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Experience of producing halogen free PCB From China factory

  • Jan 8
    According to jpa-es-01-2003 standard, copper clad plate with chlorine
    (C1) and bromine (Br) content less than 0.09% Wt(weight ratio) is
    defined as halogen-free copper clad plate.To get more news about Halogen Free PCB, you can visit pcbmake official website.

    1.2 why do we ban halogen

    Halogen refers to the halogen group of elements in the periodic table of
    chemical elements, including fluorine (F), chlorine (CL), bromine (Br),
    and iodine (1).At present, the flame retardant substrate, FR4, cem-3,
    etc., flame retardants are mostly brominated epoxy resin.Brominated
    epoxy resin, tetrabromobisphenol A, polybrominated biphenyl,
    polybrominated diphenyl ether, polybrominated diphenyl ether is the main
    resistance fuel of copper clad plate, its cost is low, compatible with
    epoxy resin.But research shows that institutional containing halogen
    flame retardant materials (polymerization polybrominated biphenyl PBB:
    polymerization polybrominated diphenyl ether PBDE), waste burning, emit
    two well English (dioxin dioxin TCDD), benzene furan (Benzfuran), such
    as large amount of smoke, smelled, highly toxic gas, carcinogenic,
    unable to discharge after intake, not environmental protection, affect
    human body health.Therefore, the European Union initiated a ban on the
    use of PBB and PBDE as flame retardants in electronic information
    products.The same document from the ministry of information industry of
    China requires that electronic information products put on the market by
    July 1, 2006, must not contain substances such as lead, mercury,
    hexavalent chromium, polymerized polybrominated biphenyls or polymerized
    polybrominated biphenylene ether.

    The eu law prohibits the use of PBB and PBDE and other six substances,
    it is known that PBB and PBDE in the copper coated plate industry has
    been basically not in use, more use is in addition to PBB and PBDE
    bromine flame retardant materials, such as tetrabromobisphenol A,
    dibromophenol, etc., the chemical formula is CISHIZOBr4.There are no
    laws and regulations on this kind of brominated flame retardant copper
    clad plate, but this kind of brominated copper clad plate, when burning
    or electrical fire, will release a large number of toxic gas (brominated
    type), the amount of smoke;When PCB is welded with hot air and even
    components, the plate is subjected to high temperature (>200) impact,
    will also release trace of hydrogen bromide;Whether dioxins are also
    produced is still being assessed.Therefore, FR4 plates containing
    tetrabromobisphenol A flame retardants are not currently prohibited by
    law and can still be used, but cannot be called halogen free plates.

    This paper discusses the processing characteristics and experiences of halogen-free PCB.

    1.3 principle of halogen-free substrate

    At present, most of the halogen-free materials are mainly phosphorous
    and phosphorous nitrogen systems.Phosphorous resin in the combustion,
    thermal decomposition to produce polyphosphoric acid, extremely strong
    dehydrating, the surface of the polymer resin to form a carbonized film,
    isolation of the resin burning surface and air contact, so that fire
    extinguishing, flame retardant effect.The polymer resin containing
    phosphorus and nitrogen compounds produces non-combustible gas when
    burning, which helps the resin system flame retardant.

    2 characteristics of halogen-free plate

    2.1 insulation of materials

    Since P or N are used to replace halogen atoms, the polarity of
    molecular bond segment of epoxy resin is reduced to a certain extent,
    thereby improving the insulation resistance and resistance to
    penetration.

    2.2 water absorption of the material

    As the N and P fox in N and P deoxidizing resins of nitrogen and
    phosphorus series have fewer electrons than halogens, the probability of
    forming hydrogen bond with hydrogen atoms in water is lower than that
    of halogen materials, so the absorbency of the materials is lower than
    that of conventional halogen flame retardant materials.For the plate,
    the low water absorption has a certain effect on improving the
    reliability and stability of the material.