Rice-husk-derived polymer composites for rigid printed circuit board substrates: protocol for a systematic review (retrospective deposit)

Protocol for a systematic review of rice-husk-derived polymer composites as rigid printed circuit board (PCB) substrates, covering dielectric, thermomechanical, environmental and application-readiness evidence. This protocol is deposited retrospectively. Database searching (eight databases, October 2026), deduplication, title/abstract screening and full-text assessment of 35 reports had been completed by one reviewer before deposit. Abstract screening of 27 title-only records, full-text assessment of 2 further records and independent second-reviewer verification will follow this protocol. The review was not registered in PROSPERO because it has no health-related outcome. Reporting follows PRISMA 2020 and the SWiM guideline. Funding: Riset dan Inovasi untuk Indonesia Maju (RIIM) programme, National Research and Innovation Agency of Indonesia (BRIN), contract 235/IV/KS/10/2025 and cooperation agreement 34/PL10.12/KS.00.00/PKS/2025.