Chip Package Light Shielding Passivation Layer Side Surface Protection
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Solution Overview
Problem
The challenge in semiconductor chip packaging is the invasion of moisture through the side surfaces of chip packages, leading to internal circuit oxidation and reliability issues due to the lack of passivation on these surfaces, which affects the yield rate and functionality of the chips.
Innovation Solution
A chip package design that includes a light shielding passivation layer extending to cover the side surfaces of the chip, using materials like epoxy resin, and a method of manufacturing where the passivation layer is formed underneath the second surface and extends into the carrier substrate to cover the side surfaces, preventing moisture and light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wafer is cut into independent chip packages after standard passivation, then the manufacturing process is simple and efficient, but the side surfaces remain exposed to moisture causing internal circuit oxidation and reliability degradation
Solution Approach 1:
The passivation layer is extended from the traditional two-dimensional planar coverage to three-dimensional coverage by making it wrap around and cover the side surfaces of the chip package. This dimensional extension ensures that moisture blocking is provided not only on the top and bottom surfaces but also on the vertical side surfaces, thereby protecting internal circuits from oxidation while maintaining manufacturing efficiency.
Solution Approach 2:
A thin film passivation layer is formed that conformally covers the side surfaces of the chip package. This flexible thin film structure adapts to the three-dimensional geometry of the chip package, providing continuous moisture and light blocking protection across all exposed surfaces including the vertical side walls, without requiring complex rigid encapsulation structures.
2Ease of manufacture
If the side surfaces are left exposed for manufacturing simplicity, then the production process remains straightforward, but moisture invasion causes internal circuit oxidation and silicon via damage
Solution Approach 1:
The passivation layer is formed to cover the side surfaces before the chip package is fully assembled and sealed. This preliminary action of extending passivation to side surfaces during the manufacturing process prevents moisture invasion from the outset, protecting internal circuits and silicon vias from oxidation and damage before the product is deployed, thereby maintaining manufacturing simplicity while eliminating the harmful effect.
3Object-affected harmful factors
If additional passivation layers are added to cover side surfaces, then moisture and light blocking is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The passivation layer is designed to serve multiple functions simultaneously: it provides electrical insulation, moisture blocking, and light shielding protection. By making the single passivation layer wrap around and cover the side surfaces, it performs all these protective functions in one structure, preventing moisture invasion and light interference without requiring separate additional layers for each function, thereby maintaining manufacturing process simplicity.
4Productivity
If the passivation layer is extended to cover side surfaces, then yield rate and reliability are improved, but the manufacturing complexity increases
Solution Approach 1:
The passivation layer is extended from planar two-dimensional coverage to three-dimensional coverage by wrapping around the side surfaces. This dimensional extension protects internal circuits and silicon vias from moisture and light damage, directly improving chip yield rate and reliability without requiring multiple separate processing steps or complex assembly operations.
Solution Approach 2:
A conformal thin film passivation structure is formed that naturally adapts to the three-dimensional shape of the chip package, providing continuous protection on all surfaces. This flexible thin film approach achieves comprehensive moisture and light blocking with a single manufacturing process, improving yield rate without significantly increasing manufacturing complexity.
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 solution effectively blocks moisture and light from entering the chip package, enhancing the reliability and yield rate by protecting the internal circuits and sensing layers, and maintaining the integrity of the chip package.
Implementation Method 1
the light shielding passivation layer is disposed under the second surface and extends into the carrier substrate to cover the side surface of the chip
Implementation Method 2
blocks moisture and light from entering the chip package, enhancing the reliability and yield rate by protecting the internal circuits and sensing layers
Data Source
AI summary
A chip package includes a chip, a dam layer, a carrier substrate and a light shielding passivation layer. The chip has a first surface and a second surface opposite to the first surface, and a side surface is disposed between the first surface and the second surface. The dam layer is disposed on the first surface, and the carrier substrate is disposed on the dam layer. The light shielding passivation layer is disposed under the second surface and extended into the carrier substrate to cover the side surface of the chip.