DTA114EET1 SERIES

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8

MINIMUM RECOMMENDED FOOTPRINTS FOR SURFACE MOUNTED APPLICATIONS

Surface mount board layout is a critical portion of the

total design. The footprint for the semiconductor packages

must be the correct size to insure proper solder connection

interface between the board and the package. With the

correct pad geometry, the packages will self align when

subjected to a solder reflow process.

1.4

0.5 min. (3x)

TYPICAL

SOLDERING PATTERN

Unit: mm

SOT–416/SC–75 POWER DISSIPATION

The power dissipation of the SOT–416/SC–75 is a

function of the pad size. This can vary from the minimum

pad size for soldering to the pad size given for maximum

power dissipation. Power dissipation for a surface mount

resistance from the device junction to ambient; and the

The values for the equation are found in the maximum

ratings table on the data sheet. Substituting these values

one can calculate the power dissipation of the device which

in this case is 200 milliwatts.

150

°C – 25°C

= 200 milliwatts

600

°C/W

The 600

°C/W assumes the use of the recommended

footprint on a glass epoxy printed circuit board to achieve a

power dissipation of 200 milliwatts. Another alternative

would be to use a ceramic substrate or an aluminum core

board such as Thermal Clad

™. Using a board material such

as Thermal Clad, a higher power dissipation can be

achieved using the same footprint.

SOLDERING PRECAUTIONS

The melting temperature of solder is higher than the rated

temperature of the device. When the entire device is heated

to a high temperature, failure to complete soldering within

a short time could result in device failure. Therefore, the

following items should always be observed in order to

minimize the thermal stress to which the devices are

subjected.

• Always preheat the device.

• The delta temperature between the preheat and

soldering should be 100

°C or less.*

• When preheating and soldering, the temperature of the

leads and the case must not exceed the maximum

temperature ratings as shown on the data sheet. When

using infrared heating with the reflow soldering

method, the difference should be a maximum of 10

°C.

• The soldering temperature and time should not exceed

260

°C for more than 10 seconds.

• When shifting from preheating to soldering, the

maximum temperature gradient should be 5

°C or less.

• After soldering has been completed, the device should

be allowed to cool naturally for at least three minutes.

Gradual cooling should be used as the use of forced

cooling will increase the temperature gradient and

result in latent failure due to mechanical stress.

• Mechanical stress or shock should not be applied

during cooling.

* Soldering a device without preheating can cause

excessive thermal shock and stress which can result in

damage to the device.