Publication detail

Thick Film Resistors Testing by Electro-Ultrasonic Spectroscopy

SEDLÁKOVÁ, V. ŠIKULA, J.

Original Title

Thick Film Resistors Testing by Electro-Ultrasonic Spectroscopy

Type

conference paper

Language

English

Original Abstract

The paper presents new principle of non-destructive testing of thick film resistors. Tested sample is excited by harmonic AC electrical signal with frequency fE and by the ultrasonic wave with frequency fU. On the interface between two conducting particles the intermodulation signal with frequency fm given by superposition or subtraction of exciting frequencies fE and fU is created. The main advantage of this method is the detection of electrical signal on the frequency different from frequencies of excitation signals. We have studied the properties of polymer based thick film layers and cermet thick film resistors. Polymer based samples were made using different resistive pastes and dipping silvers. The mixture of carbon and graphite conducting particles and silver flakes suspended in different polymer vehicles were used for the resistive pastes and dipping silvers (DiAg), respectively. Amplitude of intermodulation signal Am, noise and non-linearity depend on the properties of point contacts between conducting grains in the thick film layer. The intermodulation component of frequency fm = fE - fU varies linearly with electric excitation and quadratic dependence on ultrasonic excitation was observed. Cermet resistors were made with DuPont resistive paste DP2041 with sheet resistance 10 k square. We have used short current pulse from capacitor discharge as a stressing method for resistor degradation. We have measured the amplitude of intermodulation signal Am and non-linearity of cermet resistors before and after the pulse stressing. Standard measuring method of resistor quality is based on the distortion of pure harmonic signal by the nonlinearity of resistance. We have applied the signal of frequency 10 kHz and we measured the response on frequency 30 kHz as the third harmonic voltage (THV). The sensitivity of electro-ultrasonic spectroscopy on the sample degradation is high - the amplitude of intermodulation component Am increases approximately 6times, while the THV value changes for less than 5%.

Keywords

Electro-Ultrasonic Spectroscopy, Polymer, cermet, TFR

Authors

SEDLÁKOVÁ, V.; ŠIKULA, J.

RIV year

2007

Released

2. 1. 2007

Publisher

Electronic Components, Assemblies&Materials Association

Location

USA

ISBN

0-7908-0114-0

Book

Proceedings of CARTS USA 2007

Pages from

321

Pages to

328

Pages count

8

BibTex

@inproceedings{BUT27972,
  author="Vlasta {Sedláková} and Josef {Šikula}",
  title="Thick Film Resistors Testing by Electro-Ultrasonic Spectroscopy",
  booktitle="Proceedings of CARTS USA 2007",
  year="2007",
  pages="321--328",
  publisher="Electronic Components, Assemblies&Materials Association",
  address="USA",
  isbn="0-7908-0114-0"
}