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Question about IC Chip's.

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wade7575

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I have been a Hobbist of building a lot of different electronic's kit's and fixing thing's like replaing blown Caps or Resistor's but there is one thing I have never been able to figure out and that's why is it when you buy a kit that use's a threw hole IC chip the hole spacing on the board is never the same for the IC Chip and if they give you a IC socket that you solder in first and then you are supposed to push the IC chip into it.

Here is what I can not understand how stupid are the company's that make the IC chip's and the socket's what point is there to making a IC socket and you still have to bend the leg's on the IC inwards because they are to wide,I really hate having to bend them as they can break very easy and plus it is a pain to get everyone bent in the same so they are all lined up.

Is there some tool that you are supposed to use to do this or some trick to doing it right,it's IC chip's like these in the icture I'm talking about,I don't have any problems with the smaller IC's it's the one's that have 10 more leg's per-side that give me the most problem's.

 

granddad

Well-Known Member
Having worked on early TTL 74 socketed boards, ( 10's of many legged beasties per board ) it was better to have a realty tight fit , as sometimes due to heat / cold / vibration they could creep out ! never straightened them just placed one side in and eased the other into place and pushed... ( happy days I could fix stuff then ) :angelic:
 

Nigel Goodwin

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Most Helpful Member
Here is what I can not understand how stupid are the company's that make the IC chip's and the socket's what point is there to making a IC socket and you still have to bend the leg's on the IC inwards because they are to wide,I really hate having to bend them as they can break very easy and plus it is a pain to get everyone bent in the same so they are all lined up.
Not 'stupid' at all, they are bent slightly outwards to hold the chips in the board once placed there by component insertion machines on assembly lines, the spring effect from the pins means the chips hold themselves accurately in place and can't bounce out.

For the same reason SM devices are glued down by the 'insertion' machines.

Although I agree, for our 'manual' techniques, it's somewhat of a pain :D

However, the pins certainly don't 'break very easily' (and I've never heard of anyone been so clumsy as to break one :D) - it sounds like you haven't thought how best to do it?. Personally I place the chip on the bench, on it's side, and bend all the pins at the same time by rolling the chip slightly.
 

spec

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Most Helpful Member
Not 'stupid' at all, they are bent slightly outwards to hold the chips in the board once placed there by component insertion machines on assembly lines, the spring effect from the pins means the chips hold themselves accurately in place and can't bounce out.

For the same reason SM devices are glued down by the 'insertion' machines.

Although I agree, for our 'manual' techniques, it's somewhat of a pain :D

However, the pins certainly don't 'break very easily' (and I've never heard of anyone been so clumsy as to break one :D) - it sounds like you haven't thought how best to do it?. Personally I place the chip on the bench, on it's side, and bend all the pins at the same time by rolling the chip slightly.
Nice summary. Rolling a DIL on its side is just what I do too.:cool:

spec
 

JimB

Super Moderator
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wade7575

New Member
I have not broken any myself from trying to force them into the socket but I have gotten a few kit's from china where one had a bent leg and every time they break very easily if they bend is to great,it seems like to me the metal does not stand up to being bent to far and just wants to break off if you try and bend it back.


Not 'stupid' at all, they are bent slightly outwards to hold the chips in the board once placed there by component insertion machines on assembly lines, the spring effect from the pins means the chips hold themselves accurately in place and can't bounce out.

For the same reason SM devices are glued down by the 'insertion' machines.

Although I agree, for our 'manual' techniques, it's somewhat of a pain :D

However, the pins certainly don't 'break very easily' (and I've never heard of anyone been so clumsy as to break one :D) - it sounds like you haven't thought how best to do it?. Personally I place the chip on the bench, on it's side, and bend all the pins at the same time by rolling the chip slightly.
 

kubeek

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Most Helpful Member
The pins are bent outwards because when an automatic insertion machine inserts them into a pcb, it pushes them together to fit the holes, but when it releases they spring back and hold the IC inside the pcb.
 

spec

Well-Known Member
Most Helpful Member
We had special hand tools that formed the legs to the correct pitch to match the PCB pads or IC sockets although I never used them. The pins on some ICs were pretty thin and feeble and easily broken. The normal dodge for a busted pin was to solder on another pin cut from a scrapped DIL chip or solder a thin wire to the remaining upper part of the pin.

I remember that when DIL packages first came out (7400) we thought that they were incredibly small and difficult to work with- how times have changed.:D

spec
 
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