effect of electrical bias on solder cracked

[cinderella1]

Solder cracked happen due to vibration, mechanical shock, thermomechanical fatigue, thermal aging and humidity. Thus it will cause an open circuit if solder joint is cracked. However, what is the meaning of electrical bias and its effect? can someone care to explain it to me. Thanks

 

[alec_t]

Electrical bias is a (usually) fixed voltage, relative to a common/ground point, applied to a circuit node. It has nothing to do with solder joint failure unless the failure is associated with that node or point.

 

[cinderella1]

Electrical bias is a (usually) fixed voltage, relative to a common/ground point, applied to a circuit node. It has nothing to do with solder joint failure unless the failure is associated with that node or point.

how if that failure is associated with that node or point?

 

[unclejed613]

for instance, if the base bias on a transistor is 0.7V, and the soldering on the transistor fails, so that the base is effectively open circuit, the bias at that point in the circuit will likely be some value much higher than 0.7V because the transistor's base is no longer connected.

 

[cinderella1]

how about other examples?

 

[Nigel Goodwin]

I don't have the slightest idea what you're on about?, there's no relation between dry joints and bias?.

 

[KeepItSimpleStupid]

You can think of "bias" as the "operating point". For example in some audio stages, the stage is biased at 1/2 Vcc. It's also generally a quiescent condition.

 

[cinderella1]

how to test the electrical bias on solder cracked?

 

[alec_t]

With a voltmeter.

 

[KeepItSimpleStupid]

Now there are such things as thermal EMF's caused by dissimilar metals, but I don't think we are talking about these?

 

[alec_t]

I don't think we are talking about these?

I don't think so either. Not sure what the OP is really talking about.

 

[ghostman11]

I have a feeling that the OP is the guy that sits on the left of billy! Or maybe his manager

 

[atferrari]

Or his boss...

Ritesh, feel good, you are not alone!

 

[cinderella1]

Besides voltmeter, what other instrument can be used to measure bias?

 

[alec_t]

Oscilloscope.

 

[cinderella1]

can i use diode to test electrical bias? for eg: i apply forward and reverse bias on the diode to see the effect

 

[alec_t]

What are you biasing? What has this to do with 'solder cracked'?

 

[crutschow]

Yup, I think we have a billy clone here.

 

[cinderella1]

what is the best temperature cycle to crack a eutectic solder?

 

[cinderella1]

who is billy?