RoHS Compliance for Liquid Crystal Displays
Focus Displays offers LCDs that conform to ROHS (Restriction of Hazardous Substances Directive) requirements.
The whole idea behind RoHS was to keep key elements (chemicals) out of our landfills. It makes sense since the average life-span of consumer electronics is 4.7 years.
So what is ROHS and how did it come into being?
WHAT IS ROHS?
RoHS is fairly new and has only been around since 2003, with its implementation in 2006; the directive became law in all member states in the European Union, as of July 2006. The idea behind RoHS was to restrict hazardous materials, specifically six known substances in the manufacturing of various types of electronic and electrical equipment known to cause problems. Since then, the list of substances has grown to 10. The 10 restricted substances are the following:
- Hexavalent chromium
- Polybrominated biphenyls
- Polybrominated diphenyl ether
- Bis(2-ethylhexyl) phthalate
- Butyl benzyl phthalate
- Dibutyl phthalate
- Diisobutyl phthalate
PBB and PBDE are flame retardants used in several plastics. Hexavalent chromium is used in chrome plating, chromate coatings and primers, and in chromic acid. These substances are in many small and large household appliances, IT & Telecommunications, consumer, lighting, toys & leisure, and sports equipment, automatic dispensers, and semiconductor devices, to name a few. The compliance does not include fixed industrial plant and tools.
ROHS GREEN INITIATIVES WORLDWIDE
As you can see, these six substances are found in numerous products and therefore have raised much concern over their safety. Yet, in the states, California was the first and only state to implement RoHs, taking effect on January 1, 2007; however, SB20 only applies to CRT, (Cathode Ray Tube) LCD, and plasma screens larger than 4 inches measured diagonally. Worldwide, only five other countries have adopted it: China, Japan, Korea, Norway, and Turkey. These countries took action as early as 2000 and as late as June of 2015. In taking this approach, it would reduce the effect of hazardous materials being used in manufacturing of products. Each of these laws is in accordance to the compliance of RoHS, but has their own, unique initiative adopted.
More states are starting to come on board with their own legislation that is similar to RoHS, with other countries, such as Iceland and Switzerland having adopted similar legislation with more countries following lead.
ISSUES WITH SOLDERING WITHOUT LEAD
To meet compliance for RoHS, manufacturers started removing lead from solders a few years ago, but many customers, such as the military and aviation are not required to honor RoHS and have continued the use of lead. However, for the manufacturers who have removed the material, there hasn’t been much difference, and in fact, have said removing the lead could cause solders to crack. Without lead though, the tin, (substance usually substituted for lead) has higher melting points and inferior wetting properties, according to Dr. Paul Goodman, ERA Technologies Ltd. He also stated that utilizing tin instead of lead could result in component damage. Poor wetting can occur if surfaces are not clean or oxidized enough. The same is true, even with tin, but is worse with lead-free.
Still, there are many companies that give customers the option of lead-free products, so the question becomes, Has RoHS been bad or good, and has it made much of a difference?
ENVIRONMENTAL & HEALTH IMPACT ON ROHS IN MANUFACTURING
Since RoHS has taken effect, there have been some case studies that have solidified its importance in the environment and safety protocols in regards to manufacturing products. Keep in mind, the cost of substituting different substances, such as lead, is minimal, so that should be a non-issue.
In one such study, the EPA has published a life-cycle impact assessment of lead-free or lead-tin solders, in regards to the environment, and concluded that lead-free or at least a combination of lead with another substance had the least impact on the environment. The tin/copper alternative had the best rating or lowest scores of environmental impact. For paste solders, bismuth/tin/silver had the lowest impact scores.
Not only was it best for the environment, but also had an impact on people’s health, particularly in third-world countries where many high-tech “trash” ends up. For the electronics industry, workers had an immediate benefit, such as better immune response, heathier kidneys, lungs, liver, lowered anemia, hypertension, and gastrointestinal issues, as well as lowered incidence of some cancers.
In the long run, it looks as if the RoHS initiatives or similar legislation, in which several countries have now implemented or is in the process of implementing, has indeed made a positive impact. And because many companies have manufactured alternative substances, it gives you the option of deciding what is right for you.
SO WHAT DOES ROHS HAVE TO DO WITH LCD DISPLAYS?
We have customers that would prefer to return to the old days of lead in the solder and components. Some of their reasons include a lower melting temperature and less chance to damage sensitive components such as TFT (Thin film Transistor)
These customers feel that there will be long term reliability issues with products that are in the field after several years. In fact, many of our customers build products that will be in the field for many years. They would prefer to move away from the RoHS requirement, but many countries will no longer accept non-RoHs products.
There has been some belief that the solder will crack after a few years of use in regions where the temperature fluctuate between freezing to hot and then back. Components need to be able to bend and ROHS may not allow this flexibility.
Industries that are exempt from ROHS including: aviation, military and medical.
So RoHS a concern for reliability of such products as cell phones, tablets, watches and microwaves since most of these products will be in the landfill within a few years after they are manufactured?
Even when the economy is poor and money is tight, people may hold on to some items a bit longer, but I don’t see people holding on to their cell phone or microwave for ten or more years. After all, the majority of consumer items are no longer repaired. They are just ‘tossed away.’