IEC 61249-3-5 pdf download

IEC 61249-3-5 pdf download Materials for printed boards and other interconnecting structures – Part 3-5: Sectional specification set for unreinforced base materials, clad and unclad (intended for flexible printed boards) – Transfer adhesive films
1 Scope
This part of IEC 61 249 gives requirements for transfer adhesive films for use in the fabrication of flexible multilayer boards or flex-rigid printed boards.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 61 249. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of IEC 61 249 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 60249-1 :1 982, Base materials for printed circuits – Part 1 : Test methods
IEC 60249-2-8:1 987, Base materials for printed circuits – Part 2: Specifications – Specification No. 8: Flexible copper-clad polyester (PETP) film
IEC 60249-2-1 3:1 987, Base materials for printed circuits – Part 2: Specifications – Specification No. 1 3: Flexible copper-clad polyimide film, general purpose grade
IEC 60249-2-1 5:1 987, Base materials for printed circuits – Part 2: Specifications – Specification No. 1 5: Flexible copper-clad polyimide film of defined flammability
IEC 61 1 89-2:1 997, Test methods for electrical material interconnection structures and assemblies – Part 2: Test methods for materials for interconnection structures
3 Materials and construction
The materials consist of adhesive layers based on B-staged epoxide, acrylic or polyester (PET) resin supported by a removable paper carrier and protected by a polymeric release film which shall adhere until lamination. The adhesive on epoxide or acrylic base shall be compatible with the copper-clad polyimide films according to IEC 60249-2-1 3 and IEC 60249-2-15; the adhesive on polyester (PET) base shall be compatible with the copper-clad polyester films according to IEC 60249-2-8.
The thickness of the adhesive films shall be between 1 2,5 m and 75 m, with a permissible tolerance of ±20 % when measured by the method of 3.1 4 of IEC 60249-1 , provided that the micrometer used is capable of resolving 0,002 mm or better. Preferred thicknesses are 25 m and 50 m.
Other thicknesses may be used by agreement between purchaser and supplier.
The thickness of the adhesive film is defined as follows:
T a = T t – T p