tmp1941af TOSHIBA Semiconductor CORPORATION, tmp1941af Datasheet - Page 33

• Manufacturer Part Number: tmp1941af
• Description: 32-bit Tx System Risc
• Manufacturer: TOSHIBA Semiconductor CORPORATION

3.5.8
3.5.9
3.5.10
3.5.11
When devices are to be used in equipment requiring a high degree of reliability or in extreme
environments (where moisture, corrosive gas or dust is present), circuit boards may be coated for
protection. However, before doing so, you must carefully consider the possible stress and
contamination effects that may result and then choose the coating resin which results in the
minimum level of stress to the device.
(1) When attaching a heat sink to a device, be careful not to apply excessive force to the device in
(2) When attaching a device to a heat sink by fixing it at two or more locations, evenly tighten
(3) Drill holes for screws in the heat sink exactly as specified. Smooth the
(4) A coating of silicone compound can be applied between the heat sink and
(5) If the device is housed in a plastic package, use caution when selecting the type of silicone
(6) Heat-sink-equipped devices can become very hot during operation. Do not touch them, or you
(1) Make sure the screws are tightened with fastening torques not exceeding the torque values
(2) Do not allow a power screwdriver (electrical or air-driven) to touch devices.
Do not remount or re-use devices which fall into the categories listed below; these devices may
cause significant problems relating to performance and reliability.
(1) Devices which have been removed from the board after soldering
(2) Devices which have been inserted in the wrong orientation or which have had reverse
(3) Devices which have undergone lead forming more than once
Tightening torque
Repeated device mounting and usage
Circuit board coating
Heat sinks
the process.
all the screws in stages (i.e. do not fully tighten one screw while the rest are still only loosely
tightened). Finally, fully tighten all the screws up to the specified torque.
surface by removing burrs and protrusions or indentations which might
interfere with the installation of any part of the device.
the device to improve heat conductivity. Be sure to apply the coating
thinly and evenly; do not use too much. Also, be sure to use a non-volatile
compound, as volatile compounds can crack after a time, causing the
heat radiation properties of the heat sink to deteriorate.
compound to be applied between the heat sink and the device. With some types, the base oil
separates and penetrates the plastic package, significantly reducing the useful life of the
device.
Two recommended silicone compounds in which base oil separation is not a problem are
YG6260 from Toshiba Silicone.
may sustain a burn.
stipulated in individual datasheets and databooks for the devices used.
current applied
3 General Safety Precautions and Usage Considerations
21