Customer acceptance tests with multiple vendors. Not fun.
1. Do they tell you which parameter is failing and in which direction?
2. Do you have examples of the alternate parts?
Yes, on both counts.
As you can see below I thought were doing fine. Until they connect it to their circuit and an LCR meter.
the Rp falls below their spec for the completed circuit and the alternate parts from the other vendors pass and have a higher ohms reading.
But we are buying all the same materials from the same vendors not sure why we are falling short.
Spec Actual
<13 ohms 4 - 4.5 ohms
<37 ohms 11.15 - 12.64 ohms
<10 ohms 1.68 - 1.82 ohms
I'm thinking of just getting a better LCR meter with a Cp-Rp simultaneous read out so we can do the exact same test as the customer.
These numbers seem absurdly low for Rp. Are you sure this isn’t Rs? Also, as worded here, you pass the spec since your “actual” values are, in fact, less then the quoted specs. Normally, Rp would have a minimum spec and Rs would have a maximum spec, e.g. < 10 ohms.
I would agree our parts meets specs. However when our printed circuit is added to the customer device it fails Rp.
The spec has 5 test points (point 1) Rp >25 ohms = fail (points 2-5) Rp > 1000 ohms = fail.
Yet, two other vendors are not having the same issue.
I have rented a B&K Precision 894 the exact same meter the customer is using and I have a golden part from the customer.
When the meter arrives I want to see the failure the customer is complaining about duplicated using their own test.
Truthfully I suspect something is not right on their end.
Update:
It turns out they interface the printed circuit with a hydro-gel acting as a capacitor. The trouble seems to be with way hydro-gel contacts the circuit.