Michael Cullinan | The University of Texas at Austin: What are the key challenges in scaling traditional selective laser sintering down to the microscale for bump fabrication?
00:03:09 - 00:03:34
Other snippets from this talk
Summary of the clip:
What are the key challenges in scaling traditional selective laser sintering down to the microscale for bump fabrication?
The speaker contrasts their approach with traditional selective laser sintering (SLS) and direct metal laser melting (DMLM) processes. SLS involves spreading a powder of metal particles, scanning a laser to locally melt the particles, and repeating the process layer by layer to build a 3D part. While effective for larger structures, scaling down to microscale bump fabrication presents significant challenges.
The limitations of traditional SLS at the microscale stem from several factors. Laser spot sizes are typically on the order of tens to hundreds of microns, and powder particle diameters range from 10 to 50 microns. Furthermore, the heat-affected zones around the laser-patterned spots are quite large, making it difficult to achieve the desired resolution and precision for microscale features.
These challenges necessitate a different approach that can overcome the limitations of traditional SLS. The speaker's team developed a microscale selective sintering process that addresses these issues by using nanoparticle inks and a digital micromirror array for precise patterning. This allows for the creation of sub-micron features with higher resolution and reduced heat-affected zones.
In this short video, you can learn:
* The basic principles of selective laser sintering (SLS).
* The limitations of SLS when applied to microscale fabrication.
* The challenges related to laser spot size, powder particle size, and heat-affected zones.
š **Clip Abstract:** This segment explains the limitations of traditional selective laser sintering (SLS) for microscale bump fabrication, focusing on challenges related to laser spot size, powder particle size, and heat-affected zones. It provides context for the speaker's alternative approach using nanoparticle inks and a digital micromirror array.
š Link in comments š
#SelectiveLaserSintering, #MicroscaleFabrication, #BumpFabrication, #HeatAffectedZones, #SemiconductorPackaging, #Microelectronics
This is a highlight of the presentation:
Selective micro scale sintering for next generation of bump fabrication
More Highlights from the same talk.
00:00:36 - 00:00:42
How can bump structures be fabricated without the need for creating new masks for each design iteration, especially at industrial resolutions?
How can bump structures be fabricated without the need for creating new masks for each design iteration, especially at industrial resolutions?
The speaker introduces the core problem they are addressing: the need to fabricate bump structures for chiplet integration without the costly and time-consuming process of creating new masks for each design change. Traditional methods involve static mask designs, patterning, material filling, and electroplating, requiring a new mask for every design alteration. This becomes a bottleneck for rapid prototyping and low-volume applications.
The goal is to achieve this maskless fabrication at industrial resolutions, specifically targeting sub-10 micron pillar diameters. This level of precision is crucial for meeting the demands of their customer applications in semiconductor packaging. The focus is on developing an additive manufacturing process that can scale to meet these requirements.
The speaker's team is focused on scaling bump fabrication using an additive process, moving from solder ball jetting (50-100 micron range) to below 10 microns. This is driven by the need for finer pitches in pillar arrays used in semiconductor packaging. The initial step involved evaluating existing automated packaging systems and their capabilities.
In this short video, you can learn:
* The limitations of traditional mask-based bump fabrication.
* The need for additive manufacturing solutions in chiplet integration.
* The target resolution and throughput for industrial applications.
š **Clip Abstract:** This segment highlights the limitations of traditional mask-based bump fabrication and introduces the need for a maskless, additive manufacturing approach to enable rapid prototyping and low-volume production of chiplets with sub-10 micron pillar diameters. It sets the stage for the speaker's microscale selective sintering process.
š Link in comments š
#MasklessFabrication, #BumpStructures, #AdditiveManufacturing, #Sub10MicronPillars, #ChipletIntegration, #SemiconductorPackaging
00:04:04 - 00:04:15
How does the use of nanoparticle inks, instead of powders, overcome the limitations of traditional selective laser sintering for microscale additive manufacturing?
How does the use of nanoparticle inks, instead of powders, overcome the limitations of traditional selective laser sintering for microscale additive manufacturing?
The speaker details the key differences between their microscale selective sintering process and traditional SLS, emphasizing the use of nanoparticle inks instead of macroscale particles. Their process utilizes inks containing sub-100 nanometer particles, which presents its own set of challenges, particularly in terms of spreading. Unlike powders, nanoparticles tend to stick together, necessitating the use of an ink-based delivery method.
The process involves spreading a layer of nanoparticle ink, drying the layer, and then performing the patterning step. This is repeated layer by layer to build the 3D structure. The use of nanoparticle inks allows for the creation of much thinner layers compared to powder-based methods, enabling higher resolution and finer feature sizes.
The speaker also highlights the incorporation of a digital micromirror array (DMD) to address the need for patterning small features at high throughput. The DMD allows for the simultaneous patterning of approximately 2 million one-micron spots, significantly increasing the speed and efficiency of the process compared to single-spot laser scanning. This combination of nanoparticle inks and DMD-based patterning is crucial for achieving the desired resolution and throughput for microscale bump fabrication.
In this short video, you can learn:
* The advantages of using nanoparticle inks in microscale selective sintering.
* The challenges associated with spreading nanoparticle inks.
* The role of a digital micromirror array (DMD) in high-throughput patterning.
š **Clip Abstract:** This segment explains how the use of nanoparticle inks and a digital micromirror array (DMD) in the speaker's microscale selective sintering process overcomes the limitations of traditional powder-based SLS, enabling higher resolution and throughput for microscale bump fabrication. It highlights the key differences in material delivery and patterning techniques.
š Link in comments š
#NanoparticleInks, #MicroscaleSLS, #DigitalMicromirrorArray, #MicroAdditiveManufacturing, #AdvancedPackaging, #SemiconductorManufacturing