Silicon Package Substrate Through Electrode Connection Reinforcement
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Solution Overview
Problem
The existing silicon substrates for semiconductor packages face issues with disconnection between through electrodes and thin film wiring in cavities due to irregularities and differential thermal expansion, leading to potential disconnections.
Innovation Solution
The silicon substrate incorporates a reinforced conductor connected to the thin film wiring, a metal bump or solder re-flow part to fill the space in the through hole, or wire bonding to form a robust connection between the through electrode and the thin film wiring, ensuring mechanical strength and preventing disconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the end part of the through electrode is recessed into the through hole from the bottom surface of the cavity, then the connection part is formed, but the thickness of the thin film wiring becomes small leading to disconnection
Solution Approach 1:
The patent applies preliminary action by forming a protrusion on the inner wall of the through hole before forming the thin film wiring. This protrusion serves as a pre-prepared structural feature that ensures adequate wiring thickness and prevents disconnection, addressing the reliability issue before the actual connection is made.
Solution Approach 2:
The patent applies local quality by creating a localized protrusion structure at specific positions within the through hole where connections are needed. This localized structural modification ensures that the thin film wiring has sufficient thickness only at critical connection points, rather than uniformly throughout, thus preventing disconnection while maintaining manufacturing precision.
2Manufacturing precision
If the end part of the through electrode protrudes from the bottom surface of the cavity, then the connection part is formed, but distortion due to differential thermal expansion concentrates on the protruding part leading to disconnection
Solution Approach 1:
The patent applies local quality by creating a localized protrusion structure at specific positions within the through hole. This localized structural feature distributes and mitigates the concentration of thermal expansion distortion, preventing disconnection while maintaining positioning precision of the through electrode end part.
Solution Approach 2:
The patent applies preliminary action by pre-forming the protrusion structure before thermal processing. This pre-prepared structural feature anticipates and compensates for upcoming thermal expansion effects, ensuring structural stability is maintained even before the actual thermal stress is applied.
3Manufacturing precision
If a flattening process by polishing is applied to the bottom surface of the cavity, then surface flatness is improved, but the process cannot be applied to the bottom surface of the cavity
Solution Approach 1:
The patent applies the taking out principle by extracting the polishing process from the bottom surface of the cavity. Instead of attempting to polish the inaccessible bottom surface, the invention removes this impossible step from the manufacturing sequence and achieves the necessary flatness through alternative means (the protrusion structure), thus maintaining manufacturing precision without the impossible polishing step.
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 reinforced connections provide enhanced mechanical strength and prevent disconnections, ensuring reliable electrical contact and reduced failure rates in the semiconductor package.
Implementation Method 1
a through electrode 14 formed by filling a through hole 12 that passes through a silicon substrate 10 in the direction of a thickness with a plating
Implementation Method 2
A thin film wiring 20 formed on a bottom surface 16B of the cavity by sputtering or a deposition
Implementation Method 3
A thin film wiring 20 formed on a bottom surface 16B of the cavity by sputtering or a deposition
Data Source
AI summary
In a silicon substrate for a package, a through electrode is provided with which a through hole passing through from a bottom surface of a cavity for accommodating a chip of an electronic device to a back surface of the substrate is filled. An end part of the through electrode in the bottom surface side of the cavity has a connection part to a wiring that forms an electric circuit including the chip of the electronic device. The silicon substrate for a package is characterized in that (1) a thin film wiring is included as the wiring and the connection part is reinforced by a conductor connected to the thin film wiring and/or (2) a wire bonding part is included as the wiring and the connection part is formed by wire bonding the end part of the through electrode in the bottom surface side of the cavity.