Links > Articles

News - Cool Stuff - Articles

 

30 Years of Bringing Bad News, One Board at a Time

By Robert Boguski, President, Datest

Failure, contrary to what many may think, can be an option. Failure can even teach a great deal, especially when it results from a malfunctioning process. Datest (www.datest.com) has been in the business of testing and inspecting printed-circuit-board assemblies (PCBAs) for 30 years, learning from failures by means of in-circuit-test (ICT) processes and helping customers to correct whatever might be causing those PCBA failures. 

For Datest customers, circuit-board failures mean missed shipments and lost dollars. Board failures that are not detected in a timely manner can ruin the reputation of a contract manufacturer (CM) or supplier of electronic manufacturing services (EMS). But Datest can help. The firm, based in Fremont, CA, has been an ISO9001- and AS9100-certified provider of advanced, integrated PCBA testing, inspection, and engineering services to the CM/EMS and OEM communities since 1984. In those 30 years, Datest has augmented Agilent/Keysight, Teradyne, and GenRad ICT with SPEA flying probe testing, Goepel and Asset boundary scan testing, Agilent 5DX automatic x-ray inspection, and failure analysis using the Nordson DAGE XD7600NT500 Ruby X-Ray Inspection System with X-Plane Technology. Engineering is followed by testing, either at Datest's facility or on-site at a customer's designated contract manufacturer. Every customer has different preferences, and Datest respects and works within each set.

It is important to provide real value as part of testing. When a circuit board fails and is brought to Datest, it is evaluated and returned to a customer, not just with a simple description but with fully diagnosed faults to the component level. Datest may even rework a board, removing and reballing suspect BGAs as warranted. If given 100 nonworking boards to evaluate, the firm will try to return as close to 100 good boards as possible. 

In addition, much can be learned by listening to customers, who have budgets and expectations, and the two may not always coincide. A customer may also not be aware of full test capabilities for evaluating PCBAs. Because of this, personnel will listen to a customer's needs and then try to steer them towards the most cost-effective solution for evaluating their PCBAs. The term "Integrated Testing Solutions" is not just a slogan but a way of life at Datest, where the company has focused on relentlessly delivering value to its customers. 

For example, a customer feeling strongly about implementing ICT on one circuit board may not realize that the board was not ideally suited for ICT. A better solution, for example, might be a combination of flying probe and automated x-ray inspection, which can result in improved cost and throughput for the board than trying to implement an ICT approach. A customer may bring in a board with little background information, only that it failed. Datest personnel will ask for more specific information, even about the suspected root cause of the board failure, in order to discover a solution for that board. 

Datest serves a wide range of industries, including automotive, biotechnology, consumer, data encryption and security, contract manufacturing, environmental controls and technology, industrial, medical, military/aerospace, product design/development, solar/photovoltaic, and telecommunications. The company supports these industries through a comprehensive repertoire of systems and technologies, including ICT from such suppliers as Agilent Technologies, GenRad, Teradyne, and Agilent Technologies, with their Agilent 5DX AXI inspection services, benchtop boundary scan, and functional testing, augmented with SPEA flying probe testing. The company has established numerous close partnerships with key complementary service and equipment providers. For example, Datest is a Center of Expertise (COE) for Goepel Electronic (www.goepel.com) as well as the West Coast equipment demonstration site for SPEA (www.spea.com) flying probe test systems. 

Datest is the first test services company in the US to fully integrate a model 4060 double-side flying probe tester from SPEA with the latest Goepel boundary scan tools. This integration provides crucial benefits, such as increased digital test and fault coverage as well as significant time savings using automatic diagnostics. The combination of advanced tools and extensive test experience translates into superior value-added services for customers. 


Failure Analysis

Support services are critical to today's electronics industry and Datest works to provide comprehensive support capabilities, updated as needed. Time is an important part of any solution, so when process engineers arrive at with a suspect circuit board, every effort is made to provide them with clarity, direction, and the beginning of a resolution to their process problem, through up-to-date testing services and expertise. 

Our personnel are well aware of the growing importance of long-term reliability for manufactured electronic products, and that some boards that pass initial electrical testing have no assurance of long-term reliability in the field. Our testers have become increasingly aware that any board inspection and analysis must look for these "hidden" failure mechanisms that may not be obvious during initial testing but that may contribute to degrading a board's long-term reliability. 

Datest offers a variety of services, helping with the troubleshooting, repair, and retesting of failed boards; with BGA removal and replacement; with computer-aided-design (CAD) and Gerber computer file conversion services; mechanical design for testability (DFT) analysis, electrical DFT analysis, test strategy consultation and implementation, test sanity checking, design for manufacturability (DFM) analysis, lot tracking and statistical reporting, and mixed OEM/EMS provider engagement. The company also provides third-party dispute resolution, for example, to adjudicate a disagreement between an OEM and CM or EMS supplier. 

Bonepile Rehabilitation

Circuit boards that fail under warranty or are considered unrepairable by an OEM are typically written off and placed in a "bonepile." These defective PCBAs represent lost revenue, and a challenge to test and repair. OEMs often invest time and resources in troubleshooting these PCBAs, with little return on investment. As an alternative, Datest offers test resources and expertise that can represent a more practical approach to an OEM. By helping to rehabilitate the bonepile, this helps to recover revenues for customers. 

The concept of rehabilitating the bonepile is fairly straightforward: customers bring their data, available documentation, and previously written-off failures. Datest then uses its test engineering resources and measurement platforms to bring these failed boards "back to life." The firm makes full use of its suite of integrated testing resources to troubleshoot, rework, and restore PCBAs to operational status per the requirements of a customer's functional or system test, or even in the field under operating conditions. This involves directly reworking the boards or showing customers where to rework them if a customer prefers to make these modifications within their own facility. Communications is a key to achieving success in this "rehabilitation" process, and Datest works closely with a customer to communicate what is defined as a "good" board after it has been reworked. The rehabilitation service is offered at a fraction of the original manufactured cost and is suitable for reverse logistics, warranty repair, and returns management programs.

The same hardware and software resources used for production board testing are also used at Datest to aid troubleshooting, fault diagnosis, board repair, and board recovery. For these purposes, testing is often performed with the flying probe system or using x-ray inspection or boundary-scan/JTAG testing. In each case, the goal is to develop an efficient test solution that is both cost-effective and delivers significant value (i.e., has a high recovery rate) at zero-risk to customers. By analyzing the failures and using its full range of testing solutions platforms and engineering know-how, it is possible to rehabilitate many of the bad boards, restore "lost" revenue and contribute to a greener world. This is an economical and intuitive answer to a perennial issue that delivers significant monetary and environmental benefits in a world where diminished resources have become a fact of life. 

It's important to understand the importance of adapting to industry needs and providing the most comprehensive value-added services possible. What started as a small EMS has grown into a thriving, multifaceted services provider, leveraging the latest measurement capabilities to help customers. The company uses its technologies and experience to present cost-effective, environmentally friendly solutions to the challenge of failure analysis. Failure is indeed an option, if it is possible to learn from it and find practical solutions.