Trench Structure for Controlling Underfill Flow in Semiconductor Assembly
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Solution Overview
Problem
The challenge in semiconductor manufacturing is controlling the outward flow of underfill material during the assembly of semiconductor devices, which often results in excess material bleeding beyond the die footprint, potentially covering unintended areas such as contact pads or sensors, due to the difficulty in dispensing the proper amount and location of underfill between the semiconductor die and the substrate.
Innovation Solution
A method involving the formation of a trench over the substrate, with an interconnect structure and underfill material within the trench, allows for precise placement of the semiconductor die over the underfill before curing, containing the underfill material and preventing it from contacting sensitive areas or spreading beyond the intended boundaries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If underfill material is dispensed between semiconductor die and substrate, then structural support and environmental isolation are provided, but excess material bleeds outward beyond die footprint covering contact pads or sensors
Solution Approach 1:
The patent divides the substrate surface into distinct regions: a first region for receiving the semiconductor die, a second region for contact pads, and a third region for sensors. This spatial segmentation prevents underfill material dispensed in the first region from bleeding into the second and third regions, thereby maintaining manufacturing precision while providing reliable structural support and environmental isolation.
Solution Approach 2:
The patent applies different properties to different regions of the substrate. The first region has properties optimized for underfill reception and die attachment, while the second and third regions maintain their original properties for electrical connection and sensing functions. This local differentiation ensures that underfill material provides structural support where needed without interfering with contact pads or sensors.
2Strength
If underfill material is dispensed to provide structural support, then the proper amount and location are difficult to control
Solution Approach 1:
By segmenting the substrate into distinct functional regions, the patent creates natural boundaries that guide underfill material placement. The underfill can be dispensed freely in the first region without concern for bleeding into other areas, significantly easing the manufacturing process while ensuring adequate structural support.
Solution Approach 2:
The substrate is pre-configured with distinct regions before underfill dispensing. This preliminary arrangement of functional zones eliminates the need for precise real-time control during underfill application, as the material naturally remains within the designated first region due to the pre-established spatial boundaries.
3Quantity of substance
If underfill material flows outward, then it can cover contact pads or sensors on the substrate
Solution Approach 1:
The patent segments the substrate surface into a first region for underfill placement and separate second and third regions for contact pads and sensors. This physical separation ensures that underfill material, even if it flows outward, remains confined to the first region and cannot obstruct electrical connections or sensing elements.
Solution Approach 2:
Different regions of the substrate are assigned different functional qualities: the first region accommodates underfill material for structural support, while the second and third regions maintain their sensitivity and conductivity properties. This local functional differentiation prevents harmful interactions between underfill material and sensitive components.
Data Source
AI summary
A semiconductor device has a substrate including an opening. A trench is formed over the substrate around the opening. An interconnect structure is formed in the trench. An underfill material is disposed over the interconnect structure. A first semiconductor die is disposed over the underfill material prior to curing the underfill material. An active region of the first semiconductor die is disposed over the opening in the substrate. The trench contains the outward flow of underfill material. Underfill material is blocked from flowing over unintended areas on the surface of substrate, into the opening in the substrate, and over sensors of the first semiconductor die. A second semiconductor die is disposed over the substrate. The trench is formed by a first and second dam or a first insulating layer. A second insulating layer is formed over the first insulating layer. A dam is formed over the second insulating layer.