Stacked Semiconductor Dice Protection Layer Hardness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices with stacked layer structures are vulnerable to lateral mechanical stress and corrosive infiltration, leading to reliability and yield issues, especially when a single failed die causes device failure due to the stacking method used in manufacturing.
Innovation Solution
A semiconductor device with a base substrate, stacked dice electrically connected via a wiring layer, and a protection layer composed of resin layers of different hardness, along with a manufacturing method that includes testing dice, forming resin layers, and cutting the substrate to prevent mechanical stress and corrosive infiltration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semiconductor substrates are stacked in wafer form with through hole electrodes and conductive terminals, then electrical connection between stacked layers is achieved, but the device becomes vulnerable to lateral mechanical stress that can peel off the stacked layers
Solution Approach 1:
A resin layer is formed to cover the side surfaces of the stacked semiconductor substrates before final assembly, providing protective cushioning that prevents lateral mechanical stress from reaching the interfaces between stacked layers. This beforehand protection eliminates the peel-off vulnerability without requiring changes to the stacking structure itself.
Solution Approach 2:
A flexible resin layer is applied as a thin film covering the side surfaces of the stacked substrates. This flexible shell conforms to the stacked structure and provides mechanical protection against lateral stress, preventing the peeling of layers while maintaining the electrical connection integrity through the through hole electrodes.
2Reliability
If conventional manufacturing methods are used to stack semiconductor substrates, then device integration is achieved, but corrosive materials can infiltrate and deteriorate metal portions, reducing reliability and yield
Solution Approach 1:
A resin layer is formed as a protective thin film that completely covers the side surfaces of the stacked semiconductor substrates, creating a barrier that prevents corrosive materials such as chemical solutions or water from infiltrating and deteriorating the metal portions including conductive terminals and wiring.
Solution Approach 2:
The resin layer acts as an intermediary barrier between the external environment and the metal portions of the stacked substrates. This intermediate protective layer blocks corrosive materials from directly contacting the metal surfaces, thereby preventing deterioration while allowing the device to function normally.
3Productivity
If wafer form stacking is used for manufacturing, then production efficiency is maintained, but a single failed die causes complete device failure, reducing yield
Solution Approach 1:
The invention maintains wafer form stacking for manufacturing efficiency but introduces a protective resin layer that segments the failure modes. The resin layer protects individual stacked interfaces, allowing failed dies to be isolated without causing complete device failure, thereby improving yield while preserving productivity.
Data Source
AI summary
Semiconductor dice judged as good dice are stacked on a base substrate in which through holes and through hole electrodes are formed. Next, a protection layer to cover the semiconductor dice is formed. It is preferable that the protection layer is composed of a plurality of resin layers (a first resin layer and a second resin layer) that are different, in hardness from each other. Then, a conductive terminal that is connected with the through hole electrode is formed on a back surface of the base substrate. Next, the second resin layer and the base substrate are cut along predetermined dicing lines and separated into individual semiconductor devices in chip form. A process step of separation into the semiconductor devices is performed while each of the semiconductor dice is mounted on the base substrate in wafer form.