New thermal management material made of polyimide resin

Dr. Dietrich Müller GmbH, a leading supplier of electrical insulation materials, thermal interface materials, gaskets, and technical films, has expanded its product range with a polyimide paper that sets new standards. Polyimides (PI) are high-performance plastics and are even used in aerospace. Polyimide paper finds diverse applications in electrical engineering and electronics due to its heat resistance, low outgassing, radiation resistance, and insulating properties. The new thermal management material offers several advantages, such as high heat resistance, light weight, and the typical properties of polyimide paper.

Properties of polyamide paper

The following nine properties of polyimide paper should be known to developers when considering its use:

• in discs available in various diameters
• Density: 0,2 g/cm³
• Thermal conductivity: 0,03 W/mK
• Air permeability: 200 cc/m²/sec
• Tensile strength: 15 MPa
• Elongation: 2%
• Elastic modulus: 0,8 GPa
• Coefficient of thermal expansion: 30 ppm/°C
• Breakdown voltage 15 kV/mm

The material has the following outgassing data:

• Total mass loss (TML) in %: 0,705 ±0,015
• Collected volatile condensable substances (CVCM) in %: 0,001 ±0,000
• Water vapor recovery (WVR) in %: 0,568 ±0,008

Figures 1 and 2 below illustrate the thermal conductivity and the thermogravimetric analysis:

Fig. 1: Thermal conductivity in W/m*K	Fig. 2: Thermogravimetric Analysis

Polyimide paper in various configurations

Polyimide paper can be manufactured in various configurations. The material can be combined with different additional layers, such as polyimide film, aluminum, or graphite. Multilayer arrangements and 3D mold construction are also possible. Table 1 below illustrates the various configuration options.

The Brand		Features
Heat barrier tape		Polyimide paper does not contain silicon dioxide powder to enable an adhesive coating.
PI film lamination		Thermal barrier material. Waterproof, increased tear resistance, electrical insulation.
Aluminum vapor deposition		Radiant heat & conductive thermal barrier
Graphite lamination		Heat spreading and heat barrier to increase heat dissipation efficiency
Multilayer (<1mm thick)		Various polyimide structures
3D mold making		Placing molded parts (thickness >0,7mm)
Table 1: Configuration options for polyimide paper

Applications of polyimide paper

Whether as adhesive-coated heat barrier tape, aluminized polyimide paper, polyimide paper sheet (multi-layer), layer construction or 3D mold making, the application range of polyimide paper is broad and versatile.

Adhesive-coated heat barrier tape	Aluminized polyimide paper	Polyimide paperboard (multilayer)	Layer construction, 3D mold making
Table 2: Applications of polyimide paper

Furthermore, polyimide paper can be ideally combined with CFRP applications. This allows for heat protection applications or circuits within the structure (polyimide paper for impedance control).

Heat protection for CFRP	Circuit in structure	Circuit in structure
Table 3: Combined technology with CFRP

From the project sketch through processing to the finished serial part made of polyimide paper

As part of its product design services, Dr. Dietrich Müller GmbH offers a wide range of options and ideas to achieve improved production processes and optimal product quality. Various manufacturing processes are available for processing polyimide paper, such as cutting, die-cutting, forming, laminating, and gluing. Experienced application engineers and production specialists at Dr. Dietrich Müller GmbH are available to assist with the implementation of specific applications using polyimide paper.

In the area of ​​prototype production, the company has state-of-the-art laser cutting machines, knife cutting machines, and waterjet cutting technology at its disposal. Furthermore, initial samples can also be produced on the CNC machining centers.

Dr. Dietrich Müller GmbH is the specialist for electrical insulating materials, thermal conductivity products, seals and technical films.

In the area of ​​series production for the manufacture of stamped parts from polyimide paper, state-of-the-art stamping machines, rotary stamping machines, eccentric presses and hand stampers are used.

Dr. Dietrich Müller GmbH specializes in the production of polyimide paper, electrical insulating materials, thermal conductivity products, gaskets, and technical films. The product portfolio includes flexible electrical insulating materials, prepregs, coated fabrics, adhesive tapes, laminates and profiles, thermal conductivity products, technical films, sealing materials, mica products, and other product groups.

The execution of orders utilizes both materials from third-party suppliers and the company's own patented solutions. In addition to its own products, the company also offers technical services and consulting.