Surface cooper probe SRP-4 Application:
The SRP-4 Probe is used on Hitachi (Oxford) instrument CMI700 and CMI563 to test the surface cooper thickness.
Surface copper (SRP-4 probe) test principle
Surface Cu SRP-4 probe Measured by the principle of microresistance, the SRP probe has four probes, the two probes on the outside are a constant current source, and the two probes on the inside are a voltmeter. When measuring, four probes must simultaneously contact the copper surface to form a loop. According to the formula R=U/I, the resistance R can be obtained, and then the copper thickness can be calculated according to R=p×L/S. It can be seen that the copper thickness at this time has a great relationship with the size of the cross-sectional area.
Hitachi SRP-4 probe parameter:
Chemical cooper:10 μin – 500 μin (0.25 μm – 12.7 μm)
electroplating cooper:0.1 mil – 6 mil (2.5 μm – 152 μm)
lind with range:8 mil – 250 mil (203 μm – 6350 μm)
accuracy…