The complete engineer’s guide to Bergquist Thermal Clad PCB materials — dielectric series comparison, design rules, thermal specs, FAQs, and official datasheet links for 2025.

If you’ve spent any time specifying materials for high-power LED drivers, motor control boards, or automotive power modules, you’ve almost certainly landed on Bergquist Thermal Clad PCB as a candidate material. It shows up in the datasheet for half the metal-core substrates on the market, and with good reason — the dielectric technology behind it has been setting the benchmark for insulated metal substrates (IMS) for decades.

This guide breaks down everything a working PCB engineer needs to know: the dielectric series, real-world thermal numbers, design rules, fabrication gotchas, and when Thermal Clad genuinely outperforms the competition versus when a cheaper alternative will do the job just fine.

What Is Bergquist Thermal Clad PCB?

Bergquist Thermal Clad is a metal-core PCB (MCPCB) substrate technology developed by The Bergquist Company, now operating under Henkel Corporation’s Electronic Materials division and also carried by successor brands such as TCLAD Inc. At its core — literally — the product is a laminate stack: a copper circuit foil bonded through a proprietary thermally conductive dielectric layer to an aluminum or copper baseplate.

What makes it different from generic aluminum-base PCBs is that dielectric. The technology of Thermal Clad resides in the dielectric layer — it is the key element for optimizing performance. The dielectric is a proprietary polymer/ceramic blend that gives Thermal Clad its excellent electrical isolation properties and low thermal impedance. The polymer is chosen for its electrical isolation properties, ability to resist thermal aging and high bond strengths. The ceramic filler enhances thermal conductivity and maintains high dielectric strength — resulting in a layer of isolation that can maintain these properties even at 0.003″ (76µm) thickness.

In other words, competing MCPCB products often use standard prepreg as the dielectric. Other manufacturers use standard prepreg as the dielectric layer, but prepreg doesn’t provide the high thermal conductivity and resulting thermal performance required to help assure the lowest possible operating temperatures and brightest light output for high-intensity LEDs. That’s the core value proposition in a single sentence.

The Three-Layer Structure

Every Bergquist Thermal Clad board follows a consistent build:

Layer	Material Options	Typical Thickness
Circuit Layer (Top)	1 oz, 2 oz, 3 oz copper foil	35 µm – 105 µm
Dielectric Layer	Proprietary polymer/ceramic blend (HPL, HT, MP, LM)	38 µm – 254 µm
Base Metal (Core)	Aluminum (1000/3000/5000/6000 series) or Copper	0.8 mm – 3.2 mm

The base metal is where the heat ultimately goes. Copper gives you better conductivity (390 W/mK), but aluminum is far more cost-effective at 205 W/mK and handles the thermal load in the overwhelming majority of commercial applications.

The Four Bergquist Thermal Clad Dielectric Series

This is the most important section for any engineer spec’ing a board. Thermal Clad circuit board materials are available from The Bergquist Company in four different thermal conductivities: High Power Lighting (HPL), High Temperature (HT), Low Modulus (LM), and Multi-Purpose (MP). Each is engineered for a specific operating envelope.

HPL — High Power Lighting

HPL is the go-to dielectric for demanding LED applications. HPL is a dielectric specifically formulated for high power lighting LED applications with demanding thermal performance requirements. This thin dielectric at 0.0015″ (38µm) has an ability to withstand high temperatures with a glass transition of 185°C and phenomenal thermal performance of 0.30°C/W.

The part number most commonly seen in the field is HPL-03015, which refers to the 0.030″ (0.76mm) base aluminum thickness with 1 oz (35µm) copper. Bergquist Thermal Clad Metal Core PCBs minimize thermal impedance and conduct heat more effectively and efficiently than standard printed wiring boards.

When to use HPL: Any design where junction temperature is the dominant constraint — high-wattage COB LEDs, stadium lighting, projector systems, and backlit display modules.

HT — High Temperature

The HT series offers a balance of elevated operating temperature tolerance and strong thermal conductivity. The HT-04503 provides high thermal conductivity of 4.1 W/m-K for high temperature applications, is lead-free solder compatible, Eutectic AuSn compatible, RoHS compliant and environmentally green, and available on all aluminum and copper metal substrates.

The HT-07006 variant steps up the dielectric thickness to 0.006″ (152µm) while maintaining that same 4.1 W/mK conductivity, making it the right call when you need more electrical isolation — say, above 480V AC systems. The HT-07006 features a very low thermal resistance of 0.71°C-cm²/W combined with high thermal conductivity of 4.1 W/m-K, and the product is certified RoHS compliant.

When to use HT: Power conversion, motor drives, inverters, and any system needing eutectic gold-tin solder compatibility or operation above 150°C continuous.

MP — Multi-Purpose

MP-06503 is the workhorse of the Thermal Clad lineup — a cost-optimized general-purpose substrate covering a huge range of mid-power applications. With a thermal resistance of 0.58°C-cm²/W, MP-06503 provides efficient heat dissipation, ensuring optimal thermal management for electronic devices. It exhibits a thermal conductivity of 2.4 W/m-K, enabling efficient heat transfer across the PCB.

The technology of Thermal Clad resides in the dielectric. Optimal storage for the MP-06503 is 5 to 25°C for a 12-month shelf life. Worth noting for anyone managing incoming materials.

When to use MP: Solid-state relays, power supplies, battery management modules, and mid-power LED modules where budget pressure is real but you still need something better than off-brand MCPCB stock.

LM — Low Modulus

LM is a less commonly discussed variant but worth knowing. The lower modulus dielectric provides improved mechanical compliance, which matters when you have CTE mismatch concerns between a large component and the substrate. This is especially relevant in applications with severe thermal cycling, where a brittle dielectric can delaminate over time.

When to use LM: Automotive underhood applications, aerospace modules, or any design where the assembly will see hundreds of thermal cycles between cold soak and operating temperature.

Bergquist Thermal Clad Dielectric Quick-Reference Table

Series	Thermal Conductivity	Thermal Resistance	Dielectric Thickness	Key Application
HPL	~3.0 W/mK	0.30°C-cm²/W	38 µm (0.0015″)	High-power LED, backlight
HT-04503	4.1 W/mK	0.50°C-cm²/W	102 µm (0.004″)	High-temp, motor drives
HT-07006	4.1 W/mK	0.71°C-cm²/W	152 µm (0.006″)	>480V isolation, inverters
MP-06503	2.4 W/mK	0.58°C-cm²/W	152 µm (0.006″)	General-purpose, PSU
LM	~2.0 W/mK	~0.80°C-cm²/W	203 µm (0.008″)	High-cycle automotive

Values are nominal. Always verify against the specific product datasheet for your revision.

Bergquist Thermal Clad vs. FR-4 vs. Generic MCPCB

One of the most common engineering questions is: “Do I actually need Thermal Clad, or will a cheaper metal-core board do the job?” The answer depends entirely on your thermal budget.

Bergquist Thermal Clad Metal Core PCBs minimize thermal impedance and conduct heat more effectively and efficiently than standard printed wiring boards. The low thermal impedance of Thermal Clad dielectrics outperforms other PCB materials and offers a cost-effective solution eliminating additional LEDs for simplified designs and an overall less complicated production process.

Here’s how the materials stack up for a typical 40W power stage application:

Parameter	FR-4 (1.6mm)	Generic MCPCB	Bergquist Thermal Clad HT	Bergquist Thermal Clad HPL
Thermal Conductivity	0.3 W/mK	1.0–2.0 W/mK	4.1 W/mK	~3.0 W/mK
Dielectric Thickness	200 µm+	100–150 µm	102–152 µm	38 µm
Max Continuous Temp	130°C (Tg)	~130°C	150°C+	185°C Tg
Lead-Free Solder	Yes	Yes	Yes	Yes
IPC / UL Certification	IPC-4101	Varies	UL, ISO 9001	UL, ISO 9001
Relative Cost	Low	Medium	Medium-High	High

The numbers tell the story. If you’re running a 5W LED module, a decent generic MCPCB is probably sufficient. At 20W and beyond — particularly if junction temperature headroom is tight — the thermal conductivity gap between Bergquist and generic alternatives starts translating directly into either shorter LED lifespan or the need for a larger heatsink.

Thermal Clad can replace large-area ceramic substrates. It can also be used as a mechanically durable support for ceramic spacers or direct bonded copper subassemblies. The copper circuit layer of Thermal Clad has more current carrying capability than thick-film ceramic technology.

This makes Thermal Clad a direct substitute for DBC (Direct Bonded Copper) ceramics in moderate-power applications — at a significantly lower fabrication cost.

Key Applications of Bergquist Thermal Clad PCB

LED Lighting — The Primary Use Case

LED lighting has truly transformed how we light up our spaces, offering energy-efficient alternatives that stand the test of time. But as LEDs get more powerful and brighter, managing heat becomes a bigger concern. That’s where Bergquist Thermal Clad PCBs come in, providing the perfect fix for LED lighting designs.

The HPL dielectric series was specifically engineered for this market. Bergquist provides critical thermal management support for a myriad of power LED applications including medical, signage, signal, transportation, aircraft, automotive, security, portable, theatrical, commercial, residential, and street lighting applications.

For a street lighting or high-bay LED array running at 100W+, the thermal budget is unforgiving. Using HPL with a direct thermal path from LED emitter to aluminum heatsink — with no thermal grease or TIM interface — delivers measurably lower Tj compared to any standard FR-4 or generic MCPCB solution.

Automotive and EV Power Electronics

The automotive industry has seen a substantial shift toward electric vehicles (EVs) and advanced driver-assistance systems (ADAS). These systems demand reliable electronic components that can withstand extreme environments, including fluctuating temperatures and vibrations. Bergquist PCBs meet these challenges with their high thermal conductivity, reliability, and rugged construction. Bergquist PCBs are designed to handle components like inverters, battery management systems (BMS), and electronic control units (ECUs) with ease.

Underhood environments routinely see ambient temperatures above 100°C combined with aggressive vibration profiles. The HT and LM series both address this — HT for raw thermal performance, LM where fatigue life under thermal cycling is the constraint.

Power Conversion and Motor Drives

Bergquist thermal clad is a preferred choice for engineers for power conversion due to its watt-density and size. Motor drives are also ideal for Bergquist thermal clad — they are good dielectric material and feature high watt density, enabling fabrication and installation of compact form factors into motor drives.

Switching power supplies, VFDs, and servo drives all pack high-current components (IGBTs, MOSFETs, diode bridges) into tight footprints. Thermal Clad eliminates the need for individual TO-220 or TO-247 insulators (mica, Kapton, silicone pads) under power devices — the board itself provides the isolation, and the assembly simplification is real.

Industrial and Aerospace

TCLAD Insulated Metal Substrate (IMS) PCBs deliver high efficiency, exceptional durability, and long-term reliability for mission-critical electronics operating in the extreme conditions of aerospace and defense applications.

In harsh-environment applications, the UL certification and controlled manufacturing processes of Bergquist materials are often a procurement requirement, not just a nice-to-have.

Design Guide for Bergquist Thermal Clad PCB

Getting the most out of Thermal Clad starts at the design stage, not at the FAI.

Dielectric Selection and Thermal Budget

Before you pick a dielectric grade, run the numbers. The thermal path from component junction to ambient is a series of resistances. The Thermal Clad layer is just one of them. Your calculation should include:

1. Junction-to-case resistance of the component (Rθjc from datasheet)
2. Solder joint resistance (typically 0.1–0.5°C/W for SMD)
3. Thermal Clad dielectric resistance (from the product spec)
4. Base metal spreading resistance
5. Thermal interface to heatsink (if applicable)
6. Heatsink-to-ambient (Rθsa)

If your calculation shows Tj is within 10°C of the component’s maximum at full load, you need either a lower-resistance dielectric (HPL vs. HT) or a thicker copper circuit layer.

Copper Circuit Layer Thickness

The copper circuit layer of Thermal Clad has more current carrying capability than thick-film ceramic technology. However, trace width still matters. The circuit layer is the component-mounting layer in Thermal Clad. Current carrying capability is a key consideration because this layer typically serves as a printed circuit, interconnecting the components of the assembly. On Thermal Clad, smaller lines will not overheat, but they will increase the waste thermal heat of the assembly.

Use 2 oz or 3 oz copper (70µm or 105µm) for power traces wherever possible. On Thermal Clad, the heat generated by I²R losses in copper traces conducts straight down through the dielectric — which is a feature, not a bug.

Dielectric Thickness and Voltage Isolation

The relationship between dielectric thickness and working voltage is non-linear. For applications with an expected voltage over 480 Volts AC, Bergquist recommends a dielectric thickness greater than 0.003″ (76µm). This immediately rules out HPL (38µm) for mains-connected power stages above that threshold — HT-04503 or HT-07006 becomes the correct choice.

Thermal Via and Copper Pour Strategy

Unlike multilayer FR-4 PCBs where thermal vias punch heat down through the board, Thermal Clad does not support plated through-holes in the traditional sense. The base metal is electrically isolated by the dielectric. What you can do:

• Use large copper pours on the circuit layer directly beneath high-power components to spread heat laterally before it enters the dielectric
• Implement selective dielectric removal (SDR) processes — where the dielectric is locally removed to create direct copper-to-baseplate contact for critical die-attach applications. Bergquist has developed a process for selectively removing dielectric to expose the baseplate, which is used in advanced power module assembly.

Design Rule Quick Reference

Parameter	Recommended Minimum
Conductor to board edge	0.5 mm
Conductor to conductor (signal)	0.15 mm
Conductor to conductor (power)	Per IPC-2221 spacing table
Non-plated drilled hole (min)	0.76 mm (0.030″)
Drilled/plated via hole (min)	0.25 mm (0.010″)
Solder mask registration	±0.1 mm
Edge connector chamfer	45° recommended

Fabrication and Assembly Considerations

Drilling and Routing

Aluminum-base Thermal Clad machines differently from FR-4. Drill bits designed for FR-4 will work but wear faster. For production runs, use carbide bits specified for aluminum composite materials. Routing should use single-flute upcut bits to avoid aluminum galling on the tool. Punching is viable for simple shapes but requires careful die design — the ceramic-filled dielectric can crack if punch clearance is excessive.

Solder Mask and Surface Finish

Standard liquid photoimageable (LPI) solder mask applies to Thermal Clad circuit layers without process modification. Surface finish options are similar to standard PCBs:

Surface Finish	Suitability for Thermal Clad	Notes
HASL (lead-free)	Good	Standard choice for most applications
ENIG	Excellent	Preferred for fine-pitch SMD and wire bonding
Immersion Silver	Good	Cost-effective alternative to ENIG
OSP	Limited	Short shelf life; avoid for high-reliability
Eutectic AuSn	HT series only	Confirmed compatible per datasheet

Reflow Soldering

Standard SMT reflow profiles work on Thermal Clad. The aluminum base actually helps here — its thermal mass smooths out temperature ramp rates across the board. Be aware that: (a) the high thermal conductivity means large heat sinks or ground pours may require profiling adjustment, and (b) component leads or packages with high CTE mismatch relative to aluminum can stress solder joints under thermal cycling. For critical reliability, validate your solder joint fatigue life with FEA if the board will see >1000 thermal cycles.

Wire Bonding and Direct Die Attachment

The HT dielectrics are UL solder rated at 325°C/60 seconds, enabling Eutectic Gold/Tin solders — which opens the door to direct die-attach processes used in power module assembly. Wire bonding is supported on appropriately finished pads. Wire bonding is a connection technique that utilizes the surface mount ability of a PCB. In thermal clad assembly, pin headers and pin connectors are very useful when attaching an FR-4 panel to a thermal clad assembly.

Bergquist Thermal Clad vs. Arlon PCB Materials

When evaluating high-performance PCB substrate families, engineers often compare Bergquist Thermal Clad against other specialty laminates. Arlon PCB materials — particularly the AD/CLTE series — occupy a different part of the design space: they target high-frequency RF and microwave applications rather than thermal management. If your design requires both RF performance and thermal management (say, a high-power amplifier module), you may end up using Arlon-class materials for the RF section and Thermal Clad for the power stage section within the same assembly.

The comparison table below covers the most common design scenarios:

Criteria	Bergquist Thermal Clad	Arlon AD-Series	Standard FR-4
Primary strength	Thermal management	RF/Microwave performance	General-purpose cost
Thermal conductivity	2.4–4.1 W/mK	0.3–0.7 W/mK	~0.3 W/mK
Dielectric constant (Dk)	~4.5–5.5	3.0–10.2 (wide range)	4.5
Loss tangent (Df)	~0.01–0.02	0.0009–0.002 (low loss)	~0.02
Base substrate	Metal (Al or Cu)	PTFE/ceramic or thermoset	Glass-epoxy
Ideal application	LED, power electronics, motor drives	RF amplifiers, antennas, radar	General electronics

Neither material is universally superior — they solve different problems. Knowing when to reach for each is the mark of an experienced designer.

Where to Source Bergquist Thermal Clad Materials and PCBs

Raw Material Distributors (Panel Stock)

If you’re qualifying the material yourself or sending it to a contract manufacturer, the following sources stock Bergquist Thermal Clad laminates:

Distributor	Region	Link
Digi-Key Electronics	Global	digikey.com
Mouser Electronics	Global	mouser.com
Arrow Electronics	Global	arrow.com
Henkel / Bergquist Direct	Global	henkel.com
TCLAD Inc.	US / Europe / Asia	tclad.com

Useful Technical Resources and Datasheets

Below is a curated list of official and reference documents that should be bookmarked by any engineer working with Bergquist Thermal Clad PCB:

Resource	Description	Link
Thermal Clad Selection Guide	Complete dielectric selection, design rules, and assembly guidelines	Digi-Key PDF
HPL-03015 Datasheet	Technical data for the High Power Lighting dielectric	mclpcb.com PDF
HT-04503 Datasheet	High Temperature 4.1 W/mK dielectric data	mclpcb.com PDF
HT-07006 Datasheet	High Temperature, 0.006″ thick dielectric	mclpcb.com PDF
MP-06503 Datasheet	Multi-Purpose dielectric data	mclpcb.com PDF
IPC-2221	Generic Standard for Printed Board Design (for trace/spacing rules)	IPC.org
IPC-4562	Copper foil specification (relevant for circuit layer thickness)	IPC.org
LED Thermal Solutions Guide	Bergquist application guide for LED thermal management	Henkel-dam PDF

Pros and Cons of Bergquist Thermal Clad PCB

No material is perfect. Here is an engineer’s honest assessment:

Advantages

Bergquist thermal clad PCBs feature low thermal impedance which outperforms other insulators, allowing cooler operation. These thermal clad PCBs increase the level of durability because designs are simple and components run cool. The thermal clad removes the thermal interface and uses thermal solder joints, making assemblies run cooler. These thermal clad PCBs allow automated pick-and-place for SMDs, which minimizes production costs. Bergquist thermal clad minimizes board space and replaces other components like heat sinks, and helps eliminate rubber or mica insulators under power devices.

In practical terms this means: fewer BoM lines (no individual component TIMs), simplified assembly (no hardware-torqued insulators), and PCB-level thermal management that scales cleanly from prototype to production.

Disadvantages and Limitations

• Cost: Panel stock is significantly more expensive than FR-4, and fabrication costs are higher due to specialized tooling and process parameters.
• No plated through-holes to the baseplate: You cannot create a conventional electrical via to the base metal. All electrical routing is on the circuit side, which limits you to single-layer or specially configured two-layer constructions.
• Dielectric thickness limitation on voltage rating: HPL’s ultra-thin dielectric limits isolation voltage — it is not suitable for line-voltage isolation on its own at high power levels.
• Panelization and singulation: V-scoring works but requires controlled depth. CNC routing with appropriate tooling is preferred for clean edges.
• Heavier than FR-4 equivalents: The aluminum base adds weight — a consideration in portable, wearable, or aviation-certified applications.

Common Mistakes Engineers Make with Bergquist Thermal Clad PCB

Based on the types of failures that show up in field returns and DFM reviews, these are the problems worth specifically avoiding:

1. Treating it like FR-4 in the Gerber package. Thermal Clad requires specific fabrication notes: base metal type and thickness, dielectric grade, copper weight, surface finish, and any selective dielectric removal areas. A generic FR-4 fab note set will result in the wrong board.

2. Ignoring the CTE mismatch between large SMD components and the aluminum base. Aluminum has a CTE of approximately 23 ppm/°C; ceramic capacitors and large IC packages are typically 6–10 ppm/°C. Large ceramic caps (2220 size and above) mounted on aluminum MCPCB boards are fatigue-failure candidates in thermal-cycling applications. Size down, use polymer caps, or add strain relief in the layout.

3. Using HPL for designs above 480V. The 38µm dielectric is not appropriate for high-voltage isolation. Refer to IEC 60664-1 for full creepage and clearance requirements and select HT-04503 or HT-07006 accordingly.

4. Forgetting that the base metal is thermally — but not always electrically — isolated. Some designs unintentionally create a ground connection to the chassis through the mounting hardware. If your base metal must be floating, use insulated standoffs.

5. Over-tightening assembly screws. Aluminum is softer than steel. Use torque specs from your hardware supplier and avoid steel screws without proper thread inserts in the board.

FAQs About Bergquist Thermal Clad PCB

Q1: What is the difference between Bergquist Thermal Clad and a standard aluminum PCB?

The defining difference is the dielectric layer. A standard aluminum-base PCB uses conventional epoxy prepreg (similar to FR-4) as the insulating layer between the circuit copper and the aluminum core. Bergquist Thermal Clad uses a proprietary polymer/ceramic compound that delivers 4–10× the thermal conductivity of standard prepreg. This translates directly into lower component operating temperatures for the same power dissipation level, or smaller/lighter board solutions for the same thermal budget.

Q2: Can Bergquist Thermal Clad PCB be used in multilayer designs?

Yes, with some caveats. Bergquist thermal clads aren’t only incorporated with metal base layers — these substrates can boost their function by replacing FR-4 in multilayer assemblies. A common two-layer configuration bonds a standard FR-4 or Thermal Clad circuit to the back of the Thermal Clad base using Bond-Ply adhesive. This gives you two routing layers while maintaining the metal-base thermal path. True buried via multilayer constructions are not standard for Thermal Clad.

Q3: Is Bergquist Thermal Clad RoHS and REACH compliant?

Yes. The HT series is RoHS compliant and environmentally green. The same applies across the HPL and MP families. All current Bergquist Thermal Clad products are lead-free solder process compatible and meet the material restriction requirements of RoHS 2 and REACH. Always request a current compliance declaration from your supplier, as formulations can be updated.

Q4: How does Bergquist Thermal Clad perform in thermal cycling tests?

Thermal Clad substrates are well-characterized for reliability. Bergquist PCBs are designed to handle the demands of electric vehicles or industrial machines, including fluctuating temperatures and vibrations. Bergquist PCBs meet these challenges with their high thermal conductivity, reliability, and rugged construction. For the most demanding thermal cycling requirements (e.g., AEC-Q200 automotive qualification), the LM (Low Modulus) dielectric variant is specifically formulated for improved fatigue resistance. For typical commercial or industrial applications (−40°C to +85°C, ~500 cycles), standard HT or MP materials perform well without special consideration.

Q5: Who makes Bergquist Thermal Clad PCBs now, and is it the same product?

The Bergquist Company was acquired by Henkel Corporation and integrated into their Electronic Materials division. The Bergquist TCLAD products are now manufactured and supplied through Henkel Corporation. TCLAD Inc. is a separate company that has developed its own IMS technology continuing in the same product space. The core dielectric technology principles remain consistent, but engineers specifying Bergquist materials by name should request the Henkel Bergquist branded product or verify equivalency testing if substituting a TCLAD Inc. product. The part number naming convention (HPL-03015, HT-04503, etc.) has been preserved through the Henkel era.

Final Thoughts

Bergquist Thermal Clad PCB has earned its reputation by solving a real engineering problem — getting heat out of dense, high-power electronics — with a material that is manufacturable at scale, certifiable for safety agencies, and well-understood by the PCB supply chain. The four dielectric families (HPL, HT, MP, LM) give engineers enough granularity to optimize for cost, thermal performance, or mechanical robustness depending on the application.

The real skill is knowing when to reach for it. For a 3W LED nightlight, it is overkill. For a 150W EV charging module expected to survive 10 years and 2,000 thermal cycles, it is the right tool. Getting that judgment right — and then executing the design with the correct grade, copper weight, and assembly process — is what separates a board that runs cool and reliable from one that comes back in a warranty claim.

Use the datasheets and design guides linked above, run the thermal resistance calculations, and remember that the dielectric grade selection is one of the most leverage-heavy decisions in the entire design. Get that right, and the rest tends to follow.

Have a design challenge with Bergquist Thermal Clad PCB materials? Drop your questions in the comments or reach out to a qualified PCB manufacturer who can help with material selection and DFM review.