EZJPZV6R8GANIL Datasheet, PDF (11/13 Pages) Panasonic Semiconductor – Multilayer Varistors

Multilayer Varistors
(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 Varistors
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 0.5mm at 90 mm span. The PC board shall
be supported by an adequate number of supporting
pins.
4. Selection of Soldering Flux
Soldering flux may seriously affect the performance of
the Varistors. 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 Varistors sufficiently because the soldering flux
residue on the surface of PC boards may
deteriorate the insulation resistance on the
Varistors’ surface.
Recommended profile for Flow soldering [Ex.]
Soldering
260
Gradual cooling
240
(at ordinary temperature)
3~5 秒
60 to 120sec 3 to 5
Time
sec
<Allowable temperature difference>
Size
Temp. Tol.
0603
∆T 150°C
For products specified in individual
specifications, avoid flow soldering.
5.2 Reflow Soldering
The reflow soldering temperature conditions are each
temperature curves of Preheating, Temp. rise, Heating,
Peak and Gradual cooling.
Large temperature difference caused by rapid heat
application to the Varistors may lead to excessive
thermal stresses, contributing to the thermal cracks.
The Preheating temperature requires controlling with
great care so that tombstone phenomenon may be
prevented.
5. Soldering
5.1 Flow Soldering
For flow soldering, abnormal and large thermal and
mechanical stress, caused by the ” Temperature
Gradient” between the mounted Varistors and melted
solder in a soldering bath may be applied directly to
the Varistors, resulting in failure and damage of the
Varistors. Therefore it is essential that soldering
process follow these recommended conditions.
(1) Application of Soldering flux:
The soldering flux shall be applied to the mounted Varistors
thinly and uniformly by foaming method.
(2) Preheating:
The mounted Varistors/Components shall be pre-heated
sufficiently so that the “Temperature Gradient” between the
Varistors/Components and the melted solder shall be
150 °C max. (100 to 130°C)
(3) Immersion into Soldering bath:
The Varistors shall be immersed into a soldering bath of
240 to 260 °C for 3 to 5 seconds.
(4) Gradual Cooling:
The Varistors shall be cooled gradually to room ambient
temperature with the cooling temperature rates of 8 °C /s
max. from 250°C to 170 °C and 4 °C/s max. from 170 °C to
130°C.
(5) Flux Cleaning:
When the Varistors are immersed into a cleaning solvent,
be sure that the surface temperatures of devices do not
exceed 100 °C.
(6) Performing flow soldering once under the conditions shown
in the figure below [Recommended profile of Flow soldering
(Ex)] will not cause any problems. However, pay attention
to the possible warp and bending of the PC board.
Item
Preheating
Temp. rise
Heating
Peak
Gradual cooling
Temperature
140 to 180°C
Preheating temp
to Peak temp.
220°C min.
260°C max.
Peak temp.
to 140°C
Period or Speed
60 to 120 sec
2 to 5°C /sec
60 sec max.
10 sec max.
1 to 4°C /sec
Recommended profile of Reflow soldering (EX)
④Peak
260
②Temp.rise
220
⑤Gradual
cooling
180
140
①Preheating ③Heating
Time
60 to 120 sec 60 sec max.
∆T : Allowable temperature difference ∆T 150°C
The rapid cooling (forced cooling) during Gradual
cooling part should be avoided, because this may
cause defects such as the thermal cracks, etc.
When the Varistors are immersed into a cleaning
solvent, make sure that the surface temperatures of the
devices do not exceed 100 .
Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use.
Should a safety concern arise regarding this product, please be sure to contact us immediately.
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