IEC 61189-5-601:2021 pdf free download Test methods for electrical materials, printed boards and other interconnection structures and assemblies – Part 5-601: General test methods for materials and assemblies – Reflow soldering ability test for solder joint, and reflow heat resistance test for printed boards
5.2 Test substrate The test substrate material shall be single or double-sided mounting with single-layer, double- layer or multilayer printed boards for material structure used with product. Unless otherwise specified in the product specification, the test substrate shall be as follows.
a) Test substrate material Test substrate material shall be a single-sided printed board for general use, for example, copper-clad epoxide woven fiberglass reinforced laminated sheets as specified in IEC 61249-2-7 or IEC 61249-2-8. The thickness shall be (1,6 ± 0,2) mm including copper foil. The copper foil thickness shall be (35 ± 10) µm.
b) Test substrate dimensions The test substrate dimensions depend on the mounted package size and shape. However, the test substrate dimensions shall be able to be fixed on the pull strength test equipment.
c) Land shape and land dimensions Land shape and land dimensions should be the same specification as used for product design. Land shape and land dimensions should be as specified in IEC 61188-5-8. Moreover, the test substrate and the test package shall be designed in such a way that their land pattern forms a daisy chain circuit after mounting for the electrical continuity measurement.
d) Surface finish of land pattern If specified in the product specification, the surface finish treatment (for land pattern of the printed board) shall be the same as specified in the product specification. EXAMPLE: organic solderability preservative (OSP) or electroless nickel immersion gold (ENIG) plating layer.
5.3 Solder paste Solder paste is made of flux, finely divided particles of solder, and additives to promote wetting and to control viscosity, tackiness, slumping, drying rate, etc. Unless otherwise specified in the product specification, one of the solder alloys listed below (as specified in IEC 61190-1-3) shall be used. The product specification shall specify details of the solder paste.
The major composition of the solder alloys are as follows:
a) 63 % mass fraction of Sn (tin) and 37 % mass fraction of Pb (lead);
b) from 3,0 % to 4,0 % mass fraction of Ag (silver), from 0,5 % to 1,0 % mass fraction of Cu (copper) and the remainder of Sn (tin).
EXAMPLE: Sn-Ag-Cu ternary alloy such as Sn96,5Ag3Cu,5 alloy is used.
Solder paste shall be properly stored in accordance with the product’s specification.
5.4 Solder ball
The diameter and height of the solder ball used should be the following size a) and b) and the shape should be as shown in Figure 7. The composition should be equivalent to the one indicated in IEC 61190-1-3.