| I'm researching SO-8 power RF device mounting methods. | | Possible mounting method | | 1. Via thru holes | | Still the thermal resistance of the PCB too high | | Do you have suggestions for mounting the component, PCB/? | Joni: What is it about your situation with the board/component/process that makes you want to explore alternatives? Dave F

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Joni Siipola

#12701

Re: SMD mounting method | 5 February, 1999

| Joni: What is it about your situation with the board/component/process that makes you want to explore alternatives? Dave F

Dave: In our case the component is placed on metalled footprint which has via holes to transfer the heat via holes to the heat sink (aluminum chassis).PCB thickness 3mm, so the via holes mounting method does not provide enough good heating. However, making the PCB thinner is difficult and expensive method as far as cost and mechanical process is concerned.

Any suggestions?

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Dave F

#12702

Re: SMD mounting method | 5 February, 1999

| | | Joni: What is it about your situation with the board/component/process that makes you want to explore alternatives? Dave F | | Dave: In our case the component is placed on metalled footprint which has via holes to transfer the heat via holes to the heat sink (aluminum chassis).PCB thickness 3mm, so the via holes mounting method does not provide enough good heating. However, making the PCB thinner is difficult and expensive method as far as cost and mechanical process is concerned. | | Any suggestions? | Joni: Oh, I get it � One of those "I shot it, you skin it" deals. So, someone designed a board that is such a thermal sink, that it�s unsolderable and you have to attach components to it, but that's not all, your attachment method must conduct electricity and have a thermal conductivity of 1.

Consider:

1 Conductive Adhesives ... check the archives for suppliers 2 Low Temperature Solder, such as, Sn43/Pb43/Bi14, which is liquidous at 163�C or In80Pb15Ag05A, which is liquidous at 150�C

Good luck

Dave F

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