Semiconductor Die Encapsulation Layout for Wafer Warpage Reduction

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Solution Overview

Problem

Semiconductor packages experience warpage due to the mismatch in thermal expansion coefficients between the encapsulating material and the semiconductor material, exacerbated by reduced die ratios, leading to handling difficulties in downstream processes.

Innovation Solution

Employing a mold frame with protruded partitions aligned with scribe lines to reduce the volume of encapsulating material, using low surface energy coatings, and incorporating a release film to mitigate warpage by displacing and reducing the amount of encapsulating material during the molding process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the volume of encapsulating material is reduced to minimize warpage, then wafer warpage is reduced and handling is improved, but the protective coverage and structural integrity may be compromised

Engineering Contradiction:

Improvewafer warpageVSAvoidencapsulating material volume

Core Design Contradiction:

Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The mold frame is divided into multiple partitions that create separate cavities, allowing selective filling of encapsulating material in specific regions while leaving other regions partially filled or empty, thus reducing overall material volume while maintaining necessary protection

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the semiconductor die assembly receive different amounts of encapsulating material based on local requirements - areas prone to warpage receive less material while critical areas maintain adequate coverage, achieving non-uniform distribution optimized for warpage reduction

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If protruded partitions are used to displace encapsulating material, then warpage is reduced and singulation is facilitated, but the mold frame complexity increases

Engineering Contradiction:

Improvewafer warpageVSAvoidmold frame structure

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The mold frame is segmented into multiple partitions that align with scribe lines, creating a structured framework that systematically manages encapsulating material distribution and facilitates subsequent singulation operations

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Protruded partitions act as intermediary structures between the mold frame and the semiconductor die assembly, mediating the displacement of encapsulating material to reduce warpage while maintaining processability

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If low surface energy coatings and release films are employed to reduce encapsulating material adhesion, then warpage mitigation is improved and handling is facilitated, but the process complexity and cost increase

Engineering Contradiction:

Improvewarpage mitigationVSAvoidmolding process steps

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Release films serve as intermediary layers between the mold frame and the encapsulating material, preventing excessive adhesion and facilitating easy release while reducing warpage through controlled material displacement

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The surface energy of the mold frame is modified through low surface energy coatings, changing the interaction parameters between the mold and encapsulating material to reduce adhesion forces and minimize warpage-induced sticking

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Reduces wafer warpage, improves handling during grinding, and facilitates efficient singulation of semiconductor die assemblies by minimizing encapsulating material, thereby enhancing process yield and reducing non-uniformity.

Implementation Method 1

mismatch in thermal expansion coefficients between the encapsulating material and the semiconductor material

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

using low surface energy coatings

Methodology Applied

Scientific EffectSurface energy: Surface Tension

Data Source

PatentUS12512332B2Encapsulation warpage reduction for semiconductor die assemblies and associated methods and systems

Publication Date: 2025.12.30 MICRON TECHNOLOGY INC

AI summary

Encapsulation warpage reduction for semiconductor die assemblies, and associated methods and systems are disclosed. In one embodiment, a semiconductor die assembly includes an interface die, a stack of semiconductor dies attached to a surface of the interface die, where the stack of semiconductor dies has a first height from the surface. The semiconductor die assembly also includes an encapsulant over the surface and surrounding the stack of semiconductor dies, where the encapsulant includes a sidewall with a first portion extending from the surface to a second height less than the first height and a second portion extending from the second height to the first height. Further, the first portion has a first texture and the second portion has a second texture different from the first texture.