Filling Member Thermal Expansion Management in Semiconductor Through Holes
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Solution Overview
Problem
The existing semiconductor devices face reliability issues due to thermal shrinkage of electrically conductive adhesives used in through holes, which can cause disconnection between electrode pads and redistribution layers, especially in power device-equipped fan-out wafer-level packages intended for millimeter wave communication applications.
Innovation Solution
A semiconductor device design that fills through holes with a filling member having a lower coefficient of thermal expansion than the electrically conductive adhesive, using a filler-containing resin with a binder and filler materials like silicon oxide or alumina, ensuring the electrode pad remains connected to the redistribution layer by inhibiting thermal shrinkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrically conductive adhesive is used as filling member, then electrical connectivity is maintained, but high coefficient of thermal expansion causes thermal shrinkage and disconnection
Solution Approach 1:
The filling member is designed as a composite material combining conductive fillers (such as metal particles, carbon, or conductive oxides) with a resin matrix and inorganic filler particles. This composite structure maintains electrical conductivity through the conductive filler network while the inorganic fillers provide low thermal expansion characteristics, achieving both electrical connectivity and dimensional stability.
Solution Approach 2:
The patent applies different filler materials and concentrations in different regions or layers of the filling member to optimize local properties. The composite structure provides different functional characteristics in different zones, with conductive fillers ensuring electrical connectivity and inorganic fillers providing dimensional stability, achieving both requirements simultaneously.
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
This design effectively prevents disconnection between the electrode pad and the redistribution layer, enhancing the reliability of semiconductor devices by managing thermal expansion and maintaining electrical connectivity.
Implementation Method 1
a filling member with which the through hole is filled, the filling member being lower in coefficient of thermal expansion than the electrically conductive adhesive
Implementation Method 2
an electrically conductive adhesive disposed on a side of the second face of the semiconductor substrate, and electrically connected to the electrode pad via the electrically conductive film; a heat radiating member bonded to the second face of the semiconductor substrate with the electrically conductive adhesive
Implementation Method 3
an electrically conductive film covering an inner wall of the through hole, and electrically connected to the electrode pad
Implementation Method 4
a heat radiating member bonded to the second face of the semiconductor substrate with the electrically conductive adhesive
Data Source
AI summary
A semiconductor device includes: a semiconductor substrate; an electrode pad disposed over a first face of the semiconductor substrate; a redistribution layer electrically connected to the electrode pad; a through hole disposed in the semiconductor substrate so as to extend from a second face opposite to the first face of the semiconductor substrate to the electrode pad; an electrically conductive film covering an inner wall of the through hole, and electrically connected to the electrode pad; an electrically conductive adhesive disposed on a side of the second face of the semiconductor substrate, and electrically connected to the electrode pad via the electrically conductive film; a heat radiating member bonded to the second face of the semiconductor substrate with the electrically conductive adhesive; and a filling member with which the through hole is filled, the filling member being lower in coefficient of thermal expansion than the electrically conductive adhesive.