Semiconductor Underfill Dam Structure for Passive Component Protection

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Solution Overview

Problem

As semiconductor devices and substrates shrink in size, the integration density increases, leading to a challenge in preventing physical contact between underfill material and passive components, which can cause delamination due to mismatched thermal expansion coefficients, and results in damage to the semiconductor device.

Innovation Solution

A dam structure is formed around the semiconductor device on the substrate to confine the underfill material, preventing it from contacting passive components and allowing for reduced size without damage, using a sacrificial material like polymer or epoxy that can be easily removed after curing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the semiconductor device size is reduced to increase integration density, then the component density and functionality are improved, but the risk of underfill material contacting passive components increases, causing delamination and device damage

Engineering Contradiction:

Improveintegration densityVSAvoiddevice reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A dam structure is introduced as an intermediary element between the underfill material and passive components. This dam structure physically blocks the underfill material from reaching and contacting the passive components, thereby preventing delamination and device damage while allowing the semiconductor device to be miniaturized for higher integration density

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The packaging structure is segmented into distinct regions by the dam structure, which divides the space around the semiconductor die into a confined underfill region and a protected passive component region. This segmentation isolates the underfill material within specific boundaries, preventing it from migrating to harmful areas

Inventive Principle:

Principle #1Segmentation

2Area of stationary object

If the device size is reduced, then the footprint is minimized, but the underfill material has less space to be contained, increasing the risk of spilling and contacting passive components

Engineering Contradiction:

Improvedevice footprintVSAvoidunderfill material spilling

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The dam structure acts as a flexible containment boundary that defines the exact space needed for underfill material. By creating precise geometric boundaries, the dam structure ensures that even in miniaturized devices with limited space, the underfill material remains confined and cannot spill onto passive components

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The dam structure is formed prior to underfill material application, pre-establishing the containment boundaries. This preliminary action ensures that when the underfill material is applied, it is immediately constrained within the defined space, preventing spilling before it can occur

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11901255B2Semiconductor device and method of forming the same

Publication Date: 2024.02.13 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method of forming a semiconductor device includes attaching a first semiconductor device to a first surface of a substrate; forming a sacrificial structure on the first surface of the substrate around the first semiconductor device, the sacrificial structure encircling a first region of the first surface of the substrate; and forming an underfill material in the first region.