What bad glue can do to the board

[Th3_uN1Qu3]

Re: What bad glue can do to the board

Hot glue FTW.

[c_hegge]

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.

For the coils, maybe. But at least they usually have insulation around the wire, so conductive glue isn't much of an issue there. For capacitors and transistors, though, there is no need to glue them in place, as they don't vibrate (and they're not heavy enough to put much stress on the soldering either).

[TechSuperDave]

Re: What bad glue can do to the board

Hot glue FTW.

That's what we use in my shop after repairs.

Never had an issue with it.

[lexwalker]

Re: What bad glue can do to the board

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).

More degraded glue horror stories. Have encountered plenty of such cases in many different equipment ranging from monitors, speakers to even everyday household appliances. The electronics industry is fond of them, and at least always gave us something (usually a mess) to work on (cleaning up and fixing that mess)...

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.

That's very incorrect. The degraded glue plague itself can cause problems (by being conductive and corrosive) and it does not have to be high voltage (for example, many audio amplifier and speaker systems suffers from this degraded glue causing malfunctions and brown outs)...

[Kiriakos GR]

Re: What bad glue can do to the board

That's very incorrect. The degraded glue plague itself can cause problems (by being conductive and corrosive) and it does not have to be high voltage (for example, many audio amplifier and speaker systems suffers from this degraded glue causing malfunctions and brown outs)...

This glue is added as mechanical support over components which possibly are in risk due vibrations, which eventually will cause damage to their soldering leads.

One strong chemical reaction needs two hostile recipes in the mix.
The one recipe is the glue (chemical composition) the other is the varnish (chemical composition) which the manufacturer of one electronic part selected to use as additional protection against corrosion by humidity.

In manufacturing, tests regarding dielectric straight of chemical compositions, or if a part it does met it specifications regarding electrical isolation, it is in the hands of engineers.

If they do their job properly? Then there is no problem.
One of my huge enemies as thinker repair man, is this tendency of some people about generalizing and jump in conclusions, based on very few experiences of their own.

Even the industry of true hole resistors (for example) have update with out public notice the manufacturing process and materials, so the new components to become environmentally friendly.

And I am coming today to ask you all?
Which evidence and standards we are going to use so to come down in a conclusion?
1) The ones before 20 years?
2) The latest?
3) The work done in a single factory which did not comply to any manufacturing standard ( American or European ) regarding the use of safe parts and workmanship ?

Such important conversations have value if the participants qualify enough so to offer answers, instead of opinions.

[budm]

Re: What bad glue can do to the board

"One of my huge enemies as thinker repair man, is this tendency of some people about generalizing and jump in conclusions, based on very few experiences of their own."
It is obviously that you have not learn or done any more research abut this glue problem, more than one factories used these glue in the past.
From the article:
A Google search for “conductive brown glue” finds more than 100,000
references, some of which mention the glue’s role in various CRT display
problems and its use in consumer audio equipment. Searching for
“chloroprene adhesive,” Google finds 56,000 references, including one from a Sony division that contains the
following cautionary note: “The products…contain chloroprene rubber…. Prolonged standing in a high-temperature
environment…may cause thermal dechlorination, possibly resulting in the corrosion of metal parts nearby, or in a loss
of insulation resistance. Please be sure to avoid any use of these materials in electronic components that are to be
energized electrically to prevent tracking or similar problems.”
You also never use conformal coating since you claim "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."
Time for you to change from "PRO" to "Knowledge seeker" and learn what the creepage and clearance are about.

From the Greek web site: "Due my unexplained insistence about perfect ness, and about learning new things almost daily, usually I can reach subjects close to the level of engineering. I have helped lots of trainees to advance fast in the job, by using the “Kiriakos teaching method”, which is to use small stories of unrelated examples, but with common essence. ( In a way, what Jesus did). " Just like Jesus eh!
http://www.ittsb.eu/about.html

[lexwalker]

Re: What bad glue can do to the board

...

Sometimes pictures can tell a thousand words. Do these pictures tell the story? Once a while I would take some snapshots of degraded glue and the carnage...

[budm]

Re: What bad glue can do to the board

@lexwalker: No, that is not good enough evidence for the Greek, and since you do not have "PRO" in your sig, he cannot take you seriously and tell you that you are just a kid at the key board. He needs to teach us " In a way, what Jesus did"

[mariushm]

Re: What bad glue can do to the board

I'm surprised you guys didn't learn already to just ignore him. I'm not wasting my breath and my fingers on him anymore...

[budm]

Re: What bad glue can do to the board

More example.

[ben7]

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).

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.

I half agree. With lead-free stuff, you need that glue, since that stuff is so brittle. Usually extra large components should have extra pins for more stability on the board, like those 4 pin snap-in capacitors.

I'm surprised you guys didn't learn already to just ignore him. I'm not wasting my breath and my fingers on him anymore...

I'd say the same, if someone is bothering you, just ignore. If they keep bothering you, then report them.

Hot glue FTW.

Totally!

[Kiriakos GR]

Re: What bad glue can do to the board

"
A Google search

Stick to your favorite Google search, mostly because is free of charge.

[budm]

Re: What bad glue can do to the board

"Stick to your favorite Google search, mostly because is free of charge." So, please tell us more Jesus!

[kc8adu]

Re: What bad glue can do to the board

stop feeding the troll and it will go away.only reason kirakos is not on ignore here is because i am a moderator charged with enforcement of forum rules.

[int0x13]

Re: What bad glue can do to the board

Hello badcaps, i was reading this thread and found it interesting because i encountered the same yellow glue (i think) in a Klipsch Audio Amplifier, can you confirm it is the same thing:
http://i.imgur.com/L14Q8.jpg
Id like to know which tool and which chemical cleaning solution do you recommend to remove this damn glue? I had a horrible plain to remove it but i think i used wrong method (i used cutter and tweezers). Thx.

[budm]

Re: What bad glue can do to the board

I use Alcohol to soften them first, it does take awhile, you can also use small cutter to trim it off as much as you can, scraping with small thin blade also help, just take your time.

[Lumberjack777]

Re: What bad glue can do to the board

I have never encountered the glue problem. I guess I'm lucky in that respect. On certain video chips that are BGA (ball grid array). I have oftentimes encountered glue surrounding the entire chip. I have a hot air station, and I just heat the glue and peel it away with a dental pick. Does hot air not work with this type of glue, to soften it?

[Th3_uN1Qu3]

Re: What bad glue can do to the board

No. That's exactly the thing - with heat, the bad glue turns from yellow to brown and becomes corrosive and conductive. It also hardens rather than softens, making it break in little pieces when you scrape it off.

[int0x13]

Re: What bad glue can do to the board

Ok, so isopropyl alcohol (that i use to clean flux on PCB) should be used. I had tried acetone and it wasnt working at all. I also tried hot air (with my SMD rework station) without any luck too, this glue cant melt even with high temperature.
Based on my reads it contains chloroprene or melamine material, right?

[ReeceyBurger123]

Re: What bad glue can do to the board

Yet again im bringing up an old thread lol

I have a STA250TV psu from a 32" Bush Tv it had clumps of the horrible glue all over the place, it corroded the board that bad that it ate through the copper traces which come off the output diode to the output choke ! Crazy stuff !