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December 24, 2024 - Updated March 11, 2012 - Originally Posted Bromine Free PWBs
What are the pros and cons of bromine in PWBs?Several of our customers require bromine free PWBs, but some of our suppliers do not think that is a good way to go. Are bromine and lead free connected?
E.C.
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Bromine and lead free are both pseudo environmental specifications for electronics. Lead was required to be eliminated in electronics by the European Union RoHS Directive and other similar regulations because of (unproven) concerns regarding potential human exposure to the lead in electronics. Although there are no laws requiring removal, some OEMs are specifying bromine free electronics because of environmental concerns related to dioxin formation during improper combustion of waste electronics. The main use of bromines in circuit boards if for flame retardancy. Removal of bromine requires the use of other flame retardants which can affect certain performance parameters and price.
Director, Government Relations and Environmental Policy, IPC
Fern Abrams is the Director of Government Relations and Environmental Policy for IPC. She is responsible for advocating member positions in the areas of environment, health and safety, tax, trade, intellectual property and other regulatory issues. Current activities focus on conflict minerals regulations; implementation of best practices for protecting intellectual property, research and development tax credits, international materials restrictions, hazardous waste, and environmental reporting and record keeping.
I am not a PWB expert but the low halogen push is from NGOs (nongovernment organizations) push to remove the BFR and CFR types of flame retardants.They demonstrated electronic products are being burned to gather the metals out of them in improper recycling (open pits) processes by kids and older folks that is very harmful to the people and environment. If recycled properly, this is not an issue. These materials are definitely a great benefit for the products they are used concerning flame retardency. There are no laws banning their use, but it is an industry push to be "greener"from mostly OEMs being pressured by NGOs. The OEMs in turn have put pressure on the supply chain and several have it written in the contracts /stated on their websites that their products are low halogen. Are bromine and lead connected? Yes, both are (were) commonly used in electronic PWBs / components and were safe for use. Both are/were the lowest cost solutions. Changes to both have costs millions(billions?) to replace. Cost increases include
Mark Frimann Product Stewardship Management, Texas Instruments
Mark Frimann has been working in electronic industry regulations and standards on chemical and material restrictions, and how this is dealt with in the supply chain, and addressing on-going issues as these requirements change and become further defined.
Most encapsulent materials previously contained Bromine (halides) as a fire retardant filler. New "Green' materials contain no Bromine containing compounds. In general they have been an improvement and copper ball bonding actually has better reliability with specifically formulated (for copper) "Green" encapsulents.
President, Consultant, Process Solutions Consulting Inc.
Lee Levine has been a Process Engineer and Metallurgist in the semiconductor industry for 30 years. He now operates his own company Process Solutions Consulting Inc where he consults on process issues and provides SEM/EDS and metallography services.
Bromine-free (or more properly known as "Halogen-free" or"Low-Halogen") and Lead-free are not connected. Lead-free requirements are related to the EU RoHS Directive and the restrictions on the use of lead in electronics. The push to eliminate halogens (specifically bromine and chlorine) is from OEM customers who are getting pushed by Non-Governmental Agencies (NGOs) to make their products more "green."The definition of "Low-Halogen" for Printed Boards is contained in IPC-4101 (see the latest revision), and is defined as:
Most of the laminate and prep reg suppliers in the industry do have low-halogen products. These products may be based on bismaleimide-triazine or other resins that use metal hydroxides for flame retardancy. The processing characteristics of these prepregs and laminates will probably be different than the brominated epoxies used by the requester. Companies switching to halogen-free materials should work closely with their suppliers to characterize the process for manufacturing Printed Boards using the new materials. A great place to learn more about this issue is the IPC web page on Halogen Free and Brominated Flame Retardants at: http://www.ipc.org/ContentPage.aspx?pageid=Halogen-Free-and-Brominated-Flame-Retardants.
Corporate Product Compliance Manager, TriQuint Semiconductor, Inc.
John has focused on Product Compliance and Environmental & Safety issues throughout his career. He has a B.S. in Chemical Engineering, an M.S. in Chemical Oceanography, an M.S. in Environmental Engineering, and is a Professional Engineer in the fields of Chemical and Environmental Engineering.
Bromine and lead-free are connected, in some ways,because both are targeted by the RoHS legislation. Bromine itself it not specifically targeted, but there are two common Brominated flame retardants that are used in circuit boards that are banned by RoHS. As a means of simplicity and ease of testing, many have decided to eliminate all Brominated compounds from circuit boards and other process materials. (XRF is commonly used to test for the offending Brominated flame retardants, but XRF can only measure Bromine level, but not specific Brominated chemical compounds.) As to pros and cons, the pros for the Brominated flame retardants is that they are well established and understood in the market and carry no price premium. But since they are hard to test with existing equipment (again, XRF), they are being banned in favor of Bromine-free varieties. These Bromine-free flame retardants are not as well understood in the market, but the learning curve is swift and shouldn't present a major hurdle. There may be a slight price premium for these changes, so consult with your board vendors to verify this.
General Manager - Electronic Assembly Americas, DEK International
Mr. Smith has been supporting customers in the electronics assembly industry since 1994. His expertise is focused on solder paste printing and reducing soldering defects. He holds a BS in Chemical Engineering and an MBA in Marketing. He has authored several papers in trade magazines and at industry conferences. He is an SMTA Certified Process Engineer.
Bromine-free and Lead-free are connected via the RoHS initiative.Brominatedhydro carbons such as PBE and PDBE have traditionally been used as flame retardants. The RoHS initiate calls for elimination heavy metals in electronics essentially banning use of PBE and PBDE. Bromine-free is defined as <1,000 ppm or 1,000 mg/Kg Lead-free is defined as <1,000 ppm or 1,000 mg/Kg
Global Sales Director, Photonis USA
Mr. Greenland has 20 years electronics industry experience ranging from circuit board design to product support & repair services. Peter has spent the last 4 years at Pycon Inc. supporting customers that require high mix, low volume manufacturing solutions.
Bromine complexes, primarily tetrabromobisphenol-A (TBBA), has been used as a flame retardant material for many years in laminate materials. The FR in FR4 stands for Flame Retardant. Many epoxy laminates have this material bound into the chemical matrix.The move to halogen-free materials is the result of fear-mongering, science hating, groups which deem all halide materials as bad. Consequently, much environmental legislation is aimed at reducing halides in laminates. The pros of bromine additives: they work, they are chemically stable, and they are not ahazard to the environment or the people who work with them, at least inlaminate form. The cons relate more to those workers in the chemical industry who deal with high concentrations of bromine. Halogen-free laminates (which are not really halogen free) use alumina or magnesium salts to replace the bromine compounds. They are not as effective as the brominated compounds, and result in other undesirable effects, such as pad cratering. I would go back to your customer and ask why they require bromine-free PWBs? Is it a regulatory/legal requirement, or are they just jumping on the halogen-free bandwagon?
Principal Materials and Process Engineer, Collins Aerospace
Doug Pauls has a bachelors in Chemistry & Physics, Carthage College, BSEE, Univ of Wisc Madison. He has 9 years working experience for US Navy - Materials Lab, Naval Avionics Center Indianapolis. 8 years Technical Director, Contamination Studies Laboratories. 11 years Rockwell Collins Advanced Operations Engineering.
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