Vertical Spacers in TIM for IC Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermal interface materials (TIM) in integrated circuit (IC) packages exhibit inefficient thermal conduction due to reduced space between the IC chip and lid in scaled-down devices, leading to increased thermal resistance and vulnerability to cracking when alternative materials or thinner lids are used.
Innovation Solution
The formation of vertical spacers on the IC chip within the TIM layer between the chip and lid, which are electroplated and designed to specific dimensions and spacing for improved thermal dissipation, reduces thermal resistance and enhances heat transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a thinner TIM layer is used to reduce space between IC chip and lid, then the package size is reduced, but thermal conduction efficiency deteriorates
Solution Approach 1:
The TIM layer is segmented by introducing vertical spacer structures that divide the thermal interface into multiple pathways. These spacers create a segmented thermal conduction path through the TIM layer, allowing heat to transfer more efficiently across the interface while maintaining a thin overall TIM thickness, thus resolving the contradiction between reduced package size and maintained thermal conduction efficiency.
2Reliability
If silver or gold alloys are used to replace TIM for lower thermal resistance, then thermal performance is improved, but material cost increases
Solution Approach 1:
Instead of using expensive silver or gold alloys throughout the entire TIM layer, the invention applies vertical spacer structures made of thermally conductive material at specific locations within the TIM layer. This local enhancement of thermal conductivity at critical heat transfer paths achieves improved thermal performance while using significantly less expensive materials, resolving the contradiction between thermal performance and material cost.
3Reliability
If silver or gold alloys are used to replace TIM, then thermal resistance is reduced, but chip cracking vulnerability increases
Solution Approach 1:
The invention uses vertical spacer structures made of thermally conductive material with appropriate mechanical properties, placed locally within the TIM layer. These spacers provide thermal conduction pathways without requiring the use of hard, brittle materials like silver or gold alloys that would crack the chip. The local application of thermally conductive spacers achieves reduced thermal resistance while maintaining chip structural integrity.
4Reliability
If lid thickness is reduced to lower lid thermal resistance, then thermal performance is improved, but chip vulnerability to cracking increases
Solution Approach 1:
The invention segments the thermal conduction path by introducing vertical spacer structures within the TIM layer. This segmentation allows the heat to transfer more efficiently through the TIM layer without requiring a thinner lid, thus achieving improved thermal performance while maintaining adequate lid thickness to protect the chip from cracking.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach achieves a significant reduction in thermal resistance, allowing for more efficient heat transfer from the IC chip to the lid, even with a thinner TIM layer, without increasing the risk of chip cracking, and is applicable across various IC package designs.
Implementation Method 1
a TIM layer, surrounding the vertical spacers, between the backside of the substrate and the plate
Implementation Method 2
electroplating vertical structures on the seed layer through a mask layer
Data Source
AI summary
Methods for reducing the junction temperature between an IC chip and its lid by including metal spacers in the TIM layer and the resulting devices are disclosed. Embodiments include providing a substrate, including integrated circuit devices, having front and back sides; forming vertical spacers on the backside of the substrate; providing a plate parallel to and spaced from the backside of the substrate; and forming a TIM layer, surrounding the vertical spacers, between the backside of the substrate and the plate.