Vacuum Solderability Testing System for MicroNewton Wetting Force Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solderability testing methods for small surface mount components face challenges in accurately measuring wetting forces due to inadequate sensitivity and non-uniform heating, particularly with smaller pin sizes and reduced solder amounts, leading to unreliable results from thermal currents and heating inconsistencies.
Innovation Solution
A system utilizing a vacuum chamber with a load sensor and precise control mechanisms to measure wetting forces over time, incorporating a load sensor with microNewton measurement accuracy and a heating element to maintain uniform temperature, allowing for accurate assessment of solderability by minimizing thermal currents and ensuring precise force measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If analytical balances with milliNewton measurement sensitivity are used for solderability testing, then the testing arrangement is simple and widely available, but the measurement precision is inadequate for measuring microNewton-level wetting forces of small pin components
Solution Approach 1:
The patent changes the measurement parameter from milliNewton to microNewton level by using a specialized load sensor capable of measuring forces in the order of microNewtons. This parameter change enables accurate measurement of wetting forces for small pin components while maintaining a relatively simple testing arrangement that builds upon conventional solderability testing methodology.
2Temperature
If components are suspended over molten solder for heating prior to immersion, then the component is heated before testing, but the heating is non-uniform which does not mimic real reflow oven conditions
Solution Approach 1:
The patent introduces a susceptor as an intermediary element between the heating source and the component. The susceptor is placed underneath the component and heated by induction, which then uniformly heats the component from below. This intermediary approach achieves uniform heating that mimics reflow oven conditions while maintaining operational simplicity through automated induction heating.
3Measurement precision
If testing is performed in air at standard pressure, then the testing environment is simple and accessible, but thermal currents are high enough to cause unreliable measurements of small wetting forces
Solution Approach 1:
The patent employs a vacuum chamber to create a vacuum environment during solderability testing. This eliminates air thermal currents that would otherwise interfere with accurate measurement of small wetting forces. The vacuum environment, while adding some complexity, ensures reliable and precise measurements by removing the harmful thermal current effect.
4Length of moving object
If smaller pin sizes and reduced solder amounts are used, then the component size is reduced for modern electronics, but the wetting forces become too small for accurate measurement with conventional equipment
Solution Approach 1:
The patent addresses the challenge of measuring extremely small wetting forces by changing the measurement sensitivity parameter to microNewton level. This enables accurate measurement of wetting forces for small pin components with reduced solder amounts, allowing the testing methodology to remain valid for modern miniaturized electronics.
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 system provides reliable and precise measurements of solderability, enabling accurate determination of surface tension and wetting forces for small components, reducing errors from thermal currents and ensuring uniform heating, thus improving the reliability of solderability testing.
Implementation Method 1
the load sensor measures force arising from wetting of the solder to the contact surface
Implementation Method 2
when measuring such small forces, thermal currents in air at standard pressure may be high enough relative to the small wetting forces that unreliable results would be recorded
Implementation Method 3
a heating element to maintain uniform temperature
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The described embodiments relate generally to methods and system for use in determining solderability of an electrical component. One particular aspect relates to a system for measuring solderability of an electrical component, comprising: a vacuum chamber; a load sensor having a contact portion, the contact portion being disposed within the vacuum chamber; a first receptacle for containing solder; a platform or support disposed within the vacuum chamber in relation to the contact portion and having a component mounting surface for mounting the electrical component; and a control and communications module for causing relative movement between the platform or support and the load sensor so that a contact surface of the electrical component is brought into close proximity with the contact portion. When the contact portion has solder thereon and the solder is brought into contact with the contact surface, the load sensor measures force arising from wetting of the solder to the contact surface; wherein the control and communications module is configured to monitor sensed conditions within the system. The force generated under contact changes over time, depending on the degree of solderability of the electrical component. Thus, measurement of the wetting forces over time provides an indication of the solderability of the electrical component.