Calcium borosilicate (Ca2B2SiO7) candidate packaging dielectric — dielectric properties pending

Ca2B2SiO7 — calcium borosilicate with the stoichiometry two calcium, two boron, one silicon, seven oxygen — sits within the wide-band-gap borate dielectric platform as a backup arm, added specifically to broaden the genus coverage of the lead borate dielectric claims. Its strategic role is not to supplant the primary lead members but to extend the protective perimeter: by establishing phonon-proven dynamic stability for this composition now, the filing preserves priority and genus completeness for a supply-chain-clean borosilicate candidate, allowing the dielectric property corner to be validated experimentally or computationally afterward without losing the filing date. That structure — prove structural credibility first, close the property gate second — reflects a deliberate prosecution strategy. What makes this backup arm commercially meaningful is the supply-chain dimension. Unlike certain cadmium-containing members in the same backup tier, Ca2B2SiO7 is composed entirely of calcium, boron, silicon, and oxygen — none of which falls under major restriction-of-hazardous-substances frameworks. In a semiconductor packaging and power-device passivation market that faces mounting pressure to eliminate toxic heavy metals from dielectric stacks, a phonon-stable borosilicate with no supply-chain encumbrances has real optionality value even before its dielectric properties are pinned. The timing is deliberate: GaN and SiC power device shipments are scaling fast, OEMs are requalifying dielectric interlayers, and a clean, computationally credentialed borosilicate that closes the property gates promptly could move from backup arm to primary position if the lead members encounter prosecution headwinds or manufacturing obstacles. The honest investor framing is that Ca2B2SiO7 is not the headline asset in this portfolio. It is a well-positioned defensive and genus-completion filing that carries real value as optionality in the critical-mineral recovery and recycling separations portfolio, in the event that the lead members face design-around, sourcing constraints, or that the dielectric properties of calcium borosilicate prove superior once measured. The value of the backup arm is therefore asymmetric: low cost to maintain, meaningful upside if the property gates close favorably, and meaningful defensive value regardless.

Each candidate is validated by multiple independent machine-learning interatomic potentials. A material advances only when the engines agree on phonon (dynamic) stability — disagreement is surfaced, not hidden.

Ca2B2SiO7 belongs to the borate-silicate framework class — a mixed-anion oxide in which tetrahedral SiO4 units and boron-oxygen polyhedra (BO3 or BO4, depending on coordination) share corners to build a three-dimensional network, with calcium ions occupying interstitial sites. This structural family is chemically distinct from conventional alkali borosilicate glasses: the crystalline borate-silicate framework has well-defined long-range order, stoichiometrically fixed cation ratios, and phonon dispersions that can be computed and compared against independent potentials in a way that glass-network formers cannot. The crystalline form is what is claimed and what has been screened. The computational validation completed to date consists of a cross-machine-learning-interatomic-potential phonon stability screen. Two independent machine-learning potentials drawn from the Lattice Graph validation stack — trained on distinct datasets and architectures — were applied to the Ca2B2SiO7 structure, and both agree that the material is dynamically stable: no imaginary phonon modes appear anywhere in the Brillouin zone, and the minimum vibrational frequency is positive. This is a meaningful threshold. Imaginary modes at zone-center or zone-boundary indicate that the predicted equilibrium structure is actually a saddle point on the energy landscape — the material would spontaneously distort. The consensus of two independent potentials substantially reduces the probability that this stability verdict is an artifact of one potential's training-data distribution. A single-potential phonon calculation can spuriously predict stability for configurations outside its training manifold; requiring both potentials to agree provides an independent cross-check that mirrors the function of a second expert opinion. The underlying structural input is supported by one DFT reference source. What remains open — and this is stated with complete candor — is the dielectric property corner. No DFPT (density-functional perturbation theory) calculation of the static dielectric tensor has yet been performed for this composition, and no electronic band gap has been computed or measured. For a dielectric candidate in semiconductor packaging, both quantities are non-negotiable for prosecution and licensing: the static permittivity determines whether the material can outperform or match incumbent low-k or moderate-k interlayers, and the band gap determines leakage suppression and breakdown field headroom. Until the DFPT-eps calculation closes this gate, Ca2B2SiO7 cannot be asserted to have any specific permittivity or loss tangent advantage. The computational roadmap is clear — DFPT static dielectric tensor plus band gap — and the calcium-boron-silicon-oxygen chemistry is fully tractable with standard plane-wave DFT codes, so closing this gate is a defined, bounded task rather than an open-ended research question. For context on what the target property space looks like: the wider borate dielectric platform is oriented toward wide-band-gap, moderate-to-high permittivity candidates for GaN and SiC power-device passivation and advanced semiconductor packaging. In that application space, dielectric layers must tolerate the high electric fields characteristic of wide-band-gap power devices, must not introduce mobile alkali ion contamination (calcium is a fixed divalent cation, benign in this respect), and must be compatible with wafer-level integration temperatures. Calcium borosilicates are thermally stable to high temperatures and have no known mobile-ion contamination pathways, which is a favorable prior for the target application even before the dielectric tensor is computed.

The primary target markets are advanced semiconductor packaging dielectrics and passivation interlayers for GaN and SiC power devices — both segments growing at above-average rates as electric-vehicle powertrains, industrial motor drives, fast-charging infrastructure, and data-center power conversion shift from silicon to wide-band-gap semiconductor platforms. The power-device passivation dielectric market is embedded within the broader compound-semiconductor materials and packaging supply chain, which industry analysts broadly estimate in the several-billion-dollar range globally and expanding as GaN and SiC penetration of automotive and industrial power conversion accelerates. These are estimates, not audited figures, and the addressable slice for a novel crystalline borate dielectric would depend heavily on whether the material can be deposited at wafer scale by existing PVD, CVD, or ALD toolsets — a manufacturing readiness question not yet answered for Ca2B2SiO7 specifically. The customer logic, if the property gates close favorably, follows two paths. The first is licensing to integrated device manufacturers or materials suppliers who qualify new dielectric compositions for passivation stacks in GaN-on-Si or SiC power modules — companies that need clean-room-compatible, RoHS-compliant dielectrics with well-characterized permittivity and breakdown characteristics. The second is licensing to packaging materials suppliers developing advanced chiplet integration substrates, where low-loss, thermally stable dielectrics are needed between redistribution layers. In both cases, a royalty-per-wafer or royalty-on-material-supply structure is the natural licensing model, with the priority-date filing providing the leverage needed to capture value from compositions validated after the filing date. Because this asset is a backup arm rather than a lead composition, no specific addressable-market figure should be attached to it in isolation. Its commercial value is best understood as optionality within the broader borate dielectric platform: if the lead members encounter freedom-to-operate obstacles, manufacturing difficulties, or fail to meet specific property targets in a given device stack, Ca2B2SiO7 provides a documented, priority-dated, supply-chain-clean alternative that can be advanced to primary status without a new filing. That optionality has real value in a market where design cycles for power-device dielectrics span years and a one-year priority-date advantage can determine who captures the royalty stream on a given device generation.

genus completeness / priority preservation; supply-chain-clean phonon-proven backup, no asserted property advantage until DFPT-eps proof gate closes

recited as phonon-proven property-pending dependent backup; excludable by proviso under 6.3(d); inherits 7.16.7 phosphor/dosimetry/scintillator exclusions

The most natural acquirers or licensees for the borate dielectric platform — and for Ca2B2SiO7 as a supply-chain-clean backup member within it — are compound-semiconductor device manufacturers and advanced packaging materials suppliers who are actively qualifying new dielectric interlayer compositions for GaN and SiC power modules. This includes integrated device manufacturers in automotive and industrial power electronics, wafer-level packaging foundries expanding their dielectric material options, and specialty materials companies that supply passivation precursors or deposited dielectric films to the power-semiconductor supply chain. For these buyers, the supply-chain-clean profile of Ca2B2SiO7 (no restricted elements) combined with a documented priority date and phonon-stability credential represents a defensible starting point for a design-in qualification program — particularly if the DFPT property gate is closed prior to any acquisition conversation. A secondary buyer class is defensive acquirers: companies that hold or are building borate-dielectric patent positions and wish to consolidate genus coverage, or that want to ensure a supply-chain-clean alternative is within their portfolio should their primary lead compositions encounter regulatory headwinds. In this framing, the Ca2B2SiO7 backup arm has value even if it never becomes a primary product, because it extends the exclusionary perimeter of the broader borate dielectric genus at a well-defined priority date.

The central risk for Ca2B2SiO7 is the open dielectric property gate. Until the DFPT static dielectric tensor and band gap are computed, no specific permittivity, loss tangent, or leakage-suppression claim can be made — and without those values, the composition cannot be positioned competitively against incumbent Si3N4, Al2O3, or SiO2 dielectrics in any specific device qualification. If the DFPT calculation reveals ordinary or unfavorable permittivity (for example, a static dielectric constant below incumbent Al2O3 at comparable loss), the composition's commercial case weakens significantly, and it may remain a purely defensive genus-completion filing rather than a licensable product candidate. The roadmap to de-risk this is straightforward: commission the DFPT-eps calculation as the immediate next computational step, and follow with experimental thin-film synthesis and permittivity characterization to validate the computed values before any licensing conversation. A secondary risk is the narrow FTO position. Borosilicate space is crowded with prior art across optical, cement, and electronic substrate applications, and while the packaging-dielectric application context and the phonon-stability qualifier provide some differentiation, a buyer should commission independent patent counsel review before relying on Ca2B2SiO7 as a primary asset. The excludable-by-proviso structure mitigates this risk at the portfolio level — the backup arm can be dropped without damaging the lead claims — but a standalone licensing play on this specific composition would require a more thorough FTO clearance than is currently documented.