Post-passivation interconnect structure with dielectric isolation

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Solution Overview

Problem

Existing post-passivation interconnect (PPI) structures in semiconductor integrated circuits face limitations in flexible circuit routing, requiring additional layers to address signal integrity issues, which increases costs and reduces the process window.

Innovation Solution

The implementation of a PPI structure with a first upper connective layer featuring a supporting pad and a conductive channel, where a portion of the channel passes through the pad, and dielectric regions isolate them, enabling more flexible circuit routing and reducing the need for multiple layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing PPI structures are used with traditional routing methods, then manufacturing process is simpler, but circuit routing flexibility is insufficient and signal integrity issues arise

Engineering Contradiction:

Improvecircuit routing flexibilityVSAvoidPPI layer structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the PPI structure into distinct functional layers: a first upper connective layer with conductive channels for signal routing, a second upper connective layer with landing pads for connections, and an upper intermediate layer with vias for vertical interconnections. This segmentation enables flexible circuit routing while maintaining manageable complexity through clear functional separation of each layer.

Inventive Principle:

Principle #1Segmentation

2Reliability

If more PPI layers are added to improve routing area and signal integrity, then signal integrity improves, but manufacturing cost increases and process window decreases

Engineering Contradiction:

Improvesignal integrityVSAvoidmanufacturing cost and process window

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent designs each PPI layer to serve multiple functions: the first upper connective layer provides both signal routing and structural support, the second upper connective layer serves as both connection terminal and protective overlay, and the upper intermediate layer provides both mechanical support and electrical interconnection pathways. This multi-functionality reduces the total number of layers needed while maintaining signal integrity, thereby lowering manufacturing cost and expanding process window.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10068867B2Post-passivation interconnect structure and methods thereof

Publication Date: 2018.09.04 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method includes providing a die including a substrate and a bonding pad over the substrate, forming a connective layer over the die, and forming the landing pad over the connective layer. The forming the connective layer includes depositing a dielectric layer of a dielectric material over the die and patterning the dielectric layer. The patterning the dielectric layer includes forming a supporting pad area and forming a conductive channel area. A portion of the conductive channel area passes at least partially through the supporting pad area. At least one dielectric region interpose the portion of the conductive channel area and the supporting pad area. The forming the connective further includes filling the supporting pad area and the conductive channel area with a conductive material. The supporting pad area of the conductive material forms a supporting pad. The conductive channel area of the conductive material forms a conductive channel.