Halogen-Free Assembly Blog

By Tim Jensen

Check out the IPC website to hear me discuss halogen-free challenges. I review many of the things that I have discussed in previous blog entries.

Click here for the link: IPC Podcast

Have a listen and let me know what you think!

As I discuss the differences between “halogen-free” and “halide-free” with respect to solder pastes and fluxes for electronics assembly, I struggle to explain it in a concise manner without going too deep into chemistry. To follow is now how I explain the differences.

The term halide-free was developed many years ago by the IPC when no-clean fluxes were created. It is well known that halide ions can cause catalytic corrosion which will cause an electrical failure in an electronic device. Therefore, you do not want halide ions floating around in the flux residue on the board. Halide ions are a result of using a compound containing Cl, Br, F, or I with an ionic bond. Ionic bonds are easily broken creating the halide ion (i.e. Cl-). The IPC J-STD-004 has a test that ensures that the flux does not contain an ionically bonded compound containing Cl, Br, F, or I.

Halogen-free was developed as a result of environmental concerns with Cl and Br. Today, most definitions of halogen-free for electronics are only incorporating Cl and Br. However, it includes all forms of Cl and Br and not just the ionically bonded ones tested by the IPC. Using the EN14582 test method, it is easy to test for all forms of Cl and Br.

Therefore, a material that is halide-free per the IPC J-STD-004 may not actually be halogen-free. The halogen-free definition is much more stringent.

I recently attended and spoke at the IPC’s conference in Boston titles “It’s Not Easy Being Green.” There was tons of useful information and the attendence was great (200+). One thing that I felt would be useful to share was feedback relative to what two major OEMs are planning for their halogen reduction plans in an effort to become more “green.”

Lenovo: Phase out BFR’s and PVC on select models starting in 2009. They are also restricting red phosphorous flame retardants.

Apple: Restricting all Br and Cl for all new products beginning in 2009.

This shows that the industry is still divided on how to deal with halogens. The Lenovo approach is to focus on the materials of greatest concern. This is less restrictive, but is more difficult to test for individual BFR’s. Apple decided to eliminate all Br and Cl. This means a more difficult process of eliminating materials, but a simpler test and verification process.

The drama continues…