sReference Data

Thermal resistance vs. Copper area

Power dissipation vs. Copper area

sExample of Solder Pattern Design

Symbol

Dimensions (mm)

e1

5.72

e

1.27

±0.15

α

0.2

β1

0.2 to 0.5

β2

0.2

L

0.6

b2

0.76

l2

L+

β1+β2

*1 The inner frame stage on which a monolithic IC is mounted is

directly connected to the GND pins (pins 5 through 8). By

expanding the area of the copper connected to the GND pins,

the heat radiation can be improved. It is recommended to

design the solder pattern by opening the insulation film of the

solder patterns of pins 5, 6, 7, and 8, on the wide GND

pattern as shown in Figure 1.

(Reference value conforming to EIAJ

Standard ED-7402-1)

• Calculating junction temperature

Measure the temperature TL of the lead of the GND pin (pin 7) by using a thermocouple, and substitute the

measured value into the following expression to calculate the junction temperature.

(

qSI-3000KS Series

L

e

L

L

α

e

e1

b

e

ee

e

e1

l2

b2

*1

Figure 1

ee

e

8

GND pattern

1

7

2

6

3

5

b2

e1

l2

4

10

100

140

120

100

80

60

40

1000

Area of PC board : 40

×40mm

10

100

1.2

1

0.8

0.6

0.4

0.2

0

1000

Tj=100

°C Area of PC board : 40×40mm

Ta=25

°C

Ta=50

°C

Ta=80

°C