Electrical properties of printed wiring boards. [Electrical properties of Sandia/Bendix Standard Process printed wiring boards]
Results of a series of tests to establish electrical parameters for Sandia/Bendix Standard Process printed wiring boards are described. Test results are displayed graphically and tabulated for use by sub-system designers. The results include voltage holdoff, current carrying capacity and insulation resistance for double sided bare, coated and encapsulated boards. The boards were fabricated by a panel plating process and contain variable conductor widths and separations. Breakdown voltage in room environment did not occur below 1 kV for any spacing on a board. Average breakdown voltage in kV followed the relationship, V = 3.1 S/sup 0/./sup 51/, where separation S ranged from 0.25 to 1.5 mm. Parylene or urethane coated, urethane foamed, and glass microballoon filled epoxy encapsulated boards had higher breakdown voltages than bare boards. At low pressure, 660 Pa (5 torr), breakdowns which ranged from 0.4 to 25 kV were not a function of conductor separation. Low pressure breakdown voltage was generally higher for coated or encapsulated boards although the difference was not nearly as great as for room conditions. Current carrying capability of conductors was evaluated from the temperature rise generated with step increases in current. Variations in temperature rise between conductors with the same nominal or design width were correlated with measured differences in conductor cross sectional areas. Resistances calculated from conductor lengths and cross sectional areas were within 10 percent of the measured values. At normal operating temperatures, coated and encapsulated boards were similar in current carrying capacity to bare boards. At currents which caused conductors on bare boards to rapidly burn through, encapsulated conductors increased slowly in temperature until the encapsulation degraded and ruptured. Insulation resistance for all boards ranged from 1 to 230 teraohms at 10 to 30 percent RH. At 92 to 100 percent RH resistance was 1 to 4 decades lower.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- DOE Contract Number:
- AT(29-1)789
- OSTI ID:
- 7361495
- Report Number(s):
- SAND-75-0663
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dimensional and electrical characteristics of printed boards made with Multipurpose Test Pattern, B-25
Effect of high-moisture environments on printed-wiring-board insulation