Thermosetting Wafer Support for TSV Handling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current through-silicon via (TSV) processing methods lack adequate mechanical protection for fragile thinned wafers, leading to potential mechanical damage during handling and processing.

Innovation Solution

A method involving the use of a permanent cured thermosetting material as a substrate support, which provides mechanical rigidity and stiffness, allowing for the temporary attachment and subsequent detachment of the device wafer during TSV processing, utilizing reflowed solder bumps and a thermosetting material to create a planar bonding surface, and enabling the formation of TSVs with enhanced protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If thinned device wafers are handled without support systems, then handling complexity is reduced, but mechanical damage risk increases

Engineering Contradiction:

Improvehandling complexityVSAvoidmechanical damage risk

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces a temporary support wafer as an intermediary carrier that holds the thinned device wafer during TSV processing. This mediator provides the necessary mechanical support to prevent damage while enabling successful processing, and is subsequently removed after its protective function is completed.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If permanent cured thermosetting material is used as substrate support, then mechanical protection is improved, but detachment difficulty increases

Engineering Contradiction:

Improvemechanical protectionVSAvoiddetachment difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies a release coating to the temporary support wafer before attaching the device wafer. This preliminary action ensures that detachment can be easily performed later by simply heating the support wafer to melt the temporary adhesive, without requiring forceful separation that could damage the device.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If thermoplastic adhesive is used for temporary bonding, then detachment ease is improved, but mechanical protection is reduced

Engineering Contradiction:

Improvedetachment easeVSAvoidmechanical protection

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent employs a composite support structure consisting of a rigid temporary support wafer combined with a temporary adhesive layer. This composite provides both the mechanical strength needed to protect thinned wafers during processing and the ease of detachment through thermal release, combining properties that individually would be contradictory.

Inventive Principle:

Principle #40Composite materials

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

This approach effectively protects the wafers from mechanical damage, ensures successful TSV processing, and facilitates the integration of wafers into 3D packaging structures with improved handling and integration capabilities.

Implementation Method 1

a permanent cured thermosetting material as a substrate support

Methodology Applied

Scientific EffectCuring:

Implementation Method 2

utilizing reflowed solder bumps and a thermosetting material to create a planar bonding surface

Methodology Applied

Scientific EffectReflow:

Implementation Method 3

a light-to-heat conversion (LTHC) release coating. After TSV processing is completed, laser radiation is applied through the glass carrier wafer to the LTHC layer, thus weakening it

Methodology Applied

Scientific EffectLight-to-heat conversion:

Data Source

PatentUS9252111B2Method for handling very thin device wafers

Publication Date: 2016.02.02 GOOGLE LLC

AI summary

A structure and method of handling a device wafer during through-silicon via (TSV) processing are described in which a device wafer is bonded to a temporary support substrate with a permanent thermosetting material. Upon removal of the temporary support substrate a planar frontside bonding surface including a reflowed solder bump and the permanent thermosetting material is exposed.