Complete Bergquist HT-07006 specifications: thermal conductivity 4.1 W/m-K, thermal resistance 0.71 °C·cm²/W, 11 kVAC breakdown, 140°C max operating temperature. Learn how this Thermal Clad MCPCB compares to HT-04503 and MP-06503, target applications, fabrication requirements, and design guidance from a PCB engineer’s perspective.

When you’re designing a board that handles serious power density — motor drives, solid-state relays, high-current LED arrays, solar receivers — standard FR4 stops being a viable option pretty quickly. The thermal resistance of a conventional epoxy laminate simply can’t keep junction temperatures in check at the watt densities these applications demand. That’s when engineers start looking at metal core PCBs (MCPCBs) and, specifically, at Henkel Bergquist’s Thermal Clad dielectric family.

The Bergquist HT-07006 is one of the most specified MCPCBs in that family. It’s the high-temperature, higher-isolation variant in the Thermal Clad lineup, carrying the thickest dielectric in the standard HT series at 6 mil (152 µm). This article goes through everything you need to know: what the HT-07006 actually is, the full verified specifications from the official technical data sheet, how it compares to the rest of the Thermal Clad range, where it belongs and where it doesn’t, and the fabrication details that will affect your design and manufacturing planning.

What Is the Bergquist HT-07006 MCPCB?

The Bergquist HT-07006 is a metal core PCB dielectric material manufactured under Henkel’s Thermal Clad product line. It is classified as a High Temperature (HT) dielectric — the “HT” in the part number is not a marketing label, it refers to the dielectric’s specific formulation, which is engineered to resist thermal degradation at elevated continuous operating temperatures better than standard epoxy-based IMS (Insulated Metal Substrate) materials.

The part number encodes two key specifications: “07” refers to the nominal 7-mil dielectric thickness, and “006” indicates a thermal resistance of approximately 0.06 in²-°F/BTU (expressed in metric as 0.71 °C·cm²/W). Understanding this nomenclature matters because it’s how Bergquist differentiates the entire Thermal Clad product line — thickness and thermal resistance are the primary selection parameters.

The Thermal Clad Technology Behind HT-07006

The technical advantage of Thermal Clad doesn’t come from the aluminum or copper base metal — it comes from the dielectric layer itself. Bergquist uses a proprietary polymer/ceramic composite blend for this layer. The polymer component provides electrical isolation, thermal aging resistance, and strong adhesion to both the base metal and the copper circuit foil above it. The ceramic filler drives up thermal conductivity while maintaining high dielectric strength. The result is a layer that achieves 2.2 W/m-K dielectric thermal conductivity and 11 kVAC breakdown voltage at a dielectric thickness of only 6 mil (152 µm).

This combination is mechanically more robust than thick-film ceramic substrates and direct bond copper (DBC) construction, while being significantly more cost-effective to fabricate at volume.

Bergquist HT-07006 Complete Specifications

The following data is taken directly from the official Bergquist / Henkel Technical Data Sheet (TDS) for BERGQUIST TCLAD TIC_TIP HT 07006, revision March 2019.

Physical Properties

Property	Value	Test Method
Technology	Epoxy	—
Appearance	White	—
Dielectric Thickness	0.006 in (152 µm / 6 mil)	—
Peel Strength @ 25°C	1.1 N/mm	ASTM D2861
Glass Transition Temperature (Tg)	150°C	ASTM E1356
CTE — XY/Z Axis Below Tg	25 µm/m·°C	ASTM D3386
CTE — XY/Z Axis Above Tg	95 µm/m·°C	ASTM D3386
Storage Modulus @ 25°C	16 GPa	ASTM D4065
Storage Modulus @ 150°C	7 GPa	ASTM D4065

Electrical Properties

Property	Value	Test Method
Dielectric Constant	7	ASTM D150
Dissipation Factor @ 1 kHz	0.0038	ASTM D150
Dissipation Factor @ 1 MHz	0.0129	ASTM D150
Capacitance	43 pF/cm²	ASTM D150
Volume Resistivity	1×10¹⁴ Ω·m	ASTM D257
Surface Resistivity	1×10¹³ Ω/sq	ASTM D257
Breakdown Voltage	11 kVAC	ASTM D149

Thermal Properties

Property	Value	Test Method
Product Thermal Conductivity	4.1 W/m-K	MET 5.4-01-40000
Dielectric Thermal Conductivity	2.2 W/m-K	ASTM D5470
Thermal Resistance	0.71 °C·cm²/W	ASTM D5470
Thermal Impedance	0.7 °C/W	MET 5.4-01-40000

Chemical Properties

Property	Value	Test Method
Water Vapor Retention	0.21 wt%	ASTM E595
Out-Gassing Total Mass Loss	0.23 wt%	ASTM E595
Collect Volatile Condensable Material	<0.01 wt%	ASTM E595

Agency Ratings and Compliance

Property	Value	Standard
Maximum Operating Temperature	140°C	UL 746B
Flammability Rating	V-0	UL 94
CTI (ASTM)	0	ASTM D3638
CTI (IEC)	600	IEC 60112
Solder Limit Rating (60 sec)	325°C	UL 796

A few practical callouts from this data:

The 4.1 W/m-K product thermal conductivity is the system-level figure that includes the effect of the metal substrate and copper foil combined. The 2.2 W/m-K dielectric-only value is the number relevant to thermal resistance calculations in your design — it’s the bottleneck in the heat path.

The 140°C maximum continuous operating temperature (UL 746B) is the rated safe-use limit, not the point of failure. The Tg of 150°C means the dielectric begins softening 10°C above that UL limit, which is why Bergquist rates it conservatively. Design to stay well under 140°C.

The 11 kVAC breakdown voltage is the key differentiator between HT-07006 and HT-04503. The thicker 6-mil dielectric of the HT-07006 provides higher isolation headroom — a direct trade-off against thermal resistance versus the thinner HT-04503.

The 325°C solder limit for 60 seconds confirms compatibility with both lead-free SAC reflow (peak ~260°C) and eutectic AuSn bonding (280°C).

Bergquist HT-07006 vs. Other Thermal Clad Dielectrics

Understanding where HT-07006 sits in the Bergquist lineup requires comparing it directly with the adjacent products in the Thermal Clad family. Here’s a comprehensive side-by-side:

Parameter	HT-04503	HT-07006	MP-06503	HT-09009	HPL-03015
Dielectric Thickness (mil/µm)	3 / 76	6 / 152	3 / 76	9 / 229	1.5 / 38
Thermal Resistance (°C·cm²/W)	0.45	0.71	0.65	0.90	0.30
Dielectric Thermal Conductivity (W/m-K)	2.2	2.2	1.3	2.2	3.0
Breakdown Voltage (kVAC)	8.5	11.0	8.5	20.0	2.5
Dielectric Constant	7	7	6	7	6
Max Operating Temp. (°C)	140	140	130	150	—
Flammability	V-0	V-0	V-0	V-0	—
Tg (°C)	150	150	90	150	185
Peel Strength (N/mm)	1.1	1.1	1.6	1.1	0.9

What this table makes clear:

The HT-07006 is essentially a higher-isolation version of the HT-04503. Both share the same dielectric thermal conductivity (2.2 W/m-K), same Tg (150°C), same max operating temperature, and same flammability rating. The HT-07006 simply doubles the dielectric thickness from 3 mil to 6 mil, which raises breakdown voltage from 8.5 kVAC to 11 kVAC and also raises thermal resistance from 0.45 to 0.71 °C·cm²/W. Thicker dielectric = better electrical isolation, but worse thermal performance — that trade-off is the central design decision between HT-04503 and HT-07006.

The MP-06503, with its lower Tg of 90°C and 1.3 W/m-K dielectric conductivity, is a lower-cost option for less demanding thermal environments. When your operating temperature stays well below 90°C and you don’t need the high-temperature stability of the HT series, MP-06503 can reduce material cost without compromising reliability.

The HPL-03015 (High Power Lighting) series is a specialty variant with a 1.5-mil dielectric and 3.0 W/m-K conductivity — optimized for LED arrays where the shortest possible thermal path matters more than isolation voltage. It’s not a substitute for HT-07006 in isolation-critical applications.

When to Use Bergquist HT-07006: Target Applications

High Watt-Density Power Electronics

The HT-07006’s most common home is in power conversion applications: DC-DC converters, AC-DC power supplies, inverter stages, and similar circuits where power MOSFETs, IGBTs, or SiC/GaN switches are switching high currents. In these designs, the thermal resistance between the device junction and the ambient environment is the critical parameter limiting how hard you can push the silicon. The HT-07006’s 0.71 °C·cm²/W thermal resistance, combined with an aluminum or copper base plate that can be directly mounted to a chassis or heatsink, dramatically shortens that thermal path compared to FR4 with thermal interface materials stacked in between.

Solid-State Relays and Motor Drives

Solid-state relay manufacturers routinely specify Bergquist HT-07006 because it combines the electrical isolation needed between the control and power circuits (11 kVAC breakdown) with the thermal performance needed to keep switching devices from overheating at rated current. Motor drive applications share the same requirements: high isolation voltage, continuous high-power operation, and temperature stability up to 140°C in enclosed industrial enclosures.

High-Reliability LED Applications

While the HPL series is optimized for the most demanding LED thermal performance, the HT-07006 is often preferred for high-reliability LED applications — particularly where the operating environment involves elevated ambient temperatures, multiple thermal cycles, or applications where the higher breakdown voltage of HT-07006 provides additional margin. Street lighting, industrial high-bay luminaires, and automotive exterior lighting are typical examples.

Solar Receivers and Energy Conversion Systems

Solar receiver electronics, particularly bypass diode circuits and maximum power point tracking (MPPT) converters in photovoltaic arrays, benefit from the HT-07006’s combination of outdoor-survivable thermal stability, high isolation voltage, and compatibility with aluminum substrates that can be integrated directly into module structures.

Heat-Rail and Bus Bar Applications

The HT-07006’s 11 kVAC isolation rating makes it suitable for heat-rail assemblies where the board structure itself acts as a thermal interface between power components and a shared metallic cooling structure, while maintaining electrical isolation between the circuit and chassis.

Eutectic AuSn Die Attach

For applications that require eutectic gold-tin (80Au/20Sn) die bonding — common in high-reliability optoelectronics, RF power modules, and military/aerospace assemblies — the HT-07006’s 325°C solder limit at 60 seconds is a critical specification. AuSn eutectic soldering occurs at ~280°C, and the material’s ability to survive that process without dielectric degradation is a direct enabler for this assembly technique.

When HT-07006 Is Not the Right Choice

Understanding when not to use a material is as useful as knowing when to specify it.

Scenario	Better Alternative	Reason
Maximum thermal performance, lower isolation voltage needed	HT-04503	Half the thermal resistance (0.45 vs. 0.71 °C·cm²/W)
Low-power LED modules, operating temp < 90°C	MP-06503	Lower cost; sufficient for the thermal environment
Ultra-high-density LED arrays, sub-76µm dielectric needed	HPL-03015	Thinner dielectric, higher conductivity (3.0 W/m-K)
Multilayer board needed	HT-09009 (multi-layer variant)	HT-07006 is fundamentally a single-dielectric IMS
High-frequency RF/microwave	Rogers RO4003C, PTFE laminates	HT-07006’s Dk of 7 and Df of 0.013 are unsuitable above 1 GHz
Extreme temperature environment (>150°C Tg needed)	Polyimide MCPCBs, Arlon PCB CE/BT systems	HT-07006 Tg is 150°C; not suitable for applications requiring >140°C continuous operation

Bergquist HT-07006 Design and Fabrication Considerations

Available Configurations

The HT-07006 is available in panel form (for PCB fabrication) and pre-made circuit configurations. It works with both aluminum and copper base metals:

• Aluminum substrates: 5052 and 1100 alloy aluminum are the common choices. 5052 offers better mechanical strength; 1100 is softer and easier to machine but has slightly higher thermal conductivity.
• Copper substrates: Higher thermal conductivity base (copper at ~380 W/m-K vs. aluminum at ~160 W/m-K), preferred for the most demanding thermal applications. Higher material and machining cost.

Copper Foil and Trace Current Capability

Per IPC-4562, copper foil thickness is certified to an area weight, not a direct thickness measurement. Nominal 1 oz copper is 35 µm (0.0014″). HT-07006 boards are available with standard copper weights from 1 oz up to 3 oz or heavier for high-current applications. One of the genuine advantages of Thermal Clad over FR4-based approaches is that the copper circuit layer can carry higher currents because the underlying metal substrate acts as an additional heat spreader — you’re not solely relying on the trace geometry to manage thermal rise.

Surface Finishes Compatible with HT-07006

Surface Finish	Compatibility	Notes
HASL (Lead-Free)	Yes	Most common for cost-sensitive applications
ENIG (Electroless Nickel Immersion Gold)	Yes	Preferred for fine-pitch components and wire bonding
Immersion Silver	Yes	Good solderability; check shelf life requirements
OSP	Yes	Low cost; shorter shelf life
Hard Gold	Yes, with care	For edge connectors and contact areas
Eutectic AuSn	Yes	The 325°C solder limit directly enables this finish

Drilling and Routing Notes

Metal core PCBs require different tooling than FR4. Key points for your fabricator:

Drill speeds and feed rates must be optimized for the aluminum or copper base — typical FR4 parameters will cause excessive tool wear or smearing. Scoring or V-groove depaneling is preferred for aluminum-base HT-07006 boards; router-based depaneling generates more heat and aluminum debris that must be managed. Isolated vias through the board can be created, but require a sleeve or through-hole technique to maintain isolation from the base metal.

Storage Requirements

Per the TDS, store HT-07006 panels in their unopened containers in a dry location at 5–25°C for a shelf life of 12 months. Exposure to humidity before lamination can degrade adhesion and dielectric properties. This is a standard IMS handling requirement, but worth confirming your fabricator follows it.

HT-07006 vs. Standard FR4: Why the Thermal Difference Matters

A lot of engineers understand intuitively that MCPCB outperforms FR4 thermally, but the magnitude of the difference is worth quantifying. FR4 has a thermal conductivity of approximately 0.25–0.35 W/m-K. The HT-07006 dielectric layer alone is 2.2 W/m-K — roughly 6–9× higher. Once you add the aluminum or copper base metal into the thermal path, the difference in junction-to-ambient thermal resistance for a surface-mount power device becomes dramatic.

Parameter	Standard FR4 + TIM + Heatsink	HT-07006 on Aluminum + Heatsink
Laminate thermal conductivity	0.25–0.35 W/m-K	2.2 W/m-K (dielectric)
Thermal interfaces in heat path	2–3 (TIM layers, pad contacts)	1 (dielectric only)
Board-to-heatsink attachment	Mechanical with TIM	Direct bolt or adhesive to base metal
Operating temp at same power	Higher (limited by FR4)	Lower (better margin from Tg)
Design complexity for thermal management	Heat sink attachment, thermal vias, copper pours required	Simplified; base metal acts as spreader

For designs where the choice between FR4 and MCPCB is genuinely marginal (low power density, good airflow, components rated for wide temperature range), FR4 with copper pours and thermal vias can be a valid choice. But once you’re above approximately 5–10 W dissipated in a concentrated area with limited airflow, the HT-07006’s thermal architecture starts delivering real system-level benefits: smaller form factor, lower component temperatures, fewer external thermal management components, and longer service life.

Useful Resources for Bergquist HT-07006 PCB Engineering

These references belong in your materials library if you’re working with Thermal Clad products:

Bergquist Thermal Clad Selection Guide (Digikey hosted) — Comprehensive comparison of all Thermal Clad dielectrics, thermal impedance charts, and design application guidance: https://media.digikey.com/pdf/Data%20Sheets/Bergquist%20PDFs/ThermalCladSelectionGuide.pdf

Bergquist HT-07006 Official TDS (Henkel/MCL PCB hosted) — Complete technical data sheet with all tested properties: https://www.mclpcb.com/wp-content/uploads/2021/05/Bergquist-HT-07006.pdf

Henkel Electronics — Bergquist Product Portal — Distributor datasheets, SDS, and product availability: https://www.henkel-adhesives.com/us/en/products/thermal-management.html

IPC-2221B: Generic Standard on Printed Board Design — Covers thermal management design rules including MCPCB: https://www.ipc.org/ipc-2221

IPC-4101E: Specification for Base Materials for Rigid and Multilayer Printed Boards — The qualification standard that covers IMS laminate materials: https://www.ipc.org/ipc-4101

ASTM D5470: Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulation Materials — The test method behind the thermal resistance values in the TDS: https://www.astm.org/d5470-17.html

Digikey HT-07006 Product Listing — Stock availability and pricing reference: https://www.digikey.com (search: “HT-07006 Bergquist”)

Frequently Asked Questions About Bergquist HT-07006

Q1: What is the difference between Bergquist HT-07006 and HT-04503?

Both HT-07006 and HT-04503 use the same dielectric chemistry (2.2 W/m-K, Tg 150°C, UL V-0) and are rated for the same maximum operating temperature of 140°C. The key difference is dielectric thickness: HT-04503 is 3 mil (76 µm) and HT-07006 is 6 mil (152 µm). The thicker dielectric in HT-07006 raises the AC breakdown voltage from 8.5 kVAC to 11 kVAC, providing more isolation headroom. The trade-off is higher thermal resistance — 0.71 °C·cm²/W versus 0.45 °C·cm²/W for HT-04503. If your application needs higher isolation voltage and can tolerate slightly higher thermal resistance, choose HT-07006. If thermal performance is the priority and your isolation requirement is met at 8.5 kVAC, choose HT-04503.

Q2: Is Bergquist HT-07006 compatible with lead-free soldering?

Yes, fully. The HT-07006 TDS confirms lead-free solder compatibility, with a solder limit rating of 325°C for 60 seconds (UL 796). Standard SAC305 lead-free reflow peaks at 245–260°C, well within this limit. The material is also RoHS compliant. Multiple reflow passes are possible, though as with any MCPCB material, minimizing thermal excursions beyond the rated limits will preserve long-term adhesion and dielectric integrity.

Q3: Can I design a multilayer PCB using Bergquist HT-07006?

HT-07006 is fundamentally a single-dielectric IMS construction — one copper circuit layer on one dielectric on one metal base. True multilayer stack-ups with multiple routing layers are available in the Thermal Clad family through the HT-09009 and dedicated multi-layer configurations. For most high-power applications where HT-07006 is appropriate, single-layer construction handles the circuit requirements because the power stage topology doesn’t require the routing density of a multilayer board. Where multilayer is genuinely needed, discuss the specific stack-up with your fabricator against the Bergquist multi-layer selection guide.

Q4: What base metal should I use with HT-07006 — aluminum or copper?

The answer depends on your thermal and mechanical requirements. Aluminum (5052 or 1100 alloy) is lighter, significantly cheaper, easier to machine, and easier to anodize for corrosion protection or cosmetic finish. Copper base offers higher base-metal thermal conductivity (~380 W/m-K vs. ~160 W/m-K for aluminum), which becomes meaningful in very high thermal load applications where spreading resistance in the base metal itself is a bottleneck. Copper is also preferred when you need to directly solder or braze the base metal to a heatsink, or when the board is part of a copper bus structure. For most LED, motor drive, and power supply applications, aluminum is the standard choice.

Q5: Where can I buy Bergquist HT-07006 laminate panels, and what’s the typical lead time?

HT-07006 panels are available through Henkel’s direct sales channel and authorized electronic components distributors including Digikey, Arrow, and Mouser. For PCBs fabricated on HT-07006 material, specialized MCPCB manufacturers maintain panel stock and can produce quick-turn prototypes. Standard fabricated board lead times from MCPCB-specialized shops typically run 5–10 business days for prototypes and 2–4 weeks for production quantities, though this varies by region and complexity. Always confirm material availability before committing to a design schedule, particularly for copper-base variants which are less commonly stocked.

Summary: Is Bergquist HT-07006 Right for Your Design?

The Bergquist HT-07006 earns its place in a design when three conditions converge: power density is high enough that standard FR4 thermal management is inadequate, the application requires electrical isolation above the 8.5 kVAC that the thinner HT-04503 provides, and the operating environment demands continuous reliability at temperatures up to 140°C. Those conditions are met frequently in solid-state relays, industrial motor drives, power conversion systems, high-reliability LED fixtures, and solar energy electronics.

It is not the right choice when you need maximum thermal performance at the lowest possible thermal resistance (choose HT-04503), when cost constraints favor a simpler laminate for a thermally mild application, or when your application demands higher temperature stability than the 150°C Tg can provide. In those edge cases, evaluating alternative MCPCB dielectrics or high-temperature laminate systems will serve you better.

For the majority of high-power IMS applications that land in the moderate-to-high power density range with meaningful isolation requirements, the HT-07006 is a well-characterized, widely available, UL-certified material with a long fabrication track record. The specifications are thoroughly documented, the fabrication ecosystem is mature, and the thermal performance is consistent. That combination makes it one of the most reliable material choices in the MCPCB toolkit.