Wafer-Level Chip Encapsulation Portions for Moisture and Damage Protection

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Solution Overview

Problem

Conventional wafer-level packaging chips are prone to damage during handling and moisture ingress due to their poor durability and thermal expansion coefficient differences, leading to functional degradation.

Innovation Solution

The solution involves forming encapsulation portions on predetermined areas of the wafer-level packaging chip and its sides through passivation, using polymer or metal, to prevent damage and moisture ingress, involving steps like bonding a protection cap to a device substrate, bevel-cutting, and full dicing after passivation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wafer-level packaging is used to achieve compactness and high-performance, then device size is reduced and performance is improved, but chip durability deteriorates and moisture resistance is poor

Engineering Contradiction:

Improvedevice compactness and performanceVSAvoidchip durability and moisture resistance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Encapsulation portions are formed on the device substrate before the dicing process. This preliminary encapsulation protects the chip edges and surfaces from damage and moisture ingress that would otherwise occur during handling and after dicing, thereby improving reliability without compromising the compact wafer-level packaging design

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Encapsulation portions are selectively formed only on predetermined areas of the device substrate where edges and surfaces are exposed. This localized encapsulation provides targeted protection against moisture and damage only where needed, rather than encapsulating the entire device, thus maintaining the benefits of compact wafer-level packaging while improving reliability at critical locations

Inventive Principle:

Principle #3Local quality

2Productivity

If full dicing is performed to separate individual chips, then chip production is achieved, but chip edges become vulnerable to damage and moisture ingress

Engineering Contradiction:

Improvechip production capabilityVSAvoidchip damage and moisture ingress

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

Encapsulation portions are formed on the device substrate before the dicing process separates individual chips. This preliminary protective action ensures that when chips are cut apart, the edges and surfaces are already protected from damage and moisture ingress that would otherwise occur during and after the dicing process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Encapsulation portions act as a protective barrier formed beforehand on the chip edges and surfaces. This cushioning protection is in place before chips undergo handling and testing after dicing, preventing mechanical damage and moisture ingress at the vulnerable cut edges

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If protection cap is bonded to device substrate, then circuit module is protected, but thermal expansion coefficient difference causes gaps that allow moisture ingress

Engineering Contradiction:

Improvecircuit module protectionVSAvoidmoisture ingress through gaps

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Encapsulation portions are selectively formed on the device substrate at locations where gaps exist between the protection cap and substrate. This localized encapsulation provides targeted moisture barriers at the specific areas where thermal expansion gaps create vulnerability, complementing the protection cap's function while addressing its limitation

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The packaging structure combines multiple protective elements: the protection cap made of one material and encapsulation portions made of different materials (such as organic encapsulants or metal) formed on the device substrate. This composite approach leverages the strengths of each material to provide both mechanical protection and moisture barrier functionality

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS7906841B2Wafer level incapsulation chip and encapsulation chip manufacturing method

Publication Date: 2011.03.15 SAMSUNG ELECTRONICS CO LTD

AI summary

A wafer level encapsulation chip and an encapsulation chip manufacturing method. The encapsulation chip includes a device substrate, a circuit module mounted on the device substrate, a bonding layer deposited on a predetermined area of the device substrate, a protection cap forming a cavity over the circuit module and bonded to the device substrate by the bonding layer and encapsulation portions formed on predetermined areas of the bonding layer and the protection cap. Thus, the present invention can minimize damages to a chip upon chip handling and prevent moisture from being introduced into the inside of the chip.