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What Is Panasonic HEPER R-1755D: The High Heat Resistance (High-Tg) Multi-Layer Circuit Board Material?

The reliability as well as performance of a circuit board material is very necessary when choosing which material to use for your PCB needs. These features are part of those found in the properties of the Panasonic HEPER R-1755D material.

If you are seeking more information regarding the Panasonic HEPER R-1755D, then you are in the right place. This is because in this article, we will be revealing what it is, its properties, as well as the main features of this material.

Please continue reading as we widen your knowledge in this regard.

What is the Panasonic HEPER R-1755D?

The Panasonic HEPER R-1755D is a high reliability multilayer glass epoxy material. One great feature of this material is its low coefficient of thermal expansion as well as its high glass transition temperature.

These qualities alone are what engineers seek most when searching for the best possible material to meet their PCB needs. This Panasonic HEPER R-1755D is known as the laminate, while the prepreg is the R-1650D.

This material is majorly used for any automotive component. It has high reliability and high heat resistance. Let’s continue with this article as we discuss the properties of this material.

What are the Properties of the Panasonic HEPER R-1755D?

The following are the properties of the Panasonic HEPER R-1755D.

Glass Transition Temperature

With the DSC test method, the Panasonic HEPER R-1755D has a glass transition temperature of 163 degrees Celsius. While using the TMA and DMA test method, it has a value of 154 and 185. This property – glass transition temperature has to do with the temperature where the material turns amorphous when laminating under pressure and at a high temperature.

This temperature isn’t the maximum at which this PCB material operates, but the maximum at which it can endure within a short period before deteriorating.

Thermal decomposition

Using the TGA test method, the thermal decomposition of the Panasonic HEPER R-1755D is 345 degrees Celsius. This value for thermal decomposition indicates the temperature at which this material chemically decomposes. Here, this material loses about 5% of its mass weight. Furthermore, there’s usually an endothermic reaction for any thermal decomposition. This is due to the importance of heat in order to break this material’s chemical bonds.

Coefficient of Thermal Expansion

At the X and Y axis at α1, the Panasonic HEPER R-1755D has a CTE value of 10 – 12 ppm/℃ and 12 – 14 ppm/℃ respectively. Furthermore, at the Z-axis and α1, it has a CTE value of 43 ppm/℃, while at α2, its CTE is 236 degrees Celsius. The coefficient of thermal expansion indicates how much a material can expand when it is heated.

Dielectric Constant

The Panasonic HEPER R-1755D has a dielectric constant of 4.4 at 1 GHz. This property measures a material’s ability to store some electrical energy in a given electric field.

Dissipation Factor

The dissipation factor of the Panasonic HEPER R-1755D PCB material is 0.016 at 1 GHz. This value indicates the Panasonic HEPER R-1755D PCB material’s efficiency to act like an insulator. Furthermore, the Panasonic HEPER R-1755D PCB material has a low dissipation factor, which means that it is very efficient as an insulating material.

Water Absorption

The water absorption of the Panasonic HEPER R-1755D is 0.11%. This value is great being that when a PCB material absorbs water and moisture, it can lead to different failure mechanisms. When used in printed circuit boards it means it has the ability to prevent water or moisture from finding its way in, thereby causing the device to stop working.

Peel Strength

The peel strength of the Panasonic HEPER R-1755D is 1.3 kN/m. A material’s peel strength has to do with the material’s bond strength. To know the peel strength, a peel test is conducted. Here you pull the materials apart at a constant speed. Now, this average force necessary to pull this material apart is then used with the bond’s width measurement which determines the peel strength.

Delamination Time

The Panasonic HEPER R-1755D has a delamination time of 15 minutes. This is the time whereby the copper and resin, or reinforcement and resin separates or delaminates. These types of processes lead to defects in PCBs.

Flexural Modulus

The Panasonic HEPER R-1755D has a flexural modulus of 23 GPa for warp and 21 GPA for fill. Flexural modulus is a well-known physical property that denotes the ability for the Panasonic HEPER R-1755D to bend. Mechanically, we can explain further by saying it is the ratio of the stress to the strain when bending or flexural deformation is going on. This is equivalent to a material’s elastic modulus.


Another property is flammability and the Panasonic HEPER R-1755D has a rating of 94 V-0. This means the material has been well-tested to ensure that burning will have to stop within ten seconds.

Main Features of the Panasonic HEPER R-1755D Material

The following are the main features of the Panasonic HEPER R-1755D material

  • Its heat resistance is high with a glass transition temperature of 163 degrees Celsius.
  • When used in harsh environments, this material possesses great through-hole reliability and excellent reliability.
  • Furthermore, it works well with great laminate processability and lead-free soldering.

Factors you should Consider when Choosing the Panasonic HEPER R-1755D material


The first question you should ask yourself is if the platform is suitable for what you intend to use it for. This is to ensure that you get the best results.

Temperature management

Check out the temperature performance of a PCB material before you decide to choose it. Also, you must note the amount of change that the dielectric constant of this material experiences with temperature.

Operational environment

When we talk of an operational environment, we mean moisture and temperature. Be sure that the PCB material you wish to use can work under any extreme industrial environment.


By now, you should know why the Panasonic HEPER R-1755D is highly regarded. It has great properties, which includes its high glass transition temperature and low coefficient of thermal expansion.