Semiconductor Package Pad Structure for Stable Fine-Pitch Solder Connections
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Solution Overview
Problem
Existing semiconductor packages face challenges in achieving a high degree of integration and reliability of electrical connection paths due to the decreasing size and increasing complexity of pads, which affects the stability and efficiency of electrical connections.
Innovation Solution
The semiconductor package includes an insulating layer surrounding first and second pads with solders in between, margin portions providing lateral space, and an underfill on the insulating layer surface, ensuring stable vertical compression and increased contact area of the solders, thereby enhancing the integration and reliability of electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the width or pitch of pads is decreased to increase integration, then the degree of integration of electrical connection paths increases, but the reliability of electrical connections deteriorates
Solution Approach 1:
The pad structure is segmented into multiple functional layers: the pad itself, margin portions surrounding the pad, and underfill material filling the space between adjacent pads. This segmentation allows each component to perform its specific function - the pad provides electrical connection, the margin portions provide mechanical support and prevent solder overflow, and the underfill provides additional structural stability - thereby maintaining connection reliability even as pad size decreases for higher integration
Solution Approach 2:
The margin portions and underfill material act as preventive protective structures formed beforehand to prevent potential connection failures. The margin portions surround the pads to prevent solder overflow during the bonding process, while the underfill material fills the spaces between pads to prevent mechanical stress and delamination, thus cushioning against reliability issues before they occur
2Quantity of substance
If the width or pitch of pads is decreased to increase integration, then the degree of integration of electrical connection paths increases, but the stability of electrical connections deteriorates
Solution Approach 1:
The connection structure is divided into stable foundational elements (margin portions and underfill) that support the smaller, more integrated pads. This segmentation provides a stable framework that maintains connection stability even as the pads themselves become smaller and more densely packed
Solution Approach 2:
Different regions of the package are given different properties: the margin portions provide mechanical support and structural stability around each pad, while the underfill material provides bulk structural support between pads. This local differentiation of properties ensures that stability-critical areas have enhanced structural characteristics, compensating for the reduced size of individual connection paths
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 configuration improves the degree of integration and reliability of electrical connection paths by stabilizing the contact area of solders, reducing the risk of overflow, and maintaining impedance stability and signal integrity.
Implementation Method 1
second pads electrically connected to the first pads; solders between and connected to the first pads and the second pads... an underfill on an upper surface of the insulating layer and surrounding each of the second pads, wherein a level of lower surfaces of the second pads is lower than a level of the upper surface of the insulating layer
Implementation Method 2
an underfill on an upper surface of the insulating layer and surrounding each of the second pads
Implementation Method 3
an insulating layer; first pads respectively surrounded by the insulating layer
Data Source
AI summary
A semiconductor package includes an insulating layer; first pads respectively surrounded by the insulating layer; second pads electrically connected to the first pads; solders between and connected to the first pads and the second pads, and respectively surrounded by the insulating layer, and margin portions including an insulating material, surrounding the solders, and respectively surrounded by the insulating layer.