Sven Hujo | DELO Industrial Adhesives: What if your adhesive could not only secure your microLEDs but also boost their light output?
00:05:44 - 00:07:03
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Summary of the clip:
What if your adhesive could not only secure your microLEDs but also boost their light output?
Even when using traditional solder reflow, challenges like void formation under the die can compromise thermal and mechanical performance. A capillary underfill, a low-viscosity adhesive dispensed next to the chip, wicks underneath via capillary action to fill these voids. This process secures the die, prevents movement during subsequent reflow steps, and significantly reinforces the fragile solder joints against mechanical stress.
The mechanical reinforcement provided by an underfill dramatically improves the overall reliability of the assembly, especially for components with gap sizes below 50 micrometers. It increases the die shear strength and protects the component from stresses induced by thermal cycling and mechanical shock or vibration. This is particularly crucial for devices with small components and fine-pitch interconnects, where the solder joints themselves are inherently weak.
Underfills can be engineered for more than just mechanical support. By incorporating white, reflective fillers into the adhesive formulation, the underfill can act as a micro-reflector around the base of the LED chip. This white underfill scatters and reflects light that would otherwise be absorbed or trapped by the substrate, effectively increasing the total light output and improving the overall efficiency of the display package.
In this short video, you can learn:
* How capillary underfills eliminate voids and reinforce solder joints in micro-assembly.
* The role of underfills in improving die shear strength and overall device reliability.
* The novel use of white, reflective underfills to increase the light output of LED packages.
š **Clip Abstract** This clip explains the function and benefits of capillary underfills in advanced electronic packaging. It details how these materials reinforce solder joints to improve mechanical reliability and can even be formulated with white fillers to enhance the light output of LED components.
š Link in comments š
#CapillaryUnderfill, #MicroLEDs, #SolderJointReliability, #ReflectiveUnderfill, #ARdisplays, #AdvancedPackaging
This is a highlight of the presentation:
Investigation of Electrically Conductive Adhesives for Miniaturized SMD Components
More Highlights from the same talk.
00:00:29 - 00:02:00
Is solder obsolete for microLED assembly? Anisotropic Conductive Adhesives (ACAs) offer a compelling alternative that eliminates the risk of short circuits.
Is solder obsolete for microLED assembly? Anisotropic Conductive Adhesives (ACAs) offer a compelling alternative that eliminates the risk of short circuits.
Non-Conductive Adhesives (NCAs) are simple structural glues, but for electrical connection, they require pre-formed interconnects like stud bumps to penetrate the adhesive and make contact. This adds complexity to the component or substrate, requiring an extra processing step to create the physical bumps that will establish the electrical pathway through the insulating adhesive layer.
Isotropic Conductive Adhesives (ICAs) are conductive in all directions, much like solder paste. This creates a significant process challenge for fine-pitch components like microLEDs, as precise dispensing is required to avoid the adhesive spreading and bridging between adjacent contact pads, which would cause a short circuit. This need for high-precision deposition can slow down production and reduce yield.
Anisotropic Conductive Adhesives (ACAs) are the game-changer for high-density interconnects. They contain conductive particles but are only conductive in the Z-axis (vertically) when compressed between the chip and the substrate. This means you can apply the adhesive over an entire area without worrying about lateral (X-Y) conductivity, completely eliminating the risk of short circuits and dramatically simplifying the assembly process for mini and microLEDs.
In this short video, you can learn:
* The fundamental differences between NCA, ICA, and ACA bonding technologies.
* Why traditional isotropic conductive materials pose a short-circuit risk for fine-pitch components.
* How Z-axis-only conductivity in ACAs simplifies microLED assembly and enhances process reliability.
š **Clip Abstract** This clip explains the three main types of adhesives used for electronic component assembly: Non-Conductive (NCA), Isotropic Conductive (ICA), and Anisotropic Conductive (ACA). It highlights why ACAs are particularly advantageous for high-density applications like mini and microLED displays, as their unique Z-axis conductivity prevents short circuits.
š Link in comments š
#AnisotropicConductiveAdhesives, #IsotropicConductiveAdhesives, #NonConductiveAdhesives, #MicroLEDAssembly, #MicroLEDDisplays, #ARdisplays
00:03:39 - 00:05:28
Can adhesives really match the electrical performance and reliability of solder for demanding display applications? The data might surprise you.
Can adhesives really match the electrical performance and reliability of solder for demanding display applications? The data might surprise you.
Electrical performance is a critical metric for any interconnect material. This clip presents I-V curve data for miniLEDs bonded with DELO's anisotropic conductive adhesive. The results show that the electrical characteristics are virtually identical to the manufacturer's datasheet specifications (which assume solder) and, crucially, remain stable with no significant change even after 500 hours of thermal aging at 120Ā°C.
Beyond electrical stability, mechanical robustness is essential for long-term device reliability. Die shear tests were performed to quantify the adhesion strength of the ACA, which is a measure of how much force is required to push the chip off the substrate. The results demonstrate high initial adhesion, reaching values up to 10 Megapascals, indicating a strong, reliable bond for such small components.
The true test of reliability comes from accelerated aging under harsh conditions. The clip shows that the high die shear strength is maintained with minimal degradation after both 500 hours at 120Ā°C and, even more impressively, after 500 hours of 85Ā°C / 85% relative humidity (damp heat) testing. This proves the material's resilience to both thermal and environmental stressors, making it suitable for robust, long-life products.
In this short video, you can learn:
* How the electrical performance (I-V curve) of ACA-bonded miniLEDs compares to solder.
* The mechanical strength (die shear) achievable with modern conductive adhesives.
* How these critical properties hold up after extensive thermal and damp heat (85/85) reliability testing.
š **Clip Abstract** This clip presents compelling reliability data for anisotropic conductive adhesives used in miniLED assembly. It demonstrates through I-V curves and die shear tests that the adhesive provides stable electrical performance and robust mechanical adhesion, even after prolonged thermal and damp heat aging.
š Link in comments š
#MiniLEDAssembly, #AnisotropicConductiveAdhesive, #DisplayReliability, #DieShearTesting, #MicroLEDDisplays, #ARVRDisplays