Equation 5 · Part 2 · Comparing the Main Approaches to Chiplets and Advanced Packaging

Symbol P

\Delta T_j \;=\; P \sum_{i=1}^{N} R_{\mathrm{th},i},

P

What this part means

the power dissipated at that tier and each $R_{\mathrm{th},i}$ is the thermal resistance of one layer already between that tier and the heat sink — die bulk, bonding interface, or an intervening active tier.

Its job in the formula

P is an input to the expression that computes the quantity on the left.

Full expressionSymbol PArticle meaning

Where the article explains it

where P is the power dissipated at that tier and each $R_{\mathrm{th},i}$ is the thermal resistance of one layer already between that tier and the heat sink — die bulk, bonding interface, or an intervening active tier.

The passage around this formula

…package’s heat-removal path — typically the topmost die, under a lid or heat spreader — so the temperature rise at a given tier depends on everything the heat has to cross to reach that face: $\Delta T_j \;=\; P \sum_{i=1}^{N} R_{\mathrm{th},i}$ . where P is the power dissipated at that tier and each $R_{\mathrm{th},i}$ is the thermal resistance of one layer already between that tier and the heat sink — die bulk, bonding interface, or an intervening active tier. A tier two layers from the heat-removal face inherits the resistance of everything below…

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Learn the underlying idea

A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

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Sources cited in the article section

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