Semiconductor Bump Structure for Reduced Height Mismatch
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Solution Overview
Problem
The height difference between signal bumps and heat transfer bumps in semiconductor devices can cause connection failures, reliability degradation, and damage during device connection.
Innovation Solution
The semiconductor device design includes conductive posts protruding at the lower portions of signal bumps, reducing the height difference between signal bumps and heat transfer bumps, with the heat transfer bumps being electrically insulated and wider than the signal bumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signal bumps and heat transfer bumps are formed with different heights, then the signal bumps can be electrically connected to the wiring pattern, but the height difference causes connection failures and reliability degradation during device connection
Solution Approach 1:
A conductive post is introduced as an intermediary element between the signal bump and the wiring pattern. The post extends into the recess formed in the passivation layer and substrate, providing a transition structure that eliminates the height difference between the signal bump and heat transfer bump, thereby preventing connection failures while maintaining electrical connectivity
Solution Approach 2:
The connection structure is segmented into multiple components: the heat transfer bump, the signal bump, the conductive post, and the recess. This segmentation allows each component to be optimized independently - the post can be designed to extend into the recess to match heights, while the bumps maintain their functional dimensions, resolving the height mismatch problem
2Temperature
If the heat transfer bump is made wider than the signal bump, then heat transfer efficiency is improved, but the wider bump may interfere with adjacent structures
Solution Approach 1:
The heat transfer bump is designed with a wider base portion that contacts the passivation layer, providing enhanced heat transfer area, while the upper portion is constrained within the recess to prevent interference with adjacent structures. This local variation in dimensions allows the bump to simultaneously achieve good heat transfer and spatial compatibility
Data Source
AI summary
A semiconductor device including a substrate, a wiring pattern in the substrate, a passivation layer on the substrate, the passivation layer and the substrate including a first recess penetrating a part of each of the passivation layer and the substrate and extending toward the wiring pattern, a post connected to the wiring pattern and including a first portion within the first recess and a second portion on the first portion and protruding from a top surface of the passivation layer, a signal bump including a seed layer on the post, a lower bump on the seed layer, and an upper bump on the lower bump, and a heat transfer bump apart from the signal bump, electrically insulated from the wiring pattern, and including another seed layer on the passivation layer, another lower bump on the another seed layer, and another upper bump on the another lower bump may be provided.