What is package thermal resistance?

Package thermal resistance is the measure of a package’s heat dissipation capability from a die’s active surface (junction) to a specified reference point (case, pin, ambient, etc.). The value of thermal resistance depends on many factors, such as ambient temperature, PCB board used and much more.

What is the correct formula for thermal resistance of a slab?

Absolute thermal resistance It is the reciprocal of thermal conductance. 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 junction case thermal resistance?

Junction-to-case thermal resistance (θJC) is defined as the thermal resistance from the semiconductor junction to the case of the oscillator (junction-to-case). A low value of θJC corresponds to increased heat conduction and a high value corresponds with decreased heat conduction. 7.

What is thermal resistance 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.

How do you calculate thermal resistance junction ambient?

Equation: Rth(j-a) ＝ (Tj Max – Ta） / P Max

1. Rth(j-a): Junction-to-ambient thermal resistance.
2. Tj Max: Maximum junction temperature.
3. Ta: Ambient temperature (temperature condition of P Max)
4. P Max: Maximum power dissipation.

How do you calculate Theta JA?

Temperatures at specific locations are extracted and used in relevant theta or psi calculations, just as if they had been obtained from lab testing. Example: To determine theta-JA, the lab test or model data needed is TJ, TA, and P. If TJ= 80°C, TA = 25°C, and P = 1.0W, then: θJA = (80°C – 25°C) / 1.0W = 55 °C/W.

How do you calculate total thermal resistance?

As indicated in Equation 2, the value of the thermal resistance can be determined by dividing the thickness with thermal conductivity of the specimen.

What is maximum junction temperature rating?

All semiconductors have some specified safe upper limit for junction temperature (TJ), usually on the order of 150°C (sometimes 175°C). Like maximum power supply voltages, maximum junction temperature is a worst case limitation which must not be exceeded.

How do you calculate junction-to-ambient thermal resistance?

How do you test thermal resistance?

Thermal Resistance (R) is a measure of resistance to heat flow through a given thickness of material (related directly to the R-value). Thermal resistance is determined by taking the thickness of a sample and dividing it by its thermal conductivity.

What is the use of BGA packaging?

BGA packaging can be used for high-performance applications with high thermal and electrical re- quirements. BGAs fit ICs into a smaller footprint, decreasing pitch spacing, by utilizing an array of solder ball connections. This allows for a higher density of I/O connections than that of conventional QFPs or PGAs.

What is the difference between ceramic BGA and flip chip BGA?

The ceramic BGA package uses a higher melting ball (90Pb/10Sn) with eutectic attachment to the die and board. Column grid array (CGA or CCGA) is similar to BGA except it uses column interconnects instead of balls. Flip chip BGA (FCBGA) is similar to BGA, except it is internal to the package and flip chip die is used.

What does BGA stand for?

Ball Grid Array (BGA) Packaging clad bismaleimide triazine (BT) laminate. Four-metal layer substrate designs generally contain ad- ditional power and/or ground planes to improve electrical and thermal performance. The die and bonds are protected and encapsulated with molding compound.

What is the difference between a QFP and a BGA?

Normally, because of the larger ball pitch (typically 1.27 mm) of a BGA over a QFP or PQFP, the overall package and board assembly yields can be better. From a performance perspective, the thermal and electrical characteristics can be better than that of conventional QFPs or PQFPs.