Hello there,
I am Vijetha H.N, working in an organization as a PCB Design Engineer. I have a very general query regarding board testing.
When we get the assembled boards, we usually do Impedance testing; we measure the impedance of each voltage test points w.r.t Ground to confirm that the voltage points are not shorted to Ground.
During mass production, we usually consider the impedance values observed in 1st 1 or 2 boards as reference for rest of the boards.
In case If we find a variation in the Impedance value in any of the board what will be the probable causes for the mismatch ? For example If I observe 1.5 K OHM for a voltage test point in 5 boards and If I observe 500 OHM of value in 6th board for same test point, what will be the possible root causes for this mismatch ? Please list down all possible root causes for Impedance mismatch issues in the Assembled PCB for a same test point? This will be helpful in quick debug of the boards during mass production.
Regards,
Vijetha H.N
I am Vijetha H.N, working in an organization as a PCB Design Engineer. I have a very general query regarding board testing.
When we get the assembled boards, we usually do Impedance testing; we measure the impedance of each voltage test points w.r.t Ground to confirm that the voltage points are not shorted to Ground.
During mass production, we usually consider the impedance values observed in 1st 1 or 2 boards as reference for rest of the boards.
In case If we find a variation in the Impedance value in any of the board what will be the probable causes for the mismatch ? For example If I observe 1.5 K OHM for a voltage test point in 5 boards and If I observe 500 OHM of value in 6th board for same test point, what will be the possible root causes for this mismatch ? Please list down all possible root causes for Impedance mismatch issues in the Assembled PCB for a same test point? This will be helpful in quick debug of the boards during mass production.
Regards,
Vijetha H.N