WG Tech can fabricate vias in glass to facilitate microLED production. A pure laser via process cracks the glass, so they use a laser to make a pit, then etch the via. This capability is especially important for seamless tiling of glass-baIn his report for Insight Media at Display Week 2024, Chris Chinnock highlighted WG Tech, a company addressing a major bottleneck in microLED manufacturing: the inability to create vias (interconnects) in glass substrates.
Solving the Substrate Dilemma
- PCB Limitations: Currently, complex metalizations and vias are mostly done on PCBs, but these are limited to a pixel pitch of about 0.5 mm.
- The Glass Advantage: To achieve finer pitches, manufacturers must move to glass. However, until now, glass lacked the via technology necessary for back-side routing.
- TGV Technology: WG Tech demonstrated a Through Glass Via (TGV) process that uses a laser to create a “pit” followed by etching to avoid cracking the glass.
Technical Milestones
- Via Precision: They showcased a 150-micron thick glass sheet with 250-micron vias, though they can manufacture them as small as 10 microns.
- Ultra-Thin Development: The company is working on a project to create vias in glass as thin as 50 microns.
- Improved Yields: Unlike PCBs, glass is exceptionally flat, which significantly improves the yield and reliability of the bonding process during mass production.
Future Applications
Market Expansion: These glass-based substrates are being targeted for everything from high-end TV backlights to smartphones and wearables.
Tiling and Packaging: This technology enables seamless tiling for massive displays and the creation of Micro LED in Package (MiP) on glass, which was previously restricted to PCB.
