Dummy Pattern Mitigates Stress in Semiconductor Passivation Layers
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Solution Overview
Problem
Miniaturization of semiconductor devices leads to increased complexity in manufacturing, resulting in issues like poor structural configuration and delamination, which can cause yield loss and increase manufacturing costs, particularly due to stress and pressure during thermal curing processes that may crack passivation layers and interconnect structures.
Innovation Solution
Incorporating a dummy pattern coupled to or separate from the contact pad overlaying a passivation layer and interconnect structure to act as a buffer and mitigate stress and pressure during curing, thereby preventing cracks from propagating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If miniaturization of semiconductor devices is pursued to reduce size and cost, then device size and manufacturing cost are reduced, but structural configuration deteriorates and delamination occurs due to increased manufacturing complexity and stress
Solution Approach 1:
The dummy pattern is formed in advance during the manufacturing process, before the thermal curing process occurs. This preliminary structural preparation creates a buffer zone that will later mitigate stress during curing, preventing cracks and delamination before they can occur in the actual operation phase
Solution Approach 2:
The dummy pattern acts as an intermediary element between the contact pad and the surrounding structure. It serves as a buffer that absorbs and distributes stress, mediating the mechanical interactions during thermal curing and preventing direct stress transmission that would cause cracks in the passivation layer and interconnect structures
2Ease of manufacture
If thermal curing process is applied to assemble semiconductor components, then component assembly is achieved, but stress and pressure cause cracks in passivation layers and interconnect structures
Solution Approach 1:
The dummy pattern is specifically designed as a cushioning structure that is already in place before the thermal curing process begins. During curing, this dummy pattern absorbs excess stress and pressure, cushioning the passivation layer and interconnect structures from crack-inducing forces while still allowing the polymer to cure and bond components together
3Adaptability or versatility
If manufacturing operations are increased to achieve greater functionality in miniaturized devices, then device functionality is improved, but yield loss increases due to poor structural configuration and delamination
Solution Approach 1:
The dummy pattern can be implemented as multiple separate dummy units arranged in an array around the contact pad, or as a continuous dummy structure. This segmentation allows flexibility in design and manufacturing while providing distributed stress relief throughout the structure, preventing delamination and maintaining high yield rates even as device functionality increases
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 dummy pattern effectively reduces the likelihood of cracks in passivation layers and interconnect structures, enhancing the reliability of semiconductor packages by alleviating stress and pressure during thermal curing processes.
Implementation Method 1
a dummy pattern coupled to or separate from the contact pad overlaying a passivation layer and interconnect structure to act as a buffer and mitigate stress and pressure during curing
Data Source
AI summary
A semiconductor package includes a semiconductor substrate, an interconnect structure disposed over the substrate, a first passivation layer disposed over an interconnect structure, a contact pad disposed over the first passivation layer, a dummy pattern disposed around the contact pad and over the first passivation layer, and a second passivation layer overlaying the dummy pattern and the contact pad.