Heat-Spreading Lid Openings for Multi-Chip Package Reliability
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Solution Overview
Problem
Forming a reliable chip package structure with multiple chips is challenging due to thermal stress and expansion mismatch between components, leading to potential delamination and cracking in adhesive layers.
Innovation Solution
Incorporating a heat-spreading lid with strategically designed openings and a ring structure to manage thermal stress by reducing the transmission path and enhancing adhesive layer reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple chips are integrated into a single package structure, then functional complexity and integration density are improved, but thermal stress and expansion mismatch increase leading to adhesive layer failure
Solution Approach 1:
The lid is segmented by forming openings that divide the continuous lid structure into separate regions. These openings segment the thermal stress transmission path, preventing stress from propagating across the entire lid and reducing the risk of adhesive layer delamination while maintaining structural integrity for multi-chip integration
Solution Approach 2:
The openings act as intermediary elements between different chips and their respective heat-spreading regions. By introducing these intermediate void spaces, thermal stress is isolated and managed locally around each chip rather than being transmitted across the entire package, thereby protecting the adhesive layers
2Temperature
If heat-spreading lid covers entire package area, then thermal management is improved, but thermal stress transmission increases causing adhesive layer damage
Solution Approach 1:
The continuous heat-spreading lid is segmented into separate heat-spreading regions by forming openings between them. Each region independently manages heat for its associated chip while the openings prevent thermal stress from transmitting across the entire lid structure, thus maintaining effective thermal management while reducing harmful stress transmission
Solution Approach 2:
Material is extracted from the lid to form openings in strategic locations. By removing material in these specific areas, the transmission path for thermal stress is interrupted while the remaining lid structure continues to provide effective heat spreading for each chip region
3Reliability
If openings are added to lid structure, then thermal stress transmission is reduced improving reliability, but manufacturing complexity increases
Solution Approach 1:
The openings are formed in the lid during the packaging process before final assembly, using the mold cavity structure to define the opening locations. This preliminary formation of openings simplifies the overall manufacturing process compared to post-processing methods, as the openings are created as part of the standard packaging workflow rather than requiring additional complex steps
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
The design effectively reduces thermal stress, preventing delamination and cracking in adhesive layers, thereby improving the reliability and integrity of the chip package structure.
Implementation Method 1
a heat-spreading lid over the wiring substrate and covering the first chip structure
Implementation Method 2
an adhesive layer between the first chip structure and the heat-spreading lid
Data Source
AI summary
A chip package structure is provided. The chip package structure includes a wiring substrate. The chip package structure includes a first chip structure over the wiring substrate. The chip package structure includes a heat-spreading lid over the wiring substrate and covering the first chip structure. The heat-spreading lid includes a ring structure and a top plate, the ring structure surrounds the first chip structure, the top plate covers the ring structure and the first chip structure, the top plate has a first opening, the first opening is between the first chip structure and the ring structure in a top view of the heat-spreading lid and the first chip structure, the ring structure has a second opening, the first chip structure is in the second opening, the second opening has an inner wall facing the first chip structure, and the inner wall has a recess.