UL 796-2020 pdf free download.Printed Wiring Boards.
1.1 These requirements apply to rigid printed wiring boards and flexible printed wiring board for use as components in devices or appliances. Compliance with these requirements does not indicate that the product is acceptable for use as a component of an end product without further investigation.
1.2 The flexible printed wiring boards covered by these requirements consist of conductors affixed to insulating base film, with or without a cover-lay film, with midboard connections.
1.3 These requirements do not cover flexible printed wiring boards of laminated-film construction in which the conductors are parallel to each other and are completely covered by the base film with only point-to-point end connections.
1.4 Flexible material constructions and multilayer rigid flex composite interconnect constructions with and without stiffener and adhesive materials shall be investigated in accordance with the Standard for Flexible Materials Interconnect Constructions, UL 796F.
2 Glossary
2.1 For the purpose of this Standard the following definitions apply.
2.2 ADDITIVE PROCESS — A selective or non-selective process used to deposit a pattern of conductor
material(s) on clad oc unclad base material.
2.3 ADHESIVE — A substance such as glue or cement used to join, bond, or fasten materials or objects
together.
2.4 AS RECEIVED — Specimens or samples in an unconditioned state, pnor to being subject to
conditioning, or without a history of conditioning.
2.5 BASE MATERIAL — An organic or inorganic material used to support a pattern of conductor material.
The base material may be rigid or flexible.
2.6 BASE MATERIAL THICKNESS — The thickness of the base dielectric material excluding conductive foil or material deposited on the surface of the base material. If an adhesive is used to adhere the conductor material to the base material, the adhesive thickness and application surfaces (base material sides) is indicated separately.
2.7 BLIND VIA — A via extending to only one surface of the board construction.
2.8 BLISTERING — Localized area of delamination. See 245, Delamination.
2.9 BONDING LAYER — An adhesive layer used to bond discrete layers of multilayer board constructions. Also known as Prepreg.UL 796 pdf download.