| COUNTRY
STANDARD AND TEST |
BRIEF
DESCRIPTION OF TEST METHOD |
STANDARD
REQUIREMENTS |
UK B.S. 441
(Corrosion) |
As
described in BS 5625. A chemically
cleaned copper sheet with a depression is used as the test piece. 1g
of the cored solder wire is formed into a flat spiral, placed in the
center of the depression and heated to 50°C above the liquidus of
the solder until the solder melts. Heating is maintained for a
further 5 seconds. After cooling for 15mins the test piece is placed
in a humidity chamber operating at 40°C, 93% R.H. for 72 hrs and
then examined. |
No Corrosion or
Pitting |
| Halide % w/w |
0.5g of the
flux is extracted from the cored solder with hot alcohol. After
evaporating the bulk of the solvent, the halide content (calculated
as chloride) is determined by titration with silver nitrate
solution. |
(Class 6 Grade 3)
Nil |
| Hardness of
Residues |
A specimen
joint is cooled for up to 30 minutes and the flux residue assessed. |
It must
not be readily indented by the finger nail nor prevent powdered
chalk from being readily removed. |
| UK D.T.D.
599A (Corrosion) |
Two
abrasion cleaned copper sheets are mounted 6mm apart, the lower
sheet having a depression into which 1g of cored solder is placed.
The test piece is heated until the solder melts, cooled, placed in a
humidity cabinet at 100% RH and ambient temperature for 24hrs and
then examined for evidence of corrosion and for homogeneity and
deliquescence of the flux residues. |
No Corrosion or
Deliquescence. |
| Insulation
Resistance |
A trough with
conductors at each end in a PTFE block is filled with flux and the
insulation resistance at 500 volts is measured between the
conductors 1 hour and 24 hours after filling and after a further 24
hours in a humidity cabinet at 100% RH and ambient temperature. |
>1,000 megohm |
U.S.A
QQ-S-571E
(Water Extract Resistivity) |
The
flux is extracted from the cored solder
with hot isopropanol and 0.1cc of a 35% solids flux solution is
added to each of three clean beakers containing water of minimum
resistivity 500,000 ohm-cm. The contents of each beaker are boiled
for 1 minute, cooled rapidly and the resistivety of the water
measured. |
Type R&RMA
100,000
ohm-cm minimum |
Type RA
50,000
ohm-cm minimum |
| Spread Factor |
Types R and RMA. Five thin, acid cleaned, copper sheets are
oxidized at150°C A
0.5g ring of cored Sn60 solder is placed on each test piece which is
then heated at 205°C for 6 minutes. The height (Hcm) of each solder
spot is measured and the spread factor expressed as a function of
D-H
x100%
D
Where D is the diameter of a sphere of solder of the same weight. |
80% minimum |
| |
Type RA As above but
with oxidising temperature of 205°C |
80% minimum
|
| Chlorides and
Bromides |
One drop of
flux solution obtained by extraction with hot isopropanol is placed
on a piece of silver chromate paper. After 15 minutes the paper is
washed in isopropanol, dried for 10 minutes and examined for colour
change. |
Type R & Type
RMA Should not discolour silver chromate paper. |
| Solder Pool |
0.2g of cored
solder is placed on each of three, acid cleaned, thick copper sheets
which are then heated at 315°C until the solder melts. The solder
pool is examined for thickness of edge and the coupons for flux
splattering. |
Should not spit,
feathers to a thin edge. |
| Copper Mirror Test |
Types R and
RMA 0.05 ml each of 35% w/w solutions in isopropanol of the flux and
rosin are placed on a copper film, vacuum deposited on to glass. The
mirror is placed horizontally in a humidity chamber at 23°C and 50%
RH for 24 hours. The flux is removed from the mirror with
isopropanol and the mirror examined. |
Must not have
completely removed the copper mirror |
GERMANY DIN
8516
Area of Spread |
0.5g
of cored solder wound into a
spiral, is placed on an etched brass sheet, which is then heated at
310°C for 5 seconds. The area covered by the solder is measured on
10 such sheets and averaged. There are different requirements for
types F-SW 32 and F-SW 26. |
80 - 200 mm² |
Corrosion
F-SW
31 and F-SW 32 |
F-SW 31 and
F-SW 32 1g of cored solder is placed inside a halved tube of
abrasion cleaned steel which is then heated at 300°C for 1 minute.
The halves of the tube are separated and placed in a humidity
cabinet at 83% RH and 23°C for 14 days. The inside surfaces of the
tubes are examined for signs of corrosion. When testing F-SW 32 a
parallel test with F-SW 31 for flux cored solder is carried out. For
fluxes to F-SW 26 the tests can be carried out inside a halved tube
of abrasion cleaned copper. |
F-SW 31 & F-SW
32
Nil on Steel
F-SW 26
Nil on Copper |
