Reflow Soldering Oven Layout for Void Removal and Chamber Cleanliness

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Solution Overview

Problem

Existing reflow soldering ovens struggle to consistently prevent void formation in solder joints during the manufacturing of electronic circuit boards, leading to mechanical weakness, electrical resistance, and reliability issues, especially in high-power electronics, and vacuum chambers are prone to contamination that affects their performance.

Innovation Solution

A reflow soldering oven equipped with a vacuum system and a gas purification system, comprising upstream and downstream gas purification units, to remove voids and purify gases, minimizing contamination and ensuring a clean reflow process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a vacuum system is used to remove voids in solder, then void formation is minimized, but contamination occurs inside the vacuum chamber affecting performance

Engineering Contradiction:
Improvevoid formation in solderVSAvoidcontamination in vacuum chamber
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The harmful flux vapors and contaminants are extracted from the gas stream before it enters the vacuum chamber. The gas purification system removes these contaminants through filtration and chemical absorption, preventing them from accumulating in the vacuum chamber while maintaining the vacuum environment needed for void removal.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A gas purification system acts as an intermediary between the heating zone and the vacuum chamber. This intermediary system cleans the atmosphere before it enters the vacuum environment, allowing the vacuum system to function effectively without contamination from flux vapors and other harmful substances.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If traditional reflow soldering is used, then the process is simple, but voids form in solder joints causing reliability issues

Engineering Contradiction:
Improvereflow soldering processVSAvoidsolder joint reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The vacuum system and gas purification system are merged with the traditional reflow soldering process. The vacuum chamber is integrated into the soldering line, and the gas purification system is positioned to treat exhaust gases, creating a combined system that maintains simplicity while eliminating voids through reduced pressure during critical soldering phases.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If vacuum pump is operated continuously, then voids are removed effectively, but the pump malfunctions due to contamination

Engineering Contradiction:
Improvevoid removal efficiencyVSAvoidvacuum pump reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The gas purification system performs preliminary action by cleaning the exhaust gases before they reach the vacuum pump. Filters and chemical absorbers remove contaminants in advance, preventing accumulation of harmful substances that would otherwise cause pump malfunction and reduce its operational reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The gas purification system serves as a protective intermediary between the vacuum chamber environment and the vacuum pump. It prevents direct contact between contaminated gases and the pump internals, extending pump life and maintaining reliable operation during continuous void removal processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 combination of a vacuum system and gas purification system effectively minimizes or eliminates voids in solder joints, ensuring high-quality electronic circuit boards suitable for high-power electronics and reduces the risk of vacuum pump malfunction.

Implementation Method 1

a vacuum system comprising a vacuum pump and a vacuum chamber for removing voids on the electronic circuit board

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

a gas purification system for purifying gas that contains flux components vaporized from the electronic circuit board

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

a first temperature control chamber for applying a first temperature profile to the electronic circuit board; a second temperature control chamber for applying a second temperature profile to the electronic circuit board

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP4681851A1Improved reflow soldering oven
Publication Date: 2026.01.21 ILLINOIS TOOL WORKS INC
  • EP4681851A1 patent drawingFigure 1~2A
  • EP4681851A1 patent drawingFigure 2B
  • EP4681851A1 patent drawing

AI summary

A reflow soldering oven for soldering an electronic circuit board, the reflow soldering oven comprising: a first temperature control chamber for applying a first temperature profile to the electronic circuit board; a second temperature control chamber for applying a second temperature profile to the electronic circuit board; a vacuum system comprising a vacuum pump and a vacuum chamber for removing voids in a solder on the electronic circuit board, wherein the vacuum chamber is positioned intermediate the first temperature control chamber and the second temperature control chamber and is fluidly connected to the vacuum pump; and a gas purification system for purifying gas that contains flux components vaporized from the electronic circuit board.