Semiconductor Package Alignment Patterns for Thick Insulation Layers
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving accurate alignment and reliable connection of semiconductor packages due to limitations in miniaturization and integration density, requiring improved alignment methods for efficient mounting on boards.
Innovation Solution
The semiconductor package incorporates a redistribution structure with a pad insulation layer and alignment patterns extending into and away from the layer, functioning as an alignment mark or key, enhancing alignment efficiency and reliability during mounting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick pad insulation layer is used to ensure electrical isolation, then insulation reliability is improved, but alignment mark visibility and alignment precision deteriorate
Solution Approach 1:
The alignment pattern extends in the vertical dimension by protruding from the pad insulation layer surface. This three-dimensional structure allows the alignment mark to remain visible and accessible for alignment operations even when buried beneath or alongside a thick pad insulation layer, thus maintaining alignment precision while allowing the insulation layer to be sufficiently thick for electrical isolation.
Solution Approach 2:
The alignment pattern acts as an intermediary structure between the pad insulation layer and the external alignment system. By providing a dedicated alignment feature that extends through or beyond the insulation layer, it mediates the conflict between needing thick insulation for electrical isolation and requiring visible alignment marks for precise positioning.
2Ease of manufacture
If the alignment pattern is fully embedded in the pad insulation layer, then manufacturing simplicity is improved, but alignment mark efficiency and detection ease deteriorate
Solution Approach 1:
The alignment pattern utilizes the vertical dimension by extending protrusions from the pad insulation layer surface. This partial embedding approach maintains manufacturing simplicity compared to completely separate structures, while the protruding portions significantly improve alignment mark visibility and detection efficiency for positioning operations.
3Productivity
If the semiconductor package is miniaturized to increase integration density, then productivity and integration density are improved, but alignment tolerance and connection reliability worsen
Solution Approach 1:
The alignment pattern is segmented into multiple protrusions distributed around the pad insulation layer perimeter. This segmentation provides multiple alignment reference points, increasing the robustness of alignment operations and allowing for better tolerance compensation in miniaturized packages where alignment margins are reduced.
Solution Approach 2:
The alignment pattern concentrates alignment functionality at specific localized regions (the protruding portions) rather than requiring the entire pad insulation layer to serve as an alignment reference. This local quality approach enhances alignment mark efficiency in miniaturized packages where space and tolerance are constrained.
Data Source
AI summary
A semiconductor package including: a first redistribution structure; a semiconductor chip on the first redistribution structure; a pad insulation layer on a lower surface of the first redistribution structure; a conductive pad extending into a lower surface of the pad insulation layer and electrically connected to the first redistribution structure; and a plurality of alignment patterns on an edge of the pad insulation layer, each of the plurality of alignment patterns including a first portion extending into a lower surface of the pad insulation layer and a second portion extending away from the lower surface of the pad insulation layer.