Chip Shortages, Part Rescues, And The Green Tinkerer
The tinkerer is the hobbyiest (not a mythical character from the LOTR, woke though it has been morphed). We are talking about the person who loves to tinker and build new things with electronics. Recycling is the green way to go, after all. In addition, you can’t buy new parts now.
PSOC Shortages
PSOC5LP cannot be found at Infineon. It cannot be found at Distributors, worldwide.
Some PSOC3 parts are available at Distributors. Some PSOC4 parts are available at Distributors.
You want to play with a decent processor. Today, a part being available at the Distributors is a strong indication that that part is not desirable. So what can you do?
Sneaky Ways To Get Parts
First, the standard warning: If you attempt this, you literally can burn down your house, your city, and perhaps your country. SO BE CAREFUL. DON’T START FIRES.
Second, this only works because of ROHS and lead free solder constraints imposed on the semiconductor industry by governments. Lead based solder will work, but at lower temperatures, and the older components may be destroyed by higher temperatures if they were manufactured pre-ROHS.
Ok. We are talking about rescuing components off of boards. It is much easier to rescue surface mount components than through hole components. The goal is to avoid part damage as we “rescue” these parts from a life of electronic slavery.
Rescue Step 1
Be Careful! You could burn the house down.
If possible, spend money on a reflow oven. The T962A oven works, with issues. It is available at the largest online retailers worldwide. There are some instruction out there on how to update its firmware to make it a more accurate oven. For our purposes, I suspect an unmodified oven will work.
If you can’t get a reflow oven, purchase something like a Black and Decker Infrared Oven. The Infrared Quartz lamp is the key. If you do this, you will have to bypass the front temperature control, as the oven temperature will have to rise to 260 Degrees Celsius (510F), at least for a brief period of time. Purchase a good thermometer with probe to place next to the board in the oven to monitor temperature rise process.
If neither of those are an option , invest in a heat gun that can reach around 500 Degrees F. This way will be more stressful to the parts, but it will work.
Be careful! You can burn the house down.
Rescue Step 2
Place the board containing the parts you wish to remove into an oven. Bake the board at a temperature of about 150 Degrees F to 200 Degrees F for about an hour. DO NOT EXCEED 200 DEGREES F.
The purpose of this is to evaporate all of the water from the small cracks that show up in semiconductor devices.
Rescue Step 3
If you are using a reflow oven, start the standard solder reflow profile that brings the temperature up to about 263 Degrees C. This will convert any water on the board(s) to steam. It will also melt the solder on the board, making it possible to remove the parts.
At the top of the temperature curve, stop the oven. Reach in and bring the board out using tongs or heat resistant gloves, flip it over so the part to remove is facing the bench top and tap the board. The part(s) should fall off. Don’t touch them until they are at least body temperature.
If you are using a B&D oven, when the temperature reaches over 510 degrees F (260 C) then pull the board out and tap it, same as above.
If you are using a heat gun, when the solder appears silvery and liquid, perform the same action.
If possible, DO NOT pull the component off with pliers or tweezers. The thermal shock of (relatively) cold metal contacting the hot IC’s package will create thermal stress fractures in the part, leading to failure in the future.
Rescue Step 4
Put the part(s) on a new board and reflow with the oven (or solder by hand).
I have a success rate of over 90% with these steps. Sometimes the parts will fail in a few months. To bring these failure modes forward, operate the boards while being placed in an oven at a temperature of 140 Degrees F for 48 hours. If the board fails, power down and stop the test.
This action will reduce the field failure rate by close to a factor of 10. A failed component is cheapest to repair before it leaves the premises. Costs rise a factor of 10 or more when the component fails in the field. Don’t give yourself a bad name with failed components.
Fini
As much as you can, enjoy this perfect storm.
About The Author
W Maxfield
Firmware/hardware Engineer for too many years.