STORAGE

Good solderability is maintained for at least twelve months,

provided the components are stored in their “as received”

packaging at less than 40°C and 70% RH.

SOLDERABILITY / LEACHING

Terminations to be well soldered after immersion in a 60/40

tin/lead solder bath at 235 ± 5°C for 2 ± 1 seconds.

Terminations will resist leaching for at least the immersion

times and conditions recommendations shown below.

NB products are compatible with a wide range of soldering

conditions consistent with good manufacturing practice for

surface mount components. This includes Pb free reflow

processes

with

peak

temperatures

up

to

270ºC.

Recommended profiles for reflow and wave soldering are

shown below for reference.

NC products are recommended for lead soldering application

or gluing techniques.

Surface Mounting Guide

Chip Thermistor – Application Notes

REFLOW SOLDERING

WAVE SOLDERING

18

P/N

Termination

Solder

Solder

Immersion

Type

Tin/Lead

Temp ºC

Time Seconds

NC

AgPdPt

60/40

260 ± 5

15 max

NB

Nickel Barrier

60/40

260 ± 5

30 ± 1

Case

P/N

D1

D2D3

D4D5

Size

0402

NB23

1.70

0.60

0.50

0.60

0.50

(.067)

(.024)

(.020)

(.024)

(.020)

0603

NB21

2.30

0.80

0.70

0.80

0.75

(.091)

(.031)

(.028)

(0.31)

(.030)

0805

NB12

3.00

1.00

1.00

1.00

1.25

(.118)

(.039)

(.039)

(.039)

(.049)

1206

NB20

4.00

1.00

2.00

1.00

2.50

(.157)

(.039)

(.079)

(.039)

(.098)

Case

P/N

D1

D2D3

D4D5

Size

0603

NB21

3.10

1.20

0.70

1.20

0.75

(.122)

(.047)

(.028)

(.047)

(.030)

0805

NB12

4.00

1.50

1.00

1.50

1.25

(.157)

(.059)

(.039)

(.059)

(.049)

1206

NB20

5.00

1.50

2.00

1.50

1.60

(.197)

(.059)

(.079)

(.059)

(.063)

Reflow

300

250

200

150

100

50

0

10 sec. max

1min

1min

(Minimize soldering time)

Natural

Cooling

220ºC

to

250ºC

Preheat

a) The visual standards used for evaluation of solder joints

will need to be modified as lead free joints are not as bright

as with tin-lead pastes and the fillet may not be as large.

b) Resin color may darken slightly due to the increase in

temperature required for the new pastes.

c) Lead-free solder pastes do not allow the same self align-

ment as lead containing systems. Standard mounting

pads are acceptable, but machine set up may need to be

modified.

300

250

200

150

100

50

0

0

50

100

150

200

250

300

• Pre-heating: 150°C ±15°C / 60-90s

• Max. Peak Gradient: 2.5°C/s

• Peak Temperature: 245°C ±5°C

• Time at >230°C: 40s Max.

Time (s)

Wave

300

250

200

150

100

50

0

3 sec. max

1 to 2 min

(Preheat chips before soldering)

T/maximum 150°C

Preheat

Natural

Cooling

230ºC

to

250ºC

T

D1

D2

D3

D4

D5

RECOMMENDED

SOLDERING PAD

LAYOUT

Dimensions in

mm (inches)