Computer-Aided Thermal Anlaysis of a Hybrid Mutlistage Active Bandpass Filter/Amplifier

Cook, Karen; Kerns, D.V.; Nagle, H. Troy; Slagh, T. D.; Ruwe, Victor W

doi:10.1109/tphp.1976.1135151

Cited by 7 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Balents et al [2] used the constant value of 45˚ as the heat spreading angle and conducted an approximate heat transfer analysis concerning a heat dissipating element mounted directly on a ceramic substrate which was bonded to a metal baseplate. After a while, the 45˚ heat spreading model of Balents et al was used by Cook et al [3] in 1976, and thereafter many attempts have been made to modify the value or extend the theory of the heat spreading angle. Nevertheless, the above-mentioned 45˚ heat spreading angle is still familiar among thermal designers.…”

Section: Introductionmentioning

confidence: 99%

Two-Dimensional Numerical Investigation on Applicability of 45<sup>。</sup>Heat Spreading Angle

Koito¹,

Okamoto²,

Tomimura³

2014

JECTC

View full text Add to dashboard Cite

The 45˚ heat spreading angle is familiar among thermal designers. This angle has been used for thermal design of electronic devices, and provides a heat spreading area inside a board, e.g. printed circuit board, which is placed between a heat dissipating element and a relatively large heat sink. By using this angle, the heat transfer behavior can be estimated quickly without using high-performance computers. In addition, the rough design can be made easily by changing design parameters. This angle is effective in a practical situation; however, the discussion has not been made sufficiently on the applicability of the 45˚ heat spreading angle. In the present study, therefore, the extensive numerical investigation is conducted for the rational thermal design using the 45˚ heat spreading angle. The two-dimensional mathematical model of the board is considered; the center of the top is heated by a heat source while the bottom is entirely cooled by a heat sink. The temperature distribution is obtained by solving the heat conduction equation numerically with the boundary conditions. From the numerical results, the heat transfer behavior inside the board is shown and its relation with the design parameters is clarified. The heat transfer behavior inside the 45˚ heat spreading area is also evaluated. The applicability is moreover discussed on the thermal resistance of the board obtained by the 45˚ heat spreading angle. It is confirmed that the 45˚ heat spreading angle is applicable when the Biot number is large, and then the equations are proposed to calculate the Biot number index to use the 45˚ angle. Furthermore, the validity of the 45˚ heat spreading angle is also confirmed when the isothermal boundary condition is used at the cooled section of the board.

show abstract

Section: Introductionmentioning

confidence: 99%

Two-Dimensional Numerical Investigation on Applicability of 45<sup>。</sup>Heat Spreading Angle

Koito¹,

Okamoto²,

Tomimura³

2014

JECTC

View full text Add to dashboard Cite

show abstract

“…Another team developed a set of equations for heat transfer in integrated circuits [2]. Some have performed thermal modeling with the assumption that the spreading angle is 45 degrees [3]. Others have rejected the 45 degree spreading angle assumption all together [4] [5], and some have used other spreading angles of 32.5 degrees [6] or 26.6 degrees [7] claiming that they are a more accurate approximation.…”

mentioning

confidence: 99%

A Simple Closed Form Solution to Single Layer Heat Spreading Angle Appropriate for Microwave Hybrid Modules

Sturdivant¹,

Bogdon²,

Chong³

2016

JECTC

View full text Add to dashboard Cite

A simple equation for heat spreading angle is derived which is useful for cases with a single layer thermal spreader. The derivation starts with Fourier's heat transfer law. Heat spreading in two dimensions is then introduced which results in a quadratic equation relative to spreading angle. The result is a closed form equation for heat spreading angle. Calculations using the equation are compared to 3D finite element simulations which show agreement acceptable for most practical applications and over a wide range of physical dimensions and thermal conductivities. A normalized dimensional parameter is defined which is used to generate a curve fit equation of the spreading angle. A three step procedure is then presented which allows the calculation of the spreading angle and temperature rise in the thermal spreader. The result has application for initial calculations of temperature rise in microwave hybrid modules and electronic packages such as heat sinks for high power amplifiers. This is because it is common for these types of modules and packages to use a single layer heat spreader in copper-tungsten (CuW) or copper-molybdenum (CuMo) connected to a cold plate. An important benefit of this method is that it allows microwave hybrid designers and high power amplifier packaging engineers a method to quickly perform trade studies to determine the maximum mounting temperature for integrated circuits.

show abstract

Thermal Design

Agajanian¹

1979

Microelectronic Packaging

View full text Add to dashboard Cite

Computer-Aided Thermal Anlaysis of a Hybrid Mutlistage Active Bandpass Filter/Amplifier

Cited by 7 publications

References 1 publication

Two-Dimensional Numerical Investigation on Applicability of 45<sup>。</sup>Heat Spreading Angle

Two-Dimensional Numerical Investigation on Applicability of 45<sup>。</sup>Heat Spreading Angle

A Simple Closed Form Solution to Single Layer Heat Spreading Angle Appropriate for Microwave Hybrid Modules

Thermal Design

Contact Info

Product

Resources

About

Computer-Aided Thermal Anlaysis of a Hybrid Mutlistage Active Bandpass Filter/Amplifier

Cited by 7 publications

References 1 publication

Two-Dimensional Numerical Investigation on Applicability of 45&lt;sup&gt;。&lt;/sup&gt;Heat Spreading Angle

Two-Dimensional Numerical Investigation on Applicability of 45&lt;sup&gt;。&lt;/sup&gt;Heat Spreading Angle

A Simple Closed Form Solution to Single Layer Heat Spreading Angle Appropriate for Microwave Hybrid Modules

Thermal Design

Contact Info

Product

Resources

About

Two-Dimensional Numerical Investigation on Applicability of 45<sup>。</sup>Heat Spreading Angle

Two-Dimensional Numerical Investigation on Applicability of 45<sup>。</sup>Heat Spreading Angle