Solder Powder Sizes

Suspended Solder Powder in flux

Alloy Table

Here is a standard alloy table for solder alloys. There is an extra column. In this column there is an alloy density. The density of fluxes varies, but 1 g / cm 3 is a good guess. This data allows us to see a couple of things:

  1. Dispensing is more about the physical volumes than the weights.  Solder paste is specified as it is mixed during manufacturing - by weight.  So a solder paste at 86% (pretty normal) metal content is 85% by weight, as the alloys change so do the volumes. Using a 63/37 alloy the volume is about 41%
  2. When switching between alloys (like changing from a leaded 63/37 to a no lead solder (SAC305 -Sn96.5Ag3.0Cu0.5) the volumes change significantly from 41%  to 45%
  3. Soft metals coin more easily

 

 

ALLOY

Paste at 86% metal Loading

Metal Density

Flux Density

Volume of metal

Sn63Pb37

7.74

8.84

1.00

41%

Sn60Pb40

7.84

8.96

1.00

41%

Sn55Pb45

8.01

9.15

1.00

40%

Sn50Pb50

8.18

9.35

1.00

40%

Sn45Pb55

8.35

9.55

1.00

39%

Sn40Pb60

8.53

9.75

1.00

39%

Sn35Pb65

8.70

9.95

1.00

38%

Sn30Pb70

8.87

10.15

1.00

38%

Sn25Pb75

9.04

10.35

1.00

37%

Sn20Pb80

9.21

10.55

1.00

37%

Sn10Pb90

9.55

10.94

1.00

36%

Sn05Pb95

9.72

11.14

1.00

36%

LEAD-FREE

 

Metal Density

Flux Density

Volume of metal

Sn96.5Ag3.5

6.76

7.70

1.00

44%

Sn96Ag04

6.58

7.49

1.00

45%

Sn95Ag05

6.61

7.52

1.00

45%

100%Sn

6.47

7.37

1.00

45%

Sn95Sb05

6.45

7.33

1.00

46%

Sn99.3Cu0.7

6.48

7.38

1.00

45%

Sn96.6Ag3.0Cu0.5

6.57

7.47

1.00

45%

Sn95.5Ag3.8Cu0.7

6.59

7.49

1.00

45%

BISMUTH ALLOYS

 

Metal Density

Flux Density

Volume of metal

Sn 42 / Bi 58

2.80

3.09

1.00

67%

OTHER ALLOYS

 

Metal Density

Flux Density

Volume of metal

Sn62Pb36Ag02

7.76

8.86

1.00

41%

Sn60Pb36Ag04

7.81

8.92

1.00

41%

Sn10Pb88Ag02

9.54

10.93

1.00

36%

Sn05Pb93.5Ag1.5

9.61

11.02

1.00

36%

Sn05Pb92.5Ag2.5

9.61

11.02

1.00

36%

Sn43Pb43Bi14

8.46

9.67

1.00

39%