Table 1 Comparison of the radiopurity of copper-polyimide laminates. The (xN) factor in the fourth row indicates whether the copper was on one or both sides of the laminate
Type | Vendor | Polyimide thickness [μm] | Copper thickness [μm] | 238U [pg/g] | 232Th [pg/g] | natK [ng/g] |
|---|---|---|---|---|---|---|
Taiflex 2FPDR2005JA | Taiflex | 50.8 | 18 (x2) | 8 ± 6 | 9 ± 4 | <100 |
300ELJ+Cu laminate [15] | DuPont R&D | 76.2 | 18 (x2) | 8.6 ± 3.6 | 20 ± 14 | 164 ± 82 |
Pyralux AP8535R [15] | DuPont | 76.2 | 18 (x2) | 158.0 ± 6.1 | 24.1 ± 0.9 | <210 |
Novaclad 146319-009 [15] | Sheldahl | 50.8 | 5.0 (x1) | 283 ± 21 | 50.1 ± 3.9 | <210 |
Cirlex [15] | Fralock | 228.6 | 34 (x2) | 413 ± 45 | 71.4 ± 2.1 | <210 |
Espanex MC15-40-00VEG [20] | Nippon Steel | 40 | 15 (x1) | 121 ± 32 | <250 | 880 ± 120 |
Espanex MC18-25-00CEM [20] | Nippon Steel | 25 | 18 (x1) | <46 | <260 | <146 |
Espanex SB [14] | Nippon Steel | 25 | 18 (x2) | <284 | <812 | <1777 |