Closed-Loop IR Camera Reflow Oven Temperature Control
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Solution Overview
Problem
Existing reflow ovens and wave solder machines lack precise temperature control over the printed circuit boards during the assembly process, leading to potential warpage and unreliable connections between electronic components and the circuit board.
Innovation Solution
A reflow oven and wave solder machine equipped with a closed-loop heat detection system using multiple infrared (IR) cameras strategically positioned to monitor temperatures of the circuit boards. This system provides real-time temperature data to a controller, enabling precise control of zone temperatures and conveyor speed to maintain optimal heating profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional temperature control systems are used in reflow ovens and wave solder machines, then the device complexity is reduced, but the manufacturing precision and reliability deteriorate due to temperature variance causing warpage and unreliable connections
Solution Approach 1:
The patent implements a closed-loop temperature control system using infrared cameras to continuously monitor the actual temperature of circuit boards in real-time. The measured temperature data is fed back to the controller, which automatically adjusts heating zone temperatures and conveyor speed to maintain the desired temperature profile, thereby achieving precise temperature control while managing system complexity through automated feedback mechanisms
Solution Approach 2:
The patent replaces traditional mechanical temperature measurement methods (such as contact thermocouples) with non-contact infrared thermal imaging technology. This substitution allows for continuous, real-time temperature monitoring without physical contact, eliminating measurement interference and simplifying the measurement system while improving temperature control precision
2Reliability
If multiple IR cameras and closed-loop control systems are added to monitor and control temperatures, then the manufacturing precision improves, but the device complexity and cost increase
Solution Approach 1:
The infrared camera system serves multiple functions simultaneously: it monitors temperature distribution across the entire circuit board, identifies hot spots and cold spots, validates temperature profiles, and provides feedback for real-time control adjustments. This multi-functionality justifies the added complexity by delivering comprehensive temperature management that improves connection reliability
Solution Approach 2:
The closed-loop control system automatically adjusts heating parameters and conveyor speed based on real-time temperature measurements without requiring manual intervention. The system self-regulates to maintain optimal temperature profiles, reducing the need for operator expertise and simplifying operation despite the complex underlying control mechanisms
3Measurement precision
If real-time temperature monitoring is implemented throughout the processing zones, then the manufacturing precision improves, but the loss of information is reduced and measurement precision increases
Solution Approach 1:
The patent transitions from point-based temperature measurement to area-based thermal imaging, capturing temperature data across the entire circuit board surface simultaneously. This dimensional change from 0D/1D measurement to 2D thermal mapping provides comprehensive temperature distribution information, improving measurement precision while the infrared technology itself manages the complexity of detecting multiple points at once
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 closed-loop temperature control system ensures consistent and reliable connections between electronic components and the circuit board, reduces warpage, and minimizes defects by maintaining precise temperature profiles throughout the assembly process.
Implementation Method 1
an infrared (IR) camera secured to the support bracket... The IR camera is configured to detect temperatures of the circuit board
Implementation Method 2
The reflow oven includes multiple heating zones... each heating zone having a heater assembly... configured to heat the circuit board
Implementation Method 3
a conveyor configured to transport circuit boards in the tunnel through the multiple processing zones
Implementation Method 4
The reflow oven includes a cooling zone... configured to cool the circuit board
Data Source
AI summary
An apparatus configured to join electronic components to an electronic substrate includes a chamber housing including a tunnel extending through multiple processing zones, a conveyor configured to transport electronic substrates in the tunnel through the multiple processing zones, and a heat detection system including at least one temperature sensor coupled to the chamber housing. The at least one temperature sensor is configured to detect temperatures of the electronic substrates passing proximate to the at least one temperature sensor. The apparatus further includes a controller coupled to the multiple processing zones, the conveyor and the heat detection system. The controller is configured to receive temperature data from the heat detection system.