Chip cooling (DIP8)

[sparkle]

Hi guys!

I have a pair of DIP8 chips that I have to cool down. Any ideas how to do that. I have tried to glue the cooler on the top of the DIP8 but because of heat this is not working. The glue was two component glue.
regards
daniel

[mlloyd1]

I use a heat sink that came from a company called Aavid (in the US). It slides snuggly onto the minidDIP (8 pin DIP) package and worked well. I use them to cool AD811 and BUF634, which tend to run a bit warm with +/- 15V rails.

Sorry, I can't recall the model numbers

edit: but I did find a
link:

mlloyd1

[jackinnj]

http://www.aavidthermalloy.com/bin/s...m=580100w00000

[jneutron]

Originally posted by sparkle
Hi guys!

I have a pair of DIP8 chips that I have to cool down. Any ideas how to do that. I have tried to glue the cooler on the top of the DIP8 but because of heat this is not working. The glue was two component glue.
regards
daniel

You have to use a two part expansion controlled epoxy.

Bi-paks makes a two component kit, you remove this clip in the middle, then knead the two parts together.

Epoxies soften as the temp goes up, based on the glass transition temp..many regular two part epoxies are like that.

And, scuff the dip top surface to help adhesion.

The clip variety may be the way to go, as the aluminum sink expands faster than the plastic of the chip (usually), the slip on allows expansion and contraction.

Cheers, John

[jean-paul]

Heat sink glue that comes with coolers for computer VGA cards is good.

[sparkle]

Whoa!
Thanks guys!
I know that I can relly on You all!
regards
daniel

[peranders]

Originally posted by sparkle
Hi guys!

I have a pair of DIP8 chips that I have to cool down. Any ideas how to do that. I have tried to glue the cooler on the top of the DIP8 but because of heat this is not working. The glue was two component glue.
regards
daniel

What is it you have to cool down?

[sparkle]

Hi!
Peranders; I have to cool down OPA2604; I have an information now that they could be oscilating on high freq. - maybe that is the reason for my heating. I am building some headphone amps using Jan Meier schematic with some natural crossfeed. Found the schematic on www.headwize.com. Mr. Jan told me that my chip might be oscilating. I would try to eliminate that first. Schematic is attached
regards
daniel

edit; the sch is using LMxxxx and I have used OPA2604- also the power supply is Sulzer- Borbelly reg. Only the input chip is very hot.

[peranders]

This class A arrangement isn't always investigated how good it really is. I suspect that some opamps can benefit from it and others just get worse. 10 mA is rather much if you have 15 volts supply voltage. Maybe you should start with 2-5 mA instead, or just skip it?

[sparkle]

You mean to change or to remove the 1k5 resistors from output of the opa's to the power supply rails?
regards
daniel

edit:
interesting is that only the input chip is heating up- the output chip is rather cool. That might be because of the RF interferenes or something- that might stimulate the input chip to oscilate.....
Mr. Meiers told me few minutes ago that I should try to change the values of 10pF cap's to 47pF and 220pF to 680pF and also to try to add 47pF between noninv. and inv. input of the chip. Will try today but in the evening....