Cleaning assemblies

Carry-over between injections Contaminated needle Contaminated transfer line Contaminated septum or inlet Clean or replace needle assembly Clean transfer line and heat Replace septum, clean inlet... 

Before assembling, clean the parts of the worm wheel shaft with kerosene and wipe the gear housing. Check the ball bearings for defects. Clean and Lubricate carefully before refitting. 

Removal Remove unit in reverse order of assembly. Clean bore of suppressor w/ 38 cal. bore brush as needed Shake out excess carbon particles. 

Assemble clean glass plates, aluminum oxide plates, and spacers for casting the gel. 

Open top and vacuum vapor N/A degreasers for circuit assembly cleaning, and flux and ionic residue removal Batch or in-Une vapor N/A... 

Operating Experience from Sub-Assembly Cleaning System... 

Over a total period of operation the core sub-assembly cleaning system performance was sufficiently reliable. Like with the fuel handling system it is the mechanism position indication and control system that has mostly been a trouble contributor with an impact from the process control and monitoring system. The process configuration itself is unsatisfactory since the manifold of the steam-water cleaning cells is combined with the equipment cleaning system (large capacities, risk of overflows and leaks, etc...). 

This is used to check the quality of the rinsing bath in assembly cleaning processes. The conductivity measurement indicates the amount of process-related ionic, and therefore conductive, contaminants carried over into the rinse medium. 

Lastly, the use of Pb-free solders impacts the post-assembly cleaning step (step 4) and the inspection step (step 5). The higher process temperatures can produce more tenacious flux residues that require more aggressive cleaning steps to ensure their removal. Also, the more tenacious residues affect the ability of test probes to contact test site pads on the circuit board. Poor contact can be responsible for detecting false opens on the assembly. 

---