LED Chip Die Bonding with Adhesive Droplet Arrays to Reduce Voids
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Solution Overview
Problem
Large-sized LED chips (≥20 mil) face issues of chip damage, failure, and poor conductivity due to voids in the conductive adhesive during the die bonding process, leading to stress and inadequate heat dissipation.
Innovation Solution
A method for die bonding an LED chip involves dispensing conductive adhesive multiple times based on the chip size, forming a preset adhesive droplet array with controlled distances and patterns to minimize voids and ensure even distribution, using a die bonding machine to place the chip on the bonding portion and cure the adhesive.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a large-sized LED chip (≥20 mil) is used to increase brightness, then the brightness of the LED device is improved, but chip damage, failure, and poor conductivity are more prone to occur
Solution Approach 1:
The conductive adhesive is divided into multiple droplets arranged in an array pattern instead of being applied as a single continuous layer. This segmentation allows for better distribution across the chip-substrate interface, reducing void formation and improving heat dissipation while maintaining reliable electrical connection for large-sized chips
Solution Approach 2:
The method pre-calculates and pre-arranges the adhesive droplet array based on the chip area before dispensing. The droplet positions, spacing, and quantities are determined in advance to optimize coverage and minimize voids, preventing chip damage and failure before they occur
2Ease of manufacture
If conventional single-time adhesive dispensing is used, then the process is simple, but voids form in the conductive adhesive leading to poor conductivity and heat dissipation
Solution Approach 1:
The adhesive application process is segmented into multiple dispensing actions, each creating a pattern of discrete droplets. This segmented approach ensures uniform distribution across the bonding area and eliminates the voids that form with single-time dispensing, improving conductivity without significantly complicating the manufacturing process
Solution Approach 2:
The conductive adhesive is dispensed in periodic intervals according to a pre-calculated array pattern. Multiple dispensing cycles create evenly spaced droplets that ensure complete coverage and eliminate voids, achieving precise adhesive distribution through rhythmic, controlled action
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
Reduces voids between the LED chip and substrate, lowering the risk of chip loss, failure, and improving conductivity by ensuring even adhesive distribution and effective heat dissipation.
Implementation Method 1
forming a preset adhesive droplet array corresponding to the one pad based on the area S of the LED chip to be placed and the radius R of an adhesive droplet formed by a dispensing device
Implementation Method 2
the radius R of an adhesive droplet formed by a dispensing device in a single dispensing action
Implementation Method 3
placing the LED chip on the bonding portion and curing the conductive adhesive
Data Source
AI summary
A method for die bonding an LED chip includes S1: forming a preset adhesive droplet array corresponding to one pad on a substrate based on the area S of one LED chip and the radius R of an adhesive droplet formed by a dispensing device in a single dispensing action, where parameters of the preset adhesive droplet array include the number X of adhesive droplets in a horizontal direction, the number Y of adhesive droplets in a vertical direction, and a horizontal distance H between two horizontally adjacent adhesive droplets, and a vertical distance D between two vertically adjacent adhesive droplets; S2: dispensing a conductive adhesive onto the pad multiple times according to the preset adhesive droplet array to form a bonding portion; and S3: placing the LED chip on the bonding portion and curing the conductive adhesive.