Multilayer Ceramic Capacitors Materials and Manufacture Written By: Manfred Kahn Abstract: The economical mass production of highquality, reliable and low-cost multilayer ceramic (MLC) capacitors requires a thorough understanding of the characteristics of the materials used, a knowledge of chemistry and electronics, as well as a high level of expertise in mechanical-equipment design and in-process technology.
Low-Voltage Performance of Multilayer Ceramic Capacitors Written By: N. H. Chan and B. S. Rawal Abstract: Extensive experiments and detailed analyses of the performance of multilayer ceramic capacitors used for decoupling and in other low-voltage, low-impedance applications discloses no degradation of insulation resistance in components without physical flaws. Capacitors with physical flaws show similar loss of performance at both low and high voltages.
Cracks: The Hidden Defect Written By: John Maxwell Abstract: Cracks in ceramic chip capacitors can be introduced at any process step during surface mount assembly. Thermal shock has become a “pat” answer for all of these cracks, but about 75 to 80% originate from other sources. These sources include pick and place machine centering jaws, vacuum pick up bit, board depanelization, unwarping boards after soldering, test fixtures, connector insulation, final assembly, as well as defective components. Each source has a unique signature in the type of crack that it develops so that each can be identified as the source of error.
Equivalent Series Resistance of Tantalum Capacitors Written By: R.W. Franklin Abstract: The resistive losses which occur with all practical forms of capacitor are made up from several different mechanisms, including resistance in components and contacts, viscous forces within the dielectric and defects producing bypassing current paths. To express the effect of these various factors on the behavior of an electrolytic capacitor they are lumped together as one term, the equivalent series resistance (ESR).
Conduction and Failure Mechanisms in Barium Titanate Based Ceramics Under Highly Accelerated Conditions Written By: B. S. Rawal and N. H. Chan Abstract: Various mid-K and high-K barium titanate based laboratory compositions were studied to understand the conduction and failure mechanisms in multilayer ceramic capacitors (MLCs). These studies were utilized to establish the failure modes, the cause of failures, and determine the voltage and temperature acceleration factors. Current voltage plots were evaluated to study the endurance of the various ceramics under stress. These observations were employed to develop test conditions to screen commercial parts with one to two orders of magnitude lower failure rates and study production processes and types of ceramic materials to further improve the reliability of MLCs
Surface Mount Ceramic Resonators Written By: Phil Elliott Abstract: Ceramic resonators provide an attractive alternative to quartz crystals for oscillation frequency stabilization in many applications. Their low cost, mechanical ruggedness and small size often outweigh the reduced precision to which frequencies can be controlled, when compared to quartz devices. Ceramic resonators are now available in surface mountable packages suitable for automated production processes.
Comparison of Multilayer Ceramic and Tantalum Capacitors Written By: Jeffrey Cain, Ph.D. Abstract: Engineers now have a choice between ceramic and tantalum when it comes to selecting capacitors with values between 0.1 – 22µF. As the ceramic material technology continues to advance, more and more capacitance is realized in the same case sizes compared to previous years. This paper will examine what devices are available and the trade off of using each of the technologies. The goal of this work is to help in selecting the proper device (tantalum versus ceramic) for a specific application.
Capacitor Array — An Integrated Passive Component Offering Benefits to the Automotive Sector Written By: Mark Stewart Abstract: By combining discrete capacitors into a multi-element package, AEC-Q qualified capacitor arrays offer automotive designers the opportunity to lower placement costs, increase assembly line output through lower component count per board and reduce real estate requirements.
The 3 Rs of IDCs: Reliability, Repeatability, Reparability Written By: Tom Anderson Abstract: Even after more than 50 years in the marketplace, insulation displacement connectors (IDCs) continue to prove themselves in new and demanding applications, such as automotive safety systems, solid-state lighting (SSL), and industrial sensors and controls. IDCs have provided a cost-effective and reliable alternative to crimp-to-wire and hard-soldering wires to a PCB.
Optimizing Antenna Performance Through the Use of High Q, Tight Tolerance Capacitors Written By: Ron Demcko Abstract: Antenna matching is an important aspect of any RF system. Thinking in traditional terms, a properly designed and matched antenna increases the operating distance of the wireless product. Well matched antennas can transmit more power from the radio – therefore transmit over longer distances. Likewise, a well matched antenna allows the maximum transfer of energy from the receiving antenna to the receiver front end. Thus, allowing better receive characteristics for the system. But the use of a capacitor can also have a big impact upon the physical size of an antenna. If the goal is a compact, integrated antenna, the use of a
Portable Electronics Require Smaller, More Modular SMT Battery Connectors Written By: Tom Anderson Abstract: Next-generation battery connectors face many new market demands, although the common ingredients remain the same: high life cycle, stability, simple design, and SMT compatibility.
Aluminum Electrolytic Capacitor Holder For Ruggedized Automotive Applications Written By: Tom Anderson Abstract: Harsh environments such as automotive and industrial applications can be very demanding on larger electronic components, which are exposed to severe shock and vibration requirements. In order to protect these components, extra attention and most often times cost needs to be devoted to the processing and mechanical attachment within the device to the Printed Circuit Board (PCB).
The Frequency Response Effects of Internal Component Configuration on Multiple Ceramic Dielectric System Written By: S. Pala | R. Demcko | M. Berolini Abstract: The purpose of this paper is to discuss the frequency response effects of internal designs within ceramic systems. Those effects will be related to component performance parameters for devices used to suppress ESD and control EMI in high speed data lines, which are prone to be damaged by ESD. As communication speed increase, systems become more complicated and performance standards tighten, options to improve EMI/RFI performance becomes of great importance. Long term EMI performance and reliability are of particular importance in automotive, medical and aviation application sectors. A performance comparison will be made between single element
SMT Process Characteristics of AVX TransGuards Written By: Ron Demcko Abstract: TransGuards are uniquely suited for wide-scale usage in SMT applications. TransGuards exhibit many advantages when used in SMT assemblies. This paper is a general guideline aimed at familiarizing users with the characteristics of soldering multilayer SMT ZnO TransGuards.
LCD Driver Circuit EMI Filtering Options Written By: Ron Demcko Abstract: A review of EMI filter component options, comparing product performance, device characteristics and related factors (eg PCB board area, placement cost, etc.).
Charge Control Methods for SuperCapacitors: Methods to Protect Power Sources from Damage Due to High Current Demands of SuperCapacitors Written By: Ron Demcko | Joe Hock | Ashley Stanziola | Daniel West Abstract: Circuit designs exploiting the increased energy storage provided by supercapacitors, requires careful consideration of the increased power handling, than that of batteries, when charging these devices. The unique composition of electrochemical double-layer capacitors (EDLC) inherently allows them to withstand large currents. Table 1 below is a brief list of AVX cylindrical (SCC) and series-connected module (SCM) SuperCapacitors, displaying peak current supply and sink current capability. These maximum specifications will typically exceed current capability of charge sources, and lead to failures within the power supply system. Supercapacitors have
