Engineering topics
Publications and source records attributed to Buggle, R. N..
Hidden defects revealed if X-ray energy decreased as exposure progresses. Declining-potential X-ray photography detects fractures in thin metal sheet covered by unbroken sheet of twice thickness. Originally developed to check solder connections on multilayer circuit boards, technique has potential for other nondestructive testing.
Instrument reads tip temperature and contact potential in seconds. Tinned soldering tip touched to temperature sensitive button for 4 seconds and to voltage probe for 1 to 3 seconds. Tip temperature and voltage appear on digital displays. Instrument quickly gives assurance conditions are correct for reliable soldering.
Background noise reduced by some special precautions. Blanket of argon flows over solution so no chance for contamination from air to creep in. Conventional pump replaced with one made of polytetrafluoroethlylene component and all metal couplings eliminated from flow lines. Used to improve quality control in integrated circuit fabrication, lens fabrication, and vacuum-tube assembly.
Simple apparatus checks insulation between plastic and metal surfaces. Film can be inspected more accurately; apparatus can spot minute electrical contaminants between plastic and metal films. Steel roller connected to high-range ohmmeter is guided over entire plastic area of test sample. Roller weighs 2 lb. (0.9 kg), which effectively translates into 250-psi (1.76X10 to 6th power -N/sq m) contact pressure at plastic surface sufficient to locate microscopic defects.