Hi-Flow® 300P / THF 1600P Polyimide Phase-Change Material

Introduction: Why Phase-Change TIMs Matter

In modern power electronics, managing heat between components like MOSFETs, IGBTs, and modules is critical. Poor thermal transfer raises junction temperatures, reduces reliability, and limits performance.

Phase-change thermal interface materials (TIMs) have become a leading solution because they combine:

• Low thermal impedance for efficient heat transfer

• Mechanical compliance to fill surface imperfections

• Electrical insulation for safety and versatility

• Ease of handling and assembly for manufacturing

Among these, BERGQUIST® Hi-Flow THF 1600P (Hi-Flow 300P) stands out. It merges a thermally conductive phase-change compound with a polyimide reinforcement film, providing both electrical isolation and excellent heat conduction.

Material Description

Hi-Flow THF 1600P (HF300P) is an electrically insulating, thermally conductive phase-change film that incorporates a thin polyimide carrier.
This design gives the material mechanical strength and dielectric protection, while the phase-change layer softens at approximately 55 °C, conforming to surface irregularities once the assembly heats up.

The pad is supplied on a release liner for easy placement in automated or manual processes. Once in use, it transitions from a dry, solid state to a wax-like, conformal interface—improving heat flow without the mess of traditional greases. 

Key Properties

The polyimide reinforcement gives the pad mechanical stability and handling strength, while maintaining excellent dielectric insulation. When the device reaches operating temperature, the softened phase-change layer fills micro-voids and eliminates air gaps for optimal heat transfer. This material is thin. Remember, think THIN to WIN.

Advantages

• Clean application – no pump-out or migration like thermal grease

• Dielectric strength – reliable isolation up to several kilovolts

• Reworkable – solid at room temperature for easy replacement

• Durable – resists cut-through and maintains performance during thermal cycling

• Production-friendly – supplied in sheet or die-cut form with release liners

Design & Assembly Tips

1. Pressure consistency: Use clips or springs to maintain pressure after the phase-change layer softens.

2. Optimal thickness: Select the thinnest version that accommodates surface roughness.

3. Clean surfaces: Always clean mating surfaces before application for maximum performance.

4. Temperature control: Avoid exceeding 150 °C for long periods to preserve dielectric integrity.

5. Storage: Store below 40 °C to prevent pre-softening.

Applications

Hi-Flow THF 1600P is ideal for:

• Power transistors and rectifiers

• IGBT modules and converters

• Automotive and industrial control electronics

• Telecom and power-supply assemblies

• Any situation requiring electrical isolation with strong thermal transfer

Its polyimide reinforcement makes it particularly well-suited for spring-clamped assemblies or modules under vibration, where a combination of strength and compliance is essential.

Comparison to Alternatives

Compared to traditional thermal greases or adhesives:

• Cleaner and easier to assemble

• No cure time or outgassing

• Better long-term reliability under cycling and rework conditions

Compared to soft silicone pads:

• Higher dielectric strength

• Lower initial impedance

• Superior thin-film conformity once heated to correct contact/thickness.

Nomenclature to Keep In Mind for Print Callouts:

HF300P-0.001-00-1112 (.001” thickness)

HF300P-0.0015-00-1112 (.0015” thickness)

HF300P-0.002-00-1112 (.002” thickness)

Summary

BERGQUIST® Hi-Flow THF 1600P / 300P is a balanced, high-performance phase-change thermal interface material combining:

• The thermal conductivity of a filled wax-like compound,

• The mechanical strength of a polyimide carrier,

• And the clean handling expected in modern manufacturing.

It’s an excellent choice when engineers need both electrical isolation and low thermal resistance without sacrificing manufacturability or reliability. NEDC does custom die cutting for customers.