By Ron Iscoff, Editor
X-ray inspection to detect anomalies in packaging ICs offers a powerful, nondestructive method of finding flaws. Suppliers of x-ray inspection systems, who now number about a dozen, have been paying increasing attention to targeting their wares to the PWB and semiconductor packaging industries over the past few years. As x-ray moves out of the failure analysis lab, system suppliers want users to consider their products an essential addition to the inspection tool menu.
We'll review a few of the leading systems and suppliers here, mostly in their own words (and, of course, alphabetically): Agilent Technologies, formerly the test equipment arm of Hewlett-Packard, supplies a top-of-the-line, full-featured (and expensive) unit, the Agilent 5DX Series 3. The system employs cross-sectional x-ray imaging (laminography) for detecting solder joint defects on single- and double-sided PWBAs with almost any type of SMT or PTH component. Features include 99 percent fault coverage of PWBAs with limited test access. Fast test setup requires no fixturing and test development can be accomplished in less than a week. Dage Precision Industries promotes the robust construction, innovative software and limited automatic recognition capabilities of its systems (Figure 1). "These features make the Dage Systems unique," according to Hal Hendrickson, global marketing manager.
Through Dage's point-and-click software, an operator can easily inspect the sample. Without the use of joysticks or laser pointers, any portion of a sample can be identified, magnified, rotated and inspected. Faxitron provides several units, including the CS-100 real time unit. The CS-100 is designed to inspect SMT assemblies, ICs and PWBs. The unit, and its counterpart the CS-90, employs a microfocus source with a fixed spot size for high-resolution imaging. Faxitron says this unit is ideal for looking at hidden features such as BGA and flip-chip attachments, wire sweep, die attach, encapsulated assemblies and inner-layer registration. FeinFocus recently introduced the FOX-160.25 (Figure 2), along with other versions of "The Fox." The company calls it "the industry's first nanofocus x-ray inspection system offering sub-micron defect detection. The Fox combines x-ray technology with advanced optics, which makes it ideal for real-time inspection of BGA, µBGA, CSP, flip chip, COB, bond wires, wedge bonds vias and other applications where precise measurement is needed. GenRad Inc., through its acquisition of Nicolet Imaging Systems about a year ago, entered the x-ray inspection equipment business. One of GenRad's newest systems, the GR-X130 introduced in July, uses a 5µ spot and a powerful 130 kV x-ray source. The unit features a 5-axis control that enables users to acquire any view or compound angle of dense heat-conducting materials, noneutectic solder balls, flip-chip assemblies and ultrafine-pitch solder joints. Glenbrook Technologies recently announced a newly developed, large- capacity inspection system (Figure 3) known as the "oversized Jewel box 90-C." According to Glenbrook, the system eases x-ray inspection of larger assembled PWBs up to 18" x 24" with its high-voltage, 90kV energy source.
The company has also introduced variable angle viewing for its RTX-113HV inspection system. The HV model employs a higher-voltage x-ray source, needed for PWBs with dense, leading-edge packaging, including CSPs. Variable angle viewing is achieved by rotating the x-ray source. Phoenix X-Ray Systems + Services Inc. has introduced the "pcba analyzer," a high-resolution x-ray system for inspection and failure analysis (Figure 4). Phoenix says its OVHM (oblique view at highest magnification) maintains 1000x geometric magnification through 45 degree oblique inspection. The company claims it's the only 2D system to attain this magnification in oblique views. This is accomplished by moving the image intensifier. Photon Dynamics (formerly CR Tech-nologies) offers a wide selection of x-ray sources. These include low-maintenance, sealed microfocus tubes through high-resolution, demountable tubes with replaceable filaments and high geometric magnification. The x-ray series is offered with a variety of 4- and 5-axis sample manipulators and x-y travel up to 18" x 24" for samples weighing up to five pounds. Viscom's VXR 8016 offers "True Auto-Focus Technology" (TAF), which represents "a significant improvement in x-ray inspection technology," according to Viscom. TAF ensures optimum image quality under all circumstances, instead of resorting to stored factory curves, as in the past.
VJ Electronix supplies the VJ-2000 DIG, introduced in January (Figure 5). It features a flat panel detector for high quantum efficiency, large imaging areas, moderate-to-high spatial resolution and distortion-free images. The digital FPDd provides over 65,000 shades of gray, compared to the 16 to 32 shades provided by analog-based detectors. X-Tek, a British firm with a substantial U.S. presence, provides a range of systems with an integral x-ray source designed and manufactured in-house (Figure 6). All elements of the source are housed in one unit, which has driven down the size, cost and weight. The company's "iXS" software enables the system to be controlled manually or as an advanced programmable, semi-automatic inspection tool. X-Tek claims to have the highest level of magnification in the microfocus x-ray field. For detailed specs on leading systems from most manufacturers, see the accompanying table. |
Copyright © 2001