Reflow Soldering Device Vacuum Control Gas Inclusions
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Solution Overview
Problem
Soldering processes face challenges in reliably heating large-area thermal connections and preventing gas inclusions, which lead to cavities in soldered joints, increasing thermal resistance and reducing the service life of semiconductor components, especially in power electronics where defects can cause thermal and electrical failures.
Innovation Solution
A reflow soldering device with a heat source and vacuum control system that applies negative pressure twice during the soldering process to remove gas inclusions, utilizing a vacuum control device to generate a vacuum at least twice when the solder is at or above the liquidus temperature, and an overpressure control device to compress remaining gas inclusions as the solder solidifies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If large-area thermal connections are used to dissipate power loss, then heat dissipation capability is improved, but gas inclusions and cavities form during soldering, increasing thermal resistance
Solution Approach 1:
The patent applies negative pressure during the soldering process to change the physical parameters of the solder material and gas inclusions. By reducing pressure, the boiling point of the solder is lowered and gas inclusions are removed from the liquid solder, preventing cavity formation while maintaining large-area thermal connections for heat dissipation
Solution Approach 2:
The patent employs periodic vacuum cycles during the soldering process - applying negative pressure at specific intervals when the solder is in liquid state, then releasing to atmospheric pressure. This periodic application of vacuum allows gas inclusions to be repeatedly removed while the solder solidifies, ensuring low thermal resistance in the final joint
2Reliability
If negative pressure is applied once during soldering, then some gas inclusions are removed, but remaining gas inclusions and outgassing still form cavities
Solution Approach 1:
The patent implements multiple periodic vacuum cycles during the soldering process. Each cycle applies negative pressure to remove gas inclusions, then releases to atmospheric pressure. This periodic repetition continues until the solder solidifies, ensuring that both initial gas inclusions and subsequent outgassing from plastics are removed, achieving comprehensive cavity reduction
Solution Approach 2:
The patent applies vacuum cycles at strategically timed moments during the soldering process - specifically when the solder is in liquid state but before complete solidification. This preliminary action removes gas inclusions at the most effective moment, and subsequent vacuum cycles address outgassing from plastics and potting compounds as they occur
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
Significantly reduces the volume of gas inclusions in soldered connections, minimizing thermal resistance and preventing defects, thereby enhancing the reliability and service life of semiconductor components by effectively managing gas inclusions and outgassing from plastics and potting compounds.
Implementation Method 1
at least one vacuum control device configured to generate a vacuum around the solder material at least twice during a time interval in which the solder material has a temperature that is greater than or equal to the liquidus temperature
Implementation Method 2
at least one heat source configured to heat a solder material at least up to a liquidus temperature
Data Source
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AI summary
The invention relates to a device for reflow soldering, which has at least one heat source, which is designed for heating up a solder material at least to a liquidus temperature, and which has at least one negative-pressure controlling device, which is designed for producing a negative pressure at least twice around the solder material during a time interval in which the solder material has a temperature that is greater than or equal to the liquidus temperature.