Semiconductor Package Trench Interconnects for Fine-Pitch Reliability
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Solution Overview
Problem
The challenge of reducing the pitch of connection terminals in semiconductor chips to meet the demand for smaller and more densely packed electrode terminals has not been adequately addressed, leading to potential fabrication failures and increased costs.
Innovation Solution
A semiconductor package design featuring trenches in the package substrate filled with an anisotropic conductive pattern comprising conductive capsules and a polymer layer, coupled with a semiconductor chip through coupling pillar patterns, and solder balls on the substrate surface, where the conductive capsules have a low melting point to allow low-temperature processing and reduce electrical connections between adjacent patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the pitch of connection terminals is reduced to meet demand for smaller semiconductor chips, then the density of electrode terminals is improved, but fabrication failures increase due to process complexity and electrical short circuits between adjacent patterns
Solution Approach 1:
The patent divides the continuous conductive structure into discrete conductive capsules separated by insulating polymer layers. Each conductive capsule is independently encapsulated, preventing electrical short circuits between adjacent connection terminals while maintaining high density. This segmentation allows reduced pitch without increasing fabrication failures.
Solution Approach 2:
The insulating polymer layer acts as an intermediary between adjacent conductive capsules, providing electrical isolation while allowing mechanical coupling. This intermediary structure enables closer spacing of connection terminals without causing electrical short circuits, thereby improving terminal density while maintaining reliability.
2Strength
If conventional high-temperature processing is used for solder balls, then strong electrical connections are achieved, but damage to the semiconductor chip and surrounding structures occurs
Solution Approach 1:
The patent changes the melting point parameter of the conductive material from conventional high-melting-point solder (requiring >200°C) to low-melting-point conductive capsule material (melting at 50-150°C). This parameter change enables strong electrical connections to be formed at lower temperatures, avoiding thermal damage to the semiconductor chip and surrounding structures.
Solution Approach 2:
The conductive capsule material undergoes a phase transition from solid to liquid at its low melting point during the bonding process. This phase transition enables the material to flow and form strong electrical connections at low temperatures (50-150°C), avoiding the high temperatures (>200°C) that would cause thermal damage to the chip.
3Quantity of substance
If adjacent conductive patterns are placed closer together to reduce pitch, then terminal density is improved, but electrical short circuits between adjacent patterns increase
Solution Approach 1:
The patent segments the conductive material into discrete, encapsulated units separated by insulating polymer layers. This segmentation creates physical and electrical isolation between adjacent conductive patterns, preventing electrical short circuits even when terminals are placed at reduced pitch distances.
Solution Approach 2:
The patent uses a composite structure consisting of conductive capsule material embedded in an insulating polymer matrix. This composite material provides both electrical conductivity for signal transmission and electrical isolation through the polymer layer, enabling close spacing of terminals without causing short circuits.
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 reduces fabrication failures and costs by enabling low-temperature processing and preventing electrical short circuits, improving the reliability and efficiency of the semiconductor package.
Implementation Method 1
an anisotropic conductive pattern provided on the conductive coupling pattern and the substrate pad to fill the trench, the anisotropic conductive pattern including conductive capsules and a polymer layer enclosing the conductive capsules
Implementation Method 2
the conductive capsules have a low melting point to allow low-temperature processing
Implementation Method 3
a polymer layer enclosing the conductive capsules
Data Source
AI summary
A semiconductor package may include a package substrate having a first surface and a second surface, which are opposite to each other, and including a trench formed in the first surface, a substrate pad provided on the package substrate to cover a bottom surface of the trench, a conductive coupling pattern in contact with a top surface of the substrate pad, an anisotropic conductive pattern provided on the conductive coupling pattern and the substrate pad to fill the trench, the anisotropic conductive pattern including conductive capsules and a polymer layer enclosing the conductive capsules, a semiconductor chip mounted on the first surface of the package substrate, and a coupling pillar pattern provided between the package substrate and the semiconductor chip and connected to the conductive coupling pattern in the trench. A top surface of the anisotropic conductive pattern may be coplanar with the first surface of the package substrate.