SJM Series

SJM Series

Due to steep rise of metal costs, examination of low silver Pb free solder is on the rise. Low silver SAC alloys have not been adapted to SMT assembly so far. Our SJM Solder especially improves thermal fatigue.

The Almit SJM Series is our lead free solder with improved thermal exhaustion resistance. The SJM products (available in solder paste and core solder) has extremely high heat-resistant fatigue properties. Especially when the soldered product is exposed to a strongly temperature changing environment, you won’t find any cracks or fatigue fracture.

These properties can be observed by a thermal shock test with a 1210 R Chip. We changed the temperature of the environment between -40°C and +125°C every 30 minutes. Our low silver SJM solder SJM-03 didn’t had any crack after 1000 cycles of temperature changing, while the standard SAC305 solder had huge cracks and fatigue fracture.

SJM-03

SJM-03-1000-05
SJM-03-1000-02

1000 cycles from -40°C to +125°C

SAC305-1000-01 SJM-03-1000-04
SJM-03-1000-03

SAC305

SAC305-1000-05
SAC305-1000-02

1000 cycles from -40°C to +125°C

SAC305-1500-01 SAC305-1000-04
SAC305-1000-03

Another 500 cycles more, and the SAC305 product is nearly cracked completely while the SJM solder doesn’t have any crack at all after a total of 1500 clycles

SJM-03

SJM-03-1500-05
SJM-03-1500-02

1500 cycles from -40°C to +125°C

SJM-03-1500-01 SJM-03-1500-04
SJM-03-1500-03

SAC305

SAC305-1500-05
SAC305-1500-02

1500 cycles from -40°C to +125°C

SJM-03-1000-01 SAC305-1500-04
SAC305-1500-03

Our high strength lead-free composition SJM-40 with bismut and antimony is even more powerful while our thermal shock test. Even after 2000 cylces of temperature changing, the SJM solder doesn’t show any crack while the SAC305 solder shows a complete subsidiary fracture.

SJM-40
 
1500 cyclesSJM-40-2000-03
SJM-40-2000-04
2000 cyclesSAC305-1500-4
SAC305-1500-5
 
SAC305
 
1500 cyclesSJM-40-2000-01
SJM-40-2000-02
 
2000 cyclesSAC305-1500-1
SAC305-1500-3 SAC305-1500-2