-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueBox Build
One trend is to add box build and final assembly to your product offering. In this issue, we explore the opportunities and risks of adding system assembly to your service portfolio.
IPC APEX EXPO 2024 Pre-show
This month’s issue devotes its pages to a comprehensive preview of the IPC APEX EXPO 2024 event. Whether your role is technical or business, if you're new-to-the-industry or seasoned veteran, you'll find value throughout this program.
Boost Your Sales
Every part of your business can be evaluated as a process, including your sales funnel. Optimizing your selling process requires a coordinated effort between marketing and sales. In this issue, industry experts in marketing and sales offer their best advice on how to boost your sales efforts.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
Web-based ATE Adapts to Test Future Technology
December 31, 1969 |Estimated reading time: 6 minutes
Easy access to test data and a broad range of tools for test program development are employed via Web-based technology.
Dave Rolince
Electronics manufacturing is changing. Printed circuit board (PCB) inspection and test strategies are evolving to reflect the new needs of the manufacturing environment. What are some of the device and board packaging and performance trends impacting board inspection and test strategies?
- The ascendance of hand-held products and the growing demand for denser circuit packaging.
- More functions on a single board, such as RF next to processors found on cell phone handsets.
- Emergence of system-on-a-chip (SOC) packaging that will result in more function per square centimeter of board.
- Software content on boards continues to increase, usually encapsulated in ISP and nonvolatile (flash) memory that must be programmed during the manufacturing process.
Even as inspection and process test strategies become more cost-effective and productive, functional test (FT) will remain as the final "quality gate" to determine if the newly manufactured board will go onto the next level of assembly. FT has not yielded to commercial automated test equipment (ATE)-like in-circuit test (ICT) because each manufacturer builds boards with unique (function-oriented) test requirements. This has resulted in a proliferation of customized test sets that are expensive to design and build in one-off quantities, difficult to upgrade when product requirements change, and rarely provide thorough diagnostics in dealing with failed boards.
The emergence of open architectures employing industry standards such as VXI, LabWindows* and Windows NT means that commercially available ATE can address in-house design. The end result of open-architecture hardware and software is higher throughput, a more rigorous production environment, structured programming paradigms and documentation control - all aimed at reducing FT cost and cycle time.
Test program set (TPS) development, documentation, debug and execution benefit from both open architecture and Web technologies to integrate development processes and tools from multiple sources. The result is an open, easily reconfigurable TPS operating environment that combines flexibility with a process-oriented framework.
Since its introduction, Windows has revolutionized the way engineers think about and implement programming on ATE. Hundreds of commercial tools have been developed that leverage Windows technology. Graphical programming tools enable engineers to do in minutes what used to take hours of programming in C. In spite of the productivity gains graphics-based tools offer, the challenge of integrating the output of these tools into an organized, documented process, where each step can be traced to supporting development and documentation sources, remains. One of the most promising solutions for integration exists in the combination of Windows and Web-based technologies.
An example of a modular, flexible ATE operating environment that runs under Windows 95, 98 and NT is shown in Figure 1. Test processes take the form of a Windows "tree" structure that supports hierarchy and sequence flow. A typical process tree contains a series of nodes that may or may not be hierarchical. Each end node on a tree is called a leaf. The leaf is where the operating environment communicates with other programs and processes. The communication is achieved through component object model (COM)-interfaced objects called leaflets. Leaflets enable communication between the operating environment and other programs by passing the values of mutually recognizable "properties" back and forth. The operating environment supports inheritance so that properties can be passed down through the hierarchy of a tree`s parent branch. In this way, data can be captured, stored and managed within a project.
The principal user interface is a Web browser that displays the status of each selected end node in a process and acts as the entry point for user input. The use of the Web supports static and dynamic text, graphics and video displays.
TPS Documentation Simplification
In a documentation tree, all relevant test program documents can be catalogued and referenced. Using universal resource locator (URL) addresses (Figure 2), documents can be accessed and displayed locally from any network to which the operating environment has access - from a file server on the local network to a geographically remote location accessible over the Internet. This offers the ability to provide broad access to important documentation sources and, at the same time, maintain strict configuration control that is critical to eliminating the ubiquitous problems associated with using the wrong information to generate a test program.
Web browser technology also has the advantage of being able to display hyperlinked text markup language (HTML) documents as well as active graphics such as video. For example, an execution step in a production test program could navigate to an URL that runs a video clip to illustrate how to attach a fixture to the tester, or how to execute a probing sequence to isolate a failure on the UUT. This can be significantly more effective than describing a procedure in text or in a static diagram.
Test Strategy Implementation
Once a test strategy has been decided upon, a test developer will define and lay out the test steps to implement the strategy. This typically takes the form of a flow diagram that is identical in structure to the Windows Explorer tree used in the operation environment. Once the details of the flow have been defined, it can be saved and archived for reuse in a test program employing the same or similar flow. Existing process tree architectures can be imported into a test project by simply copying the archived process into the new project. This can save significant development time and provide a means for standardizing test processes at a high level.
Test Design and Execution
One of the most time-consuming efforts in test program integration is generating the high-level executive process that sequences and manages the application of each coded test module. While integrating modules that use the same programming language helps reduce the effort, this is not always feasible. Integrated UUT test solutions frequently employ a variety of tools from different vendors or a combination of commercial products and custom C/C++ code. This can result in complex test programs that are difficult to create and nearly impossible to reuse.
Through the use of leaflets, the open-architecture operating environment simplifies the process of test module access and control. A leaflet library enables communication with application development environments (ADE) such as LabVIEW and LabWindows/CVI, and HP VEE** (Figure 3). These ADEs support the Microsoft COM interface standard, which is the foundation of leaflet technology.
Over the course of test program integration and debug, test program execution flow frequently needs to be modified or resequenced. The Windows environment simplifies this task by supporting cut/copy/paste and drag-and-drop capabilities. Any node modified by these actions automatically carries its property assignments.
Conclusion
Graphical test process generation, and test program code and documentation using the Web, are essential components to a cost-effective TPS development solution.
An open-architecture operating environment that enables reconfiguration and reuse of test resources provides flexibility. This test flexibility accommodates the changing board packaging and performance trends of tomorrow. By employing familiar Web technology and industry standard COM interfaces, easy access is provided to test data and to a broad range of tools for test program development.
* National Instruments.
** Hewlett-Packard.
DAVE ROLINCE may be contacted at Teradyne Inc., 600 Riverpark Drive, North Reading, MA 01864; (978) 370-2700; Web site: www.teradyne.com.
Figure 1. User interface showing the Windows Explorer tree control (left) and Web browser (right).
Figure 2. Documents and other files are referenced by their URLs.
Figure 3. COM interface programs called leaflets are selectable in the property sheet of a node.