Path: utzoo!attcan!uunet!snorkelwacker!usc!zaphod.mps.ohio-state.edu!mips!daver!bungi.com!news From: gs@vw25.chips.com (George Scolaro) Newsgroups: comp.sys.nsc.32k Subject: Re: Hardware Problems Message-ID: Date: 15 Jun 90 23:31:37 GMT Sender: news@daver.bungi.com Lines: 42 Approved: news@daver.bungi.com [In the message entitled "Re: Hardware Problems" on Jun 15, 13:17, Steven.D.Ligett@mac.dartmouth.edu writes:] > --- Ian Dall wrote: > The power supply and ground pins need quite a lot more heat than the > signal pins due to the large amount of copper attached to them. I > noticed this when I was soldering but I guess I didn't quite give this > one enough. > --- end of quoted material --- > Congratulations! I hope you've got it! > > At Dartmouth, we build a lot of our own hardware for our communications > network. The shop technicians build the boards at home for overtime. > Usually, I just give them a bag of parts, a blank board, and a board to copy. > My only instructions are "More heat; less solder." You don't want joints with > blobs of solder, you want joints where the solder has wicked up into the hole. Very true. Most of the ground and power pins on the PC532 use thermal reliefs. That means that the pin is not 100% connected to the copper plane but instead has small pie sections (4 of them) in each quadrant that don't contain copper. The thermal relief is intended to enable a good solder joint to be made on a wave solderer - where consistent joints are essential on all pins at a given solder temperature. For manual soldering, I generally like to have the tip well tinned and then bring it down on the pin/pad that I am about to solder. I leave it there for 1/2 or so before adding the solder. This ensures that the pin and pad/hole are heated and the solder wicks nicely down the hole. A 'nice' solder joint will always be shiny. Even though it takes a bit of work it is a good idea to clean the flux off the board after soldering with one of the commerial flux removers. Then it is much easier to inspect your handywork. The flux (resin) in electronics grade solder will not cause corrosion of the traces and pads - the reason to remove it is to make the board like 'nice' and to be able to inspect the joints. Ditto on the congats. best regards, -- George Scolaro (gs@vw25.chips.com) Chips & Technologies (408) 434-0600 3050 Zanker Road San Jose, CA 95134