Bonding of power devices is experiencing a rapid transition to aluminum ribbon for many reasons. Better electrical characteristics, improved heat dissipation, fewer bonds, improved throughput and increased reliability are some of the most obvious advantages.
Coining offers SPM Power Bond Ribbon™, a high purity corrosion resistant aluminum bonding ribbon, to meet this demand.
Using SPM Power Bond Ribbon™ eliminates the need for multiple wire bonds. The current required with two, three and even four bonds to the same device can now be attained with the properly selected ribbon. To determine the ribbon size needed, use this formula:
| (T) x (W) = (N) x (D˛) x (0.785), where |
T = thickness of ribbon |
| |
W = width of ribbon |
| |
N = number of wire bonds |
| |
D = diameter of wire |
Select a width and the required thickness can be determined.
Equivalent Number of Wires to Ribbon Conversion
|
Ribbon |
Wire Diameter (mils) |
|
Size (mils) |
5 |
8 |
10 |
12 |
15 |
20 |
|
30 x 3 |
4.6 |
1.8 |
1.2 |
|
|
|
|
40 x 4 |
8.2 |
3.2 |
2.0 |
1.4 |
|
|
|
50 x 5 |
12.7 |
5.0 |
3.2 |
2.2 |
1.4 |
|
|
40 x 6 |
12.2 |
4.8 |
3.1 |
2.1 |
1.4 |
|
|
60 x 6 |
18.3 |
7.2 |
4.6 |
3.2 |
2.0 |
1.2 |
|
80 x 6 |
24.4 |
9.6 |
6.1 |
4.2 |
2.7 |
1.5 |
|
50 x 8 |
20.4 |
8.0 |
5.1 |
3.5 |
2.3 |
1.3 |
|
60 x 8 |
24.4 |
9.6 |
6.1 |
4.2 |
2.7 |
1.5 |
|
80 x 8 |
32.6 |
12.7 |
8.2 |
5.7 |
3.6 |
2.0 |
|
60 x 10 |
30.6 |
11.9 |
7.6 |
5.3 |
3.4 |
1.9 |
|
80 x 10 |
40.7 |
15.9 |
10.2 |
7.1 |
4.5 |
2.6 |
Note: There are five standard widths of ribbon. They are: 0.030 inch, 0.040 inch, 0.050 inch, 0.060 inch and 0.080 inch. Other widths can be made available for specific applications.
Mechanical Properties
|
Size (inch) |
Tensile Strength (g) |
% Elongation |
Length/41R Spool |
|
0.030 x 0.003 |
250 – 350 |
15 – 25 |
125 MTRS |
|
0.040 x 0.004 |
500 – 750 |
20 – 25 |
90 MTRS |
|
0.050 x 0.005 |
1000 – 1500 |
20 – 35 |
80 MTRS |
|
0.040 x 0.006 |
700 – 1100 |
20 – 35 |
70 MTRS |
|
0.060 x 0.006 |
1300 – 1700 |
20 – 35 |
70 MTRS |
|
0.080 x 0.006 |
1800 – 2200 |
20 – 35 |
70 MTRS |
|
0.050 x 0.008 |
1200 – 1600 |
20 – 35 |
55 MTRS |
|
0.060 x 0.008 |
2000 – 2500 |
20 – 35 |
55 MTRS |
|
0.080 x 0.008 |
2300 – 2800 |
20 – 35 |
55 MTRS |
|
0.060 x 0.010 |
2200 – 2600 |
25 – 40 |
38 MTRS |
|
0.080 x 0 010 |
2700 – 3400 |
25 – 40 |
38 MTRS |
Spooling
Coining has specifically designed spools for SPM Power Bond Ribbon™. The spool type is designated as 41R and is a foil feed type of spool slightly wider than the ribbon width. The 41R spool is fully compatible with all bonding machines configured for standard 41B heavy wire spools. The use of this spool eliminated the chance of the ribbon underwinding and potential despoiling issues. | 
