By Robert Goodney, Quality Manager, Electronic Manufacturing Solutions (EMS)
On 25 July 2000, Air France Concorde Flight 4590 had just taken off from Charles de Gaulle Airport, Paris when it crashed into a hotel in nearby Gonesse. All 109 people on board and four people in the hotel were killed.
But how did this happen?
A titanium alloy strip about 17” in length and 1.3” wide had fallen from another aircraft, landing on the runway. Moments later, Flight 4590 ran over the debris during take-off, blowing a tyre and puncturing a fuel tank. The subsequent fire and engine failure caused the aircraft to crash two minutes after take-off.
The foreign object debris (FOD) triggered a chain of events which resulted in litigation and criminal prosecutions lasting years afterwards — as well as the entire Concorde fleet being grounded and ultimately withdrawn from service.
So, let’s explain what FOD is and why we should all be concerned about it…
What is FOD?
FOD is an important safety and quality control concept in any environment where small debris, loose objects, wildlife and even people have the potential to cause damage to equipment or injury to individuals.
The term “FOD” describes both the foreign objects themselves and any damage attributed to them. It is a particularly important concept in environments such as aviation and manufacturing.
Foreign object debris is any substance or item alien to the component, assembly or system that could cause damage. These articles could be anything from tools, parts and loose hardware to wildlife and rubbish.
In aviation, debris could create a severe hazard for aircraft, equipment and cargo, as well as personnel. In a manufacturing environment, debris could undermine quality control standards and interfere with the final product.
Foreign object damage is then any destruction or incident attributed to a foreign object that could impact the safety, functionality or performance of a product. For instance, a piece of FOD could damage delicate components, freeze control mechanisms or blow out tires at high speeds.
While EMS and the industries it supports are not directly supplying aircraft or ‘flying parts’, there is no excuse for manufacturers ignoring the risk posed by FOD. As highlighted by the Flight 4590 example, FOD can lead to a catastrophic chain of events. However, FOD can also wreak havoc on a smaller scale.
Think first about the equipment you use at home. A washing machine motor burns out due to a wire cutting left inside. A loose nut on the door catch allows the door to open with water inside. A cleaning rag blocks the inlet pipe, preventing water from getting in.
In the electronics industry, reputations are on the line, too. Serious reputational damage can occur when repeated intermittent failures are not thoroughly investigated and corrected or where poor cleanliness is ignored — be it human or the work area itself.
Along with electrostatic discharge (ESD) and cleanliness disciplines, appropriate FOD controls will assist in maintaining product quality and your reputation.
Picture this scenario…
Bob walks into the staff room. He burps and then apologises to his colleagues for his rudeness, blaming the sugar ring doughnut he has just eaten. At the workbench, Bob complains: “Who was using my workbench last night? They could have cleaned up the wire cuttings and put the tools away”.
Bob pulls the kit of parts onto his bench and starts work. With various tools and components scattered on top of the A3 assembly drawing, Bob starts to make sense of the assembly. He takes a sip from his now cold coffee and crunches on a cookie. A drop of coffee spills onto the drawing, which he wipes away with his palm.
As he removes the PCBs from their protective bag, a colleague asks for his help. Bob goes to help, placing the PCBs on his bench. His colleague asks: “Where is your ESD strap?”. Bob makes an excuse that it got trapped in a tool drawer a few days ago, and he is still waiting for a new one. On return to his workbench, Bob’s day goes from bad to worse as he reaches for the assembly drawing and his coffee tips over…
Although fictitious, this story is very close to how some companies operate today. Let’s break down the poor FOD, ESD and cleanliness disciplines in Bob’s story a little further:
- Bob failed to wash his hands before entering the work area, demonstrating a lack of cleanliness. Chemicals from food can impact solder surfaces, leave fingerprints and tarnish high-polish metal surfaces.
- The work area was not cleaned after a previous shift, indicating an absence of company discipline and a lack of a ‘clean as you go’ approach.
- There is a lack of work area preparation, as paperwork and unnecessary tools are allowed to clutter the work area.
- Wire cuttings and other debris were left in the area, with PCBs placed amongst this leading to possible debris pick up and damage.
- Food and drink are being brought into the work area, which undermines any cleanliness. If a spillage occurs, components and assemblies could also get damaged.
- There is no ESD system in place or being maintained, as indicated by Bob not having a spare wrist strap/lead available.
It is clear from this tale of woe that all is not well. There is a high risk of solder debris, wire cuttings and food or drink contamination impacting product quality and reliability.
The IPC standards set out guidance on foreign object debris, electrostatic discharge and cleanliness concerning the electronics sector. At EMS, we maintain awareness by training our staff to J-STD and IPC 610/620. As part of our 6S program, risks are also minimised through internal audits to monitor compliance and self-assessment by our managers and team leaders.
To find out more about our services and quality assurance processes, please don’t hesitate to get in touch today.