IC replacement tricks (was Re: I have a PDP-11/34 programmer'sconsole, what should I do with it?)

From: Andreas Freiherr <Andreas.Freiherr_at_Vishay.com>
Date: Thu Mar 7 11:16:16 2002

> > Yes, I have not only heard this hint, but also tried to follow it. At
> > least with my tools, I always have trouble getting to the pins to cut.
> > There is not much room between a pin, the board, and the IC body.
> I have a set of very sharp-nosed diagonal cutters - Xcelite, ISTR. They...

Probably, that's the point: I really need to get smaller-tipped cutters.

> ... From the description
> of your problem, it sounds like you are trying to hold the dikes parallel
> to the board.

I need to, because I can't get the tips between the shoulders of the
pins: because the pins are wider near the IC body, there is even less
room between them, and my cutter won't fit in. So I can only cut closer
to the board, even if I know that this may require the board to take
higher mechanical forces, compared to cutting near the chip.

OK, you convinced me: I'll go out and find better tools. Probably time
to do so anyway: I think I bought my current ones in the 1970s.

> On multi-layer boards, it can be difficult to desolder the power and
> ground pins because the power and ground plane acts as a heat-sink. The

No problem: see my previous note about soldering iron. The 70W thing has
sufficient power, well under control, and I can switch between a
pen-shape and a screwdriver-shaped tip with no tools (provided it's not
currently at nominal temperature... ;-). For desoldering, I prefer the
screwdriver shape because it can easily transfer a lot of heat through
the flat surface. And, yes, it can help to add solder first: this can
improve thermal contact.

Andreas Freiherr
Vishay Semiconductor GmbH, Heilbronn, Germany
Received on Thu Mar 07 2002 - 11:16:16 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:35:10 BST