Laser Soldering Temperature Feedback for PCB Overheat Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The laser soldering process faces challenges with inconsistent energy accumulation due to varying component quality and oxidation levels, leading to potential damage from overheating or insufficient heating, and temperature feedback errors from abnormal light signals.
Innovation Solution
A laser soldering device and method that incorporate a power-adjustable laser source, temperature sensor, and feedback controller using a PID algorithm to maintain target temperatures, with a power meter for feedback and adjustable gains to manage laser power based on detected temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the output power of the laser beam is increased to ensure sufficient heating, then the heating temperature improves, but the soldering temperature becomes too high causing damage to components or PCB
Solution Approach 1:
The patent implements a temperature feedback mechanism where a temperature sensor detects the temperature of the soldering point and feeds this information back to a feedback controller. The feedback controller adjusts the laser output power based on the detected temperature, ensuring the temperature remains within the optimal range for soldering without causing damage to components or PCB.
Solution Approach 2:
The patent dynamically adjusts the laser output power during the soldering process based on real-time temperature feedback. The system transitions from a static power mode to a dynamic temperature feedback mode, allowing the laser power to vary continuously to maintain optimal soldering temperature.
2Object-affected harmful factors
If the laser output power is decreased to prevent overheating, then component damage is reduced, but the heating temperature becomes insufficient causing cold soldering or un-melted tin wire
Solution Approach 1:
The temperature feedback mechanism ensures that the laser power is adjusted in real-time based on actual temperature conditions. When the temperature is insufficient, the feedback controller increases the laser power; when the temperature is too high, it decreases the power, thus preventing both underheating and overheating.
Solution Approach 2:
The patent changes the laser output power parameter dynamically based on temperature feedback conditions. The system monitors temperature and adjusts the power parameter to maintain it within the optimal range, ensuring sufficient heating without causing damage.
3Reliability
If the temperature feedback mode is used to improve soldering quality, then the stability of soldering process improves, but soldering errors still occur when the laser beam excites abnormal light causing incorrect sensing signals
Solution Approach 1:
The patent introduces an intermediary optical filter between the laser beam and the temperature sensor to block abnormal light wavelengths. This filter allows only the relevant infrared wavelengths that correspond to the soldering point temperature to reach the sensor, preventing interference from abnormal laser light and ensuring accurate temperature measurement.
Solution Approach 2:
The patent converts the harmful effect of abnormal laser light excitation into a benefit by using the specific wavelength characteristics of the laser to selectively filter out interference. The optical filter is designed to transmit only the wavelengths emitted by the heated soldering point while blocking the laser's operating wavelength, thus transforming the interference problem into a selective measurement solution.
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 solution ensures precise temperature control, preventing overheating or underheating, and reduces soldering errors by dynamically adjusting laser power according to detected temperatures, enhancing the stability and quality of the soldering process.
Implementation Method 1
The temperature sensor receives infrared rays radiated when the laser beam is irradiated to the soldering point to detect the temperature of the soldering point
Implementation Method 2
The laser source emits a laser beam, which is power-adjustable, according to a control signal
Implementation Method 3
because the energy of the laser beam continues to accumulate, the soldering temperature can easily become too high
Data Source
AI summary
A laser soldering device includes a laser source, a lens group, a temperature sensor, and a feedback controller. The laser source emits a laser beam, which is power-adjustable, according to a control signal. The temperature sensor receives infrared rays radiated when the laser beam is irradiated to the soldering point to detect the temperature of the soldering point, and correspondingly outputs a sensing signal according to the detected temperature. When the detected temperature falls into a first temperature range based on a target temperature, the feedback controller executes a PID algorithm to calculate a predicted error value according to an error value between the detected temperature and the target temperature. The feedback controller controls the laser source according to the predicted error value, and adjusts the power of the laser beam accordingly, so that the detected temperature can be substantially equal to the target temperature.