Title :
Environmentally advantageous industrial processes based on pulsed power technology
Author :
Hartmann, W. ; Rohde, K.-D.
Author_Institution :
Corporate Technol., Siemens AG, Erlangen, Germany
Abstract :
The application of intense pressure pulses on two industrially interesting applications, i.e. noncontact, ultra-pure milling/deagglomeration of powders, end noncontact removal of SMD parts from printed circuit boards, is presented, including threshold process parameters. The grinding efficiency of powders (in terms of decreasing particle mean diameter per unit energy consumed) increases strongly above a threshold pressure, indicating that a further decrease of the measured specific energy consumption of this process is feasible. Application of a series of shocks to cemented or soldered SMD connections results in crack formation and propagation within the bond region, and eventually to the removal of the SMD part itself. Processing is done in a liquid environment (i.e., degassed water, silicon oil or hydrocarbons like alcohols), and can be used for either parts recycling, PCB repair, or process control in terms of online bond quality evaluation. Initial results are given concerning threshold parameters for soldered connections. This process opens up a vast field of applications, in particular in the area of rapid on-line testing and quality control in a variety of industrial processes.
Keywords :
electrical discharge machining; printed circuits; pulsed power technology; recycling; soldering; surface mount technology; PCB repair; bond region; cemented SMD connections; crack formation; crack propagation; industrial processes; intense pressure pulses; noncontact SMD parts removal; online bond quality evaluation; parts recycling; powders grinding efficiency; process control; pulsed power technology; quality control; rapid online testing; soldered SMD connections; threshold parameters; Bonding; Electric shock; Energy consumption; Energy measurement; Milling; Particle measurements; Powders; Pressure measurement; Printed circuits; Pulse circuits;
Conference_Titel :
Pulsed Power Plasma Science, 2001. PPPS-2001. Digest of Technical Papers
Conference_Location :
Las Vegas, NV, USA
Print_ISBN :
0-7803-7120-8
DOI :
10.1109/PPPS.2001.1002031