Samsung, one of the largest mobile manufacturer globally, went through very rough times after the launch of Galaxy Note 7. One after another report started pouring in of the Galaxy Note 7 catching fire. It became such a big mess that the company had to recall all of the Galaxy Note 7 smartphones from the market. It offered a refund as well as various discounts to Note 7 owners.
The official explanation from the company had been long overdue. And now, Samsung has finally revealed what caused the phone units to catch fire.
After a thorough investigation, the company found a couple issues, affecting different Note 7 versions — original unit and the replacement unit. The first batteries seem to be affected by a design flaw in the top corners. More specifically, the upper-right corner, which could come with abnormalities.
A protective layer is used to separate positive and negative electrodes and if this layer is damaged, the electrodes can meet and cause a short circuit. This seems to be one of the issues with the second batch. As per the company, the replacement batteries were affected by:
abnormally high welding bars that formed during the ultra-sonic welding process to attach the positive tab. Due to the high-welding bars, penetration of the insulation tape and the separator resulted in direct contact with the negative electrode. In addition, we found a number of batteries that were missing the insulation tape.
To present us with these results, Samsung went through a set of elaborate tests using nearly 200 thousand devices. They focused on feature abnormalities related to water resistance, fast charging, wireless charging, the iris scanner, software and the USB Type C.
However, none of these Samsung internal tests showed any issues. So they then went on to examine the production process and asked help from third-party investigators, including UL, Exponent, and TUV Rheinland AG. The third-party research firm UL reaffirmed that the root cause was the deformations in the upper corners of the battery, as well as a thin separator within the battery.
After this Note 7 debacle, Samsung has promised to adopt harsher preventive measures. The company is now gearing up with to launch its new flagship smartphone — Galaxy S8 in April this year. The Galaxy S8 is first expected to make an appearance at the Mobile World Congress next month.