## What is the thermal conductivity of fr4?

0.25 W / m-K
FR-4 has a poor thermal conductivity of 0.25 W / m-K; the thermal insulance factor of a 0.7-mm FR-4 layer is 2040°C-mm2 / W.

## How do you calculate specific thermal resistance?

The units for thermal resistance are Kelvins per watts (K/W). By definition, thermal resistance R is the ratio of the temperature difference T2 – T1 and the heat flow Q1-2 between two points. The thermal resistance formula is the following: R = (T2 – T1) / Q.

What is TC thermal?

SightSensor TC Thermal Camera. The SightSensor TC is a dual-imager smart camera that combines the power of thermal detection with the power of visible color to detect targets with exceptional reliability over large perimeters.

How many thermal resistance are there?

The SI unit of absolute thermal resistance is kelvins per watt (K/W) or the equivalent degrees Celsius per watt (°C/W) – the two are the same since the intervals are equal: ΔT = 1 K = 1 °C.

### What is Class 11 thermal conductivity?

Thermal conductivity refers to the ability of a given material to conduct/transfer heat. It is generally denoted by the symbol ‘k’ but can also be denoted by ‘λ’ and ‘κ’. The reciprocal of this quantity is known as thermal resistivity.

### What is the highest thermal resistance material?

hafnium carbide
Researchers have discovered that tantalum carbide and hafnium carbide materials can withstand scorching temperatures of nearly 4000 degrees Celsius. In particular, the team from Imperial College London discovered that the melting point of hafnium carbide is the highest ever recorded for a material.

What is thermal resistance R value?

The thermal resistance (R-value) is the reciprocal of l (1/l) and is used for calculating the thermal resistance of any material or composite material. The R-value can be defined in simple terms as the resistance that any specific material offers to the heat flow. A good insulation material will have a high R-value.

What is coefficient of thermal conductivity?

Coefficient of thermal conductivity of a material is defined as the quantity of heat conducted per second through a unit area of a slab of unit thickness when the temperature difference between its ends is 1K.

## What temperature can FR4 withstand?

Typically, FR4 PCB is rated to have a Tg of 130°C. In other words, if a PCB rated at 130°C is heated beyond its glass transition temperature, it loses its solid form.

## At what temperature does FR4 burn?

Materials for printed circuit boards

Type Description Glass transient temp. Tg
FR4 halogen free This laminate type does not contain halogen, antimony, phosphorus, etc., does not emit hazardous substances when burning. 140°C
FR4 High Tg, FR5 These laminate types have excellent performance in Pb-free soldering. 170°C

How strong is FR4?

45,000 PSI
As we’ve written in this blog before, FR-4 rivals the strength of some metals. The Ultimate Tensile Strength (UTI) of FR-4 is 45,000 PSI while the UTI of cast iron is 29,000 PSI. Copper comes in at 31,900 PSI and aluminum is 43,500 PSI.

What is the FR4 thermal resistance of a PCB?

FR4 thermal resistance depends on its thermal conductivity. FR4 conductivity enables the transfer of heat from a warmer area to a cooler area at a quicker rate. Hence, the PCB will have a lower thermal resistance. The various components and parts on a circuit board contribute to thermal conductivity.

### What is the thermal insulance factor of FR4?

• Thermal vias play a critical role in reducing the thermal resistance of PCBs, especially FR-4. FR-4 has a poor thermal conductivity of 0.25 W / m-K; the thermal insulance factor of a 0.7-mm FR-4 layer is 2040°C-mm2/ W.

### What is the operating temperature limit of low Tg FR4?

For example, a low Tg FR4 of 130°C should have an operating temperature limit of 110°C. As PCB designers, you’ll need to be aware of thermal regulation techniques in the design. Power regulation modules emit heat and proper dissipation techniques should be applied.

Is FR4 a good fire resistance?

FR-4 also offers a good ratio between fire resistance and weight. FR-4 High CTI: The Comparative Tracking Index (tracking resistance) is over 600 volts. FR-4 without copper foil: Ideally suited for insulation boards, models and circuit board carriers.