Are Wire Wrap Products Dying Out? 15
tie_guy_matt asks: "I was in our stockroom at work trying to get connectors so I could reproduce a circuit board that I broke (oops!) I wanted to get a 20-pin connector that I could use on a wirewrap board. The guy in charge of the stockroom said that they no longer make that type of connector for wire wrap boards. Companies are starting to produce more and more surface mount chips and less and less DIP chips. Ever try to solder a sufrace mount chip onto a homemade circiut board? There is only one company left that makes wire wrap stuff: OK Industries. If this company goes under we may no longer be able to make home made Z80 computers from parts we bought from Digikey. Are hobbiest starting to have trouble finding the parts they need? Will very small companies now have to spend a lot more money to make prototypes? Is this yet another example of how big companies are squashing the little guy?"
Wirewrap (Score:1)
Wirewrap... ugh. (Score:1)
Wirewrap was nasty nasty stuff to work with. Anything past a low to low-mid density board was hell when you had to think of doing modifications. It's still widely used in telecom (breakout panels et al) but I'm glad it's disappearing from the general electronics scene.
Surface mount is not hard to do by hand. Hell I still regularly solder 204 pin PQFP parts by hand and achieve "just about as good" results as professionally soldered. Hell I prefer soldering surface mount boards. Just don't start putting 0402 parts on the board! But SOT-23, 1206, PLCC, PQFP and even TS(S)OP packages aren't a problem unless I've had too much caffeine. And modifying or replacing SMT components is far simpler and less harsh on the board than through-hole parts.
What I find really disappointing is how fast the hobbyiest market is shrinking. Generic discretes are harder and harder to come by and the young'uns just want to play with software for the most part. CPLDs, FPGAs and ASICs remove most of the reverse-engineer-ability from larger designs and even the $9.99 consumer market has been replaced with (code protected) microcontrollers, epoxy-covered chip dice, or both.
Re:Removing SMT components without killing them? (Score:1)
Just wondering how do you remove big SMT chips without damaging them?
Same idea - heat up all the legs. If the chip doesn't have many legs I can usually do it with a broad-tip iron but if there are many legs (like that 204 pin PQFP you need to use a heat gun and be extraordinarily careful. I usually just scrap the part if it's got a lot of legs (they're almost exclusively removed only if the chip is bad anyway) -- cut the legs with an X-acto knife and remove the pins a few at a time.
Re:Wirewrap (Score:1)
http://www.ece.cmu.edu/~ee545/f00/12/xedni.html
Basically every component sits in a socket that has long pins that are square-shaped (instead of circular). These go through the board and you strip the ends off of 30-guage wire and "wrap" them around the pins (using a special wirewrap tool or gun). It's not pleasant, but it's definitely better than soldering, at least for prototyping where you need to make a bunch of temporary connections.
"Squashing the little guy"? (Score:2)
Why must this be the result of malice?
Most components sold and used will be destined for production circuit boards. Thus, wire-wrap compatible components won't make much money, but will still require the infrastructure needed to support the different packaging type.
Add to this the fact that many small companies (including the one a hundred feet from me) send their schematics out to third-party board-makers for prototyping, and the wiretap market looks pretty small.
Why would you fault companies for dropping unprofitable product lines?
For the record, I haven't had any trouble finding DIP components in my area, so this question is academic for me.
Re:Wirewrap (Score:2)
Perhaps you just need a few tips on wire wrapping [mcgill.ca]
FPGA's don't solder themselves (Score:2)
A few years ago, I built a high speed serial board. I put everything I could on the FPGA becuase I didn't want to have to deal with the interconnect. But I needed to wirewrap connections to:
1) Configuration PROM for the FPGA
2) Clock
3) Tranceiver chip
4) External SRAM
5) Edge connector
6) DB9 for the serial cable
7) 8 pin header for in circuit reprogramming of the FPGA.
8) A debug header so I could reliably connect the logic analyzer to figure out what the board wasn't working.
Out with wrap, in with FPGA? (Score:1)
Wire wrap is finally going away (Score:2)
1) The word is "hobbyist", not "hobbiest" - this may be on of the most consistently misspelled words on slashdot. Sorry for the gripe, but I just couldn't take it any more...
2) There's no grand conspiracy, and your enthusiasm for wire wrap tells me you haven't really done all that much with it. It's easy, but also fraught with problems, and pretty much useless with today's speedy hardware. Many of us have all too many war stories about hardware debugging from hell. An inordinate number of these stories involve wire wrapping...
I use wire wrap wire all the time, but I haven't actually used it for wire-wrapping in years.
Wirewrap, SMD, DIPs... (Score:2)
I run a web site (link off my main site, above) for hacking the Acer NT-150, and recently a few of our members managed to solder an SMD part in order to gain access to a "disabled" serial port (ie, the pads for the chip were there, and the socket holes were there, just those two parts were missing). It had a small number of pins (28?), and when mounting, tended to slide on the surface of the pads, because the top surface was curved. The members mentioned getting the corners tacked down, then going for the rest of the chip.
So far, three members of our group have been successful - one even managed it without any former SMD experience! I haven't got any SMT experience myself, but I am even tempted to try it out (the part is a MAX part, and can be gotten as a free sample).
I like wire wrap, but it is limited to certain designs. However, the majority of hobbiests don't tend to do high speed designs, so it hasn't been much of a problem. Anything higher, and going to a regular PCB, then to SMT designs - has tended to be the route...
Worldcom [worldcom.com] - Generation Duh!
Parts are getting too big and too fast (Score:2)
But, as the person who posed the question implied, SMT is difficut for a hobbiest to work with. One alternative is to make your own PCBs, either by etching them at home, or go to some place like APCircuits [apcircuits.com] where you can get prototype PCBs made pretty cheaply. And one hint- if you are doing SMT, get the solder mask, it will make your life very much easier.
I still wire wrap when I need to- and Digi-Key [digikey.com] has had most of what I've needed, though the little pins to mount discrete components are outrageously expensive. (In particular, the T68A bifurcated pins, with room for 3 levels of wrap, at $92.25/1000.)
Removing SMT components without killing them? (Score:1)
Just wondering how do you remove big SMT chips without damaging them? At a lab where we used to work, we use a tool which clamps around the whole chip and heats up the legs, it works ok, but we're supposed to throw away the chip after that.
Cheerio,
Link.
Prototyping (Score:1)
I've been designing and hand building boards for a long time. My personal experience with wire-wrap is not very good. I much prefer point to point (PtP) for ease of rework, more readily available sockets, and fewer holes in my fingers.
As one user commented, availability of parts suitable for simple construction are slowly dying out. Surface mount is cheaper to manufacturer (in volume), smaller in size, and generally has lower power consumption. The only advantage DIP really has any more is that in low volume it is cheaper to produce. With the lower demand for the larger parts, availability is going down (although far from gone). Cost seems to pretty much stay the same. Certain component classes have all but disappeared, such as certain types of connectors. Many of these can be worked around with DIP parts, and a little creative engineering, however.
If you have even moderate vision and stable hands, you can do surface mount at home. It takes a fine tip soldering iron, liquid flux, and patience. The old Weller WTC-201 25 watt iron is NOT going to cut it. If you do a lot of surface mount, THE iron to have is a Metcal [metcal.com]. There is no substitute. These are expensive new, but can be had as pretty good deals on eBay.
I've started a tutorial on prototyping, mostly focusing on PtP techniques. It's not compete, and the photos aren't up yet, but it can be seen at www.tinymicros.com/proto [tinymicros.com]. Ignore the pictures of the dog for now. Those will be changed to real pictures of a product I worked on as soon as I finish the current software project I'm working on. I plan to expand this to a tutorial on surface mount, how to do low cost layout, and various other techniques.
Buy a convection oven and a laser printer... (Score:2)
1. Pack up the Gerber file and send it on its way to a prototype shop, and they send you back the boards. If you can't afford the three hundred (seen it as low as eighty) bucks then laser print onto mylar, press onto FRP (or whatever) with hot iron, and etch.
2. Assuming that the proto house won't put the chips on for an extra fifty bucks, glue the suckers down, solder wash, and drop in the convection oven.
3. Take coffee break, or go back to Spice.
4. Remove cold board from oven and do other side if required. Clean off connectors and test.
As one who still has to put up with wire wrap on an almost weekly basis, I can tell you that I never want to see one of those cheezy little OK wirewrap guns again in my life. Or big bulky cards, little wire tails shorting pins when you least expect it, connections sliding off due to worn bits, oxidised connections, and once somebody's made about three layers worth of changes, trying to figure out where the other end of the damn wire goes, because they didn't write it down.
Wire wrap. Bah. It made me the man I am today...
wirewrap and SMD (Score:2)