IEC 60384-22:2011 pdf – Fixed capacitors for use in electronic equipment – Part 22: Sectional specification -Fixed surface mount multilayer capacitors ofceramic dielectric, Class 2.
4 Test and measurement procedures
This clause supplements the information given in IEC 60384-1, Clause 4.
4.1 SpecIal preconditioning
Unless otherwise specified in the detail specification, the special preconditioning, when specified in this sectional specification before a lest or a sequence of test, shall be carried Out under the following conditions.
Exposure at upper category temperature or at Such higher temperature as may be specified in the detail specification durIng 1 h, followed by recovery durIng (24 ± 1) h under standard atmospheric condition for testing.
NOTE Capacitors lose capacitance continuously with lime according to a logarithmic law (this is called ageeng), However, ii the capacitor is heated to a lemperalwe above the Curie point of its ditaclric, then ‘deageing’ lakes place, I.e. the capacitance lost through agelng Is regained, and ageing’ recommences from the time when tile capacilor recools. The purpose of special preconditioning Is to bring the capacitor to a defined state regardless of Its previous history. (See Clause B.4 for further Information).
4.2 MeasurIng conditions See IEC 60384-1, 4.2.1.
4.3 Mounting
See lEG 60384-1, 4.33.
4.4 Visual examination and check of dimensions See lEG 60384-1, 4.4. with the tollowing details.
4.4.1 Visual examination
A visual examination shall be carried out with suitable equipment with approximately 10* magnification and lighting appropriate to the specimen under test and the quality level required.
NOTE The operalor should have available facilities for incident or transmitted Illumination as well as an appropriate measuring lacility
4.4.2 RequIrements
Quantitative values for the requirements below may be given In the detail or In the manufacturer’s specification.
4.4.2.1 RequIrements for the ceramic
a) Be free of cracks or fissures, except small damages on the surface, which do not deteriorate the performance of the capacitor. (Examples: see Figures 1 and 2).
4.9 Resistance to soldering heat See IEC 60068-2-58 with Ihe following details.
4.9.1 SpecIal preconditloning See 4.1.
4.9.2 InItial measurement
The capacitance shall be measured according to 4,5.1,
49.3 Test conditions
4.9.3.1 Solder bath method (applicable to 1608U. 2012M and 32161.1)
NOTE S.. TabI. A.1 lot .xpIantiri of the size code.
See IEC 60068-2-58, Clauses 6 and 8, with the following details, if not otherwise specified in
the detail specification.
The specimen shall be preheated to a temperature of (110 to 140) °C and maintained for 30 5 to 60s.
Solder alloy: Sn-Pb or Sn-Ag-Cu
Temperature: 260 C ± 5 C
Duration of immersion: 10 s ± 1 s
Depth of Immersion: 10 mm
Number of immersions: 1
49,3.2 Infrared and forced gas convection soldering system
See IEC 60068•2-58. Clauses 7 and 8. with the following details:
a) the solder paste shall be applied to the test substrate;
b) the thickness of solder deposit shall be specified in the detail specification;
c) the terminations of the specimen shall be placed on the solder paste:
d) solder alloy: Sn-Pb:
unless otherwise specified in the detail specification, the specimen and test substrate shall be preheated to a temperature of (150 ± 10) C and maintained for 60 s to 120 $ in infrared and forced gas convection soldering system:
the temperature of the reflow system shall be quickly raised until the specimen has reached (235 ± 5) °C and maintained at this temperature for (10 1) S. Number of each test: 1, unless otherwise specified in the detail specification;
e) solder alloy: Sn-Ag-Cu;
unless otherwise specified in the detail specification, reflow temperature profile shall be selected from Table 11 and Figure 6:
f)number of each test: 1, unless otherwise specified in the detail specification;g) the temperature profile of d) or e) shall be specified in the detail specification.4.9.4Recovery
The capacitors shall recover for 24 h ± 2 h.
The flux residues shall be removed with a suitable solvent.4.9.5 Final inspection, measurements and requirements
After recovery，the capacitors shall be visually examined and measured and shall meet thefollowing requirements:
Under normal lighting and approximately 10x magnification, there shall be no signs of damagesuch as cracks.
Dissolution of the end face plating (leaching) shall not exceed 25 % of the length of the edgeconcerned.The detail specification may prescribe further details.
The capacitance shall be measured according to 4.5.1 and the change shall not exceed thevalues in Table 12.