Technical Library | 2015-07-09 17:44:11.0
50,000) number of short duration (
Technical Library | 2021-08-23 01:53:13.0
After the equipment was introduced, the production capacity was increased by 20%, and the number of operators was reduced by 50%. Employees' salary expenses have been reduced by RMB 120,000 per year, and the pass-through rate has increased by 10% .
Technical Library | 2013-02-22 19:55:36.0
Productivity. Innovation. Time to market. Day to day, year over year, businesses are forced to make critical R.O.I.—related decisions that impact the future and the bottom line—some of them reactionary, some forecasted. For a growing number of electronics manufacturers, many of those decisions revolve around whether a function should be performed by an outside contractor or kept in-house. But for many companies in the RF/microwave industry, this decision is often concerned with continuing to employ an outside PCB fabricator for prototype PCBs, or to make a $10,000 to $100,000 investment in an inhouse, rapid PCB prototyping machine that may represent a key competitive advantage.
Technical Library | 2010-06-24 21:20:05.0
Cost-effective assembly of custom-designed microelectromechanical systems (MEMS) for medium-caliber fuzes is challenging. In particular, the environment must have a setback acceleration exceeding 60,000g and centripetal acceleration of 9000g/mm out of center in a 30mm#2;173 projectile. In addition, the space available is very limited. The traditional approach is to mount the MEMS chip in a package that is then soldered to the printed circuit board (PCB). However, by mounting the MEMS chip directly to the PCB using conductive adhesive, we can increase the packaging density while reducing manufacturing cost.
Technical Library | 2016-09-15 17:10:40.0
This paper describes the purpose, methodology, and results to date of thermal endurance testing performed at the company. The intent of this thermal aging testing is to establish long term reliability data for printed wiring board (PWB) materials for use in applications that require 20+ years (100,000+ hours) of operational life under different thermal conditions. Underwriters Laboratory (UL) testing only addresses unclad laminate (resin and glass) and not a fabricated PWB that undergoes many processing steps, includes copper and plated through holes, and has a complex mechanical structure. UL testing is based on a 5000 hour expected operation life of the electronic product. Therefore, there is a need to determine the dielectric breakdown / degradation of the composite printed circuit board material and mechanical structure over time and temperature for mission critical applications.
Technical Library | 2015-06-18 12:42:57.0
In the recent past, the Light Emitting Diode (LED) was hailed as the new energy efficient light source that would never have to be replaced. There were claims of 50,000+ hrs lifetime for the humble LED. That story has changed over the last few years as the number and diversity of the LED based products has increased. This is not to say that the original evidence was incorrect, but the initial enthusiastic estimates from the labs did not match the ultimate test, customers. As a result of poor quality products affecting the overall opinion of LED based products, it is critical that manufacturers can be confident in the quality of their product. In current times we want to have products certified, checked and ensure that we have the best quality. For the purposes of this paper we will look at one aspect of LED product, and this is the Lumen maintenance and estimated lifetime. The method described here does not seek to replace using high quality rating labs, but hopefully will allow the manufacturer to know with confidence that their prototype product, upon going to certification labs will be of a high enough quality that no expensive re-designs are required.
Technical Library | 2021-07-20 20:02:29.0
During the manufacturing of printed circuit boards (PCBs) for a Flight Project, it was found that a European manufacturer was building its boards to a European standard that had no requirement for copper wrap on the vias. The amount of copper wrap that was measured on coupons from the panel containing the boards of interest was less than the amount specified in IPC-6012 Rev B, Class 3. To help determine the reliability and usability of the boards, three sets of tests and a simulation were run. The test results, along with results of simulation and destructive physical analysis, are presented in this paper. The first experiment involved subjecting coupons from the panels supplied by the European manufacturer to thermal cycling. After 17 000 cycles, the test was stopped with no failures. A second set of accelerated tests involved comparing the thermal fatigue life of test samples made from FR4 and polyimide with varying amounts of copper wrap. Again, the testing did not reveal any failures. The third test involved using interconnect stress test coupons with through-hole vias and blind vias that were subjected to elevated temperatures to accelerate fatigue failures. While there were failures, as expected, the failures were at barrel cracks. In addition to the experiments, this paper also discusses the results of finite-element analysis using simulation software that was used to model plated-through holes under thermal stress using a steady-state analysis, also showing the main failure mode was barrel cracking. The tests show that although copper wrap was sought as a better alternative to butt joints between barrel plating and copper foil layers, manufacturability remains challenging and attempts to meet the requirements often result in features that reduce the reliability of the boards. Experimental and simulation work discussed in this paper indicate that the standard requirements for copper wrap are not contributing to the overall board reliability, although it should be added that a design with a butt joint is going to be a higher risk than a reduced copper wrap design. The study further shows that procurement requirements for wrap plating thickness from Class 3 to Class 2 would pose little risk to reliability (minimum 5 μm/0.197 mil for all via types).Experimental results corroborated by modeling indicate that the stress maxima are internal to the barrels rather than at the wrap location. In fact, the existence of Cu wrap was determined to have no appreciable effect on reliability.
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