Printed Etching Paste for Selective PCB Component Removal
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Solution Overview
Problem
Existing methods for removing electronic components from printed circuit boards often require high temperatures, chemical etching agents, or both, which can damage components and are energy-inefficient, and lack precision in selective removal.
Innovation Solution
A method and device for applying etching paste selectively to soldered joints on printed circuit boards using microdispensing or inkjet printing, followed by mechanical removal of the reaction product, allowing precise and controlled etching without high temperatures or immersion in chemicals, and enabling recovery of reusable components and materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high temperature heating is used to melt solder flux for component removal, then the solder flux melts and components can be removed, but energy consumption increases and electronic components may be damaged
Solution Approach 1:
The patent applies segmentation by dividing the PCB into individual component regions and selectively applying etching agent only to specific solder joints that need component removal, rather than heating the entire board. This localized approach reduces overall energy consumption while achieving the same component separation function.
Solution Approach 2:
The patent changes the fundamental parameter from thermal energy (heating) to chemical energy (etching agent). By using chemical etching at ambient or low temperatures instead of high-temperature heating, the process achieves solder joint dissolution with significantly reduced energy input while avoiding thermal damage to components.
2Temperature
If high temperature heating is used to melt solder flux for component removal, then the solder flux melts and components can be removed, but electronic components may be destroyed or their function affected
Solution Approach 1:
The patent fundamentally changes the parameter from thermal processing to chemical processing. By using etching agents at low temperatures instead of high-temperature heating, the process achieves solder joint removal while preserving the integrity and functionality of nearby electronic components that would be damaged by thermal exposure.
Solution Approach 2:
The patent applies local quality by selectively applying etching agent only to specific solder joints requiring component removal, while leaving other areas of the PCB and adjacent components unaffected. This localized chemical action ensures component integrity is maintained in regions not targeted for removal.
3Quantity of substance
If chemical etching agents are used to remove electronic components by immersing the entire PCB, then components are removed from the base plate, but other components, contacts and surfaces may be damaged
Solution Approach 1:
The patent applies segmentation by dividing the chemical treatment into localized applications at individual solder joints rather than immersing the entire PCB in chemical agent. This selective approach removes only targeted components while preserving other components and surfaces that do not require removal.
Solution Approach 2:
The patent applies local quality by using precise dispensing methods to apply etching agent only to specific solder joints where component removal is desired. This localized chemical action maintains the integrity of other components, contacts, and surfaces that remain unaffected by the etching process.
4Quantity of substance
If the entire PCB is immersed in chemical etching agent solution, then electronic components are transferred into the solution for removal, but excessive chemical agent is consumed and other components may be damaged
Solution Approach 1:
The patent applies segmentation by applying chemical etching agent in localized portions at individual solder joints rather than using a large volume to immerse the entire PCB. This dramatically reduces both chemical agent consumption and waste while achieving the same component removal function.
Solution Approach 2:
The patent applies partial action by using only the minimum necessary amount of etching agent required for each specific solder joint, rather than excessive immersion of the entire board. This optimized approach reduces chemical consumption and waste while maintaining effective component removal.
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
Enables energy-efficient, precise, and selective removal of electronic components from printed circuit boards, preserving undamaged components and recovering valuable materials like Sn, Pb, Ag, and Cu for reuse.
Implementation Method 1
an etching agent is applied to the soldered joint of an electronic component with a printed circuit board containing solder paste
Data Source
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AI summary
A method of selectively removing electronic components from printed circuit boards for subsequent recycling thereof, and device for carrying out the method according to the present invention, can be applied in recycling procedures whereby the electronic components are obtained from the printed circuit boards in this way, being, after inspection, sorted, and they can be offered on the aftermarket. The summary of the invention consists in that the etching agent is used as an etching paste 7 being applied to the printed circuit board 3 in a precise, local and selective manner by printing the etching paste print layer targeted to specific locations, i.e., to specific areas of soldered joints 5 of selected electronic components 2 which are arranged on the printed circuit board 3, thereby releasing the selected electronic component 2 from the printed circuit board 3.