Mechanical and climatic test methods
IEC 60749-15-2020 pdf download.Semiconductor devices — Mechanical and climatic test methods — Part 15: Resistance to soldering temperature for through-hole mounted devices
Dispositifs a semiconducteurs — Méthodes d’essais mecaniques et climatiques — Partie 15: Résistance a Ia temperature de brasage pour dispositifs par trous traversants.
The solder shall not contain impurities which will adversely affect its properties.
Other solders and their applicable bath temperatures may be used as detailed in the relevant specification.
5.2 Flux
If flux is applied prior to solder dipping, the flux shall consist of 25 % by weight of colophony in 75 % by weight of isopropyl alcohol, unless otherwise detailed in the relevant specification.
6 Procedure
6.1 Test method
The method used in this procedure requires the specimen to be dipped into a solder bath under specified conditions. The solder bath method is the one which simulates most closely the soldering procedures of flow soldering and similar soldering processes. In circumstances where the solder dip method is considered to impracticable the specimen can be tested by the application of a heated soldering iron under controlled conditions. This is described in
IEC 60068-2-20.
6.2 Ageing and pre-conditioning of specimens
If required by the relevant specification, the test conditioning shall be preceded by accelerated ageing such as steam ageing, damp heat conditioning, dry heat conditioning or unsaturated pressurized vapour conditioning. Accelerated ageing shall be performed in accordance with IEC 60068-2-20.
Any other special pre-conditioning of the specimens prior to testing shall be as detailed in the relevant specification. This preparation may Include operations such as bending or other relocation of leads, and the attachment of heat sinks or protective shielding prior to solder dipping.
6.3 Preparation of the solder bath
The molten solder shall be stirred to assure that the temperature is uniform. The dross shall be skimmed from the surface of the molten solder just prior to dipping the part.
6.4 Use of flux
Where detailed in the relevant specification, all leads of the specimen shall be dipped in flux prior to solder dip; excess flux shall be removed by draining for a suitable time.
6.5 Solder dip
The part shall be attached to the dipping device (see 4.2) and the leads immersed in the molten solder to within 1 mm of the body of the device under test. The parameters for solder temperature, dwell time, number of immersions and rates of immersion and emersion are defined in Table 1. After the dipping process, the part shall be allowed to cool in air and, if flux has been used, residues shall be removed with isopropanol or ethanol.
6.6 Precautions
Prior to and after the solder immersion, precautionary measures shall be taken to prevent undue exposure of the part to the heat radiated by the solder bath.
6.7 Measurements
Hermeticity tests for hermetic devices and visual examination shall be made in accordance with IEC 60749-8 and IEC 60749-3 respectively. Electrical measurements that consist of parametric and functional tests shall be made as required by the relevant specification.
6.8 Failure criteria
A device shall be defined as a failure if hermeticity for hermetic devices cannot be demonstrated in accordance with IEC 60749-8, Mechanical damage such as cracking, chipping or breaking of the package (to be Inspected with a magnification of 10* to 20*) and failure to meet the requirements of IEC 60749-3 will also be considered a failure, provided such damage was not induced by fixturing or handling. Devices shall be classified as failures if parametric limits are exceeded or if functionality cannot be demonstrated under nominal and worst-case conditions specified in the relevant specification.
7 Summary
The following details shall be specified in the relevant specification:
a) use of heatsinks or shielding, If applicable (see 4.3);
b) flux composition, if applicable (see 5.2);
C) solder composition, if other than detailed in this document (see 5.1);
d) pre-conditioning of specimens, if applicable (see 6.2);
e) time of immersion and number of immersions, if other than as specified in Table 1;
f) depth of immersion if other than specified in 6.5;
g) failure criteria of electrical measurements (see 6.8);
h) sample size.IEC 60749-15-2020 pdf download.