While a fear on usage of human toxicity like solder is increasing, there is also an interest on human toxicity of halogen flame retardant. Bromine based flame-retardant is widely used as the halogen based flame retardant due to the cost and the performance.
In many cases, the plastic components used for an electric device also use the bromine system flame-retardants for the flame retardant. Therefore, the change to an alternative material system is advancing. For example, it has started that changing the housing of the display monitor of a personal computer in the material, which does not contain bromine system flame-retardant.
The epoxy resin, the main material of the Multi-layer Printed Circuit Board, includes Bromination epoxy (TBBA) for flame retardant. Although bromination flame-retardants, such as PBB and PBDE's, were previously used in, TBBA was chosen as a safer substance from the problem of the toxic nature, and the change was performed in 1980s.
Bromination epoxy materials are made by reaction of a bromine compound and epoxy. German Environment Agency has announced that bromination epoxy is a safe material since the bromine element of the material does not fuse to a nature easily. However, the agency has not recommended the use the mixed material with a thermoplastic plastic.
On the other hand, Printed Circuit Board material suppliers has been developing new epoxy resin without TBBA in consideration of possibility of generating of the dioxin from TBBA when incinerating Printed Circuit Board Moreover, since it was declared that the 3rd edition of the draft of the WEEE would ban the use of halogen flame retardants, development of a material maker's halogen-free printed circuit board material was accelerated from 1998 to 1999.
As a result, each Japanese print board material supplier exhibited at the same time halogen-free printed circuit board materials in JPCA Show (Japan Printed Circuit Association Show) held in Japan in 1999. Moreover, some of the printed wired board suppliers announced the development of halogen-free printed wired board used the halogen-free material.
To such a material supplier's activity, as a set maker's activity, the notebook PC that adopted the halogen free board was put on the market from Toshiba Corp. in the end of 1998. Now, Hitachi, Sony and etc. have positively announced the adoption to the electronic products of a halogen-free board.
