PrintIn the pursuit of advancing next-gen tech, top engineers at OEMs are constantly pushing the boundaries of what’s possible in micro optics or optical molding. Through the design process however, some challenges can arise, catching even the most talented engineer off guard. By anticipating those challenges however, you can stay on schedule and on budget.
Specifically, in this piece I’ll cover miniaturization challenges, overcoming tight tolerances in design, navigating complex micro structures, overloading and sub-assemblies for optics, liquid silicone rubber challenges, and handling the parts themselves—which can be tricky.
Miniaturization and Micro Molding
From the mid to late 1990s, the field has evolved dramatically, driven by the demand for smaller, more complex optical components with added value like optical coatings and opto-mechanical sub-assemblies.
Why are engineers so focused on miniaturization of components and micro-molded optics? The trend spans multiple industries and applications. From the space race in the 60s to today’s cutting-edge technologies, engineering smaller and faster hardware has enabled incredible achievements. This drive is evident in everything from medical devices to consumer electronics and DataCom. In medical diagnostics, smaller optics are crucial for endoscopes and other diagnostic tools.
Generally, our DfMM has noticed the wide bulk of challenges OEM engineers face when working on their next micro optics or micro silicone optics project. Designing for tight tolerances, designing complex optical structures, LSR optics concerns, over-molding sub-assemblies, and the one often overlooked, handling micro parts.
Engineering Micro Optics Molding for Tight Tolerances
One major challenge when developing new micro optics parts is maintaining tight tolerances. As devices become smaller, the precision required increases significantly.
Engineers often push suppliers to innovate and find ways to achieve these stringent tolerances—and those suppliers often agree at first. But achieving micro tolerances is far more difficult. Our engineers have micro molded optics under 1mm in diameter and maintaining complex part geometry that fit to 0.125mm fiber. This demonstrates the industry’s need to meet more strict demands by the day. Similarly, molding lenslets within larger structures—such as five lenslets with a base radius of 37µm within a 0.25mm diameter.
Complex Micro Optics Structures
Beyond size and handling, the complexity of optical structures is another challenge that can befuddle the most die-hard engineering team. Modern applications require parts with integrated optical surfaces and freeform shapes, such as components featuring multiple off-axis anamorphic aspheres. This complexity necessitates advanced manufacturing techniques and innovative solutions from engineers.
Overmolding and sub-assemblies for optics
The ability to overmold and create sub-assemblies is a critical resource for OEM engineering teams as well. For instance, overmolding a glass mirror into a housing and subsequently adding three separate plastic optics, sending them out for AR coating, and integrating them into a final assembly is complicated. This process requires precise coordination with a micro molder and custom-designed automation capabilities to account for part placement.
Liquid Silicone Rubber (LSR) challenges
Liquid Silicone Rubber (LSR) optics introduce additional challenges and opportunities in micro molding projects. LSR can flow into very complex shapes without secondary operations to remove flash, a common industry issue. It can also be overmolded into a sub-structure, offering clarity in the visible light range, extreme temperature tolerance, excellent biocompatibility, and high chemical resistance.
Handling Micro Molded Parts
Another significant challenge is handling these tiny micro molded optics, and silicone optics parts. Creating the component is complicated, but handling it, packaging it, and preparing to accommodate later assembly can be an unexpected challenge.
Engineers frequently turn to more sophisticated automation systems to manage the delicate and precise nature of micro-molded optics. Automation not only ensures accuracy but also supports high-volume production, essential for meeting market demands efficiently.
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For engineers at OEMs working on next-generation technology, the challenges of micro-molded optics are significant but success is achievable. As our team meets the need for tighter tolerances, advanced part handling, complex optical structures, and innovative materials, world-class engineers can continue to push the boundaries of what’s possible.