You can probably imagine some of the things we’ve seen from the hundreds of customers we serve over the years. But I think the thing that gets the most violent reaction is when I have to tell someone the parts they sent are pulls when they believed them to be new.

It amazes me that someone can examine a part to determine if it is counterfeit but they can’t see the signs of a part that’s been pulled off a board. Of course it fascinates them when I tell them we can’t tell if a part is counterfeit but can tell if it’s a pull.

Admittedly, a carefully pulled and cleaned part is virtually impossible to identify. But when hundreds or thousands of parts are being pulled to fill an order, then little clues are usually left behind. These little clues can save your company countless failures and the good faith of your customers. We keep a stereo microscope in receiving area so we can easily check suspicious lots.

Probably the most overlooked clue is when components come in the wrong or mixed brands of tubes. This should set off every alarm you have!! The last I asked around component manufacturers did not share tubes with each other and they usually have a single source of tubes. Parts in non-factory tubes have obviously been handled. This in itself is not necessarily bad, but it’s a warning sign to do a check the condition of the parts. The second is very similar, that a batch of parts comes in tubes from assorted sources.

A legitimate distributor, added value facility or CM will have enough of a single brand to do even larger quantities. But even if the tube brands are mixed, identifying if the parts are really new or pulls isn’t usually difficult.

When parts are pulled off a board, the solder must be heated enough to ‘flow’ properly and leave a smooth finish. This can take a minute or two with the right equipment, and since time is money, part pullers are usually in a hurry.

In any batch of pulls, a number of them will usually have oversized lumps of solder on them. These normally occur along the top or edges of the contact surface and are caused when the solder is not hot enough to flow properly. Realizing solder paste on a PCB is only about 0.006" thick, the lumps are rarely large – but they are big enough to see if you’re looking for them.

New parts from the factory generally have a smooth even finish, but pulls often display a sudden change along the foot pad where it contacts the solder. It can be extra solder that didn’t come off, scratches from probes and if the parts were man handled, the leads can be bent or a variety of things. A good rule of thumb – If they’re new parts they’ll all look the same and if they don’t – there’s a good chance you’ve got pulls.

Pulls are also likely to have some type of debris left on the contact surface or lead edges. It could be anything from dust contaminating the solder to small bits of other foreign matter mixed in.

The bottom of the actual body is sometimes scratched or gouged. In a perfect world it would never happen, but impatient part pullers sometimes try to speed the process up and lift the part up with a probe. This can leave marks that are almost invisible to deep gouges along the underside of the body, but since the bottom is almost never inspected, it is often overlooked,

If you know you’re buying pulls that’s one thing; but if you think you’re buying new components, taking these basic steps can help you avoid disaster.

At Advanced Component Taping, we routinely track whether components are received directly from our customer or another source. We also provide receiving inspection for some of our customers and we have extensive documentation and procedures in place to catch wrong shipments and pulls. Best of all, we can be part of YOUR TEAM!!!

Find out what we can do to make your life easier è moreinfo@actaping.com