Tool for "setting"IC leads.?

Thread Starter

daba1955

Joined Apr 27, 2019
130
Probably the right forum, but possibly a bit OT

Years ago, I used to use an insertion tool for "setting" the leads of DIP ICs straight and parallel. I only had a 0.3" 16-pin one, because that's all we needed.

I'm just wondering why they can't be, or aren't, made that way in the first place, after all the manufacturer's state the lead-spacing for PCB design, but don't deliver them to that spec., being splayed out so they won't go in a board without being "doctored".
 

Delta Prime

Joined Nov 15, 2019
1,191
Hello there :)
Dual in line package integrated circuit
DIP packages are hermetically sealed package. The lead pitch is 2.54 mm
(100 mil) and the package body is made of ceramics. Metal or glass maybe used as a sealing material
Standard DIP packages are most widely used. The lead pitch is 2.54 mm (100 mil), and the spacing between terminal rows is 300, 400, or 600 mil
Skinny DIP packages are standard DIPs with spacing between terminal
rows of 7.62 mm (300 mil) and with 20 or more pins.
Shrink DIP packages are standard DIPs with a lead pitch reduced to 1.778 mm (70 mil). They are smaller in external size than standard DIPs and
suited to compact electronic equipment using high-pin-density IC packages
ZIP packages are featured by the leads which are drawn out from each
package body into a single row to allow vertical mounting with a lead pitch of 1.27 mm (50 mil). The leads of each package are Zigzag folded, within the package surface thickness, into two rows. The Zigzag folding increases the lead pitch in each row to 2.54 mm (100 mil).
 

hrs

Joined Jun 13, 2014
351
I'm just wondering why they can't be, or aren't, made that way in the first place, after all the manufacturer's state the lead-spacing for PCB design, but don't deliver them to that spec., being splayed out so they won't go in a board without being "doctored".
I believe manual and automated insertion tools can be used to put ICs in place. Then the leads spring back, seating the ICs and make them not fall out of the PCB even if you hold it upside down.
 

Irving

Joined Jan 30, 2016
2,311
That's exactly so; 30+ years ago I worked on the production line for a major UK minicomputer manufacturer (yes, there was one) and the auto-insertion system was compressed air driven. It would need tweaking every so often if the ICs were from a different manufacturer. You weren't allowed to mix chips between suppliers in case the line stalled. Nowadays with SMD parts it's no longer an issue.
 

dl324

Joined Mar 30, 2015
13,534
I'm just wondering why they can't be, or aren't, made that way in the first place, after all the manufacturer's state the lead-spacing for PCB design, but don't deliver them to that spec., being splayed out so they won't go in a board without being "doctored".
This is something not mentioned by all manufacturers; at least not easily found.

This is from a TI databook circa mid 1970's:
pdip-mechanical.jpg

Some packages other than PDIP have them straight.
 

Irving

Joined Jan 30, 2016
2,311
Yes, the ceramic packages were typically MIL-spec and we used them on special-order equipment but the boards had to be hand assembled before being placed on the wave-solder machine.

I've still got a couple of RCA1802 40-pin DIP ceramic packaged radiation-hardened MCUs c1982....
 

Jim@HiTek

Joined Jul 30, 2017
50
That's exactly so; 30+ years ago I worked on the production line for a major UK minicomputer manufacturer (yes, there was one) and the auto-insertion system was compressed air driven. It would need tweaking every so often if the ICs were from a different manufacturer. You weren't allowed to mix chips between suppliers in case the line stalled. Nowadays with SMD parts it's no longer an issue.
SINCLAIR! Loved their little devices.
 

Deleted member 115935

Joined Dec 31, 1969
0
HI @daba1955

Like many things, why the legs of the IC's always pointed out , is to do with real world.
Its relatively easy to make an auto insertion machine that can "squeeze" the pins together,
its another level of complexity to make a machine that can either expand or squeeze,

Back in the days, it was much easier to make the chips with pins bent out, sort of about right, and then the machine to exactly set them. If they had to be set exactly at manufacturing, there is chance in all the manual handling that the pins might be bent to far in or out,

With the SMD stuff of now, PQFP etc, legs getting bent is still a problem, but luckily by then a lot more automation had come in to protect the little things.

Its one advantage of BGA's
 
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