AN816

Vishay Siliconix

Document Number: 71405

12-Dec-03

www.vishay.com

1

Dual-Channel LITTLE FOOTR 6-Pin SC-70 MOSFET

Copper Leadframe Version

Recommended Pad Pattern and Thermal Performance

INTRODUCTION

The new dual 6-pin SC-70 package with a copper leadframe

enables improved on-resistance values and enhanced

thermal performance as compared to the existing 3-pin and

6-pin packages with Alloy 42 leadframes. These devices are

intended for small to medium load applications where a

miniaturized package is required. Devices in this package

come in a range of on-resistance values, in n-channel and

p-channel versions. This technical note discusses pin-outs,

package outlines, pad patterns, evaluation board layout, and

thermal performance for the dual-channel version.

PIN-OUT

Figure 1 shows the pin-out description and Pin 1 identification

for the dual-channel SC-70 device in the 6-pin configuration.

Both n-and p-channel devices are available in this package –

the drawing example below illustrates the p-channel device.

FIGURE 1.

SOT-363

SC-70 (6-LEADS)

6

4

1

2

3

5

Top View

For package dimensions see outline drawing SC-70 (6-Leads)

(http://www.vishay.com/doc?71154)

BASIC PAD PATTERNS

See Application Note 826, Recommended Minimum Pad

Patterns With Outline Drawing Access for Vishay Siliconix

MOSFETs, (http://www.vishay.com/doc?72286) for the SC-70

6-pin basic pad layout and dimensions. This pad pattern is

sufficient for the low-power applications for which this package

is intended. Increasing the drain pad pattern (Figure 2) yields

a reduction in thermal resistance and is a preferred footprint.

FIGURE 2.

SC-70 (6 leads) Dual

48 (mil)

16 (mil)

65

4

3

2

1

61 (mil)

26 (mil)

8 (mil)

0.0 (mil)

23 (mil)

71 (mil)

96 (mil)

26 (mil)

87 (mil)

EVALUATION BOARD FOR THE DUAL-

CHANNEL SC70-6

The 6-pin SC-70 evaluation board (EVB) shown in Figure 3

measures 0.6 in. by 0.5 in. The copper pad traces are the same

as described in the previous section, Basic Pad Patterns. The

board allows for examination from the outer pins to the 6-pin

DIP connections, permitting test sockets to be used in

evaluation testing.

The thermal performance of the dual 6-pin SC-70 has been

measured on the EVB, comparing both the copper and Alloy

PCB with dual-side copper coating.

A helpful way of displaying the thermal performance of the

6-pin SC-70 dual copper leadframe is to compare it to the

traditional Alloy 42 version.