Redistribution Layer Pad Extension for Die Shift Alignment
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Solution Overview
Problem
In chip first packages, die shift during encapsulation layer formation causes electrical terminals to be misaligned, making it difficult to connect the chip to overlying electronic components, leading to reduced yield.
Innovation Solution
The electronic device package includes a redistribution layer (RDL) with conductive pads having extension portions and a dielectric layer, where the conductive via connection region is closer to the center of curvature of the extension portion than the pad portion, allowing for accurate alignment and connection despite die shift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional chip first package is used, then the manufacturing process is simple, but the die shift causes misalignment between electrical terminals and reduces yield
Solution Approach 1:
The extension portion is designed and formed in advance during RDL fabrication, before the encapsulation process occurs. This preliminary geometric adjustment ensures that even when die shift happens during encapsulation, the conductive via will still align properly with the extended pad area, thus maintaining alignment precision without complicating the overall manufacturing process
Solution Approach 2:
Instead of modifying the entire pad structure or using complex alignment systems, the invention applies a localized geometric modification - extending only the specific portion of the conductive pad that will compensate for the expected die shift. This local quality change maintains manufacturing simplicity while improving alignment precision at the critical connection point
2Productivity
If die shift is allowed to occur during encapsulation, then the encapsulation process is straightforward, but the electrical terminals are misaligned from their predetermined region
Solution Approach 1:
The invention accepts that die shift will occur during encapsulation but converts this harmful effect into a benefit by designing the extension portion to anticipate and compensate for the shift. The pad extension is positioned such that when the die shifts in the expected direction, the conductive via aligns with the extended area rather than the original pad center, thus maintaining connection accuracy without slowing down the encapsulation process
Solution Approach 2:
The extension portion is pre-formed during RDL fabrication before encapsulation takes place. This preliminary geometric adjustment ensures that when die shift occurs during the straightforward encapsulation process, the alignment is already compensated for, maintaining terminal alignment precision while preserving encapsulation efficiency
Data Source
AI summary
An electronic device package includes an encapsulated electronic component, a redistribution layer (RDL) and a conductive via. The RDL is disposed above the encapsulated electronic component. The RDL includes a circuit layer comprising a conductive pad including a pad portion having a curved edge and a center of curvature, and an extension portion protruding from the pad portion and having a curved edge and a center of curvature. The circuit layer further includes a dielectric layer above the RDL. The conductive via is disposed in the dielectric layer and connected to the conductive pad of the RDL. A center of the conductive via is closer to the center of curvature of the edge of the extension portion than to the center of curvature of the edge of the pad portion.