Dictionary – Know Your Resistors

Adhesion: The ability of dissimilar metals or particles to cling together as a joint is referred to as adhesion. Adhesion in the thick film is created by either a chemical (oxide bonded) or mechanical (Frit) bonds. Peel tests can be used to measure adhesion between lead and substrate and dielectric. Alpha coefficient: In a thermally sensitive resistor or Thermistor applications, the alpha (?) coefficient is a material characteristic that defines the percentage resistance change per degree centigrade. It is also known as the temperature coefficient and it's calculated by the following relationship; ? = 1/RT x dR/dT Where RT is the resistance of the component at the relevant temperature in (°C), dR/dT is the gradient of the R vs. T curve at that temperature point and alpha is expressed in (%/°C) Annealing: Annealing is a heat process whereby a material (metal or glass) is heated to a specific temperature (annealed point) and then allowed to cool slowly in order to maintain ductility and prevent crack and internal stress. Aspect Ratio (AR): The ratio of resistor length to resistor width is the aspect ratio. It's also known as the number of squares. Amplitude Balance: The maximum deviation or difference in amplitude [...]

2017-10-24T19:02:04+00:00October 24th, 2015|Tech Info|

Understanding The Basic Thermal Properties of SMT Devices

Ensuring optimal RF performance (that is, mechanical, thermal and electrical performance) of a surface-mount technology (SMT) ceramic device requires the careful procurement and use of consistently well-behaved materials, the use of proper and rigorous design principles, and proper attention paid to the appropriate parameters (on the part of the manufacturer in its design, and on the part of the user in its operation). In this way, the reflection, dissipation, and transmission signatures of the device in question remain consistently and predictably well behaved. Some instances of devices that are designed to maximize dissipative loss are terminations, loads, absorptive filters and dividers, etc. Typically, these devices must minimize reflective loss (regardless of the nature of the signals at their inputs), which, when combined with proper dissipative design, results in an optimal transmission signature as well. SMT devices that are non-dissipative by design are hybrid couplers, power dividers, filters, etc. Filters, of course, are designed such that some signals are to experience a minimum of reflection and dissipation while maximizing transmission, whereas other signals are to experience a maximum of reflection while minimizing transmission. Other dissipative devices are attenuators, voltage dropping resistors, resistive splitters, etc. Attenuators must be designed such that reflective [...]

2017-10-25T14:12:34+00:00September 25th, 2015|Tech Info|

How To Manually Solder Chip Resistor Components

Considerations for proper soldering methods and techniques of chip resistors. Soldering is the process of using a metal alloy with a low melting temperature to fuse or ‘solder' the electrical contacts of a component to the pads on a circuitboard. Proper soldering enhances the strength and conductivity of the connection. Poor soldering can result in weak connections, higher resistance that causes heat buildup at the connection, and possible failure of the component. Did you also know that hermetically sealed circuit boards are useful for projects with complex computations? A hermetic seal is widely used in applications that require light and compact sealing methods such as missiles or bomb fuses. You can find more information and get a circuit board sealer here. The type of components and the pads to which they will be attached dictate the appropriate soldering method. The correct amount and duration of heat to be applied are determined by the component, the circuit board, the solder pads, the solder and flux, and the environment in which the soldering takes place. For this reason, effective soldering requires reasonable controls. Some experimentation is required to determine the optimal conditions for each specific application. General Soldering Guidelines: All soldering applications [...]

2017-10-25T16:33:00+00:00August 24th, 2015|Tech Info|

Typical Soldering Profile For IMS Solderable Components

Temperature/Duration Limit Recommendations PEAK TEMPERATURE TIME 260 deg C (500 deg F) 5 Seconds 250 deg C (482 deg F) 10 Seconds 240 deg C (464 deg F) 20 Seconds 230 deg C (446 deg F) 30 Seconds 204 deg C (400 deg F) 40 Seconds Although specific applications will vary and many other variables will need to be considered such as board type, adjacent components, and delivery methods for the solder, using a standard Mil grade solder (ie. SN-62) and a good Mil grade RA or RMA flux, the profile depicted above will typically give good results. Note: Regarding Aluminum Nitride Components: ALN is very thermally conductive. Contact style soldering methods that do not consider the heat-sync properties of these high thermally conductive components (ie. Soldering irons and hot air column heating methods) can be difficult to use. Best results occur with hot plate reflow, or belt or chamber reflow methods. ALN has a TC of 170 W/ m/ °K and this high heat conductivity can cool soldering iron tips the instant they come into contact with the component which often results in turning up the heat on the iron much too high to compensate. Download our tech note [...]

2017-10-25T16:37:44+00:00July 24th, 2015|Tech Info|

IMK Series Resistive Coupler

Broadband Low-Loss Device IMK Series Resistive Couplers provide the sensing function over a broad range of frequencies in a compact, easy to use component. Insertion loss is comparable to the more complicated frequency sensitive couplers. Like IMS attenuators, the IMK Series is engineered to optimize performance in two ways: 1) Resistive areas are constant and are specified for the lowest dB value ensuring that all couplers easily handle the incident RF power. 2) High inductive lines are specified to minimize ground path leakage and maintain low through loss. IMK Series Specifications Insertion Loss (1 -2): 1dB or less (values greater than 18dB) Coupling Range: 6 - 30dB Standard Size: 0.120” x 0.120” x 0.035” MAX Impedance: 50Ω Operating Frequency: DC - 20GHz dB Flatness: See data on below or on data sheet Operating Temperature: -55°C to 150°C Dissipated Power: 1W (at 100°C baseplate temperature) Through Power: 5W (Value Dependant) VSWR (main line): 1.2:1 depending on implementation As with most IMS products: You can order any quantity over 100 pieces You can order any quantity on tape & reel over 1,000 pieces  

2017-10-24T19:02:34+00:00April 25th, 2015|New Products|

IMS Introduces HVI Series High Voltage Surface Mount Chip Resistors to 3kV

Press Release For Release January 30, 2013 Press Contact: Barry Black Tel. +401.683.9700 E-mail: bsblack@ims-resistors.com Portsmouth, Rhode Island, USA – International Manufacturing Services, Inc. (IMS), a leading manufacturer and supplier of high quality thick film resistors, terminations, attenuators, couplers, thermal management devices, planar dividers and planar filters to the electronics industry, introduces their line of HVI Series chip resistors especially suited for high voltage applications. The HVI Series are offered in sizes 0402 to 2512, values to 1Gohm and tolerances to 1%. These resistors feature a nickel barrier layer for excellent solder leach resistance and proprietary thick film architecture allowing the 2512 size to withstand a continuous 3kV and overload of 4kV. Applications for the HVI Series high voltage chip resistors include but are not limited to power supplies, power converters, defibrillators, sensors, detectors, pacemakers and power meters. Samples are available by contacting the factory or visiting their website. Since 1974, IMS has been supplying the electronics manufacturing industries with highest quality thick and thin film chip resistors, terminations, attenuators, couplers, thermal management devices and other RF and Microwave components. For more information, visit www.imsresistors. com, or contact the company at 50 Schoolhouse Lane, Portsmouth, RI, 02871 USA, Tel. 401-683-9700. [...]

2018-01-11T15:05:36+00:00November 30th, 2014|New Products, Press Release|

IMS Introduces Non-Magnetic Chip Resistors with Ultra Leach Resistant Terminals for MRI Applications

Portsmouth, Rhode Island, USA – International Manufacturing Services, Inc. (IMS), a leading manufacturer of high quality thick film resistors, terminations, attenuators, couplers, thermal management devices, planar dividers and planar filters to the electronics industry, has introduced a new type or chip resistor terminal which are non-magnetic and ultra leach resistant. The Ultra Leach Resistant (ULR) type terminals have been proven to maintain their integrity in the harshest solder environments, including high temperature and multiple reflows, withstanding up to 15 minutes at 260°C. The ULR metallization gives customers ultimate solder leach resistance without the need for ferro-resonant Nickel Barrier terminals. The leach resistance of ULR type terminals is far superior to Ni-Barrier at a lower cost than Copper Barrier components. These rugged terminals are available in RoHS and lead content versions on resistor sizes 0402 to 6227, values 1 to 1T and operating frequency to 40GHz. Chip resistors with ULR terminals are ideal for any application including but not limited to MRI Coils, NMR imaging and cryogenics. Since 1974, IMS has been supplying the electronics manufacturing industries with highest quality thick and thin film chip  resistors, terminations, attenuators, couplers, thermal management devices and other RF and Microwave components. For more information contact [...]

2017-10-25T16:13:15+00:00March 22nd, 2013|New Products, Press Release, Tech Info|
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