tmp1940cyaf TOSHIBA Semiconductor CORPORATION, tmp1940cyaf Datasheet - Page 30

• Manufacturer Part Number: tmp1940cyaf
• Description: 32-bit Tx System Risc Tx19 Family
• Manufacturer: TOSHIBA Semiconductor CORPORATION

3.4.2
3.5
3.5.1
(1) Apply voltage to the test jig only after inserting the device securely into it. When applying or
(2) Make sure that the voltage applied to the device is off before removing the device from the
(3) Make sure that no surge voltages from the measuring equipment are applied to the device.
(4) The chips housed in tape carrier packages (TCPs) are bare chips and are therefore exposed.
There are essentially two main types of semiconductor device package: lead insertion and surface
mount. During mounting on printed circuit boards, devices can become contaminated by flux or
damaged by thermal stress from the soldering process. With surface-mount devices in particular,
the most significant problem is thermal stress from solder reflow, when the entire package is
subjected to heat. This section describes a recommended temperature profile for each mounting
method, as well as general precautions which you should take when mounting devices on printed
circuit boards. Note, however, that even for devices with the same package type, the appropriate
mounting method varies according to the size of the chip and the size and shape of the lead
frame. Therefore, please consult the relevant technical datasheet and databook.
Semiconductor devices must undergo a process in which the leads are cut and formed before the
devices can be mounted on a printed circuit board. If undue stress is applied to the interior of a
device during this process, mechanical breakdown or performance degradation can result. This is
attributable primarily to differences between the stress on the device’s external leads and the
stress on the internal leads. If the relative difference is great enough, the device’s internal leads,
adhesive properties or sealant can be damaged. Observe these precautions during the lead-
forming process (this does not apply to surface-mount devices):
Mounting
Inspection Sequence
removing power, observe the relevant precautions, if any.
test jig. Otherwise, the device may undergo performance degradation or be destroyed.
During inspection take care not to crack the chip or cause any flaws in it.
Electrical contact may also cause a chip to become faulty. Therefore make sure that nothing
comes into electrical contact with the chip.
Lead forming
! Do not insert devices in the wrong orientation. Make sure that the positive
" When conducting any kind of evaluation, inspection or testing using AC
! Always wear protective glasses when cutting the leads of a device with
" Do not touch the tips of device leads. Because some types of device have
and negative electrodes of the power supply are correctly connected.
Otherwise, the rated maximum current or maximum power dissipation
may be exceeded and the device may break down or undergo performance
degradation, causing it to catch fire or explode, resulting in injury to the
user.
power with a peak voltage of 42.4 V or DC power exceeding 60 V, be sure
to connect the electrodes or probes of the testing equipment to the device
under test before powering it on. Connecting the electrodes or probes of
testing equipment to a device while it is powered on may result in electric
shock, causing injury.
clippers or a similar tool. If you do not, small bits of metal flying off the cut
ends may damage your eyes.
leads with pointed tips, you may prick your finger.
3 General Safety Precautions and Usage Considerations
16