Semiconductor Bonding Layer Viscosity Control

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Solution Overview

Problem

The productivity of semiconductor device manufacturing is hindered by the need to adjust the viscosity of the bonding layer across various assembly processes, such as die bonding, wire bonding, and sealing, as excessive viscosity leads to bonding unevenness, microvoids, and misalignment, while insufficient viscosity results in weak bonding and voids.

Innovation Solution

The method involves controlling the viscosity of the bonding layer within specific ranges for each process by adjusting the composition and heat treatment of the bonding material, using a noncontact applicator to apply a bonding layer on the semiconductor element's rear surface, with preferred viscosities of 10 Pa·s or more for die bonding and 15000 Pa·s or less for wire bonding, and ensuring the viscosity does not exceed the upper limit in the sealing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the viscosity of the bonding layer is increased to improve bonding strength, then bonding strength is improved, but bonding unevenness and misalignment occur

Engineering Contradiction:

Improvebonding strengthVSAvoidbonding uniformity

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the viscosity of the bonding material within a specific range (10-15000 Pa·s) to simultaneously achieve adequate bonding strength and uniform bonding without excessive viscosity causing bonding unevenness or misalignment

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamics by adjusting the viscosity of the bonding material dynamically according to different assembly processes (die bonding, wire bonding, sealing), allowing the bonding layer to exhibit appropriate flow characteristics at each stage to ensure both strength and uniformity

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If the viscosity of the bonding layer is decreased to improve bonding uniformity, then bonding uniformity is improved, but bonding strength decreases

Engineering Contradiction:

Improvebonding uniformityVSAvoidbonding strength

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The patent resolves this contradiction by establishing an optimal viscosity range (10-15000 Pa·s) that balances bonding uniformity and strength, avoiding both excessive viscosity (causing unevenness) and insufficient viscosity (causing weak bonding)

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If the viscosity of the bonding layer is not controlled for easier assembly, then assembly ease is improved, but productivity decreases due to rework

Engineering Contradiction:

Improveassembly easeVSAvoidmanufacturing productivity

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent improves productivity by controlling the viscosity parameter within an optimal range that prevents bonding defects, thereby eliminating the need for rework and maintaining high assembly efficiency without compromising quality

Inventive Principle:

Principle #35Parameter changes

4Reliability

If the viscosity of the bonding layer is increased to reduce voids, then void formation is reduced, but bonding unevenness and misalignment increase

Engineering Contradiction:

Improvevoid preventionVSAvoidbonding alignment

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent resolves this contradiction by optimizing the viscosity parameter to a specific range that simultaneously prevents void formation and maintains bonding alignment, avoiding the harmful effects of excessive viscosity

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

This approach effectively suppresses bonding failures, unevenness, and misalignment, while ensuring proper sealing by maintaining the bonding layer's viscosity within optimal ranges, thereby enhancing the assembly process productivity and bonding strength.

Implementation Method 1

controlling the viscosity of the bonding layer within specific ranges for each process by adjusting the composition and heat treatment of the bonding material

Methodology Applied

Scientific EffectViscosity control:

Implementation Method 2

adjusting the composition and heat treatment of the bonding material

Methodology Applied

Scientific EffectHeat treatment: Heat Treatment

Implementation Method 3

using a noncontact applicator to apply a bonding layer on the semiconductor element's rear surface

Methodology Applied

Scientific EffectNoncontact application:

Data Source

PatentUS8629041B2Method for manufacturing semiconductor device

Publication Date: 2014.01.14 KIOXIA CORP

AI summary

According to one embodiment, a method is disclosed for manufacturing a semiconductor device. The method can include die bonding to bond a semiconductor element to a first position of a base member via a bonding layer provided on one surface of the semiconductor element. The method can include wire bonding to connect a terminal formed on the semiconductor element to a terminal formed on the base member by a bonding wire. In addition, the method can include sealing to seal the semiconductor element and the bonding wire. Viscosity of the bonding layer in the bonding is controlled not to exceed the viscosity of the bonding layer in the sealing.