Collared Pillar Electrodes for Low-Temperature Sinter Connections

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Solution Overview

Problem

Existing electronic chip connection methods face challenges in achieving reliable and efficient connections, particularly when sintering is performed at low temperatures without pressure, leading to issues with adhesion and consistency of sintering paste attachment.

Innovation Solution

The introduction of connecting pillars with a trunk, intermediate portion, and collar structure, along with a finishing layer, enhances the adhesion of sintering paste by ensuring a larger volume of paste remains attached during assembly, facilitating reliable connections without the need for high pressure or elevated temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If sintering is performed at low temperature without pressure, then energy consumption is reduced and manufacturing simplicity is improved, but adhesion reliability and sintering paste attachment consistency deteriorate

Engineering Contradiction:
Improvesintering temperatureVSAvoidadhesion reliability
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The collar structure creates a localized region with different geometric properties (larger lateral dimensions) compared to the trunk. This local quality change at the collar position enhances paste attachment specifically at this location, compensating for the low temperature sintering conditions without requiring high energy input throughout the entire structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The collar extends the pillar structure in the lateral dimension, creating a flared shape with larger lateral dimensions than the trunk. This dimensional expansion provides increased surface area for paste attachment, improving adhesion reliability without increasing the vertical height or requiring high temperature sintering.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If sintering is performed at low temperature without pressure, then manufacturing complexity is reduced, but sintering paste volume retention deteriorates

Engineering Contradiction:
Improvemanufacturing process complexityVSAvoidsintering paste volume
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The collar creates a localized expansion in the pillar structure with larger lateral dimensions, specifically designed to retain paste. This local quality modification ensures that paste volume is maintained at the critical connection interface without requiring complex manufacturing processes or high energy input.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The collar structure is pre-formed on the pillar before the sintering process. This preliminary action of creating the expanded collar region ensures that when paste is applied, it is naturally retained in the collar area, preventing paste loss without requiring additional manufacturing steps or high temperature processing.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If pillar structure is simplified, then manufacturing ease is improved, but connection reliability deteriorates

Engineering Contradiction:
Improvepillar manufacturing easeVSAvoidconnection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

Rather than simplifying the entire pillar structure, the invention applies a localized quality enhancement through the collar. The collar provides the necessary structural complexity only where needed (at the paste attachment region with larger lateral dimensions), while the rest of the pillar remains simple for easy manufacturing.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The pillar is segmented into distinct functional regions: the trunk for structural support and the collar for paste retention. This segmentation allows each part to be optimized independently - the trunk for manufacturing simplicity and the collar for connection reliability, achieving both goals simultaneously.

Inventive Principle:
Principle #1Segmentation

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

The described pillar structure ensures consistent and robust electrical connections by maintaining a sufficient thickness of sintering paste, enabling reliable adhesion and sintering at low temperatures, thereby improving the assembly process efficiency and reliability.

Implementation Method 1

heating to obtain sintering of the blocks of sintering paste

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP4521449B1Method of manufacturing an electronic chip comprising pillar electrodes for sinter connection
Publication Date: 2025.11.05 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4521449B1 patent drawingFigure 1~2
  • EP4521449B1 patent drawingFigure 3~5
  • EP4521449B1 patent drawingFigure 6~8

AI summary

This description relates to an electronic chip (10) comprising a support (12) and connecting pillars (15), each connecting pillar (15) comprising a trunk (16) having an end portion (30) and an intermediate portion (20) connecting the end portion (30) to the support (12) and comprising a collar (17) at the junction between the end portion (30) and the intermediate portion (20).