Example of temperature profile of lead (Pb) solder
(°C)
240
210
150
Package surface
temperature
60 to 90 seconds 30 seconds or less Time
Example of temperature profile of lead (Pb)-free solder
(°C)
260
230
180
190
Package surface
temperature
60 to 120 seconds 30 to 50 seconds Time
Board Assembly Considerations
1. Soldering 2. Flux Cleaning
When using a soldering iron or medium infrared ray/hot air reflow,
avoid a rise in device temperature as much as possible by
observing the following conditions.
1.1) Using a soldering iron
a. Solder once within 10 seconds for a lead temperature of
up to 260°C.
b. Solder once within 3 seconds for a lead temperature of up
to 350°C.
1.2) Using medium infrared ray/hot air reflow
a. Complete the infrared ray/hot air reflow process at once
within 30 seconds at a package surface temperature
between 210°C and 240°C.
b. Example of temperature profile of lead (Pb) solder
●When cleaning circuit boards to remove flux, make sure that
no residual reactive ions such as sodium(Na+) or chloride(Cl–)
ions remain. Note that organic solvents react with water to
generate hydrogen chloride and other corrosive gases, which
can degrade device performance.
●Washing devices with water will not cause any problems.
However, make sure that no reactive ions such as
sodium(Na+) or chloride(Cl–) ions are left as residue. Also, be
sure to dry devices sufficiently after washing.
●Do not rub device markings with a brush or with your hand
during cleaning or while the devices are still wet from the
cleaning agent. Doing so can rub off the markings.
●Dip cleaning, shower cleaning and steam cleaning processes
all involve the chemical action of a solvent. Use only
recommended solvents for these cleaning methods. When
immersing devices in a solvent or steam bath, make sure
that the temperature of the liquid is 50°C or below and that
the circuit board is removed from the bath within one minute.
●If a device package allows ultrasonic cleaning, keep the
duration of ultrasonic cleaning as short as possible, since
long hours of ultrasonic cleaning degrade the adhesion
between the mold resin and the frame material.
Suspend the circuit board in the solvent bath during ultrasonic
cleaning in such a way that the ultrasonic vibrator does not come
into direct contact with the circuit board or the device.
Conventional cleaning solvents that contain freon are not
recommended due to its adverse effection the earth’s ozone layer.
Alternative freon-free products are available on the market. Some
of these alternative cleaning agents are listed in the table below.
Contact Toshiba or a Toshiba distributor regarding cleaning
conditions and other relevant information for each product type.
1.3)Dip soldering (flow soldering)
Keeping packages at high temperature for a long period of
time can degrade the quality and reliability of devices.
Soldering time has to be kept as short as possible to
avoid a rise in package temperature.
When using a halogen lamp or infrared heater, avoid
direct irradiation of packages, since this may cause a rise
in package temperature.
The thermal shock of dip soldering increases thermal stress
on devices. To avoid stress, the use of a soldering iron or
medium infrared ray/hot air reflow is recommended. If you
want to use dip soldering, contact your nearest Toshiba
sales representative.
d. Precautions for heating
The profile below shows only the typical temperature profile
and conditions, which might not apply to all Toshiba
photocouplers. Temperature profiles and conditions may
differ from product to product. Refer to the relevant technical
datasheets and databooks when mounting a device.
■ The following ultrasonic cleaning conditions
are recommended.
Frequency: 27 kHz to 29 kHz
Ultrasonic output power: 300 W or less (0.25 W/cm2 or less)
Cleaning time: 30 seconds or less
Examples of Alternative Cleaning Agents
Technocare GE Toshiba Silicon
Asahi Clean Asahi Glass Co., Ltd
Clean Through
AK-225AES
750H Kao Co., Ltd.
Pine Alpha Arakawa Chemical Co., Ltd.
FRW-1, FRW-17,
FRV-100
ST-100S,
ST-100SX
c. Example of temperature profile of lead (Pb)-free solder
2
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