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Questions relating to designing PCBs
By silic0re
Hi there,

Has anyone had any luck hand soldering the SCP1000 pressure sensor?

I tried making a special pad in Eagle with extra long traces to solder this part (sort of like a mini-shmartboard designed for the SCP1000 footprint), but after an hour and a half of sodering work I can't seem to make contact with the SCP1000. My thoughts were to pre-tin the SCP1000 pins, and the PCB traces, then, once a single pin was connected, put the board on an angle, and add solder paste and allow it to reflow 'down hill' along the trace, under the SCP1000, and to the pin. I thought I had done alright, even checking the connections with a tiny needle, but it's possible that some of the pins weren't connected, are bridged, or that the SCP1000 simply decided that it became a little too warm for it at some point.

I was wondering if anyone else has had any success with hand soldering this part. I'm wondering if I should order a few more SCP1000's and try again (perhaps with a toaster oven, if that might yield more success?), or to pick up SFE's breakout board and just wire wrap the breakout's pins onto my board.

(Just a quick aside: by hand soldering I'm referring to using a soldering iron, not a reflow station :) )

By busonerd
We didn't even bother to try - we just built a board + stencil and reflowed it. Those are tricky.


--David Carne
By silic0re
Do you think a toaster oven might work, or would that destroy the sensor too?

The soldering manual cites an IR convection oven as the prefered method, if I remember correctly. I'm assuming that the ideal case is essentially where there is very little or no air movement in the chamber (or specifically, across the sensor), and no top heat. Maybe with only the bottom element on in a toaster oven, one one might get lucky?

They do seem really tricky though. I'm thinking for the time being a breakout might be handy, until I can figure out a way of reliably soldering these things without destroying boards or sensors.
By emf
silic0re wrote:Do you think a toaster oven might work, or would that destroy the sensor too?
I've reworked three of these sensors with a toaster oven, all three came out ok. When they came to me, they had already been soldered to a board but had shorts under the sensor. I put them in my toaster oven and heat it up until the solder melted and then quickly reached in and plucked it off with a pair of needle-nose pliers. Then I spent some quality time with a soldering iron and wick cleaning off the pads on both the board and the sensor. I went back and added solder to the pads on the board, just enough to dome up slightly, trying to get them all to about the same height. Gave it a light coat from a flux pen, carefully aligned the sensor, and shoved it back in the oven. I got two working on the first try, the third I didn't line up properly the first time, but it survived this process twice.

When used as altimeters, the three sensors read within about 30ft of one another. I don't know if this is what you'd expect from properly-reflowed sensors or not. If I damaged them, it only seems to have added a constant offset.

I didn't use anything special, just a toaster oven from the thrift store, still has sesame seeds in the bottom. I try not to drop the parts down there too often 'cause it's a pain to have to pick them off the sensors :-) No fancy temperature controllers either, I just slowly ramp up the temperature with the knob on the front. I cut off half an inch of solder and put it in the oven next to the board I'm reflowing. When it melts into a ball, I know the board is pretty close to done.

I doubt the temperature killed the sensors. I had my soldering iron directly on the pads for several seconds at a time cleaning them off. I easily spent 1-2hrs on each sensor, so the breakout board is certainly worth getting if your time and sanity are something you value. If you're willing to part with one or both of the above, go for it! These things aren't quite as fragile as they look.