Semiconductor Package Cavity Structure for Shorter Bonding Wires
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Solution Overview
Problem
Existing semiconductor package structures suffer from long signal propagation paths and high electrical resistance, leading to signal integrity issues, reduced operating speed, and increased manufacturing costs.
Innovation Solution
A semiconductor package structure with a package substrate featuring a dam structure and cavity for semiconductor die placement, reducing bonding wire length and encapsulating layer thickness, thereby minimizing signal propagation path and enhancing heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional semiconductor package structures are used, then manufacturing is simpler, but signal propagation path is long and electrical resistance is high
Solution Approach 1:
The patent introduces a cavity structure in the package substrate that extends vertically from the top surface toward the bottom surface. The semiconductor die is mounted at the bottom of this cavity, allowing bonding wires to connect directly from the die pads to substrate pads through the cavity space. This vertical dimension utilization reduces the horizontal signal propagation path length while maintaining electrical connectivity.
Solution Approach 2:
The semiconductor die is nested within the cavity formed in the package substrate. The cavity acts as a recessed space that accommodates the die, allowing the bonding wires to be shorter as they connect within the cavity volume rather than spanning across the entire substrate surface. This nesting arrangement reduces the bonding wire length and signal propagation path.
2Speed
If bonding wire length is reduced to improve signal integrity, then operating speed improves, but manufacturing precision requirements increase
Solution Approach 1:
The cavity is pre-formed in the package substrate before the semiconductor die is mounted. This preliminary action creates a predetermined recessed space with specific dimensional tolerances, ensuring that when the die is placed in the cavity, the bonding wire length is automatically controlled within acceptable ranges. The cavity acts as a mechanical guide that facilitates precise die positioning.
Solution Approach 2:
The cavity provides a localized region with optimized geometric properties for die mounting. The cavity's depth and width are specifically designed to match the die thickness and footprint, creating a tailored fitting space that ensures precise die placement and optimal bonding wire length without requiring high-precision placement equipment across the entire substrate.
3Temperature
If package thickness is reduced to improve heat dissipation, then thermal performance improves, but structural stability may worsen
Solution Approach 1:
The package substrate is segmented into multiple functional layers including the cavity structure, which divides the substrate thickness into distinct regions. The cavity creates a stepped configuration that reduces the overall package height while maintaining adequate structural support. The encapsulating material further segments the package by filling the cavity and surrounding the die, providing mechanical support and thermal pathways.
Solution Approach 2:
The cavity is strategically positioned and dimensioned to provide localized thickness reduction in the package substrate. The cavity depth is optimized to reduce package height and improve heat dissipation while the surrounding substrate material maintains structural integrity. The encapsulating material compensates for the cavity-induced structural reduction by providing additional mechanical support.
Data Source
AI summary
A semiconductor package structure is provided. The semiconductor package structure includes a semiconductor die, a package substrate, and at least one bonding wire. The package substrate includes a dam structure to define a space where the semiconductor die is placed. The bonding wire is electrically connected between the semiconductor die and the package substrate.