Solder Paste Lubrication for Jetting Clogging
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Solution Overview
Problem
Existing solder paste application methods, such as jetting and dispensing, face issues with clogging and agglomeration due to friction between solder balls and the surfaces of application components, leading to reduced efficiency and reliability, especially as components and nozzles are scaled down.
Innovation Solution
Incorporating 0.01% to 5% by volume of lubricating compounds like hexagonal boron nitride powder, fluorinated polymers, or soap-like structured molecules into the solder paste to reduce friction between particles and between particles and the application apparatus surfaces, thereby preventing agglomeration and clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If jetting or dispensing techniques are used to apply solder paste, then application speed and flexibility are improved, but friction between solder balls and application surfaces causes agglomeration and clogging
Solution Approach 1:
The patent introduces a lubricating agent as an intermediary substance between the solder balls and the application surfaces (nozzle, cylinder, piston). This lubricant reduces direct friction and prevents solder balls from sticking to surfaces, thereby resolving the contradiction between high-speed jetting/dispensing and clogging resistance. The lubricating agent enables smooth flow through narrow passages without compromising application speed or reliability.
Solution Approach 2:
The patent modifies the physical-chemical parameters of the solder paste by adding lubricating agents with specific properties (low friction coefficient, appropriate viscosity). This changes the flow characteristics of the paste, reducing internal friction between solder balls and external friction with application surfaces,ไป่ enabling reliable high-speed application without clogging.
2Productivity
If high pressure impulses are used in jetting to increase application speed, then productivity is improved, but violent treatment causes increased friction and agglomeration
Solution Approach 1:
The lubricating agent acts as a cushioning layer that is already present in the solder paste before jetting begins. When high pressure impulses are applied during jetting, the lubricant absorbs and distributes the mechanical stress, preventing direct violent contact between solder balls and application surfaces. This beforehand cushioning prevents agglomeration while allowing high-speed jetting operation.
3Loss of substance
If solid content of solder paste is increased to reduce material waste, then loss of substance is reduced, but viscosity increases causing flow problems and clogging
Solution Approach 1:
The patent changes the rheological parameters of the solder paste by incorporating lubricating agents. This allows the paste to maintain high solid content (reducing material waste) while the lubricant reduces effective viscosity and improves flowability. The lubricant creates a fluid dynamic environment that enables easy flow despite high solid loading, resolving the contradiction between material efficiency and operability.
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 addition of lubricating agents improves the flow and reduces wear, leading to more predictable behavior and longer lifespan of application devices, while ensuring strong and conductive solder joints are formed.
Implementation Method 1
The flux has a number of functions: making the paste behave as a (thick) liquid, be tacky enough to hold components before and during soldering, protecting the solder balls from oxidation, and removing the oxide from the solder balls and other surfaces during soldering.
Implementation Method 2
Incorporating 0.01% to 5% by volume of lubricating compounds like hexagonal boron nitride powder, fluorinated polymers, or soap-like structured molecules into the solder paste to reduce friction between particles and between particles and the application apparatus surfaces
Implementation Method 3
The needle is replaced by a narrow hole, the nozzle 2023, and the slowly varying pressure 2015 on the plunger 2012 is replaced by high pressure impulses symbolized by hammer blows 2025 and in real life implemented by a piezoelectric, magnetostrictive, thermal, etc. element.
Implementation Method 4
The paste contains 40-60% by volume of solder balls, typically 20 microns in diameter, and the rest of the volume is solder flux. The flux has a number of functions: making the paste behave as a (thick) liquid
Implementation Method 5
protecting the solder balls from oxidation, and removing the oxide from the solder balls and other surfaces during soldering
Implementation Method 6
There may be an activating compound for removing the oxide and making the solder wet the metal during soldering, often an organic acid and/or a halide-containing compound.
Data Source
AI summary
Solder paste compositions and methods for applying solder paste. The solder paste includes lubricating additives to the flux to decrease friction and the changes of metal to metal contact between the surfaces of the solder balls and other surfaces that the solder balls come into contact with. The solder paste also includes solder balls of different average sizes, that improves the desirable liquid like properties of the granular paste while further reducing viscosity. As such, the solder paste is used in current screen printing solder paste application methods without the risk of clogging or agglomeration of solder paste particles on surfaces. The solder paste is also used in jetting or dispensing solder paste application methods without the risk of clogging or agglomeration within the cylinders/containers or apertures and nozzles that are used within such methods.