Technical Library | 2019-07-10 23:36:14.0
Pockets of gas, or voids, trapped in the solder interface between discrete power management devices and circuit assemblies are, unfortunately, excellent insulators, or barriers to thermal conductivity. This resistance to heat flow reduces the electrical efficiency of these devices, reducing battery life and expected functional life time of electronic assemblies. There is also a corresponding increase in current density (as the area for current conduction is reduced) that generates additional heat, further leading to performance degradation.
Technical Library | 2023-12-18 20:41:20.0
This review of inert atmosphere for the electronics assembly processes will look at the benefits and attempt to close the gap on some of the misconceptions of using inert gases for electronics assembly. We will look at the reasons for using nitrogen and the cost benefits that come with the use of this inert atmosphere gas. As part of this review we will be explain the needs assessment and when you should use an inert atmosphere for your assembly process. Case studies will be provided to demonstrate the benefits of an inert atmosphere in the electronics assembly process area.
Technical Library | 2015-03-26 19:16:03.0
Nickel-palladium-gold-finished terminals are susceptible to creep corrosion. Excessive creep corrosion can result in device failure due to insulation resistance loss between adjacent terminals. The mixed flowing gas test has been demonstrated to produce creep corrosion on parts with nickel-palladium-gold finished terminals. Conformal coats are often used to protect printed wiring assemblies from failure due to moisture and corrosion. However, coating may not be sufficient to protect lead terminations from failure.In this study, acrylic, silicone, urethane, parylene, and atomic layer deposit (ALD) coatings were examined for their effectiveness at preventing corrosion of nickel-palladium-gold-finished terminals.
Technical Library | 2015-01-22 17:32:27.0
Temperature requirements for ceramic capacitors have increased significantly with recent advances in deep-well drilling technology. Increasing demand for oil and natural gas has driven the technology to deeper and deeper deposits resulting in extreme temperature environments up to 200°C and above. A novel capacitor solution utilizing temperature-stable base-metal electrode capacitors in a molded and leaded package addresses the growing market high temperature demands of (1) capacitance stability, (2) long service life, and (3) mechanical durability. A range of high temperature C0G capacitors capable of meeting this 200°C and above high temperature environment has been developed. This paper will review the electrical, reliability, and mechanical performance of this new capacitor solution
Technical Library | 2017-04-20 19:16:17.0
IST AG thin film mass flow sensors offer solutions for a wide variety of flow applications. The thin film and membrane technologies incorporate highly accurate temperature sensors and heaters as core elements of the sensors. IST AGs flow sensors are applicable in gas (liquids upon request), have an operating temperature range of -30 °C to +450 °C, and can measure low rate and direction from 0.0001 m/s (microflowSens) to 100 m/s (respectively from 1 mL/min to 10 L/min). In addition to measuring flow rates, our sensors can detect the presence of a liquid, biofilm or bubbles as well as indicate liquid level. Development channels guarantee the best possible adaptation of our sensors, whether in terms of dynamic range, response time, directional detection or ambient conditions.
Technical Library | 2019-06-06 00:19:02.0
More and more people and things are using electronic devices to communicate. Subsequently, many electronic products, in particular mobile base stations and core network nodes, need to handle enormous amounts of data per second. One important link in this communication chain is high speed pressfit connectors that are often used to connect mother boards and back planes in core network nodes. These new high speed pressfit connectors have several hundreds of thin, short and weak pins that are prone to damage. Small variations in via hole dimensions or hole plating thickness affect the connections; if the holes are too small, the pins may be bentor permanently deformed and if the holes are too large they will not form gas tight connections.The goal of this project was to understand how rework of these new high speed pressfit connectors affects connection strengths, hole wall deformations and plating cracks.
Technical Library | 2020-07-15 18:29:34.0
In the early 2000s the first fine-pitch ball grid array devices became popular with designers looking to pack as much horsepower into as small a space as possible. "Smaller is better" became the rule and with that the mechanical drilling world became severely impacted by available drill bit sizes, aspect ratios, and plating methodologies. First of all, the diameter of the drill needed to be in the 0.006" or smaller range due to the reduction of pad size and spacing pitch. Secondly, the aspect ratio (depth to diameter) became limited by drill flute length, positional accuracy, rigidity of the tools (to prevent breakage), and the throwing power of acid copper plating systems. And lastly, the plating needed to close up the hole as much as possible, which led to problems with voiding, incomplete fill, and gas/solution entrapment.
Technical Library | 2022-03-02 21:26:51.0
The solderability of a nickel-palladium-gold (Ni-Pd-Au) finish on a Cu substrate was evaluated for the Pb-free solder, 95.5Sn-3.9Ag-0.6 Cu (wt.%, abbreviated Sn-Ag-Cu) and the eutectic 63Sn-37 Pb (Sn-Pb) alloy. The solder temperature was 245ºC. The flux was a rosin-based mildly activated (RMA) solution. The Ni-Pd-Au finish was tested in the as-fabricated condition as well as after exposure to one of the following accelerated storage (shelf life) regiments: (1) 33.6, 67.2, or 336 hours in the Battelle Class 2 flowing gas environment or (2) 5, 16, or 24 hours of steam aging (88ºC, 90%RH).
Technical Library | 2015-07-16 17:24:23.0
Qualification of electronic hardware from a corrosion resistance standpoint has traditionally relied on stressing the hardware in a variety of environments. Before the development of tests based on mixed flowing gas (MFG), hardware was typically exposed to temperature-humidity cycling. In the pre-1980s era, component feature sizes were relatively large. Corrosion, while it did occur, did not in general degrade reliability. There were rare instances of the data center environments releasing corrosive gases and corroding hardware. One that got a lot of publicity was the corrosion by sulfur-bearing gases given off by data center carpeting. More often, corrosion was due to corrosive flux residues left on as-manufactured printed circuit boards (PCBs) that led to ion migration induced electrical shorting. Ion migration induced failures also occurred inside the PCBs due to poor laminate quality and moisture trapped in the laminate layers.
Technical Library | 2022-01-19 17:50:20.0
pH and oxygen electrochemical sensors were evaluated in a ventilatory hypoxia rabbit model. The ventilator hypoxia protocol included 3 differential phases: basal (100% FiO2), the hypoxia-acidosis period (10% FiO2) and recovery (100% FiO2). Sensors were tested in blood tissue (ex vivo sensing) and in muscular tissue (in vivo sensing). pH electrochemical and oxygen sensors were evaluated on the day of insertion (short-term evaluation) and pH electrochemical sensors were also tested after 5 days of insertion (long-term evaluation). pH and oxygen sensing were registered throughout the ventilatory hypoxia protocol (basal, hypoxia-acidosis, and recovery) and were compared with blood gas metabolites results from carotid artery catheterization (obtained with the EPOC blood analyzer).
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