Stacked Semiconductor Package Grooves for Moisture-Resistant Encapsulation
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Solution Overview
Problem
Semiconductor packages face challenges in reliability due to delamination and moisture introduction, primarily caused by non-conductive layers protruding from lateral surfaces during the stacking and encapsulation process.
Innovation Solution
The introduction of grooves on semiconductor dies, filled with non-conductive layers, prevents these layers from protruding and enhances the encapsulation by the mold layer, thereby increasing the reliability of the semiconductor package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-conductive layers are used between stacked semiconductor dies, then electrical insulation and structural support are improved, but the non-conductive layers protrude from lateral surfaces causing delamination and moisture ingress
Solution Approach 1:
The protruding portions of the non-conductive layers are removed by forming grooves in the semiconductor dies that extend to the lateral surfaces. This extraction of the harmful protruding parts eliminates the cause of delamination and moisture ingress while preserving the essential function of the non-conductive layers in providing electrical insulation and structural support between stacked dies.
Solution Approach 2:
The grooves that remove the harmful protruding portions also serve as channels for the mold layer to fully encapsulate the non-conductive layers. This converts the potential harm of exposed non-conductive layer surfaces into a benefit by enabling complete encapsulation, which prevents moisture ingress and enhances package reliability.
2Reliability
If non-conductive layers are placed between stacked semiconductor dies, then electrical insulation is improved, but moisture can ingress through protruding surfaces
Solution Approach 1:
The grooves remove the protruding portions of non-conductive layers that would otherwise be exposed to moisture. By extracting these vulnerable surfaces, the patent eliminates the primary pathway for moisture ingress while maintaining the electrical insulation function of the non-conductive layers embedded within the stacked structure.
Solution Approach 2:
The grooves enable the mold layer to completely encapsulate the non-conductive layers, converting the potential vulnerability of exposed surfaces into a protective feature. This full encapsulation creates a moisture barrier that protects the electrical insulation layers from environmental degradation.
3Stability of the object's composition
If non-conductive layers are used for structural support in stacked packages, then mechanical stability is improved, but delamination occurs at protruding surfaces
Solution Approach 1:
The grooves extend to the lateral surfaces of the semiconductor dies, removing the protruding portions of the non-conductive layers. This extraction eliminates the stress concentration points and adhesion failure sites that cause delamination, while the grooves themselves provide new adhesion surfaces for the mold layer that enhance overall mechanical stability.
Solution Approach 2:
The grooves transform the delamination-prone protruding surfaces into encapsulated features. By enabling the mold layer to fully surround the non-conductive layers, the grooves convert potential failure points into reinforced structures, improving mechanical stability through complete encapsulation and new adhesion interfaces.
Data Source
AI summary
A semiconductor package includes a first semiconductor die, second semiconductor dies each of which has a width less than a width of the first semiconductor die and which are stacked on the first semiconductor die, a first non-conductive layer between the first semiconductor die and a lowermost second semiconductor die, and a second non-conductive layer between adjacent ones of the second semiconductor dies. Each of the second semiconductor dies includes a first substrate that has a first front surface and a first rear surface, a first interlayer dielectric layer that covers the first front surface, first through electrodes that penetrate the first substrate, and a first passivation layer that covers the first rear surface. A first groove is in the first passivation layer and a portion of the first substrate. The second non-conductive layer is within the first groove.