Semiconductor Package Mounting with Reinforcing Adhesive Segmentation

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Solution Overview

Problem

The existing semiconductor package component mounting process with a single heating step faces challenges in maintaining consistent quality due to difficulties in adjusting the quantity and position of thermoset resin, leading to variations in mechanical bonding strength and soldering quality.

Innovation Solution

Applying reinforcing adhesives before and after mounting the semiconductor package component, ensuring they are cured after the joining metal melts, reduces heating steps and prevents adhesive contact with melting solder, thereby stabilizing electrical joining and enhancing mechanical bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If thermoset resin is applied before mounting the semiconductor package component, then mechanical bonding strength is enhanced, but the resin may contact and mix with melting solder, degrading electrical joining quality

Engineering Contradiction:
Improvemechanical bonding strengthVSAvoidelectrical joining quality
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent segments the thermoset resin application into two distinct stages: pre-application at the substrate position and post-application at the component underside. This segmentation allows each application to serve a specific function without interfering with the soldering process, resolving the contradiction between mechanical bonding and electrical joining quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies thermoset resin to the substrate position before mounting the semiconductor package component. This preliminary action ensures the resin is in place to provide mechanical bonding support during the reflow process, while the component is mounted subsequently to avoid direct contact between the resin and melting solder.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If application quantity of thermoset resin is reduced to prevent contact with solder, then electrical joining quality is maintained, but mechanical bonding strength decreases

Engineering Contradiction:
Improveelectrical joining qualityVSAvoidmechanical bonding strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent divides the thermoset resin application into two separate applications: a first application to the substrate position and a second application to the component underside. This segmentation allows the total resin quantity to be distributed effectively, ensuring adequate mechanical bonding strength while preventing excessive resin from contacting the solder.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies thermoset resin to specific local positions: the substrate position and the component underside. This localized application ensures resin is placed precisely where mechanical bonding is needed, rather than applying large quantities that could contact the solder and degrade electrical joining quality.

Inventive Principle:
Principle #3Local quality

3Reliability

If two heating steps are used (reflow and curing), then electrical joining and mechanical bonding are both achieved, but process complexity and time increase

Engineering Contradiction:
Improveelectrical joining and mechanical bondingVSAvoidnumber of heating steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the reflow heating and curing heating into a single integrated heating process. The thermoset resin is formulated to cure at temperatures achievable during the reflow process, allowing both the solder to melt and the resin to cure in one heating cycle, thereby reducing process complexity and time.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration allows for stable electrical joining and sufficient mechanical bonding strength by reducing heating steps and preventing adhesive degradation, ensuring consistent quality even with reduced adhesive application.

Implementation Method 1

In the reflow, the solder of the bump electrodes 4 melts and the semiconductor package component 3 moves to a proper position by the self-alignment effect

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

the reinforcing adhesive is sufficiently cured after the joining metal melts

Methodology Applied
Scientific EffectCuring: Phase Change

Data Source

PatentEP2423955B8Method for mounting semiconductor package component, and structure having semiconductor package component mounted therein
Publication Date: 2019.10.09 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A semiconductor package component (3) is mounted on a substrate (1) in such a manner that an electrode (2) of the substrate (1) and an electrode of the semiconductor package component (3) are brought into contact with each other through a joining material (4). A reinforcing adhesive (5c) is applied between the substrate (1) and the outer surface of the semiconductor package component (3). Then, reflow is performed to melt the joining metal (4) with the reinforcing adhesive (5c) uncured. After the reinforcing adhesive (5c) is cured, the joining metal (4) is solidified.