effect of electrical bias on solder cracked

C

cinderella1

Member

• Oct 29, 2013

• #1

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

Well-Known Member

Most Helpful Member

• Oct 29, 2013

• #2

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.

 

C

cinderella1

Member

• Oct 29, 2013

• #3

alec_t said:

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.

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

 

unclejed613

Well-Known Member

Most Helpful Member

• Oct 29, 2013

• #4

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.

 

C

cinderella1

Member

• Oct 30, 2013

• #5

how about other examples?

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Oct 30, 2013

• #6

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

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Oct 30, 2013

• #7

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.

 

C

cinderella1

Member

• Dec 21, 2013

• #8

how to test the electrical bias on solder cracked?

 

alec_t

Well-Known Member

Most Helpful Member

• Dec 21, 2013

• #9

With a voltmeter.

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Dec 21, 2013

• #10

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

Well-Known Member

Most Helpful Member

• Dec 21, 2013

• #11

I don't think we are talking about these?

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

 

ghostman11

Well-Known Member

• Dec 21, 2013

• #12

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

 

atferrari

Well-Known Member

Most Helpful Member

• Dec 22, 2013

• #13

Or his boss...

Ritesh, feel good, you are not alone!

 

C

cinderella1

Member

• Jan 7, 2014

• #14

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

 

alec_t

Well-Known Member

Most Helpful Member

• Jan 8, 2014

• #15

Oscilloscope.

 

C

cinderella1

Member

• Jan 10, 2014

• #16

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

Well-Known Member

Most Helpful Member

• Jan 11, 2014

• #17

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

 

crutschow

Well-Known Member

Most Helpful Member

• Jan 11, 2014

• #18

Yup, I think we have a billy clone here.

 

C

cinderella1

Member

• Jan 12, 2014

• #19

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

 

C

cinderella1

Member

• Jan 12, 2014

• #20

who is billy?