Solderless breadboards vs protoboards and printed circuit boards

T&E Engineer · 2006-01-17 12:50

When I design a project it is usually on a solderless breadboard. However I have been working on a larger project with about 100 ICs and many wire cables. I currently have about half of it soldered on a protoboard. The problem is that the protoboard is starting to bend significantly (8.5 x 17") due to the weight of the IC's and more so on due to 8 wire output cables coming off of most every IC. The trouble I am seeing also is in troubleshooting all of the soldered wires (which may come off due to the heat from fixing an adjacent wire issue) to check every output cable and time spent cutting, tinning, and soldering every wire. I have decided on a new approach.

Is is "acceptable" as a long term project to have the project assembled on cascaded solderless breadboards (about 13-15)?

I have been working with solderless breadboards for years and didn't originally think this would be an acceptable format to use as an end format. The boards will be inside of a case at the end not exposed to public view unless future expansion is needed.

I also thought about having a PCB made up but it is much more expensive and harder to get one made on that big of a board.

Solderless breadboards allow for easy configuration and quick wiring (professionally look to keep wires short). Future expansion may also be needed to the design which makes this a good way to go too.

Comments?

Thanks.

Paul Baker · 2006-01-17 13:31

While you are doing inital prototype, I would likely stick with what you are doing. However to combat the fatigue of the board I would incorporate standoff headers at regular intervals to provide support for the board (will require reaming some holes to accomodate the standoff screw).

My personal preference is to migrate to PCB for the final product, as mentioned in your question about PCB design programs, you can daisy chain several different PCBs. Cadsoft's EaglePCB Lite (free) permits 3"x4" designs. If you switch to surface mount parts and dual side populate, you'd be amazed at how much you can squeeze onto a PCB.

To give you an example, the board Im presently working on has 12 QSOP24 chips (0.65 mm pitch), 192 current limiting resistors, 208 through-hole solder pads for offboard connection to LEDs, ~30 jumper resistors (0Ω surface mount resistors), 2 3-pin headers, power jack, board address setting pads and mounting holes and this is all squeezed onto a 1"x4" board.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·1+1=10

bobledoux · 2006-01-17 14:28

I've had trouble with solderless boards eventually generating high resistance contacts. It can be difficult to locate these when everything appears wired properly. For frequencies below 12mhz, I still use wire wrap for complex test layups. They are dependable and easy to correct. Wirewrap also allows easy testing of alternative hookups.

More of my projects depend on surface mount devices so I find myself building sub-boards that hold SMT devices or special critical functions like 900mhz transceivers. The sub-board holds the transceiver and its antenna. Only low frequency power and signals are run to the wirewrap board.

This approach can be useful when there remain questions about the proper functioning of sub-circuits. It can prevent difficult cutting of traces and soldering of temporary jumpers for testing purposes. However one must remember the current limits of wirewrap. I try to avoid passing more than 100ma through a #30 wirewrap wire.

I recently visited a website discussing the development of the Apple Mac computer back in the early 1980's. They wirewrapped the first five prototypes.

Post Edited (bobledoux) : 1/17/2006 2:31:53 PM GMT

Tronic (Greece) · 2006-01-17 14:45

I have the same problem having to use surface mount devices in my projects...
Take a look at one of the subboards I made to convert them into DIP-like packets...

Thanos
·

T&E Engineer · 2006-01-17 14:51

I already have the IC's (not surface mount) so this is not really the issue.

I really like the usage of solderless breadboards vs the soldering hassle of soldering methods.

More comments welcome.

Thanks.

Beau Schwabe · 2006-01-17 15:30

Lead T.E.,

Can you break down your design into functional blocks? With a modular approach, it might be easier to manage. This way you
could also stack your protoboards so that they "plug" into one another. <--Wire wrap IC sockets are good for this.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Beau Schwabe

IC Layout Engineer
Parallax, Inc.

T&E Engineer · 2006-01-17 15:40

If we do go with solderless breadboards...Does anyone know of a way to keep the shorten wires secure to the solderless breadboards (and still have access to the ICs to replace / configure if needed).

Thanks.

T&E Engineer · 2006-01-17 17:31

What about some sort of shrink wrap like how the SX-Key is. However it may not allow sufficient air flow to the IC's.

Comments?

Thanks.

kjennejohn · 2006-01-17 17:33

Radioshack(.com) has a perf board that looks like a typical breadboard, Catalog #: 276-170. Consider transfering your project to this (these?) after you have proven the circuit to be ready. It gives me the shivers to think of a final project sent out into the world on a breadboard. There's nothing more permanent than a well soldered joint. At room temperature, anyways.

kjennejohn

T&E Engineer · 2006-01-17 17:36

I was also thinking of that board too as another option but then their is the additional costs involved (15 solderless breadboads and 15 PCBs) and they are not stackable. It may still be looked into.

pjv · 2006-01-17 21:36

LTE

As a lead test engineer you ought already know that for a final product one NEVER uses a solderless board.

You used the word Professional in your first post. I can't think of anything less professional than a solderless board for a final product. If someone "Professional" tried to pass that off on me for a final product, I'd fire them on the spot!

So, there's my answer to your question.

Cheers,

Peter (pjv)

T&E Engineer · 2006-01-17 21:45

OK I get your point. I have already sugested to the other party that we go with the Radio Shack solderable breadboards (overlay of their solderless breadboard) as another option. It will be in his hands to cancel the order of the solderless breadboards and order the solderable breadboard (PCBs).

Thanks.

bobledoux · 2006-01-18 13:45

Tronic: What do you plug your little boards into, DIP sockets or header sockets? I prefer to use machined DIP sockets and they don't often take the square pins very well.

Tronic (Greece) · 2006-01-18 14:11

bobledoux said...
Tronic: What do you plug your little boards into, DIP sockets or header sockets? I prefer to use machined DIP sockets and they don't often take the square pins very well.

I usually plug them on·header sockets but I sometimes plug then on solderless boards too without apply·much force...

Below are the headers I usually·plug it on boards I constructing... (I couldn't find a better one right now to show you...)

Thanos

LoopyByteloose · 2006-01-18 14:43

Wirewrap is still the best for fairly complex constructions.
Flexible, yet nearly permanent.

If you make a mistake or want to redesign - you just unwrap the wire.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)

······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

Paul Baker · 2006-01-18 19:15

Kramer said...
Wirewrap is still the best for fairly complex constructions.
Flexible, yet nearly permanent.

If you make a mistake or want to redesign - you just unwrap the wire.

Yeah except if you have a large design where there can be 3+ connections per post, and you discover a problem you can end up rewiring many different posts. I discovered one setup where the bottom wire on a post was wired wrong, I had to unwire the 3 above it, and to make a long story short, the cascade effect caused me to unwire more than 20 wires on more than 30 posts, just to fix one connection

.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·1+1=10

SN96 · 2006-01-18 19:33

That's the problem; wires under wires cause a potential nightmare. I would rather deal with SBBs, but sometimes these can be a pain where wires sometimes pop out without you knowing about it.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Mike

·

Paul Baker · 2006-01-18 23:29

SN96 said...
·I would rather deal with SBBs, but sometimes these can be a pain where wires sometimes pop out without you knowing about it.

Or when specific holes fail to make proper connections anymore, in college I had a friend who used his uncle's· breadboard from when he was in college in the late 70s·and the thing was pockmarked with red dots everywhere (red felt tip pen) which his uncle and he used to signify holes which no longer worked. The ones where 0.3" ICs fit into where a particular nightmare to work around.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·1+1=10