Stacked Silicon Package Lid With Flexible Thermal Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chip packaging schemes face challenges with temperature control due to rigid connections between the lid and IC dies, leading to uneven heat transfer and increased stress, which can result in performance differences and potential damage to IC dies.
Innovation Solution
A chip package design that includes a lid conductively coupled to the IC die but mechanically decoupled from a stiffener, using thermal interface materials and engineered features on the lid to enhance heat transfer and reduce stress, along with a method that involves attaching a stiffener to the substrate before mounting IC dies to minimize warpage and delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the lid is rigidly connected to the IC die using adhesive, then the lid provides mechanical protection, but heat transfer becomes uneven and stress increases
Solution Approach 1:
The lid is divided into multiple sections with varying degrees of freedom. The first lid portion is rigidly connected to provide protection, while the second lid portion is flexibly connected to accommodate thermal expansion and enable uniform heat transfer across different die heights.
Solution Approach 2:
The connection between the lid and substrate changes from completely rigid to partially flexible. The flexible connection allows the lid to adapt to temperature changes and die height variations, achieving both mechanical protection and uniform heat transfer.
2Stability of the object's composition
If the lid is rigidly connected to the IC die, then structural stability is improved, but delamination and warpage increase
Solution Approach 1:
The lid connection transitions from a static rigid structure to a dynamic system where the second lid portion can move independently. This dynamic flexibility allows the structure to maintain stability while accommodating thermal and mechanical stresses, preventing delamination and warpage.
3Ease of manufacture
If adhesive is used to secure the lid over the die, then the lid is easily attached, but stress is increased on the chip package
Solution Approach 1:
The lid attachment system is segmented into two distinct connection methods: adhesive bonding for the first lid portion and flexible mechanical connection for the second lid portion. This segmentation allows easy attachment while distributing stress through the flexible connection that can accommodate dimensional changes.
4Productivity
If tolerance issues and die height differences are present, then manufacturing is simplified, but heat transfer rate varies significantly between dies
Solution Approach 1:
Different portions of the lid have different connection characteristics. The first lid portion provides rigid protection, while the second lid portion provides flexible thermal coupling that adapts to local die height variations, ensuring consistent heat transfer across all dies despite manufacturing tolerances.
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 design improves heat transfer between the lid and IC dies, reducing delamination and warpage, and allows for more uniform performance across IC dies, enhancing the reliability and efficiency of the chip package.
Implementation Method 1
The second surface of the lid is conductively coupled to the IC die
Data Source
AI summary
A method and apparatus are provided which improve heat transfer between a lid and an IC die of an IC (chip) package. In one embodiment, a chip package is provided that includes a first IC die, a package substrate, a lid and a stiffener. The first IC die is coupled to the package substrate. The stiffener is coupled to the package substrate and circumscribes the first IC die. The lid has a first surface and a second surface. The second surface faces away from the first surface and towards the first IC die. The second surface of the lid is conductively coupled to the IC die, while the lid is mechanically decoupled from the stiffener.