Semiconductor Package Double-Layer Curing System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor packages face challenges in reliably stacking high-density semiconductor chips due to issues with solder bump expansion and interconnect reliability, particularly in fine-pitch designs, which can lead to short failures and reduced package reliability.
Innovation Solution
A semiconductor package design incorporating a double-layered curing system, where a first photo-curing layer is in contact with the upper portion of the solder bump and a second thermo-curing layer is in contact with the lower portion, with the first layer being cured before the second to prevent lateral expansion of solder bumps, thereby enhancing interconnect reliability and preventing short failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer curing material is used between semiconductor chips, then the manufacturing process is simple, but solder bumps may expand laterally causing short failures
Solution Approach 1:
The curing layer is divided into two distinct segments: a first curing layer containing a first curing agent and a second curing layer containing a second curing agent. This segmentation allows each layer to perform specific functions - the first layer prevents lateral expansion of solder bumps while the second layer provides structural support, thereby resolving the contradiction between manufacturing simplicity and interconnect reliability.
Solution Approach 2:
Different regions of the curing system are assigned different properties. The first curing layer is formulated with specific viscosity and curing characteristics to control solder bump lateral expansion, while the second curing layer has different properties optimized for structural support. This local differentiation of material properties enables simultaneous achievement of reliability and manufacturability.
2Volume of moving object
If high-density chip stacking is implemented, then package size is reduced, but solder bump expansion causes short failures
Solution Approach 1:
The segmented curing layer structure enables high-density stacking by preventing solder bump lateral expansion through the first curing layer's specific formulation. This allows chips to be placed closer together without risking short failures, thus reducing package volume while maintaining reliability.
Solution Approach 2:
The invention changes key parameters of the curing system - using different viscosity values, curing temperatures, and chemical compositions for the first and second curing layers. These parameter changes enable precise control over solder bump behavior during the stacking process, making high-density packaging reliable.
3Strength
If curing temperature is increased to improve bond strength, then attachment reliability improves, but solder bump lateral expansion increases
Solution Approach 1:
The curing process is segmented into two stages with different temperature profiles. The first curing layer cures at a lower temperature that prevents solder bump lateral expansion, while the second curing layer cures at a higher temperature to provide strong structural support. This temporal and functional segmentation resolves the contradiction between attachment strength and interconnect reliability.
Solution Approach 2:
The first curing layer performs a preliminary action by curing first to establish a protective barrier that prevents solder bump lateral expansion. Only after this preliminary protective layer is formed does the second curing layer cure to provide final structural strength, ensuring that high temperature curing does not cause short failures.
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 double-layered curing system effectively prevents lateral expansion of solder bumps, reducing the likelihood of short failures and improving the reliability of high-density chip stacks by ensuring robust attachment and reliable connections between semiconductor chips.
Implementation Method 1
The first curing layer may include a first photo-curing agent
Implementation Method 2
The second curing layer may include a first thermo-curing agent
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A semiconductor package includes a lower semiconductor chip having a lower semiconductor substrate and upper pads on a top surface of the lower semiconductor substrate, an upper semiconductor chip stacked on the lower semiconductor chip, the upper semiconductor chip including an upper semiconductor substrate and solder bumps on a bottom surface of the upper semiconductor substrate, and a curing layer between the lower semiconductor chip and the upper semiconductor chip, the curing layer including a first curing layer adjacent to the upper semiconductor chip, the first curing layer including a first photo-curing agent, and a second curing layer between the first curing layer and the top surface of the lower semiconductor substrate, the second curing layer including a first thermo-curing agent.