Substrate Structure With Hollow Pad Openings for Underfill Bonding
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Solution Overview
Problem
In semiconductor packaging, the bonding force between the underfill and the copper circuit layer is poor, leading to delamination issues and the popcorn phenomenon due to voids formed by larger particles in the underfill.
Innovation Solution
A substrate structure with a circuit layer and an insulating protection layer featuring active regions with reinforcing portions and hollow portions, which reduce the exposed area of the circuit layer and facilitate smooth flow of the underfill, enhancing bonding forces and preventing voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If multiple openings are formed to expose electrical contact pads, then the area where underfill contacts circuit layer is reduced, but larger particles in underfill cannot pass through causing voids and popcorn phenomenon
Solution Approach 1:
The insulating protection layer differentiates between active regions (with openings for electrical contact pads) and non-active regions (with full coverage). The non-active regions provide continuous dielectric material contact for strong bonding, while active regions minimize copper exposure. This local quality differentiation simultaneously achieves strong bonding and prevents popcorn phenomenon by ensuring adequate underfill flow paths.
Data Source
AI summary
A substrate structure is provided, in which an insulating protection layer is formed on a substrate body having a plurality of electrical contact pads, and the insulating protection layer has a plurality of openings corresponding to the plurality of exposed electrical contact pads, and the insulating protection layer is formed with a hollow portion surrounding a partial edge of at least one of the electrical contact pads at at least one of the openings, so as to reduce the barrier of the insulating protection layer.