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

(2) Excessive cleaning can lead to:
(a) Overuse of ultrasonic cleaning may deteriorate
the strength of the terminal electrodes or cause
cracking in the solder and /or ceramic bodies of
the Thermistors due to vibration of the PC boards.
Please follow these conditions for Ultrasonic
cleaning:
Ultrasonic wave output
: 20 W/L max.
Ultrasonic wave frequency : 40 kHz max.
Ultrasonic wave cleaning time : 5 min. max.
5.3 Contamination of Cleaning solvent
Cleaning with contaminated cleaning solvent may
cause the same results as insufficient cleaning due
to the high density of liberated halogen.
6.Inspection Process
When mounted PC boards are inspected with
measuring terminal pins, abnormal and excess
mechanical stress shall not be applied to the PC
board or mounted components, to prevent failure
or damage to the devices.
(1) Mounted PC boards shall be supported by
an adequate number of supporting pins with
bend settings of 90 mm span 0.5 mm max.
(2) Confirm that the measuring pins have the right
tip shape, are equal in height and are set in the
correct positions.
The following figures are for your reference to
avoid bending the PC board.
Item
Bending of
PC board
Prohibited setting
Recommended
setting
Check pin
Check pin
Separated, Crack
Supporting pin
7. Protective Coating
When the surface of a PC board on which the
Capacitors have been mounted is coated with resin
to protect against moisture and dust, it shall be
confirmed that the protective coating which is
corrosive or chemically active is not used, in order
that the reliability of the Thermistors in the actual
equipment may not be influenced. Coating materials
that expand or shrink also may lead to damage to
the Thermistors during the curing process.
8. Dividing/Breaking of PC Boards
(1) Abnormal and excessive mechanical stress such
as bending or torsion shown below can cause
cracking in the Thermistors.
Bending
Torsion
Multilayer NTC Thermistors
(3) Examples of PCB dividing/breaking jigs:
The outline of PC board breaking jig is shown
below. When PC boards are broken or divided,
loading points should be close to the jig to
minimize the extent of the bending
Also, planes with no parts mounted on should
be used as plane of loading, which generates
a compressive stress on the mounted plane,
in order to prevent tensile stress induced by the
bending, which may cause cracks of the Thermistors
or other parts mounted on the PC boards.
Outline of Jig
PC board
V-groove
PC board
splitting jig
Prohibited dividing
Recommended dividing
Loading
point
PC
board
Loading direction
Chip
component
V-groove
PC
board
Loading direction
V-groove
Chip component
Loading
point
9. Mechanical Impact
(1) The Thermistors shall be free from any excessive
mechanical impact.
The Thermistor body is made of ceramics and
may be damaged or cracked if dropped.
Never use a Thermistor which has been
dropped; their quality may be impaired and
failure rate increased.
(2) When handling PC boards with Thermistors
mounted on them, do not allow the Thermistors
to collide with another PC board.
When mounted PC boards are handled or stored
in a stacked state, impact between the corner
of a PC board and the Thermistor may cause
damage or cracking and can deteriorate the
withstand voltage and insulation resistance of the
Thermistor.
Mounted PCB
Crack
Floor
Crack
(2) Dividing/Breaking of the PC boards shall be
done carefully at moderate speed by using a jig
or apparatus to prevent the Thermistors on the
boards from mechanical damage.
■ Other
The various precautions described above are typical.
For special mounting conditions, please contact us.
00 Sep. 2010