Datasheet

6© KEMET Electronics Corporation • KEMET Tower • One East Broward Boulevard F3087_P278_X1_480 • 2/20/2019
Fort Lauderdale, FL 33301 USA • 954-766-2800 • www.kemet.com
Film Capacitors – AC Line EMI Suppression and RC Networks
P278, Metallized Impregnated Paper, Class X1, 480 VAC
Soldering Process
The implementation of the RoHS Directive has required the selection of SnAuCu (SAC) alloys or SnCu alloys as primary solder.
Thishasincreasedtheliquidustemperaturefrom183°CforSnPbeutecticalloysto217–221°Cforthenewalloys.Asaresult,
the heat stress to components, even in wave soldering, has increased considerably due to higher pre-heat and wave temperatures.
Polypropylenecapacitorsareespeciallysensitivetoheat(themeltingpointofpolypropyleneis160–170°C).Wavesolderingcan
be destructive, especially for mechanically small polypropylene capacitors (lead spacings 5 – 10 mm). Great care must be taken
duringsoldering.ThesolderprolesfromKEMETarehighlyrecommended.Youmayalsorefertothewavesolderingcurvefrom
IEC Publication 61760-1 Edition 2. Consult KEMET with any questions.
Figure 1
Wave Soldering Recommendations
0
50
100
150
200
250
300
0
40
80
120
160
200
240
Temperature (°C)
Time (s)
ca 2°C/second
ca 3.5°C/second typical
ca 5°C/second
Cooling
2 +3 seconds maximum
115 °C max
T
preheat
∆T < 150°C
100 °C
Preheating
Typical
First wave
Second wave
260°C