000 solder mask: Dk 3.9 and Df 0.027 at 1 GHz (Liquid photoimageable solder mask). It is a liquid photoimageable solder mask, so it sets the coating over outer-layer traces, not the dielectric between layers.
Datasheet values
| Entry | Dk | Df | at | Tg | Construction and test method |
|---|---|---|---|---|---|
| PSR-4000 BN DI | 3.9 | 0.027 | 1 GHz | 125 °C | Liquid photoimageable solder mask. |
| PSR-4000 HFX DI | 3.5 | 0.019 | 1 GHz | — | Low-loss solder mask. |
Dk and Df depend on the glass style, the resin content and the test method, so the same product has different values in different constructions. Compare materials at the same frequency and, where possible, with the same method; for a construction not listed here, use the manufacturer’s construction table.
Dk and Df from 1 to 20 GHz
The datasheet gives one frequency. The table extends that point with the Djordjevic–Sarkar wideband Debye model, the same model the impedance and trace-loss calculators use: it keeps Df nearly flat and lets Dk fall slowly with frequency. These are model values, not measurements.
| Entry | 1 GHz | 2 GHz | 5 GHz | 10 GHz | 20 GHz |
|---|---|---|---|---|---|
| PSR-4000 BN DI | 3.90 / 0.027 | 3.85 / 0.027 | 3.79 / 0.027 | 3.75 / 0.027 | 3.70 / 0.026 |
| PSR-4000 HFX DI | 3.50 / 0.019 | 3.47 / 0.019 | 3.43 / 0.019 | 3.40 / 0.019 | 3.37 / 0.018 |
Each cell is Dk / Df.
Solder mask lowers the impedance of an outer-layer trace by a few ohms. The impedance calculator includes the mask thickness and Dk, and the controlled impedance guide shows how much it changes.
Other datasheet pages: Panasonic MEGTRON 6 · Panasonic MEGTRON 4 · Panasonic MEGTRON 7 · Rogers RO4350B · Rogers RO4003C · Rogers RO3003 · Rogers RT/duroid 5880 · Isola 370HR · Isola FR408HR · Isola I-Speed · Isola Tachyon 100G · TUC TU-872 SLK · Shengyi S1141 · Shengyi S1000-2M · Nan Ya NP-155FR · DuPont Pyralux AP · DuPont Pyralux HP
Sources
- Taiyo America PSR-4000 BN DI series TDS (Feb 2024). Solder mask: Dk 3.9, Df 0.027 at 1 GHz.
- Taiyo America PSR-4000 HFX DI TDS (Jun 2020). Solder mask: Dk 3.5, Df 0.019 at 1 GHz.