HF-140 and HF-170 are Kingboard's halogen-free laminate series—the "HF" designation stands for Halogen-Free, indicating compliance with IEC 61249-2-21 requirements for bromine, chlorine, antimony, and red phosphorus content. These materials address the growing global demand for environmentally compliant PCB substrates driven by EU RoHS/WEEE directives, automotive OEM requirements, and corporate sustainability mandates, while delivering genuine high-reliability performance including low Z-axis CTE, anti-CAF capability, and full lead-free compatibility.
HF-140 with Tg 141°C (DSC) meets IPC-4101E/127 and serves as the halogen-free counterpart to KB-6164 in Kingboard's portfolio—a normal-Tg, low-CTE, lead-free compatible material. HF-170 with Tg 180°C (DSC) meets IPC-4101E/127/128/130 and positions as the halogen-free alternative to KB-6167F—a high-Tg platform for servers, backplanes, and automotive electronics. Both share the fundamental engineering advantage of standard FR-4 processing with halogen-free compliance, anti-CAF performance, and excellent thermal endurance.
In This Guide
- Why Halogen-Free PCB Materials Are Required for Modern Electronics
- HF-140 Verified Datasheet Specifications from Official Kingboard PDF
- HF-170 Verified Datasheet Specifications from Official Kingboard PDF
- HF-140 vs HF-170: Technical Comparison and Selection Criteria
- PP-HF140 and PP-HF170 Prepreg Systems and Dk/Df Data at 1 GHz
- Anti-CAF Performance and Electrochemical Migration Resistance
- HF-140/HF-170 vs KB-6164/KB-6167F and KB-6165G: Halogen-Free Material Selection
- Target Applications: Automotive, Telecom, Server, and EU-Compliant Consumer Electronics
- How to Order HF-140 and HF-170 PCBs from APTPCB
Why Halogen-Free PCB Materials Are Required for Modern Electronics
Halogen-free PCB materials eliminate bromine and chlorine-based flame retardants that produce toxic dioxins and furans when incinerated during electronics waste processing. The regulatory and commercial drivers are substantial and accelerating across industries.
The EU's RoHS and WEEE directives, while not directly banning halogenated flame retardants in PCB substrates, have created a strong market preference for halogen-free solutions. Major European automotive OEMs including Volkswagen, BMW, and Stellantis increasingly mandate halogen-free PCB substrates in their procurement specifications. Japanese electronics manufacturers have led halogen-free adoption for over a decade, and Chinese environmental regulations are following similar trajectories.
IEC 61249-2-21 defines halogen-free as: bromine <900 ppm, chlorine <900 ppm, and total bromine plus chlorine <1500 ppm. Both HF-140 and HF-170 comply with these limits while additionally being free of antimony and red phosphorus—addressing the complete spectrum of environmental concerns in flame retardant chemistry.
The technical challenge with halogen-free formulations is achieving UL 94 V-0 flame retardancy without the highly effective but environmentally problematic brominated flame retardants. Kingboard's HF series uses proprietary phosphorus-nitrogen synergistic flame retardant systems that meet V-0 requirements while maintaining thermal and mechanical properties comparable to their halogenated counterparts.
HF-140 Verified Datasheet Specifications from Official Kingboard PDF
All values sourced from Kingboard's official HF-140 product datasheet. Specimen thickness: 1.6 mm (8×7628 construction). ✓ indicates values verified against the official PDF.
HF-140 Thermal Properties
| Test Item | Test Method | Condition | Spec (IPC-4101E/127) | Typical Value ✓ |
|---|---|---|---|---|
| Thermal Stress | 2.4.13.1 | Float 288°C, Unetched | ≥10 sec | ≥240 sec |
| Glass Transition (Tg) | 2.4.25 | E-2/105, DSC | ≥140°C | 141°C |
| Z-axis CTE Alpha 1 | 2.4.24 | TMA | ≤60 ppm/°C | 45 ppm/°C |
| Z-axis CTE Alpha 2 | 2.4.24 | TMA | ≤300 ppm/°C | 254 ppm/°C |
| Z-axis Expansion (50–260°C) | 2.4.24 | TMA | ≤4.0% | 3.3% |
| X/Y CTE | 2.4.24 | 40–125°C | — | 12/15 ppm/°C |
| T-260 | 2.4.24.1 | TMA | ≥30 min | >60 min |
| T-288 | 2.4.24.1 | TMA | ≥5 min | >5 min |
| Td (5% weight loss) | 2.4.24.6 | TGA | ≥310°C | 350°C |
| Flammability | UL94 | E-24/23 | V-0 | V-0 |
HF-140 Electrical Properties
| Test Item | Test Method | Condition | Spec | Typical Value ✓ |
|---|---|---|---|---|
| Surface Resistivity | 2.5.17.1 | C-96/35/90 | ≥10⁴ MΩ | 2.7×10⁸ MΩ |
| Volume Resistivity | 2.5.17.1 | C-96/35/90 | ≥10⁶ MΩ·cm | 5.3×10⁹ MΩ·cm |
| Dielectric Breakdown | 2.5.6 | D-48/50+D-0.5/23 | ≥40 kV | ≥45 kV |
| Dk @1 MHz | 2.5.5.2 | Etched, R/C 50% | ≤5.4 | 4.8 |
| Dk @1 GHz | 2.5.5.2 | Etched, R/C 50% | — | 4.6 |
| Df @1 MHz | 2.5.5.2 | Etched, R/C 50% | ≤0.035 | 0.012 |
| Df @1 GHz | 2.5.5.2 | Etched, R/C 50% | — | 0.013 |
| CTI | IEC 60112 | A | — | >175V |
| Arc Resistance | 2.5.1 | D-48/50+D-0.5/23 | ≥60 sec | 120 sec |
HF-140 Mechanical Properties
| Test Item | Test Method | Condition | Spec | Typical Value ✓ |
|---|---|---|---|---|
| Peel Strength (1 oz) | 2.4.8 | 125°C | ≥0.70 N/mm | 1.3 N/mm |
| Peel Strength (1 oz) | 2.4.8 | Float 288°C/10 sec | ≥1.05 N/mm | 1.4 N/mm |
| Peel Strength (1 oz) | 2.4.8 | After Process Solution | ≥0.80 N/mm | 1.1 N/mm |
| Flexural Strength (MD) | 2.4.4 | — | ≥415 N/mm² | 550 N/mm² |
| Flexural Strength (XD) | 2.4.4 | — | ≥345 N/mm² | 490 N/mm² |
| Moisture Absorption | 2.6.2.1 | D-24/23 | ≤0.5% | 0.11% |
HF-170 Verified Datasheet Specifications from Official Kingboard PDF
All values sourced from Kingboard's official HF-170 product datasheet. Specimen thickness: 1.6 mm (8×7628 construction). ✓ indicates values verified against the official PDF.
HF-170 Thermal Properties
| Test Item | Test Method | Condition | Typical Value ✓ |
|---|---|---|---|
| Thermal Stress | 2.4.13.1 | Float 288°C, Unetched | ≥240 sec |
| Glass Transition (Tg, DSC) | 2.4.25 | DSC | 180°C |
| Glass Transition (Tg, DMA) | 2.4.24.4 | DMA | 190°C |
| Z-axis CTE Alpha 1 | 2.4.24 | TMA | 45 ppm/°C |
| Z-axis CTE Alpha 2 | 2.4.24 | TMA | 220 ppm/°C |
| Z-axis Expansion (50–260°C) | 2.4.24 | TMA | 2.2% |
| X/Y CTE | 2.4.24 | 40–125°C | 12/15 ppm/°C |
| T-260 | 2.4.24.1 | TMA | >60 min |
| T-288 | 2.4.24.1 | TMA | >60 min |
| Td (5% weight loss) | 2.4.24.6 | TGA | 385°C |
| Flammability | UL94 | E-24/125 | V-0 |
HF-170 Electrical Properties
| Test Item | Test Method | Condition | Typical Value ✓ |
|---|---|---|---|
| Surface Resistivity | 2.5.17.1 | C-96/35/90 | 3.6×10⁸ MΩ |
| Volume Resistivity | 2.5.17.1 | C-96/35/90 | 4.7×10⁹ MΩ·cm |
| Dielectric Breakdown | 2.5.6 | D-48/50+D-0.5/23 | ≥45 kV |
| Dk @1 GHz | IEC 61189-2-721 | Etched, R/C 50% | 4.6 |
| Dk @10 GHz | IEC 61189-2-721 | Etched, R/C 50% | 4.4 |
| Df @1 GHz | IEC 61189-2-721 | Etched, R/C 50% | 0.011 |
| Df @10 GHz | IEC 61189-2-721 | Etched, R/C 50% | 0.013 |
| CTI | IEC 60112 | Etched/0.1% NH₄Cl | ≥200V |
| Arc Resistance | 2.5.1 | D-48/50+D-0.5/23 | 123 sec |
HF-170 Mechanical Properties
| Test Item | Test Method | Condition | Typical Value ✓ |
|---|---|---|---|
| Peel Strength (1 oz) | 2.4.8 | Float 288°C/10 sec | 1.40 N/mm |
| Flexural Strength (MD) | 2.4.4 | — | 590 N/mm² |
| Flexural Strength (XD) | 2.4.4 | — | 510 N/mm² |
| Moisture Absorption | 2.6.2.1 | D-24/23 | 0.11% |
HF-170 uses Dielectric Constant test method IEC 61189-2-721, while HF-140 uses IPC-TM-650 2.5.5.2—a difference worth noting for correlation testing. HF-170's Df of 0.011 at 1 GHz is notably lower than standard high-Tg FR-4 (KB-6167F at 0.016), suggesting a mid-loss resin formulation optimized for the halogen-free chemistry.
HF-140 vs HF-170: Technical Comparison and Selection Criteria
| Property | HF-140 ✓ | HF-170 ✓ | Difference |
|---|---|---|---|
| Tg (DSC) | 141°C | 180°C | HF-170 +39°C higher |
| Tg (DMA) | — | 190°C | HF-170 only |
| Td (TGA) | 350°C | 385°C | HF-170 +35°C higher |
| Z-CTE alpha1 | 45 ppm/°C | 45 ppm/°C | Same |
| Z-CTE alpha2 | 254 ppm/°C | 220 ppm/°C | HF-170 13% lower |
| Z-CTE 50–260°C | 3.3% | 2.2% | HF-170 33% lower |
| T-260 | >60 min | >60 min | Same |
| T-288 | >5 min | >60 min | HF-170 far superior |
| Dk @1 GHz | 4.6 | 4.6 | Same |
| Df @1 GHz | 0.013 | 0.011 | HF-170 15% lower |
| CTI | >175V | ≥200V | HF-170 higher |
| IPC Slash Sheet | /127 | /127/128/130 | HF-170 broader |
| Halogen-Free | Yes | Yes | Both |
| Anti-CAF | Yes | Yes | Both |
| UL File | E123995 | E123995 | Same |
Choose HF-140 when: Halogen-free compliance is the primary driver, operating temperature stays below 100°C, board thickness ≤1.6 mm, and cost is critical. Consumer electronics, LED lighting, industrial instruments requiring EU environmental compliance.
Choose HF-170 when: Maximum thermal reliability is needed alongside halogen-free compliance. The T-288 >60 min (versus HF-140's >5 min) and Z-CTE 2.2% (versus 3.3%) make HF-170 the clear choice for automotive electronics, server boards, high-complexity multilayer boards, and applications with aggressive lead-free reflow requirements.
PP-HF140 and PP-HF170 Prepreg Systems and Dk/Df Data at 1 GHz
PP-HF140 Prepreg Dk/Df Data (Verified ✓)
| Glass Style | R/C (%) | Dk @1 GHz (±0.2) | Df @1 GHz (±10%) | Pressed Thickness (mil) |
|---|---|---|---|---|
| 106 | 74±2 | 4.2 | 0.017 | 1.9±0.30 |
| 106 | 76±2 | 4.1 | 0.018 | 2.4±0.40 |
| 1067 | 72±2 | 4.2 | 0.017 | 2.4±0.30 |
| 1067 | 74±2 | 4.1 | 0.018 | 2.8±0.40 |
| 1080 | 62±2 | 4.3 | 0.014 | 2.8±0.30 |
| 1080 | 65±2 | 4.2 | 0.014 | 3.1±0.30 |
| 1080 | 68±2 | 4.2 | 0.014 | 3.4±0.30 |
| 3313 | 52±2 | 4.5 | 0.013 | 3.5±0.30 |
| 3313 | 55±2 | 4.4 | 0.013 | 3.8±0.30 |
| 3313 | 58±2 | 4.4 | 0.013 | 4.0±0.30 |
| 2116 | 52±2 | 4.5 | 0.013 | 4.6±0.30 |
| 2116 | 55±2 | 4.5 | 0.013 | 5.1±0.30 |
| 2116 | 58±2 | 4.4 | 0.013 | 5.4±0.30 |
| 1506 | 48±2 | 4.6 | 0.012 | 6.9±0.50 |
| 1506 | 50±2 | 4.5 | 0.012 | 7.3±0.50 |
| 7628 | 42±2 | 4.7 | 0.012 | 7.1±0.50 |
| 7628 | 45±2 | 4.6 | 0.012 | 7.5±0.50 |
| 7628 | 48±2 | 4.6 | 0.012 | 8.0±0.50 |
A notable observation: PP-HF140 prepreg Df values range from 0.012 to 0.018 across glass styles. The 1080 glass styles at high resin content show Df 0.014—lower than the laminate-level 0.013, suggesting that impedance-critical designs should use specific prepreg Dk/Df values rather than the laminate-level data. Our stackup design service uses prepreg-specific values for accurate impedance modeling.
Lamination Process Parameters
| Parameter | HF-140 ✓ | HF-170 |
|---|---|---|
| Heat-up rate | 1.5–2.5°C/min (80–140°C) | 1.5–2.5°C/min (est.) |
| Curing temperature | >180°C | >190°C (est.) |
| Curing time | >50 min | >60 min (est.) |
| Curing pressure | 350±50 PSI | 350±50 PSI (est.) |
| Prepreg storage | Max 50% RH, Max 23°C, 90 days | Same |
| Cold storage | Max 5°C, 180 days (4h acclimate) | Same |
Anti-CAF Performance and Electrochemical Migration Resistance
Both HF-140 and HF-170 feature anti-CAF (Conductive Anodic Filament) capability as listed in their official datasheets. CAF resistance is critical for PCB designs with fine-pitch via arrays, high-voltage spacing requirements, and exposure to humidity—conditions increasingly common in automotive under-hood electronics and outdoor telecom equipment.
CAF forms when electrochemical migration along glass fiber/resin interfaces creates conductive paths between adjacent conductors. The halogen-free resin chemistry in HF-140/HF-170 provides a glass-resin bond that resists this migration mechanism, maintaining insulation resistance over the product lifetime even under bias voltage and humidity stress.
For automotive applications requiring AEC-Q200 qualification or designs with via-to-via spacing below 0.3 mm at voltage differentials above 50V, the anti-CAF performance of HF-140/HF-170 provides measurable reliability improvement versus standard halogen-free materials without anti-CAF designation.
HF-140/HF-170 vs KB-6164/KB-6167F and KB-6165G: Halogen-Free Material Selection
Understanding how the HF series relates to Kingboard's broader portfolio is essential for material selection:
| Property | HF-140 ✓ | KB-6164 ✓ | HF-170 ✓ | KB-6167F ✓ | KB-6165G |
|---|---|---|---|---|---|
| Tg (DSC) | 141°C | 140°C | 180°C | 175°C | ~150°C |
| Td (TGA) | 350°C | 330°C | 385°C | 349°C | ~340°C |
| Z-CTE 50–260 | 3.3% | 3.5% | 2.2% | 2.6% | ~3.0% |
| T-260 | >60 min | >60 min | >60 min | >60 min | >60 min |
| T-288 | >5 min | >15 min | >60 min | >35 min | — |
| Dk @1 GHz | 4.6 | 4.6 | 4.6 | 4.6 | ~4.6 |
| Df @1 GHz | 0.013 | 0.016 | 0.011 | 0.016 | ~0.014 |
| Anti-CAF | Yes | Yes | Yes | Yes | Yes |
| Halogen-Free | Yes | No | Yes | No | Yes |
| IPC Slash | /127 | /101 | /127/128/130 | /126 | /124 |
Key observations from the comparison:
HF-140 vs KB-6164: Nearly identical Tg and CTE, but HF-140 provides halogen-free compliance with a higher Td (350°C vs 330°C) and lower Df (0.013 vs 0.016). HF-140 is the direct halogen-free upgrade from KB-6164.
HF-170 vs KB-6167F: HF-170 surpasses KB-6167F in every thermal metric—higher Tg (180 vs 175°C), higher Td (385 vs 349°C), lower Z-CTE (2.2% vs 2.6%), and superior T-288 (>60 vs >35 min)—while adding halogen-free compliance and lower Df (0.011 vs 0.016). HF-170 is not merely a halogen-free KB-6167F alternative; it is a performance upgrade.
HF-170 vs KB-6165G: KB-6165G provides halogen-free at mid-Tg (150°C), while HF-170 provides halogen-free at high-Tg (180°C). For applications requiring both halogen-free and high thermal performance, HF-170 is the clear choice.
Target Applications: Automotive, Telecom, Server, and EU-Compliant Consumer Electronics
Automotive Electronics (HF-170): European automotive OEMs increasingly mandate halogen-free substrates. HF-170's combination of Tg 180°C, Z-CTE 2.2%, T-288 >60 min, and anti-CAF makes it suitable for ADAS modules, body control units, and infotainment systems operating in the -40°C to +125°C range. The IPC-4101E/127/128/130 compliance provides qualification documentation that automotive quality systems require.
Telecom Infrastructure (HF-170): High-end servers and backpanel applications are explicitly listed in HF-170's application section. The Z-CTE 2.2% supports high-complexity multilayer boards with via aspect ratios up to 12:1, while halogen-free compliance meets corporate environmental policies at major telecom equipment manufacturers.
Consumer Electronics with EU Compliance (HF-140): LED drivers, consumer IoT devices, smart home products, and computer peripherals where EU market access requires demonstrated environmental responsibility. HF-140's Tg 141°C and T-260 >60 min handle standard lead-free assembly, while the lower cost versus HF-170 preserves BOM margins.
Industrial Equipment (HF-140/HF-170): Instruments, motor controllers, and automation equipment where end-of-life disposal regulations apply. The anti-CAF capability addresses humidity exposure in industrial environments.
Wireless Communication Infrastructure (HF-170): Base station control boards, small cell digital processing boards, and network switching equipment where both environmental compliance and high-reliability thermal performance are specified.
How to Order HF-140 and HF-170 PCBs from APTPCB
Upload your design files with halogen-free and thermal requirements. Our engineering team evaluates HF-140/HF-170 suitability, simulates impedance using prepreg-specific Dk values, and provides DFM analysis optimized for halogen-free processing. For projects requiring environmental compliance documentation, we provide material certificates confirming IEC 61249-2-21 compliance. Complete fabrication and assembly quotes include material, surface finish selection, and halogen-free verification.