Zeolite Box Reflow Oven for Stable Gas Ratios and Sensor Protection

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Solution Overview

Problem

The quality of soldered products in reflow soldering is inconsistent due to unstable gas ratios in the reflow oven hearth, caused by incomplete removal of flux by the separator, leading to incorrect oxygen content readings and sensor failures, and adding a filter increases flow resistance.

Innovation Solution

A reflow oven design incorporating a zeolite box with a net cage and polygon-shaped zeolites to further remove residual flux, connected in series with the separator and sensor, allowing for controlled nitrogen input to maintain stable gas ratios, using a zeolite box with a chamber and inner net cage to facilitate zeolite replacement and minimize flow resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separator is used to remove flux from gases, then the gas can be recovered and reused, but the flux removal is incomplete and residual flux condenses at the sensor, causing incorrect readings or sensor failure

Engineering Contradiction:
Improvesensor reliabilityVSAvoidflux removal completeness
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent introduces a zeolite box as an intermediary component between the separator and the sensor. The zeolite box contains residual flux components that would otherwise reach and contaminate the sensor, while allowing the nitrogen gas to pass through to the sensor for accurate oxygen content detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses zeolite, a porous material with molecular sieve properties, to selectively adsorb residual flux components from the gas stream. The porous structure of zeolite allows it to trap harmful substances while permitting the passage of the carrier gas, thus protecting the sensor without blocking gas flow.

Inventive Principle:
Principle #31Porous materials

2Reliability

If a filter device is added to remove residual flux, then the sensor is protected, but the flow resistance of gases in the filtering passage increases

Engineering Contradiction:
Improvesensor protectionVSAvoidgas flow rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent employs zeolite, a porous material with controlled pore sizes, to create a filtering mechanism that does not significantly impede gas flow. The porous structure provides numerous pathways for gas to pass through while still capturing residual flux, thus maintaining productivity while protecting the sensor.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent applies the zeolite filtering function locally in the gas passage between the separator and sensor, rather than using a comprehensive filter throughout the entire system. This localized approach provides targeted protection where needed while minimizing overall flow resistance.

Inventive Principle:
Principle #3Local quality

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 zeolite box effectively removes residual flux, protecting the sensor and maintaining stable gas ratios by controlling nitrogen input, ensuring consistent soldering quality without increasing flow resistance.

Implementation Method 1

a zeolite box, said zeolite box comprising a zeolite box inlet and a zeolite box outlet, said zeolite box inlet being connected to said separator outlet

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3672754B1A reflow oven with a zeolite box, and a method of recovering gas with such zeolite box
Publication Date: 2021.10.06 ILLINOIS TOOL WORKS INC
  • EP3672754B1 patent drawingFigure 1
  • EP3672754B1 patent drawingFigure 2
  • EP3672754B1 patent drawingFigure 3

AI summary

The present application provides a reflow oven (100) and a gas recovery method. The reflow oven (100) comprises a reflow oven hearth (101), a separator (105), the separator inlet (110) being connected to the gas outlet (102) of the reflow oven hearth (101) so that the gases in the reflow oven hearth (101) can flow into the separator (105), a zeolite box (107), the zeolite box inlet (112) being connected to the separator outlet (111), and the zeolite box outlet (113) being connected to the gas inlet (103) of the reflow oven hearth (101) so that the gases flowing through the separator (105) can enter the zeolite box (107) and the gases flowing through the zeolite box (107) can flow out of the zeolite box outlet (113), a sensor (106), which is provided in the gas passage between said zeolite box outlet (113) and the gas inlet (103) of the reflow oven hearth (101). The reflow oven (100) in the present application enables the gases flowing through the separator (105) to enter the zeolite box (107). After most of the flux is removed from the gases in the separator (105), the flux is further removed in the zeolite box (107). In addition, polygonal zeolites have certain volumes and are supported in the zeolite box (107) to form clearances, and thus almost no resistance is brought about to the flow of the gases in the zeolite box (107).