QualMark's patented OVS (OmniAxial Vibration System) tables used in their HALT and HASS chambers excite every part of a product, down to the component level, at its resonant frequency. This requires vibration in all three axes as well as the rotation around those axes, simultaneously, across a wide frequency range. At the same time, and within the same chamber, thermal tests are undertaken. The chamber's patented Typhoon air-handling technology drives products from ambient to the appropriate stress temperature quickly using less electricity and liquid nitrogen.
"If you looked at a pie-chart and it showed all possible defects, you'd have a certain percentage showing up at extreme high and low temperatures, during thermal cycling, under vibration in all axes, and during combined vibration and thermal cycling," said Charlie Bates, VP of program development. "To cover all the bases you have to test both vibe' and temp simultaneously, because studies have shown that you can otherwise miss 25-30% of the defects."
In addition, thorough HALT and HASS testing requires broad frequency excitation, far beyond what a product might see in the end use environment, to ensure that weak links are quickly exposed.
"Our new xLF vibration system is unique in shifting the energy in the frequency domain down to the zero to 5,000 Hz range. With 50% of the energy below 2,000 Hz and 50% above, we simulate the resident frequencies in various types of electronic hardware, including PCBs," continued Bates. "This quickly brings out potential real-world problems such as weak solder joints and incomplete surface-mount connections."
QualMark authorized test centers have conducted over 4,000 HALT and HASS tests since 1991, employing services such as customer directed testing, production screening, production HASA (Highly Accelerated Stress Audits) and on-site testing.
MIDLAND, MI — The Dow Chemical Co. is raising prices in North America for a wide selection of its epoxy resin products. Expoy resins are a basic component of laminates used in printed wiring boards.
Effective July 1, 2006, or as contract terms allow, Dow will increase off-list prices for liquid, solid, solid solution and brominated epoxy resins by six to eight cents per pound.
Valor Computerized Systems has announced a full Pb-free environment control solution covering market-leading machine vendors, regardless of brand and model generation. The TraceXpert operations monitoring and control solution for EMS companies delivers machine vendor neutrality for line-monitoring, real-time materials management, optimized assembly line performance and component traceability.
With the July deadline for the RoHS Directive almost here, electronics manufacturers are focused on sourcing Pb-free components through improved and revised production and inspection processes for compliance. TraceXpert assists that process by blocking uncertified AVL components from entering the assembly cycle, by preventing unauthorized operators from running the Pb-free process, by ensuring proper control of moisture-sensitive devices and preventing inadvertent tampering with process parameters. In addition, exact traceability capabilities allow manufacturers to produce device compliance history records, and provide customers and authorities with evidence to support their Pb-free process certification.
LPKF ProLegend is a fast, easy-to-use system that creates professional legend print on PCB prototypes.
Environmentally friendly, does not require screen printing and comes with all the necessary tools and consumables included. Requires very little training.
Allows legend printing to be an easy in-house process, increasing security and eliminating production delays. Legend print can be added to a circuit board instantly through a simple process. Before applying the legend print a solder mask can be applied with the LPKF ProMask system, allowing instant turnaround.
Uni-form epoxy performs are now available in M5-82, a linear epoxy system that remains flexible under temperature changes. The post-cure flexibility of M5-82 improves adhesion to component materials with dissimilar coefficients of thermal expansion. The epoxy was developed for under-the-hood automotive applications and other environments that require seal integrity under adverse temperature conditions.
Are one-part epoxy resins that are solid at room temperature. When heated, they melt and cure, forming a consistent seal that protects components from dust, moisture, oil, flux, solvents, conformal coatings and other contaminants. Close tolerances on preform dimensions, consistent pre-mixed ratios of resin to catalyst and consistent viscosity from beginning to end of batch ensure uniform, high-quality results. Are available in multiple configurations, with outside diameters from .035" to .720". Preforms can be dispensed as rapidly as 200 to 600 parts/min. with little or no operator training. Reportedly eliminate pot-life concerns and costly cleanup procedures.
Anritsu Co. has reduced the time to develop communications test solutions 4 to 6 weeks, eliminating a PCB re-spin by modeling thermal management at the board and systems level during the early design process. In the past, Anritsu engineers were not able to address thermal issues at the board level until the prototype stage when physical testing was performed. “Now we use Flomerics’ FLO/PCB software to optimize component placement before prototyping,” said Teresa Whiting, Mechanical Design Engineer for Anritsu. “The result is that no additional prototypes have been required for thermal reasons since this method has been used.”
Anritsu has modeled the thermal performance of its products for a number of years but in the past thermal simulation was not fast enough to keep up with the rapid pace at which the company designs PCBs. So, thermal design had to wait until the prototype was built and mechanical engineers created thermal photographs and measured temperatures of the boards. At the same time engineers also modeled the product at the systems level with Flomerics’ Flotherm software. Typically, the simulation identified hot spots or other problems on boards. Engineers then went back and repositioned components, rerouted traces, and built a new prototype. The extra board spin added directly to the time required to bring the product to market.
About a year ago, Anritsu became one of the first users of FLO/PCB, a software package that makes it practical to perform thermal modeling during PCB design. Electronic engineers now provide mechanical engineers with placement information and data sheets on key components of the PCB. The mechanical engineers then quickly model the board and simulate its performance under standard airflow and temperature conditions. They often reposition components at this stage or add a heat sink and, when they are satisfied, then plug the FLO/PCB model into a Flotherm system model, which usually already exists, and determine the thermal performance of the board under actual conditions.
“Modeling PCBs during the design stage makes it possible to get the board design right from a thermal standpoint every time,” Whiting said. “This has eliminated the need for a second thermal prototype and saved us 4 to 6 weeks in bringing every product to market. In a typical example, FLO/PCB showed us that junction temperatures were too high on a couple of voltage regulators. The system level simulation showed us exactly where we needed to reposition the boards to get enough airflow. We provided that information back to the EEs designing the board, so they were able to get the layout right the first time.”