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Author Topic: red stuff on a board  (Read 3251 times)

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Offline siliconmixTopic starter

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red stuff on a board
« on: January 28, 2012, 06:54:43 pm »
i noticed this red glue like substance underneath components on a board i removed from a photocopier anyone know why it's there ?
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Offline Short Circuit

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Re: red stuff on a board
« Reply #1 on: January 28, 2012, 07:02:36 pm »
That is glue, which holds the SMD parts in place during the wave soldering.

http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=723077
« Last Edit: January 28, 2012, 07:06:46 pm by Short Circuit »
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Offline siliconmixTopic starter

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Re: red stuff on a board
« Reply #2 on: January 28, 2012, 07:41:12 pm »
thankyou short circuit.thats the first time i've seen that on a board.
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Offline sonicj

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Re: red stuff on a board
« Reply #3 on: January 28, 2012, 08:23:00 pm »
also used to prevent damage from vibration, shock, handling, etc....

NASA Worksmanship: ADHESIVE BONDING/STAKING
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Offline siliconmixTopic starter

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Re: red stuff on a board
« Reply #4 on: January 28, 2012, 08:32:23 pm »
cool.it's odd there where about 6 boards in the photocopier .the glue was only used on one side of one board.perhaps they ran out :)
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Offline G7PSK

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Re: red stuff on a board
« Reply #5 on: January 28, 2012, 09:47:10 pm »
In the mid 90's there was a problem with Yaesu radio equipment going out of tune or even failing due to the glue being used on the SMD's expanding from the heat during the wave soldering and lifting the components of the board.
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Online Psi

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Re: red stuff on a board
« Reply #6 on: January 28, 2012, 11:16:11 pm »
Quote from: siliconmix on January 28, 2012, 08:32:23 pm
cool.it's odd there where about 6 boards in the photocopier .the glue was only used on one side of one board.perhaps they ran out :)

It's also possible that the board was reflowed, only components on the bottom would be at risk of falling off.
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Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline mobbarley

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Re: red stuff on a board
« Reply #7 on: January 30, 2012, 09:07:07 am »
Or with selective wave soldering only a strip of components on one side might be glued.
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