What bad glue can do to the board

[budm]

Got 6 Samsung 245bw in, 3 were fixed by just removing bad glue, other 3 are badly damaged (will have to do more repair later).

[philliesfan30m]

Re: What bad glue can do to the board

wow! thats glue? it looks like chocolate salt water taffy!

[3d0]

Re: What bad glue can do to the board

I'm a bit confused? They are smart enough not to put glue that conducts electricity.
What happened to this glue? What caused it to make such a mess?
Temperature, chemical reactions or something else?

[budm]

Re: What bad glue can do to the board

I have dealt with this glue problem since the 70's. They get old, turns dark brown then becomes conductive and corrosive.

[mockingbird]

Re: What bad glue can do to the board

Does anyone know what kind of insulation adhesive Antec uses in their Delta-built PSUs, specifically the Earthwatt D's? It's like a very dense closed cell foam. Also, what do you use for adhesive? Is RTV silicone safe to use?

[budm]

Re: What bad glue can do to the board

I use electronics grade Silicone RTV, regular Silicone RTV is corrosive due to acid content.
http://www.amazon.com/Clear-Electron.../dp/B0063U2RT8
http://www.hmcelectronics.com/produc...licones/RTV162

[mockingbird]

Re: What bad glue can do to the board

Do you think Tetrachloroethylene-based silicone will work as well as the artificially high-priced "electronics" branded stuff?

[Kiriakos GR]

Re: What bad glue can do to the board

There is no issue with the glue it self, the one who placed it over the PCB he added too much, and caused a violation regarding the Creepage distance in a HV circuitry.

[mockingbird]

Re: What bad glue can do to the board

That's absurd... Conformal coating covers the entire board. The problem lies in the conductivity of the glue, not in "creepage distance".

[kc8adu]

Re: What bad glue can do to the board

i can only assume that use of this glue is for planned failure now .
this stuff was eating traces off boards in 70's quasar tv crt socket boards in the mid-late 70's.

[goontron]

Re: What bad glue can do to the board

i can only assume that use of this glue is for planned failure now .
this stuff was eating traces off boards in 70's quasar tv crt socket boards in the mid-late 70's.

i found this glue in an apple Macintosh plus floppy drive too!

[budm]

Re: What bad glue can do to the board

I have dealt with this problem since the 70's (some of you were not even born yet, or not getting into electronics yet), it is the chemical in the glue being used, some Chinese companies still use this glue. If you have lots of experience, you will know why it has nothing to do with creepage and clearance. I also use conformer coating in my board design that are used in high moisture location. I also use potting compound on the whole board. BTW, our lab is UL and CSA certified for safety testing. Done lots of HI-POT test @> 3000V.
If the glue is not conductive, you actually increase the creepage distance.

PAGE 1-8.
But what do I know, I am just a kid playing on the keyboard:
https://www.badcaps.net/forum/showth...dge+tom&page=2

budm when you will update your ID from Knowledge Seeker to a Pro ( in 10 years) ,
then I will take you more seriously, for now you are just a kid playing with it keyboard.
By my opinion you do not own even half than the understanding of Tom regarding electronics.
From the other hand Tom goes by the book due his limited experiences which he will improve in time,
those additional experiences they will help him to improvise too by using the limits of hardware with out causing a disaster.

[Kiriakos GR]

Re: What bad glue can do to the board

I think that the nerdy Greek strikes your PRIDE for another one time.

Yes it is PAINFUL for anonymous in forum heroes to accept the fact that they are not that smart.
And before some one even think to extend his bitching attempts, he must post first his own qualification degree scanned at 100% as is when it hands on his wall.

[mockingbird]

Re: What bad glue can do to the board

Kiriakos - in this case, YOU were wrong... You incorrectly stated that adding too much stabilizing adhesive violates established rules pertaining to maintaining adequate creepage distance... budm correctly pointed out to you that not only were you wrong, but that to the contrary, high-quality adhesive enhances the quality of creepage distance.

[budm]

Re: What bad glue can do to the board

I am not bitching, when I want a good laugh, I just read that post, some one else also laughing along when they read it.
"Yes it is PAINFUL for anonymous in forum heroes to accept the fact that they are not that smart" Not that smart eh? And you are SO SMART!
We already see how much you know about safety and creepage and clearance after working all these years and called yourself a pro.

[goontron]

Re: What bad glue can do to the board

I think that the nerdy Greek strikes your PRIDE for another one time.

Yes it is PAINFUL for anonymous in forum heroes to accept the fact that they are not that smart.
And before some one even think to extend his bitching attempts, he must post first his own qualification degree scanned at 100% as is when it hands on his wall.

[budm]

Re: What bad glue can do to the board

Hi gootron, we are not that smart! You also notice that he changed the subject because he does not know how the glues are used and probably never herd of or use electronics grade Silicone RTV.

[japlytic]

Re: What bad glue can do to the board

How about Star Brite Liquid Electrical Tape?

[c_hegge]

Re: What bad glue can do to the board

I just never use glue. There's really no need to IMO. The soldering is more than enough to hold the components in place (at least on the average TV/Monitor/PC PSU PCB).

[mockingbird]

Re: What bad glue can do to the board

I don't agree... If soldering itself was enough to prevent cold joints due to oscillations, then it would never have been used in the first place... I'm aware that the adhesive is also used to keep components in place during flow soldering, but its main purpose is for high-frequency vibration absorption.