Bonding Tool Groove Structure for Uniform Chip Underfill
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Solution Overview
Problem
Existing semiconductor bonding apparatuses face issues with uneven heights of semiconductor chips due to resin volume variations, leading to thickness inconsistencies and air bubbles in the underfill material, which can cause vapor explosions and reliability issues during the reflow process.
Innovation Solution
A semiconductor manufacturing apparatus with a bonding tool featuring protruding portions and a groove to manage underfill material overflow and air bubble removal, ensuring uniform chip heights and preventing air bubble entrapment through strategically placed notch portions and a vacuum system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the bonding tool presses the semiconductor chip against the interconnection substrate with fixed height, then the bonding process can be completed, but unevenness in chip heights occurs due to resin volume variations
Solution Approach 1:
The bonding tool incorporates protruding portions with different heights (first protruding portion and second protruding portion) at different locations. The first protruding portion has a height corresponding to a first target height, while the second protruding portion has a height corresponding to a second target height. This local variation in height allows different regions of the chip to be pressed to different target heights, compensating for resin volume variations and achieving uniform chip height across the substrate.
Solution Approach 2:
The bonding tool's pressing surface is segmented into multiple protruding portions with different heights rather than using a single flat surface. This segmentation allows independent height control for different regions, enabling precise compensation for local variations in resin volume and achieving uniform chip positioning.
2Reliability
If the resin is applied to fill the space between chip and substrate, then encapsulation is achieved, but air bubbles become trapped in the resin
Solution Approach 1:
The groove portion is designed to collect and extract air bubbles from the resin before final encapsulation. The groove provides a designated space where air bubbles can accumulate and be removed from the encapsulation region, preventing them from being trapped in the final sealed structure and eliminating the harmful effects of air bubbles on package reliability.
Solution Approach 2:
The groove portion, which initially appears as a void or defect in the encapsulation structure, is actually beneficial as it serves as an air bubble collection zone. By intentionally creating this groove, air bubbles are directed to a specific location where they can be managed, converting the potential harm of air bubble entrapment into a controlled feature that protects the overall encapsulation quality.
3Productivity
If air bubbles remain in the resin during encapsulation, then the bonding process continues, but vapor explosions occur during subsequent reflow process
Solution Approach 1:
The groove portion is designed to collect air bubbles during the bonding and encapsulation process, before the reflow process begins. This preliminary action of air bubble collection and removal prevents the accumulation of air bubbles that would otherwise cause vapor explosions during the subsequent reflow process, ensuring safe and efficient production.
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 solution effectively prevents uneven chip heights, eliminates air bubbles, and enhances the reliability of semiconductor packages by ensuring uniform encapsulation and preventing vapor explosions during the reflow process.
Implementation Method 1
a vacuum system
Data Source
AI summary
A semiconductor manufacturing apparatus includes a stage capable of holding thereon an interconnection substrate. A tool presses the interconnection substrate and a semiconductor chip against each other between the tool and the stage. The tool includes a main body portion that has a holding surface holding thereon the semiconductor chip. A first protruding portion is provided along an outer edge of the holding surface and protrudes from the holding surface toward the stage. A second protruding portion is provided outside of the first protruding portion along the outer edge of the holding surface and protrudes from the holding surface toward the stage. A groove portion is provided between the first protruding portion and the second protruding portion.