Precision Thin Film

Nichrome Chip Resistors

PCF Series

Wrap-around terminations provide good leach properties and ensure reliable contact. Due to the robust construction, the PCF can

be immersed in the solder bath for 30 seconds at 260°C. This enables the resistor to be mounted on one side of a printed circuit

board and wire-leaded components applied on the other side.

PCF resistors themselves can operate at a maximum temperature of 125°C (see performance above) (155°C for High Power grades).

For soldered resistors, the joint temperature should not exceed 110°C. This condition is met when the stated power levels at 70°C

are used.

Precision Surface Mount Resistors

03.11

© Welwyn Components Limited Bedlington Northumberland NE22 7AA, UK

Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info@welwyn-tt.com Website: www.welwyn-tt.com

PCF Series

Solderability

The terminations have an electroplated nickel barrier and tin coating. This ensures excellent 'leach' resistance properties and

solderability.

Packaging

PCF Resistors are supplied taped and reeled as as per IEC 286-3. Sizes 2010 and 2512 are in embossed plastic tape.

Application Notes

PCF resistors are ideally suited for handling by automatic methods due to their rectangular shape and the small dimensional

tolerances. Electrical connection to a ceramic substrate or to a printed circuit board can be made by reflow or wave soldering of

wrap-around terminations.

Derating Curve

Smaller sizes are in paper tape.

Precision Surface Mount Resistors

03.11

© Welwyn Components Limited Bedlington Northumberland NE22 7AA, UK

Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info@welwyn-tt.com Website: www.welwyn-tt.com

PCF Series

>0.05% tolerance

0603 to 2512

0.25%

0.3%

0.5%

0.25%

0.1%

0.2%

Load life

Humidity

Short term overload

High temperature operation

Temperature cycle

Resistance to solder heat

Solderability

Maximum change (+0.05R)

Chip size

0201, 0402

0.5%

0.3%

0.5%

0.25%

0.1%

0.2%

≤0.05% tolerance

0603 to 2512

0.05%

0.05%

0.05%

0.25%

0.05%

0.05%

Conditions

Test Parameters

1000 hours rated load @ 70°C

1000 hours @ 40°C, 90 - 95%RH

6.25 x rated Power , or 2 x LEV, for 5 sec

1000 hours at 125°C

5 cycles -55 C, 125°C

270°C, 10 sec

235°C, 2 sec

95% minimum coverage

0.5%

0.5%

0.5%

0.5%

0.25%

0.2%

95% minimum coverage

Load life

Humidity

Short term overload

High temperature operation

Temperature cycle

Resistance to solder heat

Solderability

Maximum change (+0.05R)

Conditions

Test Parameters

1000 hours rated load @ 70°C

1000hrs @ 40°C, 90 - 95%RH

6.25 x rated Power, or 2 x LEV, for 5 sec

1000 hours at 155°C

5 cycles -55°C, 150°C

270°C, 10 sec

235°C, 2 sec

0603 to 2512

0.05%

0.05%

0.02%

0.05%

0.02%

0.02%

Load life

Humidity

Short term overload

High temperature operation

Temperature cycle

Resistance to solder heat

Solderability

Maximum change (+0.05R)

Conditions

Test Parameters

1000 hours rated load @ 70°C

1000hrs @ 40°C, 90 - 95%RH

6.25 x rated Power, or 2 x LEV, for 5 sec

1000 hours at 125°C

5 cycles -55 C, 125°C

270°C, 10 sec

235°C, 2 sec

95% minimum coverage

0402

0.25%

0.5%

0.1%

0.5%

0.1%

0.1%

Performance Data - Standard Range

Performance Data - High Power Range/Extended High Power Range

Performance Data - Passivated Range

Construction

A thin-film material is selectively deposited on a 96% alumina substrate together with metallic contacts at each end of the resistor.

The unadjusted resistors are heat treated to give the required TCR and stability, then a precisely controlled laser trim process adjusts

the resistance value. Epoxy protection is applied and wrap-around terminations are added and plated with Nickel then Tin. Each

resistor is measured immediately before packing into tape.

Terminations

The standard termination is 100% Sn matte plated wrap-around suitable for soldering. SnPb plated option is available for standard

range PCF over the restricted range below.

Physical Data

Dimensions (mm) and Weight (mg)

L

W

T max

A

C

Wt

0201

0.58 0.05

0.29 0.05

0.26

0.15 0.05

0.12 0.05

0.14

0402

1.0 0.05

0.5 0.05

0.55

0.2 0.1

0.2 0.1

0.54

0603

1.6 0.2

0.8 0.2

0.65

0.3 0.2

0.3 0.2

1.8

0805

2.0 0.2

1.25 0.2

0.65

0.4 0.25

0.3 0.2

4.7

1206

3.05 0.15

1.55 0.15

0.65

0.35 0.25

0.42 0.2

9.0

1210

3.10 0.15

2.4 0.15

0.65

0.55 0.25

0.4 0.2

10

2010

4.9 0.2

2.4 0.2

0.65

0.5 0.25

0.6 0.3

24

2512

6.3 0.2

3.1 0.2

0.65

0.5 0.25

0.6 0.3

38

T

W

A

A

L

Wrap-around terminations

(3 faces)

C

0

100%

100%

70

100%

100%

125

35%

0%

155

0%

0%

20%

40%

60%

80%

100%

0

50

100

150

Ambient Temperature (°C)

Temperature Derating

High Power

Ranges

Standard &

Passivated

Derating Curve

12.16

General Note

TT Electronics reserves the right to make changes in product specification without notice or liability.

All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.

© TT Electronics plc

http://www.ttelectronics.com/resistors

BI Technologies IRC Welwyn