Issue link: https://iconnect007.uberflip.com/i/1236528
134 PCB007 MAGAZINE I APRIL 2020 The ALARP principle is that the residual risk shall be reduced as far as reasonably practi- cable. If the medical sector accepts this, we should be able to use this method for most of our PCBs for those gray-zone areas where the standard leaves customers and suppliers to find solutions themselves. As mentioned, IPC uses the term AABUS. If you read the IPC standard, you will find this term used all over, causing much frustration. Why Is This Important? We all want clear rules to avoid conflicts be- tween the customer and supplier; however, things are not always that simple. Some cases need to be discussed to be able to come up with good solutions. Often, the challenge can arise when the cus- tomer is not the decision-maker. The product owner has strict requirements, and to be on the safe side, the electronic supplier that as- sembles the PCBs prefers to be even a bit strict- er than their customer. Some might be reluctant to ask for approval of defects not directly mentioned in his cus- tomer quality requirements. That's when the acceptability grey zone develops to a challenge between the two. At the end of the day, the customer often wins these discussions, and we end up throw- ing away good products that could have been used. Can We Continue Wasting Good Products? In a world where a clean nature is getting in- creasingly rarer, we must look at every way to avoid pollution. Even if we are able to remove a lot of the toxic substances, we will never be able to remove all of them sufficiently. Elec- tronics with their bromides, heavy metals, and other substances harmful to nature will, from time to time, leak out. Of course, the challenge with throwing away fully functional electronics can be seen as a minor issue, when tons of plastic and electron- ics are thrown away by the consumers every day. Still, all efforts count. We have no good reason to waste good products. A Shout-out for a Greener World If all of us accept the risk level, such as the medical sector's ALARP, we should be able to reduce this unnecessary pollution by accept- ing minor cosmetic defects, as well as rework of minor solder mask defects, such as scratch- es, pinholes, and exposed copper. None of this increases the risk of failure in assembly or in the final application. I am not talking about defects that can affect soldering or product function. We should never jeopardize product quality. Cooperation and Improvement To improve today's situation, we need to jug- gle two thoughts at the same time: accept cos- metic defects (that are within IPC standards), but at the same time, talk with one another and find good solutions. We need to work with continuous improvements, use automatic screening tools, and accept rework before the boards are shipped. As an advisor between customers and PCB suppliers, I work with improvements every week. My target is to reduce such cosmetic er- rors to a minimum, but I still have to accept the fact that PCB production might involve cosmetic issues. In my opinion, the best way to avoid this is 100% automatic production and better cleanroom conditions. The ultimate scenario would be a production without the "green oil" (my Chinese friend's word for solder mask) that causes so many issues, but we are still years away from that. However, it's all about the baby steps toward better decisions, more knowledge around the level of acceptance of cosmetic failures, better guidelines, and—eventually—less scrapping of functional PCBs. After all, a small step toward a greener in- dustry is better than no step at all. PCB007 Jan Pedersen is a senior technical advisor at Elmatica. To read past columns or contact The PCB Norsemen, click here.