There is also growing concern about halogen-related issues. For the printed circuit board (PCB) manufacturing industry—which uses a significant amount of chemicals—it is particularly important for PCB manufacturers to take effective measures to actively respond to society’s demands for environmental protection.
This article will take an in-depth look at the nature of the halogen issue, the reasons for implementing halogen-free manufacturing, and the relevant regulations and their provisions.
I. The Concept of Halogens
First, let’s take a look at the concept of “halogens.” This term originates from Greek and originally meant “salty ground.” In chemistry, the halogens—or the halogen group—consist of five chemical elements: fluorine, chlorine, bromine, iodine, and astatine. In the electronics industry, the primary focus is on bromine and chlorine.
II. Why Use Halogen-Free PCBs?
Why do we adopt halogen-free manufacturing? This is because electronic waste and plastic products containing halogens—such as PVC—contain halogen-based flame retardants. When these products are discarded and incinerated, they release harmful substances such as dioxins and acidic gases (HCl). These harmful substances can bioaccumulate, posing a threat to the environment and human health. The United Nations Environment Programme has classified these substances as persistent organic pollutants.
Halogens are widely found in printed circuit boards, solder masks, molding compounds, connectors, and other common electronic products. For example, halogen-containing flame retardants are used in printed circuit boards, and the toxicity of PBBs and PBDEs has raised widespread concern. When halogen-containing circuit boards and electronic products undergo incomplete combustion, they produce numerous byproducts, including dioxins and furans, as well as acidic or corrosive gases. These substances pose potential hazards to both the environment and human health. Therefore, to mitigate these potential risks, it is necessary to adopt halogen-free materials.
Halogen-free manufacturing not only reduces environmental pollution caused by electronic products but also effectively protects human health. This approach represents yet another green revolution in the electronics industry since the implementation of the RoHS (Restriction of Hazardous Substances) Directive on July 1, 2006. Compared to the hazards posed by halogens, the six hazardous substances restricted by the RoHS Directive—such as lead, cadmium, mercury, hexavalent chromium, polybrominated diphenyl ethers, and polybrominated biphenyls—pose even more serious risks. These substances pose a threat to the human central nervous system, skeletal system, respiratory system, and the environment.
III. Halogen-Free Regulations and Their Provisions
To standardize halogen-free manufacturing, various industry standards and regulations have established a series of requirements. In accordance with the requirements of IEC 61249-2-21, clear specifications have been established for the manufacture of printed circuit boards using halogen-free materials, stipulating the maximum halogen content in electronic soldering materials, resins, and reinforcing materials, typically measured in ppm (parts per million). According to different standards, the acceptable halogen content is as follows: 900 ppm for bromine, 900 ppm for chlorine, and a maximum total halogen content of 1,500 ppm.
Various organizations and committees, such as the IPC Low-Halogen Electronics Standards Working Group 4-33A and the JEDEC JC14 Committee, require that PCB substrates meet the low-halogen (bromine and chlorine) requirements defined in the IPC-4101B standard. At the same time, the RoHS Directive is undergoing continuous revisions to ensure compliance with the electronics industry’s requirements for halogen-free manufacturing.
In short, halogen-free manufacturing has become a green revolution in the electronics industry, with positive impacts on both the environment and human health. Halogen-free manufacturing not only helps reduce pollution but also helps meet strict environmental regulations, ensuring a healthier and more sustainable life for us all.
Frequently Asked Questions
1. What are halogens?
Halogens refer to the chemical elements fluorine, chlorine, bromine, iodine, and astatine, which play a significant role in the electronics industry.
2. Why adopt halogen-free manufacturing?
Halogen-free manufacturing helps reduce the potential harm that electronic products pose to the environment and human health, and minimizes pollution.
3. What are the regulations regarding halogen-free materials?
Halogen-free manufacturing is governed by various industry standards and regulations, such as IEC 61249-2-21 and the RoHS Directive.
4. What are the advantages of halogen-free manufacturing?
Halogen-free manufacturing helps improve the environmental performance of electronic products, reduce the use of hazardous substances, and protect the environment and human health.
5. How can compliance with halogen-free manufacturing be ensured?
Comply with relevant regulations and standards, such as the requirements of the IPC Low-Halogen Electronics Standards Working Group 4-33A and the JEDEC JC14 Committee, to ensure compliance with halogen-free manufacturing.
