Semiconductor Shielding Layer Layout to Prevent Bond Pad Shorting
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Solution Overview
Problem
Semiconductor devices with exposed components face challenges in forming a shielding layer due to potential shorting with existing EMI shielding methods, making it impractical to reduce electromagnetic interference effectively.
Innovation Solution
A method involving etching a portion of the bond pad adjacent to the lateral surface to create a gap, filling the gap with a filler, and applying a shielding layer to the back side of the substrate, thereby avoiding direct contact and shorting with the bond pads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a uniformly spread coating or metal cover is applied around the outer periphery as a shielding layer, then EMI shielding effectiveness is improved, but components exposed to the external environment (e.g., bond pads) may be shorted with the shielding layer
Solution Approach 1:
The bond pad structure is segmented by etching a portion of it adjacent to the lateral surface to form a gap. This segmentation separates the bond pad into two parts: one that remains electrically connected to the device and another that is isolated near the lateral surface, preventing contact with the shielding layer while maintaining electrical functionality.
Solution Approach 2:
A filler material is introduced as an intermediary substance to fill the gap between the bond pad and the lateral surface. This filler acts as a physical barrier that prevents direct contact between the bond pad and the shielding layer, thereby avoiding shorting while allowing the shielding layer to be applied uniformly.
2Ease of operation
If bond pads extend to the lateral surface of the substrate, then electrical connectivity and functionality are maintained, but direct contact with the shielding layer causes shorting
Solution Approach 1:
The bond pad is segmented by creating a gap through etching, which separates the electrically functional portion from the portion that would contact the shielding layer. This segmentation maintains electrical connectivity through the remaining bond pad structure while preventing harmful contact with the shield.
Solution Approach 2:
The problematic portion of the bond pad that would cause shorting is effectively extracted or removed by etching it away adjacent to the lateral surface. This extraction eliminates the shorting risk while preserving the essential electrical connectivity functions of the bond pad.
Data Source
AI summary
A method for forming a shielding layer on a semiconductor device is disclosed. The semiconductor device comprises a bond pad formed on a front side of a substrate and extends to a first lateral surface of the substrate. The method comprises: etching a portion of the bond pad adjacent to the first lateral surface, to form a gap between the bond pad and the first lateral surface; attaching a filler onto the bond pad to fill the gap; and applying a shielding layer to a back side of the substrate.