I was just thinking what a wonderful world it would be if QMC didn’t have to worry about compliance with RoHS. QD Vision is currently filing for exemption and having to justify in length every reason imaginable why they should be granted an exemption. It appears everyone is on board but 3M and Nanosys. They bet the farm on CFQD. Every company has supported it but I didn't see QMC on the list. Why?
I looked up RoHS - Restriction of Hazardous Substances (RoHS)
The Reduction of Hazardous Substances (RoHS) regulations set limits for the following substances:
• Lead
• Mercury
• Cadmium
• Polybrominated Biphenyls (PBB)
• Polybrominated Diphenyl Ethers (PBDE)
To certify to the above compliances, these substances must not be intentionally added to the product AND cannot exceed the following maximum allowable levels as a trace substance:
0.1% (1,000 ppm) for: Lead*, Mercury, Hexavalent Chromium, PBB and PBDE
0.01% (100 ppm) for: Cadmium
These requirements must be applied at the homogeneous material level.
Too put it into perspective, think of a soldered joint, we have all seen them at some point. They are a drop of molten metal from a pin head to some pretty nasty looking amateur creations with flux stains. Each board could have a few, to hundreds of these beads of lead solder. Weight wise these drops containing lead start to add up and push them over the RoHS limits. Now look at a drop of QD’s in liquid form that are one QD in thickness, what would the coverage area be? Think of a drop of water or blood between two glass plates that are squeezed really tight. My unscientific result for a small drop yields a minimum coverage area of 1 sq in. ( I wasted a good drop of my Malibu Bay Breeze, I hope you appreciate that) In order to cover a 2.5” x 5” phone screen we would need 12 small drops.
1 drop equals .0648524ml or .06 grams or .72 grams at 12 drops per screen
• The iPhone 5S Weight:is 3.95 ounces (112 grams)
Now if a phone like the one I found having approximately the same dimensions, is only 112 grams total, the weight of quantum dots .72 grams as a component of the certified device, my math works out to <.01% at .006% That would be below the threshold for reporting the device outside the RoHS criteria. Given my unscientific method is off, you could probably get 2 sq. in. per drop and that would half the weight again.
Why would the competitions QD’s not meet RoHS and the Tetrapod QD will? The first thought that comes to mind is the aggregation on TQD’s is much better, resulting in less volume required and being more evenly distributed. That is a result of their tetrapod shape and having a very high quantum yield. Approximately 95% of the final product produced from the microreactors are TQD’s with the same characteristics and shape. The competitions yield is less, some as low as 40%. The last development for QMC is the most important, the license they acquired from Los Alamos National Labs (LANL) made it MOST DEFINITE they will use less TQD’s since the Giant-TQD (GTQD) are 10 to 100 fold brighter, stay on for 80% to 100% of the time (Non blinking) where all the competitions QD’s are blinking, on 20%, requiring more QD’s to be used and with less intense color . Does it mean we can use 80% less GTQD’s and achieve the same color intensity? I don’t know the answer to that from actual performance results but I’m sure you can use half the GTQD’s in display and medical products for the same or better results. Why didn’t QMC jump on the band wagon to throw support for exemption of the cadmium quantum dot limits? Is it because they don’t need too? JMO
Relaxing in Bermuda, that was until I started using this wifi that works sometimes and is slow as cold molasses. Frustrating to say the least. Time for rethink my priorities.
Bill
