BS EN 62490-1-2010 pdf download.ESL measuring method Part 1 : Capacitors with lead terminal for use in electronic equipment.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60384-1:2008, Fixed capacitors for use in electronic equipment — Part 1: Generic specification
3 Terms and definitions
For the purpose of this document, the terms and definitions given in lC 60384-1 and the following apply.
3.1
equivalent series Inductance L
ESL
inductive part of the impedance of capacitors
NOTE 1 The unit of ESL is Henry (H).
4 Measurement jig, short compensation jig, and spacer
4.1 Measurement jig (test fixture)
The measurement jig shall have the following features:
a) the lead terminal holding method shall be screw up:
b) the measurement jig has two pairs of screw-fixation electrodes for fixing the lead terminals of the capacitor to be measured. In pairs, one of the electrodes is fixed to the measurement jig and the other is adjustable for fixing the lead wire. The adjustable electrode shall move only in a direction to hold the lead terminal and shall not rotate around the electrode fixing screw.
4.2 Short compensation jig
The short compensation jig shall be the lead wire rod which has the following features of the materials and dimensions, which includes the diameter or the cross-section area:
a) materials shall be the same materials as the lead wire of the capacitor to be measured;
b) shape shall be as shown in Figure 1;
5.1 Measuring Instrument
The impedance analyser (balance bridge method) with the following specification or equivalent shall be used:
a) inductance value (ESL) can be measured at a frequency of 40 MHz or higher;
b) basic impedance accuracy shall be ±0,08 % or better;
c) impedance value of 3 m1 or less can be measured.
5.2 Measurement conditions
The measurements shall be made under the standard atmospheric conditions for testing, as specified in IEC 60384-1:2008, 4.2.1. In addition, if there is any doubt as to the validity of measurement, the recovery conditions, as specified in IEC 60384-1:2008, 4.2.2, shall be implemented.
5.3 Preparation of sample
The lead terminals of a capacitor to be measured shall be cut at a length of 5 mm to 10 mm.
When cutting the lead terminals, the lead terminal shall be kept from bending.
NOTE By cutting the leads shorter, they make stable contact with the measurement electrodes and provide highly
repeatability and reproducibility.
5.4 Measurement points
The measurement points of ESL shall be the places of the seating plane or flange of the
capacitor to be measured. An example is shown in Figure 3.
NOTE Although during measurement the spacer is used, the measured value is equivalent to the value that would be measured at the seating plane of the lead terminals of capacitors as shown In Annex A.
Unless otherwise specified in the product specification, the frequency and signal shall be as follows:
a) the measurement frequency shall be 40 MHz;
b) the signal level of an oscillation of a measuring instrument shall be 0.5 V to 1,0 V in r.m.s.
5.6 Measurement procedure
5.6.1 General
The measurement shall be performed in the order of open compensation, short compensation, and ESL measurement of the capacitor. Before beginning the procedure, the number of times to average and integration time shall be set so that measurement accuracy in less than 2 %.
NOTE Increasing the number of times to average and integration time increases repeatability and reproducibility.
5.6.2 Open compensation
Connect the measurement jig specified in 4.1 to the measuring instrument and tighten the screw for adjustable electrode with nothing in between the electrodes. Perform open compensation according to the instructions for the measuring instrument.
5.6.3 Short compensation
The test fixture specified in 4.1 shall be connected to the measuring instrument and the short compensation jig specified in 4.2 with the short compensation spacer shall be fixed in between the electrodes by tightening the screws. Then the short compensation shall be performed according to the instruction of the measurement instrument. Example of short compensation shall be as shown In Figure 4.BS EN 62490-1-2010 pdf download.