Copper Dissolution

With the arrival of high tin solder alloys for lead-free soldering, the challenge of copper dissolution has arisen.  Copper dissolution, or the reduction in copper thickness, occurs during hot air solder leveling (HASL) or soldering at high temperatures for extended periods.  Alpha’s tin-copper solders are supplemented with additives that specifically reduce copper dissolution.

The copper dissolution process is temperature and solder alloy dependent The solubility of copper in the new lead free alloys with tin compositions of at least 95% tin is potentially higher than that of tin-lead solder. Alpha has recognized the potential reliability problems associated with this defect and engineered a series of Pb-free alloys that minimize Copper Dissolution thereby improving the reliability of each solder joint formed.


Alpha products that reduce Copper Dissolution:

Alpha Bar Solder Alloys

Use the chart below to determine which Alpha alloy is right for you. Simply align the type of assembly being made with the appropriate alloy.

 Assembly Type
Simple, single sided, FR2 / CEM-1 laminates
Dual sided FR-4 w/ PTH's, 1.6mm thick, up to 4 inner copper layers, metallized pad finishes
Complex, up to 12 inner copper layers, OSP pad finishes, all processing in air
>2.4mm thick, >12 inner copper layers, large high heat capacity components
 SACX Plus 0807

 SAC alloys label for table
  1%+ flux solids, L0, pin testable
Flux Type
  SACX Plus 0307
    4%+ flux solids, L or M0, pin testable
 SnCX Plus™ 07
          4%+ flux solids, L or M0, moderately pin testable
            7%+ flux solids, L,M or H1, not pin testable
0ºC to 100ºC - standard profile cycles
0ºC to 100ºC - standard and shock profile cycles
- 25ºC to 125ºC - standard and shock profile cycles
- 45ºC to 125ºC - standard and shock profile cycles
Thermal Fatigue Resistance



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