Thermographic Detection of TSV Joint Failures in Stacked Semiconductor Dies
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Solution Overview
Problem
Joint failures between vertically stacked semiconductor dies, caused by electrical open failures due to misalignment or disconnection of through silicon vias (TSVs), are difficult to detect in high-bandwidth semiconductor packages, leading to reduced performance and reliability.
Innovation Solution
A method involving a thermographic image analysis to detect joint failures by applying heat to the base substrate of a semiconductor die stack, which reveals temperature differences on the surface of the upper die, indicating normal or failed connections between TSVs, using a thermographic camera and processor to identify and locate these failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If semiconductor dies are vertically stacked to increase storage capacity and bandwidth, then the number of embedded dies increases, but joint failures between TSVs occur causing electrical open failures
Solution Approach 1:
The patent applies preliminary action by performing thermographic inspection before final packaging to detect joint failures in TSV connections between stacked dies. This early detection allows identification of electrical open failures before they reach the customer, enabling rework or replacement while maintaining high die stacking density.
2Measurement precision
If traditional inspection methods are used for joint failures, then detection capability is limited, but inspection time and complexity increase
Solution Approach 1:
The patent replaces mechanical/electrical inspection methods with thermographic imaging technology. By applying heat to the semiconductor package and capturing thermal images, the system detects temperature differences caused by joint failures in TSV connections. This non-contact thermal method provides rapid, precise detection without complex mechanical probing or electrical testing procedures.
Solution Approach 2:
The patent changes the detection parameter from electrical properties to thermal properties. By measuring temperature distribution and differences in the semiconductor package under thermal excitation, the system identifies joint failures through thermal signatures rather than electrical continuity testing, achieving faster and more accurate detection.
3Reliability
If thermographic inspection is applied to detect joint failures, then detection accuracy improves, but additional equipment and process steps are required
Solution Approach 1:
The patent introduces thermal energy as an intermediary to reveal joint failures. By applying heat to the semiconductor package and using the thermal response as a mediator, the inspection system detects TSV connection issues through temperature differences. This intermediary approach simplifies the detection mechanism compared to direct electrical or mechanical inspection of internal TSV joints.
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
Effectively detects joint failures by identifying temperature differences in thermographic images, allowing for timely identification and addressing of electrical disconnects in semiconductor die stacks, enhancing the reliability and performance of stacked semiconductor packages.
Implementation Method 1
Heat may be supplied to a bottom surface of the base substrate opposite to the lower semiconductor die
Implementation Method 2
A thermographic image of a top surface of the upper semiconductor die opposite to the base substrate may be obtained
Data Source
AI summary
A method of detecting a joint failure of a semiconductor die stack is provided. The method may include providing the semiconductor die stack including a base substrate, a lower semiconductor die stacked on the base substrate, and an upper semiconductor die stacked on the lower semiconductor die opposite to the base substrate. The lower semiconductor die may include first through silicon vias (TSVs). Heat may be supplied to a bottom surface of the base substrate opposite to the lower semiconductor die. A thermographic image of a top surface of the upper semiconductor die opposite to the lower semiconductor die may be obtained. Whether the joint failure exists in the semiconductor die stack may be discriminated, with the thermographic image, based on a temperature difference between regions of the thermographic image corresponding with regions of the first TSVs.