Hi P-A,
Those are very nice looking boards. Care is required with gold and soldering though. Check out this PDF file relating to gold embrittlement of solder joints.
Those are very nice looking boards. Care is required with gold and soldering though. Check out this PDF file relating to gold embrittlement of solder joints.
Hi Hugh,
I'm not a mechanical guy, so I'm certainly no expert on this. But I used to work in the aerospace industry, and I remember the problem from there. Back when they were using discrete, leaded components, all components with gold-plated leads had their leads dipped in a solder pot before being installed on the boards. I'm not sure why this helped, but that's what they did.
I'm not a mechanical guy, so I'm certainly no expert on this. But I used to work in the aerospace industry, and I remember the problem from there. Back when they were using discrete, leaded components, all components with gold-plated leads had their leads dipped in a solder pot before being installed on the boards. I'm not sure why this helped, but that's what they did.
Andy,
I'd guess it's a phase change issue, which is related to how quickly the solder cools. Dipped into a solder pot, the temperatures are more uniform through the lead, and will thus cool slower on withdrawal, and this could reduce the embrittlement at subsequent installation because the operation would then be much quicker since it's already tinned.
Those microphotos were alarming, with shear lines like a broken ice sheet. No wonder the SMDs literally fell off the board.
Hugh
I'd guess it's a phase change issue, which is related to how quickly the solder cools. Dipped into a solder pot, the temperatures are more uniform through the lead, and will thus cool slower on withdrawal, and this could reduce the embrittlement at subsequent installation because the operation would then be much quicker since it's already tinned.
Those microphotos were alarming, with shear lines like a broken ice sheet. No wonder the SMDs literally fell off the board.
Hugh
peranders said:
Looks good. Used a similar circuit for impedance transformations in long wave receivers to couple Hi-Z tuned loops to Lo-Z antenna connections. If you do the work right, pay attention to layout and component quality, it'll work from DC to ~100MHz. Quite a bit more than needed, but it's almost impossible to get overdrive that'll cause cross modulations.
So, is that what you're doing here?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.