Most in the electronic manufacturing services industry are acutely aware of the growing problem of counterfeit and substandard electronic components within the supply chain, as well as the headaches that they cause.
Although industry and governments are working diligently in addressing counterfeit abatement, you may already have one of the most useful tools in combating phony parts in place right on your production floor.
Some would suggest that you need not concern yourself with counterfeits if you simply follow this best practice: Buy directly from manufacturers and authorized distributors only. But for many, the day-to-day realities of procurement demand that they enter the open market. It is also worth noting that franchise distributors are not immune to the problem of counterfeiting, as they too rely on the open market at times to meet demand. Organizations such as the Buena Park, California-based Independent Distributors of Electronics Association (IDEA) are addressing the problem by developing an inspection protocol aimed at intercepting counterfeit and substandard parts before they reach your receiving department, and many of the most reputable distributors are adopting the IDEA’s standard, IDEA-STD-1010-A--”Acceptability of electronic components distributed in the open market.” Still others, such as NexGen Digital Inc., located in Irvine, California, are going beyond visual inspection by incorporating advanced devices such as X-ray inspection systems, X-ray fluorescence, and decapsulation systems to verify the authenticity of manufacture prior to resale distribution.
Since the advent of the ball grid array (BGA) package, many original equipment manufacturers and contract manufacturers have incorporated X-ray technology as part of a quality manufacturing process. Your existing X-ray system can be a valuable tool in assessing the authenticity and quality of your incoming parts orders. X-ray is unique in its ability to look inside parts without destroying them, and in fact, without even removing them from their antistatic packaging, trays, or tubes.
Utilizing your existing X-ray inspection system as part of your receiving process may be prudent when sourcing components on the open market, particularly if the distributors with whom you are working have yet to adopt X-ray inspection as part of their quality control process. With a little training, your receiving team will quickly develop the skills and knowledge necessary to check incoming parts not only for authenticity, but also for important quality indicators.
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An effective X-ray inspection protocol includes:
• Overview inspection (top-down view) that looks for:
-- Die presence/absence
-- Die dimensions (requires image processing measurement tools)
-- Die attach material presence/absence
-- Leads, paddle, and bond wire layout
-- Bent or deformed leads
• Magnified views that inspect for:
-- Die attach cracks and voids
-- Molding cracks and voids (using low kV X-ray)
-- Proper ball and wedge bond attachment (requires high magnification and resolution)
• Side and oblique views that reveal:
-- Die thickness (requires image processing measurement tools)
-- Bond wire geometry
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Although these two samples have identical exterior markings, X-ray inspection reveals distinctly different die, lead frame, and bond wire connections. |
Provided that your system features a large enough field of view, it is best to start with the overview, which will quickly expose gross counterfeits in which the die or other critical features may be absent. If your image processor allows, you may wish to apply measurements to features such as the die or paddle, which can be especially useful when a known good part is available for comparison. Archiving the resulting images can also build a powerful resource for future comparisons.
Outright counterfeits, of course, are not the only threat. Substantial numbers of refurbished components are finding their way back into the supply chain, posing as new, authentic parts, or re-marked to impersonate higher-cost components. Still others may reach your dock as scavenged rejects or as the product of unauthorized (i.e., “third shift”) production runs.
X-ray inspection exposes a number of quality indicators that can aid in preventing substandard parts from corrupting your products. An overview image, as described earlier, can reveal bent leads, cracks, or voids in the component body, as well as die attach voids and cracking. Magnified and angled or oblique views may show defects in bond wire quality-- such as bond wires that are broken or bent--demonstrate inconsistent loop height, or are poorly attached.
Particular attention should be paid to cracks or voids. Such features within the die attach material can be indicative of previous thermal cycling and thus suggest the possibility that the part has been refurbished. Although components with substantial die attach defects may pass functional tests, they will likely suffer from limited reliability. Additionally, components featuring voids within the plastic body or within the die attach material are often rejected by the manufacturer. These parts can find their way into the supply chain by way of unscrupulous employees or scavengers. It should be noted that authenticating components through decapsulation does not alleviate concerns regarding quality issues such as cracks and voids because faults of this type can only be revealed under X-ray inspection. Because outright counterfeits are not the only type of substandard parts corrupting the supply chain, it is also important that issues of quality as well as authenticity are addressed. X-ray inspection has the ability to aid in confirming authenticity, and it also has distinct advantages in revealing characteristics of otherwise misrepresented parts.
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Recently a San Diego, California-based distributor contacted FocalSpot Inc., a Southern California-based provider of X-ray inspection equipment, for assistance in restoring customer confidence. The customer suspected it had received an order containing potentially counterfeit components because it noted slight external visual discrepancies between its existing stock and new parts.
In this case, both the distributor and the customer provided samples of the same part. Initial low-magnification overview X-ray images of each sample were produced using a FocalSpot Verifier HR X-ray system. The captured images were compared and revealed no discernable differences.
Next, a more detailed view was generated at higher magnification. Again the images were compared and detailed characteristics of the components were reviewed. Again the samples appeared to be consistent with one another.
The inspection took only seconds to complete, but ultimately resulted in confidence between the vendor and end-user being restored. The transaction was salvaged, and both the distributor’s and the contract manufacturer’s interests were satisfied; for the contract manufacturer, valuable time was saved by not having to find an alternative source for the required product, perhaps at a higher price.
Small-cabinet, manual X-ray systems are ideal for inspection of counterfeit components. If such a system prevents a single incident of counterfeit parts from reaching your production floor, it is well worth the investment. Consider dedicating such a system to receiving, and it can also serve as a valuable backup in the event that your production system is down.
Until your suppliers widely adopt X-ray inspection as part of their quality processes, consider utilizing your existing X-ray system in your receiving processes. Doing so will provide an added benefit to your customers and increase your competitive advantage.
Wells is the inside sales and support manager at FocalSpot Inc. located in San Diego, California, a provider of affordable high-quality BGA/SMT inspection and rework solutions to the electronics manufacturing industry worldwide.
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