If you notice, the color of most printed circuit boards is green. The unfortunate fact is that nothing is green about them. The truth is that, waste from PCB generated decades back will keep harming our environment for years. This pcb waste, which is made of hazardous substances that includes heavy metals like mercury, lead, cadmium and many other chemicals that affects human health and life adversely.
This is why environmental manufacturing is necessary for RoHS compliant PCB assemblies across all consumer electronics. RoHS (Restriction of Hazardous substances) helps in restricting manufacturers from making use of any hazardous material, most especially those found on electronic and electrical components.
Furthermore, in 2002, the European Union instigated this RoHS directive, which is under the directive 2002/95/EC. Regarding the initial directive, there are six substances that are hazardous and have been prohibited from use in packaging electronic circuits and electrical products.
As of today, the RoHS directive has seen two upgrades, which includes the RoHS 3 and RoHS 2. The release of the latter, which is also Directive 2011/65 /EU, was back in 2011. That of Directive (EU) 2015/863 was released back in 2015. Also, under this new directive (EU) 2015/863, there were four more elements added to the initial restricted elements.
What Does it Mean to be RoHS Compliant?
The parliament of the European Union back on 27th Jan 2003 passed two laws or legislations, which had an impact on the electronics industry. First, was the WEEE (Waste Electrical and Electronic Equipment), which makes the manufacturers responsible for disposing of waste of finished goods. Furthermore, the second legislation is much more important. This refers to RoHS (Restriction of Hazardous substances).
With this RoHS directive, it is illegal if you manufacture electronic or electrical equipment containing restricted materials, as well as materials that can harm the environment. This legislation took effect on 1st July, 2006. Also, the focus of this directive is on the smallest possible RoHS material or homogeneous part, which you can separate from an assembly or component mass.
Specifically, the electronic or electrical equipment that enters the European Union market cannot have cadmium, mercury, lead, polybrominated diphenyl ethers, specifically Octa PBDE and Penta PBDE or polybrominated biphenyls, and hexavalent chromium.
Materials that are Restricted Under the RoHS Compliance
Six major materials cannot be used in PCB due to the restriction caused by RoHS compliance. These include Lead, Mercury, polybrominated biphenyls, Hexavalent Chromium, polybrominated diphenyl ethers, and phthalates like DIBP, BBP, DEHP, and BBP.
This compliance specifies the highest levels these materials can be in a PCB as well as other electronics.
- Mercury < 100 ppm
- Cadmium <100 ppm
- Lead <1000 ppm
- Hexavalent Chromium <1000 ppm
- Polybrominated Biphenyls <1000 ppm
- Polybrominated Diphenyl Ethers <1000 ppm
- Benzyl butyl phthalate <1000 ppm
- Diisobutyl phthalate <1000 ppm
- Dibutyl phthalate <1000 ppm
- Bis (2-Ethylhexyl) phthalate <1000 ppm
What are the Impacts of RoHS Compliant PCBs?
As of 1st July 2006, the new electronic and electrical equipment hoping to enter the SU market, must not have cadmium, mercury, lead, polybrominated diphenyl ethers specifically Octa PBDE and Penta PBDE or polybrominated biphenyls, and hexavalent chromium. Below are other impacts of ROHS compliant PCBs.
Lead-free manufacturing
Though there is no restriction in the use of flame retardants in laminates, this lead-free initiative will also affect the supply chain. This means that manufacturers of lead free PCBs will not be able to make use of RoHS compliant surface finishes. Also, during assembly, lead solder must not be used.
For this reason, lead-free soldering will need a higher temperature before it can solder, while the raw PCB must have the ability to withstand higher temperature. Furthermore, new laminates will require better thermal and mechanical properties to be able to withstand any lead-free manufacturing, with respect to long-term stability and infant mortality.
Material restriction with respect to RoHS directives
The ROHS 3 directive bans the use of some hazardous elements, about ten in number. This is useful in electrical and dedicated service electronic products as well as high performance electronic products. In addition, the chemicals and substances used during PCB assembly and PCB manufacturing must not have these elements even in impurity form.
The quantity permitted in impurity form is determined in the RoHS directives. Take for example, the amount of cadmium you can have is restricted to 0.01% in impurity form.
Implementation Cost
When considering the protection of the environment, as well as our future as humans, cost isn’t a problem. However, we should understand what is involved when implementing RoHS. All lead-free solder will cost a minimum of 20% more compared to lead soldering.
Don’t focus on the cost of the material alone, there will also be an increase in energy cost. Regarding lead-free soldering, there is a need for higher temperatures for reflow soldering. As regards the cost for training the personnel to handle the lead-free environment change, there is a huge cost as well.
Some lead-free materials will include patent licensing costs, whether by the solder manufacturer or end-user. Also, there is a high cost to refine lead-free materials like gallium, indium, bismuth, and silver.
Reliability Concerns
The change of solder and materials so as to accommodate lead removal needs reliability testing. Techniques, models, and criteria for reliability testing must be refined so as to match the properties of lead-free assemblies. Below are some other concerns
Tin whiskers
Whiskers could result in short PCBs. This problem could become very serious because a good number of component manufacturers make use of pure tin as their lead finish to help in minimizing costs.
Solder joint reliability
The reliability of lead-free joints is less in contrast to lead soldering. Majority of researchers have discovered the long-term reliability of the solder joint is less compared to the lead/tin solder paste.
Higher-temperature soldering
An increase in soldering temperature will lead to a reduction in the components’ life, multilayer PCB delamination, thermal fatigue, etc.
RoHS standard (IPC-A-610)
This is electronic assemblies’ acceptability. This standard comes with approved and industry-developed programs such as instructional material, certification, and training. Companies providing RoHS compliant PCBs should have IPC trained workmen to offer the right attention to the necessary changes, as well as renewed criteria for inspection.
Solder Flux
The fact is some solder flux utilized for tin or lead cannot resist high temperatures. For this scenario, if we are making use of that same flux utilized for the lead, then it must evaporate, oxide, or decompose before the fluxing can happen. Therefore, this lead-free solder flux has to be designed in order to withstand any higher temperature.
Why is RoHS Compliant PCB Necessary?
The major concern starts with the electronic waste piles which are usually seen in junk yards that are open across the globe. This electronic waste is usually made of hazardous substances like heavy metals, as well as other chemical materials having no chemical control.
This problem further persists as this acidic rainwater will dissolve the lead as well as other negative and harmful substances. The contaminated rainwater is then added to the bodies of water. Therefore, this can cause severe harm to humans and aquatic life.
Also, heavy metals such as mercury and lead affect the human organs adversely. This could even disturb the whole central nervous system. Also, the metals affect how the reproductive system and the kidneys function. Taking high amounts of lead through a contaminated water source will surely reduce the time of reaction to the body organs like ankles, wrists, and fingers.
With the RoHS initiative, we all get some relief. Complying with the RoHS directives will ensure the fight against global warming and climate change.
RoHS Compliant Printed Circuit Boards
RoHS Compliant Printed Circuit Boards lack hazardous substances and chemicals. Also, RoHS compliant printed circuit boards are now in high demand as a result of the increasing preference towards circuit boards that are environmentally friendly.
This rise in demand for manufacturers adhering to RoHS compliance requirements for their printed circuit boards is as a result of the strict government policies and customer demands. We are beginning to witness a shift with respect to environmentally-responsible manufacturing all through the globe. In addition, RoHS compliant manufacturing helps in reducing the ill-effects that could come to workers when manufacturing is on.
What are IPC Standards?
These IPC standards are different from the RoHS standards. IPC is an association that produces standards related to printed circuit boards. This association was initially referred to as the Institute for Printed Circuits and this is where the IPC acronym came from. Even though it retained this acronym, it is now called Association Connecting Electronics Industries.
IPC is an association for the international industry that consists of over 4000 companies that makes, uses, specifies, and designs printed circuit boards (PCBs) and other assemblies including:
- Telecommunication industry
- Medical devices and equipment
- Industrial equipment
- Computer
- Automotive
- Military and aerospace
- Advanced microelectronics
Furthermore, these IPC standards are standards adopted in the electronics industry for electronic assembly, PCB manufacturing, and design. For all steps of the design, the production, and the assembly or printed circuit boards, there is always an IPC standard.
Conclusion
Here comes the end of our article on the different standards used in the electronics manufacturing industry. Any questions, please ask us immediately.
