I was visiting a customer recently and an interesting question was posed regarding ESD Analysis. What is the advantage to using the Prostat CVM-780 Contact Voltmeter as opposed to the Trek Model 347 DC-Stable Electrostatic Voltmeter?
These instruments have different technologies and are used in different ways. The Trek Model 347 instrument is a “Non-contact” bench top type requiring AC power, while the CVM-780 is a “Contact” battery operated portable measuring device, using rechargeable Nickel Metal Hydride batteries. Read more…
One thing I get asked quite often; how do I set up my Prostat PRS-801 or PRS-812 Resistance Meter for low resistance range calibration? In order to setup your Prostat resistance meter for Low Resistance Range (<10 Ohms) calibration, follow the steps below: Read more…
As early as 1985, the author recalls re-occurring discussions of the effects of puncture holes from component leads and stapling of static shielding bags.
In July 2013, the ESD Experts page on LinkedIn® started a discussion by a USA computer manufacturing company that generated participation from end users, suppliers and consultants both here and abroad. In years past, some held opinions that pin holes do not greatly affect static shielding of metallized bags. There is, however, minimal published data to fall back upon regarding this subject matter. Read more…
Working in the ESD industry, I get asked some interesting questions. One of the questions came from one of our customers regarding the advantages of using the two-point probe and concentric ring over the ordinary two probe multimeter?
A multimeter uses pointed instrument probes to measure between 2 points on a circuit assembly, or to measure continuity between 2 points. Depending on its design a multimeter measures AC & DC voltage, limited resistance — typically up to 40 Megohm (4.0×106 ohms), diode or capacitance attributes, etc.
A Concentric Ring is designed to meet two specifications for measuring and classifying packaging materials for electronic applications: ANSI/ESD STM11.11 Surface Resistance and ANSI/ESD STM11.12 Volume Resistance of planar (flat) films, wraps, bags, etc. These are either area or volume measurements – nothing at all like measurements made with pointed instrument probes.
High relative humidity (Rh) causes moisture to deposit and be absorbed by some materials. It does not eliminate triboelectric charge generation. Rather, it lubricates surfaces to reduce charge generation to some degree, and helps render material surfaces slightly more dissipative. The end result is lower charge generation and a lower residual charge. Unfortunately, Rh does not reduce charge sufficiently on ordinary materials to protect many ESD sensitive devices in critical assembly or laboratory areas. Never design your ESD control based on available humidity.
Rather, design your ESD control program assuming a low humidity (or no humidity) environment. The if Rh is available, it helps make a good program more effective. Like a special sauce heightens the flavor of well-prepared dish.
Finally, relative humidity and moisture will not eliminate charge. If it did, you would never see lightening during a thunderstorm.
Prostat Corporation’s CVM-780 Contact Voltmeter has combined the ease of using a digital voltmeter and the low input capacitance of a true electrostatic voltmeter. Being a true voltmeter means that the CVM-780 reads real voltage, it does this without confusing it with electrostatic field strength.
We’ve already gone over how to make a surface resistance measurement but how do you make a measurement for volume resistance? A volume resistance measurement is pretty similar to a surface resistance measurement with the exception of a couple of steps. Read more…
Measuring ESD controls in a production process is obviously important to your product’s quality. Why would you take the time to do ESD audits to protect your product throughout production and not your packaging materials? If you’re not quite sure how to measure your packaging materials read on because we’ll help you with making a surface resistance measurement using current industry guidelines! A surface resistance measurement will let you know if your packaging materials are static dissipative, which, is the ideal surface resistance for making direct contact with ESD sensitive devices. All it takes is a few easy steps to make a proper measurement! What would you be measuring with a surface resistance test? Read more…
As early as 1985, the author recalls re-occurring discussions of the effects of puncture holes from component leads and stapling of static shielding bags.
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