Dielectric Partitioning for Electrical Isolation in Semiconductor Substrates
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Solution Overview
Problem
The miniaturization of semiconductor devices poses a challenge in maintaining electrical performance without increasing package size, particularly in chip scale packages where electrical shorting can occur between active regions and solder contacts.
Innovation Solution
The use of dielectric partitions that extend through the substrate from the major surface to the backside, electrically isolating active regions and sidewalls, and featuring interlocking portions to prevent physical separation and enhance mechanical robustness, allowing for reduced package size and preventing electrical shorting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If chip scale packages are miniaturized to reduce package size, then the device dimensions are reduced, but electrical shorting between active regions and solder contacts becomes more likely
Solution Approach 1:
The substrate is divided into multiple electrically isolated parts by introducing dielectric partitions that extend through the substrate thickness. These partitions create separate regions (first part with active region, second part with sidewall) that are electrically isolated from each other, preventing solder from creating electrical shorts between active regions and the substrate sidewall.
Solution Approach 2:
A dielectric partition material is introduced as an intermediary between the active region and the sidewall. This dielectric material acts as an electrical barrier that prevents direct electrical contact between the conductive active region and the sidewall, thereby eliminating the risk of electrical shorting while allowing the package to remain miniaturized.
2Reliability
If dielectric partitions are introduced to electrically isolate active regions from sidewalls, then electrical isolation is improved, but the device complexity increases
Solution Approach 1:
Instead of adding lateral complexity to isolate active regions, the solution extends the isolation structure through the thickness dimension of the substrate. The dielectric partitions extend from the major surface through to the backside, utilizing the vertical dimension to achieve electrical isolation without increasing the lateral footprint or planar complexity of the device.
Solution Approach 2:
The dielectric partition serves multiple functions simultaneously: it provides electrical isolation between active regions and sidewalls, acts as a mechanical barrier to prevent solder penetration, and can be configured with interlocking portions that provide structural support. This multi-functionality reduces the need for additional separate structures.
3Length of stationary object
If the substrate is thinned to reduce device size, then the overall dimensions are reduced, but mechanical strength and structural integrity are compromised
Solution Approach 1:
The substrate is segmented into multiple parts by the dielectric partitions, and interlocking portions are introduced at the interfaces between these parts. The interlocking portions include locking members received within openings, creating mechanical interlocks that prevent physical separation. This segmented design with interlocks maintains structural integrity even when the substrate is thinned.
Solution Approach 2:
The device structure becomes a composite of the substrate material and the dielectric partition material. The dielectric partitions act as reinforcement elements within the substrate, creating a composite structure that maintains or enhances mechanical strength while allowing the substrate to be thinned for miniaturization.
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5C
AI summary
A semiconductor device and a method of making the same. The device includes a substrate comprising a major surface and a backside. The device also includes a dielectric partition for electrically isolating a first part of the substrate from a second part of the substrate. The dielectric partition extends through the substrate from the major surface to the backside.