Isola Group laminates
Isola Laminate & Isola PCB: 370HR, FR408HR, I-Speed, Tachyon, Astra & TerraGreen
Isola’s range covers thermally robust FR-4 (IS400, 185HR, 370HR, IS550H), high-speed digital (FR408HR, I-Speed, IS580G, I-Tera MT40, Tachyon 100G, TerraGreen 400G), RF/microwave (Astra MT77, I-Tera MT40 RF, TerraGreen RF) and polyimide specialty products.
- Most specified
- 370HR
- Range at 10 GHz
- Df 0.025 → 0.0015
- Dk 3.00 RF
- Astra MT77
- Polyimide
- P95 / P96
Isola overview
Who is Isola?
Isola Group is a US-headquartered maker of copper-clad laminate and prepreg that has made laminate since 1956, with production, R&D and sales across North America, Europe and Asia. Its grades, especially 370HR and FR408HR, are among the most frequently specified laminates on North American PCB drawings.
Isola groups its products into thermal reliability, high-speed digital, RF/microwave and specialty families. We build on all of them; 370HR and FR408HR have their own pages. When a drawing allows an equivalent we may propose a Shengyi or ITEQ grade, but only with your written approval.
Product line
Isola laminate product line by family.
| Family | Grades | Positioning | On our site |
|---|---|---|---|
| Thermal reliability | IS400, 185HR, 370HR, IS550H | Lead-free FR-4 from mid-Tg to very high thermal reliability | 370HR page |
| High speed digital | FR408HR, I-Speed, IS580G, I-Tera MT40, Tachyon 100G, TerraGreen 400G / 400GE / 400G2 | Mid-loss to extremely low-loss | FR408HR page |
| RF / microwave | Astra MT77, I-Tera MT40 (RF/MW), TerraGreen 400G RF/MW | Low-loss, stable Dk, PTFE alternatives | RF materials |
| Specialty | P95 / P25, P96 / P26 polyimide, P25N, FR406N No-Flo / Lo-Flo prepreg | High-temperature polyimide and no-flow prepreg | Polyimide |
Thermal reliability
Isola 185HR, 370HR, IS400 and IS550H thermal-reliability laminates.
IS400 is a lead-free mid-Tg epoxy (Tg 150 °C). 185HR and 370HR are standard-loss, thermally robust high-Tg epoxies (Tg 180 °C, Td 340 °C); 370HR is the one specified in thousands of designs for thick, high-layer-count boards. IS550H is a halogen-free, low-CTE, very high thermal-reliability system (Tg 200 °C, Td 400 °C, 2.0% z-expansion).
| Grade | Tg (°C) | Td (°C) | Z-expansion 50–260 °C | Dk / Df @ 10 GHz |
|---|---|---|---|---|
| IS400 | 150 | 330 | 3.3% | 3.80 / 0.026 |
| 185HR | 180 | 340 | 2.7% | 3.88 / 0.024 |
| 370HR | 180 | 340 | 2.8% | 3.92 / 0.025 |
| IS550H (halogen-free) | 200 | 400 | 2.0% | 4.43 / 0.016 |
High speed digital
Isola high-speed laminates: FR408HR, I-Speed, Isola Tachyon 100G and TerraGreen.
FR408HR (Df 0.0095) is Isola’s mid-loss FR-4 workhorse. I-Speed (Df 0.006) and halogen-free IS580G (Df 0.006, Tg 195 °C) are low-loss; I-Tera MT40 (Df 0.0031) and Tachyon 100G (Dk 3.02, Df 0.0021) are very low-loss for 56–112G; and the halogen-free TerraGreen 400G (Df 0.0017), 400GE (0.0026) and 400G2 (0.0015) are Isola’s most advanced ultra-low-loss materials for 112G and 224G-class designs.
| Grade | Tg (°C) | Dk @ 10 GHz | Df @ 10 GHz | Halogen-free | Typical data rate |
|---|---|---|---|---|---|
| FR408HR | 190 | 3.65 | 0.0095 | No | 10–25G |
| I-Speed | 180 | 3.63 | 0.006 | No | 25G, PCIe Gen 4 |
| IS580G | 195 | 3.80 | 0.006 | Yes | 25G |
| I-Tera MT40 | 215 | 3.45 | 0.0031 | No | 25–56G |
| Tachyon 100G | 215 | 3.02 | 0.0021 | No | 56–112G |
| TerraGreen 400GE | 200 | 3.29 | 0.0026 | Yes | 56–112G |
| TerraGreen 400G | 200 | 3.15 | 0.0017 | Yes | 112G |
| TerraGreen 400G2 | 200 | 3.10 | 0.0015 | Yes | 112–224G |
RF & microwave
Isola Astra MT77 and I-Tera MT40 RF and microwave laminates.
Astra MT77 is Isola’s very low-loss RF material (Dk 3.00, Df 0.0017 at 10 GHz, Tg 200 °C), used for automotive radar and mmWave antennas as a thermoset alternative to PTFE. I-Tera MT40 (RF/MW) offers Dk options from 3.38 to 3.75 with Df 0.0028–0.0035, and TerraGreen 400G RF/MW is a halogen-free option at Dk 3.15. Because they are thermosets they process more like FR-4 than PTFE and bond well in hybrid RF + digital stack-ups.
| Grade | Dk @ 10 GHz | Df @ 10 GHz | Tg (°C) |
|---|---|---|---|
| Astra MT77 | 3.00 | 0.0017 | 200 |
| I-Tera MT40 (RF/MW) | 3.38–3.75 | 0.0028–0.0035 | 215 |
| TerraGreen 400G RF/MW | 3.15 | 0.0018 | 210 |
Compare with Rogers, Taconic and other RF materials.
Polyimide & no-flow
Isola P95/P96 polyimide and Isola FR406N no-flow prepreg.
Isola’s specialty range includes P95 / P25 (UL HB) and P96 / P26 (UL V-0) polyimide laminate and prepreg (Tg 260 °C, Td 396–416 °C, 1.5% z-expansion) for military, aerospace and down-hole boards, P25N polyimide no-flow prepreg, and FR406N No-Flo / Lo-Flo prepreg for rigid-flex and heat-sink bonding. For another rigid polyimide option see Arlon 85N.
| Grade | Type | Tg (°C) | Td (°C) |
|---|---|---|---|
| P95 / P25 | Polyimide laminate / prepreg, UL HB | 260 | 416 |
| P96 / P26 | Polyimide laminate / prepreg, UL V-0 | 260 | 396 |
| P25N | Polyimide no-flow prepreg | 250 | 383 |
| FR406N | No-Flo / Lo-Flo epoxy prepreg | 170 | 300 |
Choosing a grade
Which Isola laminate should I specify?
| If your board… | Isola grade | Other brands we can propose |
|---|---|---|
| Needs high-Tg, CAF-resistant FR-4 | 370HR / 185HR | Shengyi S1000-2M, ITEQ IT-180A |
| Needs halogen-free high reliability | IS550H | Shengyi S1190G |
| Runs 10–25G | FR408HR / I-Speed | ITEQ IT-170GRA1, Shengyi S7439, Megtron 4 |
| Runs 56–112G | I-Tera MT40 / Tachyon 100G | Megtron 7, Synamic 6N, IT-988GSE |
| Runs 112–224G | TerraGreen 400G / 400G2 | Megtron 8, Synamic 9GN, IT-999GSE |
| Is a 77 GHz radar or mmWave antenna | Astra MT77 | Rogers RO3003, Shengyi mmWave77 |
| Must survive 200 °C+ service | P95 / P96 polyimide | Arlon 85N |
RFQ
What to include in an Isola laminate RFQ.
- Laminate name and grade exactly as on your drawing, or “or equivalent” if substitution is allowed
- Isola grade (e.g. “Isola 370HR”, “Tachyon 100G”) or the IPC-4101 slash sheet if an equivalent is acceptable
- Data rate or frequency for low-loss layers
- Glass style and copper type on high-speed layers
- Layer count, finished thickness and tolerance
- Impedance targets and reference layers
- IPC class, quantity and schedule
FAQ
Material questions.
What is the most common Isola PCB material?
370HR, a 180 °C Tg, CAF-resistant FR-4 used in thousands of designs. See the 370HR page.
What is Isola Tachyon 100G?
A very low-loss laminate for 56–112G channels: Tg 215 °C, Dk 3.02 and Df 0.0021 at 10 GHz per the Isola product guide.
What is Isola Astra MT77?
Isola’s very low-loss RF laminate (Dk 3.00, Df 0.0017 at 10 GHz) for automotive radar and mmWave antennas. It processes like a thermoset rather than PTFE.
What is the difference between Isola 185HR and 370HR?
Both are 180 °C Tg, 340 °C Td thermally robust epoxies with similar loss. 370HR is more widely specified; 185HR has slightly lower z-axis expansion (2.7% vs 2.8%).
Is Isola FR406 still available?
Isola now lists FR406N as a No-Flo / Lo-Flo specialty prepreg for rigid-flex and bonding. For standard high-Tg laminate, 370HR or 185HR are the current grades.
Which Isola laminates are halogen-free?
IS550H, IS580G and the TerraGreen 400G, 400GE and 400G2 families, per the Isola product guide.
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