Harvesting LOC diodes.. The best way?

[dave]

So far I have stuffed up a few diodes trying to press them out.. Apparently that isn't the best way

And I am not super excited about taking to the sled with a file.

Is there a better way?

[LaNeK779]

sometime ago, dnar said something about using a quality set of lliers and a vice to break the heat sink

haven't tried it my self though


i stick to the "file" method, just grab the loc upside down on the vice, so as not to have stuff falling in the diode facet

[dnar]

Hi Dave, I have tried several methods other use, including filing/hack sawing the sides. I don't like filings anywhere near the diode so I don't use this common method.

Now I just use 2 pairs of bull nose pliers. Grip either side of the heatsink (on either short side) and firmly twist back and forwards several times trying not to loose grip. The die cast cracks and the diodes just falls out eventually. Alternately, use a precision vice to hold one side + one pliers.

If they are the more recent 815's the heatsink encloses the facet allowing you to place a small piece of tape over it if your paranoid.

Using this method my success rate has been 100% to date. Just be patient and take your time.

BTW, I remove the flexible cable before harvesting as the sled can be held in a vice. I use a medium/large tip, hold the cable with long nose pliers, hit both joints and pull gently in one speedy transaction.

[LaNeK779]

hay! using tape to mask the diode sure makes the filing method much safer

i also run a piece of cable from my vice to the ground terminal of the nearest wall plug (don;t know if it helps, i just do it and feel really "scientific" about it)

[andy_con]

i know its not the best way but works every time for me.

hacksaw cut into the heat sink, then use a flat blade screw driver to crack the heat sink.

works a treat

[dnar]

hay! using tape to mask the diode sure makes the filing method much safer

i also run a piece of cable from my vice to the ground terminal of the nearest wall plug (don;t know if it helps, i just do it and feel really "scientific" about it)

Can't hurt. I use an anti-static mat and wrist strap, as always when handling sensitive semiconductors. I don't want to hurt their feelings lol.

[LaNeK779]

well, i dont have a wrist strap, but i act like an alien and handle everything using crocodile clamps (again with the cable running to the ground terminal)

didn't have anything die on me yet

instead of an antistatic mat i use an antostatic bag from an old PC motherboard

[dnar]

well, i dont have a wrist strap, but i act like an alien and handle everything using crocodile clamps (again with the cable running to the ground terminal)

didn't have anything die on me yet

Be aware, good anti-static mats/strap don't directly bond to ground. Rather they have a series resistor. You can buy varying resistances, but from memory it's around the meg-ohm mark. The reason is simply, slow discharge.

BTW, If you ever deal with HP servers or server parts, they supply a flat fold anti-static strap made of paper and copper foil. Treated with care you can get many uses out of them. The up side is they fold up flat so you can keep them in a book, brief etc with taking up too much room.

instead of an antistatic mat i use an antostatic bag from an old PC motherboard

Ingenious!

[dave]

Awesome, worked like a charm

Have been umming and arring about getting sleds, or these other open diodes, but I think Ill get some sleds

Hi Dave, I have tried several methods other use, including filing/hack sawing the sides. I don't like filings anywhere near the diode so I don't use this common method.

Now I just use 2 pairs of bull nose pliers. Grip either side of the heatsink (on either short side) and firmly twist back and forwards several times trying not to loose grip. The die cast cracks and the diodes just falls out eventually. Alternately, use a precision vice to hold one side + one pliers.

If they are the more recent 815's the heatsink encloses the facet allowing you to place a small piece of tape over it if your paranoid.

Using this method my success rate has been 100% to date. Just be patient and take your time.

BTW, I remove the flexible cable before harvesting as the sled can be held in a vice. I use a medium/large tip, hold the cable with long nose pliers, hit both joints and pull gently in one speedy transaction.

[dash8brj]

Dremel cutoff wheel and a vice works wonders. having steady hands helps. Dont try to cut all at once, give it short taps with the dremel and allow the sink to cool down in between. Make sure the sparks fly toward the side of the heatsink where the diode facet is, not the rear. This propels them away from the facet.

Takes all of 30 seconds. Once your almost through a screw driver breaks the last bit of diecast, and opens the heatsink up like a crocodiles mouth, allowing the diode to drop out. I've done a few this way, and only killed one, as I wasnt concentrating on what I was doing. (mobile phone + 30,000 rpm rotary tool = bad idea!).

My dremel has a hole drilled in the side with a wire coming out, which earths the tool and any attachment to my ground, for static sensetive componentry. When not in use, the wire's croc clip gets clipped to the power cord insulation, out of the way.