IC Substrate - Thermal Analysis of IC Packaging Substrate

Nowadays, more and more IC package substrate / PCB system designs require thermal analysis.  Power consumption is a key problem in the design of packaging/PCB system, which requires careful consideration in both thermal and electrical fields.  For better geothermal analysis, we take heat conduction in solids as an example and take advantage of the duality of the two domains. Figure 1 and Table 1 describe the basic relationship between the electrical and thermal domains.

There are some differences between electrical and thermal domains, such as:

In the electrical domain, the current is confined to the flow of certain circuit elements, but in the thermal domain, the heat flow is emitted from the source in three dimensions through three heat conduction mechanisms (conduction, convection, and radiation)

Thermal coupling between components is more pronounced and difficult to separate than electrical coupling

Measurement tools are different.  For thermal analysis, infrared thermoimagers and thermocouples replace oscilloscopes and voltage probes

As below:

Q is the heat transferred per second in joules per second.

K is thermal conductivity (W/(K.m))

A is the cross-sectional area (m2) of the object.

Δ T for temperature difference

Δx is the thickness of the material

Hc is the convective heat transfer coefficient

HR is the radiation heat transfer coefficient

T1 is the initial temperature on one side

T2 is the temperature on the other side

T is the temperature of the solid surface (oC).

Tf is the average temperature of the fluid (oC).

Th is the hot end temperature (K).

Tc is the cold end temperature (K).

ε is the radiation coefficient of the body (for black body) (0~1)

σ = Stefan-Boltzmann constant =5.6703*10-8 (W/(m2K4))

SigrityTM Power DCTM is a proven electrothermal technology that has been used for many years in the design, analysis and acceptance of packaging and PCB applications.  The integrated electrical/thermal co-simulation enables the user to easily verify that the design meets the specified voltage and temperature thresholds without having to spend a lot of effort sift through many difficult-to-determine impact factors.  With this technology, you can obtain accurate design margin and reduce the manufacturing cost of the design.  The following figure shows the Power DC method for electrical/thermal co-simulation:

In addition to electrical/thermal co-simulation, PowerDC also provides other heat-related functions, such as:

Thermal model extraction

Thermal stress analysis

Multi-plate analysis

Chip package circuit board co-simulation

With these technologies and features, you can easily and quickly evaluate the heat flow and radiation of a package or printed circuit board design by graphical and quantitative methods.

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