Re: IC pins
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From: Pete Norman
Hello everyone! I'm just toddling along with my build. The major problem so far has been fixing the bail to the bottom panel! What a beast! Anyway, it occurs to me (and has often occurred to me) why do we have to reform the pins on ICs? How come they aren't manufactured the "right" shape? I go into ESD-panic mode every time I have to re-form them and some have been a complete pain to match up to their socket. Anybody got a fool-proof, first-time technique for this? (Having spent six months studying the manual before starting has distinct advantages by the way....) Regards to all, Pete, g0pks. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Pete:
>Hello everyone! I'm just toddling along with my build. The major problem >so far has been fixing the bail to the bottom panel! What a beast! It's probably too late now, but the easy way to install the bail is to (temporarily) use longer screws to affix the bail and then to replace them, one at a time, with the shorter screws, once the bail has been secured. >Anyway, it occurs to me (and has often occurred to me) why do we have to >reform the pins on ICs? How come they aren't manufactured the "right" >shape? I go into ESD-panic mode every time I have to re-form them and >some have been a complete pain to match up to their socket. I wish I could respond as to why they must be manufactured with the pins 'sprung out'... seems they could just as easily be bent properly from the factory. But I'll bet some one WILL be able to offer a logical reason. >Anybody got a fool-proof, first-time technique for this? Follow the instructions in the manual. Grasp the IC by its ends, press one side down onto the desktop (I often place it against a metal ruler, for added ESD protection, though I've NEVER damaged an IC as a result of ESD) and roll the IC inward a bit, to reform the leads. They also make pin straighteners, but they're not all that much better than just doing it by hand. >(Having spent six months studying the manual before starting has distinct >advantages by the way....) Agreed. Cheers, Tom Hammond N0SS _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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At least one insertion machine I've seen that stuffs boards grabs the IC
from the outside of all the pins and automatically squeezes to make the pins all exactly the right distance apart. It sets the I.C. into the pad holes in the board, then a little ram in the center shoves the I.C. down against the board. It's critical that the pins all be set a bit wide to be certain the pins all press against the grips so no pin gets bent under the IC when it's inserted. The machine only squeezes from the outside to start the insertion. If any pin was slightly bent inward a tad too far, it'd be shoved against the board and bent under the I.C. when the 'ram' pushed it down against the board. I believe the automatic insertion machines used to put I.C.s in sockets do the same. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by ANNE NORMAN
< Anyway, it occurs to me (and has often occurred to me) why do we have to
reform the pins on ICs? How come they aren't manufactured the "right" shape? I < < go into ESD-panic mode every time I have to re-form them and some have been a complete pain to match up to their socket. This is just a wild guess. The IC's are manufactured for direct insertion in pc boards ( no sockets ) by automated machinery. The machines grip the ic's in a way that exactly positions the pins by pinching them inward a small amount. This would not work unless the leads were spaced a little too wide in the first place. *This is just a stab in the dark and I am sure there is someone on the list who actually *knows the reason. Don K7FJ _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by ANNE NORMAN
Use an IC insertion tool
It is so they don't fall out once inserted into a pc board while awaiting soldering. NRE/COLE Test Center OH-3 pcarter<at>gcfn.org or wd8qwr<at>arrl.net Philip L. Carter, WD8QWR wd8qwr@w8cqk.#cmh.oh.usa.na _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Tom Hammond-3
On Jan 4, 2005, at 9:31 AM, Tom Hammond wrote: >> Anyway, it occurs to me (and has often occurred to me) why do we have >> to reform the pins on ICs? How come they aren't manufactured the >> "right" shape? I go into ESD-panic mode every time I have to re-form >> them and some have been a complete pain to match up to their socket. > > I wish I could respond as to why they must be manufactured with the > pins 'sprung out'... seems they could just as easily be bent properly > from the factory. But I'll bet some one WILL be able to offer a > logical reason. This is actually an easy one. The pins are shaped that way in order to allow the placement machinery to grab the chip and properly place it. If the pins were straight, the chips would tend to fall out of the machine, causing lots of problems. It is interesting that some chips are not angled as much - specifically the side-brazed ceramic DIPS used in older EEPROMS. They are still angled, though. >> Anybody got a fool-proof, first-time technique for this? > > Follow the instructions in the manual. Grasp the IC by its ends, press > one side down onto the desktop (I often place it against a metal > ruler, for added ESD protection, though I've NEVER damaged an IC as a > result of ESD) and roll the IC inward a bit, to reform the leads. > > They also make pin straighteners, but they're not all that much better > than just doing it by hand. There are IC insertion devices that clamp around the DIP packages and properly align the pins while you insert them into the PCB. No idea the cost, or even current availability. They used to be fairly common 15 or 20 years ago (remember that far back, Tom? ;-) I use the "straighten it against the desk" ritual. As far as I know, I haven't lost a chip in 30 years. But then during that time I lived in South Florida, Georgia and Sillycon Valley, where the static levels tend to be fairly low (as opposed to places like Washington DC, which has its own static level, but thats another story... ;-) -Jack Brindle, W6FB ======================================================================= _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by ANNE NORMAN
As for the bail:
Tie a peice of twine around the bail and use a screwdriver or something like that to tighten it like a turniquet (not too tight). Insert it in the holes and loosen the turniquet. If you tighten it too much or keep it that way for too long, you will change the shape of the bail. Worked well for all the ones I have done. NRE/COLE Test Center OH-3 pcarter<at>gcfn.org or wd8qwr<at>arrl.net Philip L. Carter, WD8QWR wd8qwr@w8cqk.#cmh.oh.usa.na _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by ANNE NORMAN
If your local humidity is kept above 50 per cent RH, you can grasp the pins
of any IC and gently squeeze them to close them to fit sockets. I usually lay them sideways on the desk top and put pressure on them, holding the plastic or ceramic body. This is the safest way. -Stuart K5KVH _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by ANNE NORMAN
I use a pair of long-nose pliers, long enough to encompass
all the pins on one row of the chip. You want the pliers close to and parallel with the body of the chip. Then gently bend toward the center of the chip until the pins are straight. Repeat for the second row. Works like a charm. Doug W6JD ----- Original Message ----- From: "ANNE NORMAN" <[hidden email]> To: <[hidden email]> Sent: Tuesday, January 04, 2005 9:22 AM Subject: [Elecraft] Re: IC pins From: Pete Norman Hello everyone! I'm just toddling along with my build. The major problem so far has been fixing the bail to the bottom panel! What a beast! Anyway, it occurs to me (and has often occurred to me) why do we have to reform the pins on ICs? How come they aren't manufactured the "right" shape? I go into ESD-panic mode every time I have to re-form them and some have been a complete pain to match up to their socket. Anybody got a fool-proof, first-time technique for this? (Having spent six months studying the manual before starting has distinct advantages by the way....) Regards to all, Pete, g0pks. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by ANNE NORMAN
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0&rd=1&ssPageName=WD2V May be of interest to you John > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of ANNE NORMAN > Sent: 04 January 2005 17:23 > To: [hidden email] > Subject: [Elecraft] Re: IC pins > > From: Pete Norman > > Hello everyone! I'm just toddling along with my build. The > major problem so far has been fixing the bail to the bottom > panel! What a beast! > > Anyway, it occurs to me (and has often occurred to me) why do > we have to reform the pins on ICs? How come they aren't > manufactured the "right" shape? I go into ESD-panic mode > every time I have to re-form them and some have been a > complete pain to match up to their socket. > > Anybody got a fool-proof, first-time technique for this? > > (Having spent six months studying the manual before starting > has distinct advantages by the way....) > > Regards to all, Pete, g0pks. > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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