23

1

Application Notes

PREHEAT & SOLDERING

The rate of preheat in production should not exceed 4°C/

second and a recommended maximum is about 2°C/second.

Temperature differential from preheat to soldering should not

exceed 100°C.

For further specific application or process advice, please consult

AVX.

COOLING

After soldering, the assembly should preferably be allowed

to cool naturally. In the event of assisted cooling, similar

conditions to those recommended for preheating should be

used.

HAND SOLDERING & REWORK

Hand soldering is permissible. Preheat of the PCB to 150°C is

required. The most preferable technique is to use hot air sol-

dering tools. Where a soldering iron is used, a temperature

controlled model not exceeding 30 watts should be used and

set to not more than 260°C.

RECOMMENDED SOLDERING

PROFILE

CLEANING RECOMMENDATIONS

Care should be taken to ensure that the devices are

thoroughly cleaned of flux residues, especially the space

beneath the device. Such residues may otherwise become

conductive and effectively offer a lossy bypass to the device.

Various recommended cleaning conditions (which must be

optimized for the flux system being used) are as follows:

Cleaning liquids. . . . . . . i-propanol, ethanol, acetylacetone,

water and other standard PCB

cleaning liquids.

Ultrasonic conditions . . power-20w/liter max.

frequency-20kHz to 45kHz.

Temperature . . . . . . . . . 80°C maximum (if not otherwise

limited by chosen solvent system).

Time . . . . . . . . . . . . . . . 5 minutes max.

STORAGE CONDITIONS

Recommended

storage

conditions

for

and

Temperature . . . . . . . . . . 15°C to 35°C

Humidity . . . . . . . . . . . . .

≤65%

Air Pressure . . . . . . . . . . 860mbar to 1060mbar

220

210

200

190

180

170

160

150

140

130

120

110

100

90

80

70

60

50

40

30

20

00.5

11.5

22.5

33.5

44.5

Assembly enters the

preheat zone

Additional soak time

to allow uniform

heating of the

substrate

Soak time

1) Activates the flux

2) Allows center of board

temperatures to catch up with

corners

45-60 sec.

above solder

melting point

Assembly exits heat–

no forced cooldown

186

°C solder melting

temperature

Time (mins)

0

2030405060708090

100

110

120

260

240

220

200

180

160

140

120

100

80

60

40

20

Time (seconds)

Enter Wave

Natural

Cooling

100

°C

3–5 seconds

10

0

20

40

60

80

100

120

140

160

180

200

215

°C

Time (minutes)

Preheat

Transfer from

preheat with

min. delay &

temp. loss

0

20

40

60

80

100

120

140

160

180

215

°C

Time (seconds)

Reflow

Enter

Vapor

Natural

Cooling

Duration varies

with thermal mass

of assembly

10–60 secs typical

10

20

30

40

50

60

70

200

IR REFLOW

WAVE SOLDERING

VAPOR PHASE