How Clean is it?

Quesion:

What are some of the alternative methods for determining the cleanliness of a surface? We currently rely on the classic water break test to determine cleanliness prior to plating. Are any of these alternative methods as easy to use as the water break test? A.L.

Answer:

Yes, there are a number of alternate testing methods for determining the cleanliness of surfaces. Some of these methods are:

 

• Particle counting methods
• Contact angle measurement
• UV emission
• Scanning electron microscopy
• Ion chromatography
• Secondary ion mass spectroscopy
• Auger electron spectroscopy
• Electron spectroscopy for chemical analysis
• Total organic carbon

 

Many of these methods are required and used in the semiconductor, printed circuit board and pharmaceutical industries. None of these methods are as simple as the water break test. The test is considered a non-critical verification method. It is better than the older method of "if the plate sticks the surface must be clean" method!

Space does not permit the discussion of these various methods but a brief very good discussion of these methods as well as a number of other methods can be found at web site www.cleantechcentral.com. This site is the place to go if you require information about almost any type of cleaning method.