Thermosetting Resin Dispensing for CSP Mounting Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electronic component mounting lines face issues with poor bonding due to the flow and deformation of reinforcing resin over time, which can lead to insufficient melting and wetting of solder paste, resulting in poor quality mounting of CSPs and other components on substrates.
Innovation Solution
An electronic component mounting line and method that integrates a substrate feeding machine, screen printing machine, first and second electronic component placement machines, and a reflow machine, where the second electronic component placement machine dispenses thermosetting resin onto reinforcement positions on the substrate before placing the second electronic component, ensuring contact and preventing resin flow issues during the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If reinforcing resin is dispensed on the printed circuit board in advance before placing the CSP, then the bonding strength is improved, but the resin flows and deforms over time causing poor bonding quality
Solution Approach 1:
The dispensing head dispenses the reinforcing resin immediately before the placing head places the CSP, eliminating the time gap that causes resin deformation. This preliminary action ensures the resin is in optimal condition for bonding when the component is placed.
Solution Approach 2:
The dispensing head and placing head are integrated into the same electronic component placement machine, allowing both operations to be performed in immediate sequence without transferring the substrate to another machine. This merging eliminates idle time and maintains resin stability.
2Strength
If reinforcing resin is dispensed in advance, then the reinforcement effect is achieved, but the resin contacts solder paste causing insufficient melting and wetting
Solution Approach 1:
The resin is dispensed at the precise moment before CSP placement, ensuring it is positioned correctly and does not have time to flow into the solder paste area. This timing prevents contamination of the solder paste while still providing reinforcement.
Solution Approach 2:
The reinforcing resin is dispensed only at specific reinforcement positions corresponding to the peripheral edge portion of the CSP, not across the entire substrate. This localized application prevents resin from contacting solder paste in other areas while maintaining reinforcement where needed.
3Strength
If the resin height is adjusted to contact the CSP inner substrate, then the reinforcement is effective, but the resin loses shape over time and becomes too low
Solution Approach 1:
The resin is dispensed with the correct height and shape immediately before CSP placement, eliminating the time-dependent deformation issue. The resin maintains its intended geometry throughout the placement process because there is no idle time for it to lose shape.
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 approach prevents poor bonding by ensuring the thermosetting resin maintains its shape and contacts the second electronic component correctly, enhancing the bonding process and maintaining the reinforcement effect, thus improving the quality of electronic component mounting on substrates.
Implementation Method 1
heating the substrate on which the first and second electronic components have been placed, to melt the solder paste and the solder bumps
Implementation Method 2
bonding the first and second electronic components to the substrate, by heating the substrate on which the first and second electronic components have been placed, to melt the solder paste and the solder bumps and to cure the thermosetting resin
Data Source
AI summary
Disclosed is an electronic component mounting line on which a substrate undergoes solder paste printing, electronic component placements, and then reflow, while being moved from upstream to downstream. The line includes: a substrate feeding machine; a printing machine for applying solder paste to a first placement area of the substrate; a first electronic component placement machine for placing a first electronic component on the first placement area; a second electronic component placement machine for dispensing a thermosetting resin onto a reinforcement position on a peripheral edge portion of a second placement area of the substrate, and for placing on the area the second electronic component having solder bumps; and a reflow machine for bonding the electronic components to the substrate, by heating and cooling the resultant. The second electronic component is placed after the resin is dispensed, such that a peripheral edge portion thereof comes in contact with the resin.