Heat from circuit chips | GTAMotorcycle.com

Heat from circuit chips

N

nobbie48

Well-known member
Site Supporter
I fixed an electronic instrument (TDR) for a friend, basically open the case and push one of the circuit chips back into the socket. I keep telling him that when he drops it he should alternate sides to minimize the fall out. :)

It would be very easy to put a piece of foam rubber between the chip and the panel face but wasn't sure of heat build up or other consequences. I have no idea of what the chip does beside looking like a Lego centipede.

Thoughts? Replacement is $5,000 so I don't want to be hasty.
 
nobbie48 said:
I fixed an electronic instrument (TDR) for a friend, basically open the case and push one of the circuit chips back into the socket. I keep telling him that when he drops it he should alternate sides to minimize the fall out. :)

It would be very easy to put a piece of foam rubber between the chip and the panel face but wasn't sure of heat build up or other consequences. I have no idea of what the chip does beside looking like a Lego centipede.

Thoughts? Replacement is $5,000 so I don't want to be hasty.
Click to expand...
Use a thermal pad. Assuming it doesnt have fans inside that sound like jet engines and the gap is 1/4" or less chip will probably run cooler with the thermal pad transfering heat to the panel. If the gap is bigger, things get a little more complicated and I would be using an aluminum or copper block to make up most of the space with a thin thermal pad to stick it to the case and thermal compound between the block and chip.
 
Last edited:
nobbie48 said:
I fixed an electronic instrument (TDR) for a friend, basically open the case and push one of the circuit chips back into the socket. I keep telling him that when he drops it he should alternate sides to minimize the fall out. :)

It would be very easy to put a piece of foam rubber between the chip and the panel face but wasn't sure of heat build up or other consequences. I have no idea of what the chip does beside looking like a Lego centipede.

Thoughts? Replacement is $5,000 so I don't want to be hasty.
Click to expand...
That's one expensive megger! You can use thermally conductive silicone sponge.

CPU Thermal Pad​

 
If the chip package doesn't have anything on it already (i.e. just a regular black square) then if it generates heat most of it is getting dissipated through the board anyway. If there's not too much clearance between the chip and panel, you could get fancy and get a silicone thermal pad, cut it to size, and then the chip might actually run cooler. When you say lego centipede, I'm picturing a DIP chip - really it should be pretty difficult to knock one out of a socket, normally it takes a bit of force to pry them out.

Could also try putting a dab of hot glue under the socket IF there no SMT components in that space, think it would be a bad idea if there were though.

Edit: Also if you took a photo of the chip, there might be a part number on it - you could use that to look up a datasheet and see if there is a published TDP for it (heat output)
 
robmack said:
Are there any markings on the chip to indicate what it is? That goes a long way to figure out if it needs to dissipate any heat.
Click to expand...
It may be simpler than that. If this is a portable instrument that runs on batteries, there cant be much heat there. Even a few watts would be surprising in that case. Given that the manufacturer put nothing on it to act as a heat sink that seems plausible. The trick is to provide some.mechanical restraint without making things thermally worse.
 
My first question is....why is the chip unseating so often to begin with? I'm assuming you were just joking about him dropping it?

Next most common reason for unseated chips or broken solder joints is thermal cycles. If this is something that can be just left powered up vs powered on and off lots of times, that will eliminate the thermal cycles, and that tends to be easier on electronics.
 
PrivatePilot said:
My first question is....why is the chip unseating so often to begin with? I'm assuming you were just joking about him dropping it?

Next most common reason for unseated chips or broken solder joints is thermal cycles. If this is something that can be just left powered up vs powered on and off lots of times, that will eliminate the thermal cycles, and that tends to be easier on electronics.
Click to expand...

He has dropped it several times. He also leaves electronic stuff in the back of his pickup, no cap and raining.
 
You must log in or register to reply here.

Back
Top Bottom