IEC 61249-3-3:1999 pdf download.Materials for printed boards and other interconnecting structures
1 Scope
This part of IEC 61 249 gives requirements for flexible polyester (PETP) films coated on one side or both with polyester, acrylic or epoxide type adhesive for use in the fabrication of flexible printed wiring. Films coated on only one side are used as a coverlay or covercoat in the fabrication of flexible printed wiring. This coverlay or covercoat is also used to provide local support to areas subjected to mechanical or environmental stress. Films coated on both sides are used as bonding films in the fabrication of 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 amend- ments 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 61 1 89-2:1 997, Test methods for electrical materials, interconnection structures and
assemblies – Part 2: Test methods for materials for interconnection structures
3 Materials and construction
The material consists of an insulating flexible film base of polyester (PET) coated with an
adhesive on one side or both sides.
3.1 Insulating film
Polyester films of preferred thicknesses and permitted tolerances are given in table 1 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.
Other thicknesses may be used by agreement between purchaser and supplier. The maximum permitted tolerances of such thicknesses shall be those of the nearest greater thickness stated in table 1 .
6.2.1.1 Specimens from cover sheets
Test specimens shall comply with the requirements of IEC 61 1 89-2 (see annex A). They shall be cut from a set of samples prepared by laminating copper foil to the film material under test. Laminating conditions should be agreed upon between purchaser and supplier, and should comply with the material manufacturer’s recommendations regarding pressure, temperature and pressing duration. The copper foil, as used in the fabrication of copper-clad laminates, 2 side to the adhesive layer. If any argument arises in relation to the laminating conditions, it is desirable to apply the standard procedures and conditions in the relevant test method specification (see IEC 61 1 89-2) by agreement between purchaser and supplier. NOTE When the release or protective materials are peeled off from coverlay films with punched holes and/or slits for further fabrication processes, careful attention should be paid in order to avoid deformation of the film due to any excessive peeling force.
6.2.1.2 Specimens from bonding films
The required test specimens, according to the relevant clause of IEC 61 1 89-2, shall be cut from a set of samples prepared by laminating copper foils to both sides of the film material under test as described in 6.2.1 .1 , except for peel strength and heat shock testing. For peel strength and heat shock testing, the samples shall be prepared by laminating a single-sided copper-clad epoxide/glass laminate on one side of the adhesive coated bonding film, and an unclad epoxide/glass laminate with a thickness not less than 0,5 mm on the other side, as described in 6.2.1 .1 . Two sets of samples shall be prepared: one with the copper foil facing side 1 of the bonding film, one with the copper foil facing side 2 of the bonding film.
IEC 61249-3-3:1999 pdf download
