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Is this a cold joint problem?

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timcmi

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cold joint

I am hand soldering a flip-flop 14 pin IC to my circuit board. (Part # CD4013BE). The holes in the circuit board are .033". The circuit functions fine for about 10 minutes and then quits. I probed the pins and get a ground and Vcc at the pin. If I reheat all of the solder joints, the circuit begins to work again....but, after 10 minutes it stops. Any ideas?.....
 

VSMVDD

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sounds like your using a cheep solder
thats flux conducts when it gets cold

however a ground on the vcc rail is a direct short

i would check any decoupling caps you have
as heat traveling up a track may be is enought

especialy watch poly layer types
this kind of fault isnt usualy the chip
and is the decoupling cap ....

appart from this look to the solder itself :D
 

timcmi

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The measured Vcc and ground are on their correct pins. I stated this to show that even though the circuit does not work, These pins are still making a connection. The solder is 63/36/3 fluxless solder.
 

Verba

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Put some flux at the pins of your IC and heat it well, may be they are just dirty a you indead have a cold joint
 

    timcmi

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timcmi

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The connection problem has been fixed. The solder was not properly bonding to the IC. Flux at the pins as well as a higher heat setting at the iron rectified the problem. Thanks!!!
 

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