ERT-J1VP473H Datasheet, PDF (12/14 Pages) Panasonic Semiconductor – NTC Thermistors

(1) To minimize mechanical stress caused by the
warp or bending of a PC board, please follow
the recommended Thermistors’ layout below.
Prohibited layout
Recommended layout
Layout the Thermistors sideways
against the stressing direction
(2) The following layout is for your reference since
mechanical stress near the dividing/breaking
position of a PC board varies depending on the
mounting position of the Thermistors.
Perforation
E
D
C
A
B
Slit
Magnitude of stress A>B=C>D>E
(3) The magnitude of mechanical stress applied to
the Thermistors when the circuit board is divided
is in the order of push back < slit < V-groove <
perforation.
Also take into account the layout of the Thermistors
and the dividing/breaking method.
(4) When the Thermistors are placed near heating
elements such as heater, etc., cracks from thermal
stresses may be caused by the following:
·Soldering the Thermistors directly heating
elements.
·Mounting the Thermistors on the same land
that another Thermistor is mounted on.
For the above-mentioned mounting and/or
placement, please contact us in advance,
2.5 Mounting Density and Spaces
If components are arranged in too narrow a space,
the components can be affected by solder bridges
and solder balls. The space between components
should be carefully determined.
■ Precautions for Assembly
1. Storage
(1) The Thermistors shall be stored between 5 - 40 °C
and 20 - 70 % RH, not under severe conditions of
high temperature and humidity.
(2) If stored in a place that is humid, dusty, or contains
corrosive gasses (hydrogen sulfide, sulfurous
acid, hydrogen chloride and ammonia etc.), the
solderability of terminal electrodes may deteriorate.
In addition, storage in a place subjected to heating
and/or exposure to direct sunlight will cause
deformed tapes and reels, and component sticking
to tapes, both of which can result in mounting
problems
(3) Do not store components longer than 6 months.
Check the solderability of products that have
been stored for more than 6 months before use
Multilayer NTC Thermistors
2. Chip Mounting Consideration
(1) When mounting the Thermistors/components on
a PC board, the Thermistor bodies shall be free
from excessive impact loads such as mechanical
impact or stress due to the positioning, pushing
force and displacement of vacuum nozzles during
mounting.
(2) Maintenance and inspection of the Chip Mounter
must be performed regularly.
(3) If the bottom dead center of the vacuum nozzle is
too low, the Thermistor will crack from excessive
force during mounting.
The following precautions and recommendations are
for your reference in use.
(a) Set and adjust the bottom dead center of the
vacuum nozzles to the upper surface of the PC
board after correcting the warp of the PC board.
(b) Set the pushing force of the vacuum nozzle
during mounting to 1 to 3 N in static load.
(c) F or double sur face m ounting, apply a
supporting pin on the rear surface of the PC
board to suppress the bending of the PC
board in order to minimize the impact of the
vacuum nozzles. Typical examples are shown
in the table below.
Item
Single surface
mouting
Prohibited mounting Recommended mounting
Crack
The supporting pin does not necessarily
have to be positioned beneath the
Thermistor.
Supporting
pin
Double surface
mounting
Separation of Solder Crack
Supporting
pin
(d) Adjust the vacuum nozzles so that their bottom
dead center during mounting is not too low.
(4) The closing dimensions of the positioning chucks
shall be controlled. Maintenance and replacement
of positioning chucks shall be performed regularly
to prevent chipping or cracking of the Thermistors
caused by mechanical impact during positioning
due to worn positioning chucks.
(5) Maximum stroke of the nozzle shall be adjusted
so that the maximum bending of PC board does
not exceed 0.5 mm at 90 mm span. The PC
board shall be supported by an adequate number
of supporting pins.
3. Selection of Soldering Flux
Soldering flux may seriously affect the performance
of the Thermistors. The following shall be confirmed
before use.
(1) The soldering flux should have a halogen based
content of 0.1 wt% (converted to chlorine) or below.
Do not use soldering flux with strong acid.
(2) When applying water-soluble soldering flux,
wash the Thermistors sufficiently because the
soldering flux residue on the surface of PC
boards may deteriorate the insulation resistance
on the Thermistors’ surface.
00 Sep. 2010