Thermal effects in embedded thin- and thick-film resistors in comparison to chip resistors (original) (raw)
Related papers
Environmental tests of embedded thin- and thick-film resistors in comparison to chip resistors
Circuit World, 2014
In this work environmental behavior of resistors embedded into Printed Circuit Boards (PCBs) and discrete chip resistors assembled to standard PCBs are co mpared. The investigations were based on the thin-film resistors made of NiP alloy, thick-film resistors made of carbon or carbon-silver inks as well as chip resistors in 0402 and 0603 packages. Thin-and thickfilm resistors were made in the bar form. In addition, poly mer thick-film resistive films were screen-printed on the several types finishing materials of contact terminations such as copper, silver, and gold. To determine the sensitivity of embedded resistors versus s tandard assembled chip resistors on environmental exposure the climatic chamber was used. The measurements of resistance were carried out periodically during the tests, and after the exposure cycles.
Microelectronics Reliability, 2012
Embedding passive components into multilayer printed wiring boards (PWBs) meet electronic device requirements concerning the necessity of saving the surface board area for active elements, reducing board's size, improving device functionality and safety as well as overall product cost reduction. Since embedded components cannot be replaced after the board is completed, a long term stability and reliability are the important concerns for manufactures. This paper presents the results of examinations of embedded thin-film NiP resistors and polymer thickfilm resistors during their continuous operation and the influence of temperature on the resistance values after the simulation of a lead-free soldering process and after the temperature cycling test (À40 C/+85 C).
Stability of thin-film resistors embedded in printed circuit boards
2011 International Students and Young Scientists Workshop "Photonics and Microsystems", 2011
Long-term stability of embedded passives is very important issue. To determine this matter an aging process can be used, where test samples are exposed to environmental conditions. Objecti ve of this research was analyzing reliability of thin-fil m resistors based on Ohmega-Ply® technol ogy. Resistive material was a nickelphosphorus (Ni-P) alloy (wi th sheet resistance 25 Ω/sq or 100 Ω/sq) on FR-4 substrate. A number of vari ables were considered in this study (sheet resistance, geometry of resistor, type of cl adding, l aser trimming, pulse stress and environmental conditi ons). Two di fferent accelerated ageing processes-Ex-Situ (samples exposed to elevated temperature and/or rel ati ve humi di ty but resistance measurements made at room temperature) and In-Situ (resistance of test samples performed directly at the ageing condi tions) were carried out to perform long-term behavior analysis. The results revealed a significant influence of thickness of resistor, type of cladding and temperature on stability of investigated structures. Signification of other factors was negligible.
Steady-state and transient thermal properties of resistors embedded in printed circuit boards
This work presents experimental results of static and transient thermal characterisation of thin-film resistors embedded in printed circuit boards and commercial discrete resistors. Objects of study were differ in sheet resistance, size or topology. Temperature on the test sample surface was determined based on thermographic measurement. Based on experimental results maximal surface temperature was found. Moreover thermal time constant was evaluated which can be helpful to determine how quickly temperature is getting at equilibrium state. Conclusions of this work can be helpful to define thermal behaviour and maximum power dissipation of the resistors embedded in printed circuit boards.
Environmental qualification testing and failure analysis of embedded resistors
IEEE Transactions on Advanced Packaging, 2005
Embedding passive components (capacitors, resistors, and inductors) within printed wiring boards (PWBs) is one of a series of technology advances enabling performance increases, size and weight reductions, and potentially economic advantages in electronic systems. This paper explores the reliability testing and subsequent failure analysis for laser-trimmed Gould subtractive nickel chromium and MacDermid additive nickel phosphorous embedded resistor technologies within a PWB. Laser-trimmed resistors that have been "reworked" using an inkjet printing process to add material to their surface to reduce resistance have also been considered. Environmental qualification testing performed included: thermal characterization, stabilization bake, temperature cycling, thermal shock and temperature/humidity aging. In addition, a pre/post-lamination analysis was performed to determine the effects of the board manufacturing process on the embedded resistors. A failure analysis consisting of optical inspection, scanning acoustic microscope (SAM) and environmental scanning electron microscope (ESEM) imaging, and PWB cross-sectioning was employed to determine failure mechanisms. All the embedded resistors were trimmed and the test samples included resistors fabricated both parallel and perpendicular to the weave of the board dielectric material. Material stability assessment and a comparison with discrete resistor technologies was performed.
Electrical properties of thin-film resistors in a wide temperature range
Circuit World, 2015
Purpose -The purpose of this paper is to characterise electrical properties of Ni-P thin-film resistors made on FR-4 laminate in a wide range of temperature (fro m -180 to 20ºC). Design/methodolog y/approach -The study was performed using resistors made of nickel-phosphorus (Ni-P) foil with two different thicknesses (0.1 μm or 0.05 μm) and the same different sheet resistances (100 oh m/sq or 250 ohm/sq). The resistance rectangular resistors had length and width fro m the range between 0.59 and 5.91 mm. The resistance vs temperature characteristics and their distribution as well as resistors durability to low-temperature thermal shocks were investigated.
Selected properties of multi-terminal resistors embedded in printed circuit boards
Electron Technology Conference 2013, 2013
Modern electronic devices are more and more complex and multifunctional. It could be done by producing faster and more reliable active components and increasing number of passives and interconnections' density. To form such complex devices one can embed components in substrate of printed circuit board (PCB) or build multilayer boards. The other way is to form multi-terminal passive components to spare free surface and decrease number of interconnections. Authors created three-terminal thin-film (TF) resistors embedded in PCBs and investigated their selected properties such as resistance repeatability, long term stability, pulse durability and thermal characteristics.
Circuit World, 2014
This work presents the results of the thermal analysis of cermet resistors made on alu mina or LTCC substrate and polymer thick-film resistors embedded in FR-4 substrate. The research was carried out with an addit ional consideration of such factors as sheet resistance (which depended on the type of resistive paste), the size and topology of element and the kind of contact material (Cu, Ag or Ni/Au). A few key points on the element were specified fo r wh ich a mo re thorough analysis were carried out. The results were approximated by physically acceptable function which allowed to determine the influence of different mechanis ms of heat transfer, and determine their t ime and thermal constants .