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BEST offers a variety of analytical testing services to help you spot and trend defects, process or part changes.
Visual, Endoscopic, and X-RAY inspection, as well as dye and pry inspection services are offered by BEST in order to help you diagnose and troubleshoot and sort out a variety of defects. Our highly trained staff is able to assist you in analyzing
specific defects.
Visual "Referee" Inspection
BEST can be your "referee" resource when clarification is required regarding
a PCB or wire harness acceptance standard interpretation. Our Master
Instructors, who are military trained and have been Master Instructors for the IPC A 610 courses for many years can provide a "third set of eyes" when an issue
arises in the PCB assembly process. We can provide a detailed report for
refereeing purposes. When you need an outside expert opinion, or when you
need to determine the existence of a PCB assembly process problem.
Endoscopic Inspection
 BEST uses a dedicated BGA/CSP
endoscopic inspection tool in order to see underneath SMT parts. Defects like opens and voids are some times difficult to discern-even with XRAY equipment. That is why BEST has the latest in inspection tools available for its customers including a high-powered
endoscope system that allows BEST technicians to actually see underneath BGAs, CSPs and even flip chips.
Several characteristics of the solder ball can be determined with this tool. The actual standoff height, as well as degree of warpage, can be measured. Capture software allows for both absolute and relative measurements. This allows BEST to help you set up QC measurements for real-time references for the boards being inspected.
Several defects can be measured and recorded via .jpeg or .mpeg images. For example, solder joint cracks in connections inside, outside or under the component body can be seen. Micro-cracking of the component body (popcorn effect) without component removal can also be seen using this tool. In addition flux residue trapped under the component after soldering can be documented.
X-RAY Inspection
X-ray inspection has become a generally accepted method to control the quality of board assemblies and to analyze defects of hidden solder joints. It is key to efficient implementation and monitoring of the reflow process for BGA, CSP and flip-chips. For optimum use of this tool both the right equipment along with a properly-trained staff, which can properly interpret the results and their relationship to process and component variables, should be used.
Skilled XRAY technicians like those at BEST make a difference in being able to help you detect process problems
or screen for known defects. For instance, some defects such as bridges can be "seen" directly while others can only be detected by their signatures. The correspondence of the signatures to the various defects is known from experience, but can be understood from simple geometrical considerations. For example, if a single BGA solder joint appears brighter than its neighbors, it is obviously not as thick and, hence, must be open (not properly soldered).
BEST skilled X-ray technicians can help you screen for defective products based
upon yours or BEST's developed acceptance criteria for the given defect. X-ray Inspection Services
Dye and Pry
The "dye and pry" technique, which relies on a liquid dye that penetrates into
existing micro cracks or under open solder balls is a destructive test method
for the revealing of defects on the solder ball to pad interface (see figure
below). After letting the dye dry, the BGA is "pryed" off its PCB and the
solder balls are inspected for the presence of the dye which reveals the
location of the interfacial connection problem area. Dye & Pry Services
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