AN815

Vishay Siliconix

Document Number: 71334

12-Dec-03

www.vishay.com

1

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

Copper Leadframe Version

Recommended Pad Pattern and Thermal Performance

INTRODUCTION

The new single 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 single-channel version.

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 basic

pad layout and dimensions. These pad patterns are sufficient

for the low to medium power applications for which this

package is intended. Increasing the drain pad pattern yields a

reduction in thermal resistance and is a preferred footprint.

The availability of four drain leads rather than the traditional

single drain lead allows a better thermal path from the package

to the PCB and external environment.

PIN-OUT

Figure 1 shows the pin-out description and Pin 1

identification.The pin-out of this device allows the use of four

pins as drain leads, which helps to reduce on-resistance and

junction-to-ambient thermal resistance.

FIGURE 1.

SOT-363

SC-70 (6-LEADS)

6

4

1

2

3

5

Top View

D

D

G

D

D

S

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

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

EVALUATION BOARDS

SINGLE SC70-6

The evaluation board (EVB) measures 0.6 inches by

0.5 inches. The copper pad traces are the same as in Figure 2.

The board allows examination from the outer pins to 6-pin DIP

connections, permitting test sockets to be used in evaluation

testing. See Figure 3.

FIGURE 2.

SC-70 (6 leads) Single

52 (mil)

96 (mil)

13 (mil)

71 (mil)

0, 0 (mil)

18 (mil)

16 (mil)

26 (mil)

26 (mil)

654

3

2

1

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

measured on the EVB, comparing both the copper and

Alloy 42 leadframes. This test was first conducted on the

traditional Alloy 42 leadframe and was then repeated using the