Connector vs. Solder

Have you allowed cable preparation time and actually timed the operations involved?

manipulating the wire ends can be time consuming.

The failure rate will be higher for soldered cables to...so there is faultfinding and re-work to cost.

Plus my consultancy fee ...(joke)

Yes, I have timed the operation of soldering etc etc, the time for 14 soldered cables is .035 hrs which is enough for them to solder all 14. I think faultfinding and re-work would be a cost too but how do you calculate that? I already have 2% of scrap which I think is really high. What other big costs should be involved? besides your fee jeje which I think in england should be pretty expensive. How much does an factory operator get paid in england??

Sorry...don't know how much an operator gets paid...

I guess the only way you will know the re-work/scrap rate is to monitor it.

Maybe some sort of incentive for low scrap/re work rates?

Seems to me that from a "visible cost" point of view you've already figured out that soldering is cheaper.

Perhaps the important factor between soldering and using connectors is function, not cost: are there production steps (or even post-sales occasions) that would be facilitated by having a connector rather than a soldered joint?

Things come to mind that maybe for you are no-brainers (I don't work in the PCB manufacturing industry) - such as the cost of the solder; the electricity cost for maintaining a flow solder bath (or gazillions of soldering irons); the amortized cost of accidents when hot equipment is in use near people.

There are other time-based costs that you haven't referenced: if you're using flow soldering, then (presumably) these 14 cable joints can and should be soldered as part of the flow process - adding little or no extra time; if you're using a manual process, then who does what, and when, may be a more critical time management concern: picking up the tool, the connector pieces, etc. per cable may be a longer operation than prepping a wire for soldering.

Here are some more questions:

• Which method uses more cable?
• Which method wastes more material? (Including connectors that didn't hold on the first attempt).
• Which method produces joints that continue to work after 10,000 hours of operation?
• Is your product exposed to vibration and/or extremes of temperature?
  Plastic parts of connectors age faster when exposed to temperature extremes - raising their cost (to your customer, if not to your company directly; but customers unhappy with products that fail ultimately can make or break a company).
• Would you have to invest in new tools to work with connectors? What are the wear & tear costs on the tooling used by either technique? If you did invest in new tooling or equipment, where else in your process could you use it - and what cost savings could you realize by doing so?

I suppose that what I'm saying is that a design choice such as the one you're considering is likely broader than just the obvious materials and labor costs.

hmm, those are some good questions odessey, I will check that

thanks

Have you also considered the use of the product downstream. Is it part of a system? Is it a stand-alone product? And if so is it thrown away after failure or can it be rebuilt? Alot of the value in connectors is the ease in change outs downstream, whether it is in rework operations or with the end-user. Many designers/managements lack the vison of looking down the road. They focus only on wants in front of them at the moment and try to cut cost corners every change they get because it makes it easy to sell at the moment. Later when the inevitable "bugs" start popping up, many of these so-called "bright" decisions become "headaches" to others like production and end-users. In general, my belief is if it that portion of the product is a stand-alone type that won't have replaceable components, then soldering is definitely the way to go. Otherwise, if it was designed to have items replaced and/or repaired, then connectors are the better choice, whatever the final cost may be.

I agree. But is there a chance that maybe a connector can be used and be cheaper than actually soldering?? (Taking total cost in consideration). I think it can be cheaper when a PCB is overpopulated with components and there is a very high risk to blow them away with a soldering iron. But connectors have they're own costs and most of them come from material.

In your opinion (considering total cost), what would be the best connection option? soldering or using a conector??

Also, on your soldering costs. I see you noted the cost for soldering tips. That can turn into large difference between what you believe it to be vs. what it might end up being. I bring this up, because I once went through this issue. A company I once worked for used Weller soldering stations throughout production and cost of tips tended to be between $1 to $2. After many problems with solder quality, I was asked to find the source of the problem. It turned out that as the operators wipe the tips, there was a drop from about 700deg F to about 380deg F in the tip. In fighting with this issue in order to maintain the cycle time, the operators tended to turn up the temp setting, which didn't solve the difference in the drop, just raised the bottom end. I ended up trying out a Hakko soldering station that had a differential drop of less than 100deg and had a lockout card that prevented the operator from changing the temp on their own. The drawback was that their tips ran about $8 and they last only a little bit longer than the weller tips, but they provided a much more quality solder joint while maintaining the same cycle time. In the end, the company went with Hakko throughout production despite the cost of the tips because of the improvement in quality. I bring this up only as an example where design never foreseen this issue when costing the product, yet it became an added cost, not only on that specific product, but across all of production.

Ohh, I did not know they were so expensive!! we actually use weller and Hakko but did not know about the temperature drop. I will check on that too.

My question is, where can I find hidden big costs of soldering??

• tech. expertise; soldering is an acquired art & science
• cable prep.
• are cable specs. called out? (government/military contracts)
• does the client require certification? (example: NASA)
  
• is a jig required?
  
• correct iron tip/temperature?
• correct type of solder? (example: multi core Alloy Sn 60 non-corrosive flux)
  
• proper tinning if used
• is flux allowed?
• time per joint (will vary depending on technician skill level)
• quality control
• nicked strands during stripping?
• cold solder joint?
• lifted/burned PCB pads?

A properly trained tech. with enough experience/speed in addition to the outlined items above will generally be more expensive than a properly trained tech. with experience in crimp connections. Bottom line; which method to use will be job dependent (environmental factors, mechanical stressors, etc.)

good answer!, thank you all, now let me get it on my report hehehe. just kidding..

I will calculate all this costs to see what is the total cost of soldering