Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


SMT resistors

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#41985

SMT resistors | 6 June, 2006

Perhaps there is someone who can answer this question. If a 1k 1% 0805 ohm resistor is missing a corner is it still going to read 1K ohm? Or, if it has an extra bit of material is it going to read more than 1k ohm? I am guessing that when chip reisistors are made they are in a strip and then scored and separated. Is this anomaly considered a defect?

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Rob

#41987

SMT resistors | 6 June, 2006

Hi John,

They may still read the correct value initially, but they are not going to age well if the electrodes start oxidising. Also the high voltage surge performance & the impedance are likely to be effected, however these may be unimportant to your circuit.

There has been a lot of discussion on what is acceptable and what isn't depending on what manufacturer you talk to, however if you start off with calling it a defect you can look at the implications to your product in the field and work back.

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RDR

#41995

SMT resistors | 6 June, 2006

See IPC 610 for this. Section 9, there are a lot of conditions so I will not post here

Russ

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