Semiconductor Package Surface Roughening for Delamination Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

High-power semiconductor package assemblies are prone to delamination due to moisture ingress and ionic contamination, and existing methods for enhancing adhesion, such as roughening the lead frame, are costly and can cause solder wettability and pattern recognition issues.

Innovation Solution

A method involving a surface roughening treatment using an organic or inorganic chemical solution, like a photoresist layer stripping agent, is applied to the semiconductor package before encapsulation, improving adhesion with the molding resin while avoiding the negative effects of pre-existing surface roughening techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the lead frame surface is roughened to enhance adhesion with molding resin, then adhesion is improved, but solder wettability and pattern recognition are negatively impacted

Engineering Contradiction:

Improveadhesion between semiconductor package and molding resinVSAvoidsolder wettability and pattern recognition

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent applies selective surface roughening only to specific regions of the semiconductor package that require enhanced adhesion, while leaving other regions with smooth surfaces that are critical for soldering and pattern recognition. This localized approach allows different surface qualities in different areas to serve their specific functions optimally

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The surface roughening treatment is performed as a preliminary step before molding resin application, but with controlled parameters that prepare the surface for adhesion enhancement while preserving the underlying metal surface quality for subsequent soldering operations

Inventive Principle:

Principle #10Preliminary action

2Strength

If additional etching and finishing processes are applied to roughen the lead frame, then adhesion is improved, but manufacturing cost increases

Engineering Contradiction:

Improveadhesion between semiconductor package and molding resinVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent modifies the parameters of existing processes (such as etching time, chemical concentration, or mechanical treatment intensity) to achieve the required surface roughness for adhesion enhancement while minimizing additional process steps and cost increases

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent combines the surface roughening function with existing manufacturing processes, such as integrating it into the lead frame preparation step or combining multiple surface treatment functions into a single process, thereby reducing the need for separate additional processes

Inventive Principle:

Principle #5Merging (Combining)

3Strength

If the semiconductor package is subjected to surface roughening treatment, then adhesion with molding resin is improved, but the process complexity increases

Engineering Contradiction:

Improveadhesion between semiconductor package and molding resinVSAvoidprocess complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical surface roughening processes with simpler chemical treatment methods, or vice versa, using a treatment approach that achieves the desired surface morphology with fewer process parameters and simpler equipment requirements

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a surface treatment method that serves multiple functions simultaneously - enhancing adhesion, cleaning the surface, and preparing for subsequent processes - thereby reducing the need for multiple separate treatment steps

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Significantly reduces the risk of delamination and improves adhesion between the semiconductor package and the molding resin, while mitigating issues related to solder wettability and pattern recognition.

Implementation Method 1

the chemical solution is an organic or inorganic cleaning agent, for example a photoresist layer stripping agent

Methodology Applied

Scientific EffectChemical etching: Erosion

Data Source

PatentUS20230411175A1Method for manufacturing a semiconductor package assembly as well as such semiconductor package assembly

Publication Date: 2023.12.21 NEXPERIA BV

AI summary

A method for manufacturing a semiconductor package assembly is provided. The assembly includes a semiconductor package and a molding resin case encapsulating the semiconductor package. The complete semiconductor package undergoes a surface roughening treatment, thus improving the overall adhesion with the molding resin (EMC) and reducing the risks of delamination.