Resistance Soldering Voltage Detection for Solder Element Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In resistance soldering methods for producing electrical machine windings, accurate positioning of the solder element between copper plates is critical, but existing automatic detection methods are complex and costly, leading to defective soldering points and increased rejection rates.

Innovation Solution

A control unit in the resistance soldering method determines the voltage between the solder element and specific points in the electric circuit, allowing for the detection of correct or incorrect positioning by comparing measured voltages with predefined values, thereby ensuring accurate alignment and preventing defective soldering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical detection by CCD camera is used to detect solder element position, then detection accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvesolder element position detection accuracyVSAvoidevaluation complexity and cost
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the optical detection system (CCD camera) with an electrical resistance-based detection system. By measuring the resistance value of the solder element through electrical contacts, the position detection is achieved through electrical means rather than optical means, thereby simplifying the device structure and reducing cost while maintaining detection accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electrical resistance as an intermediary parameter to detect the position of the solder element. Instead of directly observing the solder element's position optically, the system uses the electrical resistance property of the solder element (which varies with position) as a mediator to infer position information, simplifying the detection mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If automatic soldering is used to improve productivity, then production speed increases, but defective soldering points increase due to incorrect positioning

Engineering Contradiction:
Improveproduction speedVSAvoidsoldering quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the electrical resistance of the solder element is measured before and during the soldering process. Based on the resistance value changes, the system can determine whether the solder element is correctly positioned, providing feedback to control the soldering process and prevent defective soldering points, thus maintaining high reliability while achieving automatic high-speed production.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary detection of the solder element's position by measuring its electrical resistance before the soldering operation begins. This preliminary action ensures correct positioning is verified in advance, preventing defective soldering points from occurring during automatic high-speed production.

Inventive Principle:
Principle #10Preliminary action

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 approach simplifies and secures the detection of the solder element's position, reducing defective soldering points and component rejections by using the electrical resistance properties of the elements and electrodes to determine correct alignment.

Implementation Method 1

the control unit, upon the detection of the correct or incorrect position of the solder element in the plate assembly, determines at least one voltage which is constituted between the solder element and one point on the electric circuit

Methodology Applied
Scientific EffectVoltage measurement: Ohm's Law

Implementation Method 2

A voltage is applied to the electrodes of the soldering device, which then flows through the two copper plates and the solder element. As a result of the heat generated by the application of the voltage to the solder element, the latter melts and connects the two copper plates

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

the copper plates, together with the solder element, are compressed between the electrodes of the soldering device

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3725445B1Resistance soldering method and soldering device
Publication Date: 2022.01.05 MAHLE INT GMBH
  • EP3725445B1 patent drawingFigure 1
  • EP3725445B1 patent drawingFigure 2~3
  • EP3725445B1 patent drawingFigure 4~5

AI summary

The invention relates to a resistance soldering method (2) for producing a plate assembly (4) comprised of at least two basic elements (5a, 5b) which are materially bonded by means of the resistance soldering method (2), using a soldering device (1). The basic elements (5a, 5b) are spaced and, with respect to a mounting direction (10), are arranged one above the other between electrodes (3a, 3b) of the soldering device (1). A solder element (6) is further arranged between the basic elements (5a, 5b) and, together with the basic elements (5a, 5b), is compressed by the electrodes (3a, 3b) in the mounting direction (10). An output voltage (U0) is applied to the electrodes (3a, 3b), as a result of which the two basic elements (5a, 5b) are soldered to one another by means of the solder element (6). The correct or incorrect position of the solder element (6) in the plate assembly (4) is detected by a control unit (9). According to the invention, the control unit (9) determines the output voltage (U0), a first voltage (U1) between the first electrode (3a) and the solder element (6), and a second voltage (U2) between the second electrode (3b) and the solder element (6). Depending upon the output voltage (U0), the first voltage (U1) and the second voltage (U2), the control unit (9) detects the correct or incorrect position of the solder element (6) in the plate assembly (4). The invention further relates to the soldering device (1) for executing the resistance soldering method (2).