Electric vehicles are practically computers on wheels. New innovations such as active and passive safety systems, electric propulsion, and semi and fully autonomous vehicles have all contributed to an increase in the usage of electronics in automotive applications. More importantly, automotive designers must still adhere to the same size and packaging constraints to ensure vehicles’ size and weight does not increase. To resolve this dilemma, automotive designers often rely on components being tightly placed on both sides of the Printed Circuit Board (PCB) to ensure the most efficient use of board space.
Many companies work together to design electronic systems. During the qualification process, there is a lot of back and forth between the final users (mostly OEMs or manufacturers) and the suppliers. In the ideal world, the more information that is shared between both parties, the more likely they are to produce reliable and safe products. In reality, two companies can’t openly share all the design details due to intellectual property considerations. The circuit card designer does not want to share the board details with a prospective customer. Simultaneously, to protect new product ideas, the systems integrator may not want to share use environment details with the board designers. The need for both parties to protect their IP and stay competitive makes it hard to collaborate.
One of the key problems in today’s electronics industry is the constant changes in needs and deliverables. Today’s electronic devices are smaller and faster and are constantly exposed to changing environmental conditions. With more people putting electronics closer to a human body in the form of wearables such as iPhones, Fitbits, or heart monitors, electronics designers and manufacturers need to ensure the safety and reliability of these devices to avoid costly mistakes.
Here, at DfR Solutions we work with hundreds of electronics manufacturers across industries and have noticed an increasing number of companies reporting early life failures in the field or unexpected failures in tests due to solder fatigue. They're noticing that the classic solder fatigue calculation models do not seem to capture all the possible risks of failure.
Since the first pedestrian fatality due to an autonomous vehicle in March 2018, there’s been no shortage of discussion and debate over the future of autonomous vehicles and AV testing.
However, as Dr. Craig Hillman discusses in this month’s issue of SAE’s Autonomous Vehicle Engineering, there’s a critical piece missing from that conversation: the interconnected roles of reliability and safety. In many companies, there tends to be a disconnect between the two departments. And because authority and responsibility (i.e., who does what and who reports to whom) can have such a dramatic impact on hardware and software design cycles, keeping these two departments in silos can have negative effects.
It seems like a month does not go by, without hearing news reports about battery explosions in e-cigs, headphones, smartphones or other electronic gadgets. Granted that stories about explosions are considered newsworthy, but has the statistical rate of battery failures actually gone up in the last few years? Has the impact of battery failures increased and if so, why? And, I am of course talking about Lithium ion batteries, the go-to battery chemistry in rechargeable electronic devices owing to their high energy density. I am certain you do not want to be carrying around a brick for a smartphone.
In recent years the practice of buying spare e-cigarette batteries online has started to increase, with some users scouting for higher amp-hour/power batteries in order to get a better vaping experience. This is particularly true for mechanical mod e-cigs, which are highly customizable and do not use protection circuitry. The battery protection circuit is what keeps a lithium-ion battery within its operating window, and prevents it from overheating, overcharge and other potentially dangerous situations.
My cousin recently came to me with a battery problem. He got a drone for Christmas, and he had not opened it for a while. "Last Christmas, right?", I asked. Apparently, it was the Christmas before (i.e a year and a half of being in a box). "Uh-oh," I say. I almost knew what was coming. The drone obviously did not work, and I got to see a picture of a very bloated Lithium Ion pouch cell. Your Lithium-Ion battery does need some attention from you every few months in the form of a periodic recharge, or you will end up with a cell that looks like the image below. (My colleagues have brought me plenty of gadgets with the plastic case popped open from a bloated battery)
“After a failure” investigations are typically performed to identify root cause of failure, calculate risk exposure and develop mitigation and remediation solutions. Just like with “before a failure” investigation, there are two specific test methods that could be applied to either of the two categories – non-destructive physical analysis (NPA) and destructive physical analysis (DPA).