Mold Array Process Pre-cut Grooves for Substrate Edge Encapsulation

Solution Overview

Problem

Conventional Mold Array Process (MAP) methods in semiconductor packaging fail to fully encapsulate the cut edges of substrate units, leading to exposure of metal traces and core layers, which results in moisture diffusion and reliability issues, as well as potential damage during singulation processes.

Innovation Solution

The MAP method involves forming pre-cut grooves with a width greater than the scribe lines on a substrate strip, allowing the encapsulant to fill and encapsulate the cut edges, thereby protecting them during singulation and improving moisture resistance and package reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional MAP method is used to encapsulate substrate units, then mass production cost is reduced, but cut edges of substrate units are exposed leading to moisture diffusion and reliability issues

Engineering Contradiction:

Improvemoisture resistanceVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by forming pre-cut grooves on the substrate strip before the encapsulation process. These grooves are created in advance to define where the encapsulant will flow and encapsulate the cut edges. This preliminary structuring ensures that when singulation occurs, the encapsulant is already positioned to protect the cut edges, preventing moisture diffusion and improving reliability without adding complex post-processing steps

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies segmentation by dividing the substrate strip into individual substrate units with pre-cut grooves between them. These grooves create distinct segments that allow the encapsulant to fill and encapsulate each cut edge separately. This segmentation approach enables the encapsulation process to effectively protect each individual cut edge while maintaining the efficiency of mass production

Inventive Principle:

Principle #1Segmentation

2Reliability

If substrate units are singulated along scribe lines without pre-cut grooves, then individual semiconductor packages are obtained, but cut edges are exposed and vulnerable to damage

Engineering Contradiction:

Improvepackage integrityVSAvoidcut edge protection

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by forming pre-cut grooves on the substrate strip before the encapsulation process. These grooves are created in advance to define where the encapsulant will flow and encapsulate the cut edges. This preliminary structuring ensures that when singulation occurs, the encapsulant is already positioned to protect the cut edges, preventing moisture diffusion and improving reliability without adding complex post-processing steps

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies preliminary anti-action by creating pre-cut grooves that prevent the harmful effect of exposed cut edges before singulation occurs. The grooves are designed to guide the encapsulant to the cut edges, creating a protective barrier in advance that counteracts the potential for moisture diffusion and mechanical damage during the singulation process

Inventive Principle:

Principle #9Preliminary anti-action

3Ease of manufacture

If encapsulant is formed over scribe lines, then substrate units are encapsulated, but encapsulant must be removed during singulation exposing cut edges

Engineering Contradiction:

Improveencapsulation efficiencyVSAvoidcut edge protection

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by forming pre-cut grooves on the substrate strip before the encapsulation process. These grooves are created in advance to define where the encapsulant will flow and encapsulate the cut edges. This preliminary structuring ensures that when singulation occurs, the encapsulant is already positioned to protect the cut edges, preventing moisture diffusion and improving reliability without adding complex post-processing steps

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by creating pre-cut grooves at specific locations where cut edges will be exposed. The grooves are strategically positioned to provide localized encapsulation exactly where needed - at the cut edges - while the rest of the substrate unit maintains its original encapsulation. This targeted approach ensures cut edge protection without requiring removal of encapsulant from other areas

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8361841B2Mold array process method to encapsulate substrate cut edges

Publication Date: 2013.01.29 WALTON ADVANCED ENG INC

AI summary

Disclosed is a mold array process (MAP) method to encapsulate cut edges of substrate units. A substrate strip includes a plurality of substrate units arranged in a matrix. Scribe lines are defined between adjacent substrate units and at the peripheries of the matrix where pre-cut grooves are formed along the scribe lines with a width greater than the width of the scribe lines. An encapsulant is formed on the matrix of the substrate strip to continuously encapsulate the substrate units and the scribe lines to enable the encapsulant to fill into the pre-cut grooves to further encapsulate the cut edges of the substrate units. The cut edges of the substrate units are still encapsulated by the encapsulant even after singulation processes where substrate units are singulated into individual semiconductor packages to prevent the exposure of the plated traces of the substrate units to enhance the moisture resistance capability of the semiconductor packages.